WO2026048590A1 - Laminate, interior material including same, vehicle component, and furniture - Google Patents

Abstract

The present invention addresses the problem of providing a laminate with which it is possible to maintain color development and friction fastness in a surface layer even after high-temperature press molding, and with which it is possible to achieve sufficient peel strength.　A laminate according to the present invention comprises a surface layer containing artificial leather and a backing layer laminated together via an adhesive resin, wherein: the artificial leather includes a fiber structure and a polycarbonate-based polyurethane; the fiber structure includes ultrafine fibers composed of a polyester-based resin containing a black pigment and/or a chromatic pigment; the polycarbonate-based polyurethane has a skeleton represented by general formula (1) and a skeleton represented by general formula (2), or has a skeleton represented by general formula (2) and a skeleton represented by general formula (3); and the backing layer is at least one selected from the group consisting of woven or knitted fabrics, non-woven fabrics, and foamed resin sheets. (In formula (1), R₁ and R₂ are each a C7-11 aliphatic hydrocarbon group and may be the same or different. In addition, (n) and (m) are positive integers, and when R₁ and R₂ are different from each other, block copolymerization or random copolymerization is carried out.) (In formula (2), R₃ and R₄ are each a C3-6 aliphatic hydrocarbon group and may be the same or different. In addition, (x) and (y) are positive integers, and when R₃ and R₄ are different from each other, block copolymerization or random copolymerization is carried out.) (In formula (3), R₅ is a C3-5 aliphatic hydrocarbon group and R₆ is a C8-12 aliphatic hydrocarbon group. In addition, (a) and (b) are positive integers, and R₅ and R₆ are each a block copolymer or a random copolymer.)

Description

Laminates, and interior materials, vehicle parts, and furniture containing the same

The present invention relates to a laminate comprising a surface layer containing artificial leather and a backing layer laminated together via an adhesive resin.

Artificial leather has superior characteristics compared to natural leather, such as high durability and uniformity of quality, and is used in a variety of fields, including vehicle interiors, furniture, miscellaneous goods, and clothing. When artificial leather is used as the surface of vehicle interiors, furniture, miscellaneous goods, etc., a laminate is sometimes formed by laminating a woven or knitted fabric, nonwoven fabric, foam resin sheet, etc., to the back of the artificial leather, which serves as the surface layer, as a backing layer, in order to reinforce the artificial leather to improve its physical properties or to provide cushioning properties.

As an example of such a laminate, Patent Document 1 proposes a flexible decorative laminate comprising a non-porous thermoplastic elastomer layer and a decorative layer containing a fiber structure disposed on the outer surface of the thermoplastic elastomer layer, with the surface layer of the thermoplastic elastomer layer and the surface layer of the fiber structure contained in the decorative layer being integrated into a composite layer. It is described that this laminate can provide a novel sheet material that has an appearance decorated with a decorative layer containing a fiber structure and has elasticity that provides a high sense of resilience when the surface is pressed with a finger.

Patent Document 2 also proposes an embossing composite material in which a flexible polyurethane foam sheet is laminated on one side of a skin material, the flexible polyurethane foam sheet having a specific thickness and a specific range of compression rate within a specific temperature range. It also describes that this composite material can provide an embossed product that is capable of forming a deep uneven design, has excellent uneven design shaping ability, and also has excellent cushioning performance and durability.

JP 2017-61051 A International Publication No. 2017/056465

When these laminates are used for various purposes, they are press-molded at high temperatures (approximately 200°C to 250°C) from a fixed shape such as a sheet to give them a shape suitable for each application.

However, in the laminate proposed in Patent Document 1, a thermoplastic elastomer is injection molded onto the back surface of a fiber structure at high temperature and pressure. Therefore, while a certain level of peel strength can be achieved by exposing the fiber structure to high temperature conditions, there is an issue of reduced color development and abrasion resistance of the fiber structure.

On the other hand, in the laminate proposed in Patent Document 2, the skin material and the flexible polyurethane foam sheet are laminated using frame lamination, and therefore the peel strength depends on the affinity between the backing material and the skin material. As a result, the range of materials that can be selected for the backing material relative to the skin material is narrow, and depending on the material selected, the peel strength may be reduced.

In light of this background to the prior art, the object of the present invention is to provide a laminate that can maintain the color development and friction fastness of the surface layer even after high-temperature press molding, while also achieving sufficient peel strength, as well as interior materials, vehicle parts, and furniture that include such a laminate.

As a result of extensive research conducted by the inventors to achieve the above-mentioned objectives, they discovered that in a laminate in which a surface layer containing artificial leather and a backing layer are laminated together via an adhesive resin, by making the fiber structure of the artificial leather contain ultrafine fibers made of a polyester-based resin containing a specific pigment, and by using a polycarbonate-based polyurethane with a specific skeleton for the polyurethane contained in the artificial leather, it is possible to obtain a laminate that can maintain the color development and friction resistance of the surface layer even after high-temperature press molding, while also achieving sufficient peel strength.

The present invention was completed based on these findings, and provides the following inventions:

[1] A laminate comprising a surface layer containing artificial leather and a backing layer laminated together via an adhesive resin,
The artificial leather includes a fiber structure and a polycarbonate-based polyurethane,
the fiber structure includes ultrafine fibers made of a polyester resin containing a black pigment and/or a chromatic pigment,
The polycarbonate-based polyurethane has a skeleton represented by the following general formula (1) and a skeleton represented by the following general formula (2), or
It has a skeleton represented by general formula (2) and a skeleton represented by general formula (3),
The backing layer is at least one material selected from the group consisting of woven or knitted fabrics, nonwoven fabrics, and foamed resin sheets.
Laminate.

(In the formula, _R1 and _R2 are aliphatic hydrocarbon groups having 7 to 11 carbon atoms and may be the same or different. Furthermore, n and m are positive integers. When _R1 and _R2 are different, the copolymer is a block copolymer or a random copolymer.)

(In the formula, _R3 and _R4 are aliphatic hydrocarbon groups having 3 to 6 carbon atoms and may be the same or different. Furthermore, x and y are positive integers. When _R3 and _R4 are different, the copolymer is a block copolymer or a random copolymer.)

(In the formula, _R5 is an aliphatic hydrocarbon group having 3 to 5 carbon atoms, and _R6 is an aliphatic hydrocarbon group having 8 to 12 carbon atoms. Furthermore, a and b are positive integers, and _R5 and _R6 are block copolymers or random copolymers.)

[2] The laminate described in [1] above, wherein the adhesive resin is a polyurethane resin.

[3] The peel strength when the surface layer is peeled from the laminate is 7 N/cm or more and 16 N/cm or less,
The failure mode at the time of peeling is
cohesive failure of the adhesive resin,
a material failure in the backing layer;
Interfacial failure or mixed interfacial/cohesive failure between the adhesive resin and the backing layer;
The laminate according to [1] or [2], wherein

[4] The laminate described in any one of [1] to [3] above, wherein the nap coverage of the surface layer is 70% or more and 100% or less.

[5] The laminate described in any one of [1] to [4] above, having a resin layer on at least a portion of the surface of the skin layer.

[6] The laminate described in any one of [1] to [5] above, wherein the dye content of the surface layer is 3% by mass or less.

[7] A method for producing the laminate according to any one of [1] to [6],
A method for manufacturing a laminate, comprising the steps of applying an adhesive to one surface of sheet A which will become the backing layer, placing sheet B which will become the skin layer on the surface coated with the adhesive, and curing the adhesive to integrate sheet A and sheet B via an adhesive resin which is the cured product of the adhesive.

[8] The method for manufacturing a laminate described in [7] above, wherein the adhesive is a two-component polyurethane adhesive composed of an isocyanate compound and a polyol compound.

[9] An interior material comprising the laminate described in any one of [1] to [6].

[10] A vehicle part comprising the laminate described in any one of [1] to [6].

[11] Furniture comprising the laminate described in any one of [1] to [6].

According to the present invention, it is possible to obtain a laminate that can maintain the color development and friction resistance of the surface layer even after high-temperature press molding, while also achieving sufficient peel strength, as well as interior materials, vehicle parts, and furniture that include the laminate.

FIG. 1 is a cross-sectional conceptual diagram illustrating and explaining one embodiment of the laminate according to the present invention, in which a surface layer and a backing layer are laminated together via an adhesive resin. FIG. 2 is a conceptual perspective view illustrating and explaining the method for evaluating the surface quality of a laminate according to the present invention.

The laminate of the present invention is a laminate in which a surface layer containing artificial leather and a backing layer are laminated via an adhesive resin, the artificial leather comprising a fiber structure and a polycarbonate-based polyurethane, the fiber structure comprising ultrafine fibers made of a polyester-based resin containing a black pigment and/or a chromatic pigment, and the polycarbonate-based polyurethane comprising:
It has a skeleton represented by the following general formula (1) and a skeleton represented by the following general formula (2), or
It has a skeleton represented by general formula (2) and a skeleton represented by general formula (3),
The backing layer is at least one material selected from the group consisting of woven or knitted fabrics, nonwoven fabrics, and foamed resin sheets.

(In the formula, _R1 and _R2 are aliphatic hydrocarbon groups having 7 to 11 carbon atoms and may be the same or different. Furthermore, n and m are positive integers. When _R1 and _R2 are different, the copolymer is a block copolymer or a random copolymer.)

(In the formula, _R3 and _R4 are aliphatic hydrocarbon groups having 3 to 6 carbon atoms and may be the same or different. Furthermore, x and y are positive integers. When _R3 and _R4 are different, the copolymer is a block copolymer or a random copolymer.)

(In the formula, _R5 is an aliphatic hydrocarbon group having 3 to 5 carbon atoms, and _R6 is an aliphatic hydrocarbon group having 8 to 12 carbon atoms. Furthermore, a and b are positive integers, and _R5 and _R6 are block copolymers or random copolymers.)
These components will be described in detail below, but the present invention is not limited to the scope of the following description as long as it does not deviate from the gist of the invention.

[Fiber structure]
First, the fiber structure according to one embodiment of the present invention (hereinafter also referred to as "this embodiment") is composed of ultrafine fibers made of polyester resin containing a black pigment and/or a chromatic pigment.

(1) Polyester Resin First, the ultrafine fibers in this embodiment are made of polyester resin.

Examples of the polyester resins include polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, polyethylene-1,2-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylate, polylactic acid, and mixtures and copolymers thereof. Among these, polyethylene terephthalate, which is the most commonly used, or polyester copolymers containing primarily ethylene terephthalate units are preferably used.

In this invention, "mainly" means that of the components contained, the component that is the most abundant by mass. When the component is composed of equal parts, such as 50:50, both components are considered to be the main components.

Furthermore, the polyester resin may be a single polyester or two or more different polyesters. However, when two or more different polyesters are used, from the viewpoint of compatibility between the two or more components, the difference in intrinsic viscosity (IV value) of the polyesters used is preferably 0.50 or less, and more preferably 0.30 or less.

In the present invention, the intrinsic viscosity is calculated by the following method.
(i) Dissolve 0.8 g of a sample polymer in 10 mL of orthochlorophenol.
(ii) Using an Ostwald viscometer at a temperature of 25°C, calculate the relative viscosity _ηr using the following formula and round off to two decimal places.
η _r =η/η ₀ =(t×d)/(t ₀ ×d ₀ ) (formula).
Intrinsic viscosity (IV value)=0.0242η _r +0.2634 (formula).
(Here, η represents the viscosity of the polymer solution, η ₀ represents the viscosity of orthochlorophenol, t represents the solution's falling time (seconds), d represents the solution's density (g/cm ³ ), t ₀ represents the orthochlorophenol's falling time (seconds), and d ₀ represents the orthochlorophenol's density (g/cm ³ ).)

Furthermore, the polyester-based resin used in this embodiment may contain inorganic particles such as titanium oxide particles, lubricants, heat stabilizers, ultraviolet absorbers, conductive agents, heat storage agents, antibacterial agents, etc., as needed, within the scope of not interfering with the objectives of the present invention.

(2) Black Pigment and Chromatic Pigment Next, the polyester-based resin in this embodiment contains a black pigment and/or a chromatic pigment. Here, in the present invention, a "chromatic pigment" refers to a pigment of a color such as red, blue, green, or yellow, and specifically refers to a pigment of a color having a chroma (C ^* ) of 10 or more in the CIE 1976 L ^* a ^* b ^* color space determined in accordance with JIS K 5101-2-2. When the polyester-based resin contains a black pigment and/or a chromatic pigment (hereinafter, black pigment, chromatic pigment, and mixtures of black pigment and chromatic pigment may be collectively referred to simply as "pigment"), a laminate having a surface layer that is resistant to discoloration even when exposed to heat during press molding is obtained.

Preferred examples of black pigments include carbon-based black pigments such as carbon black and graphite, and oxide-based black pigments such as triiron tetroxide and copper-chromium composite oxide. In particular, carbon black is more preferred as the black pigment, as it is easier to obtain fine particle sizes and has excellent dispersibility within ultrafine fibers.

Furthermore, as the chromatic pigment, a pigment close to the target color can be used, and preferred examples include iron oxyhydroxide (e.g., "TM Yellow 8170" manufactured by Dainichiseika Chemicals Co., Ltd.), iron oxide (e.g., "TM Red 8270" manufactured by Dainichiseika Chemicals Co., Ltd.), and cobalt aluminate (e.g., "TM Blue 3490E" manufactured by Dainichiseika Chemicals Co., Ltd.). Here, white pigments that are not "chromatic," such as zinc oxide and titanium oxide, are not included in the chromatic pigments referred to in this invention.

Furthermore, the average particle diameter of the pigment in the ultrafine fibers is preferably 0.05 μm or more and 0.20 μm or less. Here, the average particle diameter of the pigment in this embodiment refers to the particle diameter when present in the ultrafine fibers, and is what is generally called the secondary particle diameter, measured by the method described below. By setting the lower limit of the average particle diameter of the pigment to preferably 0.05 μm or more, and more preferably 0.07 μm or more, the pigment is better held within the ultrafine fibers, further suppressing detachment of the pigment due to heat during press molding, resulting in a laminate with a surface layer that is even more resistant to discoloration. On the other hand, by setting the upper limit of the average particle diameter of the pigment to preferably 0.20 μm or less, more preferably 0.18 μm or less, and even more preferably 0.16 μm or less, the ultrafine fibers that make up the artificial leather surface layer have even greater strength, resulting in a laminate that exhibits high abrasion resistance.

The coefficient of variation (CV) of the particle size of the pigment in the ultrafine fibers is preferably 75% or less. If this coefficient of variation (CV) of particle size is preferably 75% or less, more preferably 50% or less, and even more preferably 35% or less, the particle size distribution will be narrow, and spinning defects and significant decreases in yarn strength due to small particles falling off the surface or significant agglomeration of particles will be further suppressed. Note that there is no particular lower limit on the coefficient of variation in this embodiment, but from the perspective of operability when spinning the ultrafine fibers, it is desirable for it to be 0.1% or more.

In the present invention, the average particle size and the coefficient of variation of particle size of the pigment are values measured and calculated by the following methods.
(i) A laminate or a single skin layer before lamination is obtained, and a test piece of 10 mm or more square is randomly taken from the sample. Ultrathin sections of 5 μm to 10 μm thick are prepared so that the longitudinal cross section of the test piece (a cross section through which the skin layer and backing layer can be observed if the test piece is a laminate) can be observed.
(ii) The cross section of the laminate in the ultrathin slice is observed at 10,000 magnifications using a transmission electron microscope (TEM, for example, "H7700" manufactured by Hitachi High-Technologies Corporation).
(iii) In the cross section of the test piece, photograph the ultrafine fibers of the artificial leather contained in the skin layer, which are circular or elliptical in shape and appear to have a single fiber diameter of 15.0 μm or less.
(iv) Using image analysis software (for example, "VW-9000" manufactured by Keyence Corporation), measure the circle-equivalent particle diameter of 20 pigment particles contained within a 2.3 μm × 2.3 μm field of view of the observed image. If there are fewer than 20 pigment particles contained within the 2.3 μm × 2.3 μm field of view, select another fiber that can measure 20 particles and measure it.
(v) Calculate the average value (arithmetic mean) and coefficient of variation (CV) for the particle diameters measured at 20 points. In the present invention, the coefficient of variation is calculated using the following formula, and is rounded down to an integer.
Coefficient of variation of particle size (%)=(standard deviation of particle size)/(arithmetic mean of particle size)×100 (formula).

