JPH022992B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a leather-like sheet material that is extremely thin, flexible, has a moist feel in the hand, and has a skin layer that is strong and has excellent durability. Traditionally, so-called silver-type leather-like sheets with a skin layer have been made of synthetic leather, which is made by coating a base such as knitted or woven fabric with resin such as polyvinyl chloride, polyamide, or polyurethane. Ta. In such synthetic leathers, it is easy to manufacture thin sheets because the base material is knitted or woven, but these have a surface layer covered with a thick non-porous or porous resin. Because of this, the appearance is vinyl-like,
Alternatively, it had a strong rubbery texture and touch, was paper-like, and did not have a moist feel in the hand, making it a low-grade material for clothing. In order to improve these drawbacks, in recent years, non-woven structures using special ultrafine fibers have been made to contain resins mainly composed of elastic polymers as the base layer, and porous or non-woven structures made of urethane polymers etc. have been added to the base layer. Various studies have been conducted to obtain flexibility and an appearance similar to natural leather by laminating and integrating a porous layer, a porous layer and a non-porous layer, or two or more types of non-porous layers. It has been put into practical use as a material for some clothing. However, there are still artificial leathers for clothing that have an elegant appearance, are extremely thin (less than 0.5 mm thick), and have sufficient flexibility and durability. I haven't been able to get it. Conventional technology uses a composite structure in which resin is contained in a nonwoven structure as a base layer, so when considering its strength and texture, the amount of resin, the bonding state of resin and fibers, and the amount of resin are always considered. It was necessary to understand many factors, such as the microporous structure, and to consider the balance between strength and texture. For example, if the amount of resin is increased or the bond between the resin and the fibers is strengthened, sufficient strength can be obtained, but on the contrary, the material lacks flexibility. On the other hand, if the amount of resin is reduced too much in order to obtain flexibility, sufficient strength will not be obtained, and achieving both strength and texture (flexibility) is extremely difficult. It was hot. In particular, sheet materials made of non-woven structures
In order to obtain something that is thin and strong, less than 0.5 mm, it is necessary to increase the amount of resin, and as a result, the sheet material becomes hard and has a paper-like texture, and in the end, it becomes soft and durable. It was impossible to obtain a sheet-like product that had a smooth feel in the hand and was also excellent in durability. On the other hand, since a non-woven structure alone does not have sufficient strength as mentioned above, some attempts have been made to insert and integrate knitted or woven fabric into the non-woven structure to strengthen it;・When a woven fabric is inserted, compared to a single non-woven structure, it is easier to peel off at the interface between the knitted fabric and the knitted fabric, and the stitches of the knitted fabric tend to appear on the surface. It has drawbacks such as fraying, and these drawbacks become especially noticeable when the thickness of the sheet-like material is reduced, resulting in not only an inability to obtain an elegant appearance but also poor durability. It was hot. In addition, in conventional skin layer forming techniques, the skin layer is only a resin layer obtained by coating the base layer with a resin such as polyurethane, or is simply an integrated product of the fluff fibers on the surface of the base layer and the resin layer, so it is difficult to be easily rubbed. When shearing stress is repeated, cracks and fissures occur on the surface, and the surface becomes fluffy, and the durability of the skin layer is not sufficiently satisfactory. The purpose of the present invention is to fully take into consideration the problems of the conventional leather-like sheet material having a skin layer, and to create a material with a thickness of less than 0.5 mm, which was previously impossible to obtain, without the above-mentioned problems. An object of the present invention is to provide a leather-like sheet material having a skin layer that is thin, flexible, strong, and has good durability. This object of the present invention is achieved by the following configuration. That is, the leather-like sheet-like material of the present invention is a leather-like sheet-like material having a skin layer on at least one side, and the fiber structure constituting the sheet-like material is
Ultrafine fibers of 0.01 denier or less and/or bundles of these fibers are three-dimensionally entangled, and the skin layer is made of the ultrafine fibers and/or their bundles that are densely entangled with a distance between fiber entanglements of 200 microns or less. It is a composite of a bundle and a resin, and the apparent density of the fibers constituting the sheet-like material is 0.3 g/cm ³ or more, the sheet-like material has a thickness of less than 0.5 mm, and a tensile strength of 3 kg. /cm or more, and the leather-like sheet material is characterized in that there is substantially no resin other than the skin layer. The leather-like sheet material of the present invention has a skin layer that is
The fibrous structure that is formed as a composite of densely entangled ultrafine fibers and/or bundles thereof and resin and that constitutes the sheet-like article is made of ultrafine fibers of 0.01 denier or less and/or bundles thereof. It is a three-dimensional entangled body, and the apparent density of the fiber structure is
It is necessary to have a density of 0.3 g/cm ³ or more, and only by this combination can it be extremely thin, yet have a soft and moist feel in the hand.
