JP2003138489A - Artificial leather having excellent stretchability and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an artificial leather having a casual appearance developed by a streak crease pattern formed by a fine buckled structure in spite of the stretchability of the leather in contrast with a conventional artificial leather having a stretchable plain surface structure. SOLUTION: The artificial leather having excellent stretchability is a sheet produced by applying a polymer elastomer to an entangled fine fibers and/or fine fiber bundles. The sheet is imparted with a fine buckling structure in the longitudinal direction of the sheet and an essentially streak crease pattern in the lateral direction and has an elongation of >=10% and a stretch recovery of >=85% at least in the longitudinal direction. The method for the production of the artificial leather having excellent stretchability comprises the application of a polymer elastomer to entangled fine fibers and/or fine fiber bundles, the stuffing of the obtained sheet continuously in longitudinal direction to an extent to get a buckling number of >=5/ in under heating at >=50 deg.C and <=180 deg.C to form a buckled structure and taking the stuffed cloth out of the stuffing box.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an artificial leather having a peculiar appearance and excellent in stretchability, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a method for producing an artificial leather having excellent elasticity, as described in JP-A-48-18579, a non-elastic fiber and an elastic fiber mainly composed of polyurethane are mixed or laminated. And a method for producing a non-woven fabric structure, and JP-B-40-2792 and JP-A-61-4174.
No. 2, Japanese Patent Publication No. 1-41742, Japanese Patent Laid-Open No. 5-3
In Japanese Patent Publication No. 39863, a non-woven fabric is formed by using ultrafine non-elastic fibers and ultrafine elastic fibers composed mainly of polyurethane alone or using a composite fiber having the same island component, and removing the sea component in the composite fiber to form an ultrafine non-woven fabric. A method is disclosed in which a structure composed of elastic fibers and ultrafine elastic fibers is formed, and then a part of the elastic fibers is melted or glued.

Ultrafine elastic fibers are indispensable in any of the technologies, and therefore, they are difficult to be colored, and when heated, the ultrafine elastic fibers adhere to the ultrafine inelastic fibers to harden the texture, and only a plain surface appearance is obtained. Absent.

Further, Japanese Patent Laid-Open No. 62-110990,
Japanese Unexamined Patent Publication No. 7-145569 describes a method of applying a solution of an elastic polymer as a nonwoven fabric by mixing or laminating polyester fibers having different shrinkage rates and crystallinity, but flexibility and smoothness are described. However, it is difficult to obtain sufficient stretchability because the entangled body is fixed by the fiber having a high shrinkage ratio, and only a plain surface appearance can be obtained.

Further, in Japanese Patent Application No. 11-106843, a sheet obtained by applying polyurethane to a non-woven fabric composed of ultrafine fibers is subjected to hot water treatment with a jet dyeing machine to give a dyeing temperature of +3.
Although a method of dry heat treatment at 0 ° C. and then dyeing is disclosed, although some stretchability is obtained, only a surface appearance is also obtained.

On the other hand, as the wrinkle processing for making the surface have a different appearance, for example, the amount of raw machinery to be packed in a jet dyeing machine is put in an extremely larger amount than usual, and the time for staying in high temperature and humidity is increased to make the wrinkle disappear. Although there is a method of expressing the wrinkles, it is difficult to obtain a product having a rough wrinkle state and elasticity.

As described above, the conventional technology is a technology for imparting elasticity by utilizing the characteristics of fibers. Therefore, even if elasticity is obtained, the product surface only has a plain appearance,
No casual-like artificial leather has been developed yet, which produces fine wrinkles and unevenness.

[0008]

DISCLOSURE OF THE INVENTION The present invention is not a conventional plain surface appearance having stretchability, but a casual-like artificial appearance that produces a line-shaped wrinkle pattern due to a fine buckling structure while having stretchability. To provide leather.

[0009]

The present inventors have finally arrived at the present invention as a result of intensive studies to solve the above-mentioned problems.