When measuring a fiber structure containing ultrafine fibers, prepare an ultrathin section of the fiber structure with a thickness of 5 μm to 10 μm, and then perform the measurements from (ii) onwards.

The pigment content in the ultrafine fibers is preferably 0.5% by mass or more and 2.0% by mass or less, relative to the mass of the ultrafine fibers. By setting the lower limit of the pigment content to preferably 0.5% by mass or more, more preferably 0.7% by mass or more, and even more preferably 0.9% by mass or more, the amount of dye required to achieve the desired color development in dyeing the artificial leather surface layer can be further reduced, thereby reducing the amount of dye contained in the artificial leather. This reduces the risk of dye bleeding due to heat during press molding, resulting in a laminate that exhibits high friction fastness. On the other hand, by setting the upper limit of the pigment content to preferably 2.0% by mass or less, more preferably 1.8% by mass or less, and even more preferably 1.6% by mass or less, the physical properties of the artificial leather surface layer, such as strength and elongation, are further improved, resulting in a laminate that exhibits even higher friction fastness.

In the present invention, the pigment content is a value measured and calculated by the following method.
(i) When measuring from a laminate, carefully peel off the surface layer and remove the backing layer and any layers other than the artificial leather of the surface layer. If the surface layer is obtained before lamination, remove any layers other than the artificial leather of the surface layer. If the artificial leather is obtained alone, evaluation can be performed from (ii) without performing the above-mentioned removal work.
(ii) A piece of artificial leather approximately 8 to 20 cm square is immersed in N,N-dimethylformamide (DMF) and boiled for 2 hours or more to dissolve only the polyurethane, and the remaining ultrafine fibers are collected and their mass is measured. This is the mass (g) of the ultrafine fibers before dissolution.
(iii) The polyester resin in the collected ultrafine fibers is dissolved using a mixture of phenol and tetrachloroethane, the pigment is extracted, and the resulting mixture is filtered using a filter with a mesh size of 0.45 μm or an equivalent. The mass of the residue remaining on the filter is measured. This is the mass (g) of the residue on the filter.
(iv) The residue obtained in (iii) is subjected to elemental analysis, and the ratio of the black pigment to the chromatic pigment is calculated.
(v) The proportion (mass%) of pigment contained in ultrafine fibers is calculated using the following formula, and the obtained value is rounded off to one decimal place.
(mass (g) of residue on filter × ratio of black pigment to chromatic pigment)/(mass (g) of ultrafine fibers before dissolution) × 100 (formula).

In addition, if the content can be calculated from the manufacturing process, it can also be calculated using that method.

(3) Ultrafine Fibers The ultrafine fibers in this embodiment are made of the polyester resin containing the pigment. Here, in the present invention, the ultrafine fibers refer to fibers having a single fiber diameter of 15.0 μm or less.

The average single fiber diameter of the ultrafine fibers is preferably 0.1 μm or more and 10.0 μm or less. By setting the lower limit of the average single fiber diameter of the ultrafine fibers to preferably 0.1 μm or more, and more preferably 0.5 μm or more, the ultrafine fibers of the artificial leather in the skin layer will have even greater strength, resulting in a laminate with even greater abrasion resistance, and a laminate that is free of cracks or tears in the skin layer even when partially stretched by press molding. On the other hand, by setting the upper limit of the average single fiber diameter of the ultrafine fibers to preferably 10.0 μm or less, more preferably 6.0 μm or less, and even more preferably 4.5 μm or less, not only will the artificial leather have an even denser, softer surface quality, but also a flexible skin that can easily conform to the molding die, even when partially stretched by press molding.

In the present invention, the average single fiber diameter of the ultrafine fibers is a value measured and calculated by the following method.
(i) A laminate or a single skin layer before lamination is obtained, and test pieces of 10 mm square or larger are randomly taken. Ultrathin sections of 5 μm to 10 μm thick are prepared so that the longitudinal cross section of the test piece (in the case of a laminate, a cross section in which the cross sections of the skin layer and backing layer can be observed) can be observed.
(ii) A photograph of the cross section of the laminate in the ultrathin slice is taken at 1000x magnification using a scanning electron microscope (SEM, for example, "VHX-D500/D510" manufactured by Keyence Corporation).
(iii) In the cross section of the test piece in the ultrathin section, fibers in the epidermis layer that are circular or elliptical and close to circular, and that appear to have a single fiber diameter of 15.0 μm or less, are considered to be ultrafine fibers, and 10 such ultrafine fibers are randomly selected, and the single fiber diameter of each is measured.
(iv) Calculate the arithmetic mean value of the 10 single fiber diameters and round to the nearest tenth.

Furthermore, a round cross-sectional shape is preferable for the ultrafine fibers, as this not only facilitates stable formation of the ultrafine fibers during the manufacturing process and results in an artificial leather with an excellent balance of quality, texture, and strength, but also results in a laminate that is flexible and more easily conforms to the molding die when partially stretched during press molding, and does not suffer from cracks or tears in the skin layer. However, cross-sectional shapes such as oval, triangle, and other polygonal (including those with rounded corners), sector, cross, hollow, Y-shape, T-shape, and U-shape can also be used. In this case, the average single fiber diameter of ultrafine fibers is determined by first measuring the cross-sectional area of a single fiber and then calculating the diameter when the cross-section is considered to be circular. Furthermore, in the above measurement method, the phrase "circular or elliptical, close to circular" should be read as "having the original cross-sectional shape of the ultrafine fiber being measured, or a shape close to circular."

(4) Fiber Structure The fiber structure in this embodiment includes the ultrafine fibers. Examples of the form of the fiber structure include nonwoven fabric, woven/knitted fabric, and those containing both. These can be used appropriately depending on the properties required for each application or purpose. Among these, it is preferable that the fiber structure is a substrate primarily made of nonwoven fabric (a fiber sheet in which 60% by mass or more of the fiber structure is nonwoven fabric), and it is more preferable that the fiber structure is nonwoven fabric (100% by mass of the fiber structure is nonwoven fabric). By using a fiber structure as a substrate primarily made of nonwoven fabric, a uniform and elegant appearance and texture can be obtained when the surface is raised. On the other hand, it is also preferable that the fiber structure is a fiber sheet in which a woven/knitted fabric is entangled and integrated with a nonwoven fabric, which results in a laminate with higher strength. In the present invention, woven/knitted fabric is a general term for woven fabrics and knitted fabrics.

Nonwoven fabrics come in two forms: long-fiber nonwoven fabrics, which are primarily composed of filaments, and short-fiber nonwoven fabrics, which are primarily composed of fibers 100 mm or less. Long-fiber nonwoven fabrics are preferred because they produce a skin layer with excellent strength. On the other hand, short-fiber nonwoven fabrics allow for more fibers to be oriented in the thickness direction of the skin layer than long-fiber nonwoven fabrics, and can give the surface of the skin layer a high degree of density when raised.

When using a short-fiber nonwoven fabric, the average fiber length of the ultrafine fibers is preferably 25 mm or more and 90 mm or less. By setting the average fiber length to 90 mm or less, more preferably 80 mm or less, and even more preferably 70 mm or less, good quality and texture can be achieved. On the other hand, by setting the average fiber length to 25 mm or more, more preferably 35 mm or more, and even more preferably 40 mm or more, a laminate with excellent abrasion resistance can be obtained.

In the present invention, the average fiber length of the ultrafine fibers is measured and calculated by the following method. When the average fiber length can be determined from the manufacturing process, it can also be calculated by that method.
(i) When measuring from a laminate, carefully peel off the surface layer and remove the backing layer and any layers other than the artificial leather of the surface layer. If the surface layer is obtained before lamination, remove any layers other than the artificial leather of the surface layer. If the artificial leather is obtained alone, evaluation can be performed from (ii) without performing the above-mentioned removal work.
(ii) The artificial leather is immersed in N,N-dimethylformamide (DMF) and boiled for 2 hours or more to dissolve only the polyurethane, and the remaining ultrafine fibers are collected.
(iii) A photograph of the collected ultrafine fibers is taken at 20 to 50 magnifications using a scanning electron microscope (SEM, for example, "VHX-D500/D510" manufactured by Keyence Corporation).
(iv) Ten fibers are randomly selected from the collected ultrafine fibers, and the fiber length of each is measured.
(v) Calculate the arithmetic average of the lengths of the 10 fibers and round down to an integer.

[Polycarbonate-based polyurethane]
The artificial leather included in the laminate of this embodiment contains, in addition to the fiber structure, a polycarbonate-based polyurethane having a skeleton represented by the following general formula (1) and a skeleton represented by the following general formula (2), or a skeleton represented by the following general formula (2) and a skeleton represented by the following general formula (3).

(In the formula, _R1 and _R2 are aliphatic hydrocarbon groups having 7 to 11 carbon atoms and may be the same or different. Furthermore, n and m are positive integers. When _R1 and _R2 are different, the copolymer is a block copolymer or a random copolymer.)

(In the formula, _R3 and _R4 are aliphatic hydrocarbon groups having 3 to 6 carbon atoms and may be the same or different. Furthermore, x and y are positive integers. When _R3 and _R4 are different, the copolymer is a block copolymer or a random copolymer.)

(In the formula, _R5 is an aliphatic hydrocarbon group having 3 to 5 carbon atoms, and _R6 is an aliphatic hydrocarbon group having 8 to 12 carbon atoms. Furthermore, a and b are positive integers, and _R5 and _R6 are block copolymers or random copolymers.)

In other words, by having different structures, such as a polycarbonate skeleton having a long-chain aliphatic hydrocarbon group having 7 to 11 carbon atoms as shown in general formula (1) and a polycarbonate skeleton having a short-chain aliphatic hydrocarbon group having 3 to 6 carbon atoms as shown in general formula (2), or a polycarbonate skeleton having a short-chain aliphatic hydrocarbon group having 3 to 6 carbon atoms as shown in general formula (2) and a polycarbonate skeleton having a short-chain aliphatic hydrocarbon group having 3 to 5 carbon atoms and a long-chain aliphatic hydrocarbon group having 8 to 12 carbon atoms as shown in general formula (3), the polyurethane is more likely to have an amorphous structure, which increases its affinity with the adhesive resin when bonded to the backing layer using the adhesive resin, resulting in high peel strength between the surface layer and the backing layer. Furthermore, when an adhesive for polyurethane resin is used as the adhesive, the affinity when bonding the surface layer and backing layer is even better, and the crosslinking reaction caused by the adhesive proceeds at the interface with the polycarbonate-based polyurethane, involving the polycarbonate-based polyurethane, resulting in even higher peel strength between the surface layer and backing layer.

Furthermore, _R1 and _R2 shown in the general formula (1) and _R3 and _R4 shown in the general formula (2) may each be the same aliphatic hydrocarbon group, but if they are different aliphatic hydrocarbon groups as in the general formula (3), the polyurethane is more likely to have an amorphous structure, and when bonded to the backing layer with an adhesive resin, affinity with the adhesive resin is increased, and high peel strength can be obtained between the surface layer and the backing layer, which is preferable.

In the present invention, when it is unknown whether or not a polycarbonate-based polyurethane has all of the skeletons represented by general formulas (1), (2), and (3), and the structure needs to be confirmed, the following method can be used for evaluation.
(i) Three test pieces measuring 10 cm x 10 cm are randomly taken from the sample.
(ii) If the above sample is a laminate, carefully peel off the surface layer from the test piece, and remove the backing layer and any layers other than the artificial leather of the surface layer, leaving only the artificial leather layer of the surface layer. In the case of the surface layer before the sample is laminated, remove any layers other than the artificial leather of the surface layer. If the sample is artificial leather alone, start evaluation from (iii). In the case of a fiber structure to which a polycarbonate-based polyurethane has been applied before the sample is laminated, start evaluation from (iv).
(iii) 30% of the thickness of the artificial leather layer is removed from both surfaces, excluding the napped portion, by polishing or the like, leaving only the central 40%.
(iv) The test piece obtained in (iii) (only the central 40% portion in the thickness direction) is immersed in DMF and boiled for 2 hours or more to dissolve the polyurethane, and the solution is subjected to ¹ H-NMR measurement.

More specifically, such polyurethanes are preferably obtained by reacting polycarbonate diol A, which has a polycarbonate skeleton and hydroxyl groups at both ends of the molecular chain as shown in the general formula (1) above, with polycarbonate diol B, which has a polycarbonate skeleton and hydroxyl groups at both ends of the molecular chain as shown in the general formula (2) above, with an organic diisocyanate and a chain extender. Alternatively, polyurethanes are preferably obtained by reacting polycarbonate diol B, polycarbonate diol C, which has a polycarbonate skeleton and hydroxyl groups at both ends of the molecular chain as shown in the general formula (3) above, with an organic diisocyanate and a chain extender. These polycarbonate diols can be produced by the transesterification reaction of alkylene glycol with a carbonate ester, or by the reaction of phosgene or a chloroformate ester with an alkylene glycol, for example.

Here, the alkylene glycol used to obtain polycarbonate diol A having a polycarbonate skeleton with a long-chain aliphatic hydrocarbon group having 7 to 11 carbon atoms, as represented by the general formula (1), can be straight-chain alkylene glycols such as 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol, or branched alkylene glycols such as 2-methyl-1,8-octanediol, 2,7-dimethyl-1,8-octanediol, and 2,8-dimethyl-1,9-nonanediol. Copolymerized polycarbonate diols obtained from straight-chain alkylene glycols such as those obtained from 1,9-nonanediol and 2-methyl-1,8-octanediol and branched alkylene glycols are particularly preferred, as they have a high affinity with adhesive resins when bonded to a backing layer using the adhesive resin, thereby achieving high peel strength between the surface layer and the backing layer. Furthermore, when an adhesive for polyurethane resin is used as the adhesive, the affinity when bonding the surface layer and backing layer is even better, and the crosslinking reaction caused by the adhesive proceeds at the interface with the polycarbonate-based polyurethane, involving the polycarbonate-based polyurethane, resulting in even higher peel strength between the surface layer and backing layer.

The alkylene glycol used to obtain polycarbonate diol B having a polycarbonate skeleton with a short-chain aliphatic hydrocarbon group having 3 to 6 carbon atoms, as represented by the general formula (2), can be straight-chain alkylene glycols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, or 1,6-hexanediol, or branched alkylene glycols such as propylene glycol, neopentyl glycol, or 3-methyl-1,5-pentanediol. Copolymerized polycarbonate diols obtained from straight-chain alkylene glycols obtained from 1,6-hexanediol and 3-methyl-1,5-pentanediol, etc., and branched alkylene glycols, are particularly preferred, as they have a high affinity with adhesive resins when bonded to a backing layer using the adhesive resin. Furthermore, when an adhesive for polyurethane resin is used as the adhesive, the affinity when bonding the surface layer and backing layer is even better, and the crosslinking reaction caused by the adhesive proceeds at the interface with the polycarbonate-based polyurethane, involving the polycarbonate-based polyurethane, resulting in even higher peel strength between the surface layer and backing layer.

