JP2003253571A - Artificial leather having excellent stretchability in longitudinal direction and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a casual-like artificial leather having excellent longitudinal stretchability and stretch recovery as well as high strength and durability and having a unique appearance in contrast with ordinary plain surface appearance. <P>SOLUTION: A number of creases having the form of ridges and furrows essentially discontinuous in lateral direction and essentially having a number of pitches in longitudinal direction are formed on at least one surface of a sheet composed of an interlocked material of ultrafine fibers and/or ultrafine fiber bundles and a polymeric elastomer and a stretchable sheet is bonded to a surface of the above sheet to obtain an artificial leather having a longitudinal elongation of ≥10% and a longitudinal stretch recovery of ≥85%. The method for the production of the artificial leather comprises the application of a polymeric elastomer to an interlocked material of ultrafine fibers and/or ultrafine fiber bundles, the stuffing of the obtained sheet essentially continuously in longitudinal direction at a stuffing ratio of 5-50% under heating at 80-190°C to generate creases on the surface by the buckling of the sheet and the bonding of a stretchable sheet on one surface of the sheet. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial leather which is particularly excellent in stretchability in the vertical direction and elongation recovery rate, and has a strong product strength, and a method for producing the same.

[0002]

2. Description of the Related Art It has been 5 to 6 years since the demand for stretch materials on the market, but the ease with which artificial leather clothing can be worn,
From the viewpoint of high-order workability, the demand is still high.
In order to meet these demands, as a conventional technique, for example, as a manufacturing method for obtaining an artificial leather excellent in stretchability, as described in JP-A-48-18579, non-elastic fibers and polyurethane are mainly used. Method for producing a non-woven fabric structure in which elastic fibers are mixed or laminated, and Japanese Patent Publication No. 40-2792
Japanese Patent Laid-Open No. 61-41742, Japanese Patent Publication No. 1-4
In Japanese Patent Publication No. 1742 and Japanese Unexamined Patent Publication No. 5-339863, a nonwoven fabric structure is formed by using a composite fiber in which ultrafine non-elastic fibers and ultrafine elastic fibers mainly composed of polyurethane are used alone or with the same island component. A method is disclosed in which after removing the sea component to form a structure composed of ultrafine non-elastic fibers and ultrafine elastic fibers, a part of the elastic fibers is dissolved or glued.

Regardless of the technique, the ultrafine elastic fiber of polyurethane is indispensable, and the ultrafine elastic fiber is bonded to the ultrafine inelastic fiber by heating, and the texture becomes hard in the area to obtain satisfactory properties, and in the dyeing process. It is difficult to color, and the surface of the product is irritated.

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. In any of the technologies, in the leather manufacturing process, a processing tension in the vertical direction is necessary for stabilizing the processing, and therefore the vertical direction of the processed sheet is stretched, so that the horizontal elongation is obtained although the horizontal direction is obtained. The current situation is that it will drop significantly.

Further, in Japanese Patent Laid-Open No. 2000-303365, a sheet obtained by applying polyurethane to a non-woven fabric made of ultrafine fibers is subjected to hot water treatment with a jet dyeing machine to obtain a dyeing temperature +
Although a method of performing dry heat treatment at 30 ° C and then dyeing is disclosed, it is stretched by the liquid flow resistance in the final dyeing treatment and stretchability in the horizontal direction is obtained, but stretchability in the vertical direction is difficult to obtain. Met.

[0006]

DISCLOSURE OF THE INVENTION The present invention satisfies the vertical stretchability, the elongation recovery rate, and the high strength of the product, which cannot be achieved by the above-mentioned conventional techniques, and has the conventional stretchability. The purpose of the present invention is to provide artificial leather rich in casual-like leather that has a special surface structure, not a plain surface appearance, and a manufacturing method thereof.

[0007]

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

That is, the artificial leather of the present invention which is excellent in stretchability in the vertical direction has the following constitution (1). (1) On at least one surface of a sheet composed of an entangled body of ultrafine fibers and / or an ultrafine fiber bundle and a polymer elastic body, the sheets are present at a substantially large number of pitches in the lengthwise direction and substantially in the widthwise direction. Sheet having a large number of wrinkles present by presenting discontinuous stripe-shaped irregularities, and having a stretchable sheet adhered to one surface of the sheet, the vertical elongation rate is at least 10% or more, and the vertical elongation recovery rate is Artificial leather with excellent stretchability in the vertical direction, characterized by being 85% or more.