It has now become possible to provide a leather-like sheet material having a skin layer that is strong and has excellent durability. As the ultrafine fibers used in the present invention, ultrafine fibers directly produced by methods such as super draw or melt blowing may be used, but if the fibers are as thin as 0.01 denier or less, spinning becomes unstable.
Since it is difficult to process and handle, it is preferable to use ultrafine fiber-forming fibers described below and convert them into ultrafine fibers at an appropriate time during the processing process. That is, the ultrafine fiber-forming fiber used in the present invention is, for example, a fiber made by converging ultrafine fibers immediately after spinning and lightly adhering them into a single fiber.
Fibers with a chrysanthemum-shaped cross section in which components are interposed radially between other components, multilayer bimetal fibers, multilayer bimetal fibers with donut-shaped cross sections, mixed spun fibers made by melt-mixing and spinning two or more components, fiber axial direction Polymer mutually arranged fibers are made of a large number of continuous ultra-fine fibers that are combined and/or partially combined with other components to form a single fiber, and two or more of these fibers are mixed or combined. It may also be used. Furthermore, when at least one component is dissolved and removed, a bundle of fibers consisting mainly of ultrafine fibers of 0.01 denier or less can be obtained.Ultrafine fiber-forming fibers made of other components, such as polymer mutual array fibers and mixed spun fibers, are suitable for It is possible to give a leather-like sheet-like material a space with a particularly supple texture,
It is most preferably used because it yields a leather-like sheet material with a smooth surface. Further, the ultrafine fibers in the present invention are made of polymeric substances having fiber-forming ability, such as nylon 6, nylon 66,
Polyamides such as nylon 12 and copolymerized nylon,
Examples include polyesters such as polyethylene terephthalate, copolymerized polyethylene terephthalate, polybutylene terephthalate, and copolymerized polybutylene terephthalate, polyolefins such as polyethylene and polypropylene, polyurethane, polyacrylonitrile, and vinyl polymers.
Further, as the binding component or the dissolving and removing component of the ultrafine fiber-forming fiber, for example, polystyrene,
Polyethylene, polypropylene, polyamide, polyurethane, copolymerized polyethylene terephthalate easily soluble in alkali solutions, polyvinyl alcohol, copolymerized polyvinyl alcohol, styrene-acrylonitrile copolymer, higher alcohol ester of styrene and acrylic acid and/or higher methacrylic acid Copolymers with alcohol esters are used. Polystyrene, styrene-acrylonitrile copolymers, and copolymers of styrene and higher alcohol esters of acrylic acid and/or higher alcohol esters of methacrylic acid are preferably used in terms of ease of spinning and ease of dissolution and removal. The fineness of the ultrafine fibers forming the nonwoven entangled structure of the present invention must be 0.01 denier or less.
If it is thicker than 0.01 denier, it is disadvantageous to sufficiently increase the intertwining density of the fibers. It is difficult to obtain sufficient strength to obtain a sheet-like product. Particularly when trying to obtain a very thin sheet-like product as in the present invention, it is essential to obtain a high entanglement density. By the way, in order to increase the entanglement density of fibers, not only the entanglement technique described below, but also the fineness of the fibers are greatly related.