On the other hand, as the alkylene glycol for obtaining polycarbonate diol C having a short-chain aliphatic hydrocarbon group with 3 to 5 carbon atoms and a long-chain aliphatic hydrocarbon group with 8 to 12 carbon atoms, which is represented by the general formula (3), alkylene glycols having 3 to 5 carbon atoms (a1) include alkylene glycols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,3-propanediol, and 1,3-butanediol. Examples of the alkylene glycol (a2) having 8 to 12 carbon atoms include linear alkylene glycols such as 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol, and branched alkylene glycols such as 5-methyl-2,4-heptanediol, 2-methyl-1,7-heptanediol, and 2-methyl-1,8-octanediol. When the alkylene glycol (a1) has 2 or fewer carbon atoms, it may be difficult to handle, and when it has 6 or more carbon atoms, durability and mechanical strength are impaired. When the alkylene glycol (a2) has 7 or fewer carbon atoms, the crystallinity of the copolymeric polycarbonate diol C becomes high, resulting in a hard texture, and when it has 13 or more carbon atoms, the crystallinity of the copolymeric polycarbonate diol C becomes too low, resulting in impaired durability and abrasion resistance. Among these, copolymerized polycarbonate polyurethanes that combine aliphatic hydrocarbon groups with a relatively large difference in carbon number are preferred because they tend to form an amorphous structure, which allows for more active molecular movement and therefore achieves high peel strength between the surface layer and backing layer. Copolymerized polycarbonate diols obtained from 1,4-butanediol and 1,10-decanediol are particularly preferred. These have high affinity with the adhesive resin when bonding to the backing layer. Furthermore, when an adhesive for forming a polyurethane resin is used as the adhesive, the affinity is even better when bonding the surface layer and backing layer together, and the crosslinking reaction originating from the adhesive proceeds at the interface with the polycarbonate polyurethane, involving the polycarbonate polyurethane, resulting in even higher peel strength between the surface layer and backing layer.

Furthermore, examples of carbonate esters used in transesterification reactions include diethyl carbonate and diphenyl carbonate.

The number average molecular weight (Mn) of polycarbonate diols A, B, and C is preferably 500 or more and 3000 or less, and more preferably 1500 or more and 2500 or less. A number average molecular weight of 500 or more results in a laminate with a surface layer that has a softer feel. On the other hand, a number average molecular weight of 3000 or less results in a polyurethane with higher strength, resulting in a laminate with a surface layer that has excellent abrasion resistance.

The aliphatic hydrocarbon groups of the alkylene glycols in the polycarbonate diols A and B, i.e., _R1 and _R2 , or _R3 and _R4 , may be the same or different, but it is more preferable to use a copolymer of two types of alkylene glycols, which makes the polyurethane more likely to have an amorphous structure, and when bonding to the backing layer with an adhesive, the affinity with the adhesive (adhesive resin) is higher, and high peel strength can be obtained between the surface layer and the backing layer. Furthermore, when an adhesive for forming a polyurethane-based resin is used as the adhesive, the affinity when bonding the surface layer and the backing layer is even better, and further, the crosslinking reaction derived from the adhesive proceeds at the interface with the polycarbonate-based polyurethane, involving the polycarbonate-based polyurethane, thereby obtaining even higher peel strength between the surface layer and the backing layer.

The number average molecular weight of the polycarbonate diol shown here can be determined from the hydroxyl value measured in accordance with the method specified in JIS K 0070-1992 (potentiometric titration method). The composition ratio of the alkylene glycols that make up the polycarbonate diol can be determined by gas chromatography (e.g., Shimadzu GC-14B, J&W DB-WAX column) using diethylene glycol diethyl ester as the internal standard and an FID detector.

The organic diisocyanates mentioned above include, for example, aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate, isophorone diisocyanate, and xylylene diisocyanate, and aromatic diisocyanates such as diphenylmethane-4,4'-diisocyanate (MDI) and tolylene diisocyanate, and these can also be used in combination. Among these, HDI and MDI are preferred from the standpoint of light resistance.

The chain extenders mentioned above can preferably be amine-based chain extenders such as ethylenediamine or methylenebisaniline, or diol-based chain extenders such as ethylene glycol. Polyamines obtained by reacting polyisocyanate with water can also be used as chain extenders. Among these, ethylene glycol is preferred from the standpoint of operability.

The polycarbonate polyurethane can also contain various additives depending on the purpose, such as phosphorus-based, halogen-based, and inorganic flame retardants; phenol-based, sulfur-based, and phosphorus-based antioxidants; benzotriazole-based, triazine-based, benzophenone-based, salicylate-based, cyanoacrylate-based, and oxalic acid anilide-based ultraviolet absorbers; hindered amine-based and benzoate-based light stabilizers; hydrolysis-resistant stabilizers such as polycarbodiimides; plasticizers; antistatic agents; surfactants; coagulation adjusters; and dyes. The aforementioned pigments may also be included.

Generally, the polyurethane content in artificial leather is adjusted appropriately taking into consideration the type of polyurethane used, the manufacturing method of the polyurethane, and the texture and physical properties. However, in this embodiment, the polycarbonate-based polyurethane content in the surface layer is preferably 10% by mass or more and 60% by mass or less. By setting the polycarbonate-based polyurethane content to preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, the bonds between the ultrafine fibers via the polycarbonate-based polyurethane can be further strengthened, further improving the abrasion resistance of the artificial leather in the surface layer. On the other hand, by setting the polycarbonate-based polyurethane content to preferably 60% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, not only will the artificial leather be more flexible, but the laminate will also be flexible enough to conform to the molding die even when partially stretched by press molding as a laminate, and will not suffer from cracks or tears in the surface layer.

In the present invention, the content of polycarbonate-based polyurethane in the artificial leather is measured and calculated by the following method.
(i) Three test pieces measuring 10 cm x 10 cm are randomly taken from the sample.
(ii) If the above sample is a laminate, carefully peel off the surface layer from the test piece, and remove the backing layer and any layers other than the artificial leather of the surface layer, leaving only the artificial leather layer of the surface layer. In the case of the surface layer before the sample is laminated, remove any layers other than the artificial leather of the surface layer. If the sample is artificial leather alone, start evaluation from (iii). In the case of a fiber structure to which a polycarbonate-based polyurethane has been applied before the sample is laminated, start evaluation from (iv).
(iii) 30% of the thickness of the artificial leather layer is removed from both surfaces, excluding the napped portion, by polishing or the like, leaving only the central 40%.
(iv) The test piece obtained in (iii) (only the central 40% portion in the thickness direction) is immersed in DMF to dissolve the polyurethane. The test piece remaining after dissolution is dried at 25°C for 24 hours. The mass ratio of the test piece before and after dissolution is calculated using the following formula, and the arithmetic average (%) of the three test pieces is rounded to one decimal place to calculate the polyurethane content.
(mass of test piece before dissolution (g)−mass of test piece after dissolution and drying (g))/(mass of test piece before dissolution (g))×100 (formula).

The number average molecular weight of polycarbonate-based polyurethane can be determined by evaluating a 0.125 wt% N,N-dimethylformamide solution using gel permeation chromatography (e.g., Tosoh Corporation's HLC-8220GPC, Tosoh Corporation's Guard column α, TSKgel α-M column).

Although it is not possible to obtain an independent value for the composition ratio of the two types of alkylene glycol residues from polycarbonate-based polyurethane, an estimated value for the ratio of the two types of alkylene glycol units can be calculated from the compound structure and number-average molecular weight.

[Artificial leather]
The surface layer of the laminate of this embodiment includes artificial leather containing the fiber-entangled body and the polyurethane.

In this artificial leather, it is preferable that the surface opposite the backing layer of the artificial leather, the side that does not come into contact with the adhesive resin, has a napped portion with sufficient length and directional flexibility to leave a mark when the user runs a finger over it, i.e., a so-called finger mark, by changing the direction of the nap.

More specifically, the nap length in the napped portion is preferably 200 μm or more and 1000 μm or less, and more preferably 250 μm or more and 800 μm or less. By setting the nap length to 200 μm or more, the surface nap covers the polyurethane, further suppressing exposure of the polyurethane to the surface of the artificial leather and resulting in a laminate with more uniform color development. Furthermore, when the fiber structure constituting the artificial leather is a fiber sheet in which a woven fabric is entangled and integrated with a nonwoven fabric, setting the nap length of the surface napped portion within the above range is preferable because it can adequately cover the fibers of the woven fabric located near the surface of the artificial leather in the skin layer. On the other hand, setting the nap length to 800 μm or less is preferable because it can result in a laminate with excellent design effects and abrasion resistance.

In the present invention, the nap length of the napped portion on the surface of the artificial leather is calculated by the following method.
(i) When measuring from a laminate, carefully peel off the surface layer and remove the backing layer and any layers other than the artificial leather of the surface layer. If the surface layer is obtained before lamination, remove any layers other than the artificial leather of the surface layer. If the artificial leather is obtained alone, evaluation can be performed from (ii) without performing the above-mentioned removal work.
(ii) With the nap of the raised portion of the surface of the artificial leather of the skin layer raised using a lint brush or the like, a thin slice 1 mm thick is prepared in the cross-sectional direction of a surface perpendicular to the longitudinal direction of the artificial leather using a razor blade or the like.
(iii) The cross section of the napped portion on the surface of the artificial leather is observed at 90x magnification using an SEM (for example, "VHX-D500/D510" manufactured by Keyence Corporation).
(iv) In the SEM image taken, the height of the layer consisting only of ultrafine fibers is measured at 10 points at intervals of 200 μm in the width direction of the cross section of the napped portion on the surface of the artificial leather.
(v) The average value (arithmetic mean) of the heights of the layers consisting only of ultrafine fibers measured at 10 points is calculated and rounded down to an integer.

Of course, to further improve adhesion to the backing layer, it is also preferable to have a napped portion on the surface of the backing layer that comes into contact with the adhesive resin. In this case, it is preferable that the nap coverage rate of the napped portion on the backing layer side be 98% or more.

[Laminate]
The laminate of this embodiment is a laminate formed by laminating a surface layer and a backing layer via an adhesive resin. Here, the "laminate" has a certain area and is not limited to a plate-like, three-dimensional, or other shape, but is preferably a shape that can be press-molded, and a sheet-like shape is particularly preferred. The components of the laminate will be described in order.

(1) Skin Layer The skin layer used in the laminate of the present embodiment includes the above-described artificial leather.

The skin layer used in the laminate of this embodiment preferably has a resin layer on at least a portion of the surface, as this improves the surface design.

In the skin layer used in the laminate of this embodiment, the area of the surface covered by the nap (napped coverage) is preferably 70% or more and 100% or less. By setting the napped coverage to 70% or more, exposure of polyurethane to the surface of the skin layer can be further suppressed even when the laminate is stretched during molding processing.

In the present invention, the nap coverage of the epidermal layer is measured and calculated by the following method.
(i) When the artificial leather of the skin layer has a napped portion on its surface, the napped portion on the surface is laid down using a lint brush or the like, and an observation image is taken using an SEM (for example, "VHX-D500/D510" manufactured by Keyence Corporation) at a magnification of 30 to 90 times to observe the surface of the laminate so that the presence of the nap can be seen.
(ii) Using image analysis software (having the function of calculating the area ratio of a specified pixel, for example, "ImageJ" from the US National Institutes of Health (NIH)), the ratio of the total area (mm ² ) of the napped portion to the total actual area of 9 mm ² was calculated, and this was taken as the napped coverage rate. The total area ratio can be calculated by using image analysis software on the captured SEM image to correct the image so that the pixel value of the brightest part (white part) of the SEM image is 255 and the pixel value of the darkest part (black part) of the SEM image is 0 to obtain a grayscale image, setting 128 as the threshold for this 256-level image, and performing binarization processing, and regarding the parts of the grayscale image where the pixel value was 128 to 255 (white part) as the napped portion. In addition, when calculating the nap-standing coverage, if a substance that is not nap-standing, such as exposed polyurethane or dust attached, is calculated as nap-standing and significantly affects the nap-standing coverage, the image is manually edited and the color tone of the non-napped substance is set to 0, and that part is calculated as a non-napped part.

The surface layer used in the laminate of this embodiment may be colored by dyeing or the like. The dye is preferably retained in the ultrafine fibers. The dye content in the surface layer after dyeing is preferably 3% by mass or less. The dye used to dye the surface layer may discolor or fade due to the heat generated during press molding, which can cause molecular chain scission and recombination. Therefore, a dye content of 2% by mass or less is more preferable, as this further reduces the effects of discoloration and fading of the surface layer due to changes in the molecular structure of the dye. In this embodiment, a dye-free embodiment is also preferred. Here, "dye-free" includes an embodiment in which a dye is not used in the design, or an embodiment in which the content measured and calculated by the method described below is below the lower limit of detection. In this specification, "dye-free" refers to a embodiment in which the content measured and calculated by the method described below is above the lower limit of detection, which is the lower limit of the content when a dye is included. Generally, the lower detection limit for the content measured and calculated using the method described below is 0.05% by mass.

The content of the dye in the surface layer used in the laminate of the present invention is calculated by the following method.
(i) When measuring from a laminate, carefully peel off the surface layer and remove the layers other than the surface layer of the backing material layer. If a surface layer alone before lamination is obtained, evaluation can be performed from (ii) without performing the above-mentioned removal work.
(ii) 5 g of the surface layer is immersed in 30 mL of dimethylformamide or the like, and refluxed at a heating temperature of 160°C for 30 minutes to obtain a solution in which the polymeric elastomer, the dye, and the resin of the resin layer contained in the surface layer, which is an optional component, are dissolved.
(iii) The solution is reprecipitated in 200 mL of methanol, and separated into methanol solution A in which the dye is dissolved and a coagulated polymeric elastomer.
(iv) The coagulated elastomer is dissolved in 20 mL of dimethylformamide or the like, and reprecipitated with 200 mL of methanol to obtain a methanol solution B in which the dye is dissolved.
(v) Methanol solutions A and B are mixed, and the solid matter is removed using a filter with a mesh size of 0.45 μm or an equivalent. After that, the methanol is distilled under reduced pressure, and the residue is used as the dye and its mass is measured.
(vi) Calculate the dye content in the epidermal layer using the following formula and round off to the first decimal place.
Dye content (mass %)=((dye mass)/(skin layer mass))×100 (formula).

In the laminate of this embodiment, the thickness of the skin layer is preferably 0.3 mm or more and 1.5 mm or less. A skin layer thickness of preferably 0.3 mm or more, more preferably 0.4 mm or more, and even more preferably 0.5 mm or more results in a laminate with better surface quality, in which the adhesive resin is less visible from the surface. On the other hand, a skin layer thickness of preferably 1.5 mm or less, more preferably 1.4 mm or less, and even more preferably 1.3 mm or less results in a flexible skin that easily conforms to the molding die, even when partially stretched by press molding, resulting in a laminate with excellent formability.

The thickness of the skin layer is measured and calculated by the following method.
(i) A laminate or a single skin layer before lamination is obtained, and if the sample has nap, a lint brush or the like is used to lay down the nap of the napped portion on the surface of the skin layer, and a thin section having a thickness of 1 mm is prepared in the cross-sectional direction of a surface perpendicular to the longitudinal direction of the laminate.
(ii) The cross section of the surface layer of the laminate is observed at 90x magnification using an SEM (for example, "VHX-D500/D510" manufactured by Keyence Corporation).
(iii) In the SEM image, the length from the adhesive resin to the surface is measured at 10 points at 200 μm intervals in the width direction of the cross section of the skin layer. Here, the "length from the adhesive resin to the surface" means the length of a perpendicular line (not shown) from the boundary (20) between the adhesive resin (14) and the skin layer side shown in FIG. 1 to the outermost layer.
(iv) Calculate the average (arithmetic mean) of the lengths (mm) measured at the 10 points and round off to the first decimal place.