Further, in the artificial leather of the present invention,
Preferably, it has the following configurations (2) to (4). (2) The artificial leather excellent in vertical stretchability according to the above (1), wherein the polymer forming the entangled body of the ultrafine fibers and / or the ultrafine fiber bundle is polyethylene terephthalate or a copolymer thereof. . (3) The artificial leather excellent in vertical stretchability described in (1) above, wherein the polymer forming the entangled body of the ultrafine fibers and / or the ultrafine fiber bundles is polypropylene terephthalate or a copolymer thereof. . (4) The polymer elastic body contains 3 parts of polycarbonate diol.
(1), (2) or (3), characterized in that the polymer diol is contained in an amount of 0% by weight to 90% by weight.
Artificial leather with excellent stretchability in the vertical direction.

Further, the method for producing an artificial leather excellent in vertical stretchability of the present invention has the following constitution (5). (5) Substantially 80 ° C. or higher of a sheet in which a polymer elastic body is attached to an entangled body of ultrafine fibers and / or ultrafine fiber bundles,
While heating at 190 ° C. or lower, it is packed substantially continuously in the longitudinal direction so as to have an indentation ratio of 5% or more and 50% or less, and the sheet surface is buckled to form one surface of the sheet. A method for producing artificial leather having excellent vertical stretchability, which comprises bonding at least a stretchable sheet to (6) Polyethylene terephthalate or copolymers thereof are used as a polymer for forming an entangled body of ultrafine fibers and / or ultrafine fiber bundles (5)
A method for producing an artificial leather having excellent stretchability in the vertical direction. (7) Polypropylene terephthalate or copolymers thereof are used as the polymer forming the entangled body of the ultrafine fibers and / or the ultrafine fiber bundles, the artificial leather having excellent vertical stretchability according to the above (5). Manufacturing method. (8) The polymer elastic body contains 3 parts of polycarbonate diol.
(5), (6) or (7), characterized in that a polymer diol is used in an amount of 0% by weight to 90% by weight.
A method for producing an artificial leather having excellent stretchability in the vertical direction.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The artificial leather according to the present invention will be described in more detail below.

The artificial leather according to the present invention has at least a vertical elongation rate of 10% or more and a vertical elongation recovery rate of 85% or more, and is particularly excellent in vertical stretchability and has a structure. First, at least one surface of an artificial leather sheet composed of a entangled body of ultrafine fibers and / or ultrafine fiber bundles and a polymer elastic body is present with a substantially large number of pitches in the longitudinal direction of the sheet, and ,
It has a large number of wrinkles that are present as stripe-shaped irregularities that are substantially discontinuous in the width direction. That is, the large number of wrinkles are present at a fine pitch to be described later, in the form of wrinkles having fine irregular wrinkles, and the extending direction of the wrinkles is substantially the width of the artificial leather sheet. Direction. Each wrinkle is not completely continuous from end to end in the sheet width direction, and in most cases, the wrinkle has a certain length in the width direction (about 1 cm to several tens of cm). , Or more), it exists in the form of fine wrinkles with a fine pitch so that a large number of waves are continuously gathered in a discontinuous state.

That is, "existing at a substantially large number of pitches in the length direction" means that the buckling caused by pushing the sheet in the length direction forms fine irregularities on the surface, The length from that convex portion to the next convex portion is called a pitch, and it means that a large number of this pitch exists in the length direction. Further, "existing by presenting substantially discontinuous stripe-shaped unevenness in the width direction" means that due to buckling that occurs in the length direction of the sheet, fine unevenness is formed on the sheet surface,
It is said that the convex portion and the concave portion are separately connected in the width direction of the sheet with a certain length, and such a state exists on the entire surface of the sheet. In addition, "streak-like unevenness" means that the wrinkle itself presents a fine uneven structure in the form of stripes to form wrinkles. "A large number" means a state in which the wrinkles described above are continuously present in the sheet length direction so that waves are continuously gathered at a pitch as described later.

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, those made of polyethylene terephthalate or copolymers thereof are preferably used from the viewpoint of durability and dyeability, and
From the viewpoint of stretchability and flexibility, polypropylene terephthalate or copolymers thereof are preferably used.

As the polypropylene terephthalate,
A polyester obtained using terephthalic acid as a main acid component and 1,3 propanediol as a main glycol component. However, 20 mol%, more preferably 10%
It may contain other copolymerizable components capable of forming an ester bond in the following proportions.

In this case, as the copolymerizable compound, for example, diphthalic acid such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid, sebacic acid, and the like, and as the glycol component, for example, ethylene glycol, 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 of the ultrafine fibers, a bimetal type, an eccentric type in which one component is exposed, and the like are preferably used in order to exhibit elasticity. These polymers may contain additives such as a light resistance agent, a pigment, a matting agent, an antistatic agent, and a flame retardant.