The more fine fibers are used, the higher the intertwining density can be. In addition, if the fineness of the fibers constituting the skin layer using these microfibers is large, the rigidity of the fibers will be excessive, which will not only impair the flexibility of the skin layer and the form of wrinkles on the surface,
Cracks tend to occur when rubbed, making it difficult to form a dense and supple skin layer. By using ultrafine fibers of 0.01 denier or less, it is possible to greatly improve the intertwining density of fibers, and it also has sufficient strength and smoothness to create a skin layer that is difficult to crack. Furthermore, even without containing an elastic polymer for reinforcement in the base layer, it is extremely thin at less than 0.5 mm, and despite its thinness, it has flexibility, strength, and durability. It is also possible to obtain a leather-like sheet material with excellent properties. Regarding the nonwoven entangled structure of the leather-like sheet of the present invention, the ultrafine fibers of 0.01 denier or less and/or bundles thereof are three-dimensionally entangled, and at least in the skin layer of one side of the sheet. It is necessary that the ultrafine fibers and/or bundles thereof are intertwined with each other extremely densely. Here, one method to measure the fiber entanglement density is to measure the fiber entanglement point distance, which will be described later, but the fibers in at least one skin layer have an entanglement density of 200μ or less as measured by this method. It is necessary to do so. Structures where this value is greater than 200μ,
In other words, with conventional nonwoven structures in which the fibers are entangled only by needle punching,
As mentioned earlier, not only is it not possible to obtain sufficient strength with a nonwoven structure alone, but also a structure in which a skin layer is formed on the base using a resin-containing base of the nonwoven structure Since the skin layer has little or no entanglement of fibers, it also has the disadvantage that the surface becomes fluffy or cracks occur when subjected to abrasion, kneading, repeated shearing force, etc. In order to eliminate these drawbacks, form a smooth and durable skin layer, and obtain sufficient strength from the nonwoven entangled structure alone, the distance between fiber entanglement points must be 200μ or less. do. More favorable results can be obtained when the thickness is 100μ or less. In addition, if the distance between the intertwining points of both surface layers of the leather-like sheet is 200μ or less, the denseness of both sides will improve, so physical properties such as strength will improve, and a unique texture will be obtained. preferable. Furthermore, if the inner layer of the leather-like sheet material has such a dense structure, physical properties such as strength will be improved, which is preferable. Here, the distance between fiber entanglement points is a value obtained by the following method, and is a measure of the denseness of fiber entanglement, and the smaller the value, the more dense the entanglement. . The figure is an enlarged schematic view of the constituent fibers in the epidermis layer when observed from the surface side. _The constituent fibers are f ₁ , f ₂ , f ₃ ..., and the point where any two fibers f ₁ and f ₂ are intertwined is a _{1 .} Follow the fibers down to the point where they intersect and call that point a ₂ (intersection point of f ₂ and f ₃ ). Similarly, let a ₃ , a ₄ , a ₅ .... Next, the linear horizontal distances between the intersecting points obtained in this way a ₁ a ₂ , a ₂ a ₃ , a ₃ a ₄ ,
a ₄ a ₅ , a ₅ a ₆ , a ₆ a ₇ , a ₇ a ₃ , a ₃ a ₈ , a ₈ a ₇ , a ₇ a ₉ ,
a ₉ a ₆ . . . are measured, and the average value of these many measured values is determined, and this is taken as the distance between the fiber entanglement points. The apparent density of the fibers constituting the leather-like sheet material according to the present invention is required to be at least 0.3 g/cm ³ or more. When the density is 0.35 g/cm ³ or more, it is preferable because the leather-like sheet material has a more substantial feeling (moist feel in the hand). The apparent density of the fibers here refers to the thickness of the weight of the fibers per unit area of the sheet-like object measured using a thickness meter with a pressing load of 50 g/cm ² (the thickness of the sheet-like object in the present invention refers to all (represents the value measured with the thickness gauge). The apparent density of this fiber is 0.3