Note that Figure 1 above is a cross-sectional conceptual diagram illustrating and explaining one embodiment of the laminate of the present invention, in which a surface layer and a backing layer are laminated via an adhesive resin. The laminate (11) is formed by laminating a backing layer (13), a fiber structure including ultrafine fiber bundles (12c) composed of ultrafine fibers (12a), and artificial leather including polycarbonate-based polyurethane (12b) via an adhesive resin (14).

When a resin layer is present on at least a portion of the surface of the skin layer, the area ratio of the resin portion to the fabric surface is preferably 10% or more. This area ratio is preferably 10% or more, more preferably 15% or more, and even more preferably 20% or more, resulting in a laminate with even better abrasion resistance. On the other hand, the upper limit of this area ratio range is 100%, meaning that the entire surface of the skin layer has a resin layer. Therefore, it is preferable that the area ratio of the resin portion to the fabric surface be 10% or more and 100% or less.

In the present invention, the area ratio of the resin portion of the skin layer is measured and calculated by the following method.
(i) When the artificial leather of the skin layer has a napped portion on a part of its surface, the napped portion on the surface is laid down using a lint brush or the like, and an observation image is taken using an SEM (for example, "VHX-D500/D510" manufactured by Keyence Corporation) at a magnification of 30 to 90 times to observe the surface of the laminate so that the presence of the nap can be seen.
(ii) Using image analysis software (such as "ImageJ" from the National Institutes of Health (NIH)) with the function of calculating the area ratio of a specified pixel, the ratio of the total area ( ^mm2 ) of the resin portion to the total actual area of 9 ^mm2 is calculated, and this is taken as the area ratio of the resin portion of the skin layer. The total area ratio can be calculated by using image analysis software on the captured SEM image to correct the image so that the pixel value of the brightest part (white part) of the SEM image is 255 and the pixel value of the darkest part (black part) of the SEM image is 0 to obtain a grayscale image, and then binarizing this 256-level image by setting 128 as the threshold, and deeming the parts of the grayscale image with pixel values of 0 to 127 (black parts) to be the resin portion.

(2) Backing Layer The backing layer used in the laminate of this embodiment is at least one material selected from the group consisting of woven or knitted fabrics, nonwoven fabrics, and foamed resin sheets.

Examples of the woven and knitted fabrics include plain weave, twill weave, satin weave, and various woven fabrics based on these weaves; weft knitting, represented by warp knitting and tricot knitting; lace knitting; and various knitted fabrics based on these knitting structures. The polymers that make up these fabrics, i.e., the polymers that are the main components of the fibers that make up the woven and knitted fabrics (polymers that account for 60% or more by mass of the polymers that make up the fibers), include polymers such as polyester, polyamide, polyolefin, various copolymers containing these components, mixtures of these, and polymers that form natural fibers such as cotton and wool. Of these, polyester and polyamide are preferred from the standpoint of durability, particularly mechanical strength.

Examples of the nonwoven fabric include needle-punched nonwoven fabric, paper-made nonwoven fabric, spunbonded nonwoven fabric, melt-blown nonwoven fabric, spunlaced nonwoven fabric, air-through nonwoven fabric, chemically bonded nonwoven fabric, flash-spun nonwoven fabric, and combinations thereof. The polymer that makes up the nonwoven fabric, i.e., the polymer that is the main component of the fibers that make up the nonwoven fabric (polymers that account for 60% by mass of the polymers that make up the fibers), includes polymers such as polyester, polyamide, polyolefin, various copolymers containing these components, mixtures of these, and polymers that form natural fibers such as cotton and wool. Of these, polyester and polyamide are preferred from the standpoint of durability, particularly mechanical strength.

The foamed resin sheet may be, for example, a resin with air bubbles inside that has been molded into a sheet, or a resin sheet that has been foamed by incorporating a foaming agent. Resins for foamed resin sheets include polyolefin resins, polyurethane resins, polyester resins, polyamide resins, polyphenylene sulfide resins, polycarbonate resins, polyether ketone resins, polyether imide resins, and other resins, as well as various copolymers containing these components, or mixtures of these. Among these, polyolefin resins are preferred due to their chemical resistance and resistance to dimensional changes.

Among these, it is more preferable that the backing layer be a foamed resin sheet, taking into consideration the peel strength with the skin layer, the material strength of the backing layer, the flexibility of the laminate, and the processability described below. In particular, it is preferable that the main component of the foamed resin sheet is a polyolefin resin, as this allows for a laminate that combines material strength and formability. Here, "main component" means the component that is the largest in mass among the components contained. Note that when the components are divided equally, such as 50:50, both components are considered to be main components.

The expansion ratio of the foamed resin sheet is preferably 2 to 40 times. An expansion ratio of 2 or more, more preferably 5 or more, results in a flexible laminate. On the other hand, an expansion ratio of 40 or less, more preferably 30 or less, results in a laminate with even higher peel strength and material strength. Here, the expansion ratio can be calculated from the density of the raw material of the foamed resin sheet divided by the apparent density of the foamed resin sheet.

The thickness of the backing layer in the laminate of this embodiment is preferably 0.1 mm or more and 5.0 mm or less. A backing layer thickness of preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more will result in a laminate with even better peel strength and material strength, and excellent shape retention after molding. On the other hand, a backing layer thickness of preferably 5.0 mm or less, more preferably 4.5 mm or less, and even more preferably 4.0 mm or less will result in a more flexible laminate with better moldability.

The thickness of the backing layer is measured and calculated by the following method.
(i) A thin slice having a thickness of 1 mm is prepared in the cross-sectional direction of a surface perpendicular to the longitudinal direction of the laminate.
(ii) The cross section of the backing layer of the laminate is observed at 50x magnification using a scanning electron microscope (SEM, for example, "VHX-D500/D510" manufactured by Keyence Corporation).
(iii) In the SEM image, the length from the adhesive resin to the surface of the backing layer side is measured at 10 points at 200 μm intervals in the width direction of the cross section of the backing layer. Here, "the length from the adhesive resin to the surface of the backing layer side" means the length of the perpendicular line (18) from the boundary (15) between the backing layer (13) and the adhesive resin (14) to the surface of the backing layer side, as shown in Figure 1. Note that if the adhesive has penetrated into the backing layer, the boundary is considered to be the upper end of the backing layer that is absorbed into the adhesive resin (14).
(iv) Calculate the average (arithmetic mean) of the lengths (mm) measured at the 10 points and round off to one decimal place.

(3) Adhesive Resin The adhesive resin in this embodiment can be appropriately selected from, for example, polyurethane resins, acrylic resins, silicone resins, olefin resins, polyamide resins, epoxy resins, vinyl chloride resins, polyester resins, etc., depending on the material and configuration of the backing layer. Among these, polyurethane resins or acrylic resins are preferred, considering flexibility and adhesive strength at high temperatures. Polyurethane resins, which provide high adhesive strength and flexibility, are particularly preferred. When the adhesive resin is polyurethane, it has a high affinity with the polycarbonate polyurethane of the skin layer, and urethane bonds are easily formed by the crosslinking reaction of the adhesive resin, resulting in high peel strength between the skin layer and the backing layer, which is preferable. Similarly, when the adhesive resin is acrylic resin, it is easily formed with carbonyl bonds, resulting in high peel strength between the skin layer and the backing layer, which is preferable.

As described below, the polyurethane resin can be a two-component polyurethane adhesive made from an isocyanate compound and a polyol compound.

In the laminate of this embodiment, the thickness of the adhesive resin is preferably 5 μm or more and 500 μm or less. By making the thickness of the adhesive resin preferably 5 μm or more, more preferably 75 μm or more, and even more preferably 125 μm or more, the laminate will have high formability, with wrinkles being further suppressed when the laminate is molded. Furthermore, by making the thickness of the adhesive resin preferably 500 μm or less, more preferably 400 μm or less, and even more preferably 300 μm or less, the laminate will be more flexible.

The thickness of the adhesive resin is measured and calculated by the following method.
(i) Three test pieces, each 3 cm square, are taken from any location on the laminate at equal intervals of 4 cm in the vertical direction.
(ii) The collected test piece is cut parallel to the thickness direction.
(iii) In the cross section exposed by cutting in the thickness direction, the boundary portion between the skin layer and the backing layer, which contains at least the adhesive resin, etc., is observed at 500x magnification using a scanning electron microscope (SEM, for example, "VHX-D500/D510" manufactured by Keyence Corporation).
(iv) A 500 μm × 500 μm area containing 500 or more cross-sections of ultrafine fibers is determined at the boundary and photographed. Here, the area containing 500 or more cross-sections of ultrafine fibers refers to an area at the boundary between the skin layer and the backing layer observed in (iii) above, where the number of ultrafine fibers is 500 or more and cut cross sections can be observed.
(v) Calculate the average (arithmetic mean) of the thickness (μm) of the adhesive resin present in the above-mentioned region. The thickness of the adhesive resin here means the length of the perpendicular line (16) to the boundary (15) between the backing layer and the adhesive resin and the interface of the adhesive resin on the skin layer side (area with voids of 1 μm or more), as shown in Figure 1. Note that if the adhesive has penetrated the backing layer, the interface of the adhesive resin on the backing layer side (area with voids of 1 μm or more) is considered to be the boundary (15) between the backing layer and the adhesive resin.

(4) Laminate The laminate of the present embodiment has a peel strength of 7 N/cm or more and 16 N/cm or less when the surface layer is peeled from the laminate, and a failure mode during the peeling is
cohesive failure of the adhesive resin,
a material failure in the backing layer;
Interfacial failure or mixed interfacial/cohesive failure between the adhesive resin and the backing layer;
It is preferable that either of the above is used.

By having the peel strength be preferably 7 N/cm or more, and more preferably 8 N/cm or more, the laminate is less likely to experience unintended delamination between the skin layer and the backing layer. On the other hand, by having the peel strength be preferably 16 N/cm or less, and more preferably 15 N/cm or less, the laminate is even less likely to experience unintended breakage of the skin layer. This can be achieved by using the preferred skin layer described above to create a high-strength skin layer, or by adjusting the filling depth of the adhesive resin layer.

The fact that the failure mode is the above means that neither the skin layer nor the interface between the skin layer and the adhesive resin layer will fail until the failure strength is reached, meaning that at least the skin layer itself or failure caused by the adhesive strength between the skin layer and the adhesive resin will not occur.

Here, the strength of the skin layer is the value measured in "6.3.1 Tensile strength and elongation (ISO method)" of JIS L1913:2010 "Test methods for general nonwoven fabrics," and fabrics with an average tensile strength of 200 N/5 cm or more in any two perpendicular directions are considered "high strength."

The peel strength is measured in accordance with JIS K6854-2:1999 "Test method for adhesive peel strength" and refers to the peel strength between the surface layer and the backing layer when peeled at an angle of 180°. Specifically, it is measured and calculated by the following method.
(i) A test piece measuring 150 mm length x 25 mm width is cut out from the laminate.
(ii) One end of the test piece is immersed in ethanol, immediately removed, and half of the epidermal layer is peeled off.
(iii) After sufficient drying, the test piece is placed in a tensile tester (e.g., Instron Model 3343) with the surface layer side as the "flexible adherend" and the backing layer side as the "rigid adherend," and pulled for 30 mm or more at a gripping speed of 100 mm/min, and the maximum strength is read.
(iv) The type of destruction is determined based on the following criteria:
- Peeling due to failure within the skin layer: material failure of the skin layer - Peeling due to failure within the backing layer: material failure of the backing layer - Peeling between the adhesive resin and the skin layer: interfacial failure between the adhesive resin and the skin layer - Peeling between the adhesive resin and the backing layer: interfacial failure between the adhesive resin and the backing layer - Peeling due to failure within the adhesive resin: cohesive failure of the adhesive resin - If multiple failure modes are observed, it is judged to be mixed. For example, if there is both a section where peeling occurs between the adhesive resin and the backing layer and a section where peeling occurs due to failure within the adhesive resin, it is considered to be "mixed interfacial failure/cohesive failure between the adhesive resin and the backing layer."

In the laminate of this embodiment, the adhesive resin is preferably filled into the skin layer to a depth of 5 μm or more but less than 95 μm. This filling depth is preferably 5 μm or more, more preferably 15 μm or more, and even more preferably 25 μm or more, thereby providing a laminate with excellent peel strength between the skin layer and the backing layer. On the other hand, a filling depth of less than 95 μm, more preferably 85 μm or less, and even more preferably 75 μm or less provides a laminate with excellent flexibility.
This filling depth shall be measured and calculated by the following method.
(i) Three test pieces, each 3 cm square, are taken from any location on the laminate at equal intervals of 4 cm in the vertical direction.
(ii) The collected test piece is cut parallel to the thickness direction.
(iii) In the cross section exposed by cutting in the thickness direction, the boundary portion between the skin layer and the backing layer, which contains at least the adhesive resin, etc., is observed at 500x magnification using an SEM (for example, "VHX-D500/D510" manufactured by Keyence Corporation).
(iv) A 500 μm×500 μm region including 500 or more cross-sectional portions of ultrafine fibers is defined in the boundary portion. Here, the region including 500 or more cross-sectional portions of ultrafine fibers refers to a region in the cross section observed in (iii) above, in which the number of ultrafine fibers whose cut cross sections can be observed is 500 or more.
(v) Calculate the average (arithmetic mean) of the filling depth (μm) of the adhesive resin, etc. present in the above-mentioned region. The filling depth here means the distance from the center of the ultrafine fiber (17) closest to the backing layer (13) among the ultrafine fibers whose entire outer periphery is covered with the adhesive resin, as exemplified in Figure 1, to the point where there is a gap of 1 μm or more along the direction perpendicular to the surface of the skin layer side of the laminate (11), i.e., the length of the perpendicular line (19) from the ultrafine fiber closest to the backing layer to the surface of the skin layer side.
(vi) The length of the perpendicular line (19) from the microfiber closest to the backing layer to the surface on the skin layer side is measured at 10 points, and the average value (arithmetic mean) is calculated and rounded down to an integer.

In this embodiment, the thickness of the laminate is preferably 0.4 mm or more and 7.0 mm or less. A laminate thickness of preferably 0.4 mm or more, and more preferably 0.6 mm or more, results in a laminate with superior material strength, which is less likely to tear even when partially stretched by molding or deformed into a complex shape, and which is more likely to maintain its shape after molding. On the other hand, a thickness of preferably 8.0 mm or less, and more preferably 6.5 mm or less, results in a more flexible laminate with superior moldability.

The thickness of the laminate according to the present invention is measured in accordance with "6.1.1 Method A" of "6.1 Thickness (ISO method)" of JIS L1913:2010 "Testing methods for general nonwoven fabrics," and is measured and calculated as follows.
(i) Ten test pieces, each 5 cm long and 5 cm wide, are randomly taken from the laminate.
(ii) The thickness of the test piece of (i) is measured to the nearest 0.01 mm using a thickness measuring device (for example, "Peacock Dial Thickness Gauge H" manufactured by Ozaki Seisakusho Co., Ltd.).
(iii) The arithmetic mean value (mm) of the 10 test pieces obtained in (ii) is calculated and rounded off to the first decimal place.

The basis weight of the laminate according to this embodiment is preferably 170 g/m ² or more and 1000 g/m ² or less. A basis weight of preferably 170 g/m ² or more, more preferably 200 g/m ² or more, results in a laminate with superior material strength, which is less likely to tear even when partially stretched by molding or deformed into a complex shape, and which is more likely to maintain its shape after molding. On the other hand, a basis weight of preferably 1000 g/m ² or less, more preferably 800 g/m ² or less, results in a laminate with superior moldability and greater flexibility.