These ultrafine fibers may be directly spun monofilaments, or may be obtained by dividing a multicomponent composite fiber into individual components or removing one component. It may be. 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 0.55 dtex or less, more preferably 0.11 dtex or less, from the viewpoints of fine pitch formation, surface touch of the final product, flexibility and the like. Is good. The cross-sectional shape of these fibers is not particularly limited.

The sheet in which the elastic polymer is added to the entangled body of the ultrafine fibers and / or the ultrafine fiber bundles in the present invention means
It is an indication that a entangled body of ultrafine fibers and / or an ultrafine fiber bundle is impregnated with a polymer elastic material uniformly or distributed, or a sheet structure in which a silver surface is formed on the surface of the impregnated sheet. .

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 the napped hair is not particularly limited. For example, the above-mentioned sheet is surface-ground by sand paper used in the method for manufacturing a napped artificial leather, and a raising treatment using a cloth is used. It can be easily formed by using, for example. 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 that is commonly used in the method for producing artificial leather with silver, and the dry or It can be obtained by solidifying by a wet method.

For example, in the case of a non-woven fabric structure, a web is formed from the above-mentioned monofilament or composite short fibers by using a card cloth wrapper or random webber, and needle punch, water jet punch or a combination thereof is used. Perform entanglement treatment using, and if necessary, combine processing such as shrinkage treatment, gluing agent addition and ultrafine treatment, and give a polymer elastic body to this entanglement,
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 material, acrylic-butadiene copolymer, styrene-butadiene copolymer, polybutadiene, synthetic rubber 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 3,000 is preferable, among which 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 polymer 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, preferably Is preferably 10 to 50% by weight. If it is less than 5% by weight, stretch recovery and flexibility may be good, but the elongation recovery rate and product durability may decrease, which is not preferable.
If it exceeds 0% by weight, the fine crimp forming property under heating, which will be described later, becomes low, and the elongation tends to decrease, which is not preferable in some cases.

The sheet to which the above-mentioned polymer elastic material is applied, which is used in the artificial leather of the present invention, preferably has a basis weight of 400 g / m ² or less, more preferably 100 to 300.
It is g / m ² . The thickness is preferably 2 mm or less,
More preferably, it is 1 mm or less. If it deviates from this range, it may be difficult to perform fine pitch formation, streak-shaped wrinkle formation, wrinkle pattern formation, etc., which is not desirable, and it becomes difficult to realize a high and good elongation rate.

As the lower limit, the basis weight and thickness at which a sheet can be formed are limited, but if both the basis weight and the thickness are too low, the texture may be paper-like and the buckling feeling may be too strong, which is not preferable. Is a basis weight of 60 g / m ² ,
The thickness is about 0.2 mm.

The present invention does not impair the effects of the present invention even if the sheet is perforated in the thickness direction of the sheet and discontinuously punched in the surface direction.
Rather, it may be preferable in some cases to further enhance elasticity, and by exerting a design effect by consciously changing the color of the sheet color and the material to be adhered by adhering to a woven fabric, knitting or non-woven fabric described later. This is preferable because it is possible. The shape of the hole may be any of circle, rhombus, triangle, ellipse, etc. and is not particularly limited.

The method for producing the artificial leather of the present invention will be described below.

That is, according to 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 heated to substantially 80 ° C. or higher, 1
While heating at 90 ° C. or less, by filling the filling space substantially continuously in the length direction so that the indentation ratio is 5% or more and 50% or less, or by performing heat treatment in the filled state. After forming a buckle on the sheet surface,
At least a stretchable sheet is bonded to one surface of the sheet.

In the method of the present invention, the phrase "buckling into the packing space or performing heat treatment in the packed state to cause buckling of the sheet surface" heats the ultrafine fibers and the elastic polymer. This means that a large number of the wrinkle structures described above are formed on the surface of the sheet by making them easily deformable and making the pushing ratio easily adjustable. With ultrafine fibers alone, although buckling occurs when the sheet thickness increases, a fiber with a high elongation recovery rate cannot be obtained. It is extremely important for enhancing the effect of the present invention that the polymeric elastic body is simultaneously applied to the sheet.

The term "pushing ratio" means that the length of the sheet before processing is buckled and stuffed into the length obtained by multiplying the sheet length before stuffing by 5% to 50%. This is called "pushing ratio", and is not a value obtained by dividing the length of the product subjected to the buckling formation treatment by the length before processing. Therefore,
If the sheet thickness, fiber thickness, polymer elastic body, etc. are different,
Even if the indentation ratio is 30%, different streaky irregularities appear in the final product, and many pitch dimensions are also different.