When it is less than g/ ^cm3 , only the surface layer of the sheet material is tightly entangled, but the fibers in the inner layer are hardly entangled or a structure with very little entanglement is prevented. hard. Sheet-like products with such a structure have creases caused by internal voids that remain on the skin layer, resulting in an ugly appearance, lack of a sense of fullness, and lack of a moist feel in the hand. If the sheet-like material is thin and has local density unevenness, it has the disadvantage that particularly the low-density portions may be visible. In order to eliminate these drawbacks, the apparent density of the fibers needs to be 0.3 g/cm ³ or more. In addition, the number of ultrafine fibers included in the bundle of ultrafine fibers forming the nonwoven entangled body does not need to be the same for all bundles, and the closer to the surface layer, the more It is preferable that the number of fibers is as small as possible, since unevenness is less likely to occur on the surface of the sheet-like article. Further, it is more preferable that the inner layer part has a structure in which the original ultrafine fiber bundle is branched and intertwined to reduce the number of fibers in the bundle, since a high intertwining density can be obtained. The resin used for forming the skin layer is, for example, polyamide, polyester, polyvinyl chloride, polyacrylic acid ester copolymer, polyurethane, neoprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polyamino acid, polyamino acid polyurethane, etc. These include polymers, synthetic resins such as silicone resins, natural polymer resins, and mixtures of these resins. Furthermore, if necessary, plasticizers, fillers, stabilizers, pigments, dyes, crosslinking agents, etc. may be added. Polyurethane resins or polyurethane resins to which other resins and additives are added are preferably used because they provide a skin layer that has a particularly soft texture and touch and has good bending resistance. The leather-like sheet material of the present invention thus obtained must have a tensile strength of 3 kg/cm or more.
It is more preferable if it is 4Kg/cm or more. This value is 3
If it is less than Kg/cm, the durability is poor and, for example, when used as a material for clothing, it is undesirable because it causes the elbows to come off, the knees to come off, the buttocks to wear out, and the seams torn. The leather-like sheet material of the present invention can be produced, for example, by the following novel method. First, the ultrafine fiber-forming fibers, for example,
It is produced using the spinning apparatus shown in Japanese Patent No. 18369, stapled, passed through a card and a cross wrapper to form a web, and then needle punched to intertwine the ultrafine fiber-forming fibers to form a fiber sheet. Alternatively, following the spinning of the microfiber-forming fibers, they are stretched and placed randomly on a wire mesh, and the obtained web is needle punched in the same manner as described above to form a fiber sheet. At this time, according to conventional knowledge, one way to obtain ultra-thin objects with a thickness of less than 0.5 mm is to reduce the web weight, but with that method, the web tends to stretch during needle punching.
It is difficult to form a fiber sheet. In addition, after increasing the basis weight and forming a fiber sheet with a normal thickness,
Although slicing to a desired thickness using a slicer may be considered, in such a method, fibers arranged in a direction perpendicular to the fiber sheet surface are cut, which further reduces entanglement of the fiber sheet. For this reason, it has traditionally been impossible to manufacture thin, flexible, strong and durable sheet-like products, but for example, by using a new method as shown below, it is possible to reduce the entanglement density of fibers even though they are extremely thin. It becomes possible to increase the That is, the surface of the fiber sheet thus obtained is brought into contact with a high-speed fluid flow to branch or fibrillate at least the surface layer of the fiber sheet into ultrafine fibers and/or bundles thereof, and at the same time to entangle them densely. The fluid referred to here is a liquid or a gas, and in special cases it may contain extremely fine solids, but water is the most suitable in terms of ease of handling, cost, and amount of collision energy as a fluid. Preferably used. These fluids are pressurized and injected from small-diameter nozzles or narrowly spaced slits to form a high-speed columnar flow or curtain-like flow, which is brought into contact with the fiber sheet to branch or fibrillate and entangle the fibers. The pressure applied to the liquid varies depending on the ease of branching or fibrillation of the ultrafine fiber-forming fiber or ultrafine fiber bundle, and for fibers that are easily branched or fibrillated, a relatively low pressure of 5 to 100 kg/cm ² may be sufficient. However, for fibers that are difficult to branch, 100 to 300
High pressures of Kg/cm ² are preferred. It is also possible to increase the degree of branching, fibrillation, and entanglement by increasing the number of times of contact, and the pressure may be changed each time of contact. Dense entanglement to the inside of the fiber sheet depends on the degree of initial entanglement and apparent density of the sheet by needle punching, the number of times of contact with high-speed fluid flow, the diameter of the nozzle, the nozzle discharge pressure, etc., so it cannot be said with certainty. However, it is preferable to increase the nozzle pressure or increase the nozzle diameter because the action of the high-speed fluid flow can easily extend to the inside of the sheet, and the inside of the sheet can be entangled closely. Thereafter, the fiber entangled sheet is subjected to a shrinkage treatment. At this time, it is necessary to apply strong compression in the thickness direction using a heating roll to further increase the density of the tightly entangled fiber sheet. The shrinkage treatment may be performed before the fiber sheet is treated with a high-velocity fluid stream,