The basis weight of the laminate according to the present invention is measured in accordance with "6.2 Mass per unit area (ISO method)" of JIS L1913:2010 "Testing methods for general nonwoven fabrics," and is measured and calculated as follows.
(i) Three test pieces measuring 30 cm in length and 30 cm in width are taken at random from the laminate.
(ii) The mass of the test piece of (i) is measured.
(iii) Calculate the mass per unit area of each test piece using the following formula:
Mass per unit area (g/m ² )=mass of test piece (g)/area of test piece (m ² ) (formula).
(iv) The arithmetic mean value of the mass per unit area (g/m ² ) obtained in (iii) is rounded down to an integer.

The laminate in this embodiment may have an opening. Note that "the laminate has an opening" is not limited to a portion where a hole (through opening) penetrates the laminate in the thickness direction, but also includes, for example, a case where the opening in the skin layer and the opening in the backing layer do not overlap in the surface direction and do not form a through opening. Examples of the latter include a form in which an opening is formed in advance in the skin layer and then laminated on the backing layer, or a form in which an opening is formed in advance in the backing layer and then laminated on the skin layer.

The openings can be any shape depending on the desired design, and can be round, oval, polygonal (flat, triangular, etc.), sectoral, cross, hollow, Y-shaped, T-shaped, U-shaped, and other irregular shapes. The arrangement pattern of the openings is not particularly limited and they may be arranged regularly or irregularly, but from the perspective of exerting uniform strength throughout the laminate, it is preferable that they are arranged regularly at predetermined intervals. From the perspective of achieving both breathability and strength of the laminate, the opening diameter is preferably 0.1 mm or more and 3.0 mm or less, and the opening rate is preferably 20% or less from the perspective of maintaining strength, resistance to deformation of the opening holes, and resistance to fraying around the holes.

In the present invention, "opening ratio" refers to the ratio of the area occupied by all openings to the surface area of the laminate.

[Method of manufacturing laminate]
Next, an example of a method for producing a laminate in this embodiment will be given, but various modifications are possible without departing from the gist of the present invention.

(1) Formation of Skin Layer The skin layer of this embodiment is the above-mentioned artificial leather, and it is preferable that this artificial leather is formed by including the following steps.
Step (1-1): Step of forming ultrafine fiber-forming fibers. Step (1-2): Step of forming a fiber structure. Step (1-3): Step of forming ultrafine fibers. Step (1-4): Step of applying polycarbonate-based polyurethane.

Depending on the intended use, it may also be preferable to further include the following steps.
Step (1-5): A step of polishing the sheet-like material. Step (1-6): A step of dyeing the greige material. Step (1-7): Other finishing steps. It goes without saying that the sheet-like material obtained may be used as artificial leather not only if it has undergone only steps (1-1) to (1-4), but also if it has undergone one or more steps of steps (1-5), (1-6), and (1-7) in addition to steps (1-1) to (1-4).
Each step will be described in detail below.

<Step (1-1): Step of forming ultrafine fiber-forming fibers>
In this step, an ultrafine fiber-forming fiber having an islands-in-sea composite structure is formed, which is composed of island portions made of a polyester resin containing a black pigment and/or a chromatic pigment and a sea portion made of an easily soluble polymer. The use of islands-in-sea composite fibers is preferred from the viewpoint of the texture and surface quality of the skin layer, because it allows appropriate voids to be formed between the island portions, i.e., between the ultrafine fibers within the ultrafine fiber bundle, when the sea portion is removed.

The preferred method for spinning ultrafine fiber-generating fibers with an islands-in-sea composite structure is to use an islands-in-sea composite spinning nozzle and a polymer mutual alignment system in which the sea and island portions are mutually aligned and spun, as this produces ultrafine fibers with uniform single fiber fineness.

As a method for incorporating pigment into the island portions, either the pigment and polyester resin may be directly mixed to a predetermined amount, or a masterbatch and polyester resin chips may be mixed and spun. Of these, the method of using a masterbatch to mix with polyester resin chips is preferred, as it allows the amount of pigment contained in the ultrafine fibers to be adjusted appropriately. The pigment content in the masterbatch is preferably in the range of 10% to 40% by mass. The pigment content in the ultrafine fibers is preferably in the range of 0.1% to 2.0% by mass.

The sea portion of islands-in-sea composite fibers can be made from polyethylene, polypropylene, polystyrene, copolymer polyesters copolymerized with sodium sulfoisophthalic acid or polyethylene glycol, and polylactic acid, but polystyrene and copolymer polyesters are preferred from the standpoints of spinnability and ease of elution.

In this process, it is preferable to use islands-in-sea composite fibers with an island portion strength of 2.5 cN/dtex or more. By ensuring that the island portion strength is 2.5 cN/dtex or more, more preferably 2.8 cN/dtex or more, and even more preferably 3.0 cN/dtex or more, the abrasion resistance of the laminate is improved and a decrease in friction fastness due to fiber shedding can be suppressed.

In the present invention, the strength (cN/dtex) of the island parts of the islands-in-sea type composite fiber is measured and calculated by the following method.
(i) Ten islands-in-the-sea composite fibers, each 20 cm long, are bundled together.
(ii) After dissolving and removing the sea portion from the sample (i), the sample is air-dried.
(iii) According to JIS L1013:2010 "Testing methods for chemical fiber filament yarns,""8.5 Tensile strength and elongation,""8.5.1 Standard time test," the test is carried out 10 times under the conditions of a grip length of 5 cm, a pulling speed of 5 cm/min, and a load of 2 N (N=10).
(iv) The arithmetic mean value (cN/dtex) of the test results obtained in (iii) is rounded to one decimal place.

<Step (1-2): Step of forming a fiber structure>
This step is to form a fiber structure containing the ultrafine fiber-developing fibers spun in the above step.

Methods for forming fiber structures include methods for obtaining direct-bonded fiber webs from spinning, such as the spunbonding method and meltblown method, or methods for obtaining fiber sheets by dry methods using staple fibers, such as carding and airlaid methods, or wet methods, such as papermaking. All of these methods are suitable, but fiber sheets produced using staple fibers have small variations in basis weight, excellent uniformity, and are easy to obtain uniform nap, making them ideal for improving the surface quality of artificial leather. Among methods for producing fiber sheets using staple fibers, a particularly preferred method is to form a fiber structure by carding ultrafine fiber-developing fibers with an islands-in-sea composite structure, and then remove the sea portion to produce a fiber structure made of ultrafine fibers. The use of islands-in-sea composite fibers allows for appropriate voids to be created between the island portions that form the fiber structure when the sea portion is removed, i.e., between the ultrafine fibers within the ultrafine fiber bundles, which is preferable from the perspective of the texture and surface quality of the surface layer.

Methods that can be used to entangle the above-mentioned fiber webs or fiber sheets to obtain nonwoven fabrics include needle punching and water jet punching.

As mentioned above, this nonwoven fabric can be in the form of either a short fiber nonwoven fabric or a long fiber nonwoven fabric, but with a short fiber nonwoven fabric, there are more fibers oriented in the thickness direction of the laminate than with a long fiber nonwoven fabric, and when raised, a high degree of density can be achieved on the surface of the skin layer of the laminate.

When this nonwoven fabric is to be a staple fiber nonwoven fabric, the resulting ultrafine fiber-developing fibers are preferably crimped and cut to a predetermined length to obtain raw cotton, which is then opened, laminated, and entangled to obtain a staple fiber nonwoven fabric. Known methods can be used for crimping and cutting. When a staple fiber layer is used in the nonwoven fabric, the staple fiber length is preferably 10 mm or more and 90 mm or less, more preferably 20 mm or more and 80 mm or less, and even more preferably 30 mm or more and 60 mm or less.

Furthermore, if the fiber structure contains woven or knitted fabrics in addition to nonwoven fabric, the nonwoven fabric and woven or knitted fabric obtained as described above are laminated and then entangled together. To entangle the nonwoven fabric and woven or knitted fabric, the woven or knitted fabric can be laminated on one or both sides of the nonwoven fabric, or the woven or knitted fabric can be sandwiched between multiple nonwoven fabric webs, and the fibers of the nonwoven fabric and woven or knitted fabric can then be entangled together using a needle punching process, water jet punching process, or the like.

The apparent density of the fiber structure obtained by needle punching or water jet punching is preferably 0.15 g/ ^cm3 or more and 0.45 g/ ^cm3 or less. By setting the apparent density to preferably 0.15 g/ ^cm3 or more, a laminate having a surface skin that can easily follow complex shapes without tearing, even when partially stretched by molding, can be obtained. On the other hand, by setting the apparent density to preferably 0.45 g/ ^cm3 or less, sufficient space can be maintained for applying polycarbonate-based polyurethane.

It is also a preferred embodiment to subject the above-mentioned fiber structure to a heat shrinking treatment using hot water or steam to improve the density of the fibers.

Next, the fiber structure can be impregnated with an aqueous solution of a water-soluble resin such as polyacrylamide (PAA), polyvinyl alcohol (PVA), or carboxymethyl cellulose, followed by drying, to impart a water-soluble resin. By imparting a water-soluble resin to the fiber structure before step (1-3), the "step of forming ultrafine fibers," the fibers are fixed, resulting in a fiber structure that is less susceptible to dimensional changes due to process tension, etc., even after the ultrafine fibers are formed. As a result, the nap density is maintained, resulting in a laminate with a surface that maintains an even denser nap appearance. On the other hand, by imparting a water-soluble resin after step (1-3), the "step of forming ultrafine fibers," and before step (1-4), the "step of imparting polycarbonate-based polyurethane," the polycarbonate-based polyurethane is prevented from firmly adhering to the ultrafine fibers, resulting in a laminate with a flexible surface that can more easily conform to the molding die. If a water-soluble resin has been applied, it can be removed by immersing the substrate in an organic solvent containing DMF, dimethyl sulfoxide, or the like in step (1-4) of applying the polycarbonate-based polyurethane.

<Step (1-3): Step of forming ultrafine fibers>
In this step, the obtained fiber structure is treated with a solvent to produce ultrafine fibers having a single fiber diameter of 15 μm or less, more preferably an average single fiber diameter of 0.1 μm or more and 10.0 μm or less.

The ultrafine fiber development process can be carried out by immersing the fiber structure obtained in step (1-2) in a solvent to dissolve and remove the sea portion of the islands-in-sea composite fiber in the fiber structure.

When the sea portion is polyethylene, polypropylene, or polystyrene, organic solvents such as toluene or trichloroethylene can be used as the solvent for dissolving and removing the sea portion. When the sea portion is copolymer polyester or polylactic acid, an alkaline aqueous solution such as sodium hydroxide can be used. When the sea portion is a water-soluble thermoplastic polyvinyl alcohol resin, hot water can be used.

<Step (1-4): Step of applying polycarbonate-based polyurethane>
In this step, the fiber structure obtained in step (1-2) or the fiber structure that has been subjected to step (1-3) is impregnated with a solution of polycarbonate-based polyurethane to fix the polycarbonate-based polyurethane to the fiber structure, thereby providing the polycarbonate-based polyurethane. The polycarbonate-based polyurethane referred to here is the one described above.

Preferred solvents for applying polycarbonate-based polyurethane include DMF and dimethyl sulfoxide. Alternatively, an aqueous dispersion of polycarbonate-based polyurethane dispersed in water as an emulsion may be used.

After the fiber structure has been impregnated with the polycarbonate-based polyurethane solution, methods for fixing the polycarbonate-based polyurethane to the fiber structure include wet coagulation, in which the solvent is replaced with water if the polyurethane solution is an organic solvent such as DMF or dimethyl sulfoxide, or with an organic solvent such as DMF or dimethyl sulfoxide if the polyurethane solution is water-based, and the solution is coagulated; or dry coagulation, in which the polyurethane solution is dried with heat and coagulated. These methods can be selected appropriately depending on the type of polycarbonate-based polyurethane used.

The polyurethane may be applied to the fibrous structure material substrate before generating ultrafine fibers from the ultrafine fiber-generating fibers (i.e., immediately after step (1-2)), or after generating ultrafine fibers from the ultrafine fiber-generating fibers (i.e., after step (1-3) and before step (1-5)).

<Step (1-5): Step of polishing sheet-like material>
In this step, at least one surface of the sheet-like material to which the polycarbonate-based polyurethane has been applied, obtained after the steps (1-1) to (1-4), can be polished. From the viewpoint of production efficiency, it is also a preferred embodiment to cut the sheet-like material in half in the thickness direction to obtain two sheet-like materials prior to this polishing.

Furthermore, the polishing is preferably carried out using sandpaper, a roll sander, or the like. This allows for the production of a green fabric. As mentioned above, this polishing can be carried out on only one surface of the sheet-like material, or on both surfaces.

When sanding, it is also preferable to apply a lubricant such as silicone emulsion to the surface of the sheet-like material before sanding. Also, applying an antistatic agent before sanding makes it less likely that grinding dust generated from the sheet-like material during grinding will accumulate on the sandpaper.

<Step (1-6): Step of dyeing the green fabric>
In this step, the grey fabric is dyed. In this case, a mode in which no dyeing is performed is also preferred. Considering discoloration due to exposure to molding, thermal history, and the like, the most preferred mode is to use no dye or only the small amount required for color matching. When dyeing is performed, examples of dyeing methods that can be used include jet dyeing using a jigger dyeing machine or jet dyeing machine, immersion dyeing such as thermosol dyeing using a continuous dyeing machine, or printing on a napped surface using roller printing, screen printing, inkjet printing, sublimation printing, vacuum sublimation printing, and the like. Of these, jet dyeing machines are preferred because they provide a soft texture and are superior in quality and grade.

<Step (1-7): Other finishing steps>
If necessary, the obtained sheet material or green fabric may be subjected to various resin finishing processes, such as coating.

Methods for forming a resin layer on at least a portion of the surface layer, as described above, include, for example, a method of forming a resin layer by coating using a screen method such as a flat screen or rotary screen, or by gravure coating, followed by drying; or a method of forming a discontinuous resin film on a supporting substrate such as release paper, applying an adhesive to the surface of the resin film, adhering it to the surface of the substrate, and then removing the release paper to form a resin layer.

Incidentally, this resin layer can also be formed after the skin material and backing layer have been laminated together with an adhesive resin interposed between them. Even in this case, the laminate will naturally still "have a resin layer on at least a portion of the surface of the skin layer."

Other finishing processes include, for example, adding finishing agents such as softeners or antistatic agents after dyeing, finishing processes that impart functionality such as antibacterial agents or flame retardants, post-processing such as perforation, embossing, laser processing, pinsonic processing, and printing. Even if these processes are performed, the material is still considered to be a skin material within the scope of this invention.

<Epidermal layer>
Here, more preferred aspects of the properties of the skin layer obtained by the above steps will be described.

In this embodiment, the skin layer preferably has a bending resistance in the longitudinal direction of 40 mm or more and 300 mm or less. By having the bending resistance in the longitudinal direction of the skin layer preferably be 40 mm or more, more preferably 50 mm or more, and even more preferably 55 mm or more, a laminate with higher strength can be obtained. On the other hand, by having the bending resistance in the longitudinal direction of the skin layer preferably be 300 mm or less, more preferably 250 mm or less, and even more preferably 200 mm or less, the occurrence of wrinkles and sagging during the lamination process with the backing layer can be further suppressed, and the operability of the lamination process can be further improved.

In the present invention, the bending resistance of the skin layer in the longitudinal direction is measured and calculated by the following method.
(i) When measuring from a laminate, carefully peel off the surface layer and remove the layers other than the surface layer of the backing material layer. If a surface layer alone before lamination is obtained, evaluation can be performed from (ii) without performing the above-mentioned removal work.
(ii) Five test pieces of 30 x 2 cm are taken lengthwise from any location in the epidermal layer.
(iii) The surface layer is measured based on Method A (45° cantilever method) described in 8.21.1 of "Bending resistance" in JIS L1096:2010 "Testing methods for woven and knitted fabrics," and the average value of five sheets is calculated.