The gist of the present invention is as follows.

That is, the artificial leather of the present invention is a sheet in which a polymer elastic material is provided to an entangled body of ultrafine fibers and / or ultrafine fiber bundles, and a fine buckling structure is provided in the longitudinal direction of the sheet. An artificial material having excellent stretchability characterized by having a substantially wrinkle pattern in the width direction and having an elongation rate of 10% or more and an elongation recovery rate of 85% or more in at least the length direction. Further, in the method for producing artificial leather of the present invention, a sheet in which a polymeric elastic body is applied to an entangled body of ultrafine fibers and / or ultrafine fiber bundles is used at 50 ° C. or higher.
While heating at 80 ° C or lower, it is continuously packed in the length direction so that the number of bucklings is 5 peaks / in or more, formed after buckling, and then taken out. It is a method of manufacturing leather.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below.

The artificial leather of the present invention is different from the conventional artificial leather provided with elasticity in which elastic fibers, stretchable fabrics and the like are combined, and is characterized in that it is an entangled body of ultrafine fibers and / or ultrafine fiber bundles. A fine buckling structure is provided in the length direction of the sheet to which the polymer elastic body is applied, and the sheet has a substantially wrinkle pattern in the width direction, and at least the elongation rate in the length direction is 10%. As described above, the elongation recovery rate is 85% or more, and the artificial leather has excellent elasticity.

Examples of the entangled polymer forming the ultrafine fibers and / or the ultrafine fiber bundles used in the present invention include polyamides such as nylon 6, nylon 66, nylon 12, copolymer nylon, polyethylene terephthalate, copolymer polyethylene terephthalate, Examples thereof include polybutylene terephthalate or copolymers thereof, polypropylene terephthalate or copolymers thereof, polylactic acid or copolymers thereof, and the like.

Among them, polypropylene terephthalate and copolymers thereof are preferably used from the viewpoints of elasticity, flexibility and nap properties. Polypropylene terephthalate is a polyester obtained by using terephthalic acid as a main acid component and 1,3 propanediol as a main glycol component. However, it may contain another copolymerizable component capable of forming an ester bond in a proportion of 20 mol%, more preferably 10% or less.

In this case, examples of the copolymerizable compound include dicarboxylic acids such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid and sebacic acid, while the glycol component includes ethylene glycol, for example. Examples thereof include, but are not limited to, diethylene glycol, butanediol, neopentyl glycol, cyclohexanedimethanol, polyethylene glycol, polypropylene glycol and the like.

The intrinsic viscosity of polypropylene terephthalate is preferably 0.5 or more and 1.2 or less. If it is less than 0.5, unevenness in fineness and yarn breakage during spinning are likely to occur, and if it exceeds 1.2, the melt viscosity is too high and the spinnability deteriorates. A more preferable intrinsic viscosity of PPT is 0.
It is 8 or more and 1.0 or less.

As the cross-sectional shape, a bimetal type, an eccentric type in which one component is exposed, and the like are preferably used in order to exhibit stretchability. Light-proofing agents for these polymers,
It may contain additives such as pigments, matting agents, antistatic agents, flame retardants and the like.

These ultrafine fibers may be directly spun monofilaments or may be obtained from multicomponent bicomponent fibers. In the case of a conjugate fiber, the above-mentioned fiber-forming polymer and a polymer having different solvent solubilities are combined, and at least one component is dissolved and removed or a method of physically and mechanically peeling or combining a divisible polymer is appropriately selected. Can be used.

The thickness of the ultrafine fibers is 1.1 dtex or less, preferably 0.5, from the viewpoint of the fine buckling structure forming property of the ultrafine fibers, the surface touch of the final product, the flexibility and the like.
It is preferably 5 dtex or less, more preferably 0.11 dtex or less. The cross-sectional shape of these fibers is not particularly limited.