If this is done before treatment, the density of the fiber sheet will become too high, and only the surface layer of the sheet will be particularly densely entangled, making it difficult for the action of the high-speed fluid flow to reach the inside of the sheet. After that, it is preferable to perform shrinkage/strong compression treatment because it is possible to intertwine the sheets densely to the inside of the sheet. In particular, in order to realize a sheet-like product with a thickness of less than 0.5 mm and an apparent density of 0.3 g/ ^cm3 or more, it is necessary to It is important to perform a process that applies a strong compression effect. In this case, if a highly shrinkable fiber made of adipic acid or isophthalic acid copolymerized polyethylene terephthalate, or a binary or ternary copolymer of nylon 6, 66, or 610 is used as the ultrafine fiber, the fiber sheet can be further improved. This is preferable because the density can be increased. Thereafter, if necessary to make the ultrafine fiber-forming fibers used ultrafine, the resulting fiber sheet is treated with a solvent that dissolves at least one component of the ultrafine fiber-forming fibers, and Dissolve and remove components. Here, the one component may be dissolved and removed before the treatment with the high-speed fluid flow, and in this case, by dissolving and removing the one component, the ultrafine fiber-forming fibers of the fiber sheet become bundles of ultrafine fibers. This is a preferred method because it is metamorphosed and can be easily and highly branched and entangled at low fluid pressures. Further, high-speed fluid flow treatment may be performed before and after the step of dissolving and removing the one component. After that,
A solution or dispersion of the skin layer resin described above is applied to the surface layer part of the obtained fiber entangled sheet where the ultrafine fibers and/or their bundles are particularly densely entangled, by reverse roll coating, gravure coating, knife coating, slit coating, It is applied by a method such as spraying, solidified by a wet or dry method, stacked on the roll surface or sheet surface, pressurized, and heated as necessary to integrate the fiber and resin and at the same time smooth the surface. Let's do it. Here, it is also a preferable method to subject the fiber sheet to a treatment such as pressing to smooth the surface before applying the resin. At this time, it is preferable to use an emboss roll or a textured sheet with a textured pattern on the surface because integration, smoothing, and texture formation can be performed at the same time. Further, the step of dissolving and removing one component of the microfiber-forming fiber may be performed after the skin layer is formed. Furthermore, a thin film made of resin may be formed on the skin layer as long as the object of the present invention is not impaired. After that, treatments such as applying a finishing agent, dyeing, and rolling are performed as necessary. The leather-like sheet material of the present invention has a fiber structure consisting of a three-dimensional entangled body of specific ultrafine fibers and/or bundles thereof, and the skin layer is composed of extremely dense entangled points of such fibers and resin. It is a complex with
Moreover, because it has the apparent density and tensile strength of specific fibers, it feels flexible and moist in the hand even though it is extremely thin (less than 0.5 mm), has a smooth surface feel, and is strong and resistant to bending. It also has excellent durability such as shear fatigue resistance and scratch resistance. Furthermore, the leather-like sheet material of the present invention is comfortable even when worn directly on the bare skin and can be worn even in early summer, so it is particularly suitable for casual wear such as dresses, skirts, blouses, and pants that have rich drape properties. It is something. The examples shown below are for the purpose of clarifying the present invention, and the present invention is not limited thereto. In the examples, parts and percentages are by weight unless otherwise specified. Moreover, the value of the average intercrossing point distance was taken as the average value of 100 measured values. Example 1 A vinyl polymer (hereinafter referred to as AS resin) copolymerized with 20 parts of 2-ethylhexyl acrylate and 80 parts of styrene was used as a bonding component, and nylon 6 was used as a microfiber component in a ratio of 33 parts. 1977-- which has 12 island components in the filament and further contains many ultrafine fiber components with an average single denier of 0.002.
of polymeric interarray fibers as shown in 37648.