In the present invention, the longitudinal direction of the skin layer is determined by the following method. When the longitudinal direction can be determined from the appearance of the skin layer, that is, when the winding direction of the skin layer roll can be uniquely determined, this direction is taken as the longitudinal direction. On the other hand, when the longitudinal direction cannot be determined from the appearance, such as when the skin layer is cut and is not in a rolled state, the longitudinal direction is determined by the following procedure.
(i) One arbitrary direction is determined within the plane of the surface layer, and the test is conducted along that direction according to "6.3.1 Tensile strength and elongation (ISO method)" of JIS L1913:2010 "Testing methods for general nonwoven fabrics." (ii) The test is also conducted in the same way in directions rotated 30 degrees, 60 degrees, and 90 degrees from the direction tested in (i).
(iii) The maximum strength of each test piece is measured and used as the tensile strength of the skin layer in each direction.
(iv) The direction in which the measured value is the highest is taken as the longitudinal direction of the skin layer. If there are two or more directions in which the tensile strength is highest, the direction in which the tensile strength is lower in a direction perpendicular to those directions is taken as the longitudinal direction of the skin layer. If there are two or more directions in which the tensile strength is highest and the tensile strengths in the directions perpendicular to those directions are also equal, for example, if the tensile strengths in all four directions are equal, any of the four directions is taken as the longitudinal direction.

In this embodiment, the surface layer preferably has a basis weight of 50 g/ ^m2 or more and 400 g/ ^m2 or less. By setting the basis weight of the surface layer to 50 g/ ^m2 or more, more preferably 80 g/ ^m2 or more, the surface layer can have a solid feel and a superior texture. On the other hand, by setting the basis weight to 400 g/ ^m2 or less, more preferably 300 g/ ^m2 or less, the surface layer can have excellent formability and flexibility, and the laminate can also be made more flexible.

The basis weight of the skin layer in the present invention is measured in accordance with "6.2 Mass per unit area (ISO method)" of JIS L1913:2010 "Testing methods for general nonwoven fabrics," and is measured and calculated as follows.
(i) Three test pieces, each 30 cm long and 30 cm wide, are randomly taken from the skin layer to be used in the laminate.
(ii) The mass of the test piece of (i) is measured.
(iii) Calculate the mass per unit area of each test piece using the following formula:
Mass per unit area (g/m ² )=mass of test piece (g)/area of test piece (m ² ) (formula).
(iv) The arithmetic mean value of the mass per unit area (g/m ² ) obtained in (iii) is rounded down to an integer.

(2) Formation of Laminate The laminate of this embodiment can be produced by a method including the steps of applying an adhesive to one surface of sheet A, which will serve as the backing layer, placing sheet B, which will serve as the skin layer, on the surface to which the adhesive has been applied, and curing the adhesive to integrate sheets A and B via an adhesive resin, which is the cured product of the adhesive.

When applying the adhesive, it can be diluted as needed. The diluent can be selected from toluene, xylene, ethyl acetate, etc., but water is preferable when considering the emission of volatile organic compounds (VOCs). Using a water-based adhesive can reduce the VOCs emitted when the adhesive is dried, and can also reduce VOC emissions from the resulting laminate.

As mentioned above, the adhesive used in this process can be selected appropriately depending on the material and form of the backing layer. For example, it can be selected appropriately from adhesives that can be used as adhesive resins, such as polyurethane resins, acrylic resins, silicone resins, olefin resins, polyamide resins, epoxy resins, vinyl chloride resins, and polyester resins. In other words, it can be an embodiment in which the resin is used as an adhesive component itself, such as a non-reactive hot melt adhesive, or an embodiment in which the adhesive before application is composed of unreacted substances that form the resin, and reacts to become the resin after application; therefore, as mentioned above, it is referred to as an "adhesive that can be used as an adhesive resin."

In particular, when considering flexibility and adhesive strength at high temperatures, it is preferable to use an adhesive that can be made of polyurethane resin or acrylic resin as the adhesive resin. It is even more preferable to use an adhesive that can be made of polyurethane resin, which provides high adhesive strength and high flexibility.

The adhesive used in this process can be a solvent-based adhesive that hardens when the solvent evaporates, a moisture-curing adhesive, a reactive adhesive such as a two-component adhesive, or a hot melt adhesive such as a reactive hot melt adhesive or a non-reactive hot melt adhesive, with two-component adhesives being preferred.

Among these, from the standpoint of workability, it is more preferable to use a two-component polyurethane adhesive made from an isocyanate compound and a polyol compound as the adhesive. Two-component polyurethane adhesives that incorporate an isocyanate compound and a chain extender are preferred. When using this two-component polyurethane adhesive, the crosslinking reaction continues even after the surface layer and backing layer are temporarily bonded, which makes it easier for the isocyanate compound to crosslink with the adhesive resin of the polycarbonate-based polyurethane of Sheet B, which will form the surface layer, resulting in better peel strength between the surface layer and backing layer.

In addition to the isocyanate compound and polyol compound, this two-component polyurethane adhesive may also contain additives such as chain extenders, catalysts, solvents (e.g., organic solvents such as water, DMF, and toluene), thickeners, and antistatic agents, as needed.

The adhesive, which may be a urethane-based resin, is preferably a mixture of 5 to 30 parts by weight of an isocyanate compound per 100 parts by weight of the polyol compound, which is the main component. By using 5 parts by weight or more of the isocyanate compound, a crosslinking reaction can be easily induced between the polyol compound in the adhesive and the polycarbonate-based polyurethane contained in Sheet B, resulting in a laminate with higher peel strength between the skin layer and the backing layer. On the other hand, by using 30 parts by weight or less of the isocyanate compound, the pot life of the adhesive can be further extended, improving operability.

The laminate of this embodiment can be manufactured by a method including the steps of applying an adhesive to one surface of Sheet A, which will serve as the backing layer, placing Sheet B, which will serve as the skin layer, on the adhesive-coated surface, and curing the adhesive to integrate Sheet A and Sheet B via the adhesive resin resulting from the cured adhesive. It is also possible to apply an adhesive to one surface of Sheet B, which will serve as the skin layer. However, in this case, the coating method, coating amount, and type of adhesive should be adjusted, taking into consideration that the adhesive resin may seep to the surface of the outermost skin layer, hardening the surface. Even when woven or knitted fabrics or nonwoven fabrics are used as Sheet A, adhesive resin seepage is a concern. However, since the adhesive resin is applied to the back side, applying it to one side of Sheet A is preferred, as it is less likely to affect the appearance. If seepage is a concern for Sheet A, the coating method, coating amount, and type of adhesive can be adjusted to achieve the desired properties. When a foam resin sheet is used as Sheet A, adhesive resin seepage is less likely to occur. Using a foamed resin sheet as Sheet A is a preferred embodiment from the standpoint of processability in addition to the advantages mentioned above.

Methods for applying the adhesive to one surface of sheet A, which will become the backing layer, include gravure coating, knife coating, screen methods using a flat screen or rotary screen, spray coating, etc., followed by drying to harden the adhesive, and methods for applying the adhesive to a support substrate such as release paper to form an adhesive sheet, then laminating the adhesive sheet to the surface of the backing material, and then removing the release paper to transfer the adhesive. A preferred method is to transfer the adhesive to one surface of sheet A, which will become the backing layer, using a transfer method using release paper; this reduces variations in the amount of adhesive applied due to differences in the surface smoothness and thickness of the backing material, and allows for a uniform application of the adhesive.

When applied to the backing layer, the coating amount of adhesive is preferably 15 g/ ^m2 or more and 500 g/ ^m2 or less, calculated as the solid content of the adhesive that hardens to become the adhesive resin. By setting this coating amount to preferably 15 g/ ^m2 or more, more preferably 20 g/ ^m2 or more, the peel strength at high temperatures is further improved. On the other hand, by setting the coating amount to preferably 500 g/ ^m2 or less, more preferably 400 g/ ^m2 or less, the moldability of the laminate is further improved.

In this embodiment, the basis weight of the sheet A serving as the backing layer is preferably in the range of 120 g/ ^m² or more and 500 g/ ^m² or less. By setting the basis weight of the sheet A to 120 g/ ^m² or more, more preferably 140 g/ ^m² or more, a laminate having better peel strength and material strength and better shape retention after molding is obtained. On the other hand, by setting the basis weight to 500 g/ ^m² or less, more preferably 400 g/ ^m² or less, a more flexible laminate having better moldability is obtained.

The basis weight of sheet A, which serves as the backing layer in this embodiment, is measured in accordance with "6.2 Mass per unit area (ISO method)" of JIS L1913:2010 "Testing methods for general nonwoven fabrics," and is measured and calculated as follows.
(i) Three test pieces measuring 30 cm long x 30 cm wide are taken at random from the backing layer to be used in the laminate before lamination.
(ii) The mass of the test piece of (i) is measured.
(iii) Calculate the mass per unit area of each test piece using the following formula:
Mass per unit area (g/m ² )=mass of test piece (g)/area of test piece (m ² ) (formula).
(iv) The arithmetic mean value of the mass per unit area (g/m ² ) obtained in (iii) is rounded down to an integer.

Then, the adhesive-coated surface of Sheet A, which will serve as the backing layer, is superimposed on the back surface of Sheet B, which will serve as the skin (the surface of the laminate that does not serve as the design surface), and pressed together to obtain a laminate. This pressing is preferably performed using a press, dry heat pressing with a calendar roll, or wet heat pressing, allowing for continuous laminate production. More preferably, wet heat pressing with a calendar roll is used, which activates the molecular motion of the adhesive between Sheet A, which will serve as the backing layer, and Sheet B, which will serve as the skin layer, as well as the polyurethane of Sheet B, which will serve as the skin layer, thereby achieving high peel strength between the skin layer and the backing layer. Furthermore, in this embodiment, the polycarbonate-based polyurethanes of the skin layer each contain different aliphatic hydrocarbon groups, which makes the polycarbonate-based polyurethane more likely to have an amorphous structure and further activates molecular motion, resulting in high peel strength between the skin layer and the backing layer.

When pressing with a press, the temperature of the mold surface should preferably be between 40°C and 200°C. A temperature of 40°C or higher, and more preferably 60°C or higher, softens the adhesive, further increasing the molecular motion of the adhesive between the backing layer and skin layer, and of the polyurethane in the skin layer, facilitating the crosslinking reaction caused by the adhesive, resulting in higher peel strength between the skin layer and backing layer. On the other hand, a temperature of 200°C or lower, and more preferably 140°C or lower, results in a high-quality laminate.

The pressure of the press at this time is preferably 0.1 MPa or more and 10 MPa or less. By setting it to preferably 0.2 MPa or more, and more preferably 0.3 MPa or more, the adhesive can more easily penetrate into the ultrafine fiber bundles, further improving the peel strength. On the other hand, by setting it to preferably 9 MPa or less, and more preferably 8 MPa or less, superior moldability can be achieved, resulting in a laminate of even better quality.

The temperature of the calendar roll when performing dry heat pressing is preferably 40°C or higher and 200°C or lower. A temperature of 40°C or higher, more preferably 60°C or higher, increases the molecular motion of the adhesive between the backing layer and skin layer, and of the polyurethane in the skin layer, resulting in higher peel strength between the skin layer and backing layer. On the other hand, a temperature of 200°C or lower, more preferably 140°C or lower, results in a laminate of even higher quality.

Furthermore, the pressure of the calendar roll during this process is preferably 10 N/cm or more and 1000 N/cm or less. By setting it to preferably 20 N/cm or more, and more preferably 30 N/cm or more, the adhesive can more easily penetrate into the ultrafine fiber bundles, improving the peel strength. On the other hand, by setting it to preferably 900 N/cm or less, and more preferably 800 N/cm or less, a laminate with excellent moldability and high quality can be obtained.

On the other hand, when wet heat pressing is performed using a calendar roll, the steam temperature is preferably 40°C or higher, and more preferably 60°C or higher, which softens the adhesive and further activates the molecular motion of the adhesive between the backing layer and skin layer, and of the polyurethane in the skin layer, thereby achieving high peel strength between the skin layer and backing layer. On the other hand, the steam temperature is preferably 100°C or lower, and more preferably 90°C or lower, resulting in a laminate of even better quality.

The pressure applied by the calendar rolls in this case is the same as that used when dry heat bonding.

[Interior materials, vehicle parts, furniture]
The laminate of the present invention can be formed into any shape by press molding, and since the surface layer has excellent color development and friction fastness even after molding, it is suitable for use in a variety of applications, including interior materials, vehicle parts, and furniture.

In particular, interior materials containing the laminate are preferred because they can maintain the high quality of the surface layer even after high-temperature press molding and can take advantage of the property of having sufficient peel strength. Examples of such interior materials include seat covers, ceiling materials, and wall materials for seats in the interiors of vehicles such as automobiles, trains, and airplanes.

Also, vehicle parts containing the laminate are similarly preferable, as they can take advantage of the property that the high quality of the skin layer can be maintained even after high-temperature press molding. Examples of such vehicle parts include parts for automobiles, trains, and aircraft, such as steering wheels, shift levers, handbrakes, control handles, and joysticks.

Furniture containing the laminate is also preferable, as it can take advantage of the property that the high quality of the surface layer can be maintained even after high-temperature press molding. Examples of such furniture include chairs, tables, and storage furniture.

Next, the present invention will be specifically explained based on examples. However, the present invention is not limited to these examples.

[Measurement method]
The evaluation methods and measurement conditions used in the examples are explained below. Unless otherwise specified, the measurements of each physical property were carried out according to the above-mentioned methods.

(1) Physical properties of the surface layer (1-1) Physical properties of the fiber structure (1-1-1) Average particle size (μm) and coefficient of variation of particle size (%) of black pigment and chromatic pigment contained in ultrafine fibers
The average particle diameters (μm) of the black pigment and the chromatic pigment contained in the ultrafine fibers were measured and calculated by the above-described method using a transmission electron microscope (TEM) "H7700" manufactured by Hitachi High-Technologies Corporation and image analysis software "VW-9000" manufactured by Keyence Corporation.

(1-1-2) Pigment content in ultrafine fibers (mass%)
The content (mass%) of the pigment in the ultrafine fibers was determined by the method described above. Specifically, the content was calculated from the manufacturing process.

(1-1-3) Average single fiber diameter of ultrafine fibers (μm)
The average single fiber diameter (μm) of the ultrafine fibers was measured and calculated by the above-mentioned method using a scanning electron microscope (SEM) "VHX-D500/D510" manufactured by Keyence Corporation.

(1-2) Physical properties of polycarbonate-based polyurethane (1-2-1) Content of polycarbonate-based polyurethane in the skin layer (mass%)
The content (mass %) of polycarbonate-based polyurethane in the surface layer was measured and calculated by the method described above.

(1-3) Physical properties of the surface layer (1-3-1) Pile length of artificial leather (μm)
The nap length (μm) was measured and calculated by the above-mentioned method using a scanning electron microscope (SEM) "VHX-D500/D510" manufactured by Keyence Corporation.

(1-3-2) Dye content (mass%)
The content (mass %) of the dye in the skin layer was measured and calculated by the method described above.

(1-3-3) Pile coverage (%), surface area ratio of resin layer (%)
The nap coverage rate (%) and the area ratio (%) of the resin layer on the surface were measured and calculated by the above-mentioned method using a SEM "VHX-D500/D510 type" manufactured by Keyence Corporation and image analysis software "ImageJ" from the National Institutes of Health (NIH).