In the present invention, a sheet in which a polymer elastic material is added to an entangled body of ultrafine fibers and / or ultrafine fiber bundles means
It means all the structures to which a polymer elastic body is added to a structure such as a non-woven fabric, a woven fabric or a knitted fabric in which ultrafine fibers and / or ultrafine fiber bundles are formed from short fibers or long fibers.

In order to enhance the surface appearance of the final product, it is preferable that at least one surface of this sheet has naps or a silver surface. The method for forming naps is not particularly limited, and for example, it can be easily formed by using surface grinding with sandpaper, which is commonly used in a method for manufacturing napped artificial leather, and nap treatment using a needle cloth. I can. Further, the method for forming with silver is not particularly limited, and for example, a resin is applied to the smoothed sheet surface with a gravure coater, a knife coater or the like which is commonly used in the method for producing artificial leather with silver, and a dry or wet method is used. It can be obtained by solidifying by a method.

For example, in the case of a non-woven fabric structure, the short fibers of the above-mentioned single fibers or composite fibers are used to form a web by using a card cloth wrapper or a random webber.
Entanglement treatment is performed using a needle punch, water jet punch, or a combination thereof, and if necessary, shrink treatment, sizing agent addition, and ultrafine treatment are combined, and a polymer elastic body is attached to this entangled body. Then, by coagulating the polymer elastic material by a dry method or a wet method, a sheet in which the polymer elastic material is applied to the entangled body of the ultrafine fibers and / or the ultrafine fiber bundle used in the present invention can be obtained.

Examples of the polymer elastic material include polyurethane elastic materials, acrylic-butadiene copolymers, styrene-butadiene copolymers, polybutadiene, and synthetic rubbers such as neoprene, and the like. From the viewpoint of compatibility and the like, a polyurethane elastic body is preferably used.

As the polyurethane elastic body, one containing at least one kind of polymer diol selected from polyester diol, polyether diol, polycarbonate diol and the like having an average molecular weight of 500 to 3000 is preferable, and among them, the strength of the product, abrasion resistance, etc. From the viewpoint of long-term durability, 30% by weight or more of polycarbonate diol is used.
Polyurethanes comprising polymeric diols up to and including wt.% Are particularly preferred. If it is less than 30% by weight, the fine crimp-forming property under heating as described later is low, and the durability of the physical properties of the product is insufficient. If it exceeds 90% by weight, the texture of the product becomes hard, which is not preferable in some cases.

Further, if necessary, additives such as colorants, antioxidants, antistatic agents, dispersants, softeners, coagulation regulators, flame retardants, antibacterial agents and deodorants are added to the above-mentioned elastic polymer. May be blended in the elastic polymer.

The amount of the polymeric elastic material cannot be generally determined depending on the form of the ultrafine fibers, the structure of the entangled body, etc., but considering the product texture and physical properties, it is preferably 5 to 70% by weight per fiber, Is preferably 10 to 50% by weight. If the amount is less than 5% by weight, the elasticity and flexibility are good, but the elongation recovery rate and the durability of the product are lowered. If the amount is more than 70% by weight, the fine crimp forming property under heating described later becomes low, The elongation rate tends to decrease.

A polymer provided with the polymer elastic material used in the present invention
The basis weight is 400 g / m²Below, preferably 1
00-300g / m² Is good. 2 mm or less
Lower, preferably 1 mm or less. Deviate from this range
With a fine buckling structure, it is difficult to form streak wrinkles and
Long-term rate tends to decrease. Also, as the lower limit, sheet formation is possible
Noble weight and thickness are the limits, but if both are too low, the wind
It's a paper-like match, and it's too buckling, so I like it.
It may not be necessary, and as a guideline, the basis weight is 60 g / m ² , Thick
Only about 0.2 mm.