Cards using 3.5 denier, 51mm staples,
A web was formed through a cross wrapper, and then needle punched using a needle with one hook to intertwine the fibers of the polymeric interlayer arrangement to produce a nonwoven fabric. The basis weight of the non-woven fabric is 640g/m ² ,
The apparent density was 0.22 g/cm ³ . Next, the nonwoven fabric was cut in half with a slicer so that the thickness was divided into two to create fiber sheets (A) and (B). The thickness of the fiber sheet (A) is 1.45 mm, and the basis weight is 318 g/m ² .
The density was 0.219 g/cm ³ . On the other hand, the fiber sheet (B) had a thickness of 1.44 mm, a basis weight of 321 g/m ² , and a density of 0.223 g/cm ³ . Next, water with a pressure of 100 kg/cm ² is applied to both sides of the fiber sheet (A) while vibrating the nozzle from a nozzle in which holes with a diameter of 0.25 mm are arranged in a row with a distance of 0.6 mm between the centers of the holes. It was injected at high speed four times under the same conditions. Next, the fiber sheet (A) is immersed in hot water at 85°C to shrink by about 30% in area, and is strongly nipped with heating rolls at 0.3t (t represents the sheet thickness before shrinkage) for strong compression. After adding in the thickness direction,
Dry. On the other hand, after shrinking the fiber sheet (B) at 85℃, the pore size
Pressure 100 using 0.1mm, pitch 0.6mm nozzle
Kg/cm ² , the surface corresponding to the sliced side was treated with a high-speed fluid flow while vibrating the nozzle four times (no strong compression treatment). Next, a 12% solution of polyurethane was applied to the surfaces corresponding to the sliced surfaces of the fiber sheets (A) and (B) at a solid content of 5 g/
It was applied with a gravure coater so that it was ² m2. After that, it is pressed through a heated embossing roll to emboss a leather-like chipo pattern, dipped in trichlorethylene, and repeatedly immersed and squeezed, resulting in almost complete AS.
The resin was extracted and removed. Furthermore, it was dyed using a jet dyeing machine under normal pressure, and finishing processing was performed using a conventional method. Table 1 shows the properties of the sheet-like product thus obtained. The leather-like sheet material obtained from the fiber sheet (A) has a smooth appearance with a textured pattern, and although it is extremely thin and flexible, it feels moist in the hand (feeling of fullness). It had the following characteristics. On the other hand, the leather-like sheet material obtained from the fiber sheet (B) had creases that were thought to be caused by internal voids remaining in the skin layer, making it somewhat ugly. In addition, the texture lacked a sense of fulfillment and had a dull feel. Furthermore, when these sheet-like materials were worn with slacks, the slacks made of the fiber sheet (B) were torn at the buttock seam after one week of wearing, and some parts of the buttocks were transparent. On the other hand, the slacks made of the fiber sheet (A) did not tear even after being worn for one month, and had excellent durability. When the cross-sectional structure of these sheet-like materials was observed using a scanning electron microscope, it was found that the fiber sheet (A) had a structure in which ultrafine fibers and/or bundles thereof were densely intertwined up to the inner layer of the sheet-like material. However, in the case of the fiber sheet (B), only the outermost layer was densely intertwined, but the inner layer had many voids in which only ultrafine fiber bundles were slightly intertwined.

[Table] Evaluated.
Example 2 Using a spinning device for forming multicomponent fibers equipped with a static mixer, isophthalic acid copolymerized polyethylene terephthalate was used as an ultrafine fiber component (island component).