(1-3-4) Bending resistance in the longitudinal direction (mm)
The bending resistance (mm) of the skin layer in the longitudinal direction was measured and calculated by the method described above.

(1-3-5) Thickness (mm)
The thickness (mm) of the skin layer was measured and calculated using a SEM "VHX-D500/D510" manufactured by Keyence Corporation, according to the method described above.

(1-3-6) Basis weight (g/m ² )
The basis weight (g/m ² ) of the skin layer was measured and calculated by the method described above.

(2) Physical properties of the backing layer (2-1) Thickness (mm)
The thickness (mm) of the backing layer was measured and calculated using a SEM "VHX-D500/D510" manufactured by Keyence Corporation, according to the method described above.

(2-2) Basis weight (g/m ² )
The basis weight (g/m ² ) of the backing layer was measured and calculated by the method described above.

(3) Physical properties of adhesive resin (3-1) Thickness (mm)
The thickness (mm) of the adhesive resin was measured and calculated using a SEM "VHX-D500/D510" manufactured by Keyence Corporation, according to the method described above.

(3-2) Coating amount (g/m ² )
The amount of adhesive resin applied (g/m ² ) was determined by measuring the mass of the backing layer before and after applying the adhesive resin when producing the laminate. Specifically, the amounts are as follows (a) to (c):
(a) Before the adhesive resin was applied, three 10 cm x 10 cm test pieces were taken from the backing layer at random positions in the vertical direction, 10 cm from the center in the width direction, and 10 cm from the right and left ends, and the basis weight (g/ ^m2 ) of the backing layer before the adhesive resin was applied was calculated from the number average value of their masses.
(b) Next, after applying the adhesive resin to the backing layer, three 10 cm x 10 cm test pieces were similarly taken from the backing layer before bonding it to the skin layer at random positions in the vertical direction, from the center in the width direction and 10 cm from the right and left ends, and the basis weight (g/ ^m2 ) of the backing layer after applying the adhesive resin was calculated from the number average of their masses.
(c) Finally, the difference (g/ ^m2 ) between the basis weight (g/m2) of the backing layer after applying the adhesive resin and the basis weight (g/ ^m2 ) of the backing layer before applying the adhesive resin was rounded to the first decimal place ^, and the resulting value was taken as the amount of adhesive resin applied (g/ ^m2 ).

(3-3) Viscosity of adhesive resin (Pa s)
The viscosity (Pa s) of the adhesive resin was measured before application using a "B-type viscometer" manufactured by Tokyo Keiki Co., Ltd., while maintaining the temperature at 25°C, in accordance with JIS K7117:1999 "Plastics - Liquid, emulsion or dispersion resins - Measurement of apparent viscosity using a Brookfield rotational viscometer."

(4) Physical properties of laminate (4-1) Thickness (mm)
The thickness (mm) of the laminate was measured and calculated using a "Peacock Dial Thickness Gauge H" manufactured by Ozaki Seisakusho Co., Ltd. as a thickness measuring instrument, according to the method described above.

(4-2) Weight (g/m ² )
The basis weight (g/m ² ) of the laminate was measured and calculated by the method described above.

(4-3) Breakdown mode when attempting to peel, peel strength when peeling (N/cm)
The evaluation of the fracture mode when attempting to peel and the peel strength (N/cm) when peeling were carried out using a tensile tester "Model: 3343" manufactured by Instron Corporation, and were evaluated, measured, and calculated according to the above-mentioned method.

(4-4) Coloring Property The coloring property of the laminate was evaluated by 10 healthy adult panelists according to the following criteria, and the evaluation result with the largest number of participants was adopted. In the present invention, a good level is "Grade 4 to Grade 5".
Grade 5: The color was very vivid, or the color depth and brightness were outstanding, and the appearance was good.
Grade 4: A rating between Grade 5 and Grade 3.
Grade 3: Overall the color is vivid, but there are some areas that are not so good.
Grade 2: A rating between Grade 3 and Grade 1.
Grade 1: Overall impression was dull and the appearance was poor.

(4-5) Surface quality (grade)
The surface quality of the laminate was evaluated by 10 healthy adult panelists using the following criteria, with the result with the largest number of participants being adopted. The surface quality was evaluated by placing the laminate (23) on an inspection table (22) parallel to the floor (21) as shown in Figure 2, and visually inspecting the laminate (23) at a 45° angle from the plane of the inspection table so that the length of the line (25) connecting the visual inspection position (24) and the laminate (23) was 50 cm. A 32 W fluorescent lamp (26) was installed on the inspection table, 150 cm above the top surface of the inspection table in the vertical direction. The surface quality evaluation was performed by placing the laminate (23) directly below the fluorescent lamp (26), i.e., in a position where a perpendicular line (27) could be drawn from the laminate to the fluorescent lamp. Grades 4 to 5 of surface quality were considered to be good.
Grade 5: The fibers were uniformly raised, the fiber dispersion was good, and the appearance was good.
Grade 4: A rating between Grade 5 and Grade 3.
Grade 3: The fiber standing condition was somewhat poor in some areas.
Grade 2: A rating between Grade 3 and Grade 1.
Grade 1: Overall, the nap and dispersion of the fibers were very poor, and the appearance was poor.

(4-6) Evaluation of bent parts after press forming (grade)
To evaluate the bent portion after press molding, a top-hat-shaped molded specimen with a diameter of 45 mm, a height of 10 mm, and a maximum expansion ratio of 120% was prepared using a male/female cylindrical container lid mold, and the evaluation was performed. Specifically, the laminate was placed in an oven heated to 200°C for 5 minutes, and then pressed at a pressure of 0.1 MPa for 30 seconds using a heated press set to 55°C to obtain a molded specimen. The appearance quality of the bent portion of this specimen was visually evaluated, with grades 4 to 5 being considered good. The expansion ratio was calculated using the following steps (a) to (d).
(a) Ten evaluation samples each having an A4 size (210 mm x 297 mm) were taken from any position of the laminate before molding.
(b) A 5 mm x 5 mm grid was drawn on the surface of the epidermis layer side of the collected evaluation sample.
(c) The area of the grid drawn on the surface layer side of the evaluation sample obtained by molding was measured using a digital microscope, "VHX-5000" manufactured by Keyence Corporation, with the magnification adjusted to 20 times.
(d) The area of the measured square was divided by the original area before molding to obtain the expansion rate (%).
Grade 5: Appearance was very good (no deterioration in quality due to increased exposure of polyurethane on the surface of the laminate after processing).
Grade 4: A rating between Grade 5 and Grade 3.
Grade 3: Fair (the amount of polyurethane exposed on the surface of the laminate after processing has increased, and a deterioration in quality is observed.)
Grade 2: A rating between Grade 3 and Grade 1.
Grade 1: The appearance was poor (the amount of exposed polyurethane on the surface of the laminate after processing was greatly increased, and the quality was significantly reduced).

(4-7) Discoloration evaluation (grade) after press molding
For the evaluation (grade) of discoloration after press molding, the laminate was left to stand in an oven heated to 200°C for 5 minutes, and then pressed at a pressure of 0.1 MPa for 30 seconds using a heated press set to 55°C to obtain a laminate sample. This sample was compared with the skin before molding and judged using the gray scale for discoloration specified in JIS L0804:2004 "Gray scale for discoloration," with grade 4 or higher being considered a pass.

(4-8) Rubbing fastness (grade)
A 30 x 200 mm test piece was taken from the laminate and attached to a Gakushin Type II friction tester (JIS L0849:2013 "Test method for color fastness to friction"). White cotton cloth representing each dry and sweaty condition was placed over the friction element, the friction load was set to 1.96 N, and the test piece was rubbed 200 times at a speed of 30 reciprocations per minute over a distance of 100 mm. After the test, the degree of staining of the sample after the friction test was evaluated using the staining gray scale specified in JIS L0805:2005 "Staining Gray Scale," with a grade of 4 or higher being considered a pass. The sweat cloth was a white cotton cloth immersed in artificial sweat for 10 minutes. The artificial sweat solution was prepared by dissolving the following in distilled water to make 1 L.
Disodium hydrogen phosphate dodecahydrate as defined in JIS K9019:2021 "Disodium hydrogen phosphate dodecahydrate (reagent)": 8 g
Sodium chloride as specified in JIS K8150:2006 "Sodium chloride (reagent)": 8 g
Acetic acid: 5 g, as specified in JIS K8355:2006 "Acetic acid (reagent)".

[Notation of chemical substances, etc.]
The abbreviations for chemical substances used in the examples and comparative examples have the following meanings:
(ultrafine fiber resin)
PET: polyethylene terephthalate PLA: polylactic acid (pigment)
CB: Carbon black (resin related to ultrafine fibers)
P1: polyethylene terephthalate having an intrinsic viscosity (IV value) of 0.72; P2: the masterbatch P1 containing carbon black (average particle size: 0.02 μm, coefficient of variation (CV) of particle size: 20%) as a black pigment at 20% by mass relative to the mass of the masterbatch; P3: polylactic acid having a melt flow rate (MFR) of 30 g/10 min, a melting point of 170° C., and a solid density of 1.240 g/cm ³ ; P4: the masterbatch P3 containing carbon black (average particle size: 0.02 μm, coefficient of variation (CV) of particle size: 20%) as a black pigment at 20% by mass relative to the mass of the masterbatch; P5: the masterbatch P1 containing cobalt aluminate (average particle size: 0.05 μm, coefficient of variation (CV) of particle size: 30%) as a blue pigment. 3490E") in an amount of 20 mass% relative to the mass of the masterbatch (polycarbonate-based polyurethane)
PCPU: Polycarbonate polyurethane C9/C8 _2m : Copolymerized polycarbonate diol represented by the following general formula (4), derived from 1,9-nonanediol and 2-methyl-1,8-octanediol, and having a number average molecular weight of 2,000

(wherein n and m are positive integers, and the copolymer is a random copolymer. R represents an aliphatic hydrocarbon group of either (CH ₂ ) ₉ or CH ₂ —CH(CH ₃ )—(CH ₂ ) _6. )
C6/C5 _3m : A copolymer polycarbonate diol having a number average molecular weight of 2000, represented by the following general formula (5) and derived from 1,6-hexanediol and 3-methyl-1,5-pentanediol.

(wherein x and y are positive integers and the copolymer is a random copolymer; R represents an aliphatic hydrocarbon group of either (CH ₂ ) ₆ or (CH ₂ ) ₂ —CH(CH ₃ )—(CH ₂ ) _2. )
C6/C6: A copolymeric polycarbonate diol having a number average molecular weight of 2000, represented by the following general formula (6), and derived from 1,6-hexanediol.

(wherein x and y are positive integers, and the copolymer is a random copolymer. R represents an aliphatic hydrocarbon group of (CH ₂ ) _6. )
C4/C10: A copolymer polycarbonate diol represented by the following general formula (7), derived from 1,4-butanediol and 1,10-decanediol, and having a number average molecular weight of 2,000.

(wherein x and y are positive integers, and the copolymer is a random copolymer. R represents an aliphatic hydrocarbon group, either (CH ₂ ) ₄ or (CH ₂ ) _10. )
PTMG: Polytetramethylene glycol with a number average molecular weight of 2000 PCL: Polycaprolactone diol with a number average molecular weight of 2000 (others)
MDI: 4,4'-diphenylmethane diisocyanate DMF: N,N-dimethylformamide PU: polyurethane EG: ethylene glycol.

The following Production Examples 1 to 4 show examples of how to produce polyurethane solutions used in the Examples and Comparative Examples.

[Production Example 1]
As polyols, 60 parts by mass of C9/C8 _2m and 40 parts by mass of C6/C5 _3m ,
MDI as the organic diisocyanate,
DMF was used as a solvent in a four-neck separable flask equipped with a condenser so that the molar ratio of total polyol to MDI was 1:3, and the mixture was stirred and reacted under a nitrogen atmosphere while maintaining the temperature in the range of 40°C to 60°C.

Then, EG was diluted in DMF as a chain extender and added dropwise while maintaining the temperature between 50°C and 60°C, and the mixture was allowed to react. It was then gradually diluted with DMF, and after approximately 10 hours, a polycarbonate-based polyurethane solution with a solids content of 25% was obtained.

Furthermore, this was diluted with DMF to adjust the solids concentration to 13% by mass, yielding a DMF solution S1 of polycarbonate-based polyurethane X.

[Production Example 2]
A DMF solution S2 of polyurethane α was obtained in the same manner as in Production Example 1, except that 70 parts by mass of PTMG and 30 parts by mass of PCL were used as the polyols.

[Production Example 3]
A DMF solution S3 of polyurethane β was obtained in the same manner as in Production Example 1, except that 100 parts by mass of C6/C6 was used as the polyol.

[Production Example 4]
A DMF solution S4 of polycarbonate-based polyurethane Y was obtained in the same manner as in Production Example 1, except that 60 parts by mass of C9/C8 _2m and 40 parts by mass of C6/C6 were used as the polyols.

[Production Example 5]
A DMF solution S5 of polycarbonate-based polyurethane Y was obtained in the same manner as in Production Example 1, except that 50 parts by mass of C4/C10 and 50 parts by mass of C6/C5 _3m were used as the polyols.

[Example 1]
(1) Formation of epidermal layer <Step of forming ultrafine fiber-forming fibers>
The sea component was made of polystyrene, and the island component was made of a polymer obtained by mixing P1 and P2 in a mass ratio of P1:P2 = 95:5. The sea component was 20 mass% and the island component was 80 mass%, and the number of islands was 16 per filament. The ultrafine fiber-forming fiber was then drawn 2.7 times in a spinning oil bath at 90°C to obtain an islands-in-sea type composite fiber having an average single fiber diameter of 20 µm.

<Step of forming a fiber structure>
Next, the obtained islands-in-sea type composite fibers were cut into staples with a fiber length of 51 mm, which were passed through a card and a cross wrapper to form a fiber web, which was then needle-punched to produce a fiber structure (short-fiber nonwoven fabric) with a thickness of ^2.1 mm and an apparent density of 0.22 g/cm.

<Step of forming ultrafine fibers>
The obtained fiber structure was immersed in trichloroethylene and squeezed with a mangle, which was repeated 10 times to obtain a sheet made of ultrafine fibers from which the sea component of the islands-in-sea type composite fibers had been removed.

<Step of applying polycarbonate-based polyurethane>
The sheet made of the ultrafine fibers was immersed in a DMF solution S1 of polycarbonate-based polyurethane X, and then the sheet immersed in the DMF solution S1 of polycarbonate-based polyurethane X in an aqueous solution with a DMF concentration of 30% by mass was immersed in hot water at 90°C to remove the DMF, thereby solidifying the polycarbonate-based polyurethane X. Thereafter, the sheet was dried with hot air at a temperature of 110°C for 10 minutes, thereby obtaining a sheet-like material to which the polycarbonate-based polyurethane X was imparted.

<Step of polishing sheet-like object>
The sheet-like material obtained as described above was sliced perpendicularly to the thickness direction to cut it in half, and the non-cut surface (the surface opposite to the surface formed by cutting in half) was ground with sandpaper of sandpaper count 180 to obtain a green fabric having raised nap.

<Process of dyeing grey fabric>
The thus obtained greige fabric was dyed with a black dye using a jet dyeing machine at a temperature of 120°C. It was then dried in a dryer to obtain an artificial leather with an average single fiber diameter of 4.4 µm, a thickness of 0.7 mm, a basis weight of 226 g/ ^m2 , and a nap coverage of 85%. The dye content in the resulting artificial leather was 3% by mass.

(2) Formation of Laminate <Backing Layer>
A foamed resin sheet (thickness: 2.4 mm, basis weight: 170 g/m ² , foaming ratio: 15 times) made of polyolefin resin was used.