As a concrete example of the buckling formation using the packing space, by using the above-mentioned artificial leather sheet, for example, a metal nip roll of a crimper device used for crimping fibers is widened. While pushing the sheet while the nip roll is rotating, it is sent to the stuffing box where the gap at the roll outlet can be adjusted, the pressure at the stuffing box outlet is adjusted to a predetermined pressure, and the continuously buckled sheet is discharged. It can be carried out. 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 a method that can be recommended to continuously push into.

By using such a method, a large number of stripe-shaped uneven wrinkles which are present at a substantially fine pitch in the length direction on at least one surface of the sheet are formed and imparted in the width direction. It is possible to form many discontinuous wrinkles.

The wrinkle pitch which is present in the lengthwise direction means the buckling state formed by fine irregularities in the lengthwise direction on at least one surface of the sheet.
It is a value obtained by counting the number of streak-shaped wrinkles formed by the convex portions in a length of 25.4 mm and dividing 25.4 mm by the number.

The artificial leather of the present invention which is excellent in stretchability in the vertical direction has a pitch of 2000 μm or less, preferably 150.
It is preferably 0 μm or less, more preferably 800 μm or less. If it exceeds 2000 μm, it will be difficult to achieve a high elongation rate, and the lower limit is the limit of this type of indentation processing method.
It is a degree.

The wrinkles in the form of stripes which are discontinuous in the width direction of the sheet are
The convex portions forming the above-mentioned pitch form a linear discontinuous pattern in a lateral (width) direction in a substantially linear shape, a substantially curved shape, or a mixture of these.

The large number of fine pitches may be present on one side or both sides of the sheet. For example, in a napped artificial leather, when the above-mentioned large number of pitches are present on both surfaces, the smoothness of the surface touch of the non-adhesive surface may be a concern in the adhesion with the elastic sheet described later. In such a case, a large number of pitches are formed only on one side by positively heating only one side of the sheet and pressing the one side without heating. By bonding a stretchable sheet to this surface, it is possible to obtain a stretchable artificial leather having a smooth surface touch. Although a large number of pitches are formed on both sides when such a process is applied to the spunbonded nonwoven fabric, the artificial leather of the present invention is obtained by impregnating a entangled body of ultrafine fibers with a polymer elastic body,
By appropriately washing the polymeric elastic body under heating conditions, it is possible to give different appearances to the front and back.

The artificial leather of the present invention has at least 10% of elongation in the longitudinal direction while having the above-mentioned surface article having a different appearance.
As described above, the artificial leather is characterized in that the elongation recovery rate is 85% or more, and in order to impart the elongation rate and the elongation recovery rate related to the stretchability, in the above method for forming buckling wrinkles,
It is important to heat both sides or one side of the sheet to be pushed in continuously.

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 sheet is 80 ° C or higher and 190 ° C or lower, preferably 100 ° C to 170 ° C. If the temperature is lower than 80 ° C., it is difficult to impart a fine pitch, and the setability of the buckled structure is deteriorated. On the other hand, when the temperature exceeds 190 ° 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 impart a large number of fine pitches and enhance stretchability, the indentation ratio of the sheet is important under the above temperature conditions, and the ratio is 5% or more, preferably 10% or more, more preferably Is better than 20%. 5
If it is less than%, the pitch becomes large and it becomes difficult to obtain sufficient stretchability. Further, the upper limit is limited due to this kind of device mechanism, and the upper limit is about 50%.

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

In the present invention, a stretchable sheet is adhered to the above-mentioned stretch-contracting bending-forming sheet in order to further enhance the strength and stretch back property.

The stretchable sheet means that the sheet has an elongation rate of 10% or more and an elongation recovery rate of 85% or more in the length direction and can be adhered by an adhesive described later. Yes, specifically, it is made of a woven fabric, a knitted fabric, a non-woven fabric, or the like, and as the constituent fibers thereof,
For example, polyamides such as nylon 6, nylon 66, nylon 12, copolymer nylon, polyethylene terephthalate, copolymer polyethylene terephthalate, polybutylene terephthalate or copolymers thereof, polypropylene terephthalate or copolymers thereof, polylactic acid or copolymer Examples thereof include copolymers, polyolefins, polyurethanes and copolymers thereof. Among them, polypropylene terephthalate and copolymers thereof, polyurethane and copolymers thereof are preferably used from the viewpoint of elasticity and flexibility.