40 parts AS resin used in Example 1 as binding component
By spinning at a ratio of 60 parts, ultrafine fiber-forming fibers containing about 700 ultrafine fibers with an average single filament fineness of 0.002 denier in one filament were obtained. After the fibers were drawn and crimped, they were cut to obtain staples with a fiber length of 51 mm. Next, a web was formed by passing it through a card cloth wrapper, and then punched using a needle with one hook to obtain a nonwoven fabric. The basis weight of this nonwoven fabric is 450g/m ² and the density is
It was 0.26g/ ^m2 . After that, it is sliced to adjust the thickness to a thickness of 0.93 mm, a basis weight of 241 g/m ² , and a density.
A sheet of 0.26 g/m ² was obtained. Next, using a nozzle with a hole diameter of 0.20 mm and a pitch of 0.5 mm, a high-speed fluid stream was injected at a pressure of 100 Kg/cm ² six times each on both sides of the sheet while the nozzle was vibrated. After that, the sheet was pre-shrinked in hot water at 60°C, then immersed in hot water at 80°C, and the sheet was shrunk by 45% in area through a two-stage stringing process, and then heated with strong nips using heating rolls. (strongly compressed) and dried. The thickness of the obtained fiber entangled sheet is 0.63
mm, basis weight was 438 g/m ² , and density was 0.70 g/cm ³ .
Further, the surface layer of the sheet was densely intertwined with fine microfibers and/or bundles thereof, and the distance between the intertwining points of the fibers was measured to be 11μ. Next, after smoothing the surface corresponding to the original sliced surface with a heating roll, a 15% solution of black pigment added to polyester polyurethane was mixed with a solid content of 3.
g/m ² was applied to the smoothed surface. Next, it was pressed through a heated embossing roll to emboss a leather-like grain pattern, and the AS resin was extracted and removed using a liquid jet extractor using trichlorethylene as a solvent. Furthermore, pressure dyeing was carried out at 120°C using a jet dyeing machine, and finishing processing was performed in the usual manner. The leather-like sheet material obtained in this way has a thickness of
Despite being extremely thin at 0.35mm, it felt moist and heavy, and had a texture that seemed to stick to the hand. In addition, the exterior had a luxurious feel similar to natural calf, and the back surface had a good texture. When I made it into a soft blouson, it felt comfortable even when worn against bare skin, and didn't feel stiff at all.
Even after wearing it for two weeks, I didn't have any problems with the elbow coming out. Furthermore, when the properties of this sheet-like material were evaluated, the basis weight was 178 g/m ² , the density was 0.51 g/cm ³ , the apparent fiber density was 0.50 g/cm ³ , and the tensile strength was 6.0 Kg/cm
It was hot.

[Brief explanation of drawings]

The figure is an enlarged schematic view of the constituent fibers in the epidermis layer when observed from the surface side. In the figure, f ₁ , f ₂ , f ₃ , f ₄ , f ₅ and f ₆ are the constituent fibers, and a ₁ , a ₂ , c ₃ , a ₄ , a ₅ , a ₆ , a ₇ , a ₈ and a ₉ are the constituent fibers. The intertwining points of the constituent fibers are shown.

Claims (1)

[Claims] 1. In a leather-like sheet material having a skin layer on at least one side, the fiber structure constituting the sheet material is a three-dimensional entanglement of ultrafine fibers of 0.01 denier or less and/or bundles thereof. and the skin layer is a composite of the ultrafine fibers and/or bundles thereof densely intertwined with a distance between fiber entanglement points of 200 microns or less and a resin, and the sheet-like material is The apparent density of the fiber is 0.3g/ ^cm3
In the above, the sheet-like article is a leather-like sheet-like article having a thickness of less than 0.5 mm, a tensile strength of 3 kg/cm or more, and substantially no resin other than the skin layer. . 2. The leather-like sheet material according to claim 1, wherein the fibers constituting the leather-like sheet material have an apparent density of 0.35 g/cm ³ or more. 3. The method according to claim 1 or 2, characterized in that the ultrafine fibers and/or bundles thereof are obtained by dissolving and removing one component from polymeric mutual array fibers. Leather-like sheet material. 4. The leather-like sheet according to claim 1 or 2, wherein the ultrafine fibers and/or bundles thereof are obtained by dissolving and removing one component from mixed spun fibers. something like that.