<Adhesive resin>
A two-component polyurethane adhesive was used as the adhesive. The two components were mixed to create a mixture of 100 parts by weight of the main component, a polyol compound, and 25 parts by weight of an isocyanate compound. The viscosity of this mixture was 5 Pa·s. This two-component polyurethane adhesive resin (abbreviated as "PUA" in Tables 1 to 6) was applied to release paper using a gravure roll. The amount of adhesive resin applied was 41 g/ ^m² .

<Step of forming laminate>
The adhesive resin on the release paper was dried in a drying oven with the oven temperature controlled between 80°C and 100°C. The adhesive resin was then transferred to the backing layer, and the surface of the backing layer to which the adhesive resin had been transferred was placed on the half-cut surface of the skin layer. The laminate was then pressed at 80°C and 2 MPa for 60 seconds to cure the adhesive and form an adhesive resin. The resulting laminate had good color development and friction fastness in the skin layer, and maintained high surface quality even after press molding, while also achieving sufficient peel strength. The results are shown in Tables 1 and 2.

[Example 2]
A laminate was obtained in the same manner as in Example 1, except that (1) in the <Step of Forming a Fiber Structure> of Forming the Surface Layer, a fiber structure (short-fiber nonwoven fabric) with a fiber web thickness of 2.1 mm was used, but a fiber structure (short-fiber nonwoven fabric) with a fiber web thickness of 1.7 mm was used, resulting in an artificial leather with a thickness of 0.6 mm and a basis weight of 155 g/ ^m² , and (2) in the <Step of Forming a Laminate> of Forming the Laminate, the amount of adhesive resin applied was changed to 32 g/ ^m² . The obtained laminate had good color development and friction fastness of the surface layer, and maintained high surface quality even after press molding, while also achieving sufficient peel strength. The results are shown in Tables 1 and 2.

[Example 3]
A laminate was obtained in the same manner as in Example 1, except that (1) in the <Step of Forming a Fiber Structure> of Forming the Surface Layer, a fiber structure (short-fiber nonwoven fabric) with a fiber web thickness of 2.1 mm was used, but a fiber structure (short-fiber nonwoven fabric) with a fiber web thickness of 2.8 mm was used, resulting in an artificial leather with a thickness of 0.8 ^mm and a basis weight of 300 g/ ^m² , and (2) in the <Step of Forming a Laminate> of Forming the Laminate, the amount of adhesive resin applied was changed to 32 g/m². The obtained laminate had good color development and friction fastness of the surface layer, high surface quality even after press molding, and sufficient peel strength. The results are shown in Tables 1 and 2.

[Example 4]
A laminate was obtained in the same manner as in Example 1, except that (1) in the "step of polishing the sheet-like material" of forming the surface layer, sandpaper with a grit size of 180 was used, but sandpaper with a grit size of 100 was used to grind the artificial leather with a basis weight of 232 g/ ^m2 and a nap coverage of 70%, and further, in the "step of forming the laminate" of forming the laminate, the amount of adhesive resin applied was changed to 42 g/ ^m2 . Although the obtained laminate showed minor cracks in the bent portions after press molding, it had good color development and friction fastness of the surface layer and sufficient peel strength. The results are shown in Tables 1 and 2.

[Example 5]
(2) A laminate was obtained in the same manner as in Example 1, except that in forming the laminate, the backing layer was replaced with a polyester knit fabric (fineness 110T/48f, basis weight 340 g/ ^m2 , front structure 10/34, back structure 10/12) and the amount of adhesive resin applied in the laminate forming step was 40 g/ ^m2 . The obtained laminate had good color development and friction fastness in the surface layer, high surface quality even after press molding, and sufficient peel strength. The results are shown in Tables 1 and 2.

[Example 6]
A laminate was obtained in the same manner as in Example 1, except that in the (1) step of forming the surface layer (the step of applying the polycarbonate-based polyurethane), DMF solution S1 of polycarbonate-based polyurethane X was replaced with DMF solution S4 of polycarbonate-based polyurethane ^Y , resulting in an artificial leather with a basis weight of 218 g/m², and in the (2) step of forming the laminate (the step of forming the laminate), the amount of adhesive resin applied was changed to 41 g/ ^m² . The resulting laminate had slightly inferior peel strength, but the surface layer had good color development and friction fastness, and maintained high surface quality even after press molding. The results are shown in Tables 1 and 2.

[Example 7]
A laminate was obtained in the same manner as in Example 1, except that in (1) the step of forming an ultrafine fiber-developing fiber in the formation of the surface layer, P1 and P2 were used as island components, but P3 and P4 were used instead, resulting in an artificial leather with a basis weight of 192 g/ ^m² , and that in (2) the step of forming a laminate, the amount of adhesive resin applied was changed to 40 g/ ^m² . The obtained laminate had good color development and friction fastness in the surface layer, and maintained high surface quality even after press molding, while also achieving sufficient peel strength. The results are shown in Tables 3 and 4.

[Example 8]
A laminate was obtained in the same manner as in Example 1, except that in (1) the step of forming an ultrafine fiber-developing fiber in the formation of the surface layer, P1 and P2 were used as island components, but P1 and P5 were used instead, resulting in an artificial leather with a basis weight of 235 g/ ^m² , and that in (2) the step of forming a laminate, the amount of adhesive resin applied was changed to 40 g/ ^m² . The obtained laminate had good color development and friction fastness in the surface layer, and maintained high surface quality even after press molding, while also achieving sufficient peel strength. The results are shown in Tables 3 and 4.

[Example 9]
A laminate was obtained in the same manner as in Example 1, except that an artificial leather with a basis weight of 385 g/ ^m² was used, and the following step of forming a resin layer was added after the step of dyeing the greige leather in (1) forming the surface layer, and the amount of adhesive resin applied in the step of forming the laminate in (2) forming the laminate was 40 g/ ^m² . Although the obtained laminate showed minor cracks in the bent portions after press molding, it had good color development and friction fastness in the surface layer, and also had sufficient peel strength. The results are shown in Tables 3 and 4.

<Step of forming resin layer>
The first layer was made of a polyether-based polyurethane, and the second and third layers were made of a polycarbonate-based polyurethane. The rotary coating method was repeated three times on the nap-bearing side of the artificial leather to form three discontinuous polyurethane resin layers. The surface was dotted with islands of resin, with a nap coverage of 40% and a total thickness of 0.2 mm.

[Example 10]
(1) A laminate was obtained in the same manner as in Example 1, except that in the "process of dyeing the greige" for forming the surface layer, the dye concentration was increased to make the dye content in the artificial leather 7% by mass, and the basis weight was 225 g/ ^m² , and the amount of adhesive resin applied was 40 g/ ^m² . The obtained laminate had slightly inferior friction fastness, but had good color development in the surface layer, high surface quality even after press molding, and sufficient peel strength. The results are shown in Tables 3 and 4.

[Example 11]
(1) In the "step of applying polycarbonate-based polyurethane" for forming the surface layer, a laminate was obtained in the same manner as in Example 1, except that instead of using DMF solution S1 of polycarbonate-based polyurethane X, DMF solution ^S5 of polycarbonate-based polyurethane Y was used to create an artificial leather with a basis weight of 220 g/m². The resulting laminate had good color development and friction fastness in the surface layer, and maintained high surface quality even after press molding, while also achieving sufficient peel strength. The results are shown in Tables 3 and 4.

[Example 12]
(2) A laminate was obtained in the same manner as in Example 1, except that a polyolefin-based adhesive containing neither an isocyanate compound nor its reaction product was used as the adhesive in the formation of the laminate. The resulting laminate had sufficient peel strength, although it was slightly inferior to the other examples. In addition, the surface layer had good color development and friction fastness, and high surface quality even after press molding. The results are shown in Tables 3 and 4.

[Comparative Example 1]
A laminate was obtained in the same manner as in Example 1, except that (1) the <step of applying polycarbonate-based polyurethane> in forming the surface layer was replaced with the <step of applying polyurethane α> described below, and artificial leather with a basis weight of 208 g/ ^m² was used, and further, in (2) the <step of forming a laminate> in forming the laminate, the amount of adhesive resin applied was changed to 41 g/ ^m² . Although the obtained laminate had good color development and friction fastness in the surface layer, cracks were observed throughout the laminate even after press molding, and the laminate had poor peel strength from the backing material. The results are shown in Tables 5 and 6.

<Step of adding polyurethane α>
The sheet made of ultrafine fibers was immersed in a DMF solution S2 of polyurethane α, and then the sheet immersed in the DMF solution S2 of polyurethane α in an aqueous solution with a DMF concentration of 30% by mass was immersed in hot water at 90° C. to remove the DMF, thereby coagulating the polyurethane α. Thereafter, the sheet was dried with hot air at a temperature of 110° C. for 10 minutes, thereby obtaining a sheet-like material to which polyurethane α was imparted.

[Comparative Example 2]
A laminate was obtained in the same manner as in Example 1, except that (1) the <step of applying polycarbonate-based polyurethane> in forming the surface layer was replaced by the <step of applying polyurethane β> below, and artificial leather with a basis weight of 220 g/ ^m² was used, and further, in (2) the <step of forming a laminate> in forming the laminate, the amount of adhesive resin applied was changed to 40 g/ ^m² . The resulting laminate had good color development and friction fastness in the surface layer, but the texture of the surface layer was hard, and cracks were observed throughout even after press molding, resulting in a laminate with poor peel strength from the backing material. The results are shown in Tables 5 and 6.

<Step of adding polyurethane β>
The sheet made of the ultrafine fibers was immersed in a DMF solution S3 of polyurethane β, and then the sheet immersed in the DMF solution S3 of polyurethane α in an aqueous solution with a DMF concentration of 30% by mass was immersed in hot water at 90° C. to remove the DMF, thereby coagulating the polyurethane β. Thereafter, the sheet was dried with hot air at a temperature of 110° C. for 10 minutes, thereby obtaining a sheet-like material to which polyurethane β was imparted.

[Comparative Example 3]
A laminate was obtained in the same manner as in Example 1, except that in (1) the <Step of forming ultrafine fiber development> of forming the surface layer, P1 and P2 were used as island components, but only P1 was used; in (2) the <Step of dyeing the greige>, the dye concentration was increased to use an artificial leather with a dye content of 7 mass% and a basis weight of 210 g/ ^m2; and in (2) the <Step of forming the laminate> of forming the laminate, the amount of adhesive resin applied was changed to 42 g/ ^m2 . The obtained laminate had sufficient peel strength and no cracks were observed even after press molding, but the color development and color fastness of the surface layer and the surface quality after press molding were poor. The results are shown in Tables 5 and 6.

[Comparative Example 4]
(2) A laminate was obtained in the same manner as in Comparative Example 2, except that a polyolefin-based adhesive containing neither an isocyanate compound nor its reaction product was used as the adhesive in the formation of the laminate. The resulting laminate had good friction fastness in the surface layer, but the texture of the surface layer was hard, and cracks were observed throughout even after press molding, resulting in a laminate with poor peel strength from the backing material. The results are shown in Tables 5 and 6.

As shown in Tables 1 to 4, the laminates of Examples 1 to 12 contained black pigment in the ultrafine fibers of the skin layer, and by using two types of polycarbonate-based polyurethane with specific skeletons as the polyurethane in the skin layer, all of the laminates had good color development and friction resistance in the skin layer, while also achieving sufficient peel strength.

On the other hand, as shown in Tables 5 and 6, when polyurethane without polycarbonate in the skeleton was used for the polyurethane in the skin layer, as in the laminate of Comparative Example 1, crosslinking points with the adhesive resin were not formed, resulting in a laminate with poor peel strength from the backing material.

Furthermore, when only one type of polycarbonate-based polyurethane was used in the polyurethane skeleton of the skin layer, as in the laminates of Comparative Examples 2 and 4, the resulting skin layer was extremely rigid, and no crosslinking points were formed with the adhesive resin, resulting in a laminate with poor peel strength from the backing material.

Furthermore, when the ultrafine fibers do not contain a black pigment, as in the laminate of Comparative Example 3, the dye deteriorates when heated, causing a significant change in the hue of the ultrafine fibers, resulting in a laminate with poor color development and abrasion resistance in the surface layer after high-temperature press molding.

11: Laminate 12a: Ultrafine fiber 12b: Polycarbonate-based polyurethane 12c: Ultrafine fiber bundle 13: Backing layer 14: Adhesive resin 15: Boundary between backing layer and adhesive resin 16: Perpendicular line from the boundary between backing layer and adhesive resin to the interface of the adhesive resin on the skin layer side 17: Ultrafine fiber closest to backing layer 18: Perpendicular line from the boundary between backing layer and adhesive resin to the surface on the backing layer side 19: Perpendicular line from the ultrafine fiber closest to backing layer to the surface on the skin layer side 20: Boundary between adhesive resin and skin layer side 21: Floor surface 22: Inspection table 23: Laminate 24: Position for visual inspection 25: Line connecting the position for visual inspection and the laminate 26: Fluorescent light 27: Perpendicular line from the laminate to the fluorescent light

Claims (11)

A laminate comprising a surface layer containing artificial leather and a backing layer laminated together via an adhesive resin,
The artificial leather includes a fiber structure and a polycarbonate-based polyurethane,
the fiber structure includes ultrafine fibers made of a polyester resin containing a black pigment and/or a chromatic pigment,
The polycarbonate-based polyurethane has a skeleton represented by the following general formula (1) and a skeleton represented by the following general formula (2), or
It has a skeleton represented by general formula (2) and a skeleton represented by general formula (3),
The backing layer is at least one material selected from the group consisting of woven or knitted fabrics, nonwoven fabrics, and foamed resin sheets.
Laminate.
(In the formula, _R1 and _R2 are aliphatic hydrocarbon groups having 7 to 11 carbon atoms and may be the same or different. Furthermore, n and m are positive integers. When _R1 and _R2 are different, the copolymer is a block copolymer or a random copolymer.)
(In the formula, _R3 and _R4 are aliphatic hydrocarbon groups having 3 to 6 carbon atoms and may be the same or different. Furthermore, x and y are positive integers. When _R3 and _R4 are different, the copolymer is a block copolymer or a random copolymer.)
(In the formula, _R5 is an aliphatic hydrocarbon group having 3 to 5 carbon atoms, and _R6 is an aliphatic hydrocarbon group having 8 to 12 carbon atoms. Furthermore, a and b are positive integers, and _R5 and _R6 are block copolymers or random copolymers.) The laminate according to claim 1, wherein the adhesive resin is a polyurethane-based resin. The peel strength when the surface layer is peeled from the laminate is 7 N/cm or more and 16 N/cm or less,
The failure mode at the time of peeling is
cohesive failure of the adhesive resin,
a material failure of the backing layer;
Interfacial failure or mixed interfacial/cohesive failure between the adhesive resin and the backing layer;
The laminate according to claim 1 or 2, wherein The laminate described in claim 1 or 2, wherein the nap coverage of the surface layer is 70% or more and 100% or less. The laminate described in claim 1 or 2, having a resin layer on at least a portion of the surface of the skin layer. The laminate according to claim 1 or 2, wherein the dye content of the surface layer is 3% by mass or less. A method for producing the laminate according to claim 1 or 2,
A method for manufacturing a laminate, comprising the steps of applying an adhesive to one surface of sheet A which will become the backing layer, placing sheet B which will become the skin layer on the surface coated with the adhesive, and curing the adhesive to integrate sheet A and sheet B via an adhesive resin which is the cured product of the adhesive. The method for manufacturing a laminate according to claim 7, wherein the adhesive is a two-component polyurethane adhesive comprising an isocyanate compound and a polyol compound. An interior material comprising the laminate of claim 1 or 2. A vehicle part comprising the laminate of claim 1 or 2. Furniture comprising the laminate of claim 1 or 2.