The above-mentioned sheet does not impair the effect of the present invention even if the sheet penetrates in the thickness direction of the sheet and is subjected to the discontinuous perforation processing in the plane direction, and further enhances the elasticity. It may be preferable for The shape of the hole is not particularly limited, such as a circle, a rhombus, a triangle, and an ellipse.

In the present invention, by using the above-mentioned sheet, for example, a metal nip roll of a crimper device used for imparting crimps to fibers is widened and extruded while sandwiching the sheet while the nip roll rotates. The roll exit is fed into an adjustable stuffing box, the pressure at the stuffing box exit is adjusted to a predetermined pressure, and the continuously buckled sheet is discharged. Alternatively, a tension-controlled sheet is placed on the surface of the rotating drum and transferred, and the tip of a flat plate fixed near the apex of the rotating drum is pressed with a predetermined pressure to generate shear stress on the front and back of the sheet, while maintaining a predetermined gap. It is also possible to recommend a method of continuously pushing into.

By using such a method, a fine buckling structure is provided in the length direction of the sheet, and it becomes possible to form a substantially wrinkle pattern in the width direction.

The term "fine buckling structure in the lengthwise direction" as used herein means a structure in which a crimped state having W-shaped peaks and valleys is provided in the lengthwise direction of the sheet, and the peak portion or the peak portion forming the buckling is formed. The troughs suggest a structure in which the sheet is not necessarily continuous in the lateral direction of the sheet but also has a discontinuous state of irregular length.

The wrinkle pattern substantially in the horizontal direction of the sheet refers to the surface of the sheet which has been subjected to the above-mentioned bending process, and the concave portions formed by the valley portions in the horizontal direction are continuous or continuous. It suggests a pattern in which linear or curved stripes are formed discontinuously.

The artificial leather of the present invention has at least 10% elongation in the longitudinal direction while having the above-mentioned surface product having a different appearance.
As described above, the artificial leather is characterized by having an elongation recovery rate of 85% or more. In order to impart the elongation ratio and elongation recovery ratio related to the elasticity, it is important to heat the sheet to be continuously pushed in the above-described buckling formation method.

As a heating method, non-contact heating in dry heat or wet heat, a method of heating by contacting the surface of a heating roll, a method of permeating hot water immediately before being sandwiched by a metal nip roll, and the like are used. It is possible and may be appropriately selected depending on the sheet structure. In order to obtain the artificial leather of the present invention, the temperature of the above-mentioned sheet is 50 ° C or more and 180 ° C or less, preferably 80 ° C to 150 ° C. If the temperature is lower than 50 ° C., it is difficult to apply fine crimps, and the setability of the structure formed by buckling deteriorates. On the other hand, when the temperature exceeds 180 ° C., the long-term durability of the polymer elastic body is liable to be lowered, the settability is improved, and the texture is apt to be hard.

In order to enhance the elasticity, the number of bucklings of the buckled sheet is important, and the buckling-treated sheet is placed on a flat surface in a free state without applying a load, and the buckling number Measure the number of bucklings. Although it cannot be unconditionally limited because it depends on the properties such as the basis weight and thickness of the sheet, it is preferably 5 peaks / in or more, preferably 10 peaks / in or more.
When the buckling number is less than 5 peaks / in, it is difficult to obtain sufficient elasticity. The larger the number of bucklings, the more preferable, but this kind of buckling has a limit from the viewpoint of the mechanical mechanism, and the upper limit is about 40 peaks / in.

In order to impart the texture, surface touch, functionality, etc. of the product, the processed sheet is made to contain a softening agent, antistatic agent, flame retardant, antibacterial agent, deodorant, water repellent, etc. in advance. Is also good.

The sheet to be used in the buckling structure forming device may be dyed in advance, and dyeing after forming the buckling structure does not impair the effects of the present invention, and the final product. It is preferable to increase the added value of.

As described above, the stretchable artificial leather of the present invention is different from the conventional plain surface appearance, and as a napped or silver-finished artificial leather, the stretchable appearance is extremely varied in terms of product appearance. It will be excellent.

[0040]

EXAMPLES The present invention will be described in detail below with reference to examples.

The elongation rate and elongation recovery rate in the examples are measured by the following methods. <Intrinsic viscosity> 10 ml of orthochlorophenol,
0.1 g of the sample was dissolved and measured at 25 ° C. using an Ostwald viscometer. <Expansion rate> 5 cm x about 30 cm sample in the length direction,
Three samples each in the width direction, using a constant-speed extension type tensile tester, with a gripping interval of 20 cm, pulling speed 20c
It is stretched to 1.8 kg at m / min, the gripping interval at that time is measured, and the elongation rate (%) is calculated by the following formula, and the average value of three sheets is shown.

Elongation rate (%) = (L1−L) / L × 100 L: Gripping distance L1: Gripping distance when stretched to 1.8 kg <Elongation recovery rate> A sample of 5 cm × about 30 cm was stretched in the longitudinal direction. Three pieces each were taken in the width direction, a constant-speed extension type tensile tester was used to set the gripping interval to 20 cm, and then extended to 80% of the extension rate separately obtained by the above method, and allowed to stand for 1 minute, Return to the original position at the same speed and leave for 3 minutes. After repeating this operation 5 times, the elongation when stretched to a load equivalent to the weight of the sample is repeated 5 times and the residual elongation after elongation is obtained, and the elongation recovery rate (%) is calculated by the following formula, and the average of 3 sheets is calculated. Represents a value.

Elongation recovery rate (%) = (L2−L3) / L2 × 100 L2: Length on chart corresponding to elongation of 80% of elongation rate L3: Chart corresponding to residual elongation after 5 times of extension Above length Example 1 As a sea-island type polymer mutual array fiber, the island component has an intrinsic viscosity of 0.71 polyethylene terephthalate, the sea component is polystyrene, and the island / sea component ratio = 60/40 wt%, cut length A staple provided with a crimp of 51 mm, a composite fineness of 3.5 dtex, and 36 islands was prepared.

The staple was passed through a card / cross wrapper to form a web, which was then needle punched and felted. Next, this felt was subjected to shrinkage treatment in boiling water and dried with hot air. Polyvinyl alcohol was applied to the shrink felt and dried, and then the sea component was dissolved and removed with trichlorethylene and dried. Then, the polyester-polyether-based polyurethane solution diluted with DMF was added to the ultrafine-treated sheet in an amount of 28 per microfiber.
After being wet-solidified, the product was washed with hot water and dried.

The sheet was half-cut (sliced) in the thickness direction, and the non-half-cut surface was raised with sandpaper to obtain a raw fabric having a basis weight of 170 g / m ² .

Using a circular dyeing machine, this greige was
It was dyed brownish with a disperse dye at 25 ° C., a finishing agent was applied, and a drying treatment was performed. Then, using a Microcreper device (manufactured by USAMICREX Corporation), while heating the dyed fabric to about 100 ° C. at a processing speed of 0.5 m / min,
It was packed in a crimper box in the length direction, and the pressing pressure was adjusted to perform a fine buckling formation treatment. The discharged processed fabric has stripe-shaped wrinkles that are substantially parallel to each other in the width direction, and the wrinkles have fine appearances in which fine buckling irregularities having a buckling number of 12 peaks / in are formed in the length direction. A napped artificial leather was obtained.

The elongation rate and elongation recovery rate of the artificial leather thus obtained were measured and found to be as shown in Table 1 below. Example 2 As the island component of the polymer mutual array fiber of Example 1, 1,
3 Propylene diol was used, except that polypropylene terephthalate having an intrinsic viscosity of 0.89 was used, the processing was carried out under the same conditions as in Example 1, and there were substantially parallel wrinkles, and the wrinkles were long. An artificial leather with a nap-like appearance having a different appearance was obtained in which fine buckling irregularities having a buckling number of 12 peaks / in in the vertical direction were formed.

The elongation ratio and elongation recovery ratio of the artificial leather thus obtained were measured and the results are shown in Table 1 below. Example 3 In Example 2, a mixture of polyhexamethylene carbonate diol having a molecular weight of 2000 as a polymer elastic body and neopentyl adipate diol having a molecular weight of 2000 at a ratio of 70:30 wt% and 4,4′-diisocyanate as a diisocyanate. Processing was carried out under the same conditions as in Example 2 except that a solution prepared by diluting polyurethane polymerized using phenyl methane diisocyanate and methylenebisaniline as a chain extender with DMF was used. The discharged processed fabric has stripe-shaped wrinkles that are substantially parallel to each other in the width direction, and the wrinkles have fine appearances in which fine buckling irregularities having a buckling number of 12 peaks / in are formed in the length direction. A napped artificial leather was obtained.

The elongation rate and elongation recovery rate of the artificial leather thus obtained were measured and found to be as shown in Table 1 below. Comparative Example 1 Using a circular dyeing machine, the raw fabric of Example 1 was used at 125 ° C.
With disperse dye, dye it brown and add a finishing agent,
Drying treatment was performed to obtain a napped artificial leather in which the product surface looks uniform.

The elongation rate and elongation recovery rate of the artificial leather thus obtained were measured and found to be as shown in Table 1 below.

[0051]

[Table 1]

[0052]

EFFECT OF THE INVENTION The artificial leather of the present invention has excellent stretchability and, unlike the conventional uniform surface appearance, has wrinkles in the form of stripes that are substantially aligned in the width direction, and the wrinkles have a long length. A napped or silver-finished artificial leather with a unique appearance in which fine buckling irregularities are formed in the direction.

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Claims (10)

[Claims] 1. A sheet in which a polymer elastic material is applied to an entangled body of ultrafine fibers and / or ultrafine fiber bundles, which is provided with a fine buckling structure in the lengthwise direction of the sheet, and is substantially widthwise. An artificial leather having excellent stretchability, which has a line-shaped wrinkle pattern, has an elongation rate of 10% or more in the longitudinal direction and an elongation recovery rate of 85% or more. 2. The artificial leather excellent in stretchability according to claim 1, wherein the sheet has naps on at least one surface. 3. The artificial leather excellent in stretchability according to claim 1, wherein the sheet has a silver surface on at least one surface. 4. The polymer forming the entangled body of ultrafine fibers and / or ultrafine fiber bundles comprises polypropylene terephthalate and copolymers thereof.
The artificial leather described in 2 or 3, which has excellent elasticity. 5. The artificial leather excellent in stretchability according to claim 1, wherein the polymer elastic body comprises a polymer diol containing 30% by weight or more and 90% by weight or less of polycarbonate diol. . 6. A sheet in which a polymer elastic material is applied to an entangled body of ultrafine fibers and / or ultrafine fiber bundles, at 50 ° C. or higher, 18
Artificially superior in stretchability, characterized by being continuously packed in the length direction so that the number of bucklings is 5 peaks / in or more while heating at 0 ° C or lower, forming buckling, and then taking out. Method of manufacturing leather. 7. The method for producing an artificial leather excellent in stretchability according to claim 6, wherein the sheet has at least one raised hair. 8. The method for producing an artificial leather having excellent stretchability according to claim 7, wherein the sheet has at least one silver surface. 9. Stretchability according to claim 6, 7 or 8, characterized in that polypropylene terephthalate and copolymers thereof are used as a polymer forming an entangled body of ultrafine fibers and / or ultrafine fiber bundles. Excellent manufacturing method for artificial leather. 10. The artificially excellent stretchability according to claim 6, 7, 8 or 9, wherein the polymer elastic body is a polymer dio containing 30% by weight or more and 90% by weight or less of polycarbonate diol. Method of manufacturing leather.