In order to obtain a stretchable sheet, for example, in the case of a woven fabric, there is a limit in increasing the stretchability systematically, and false twisted yarns, elastic yarns or covering yarns are combined as constituent yarns. In the case of knitting, a stretchable structure can be formed by a weaving structure such as rubber knitting or tricot knitting. By combining the above-mentioned constituent yarns, it is possible to further increase the stretchability. The thickness and cross-sectional shape of these constituent fibers, the structure and the basis weight are not particularly limited and may be appropriately selected depending on the intended final product.

It is necessary that these sheets have an elongation rate of 10% or more and an elongation recovery rate of 85% or more in at least the vertical direction. When the elongation rate is less than 10%, the elongation of the buckling sheet having elasticity is restricted, and when the elongation recovery rate is less than 85%, the stretch back property is deteriorated, which is not desirable.

Further, these sheets may be dyed. When the sheet made of the entangled body of the ultrafine fibers and / or the ultrafine fiber bundle and the polymer elastic body is dyed, by consciously changing the color of the dyed sheet and the color of the material to be adhered In some cases, it may be preferable to exert a design effect.

The above-mentioned sheets can be adhered to each other by using conventional resins such as polyurethane-based, polyacrylic-based, polyester-based, polyvinyl chloride-based adhesives, etc., as the adhesive, and the texture and durability of the product. From the viewpoint of properties, polyurethane-based, polyester-based, polycarbonate-based or copolymerized polyurethanes thereof are preferably used.

In the present invention, these resins are blended in an appropriate concentration according to the intended final product and applied to the sheet surface by a method such as reverse roll coating, gravure coating, knife coating, spraying, Solidify by dry or wet method. Further, if the effect of the present invention can be exerted, it is not always necessary to apply it to the entire surface of the sheet, and it may be applied and adhered in a dot shape. As a bonding method other than these resins, for example, it is also possible to bond and integrate them by heating and pressing with a heat-sealing sheet interposed.

By adopting the above-mentioned structure, the present invention satisfies at least the stretchability in the vertical direction, the elongation recovery rate and the high strength of the product, which cannot be achieved by the conventional technique, and has the conventional stretchability. It is possible to provide casual-like artificial leather with a fine buckling structure instead of a plain surface appearance.

[0055]

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
The sheet is stretched to 1.8 kg at m / min, the gripping interval at that time is measured, and the stretching rate (%) is calculated by the following formula, which is represented by the average value of three sheets.

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 taken 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. It takes 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 repeated 5 times elongation A sample with the above length <tensile strength> 2 cm x 18 cm in the length direction,
Three samples each in the width direction, humidity and temperature 65%
After standing at 24 ° C. for 1 hour, tensile measurement was carried out with an Autograph Tensilon tensile tester at a test length of 10 cm and a tensile speed of 100 cm, and the average value of 3 sheets is shown. 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, the island / sea component ratio = 60/40% by weight, the cut length is 51 mm, and the composite fineness is Staples provided with crimps of 3.3 dtex and 36 islands were prepared.

This 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 25 per microfiber.
After being wet-solidified, the product was washed with hot water and dried.

This 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 .

A circular dyeing machine was used for this greige, and 1
It was dyed brownish with a disperse dye at 25 ° C., a finishing agent was applied, and a drying treatment was performed.

After that, a Microcreper device (manufactured by UMICREX Corporation, USA)
While heating the raised surface of the dyed fabric to about 150 ° C. at a processing speed of 45 m / min, the pushing rate in the length direction is 1
It was packed in a crimper box so as to be 5%, and the pressing pressure was adjusted to perform a fine buckling formation treatment.

Then, a non-brushed surface of the sheet was coated with a one-pack type polyester polyurethane solution by a gravure coater, and the coated surface had a polyester 22dtex-12F on the front of the tricot half and a polyurethane elastic yarn 22dtex- on the back. 130 using 4F 15%
Growth rate of 3 calls / in, 82 wales / in
A knitted fabric having a stretch recovery rate of 7% and a recovery rate of 92% was placed on the knitted fabric, lightly pressed with a mangle, and then dried with a drier to remove the solvent.

The artificial leather thus obtained has a pitch of 5
An artificial leather having a wrinkle of 63 μm and discontinuous in the width direction and having a stretchable sheet adhered to one surface of the sheet was obtained.

The elongation ratio and elongation recovery ratio of this artificial leather were measured and found to be extremely good as shown in Table 1 below. Example 2 As the island component of the polymer mutual array fiber of Example 1, 1,
Processing was carried out under the same conditions as in Example 1 except that polypropylene terephthalate having an intrinsic viscosity of 0.89 using 3 propanediol was used.

The artificial leather thus obtained has wrinkle-like wrinkles having a pitch of 515 μm in the length direction and discontinuous in the width direction, and a stretchable sheet is adhered to one surface of the sheet. An artificial leather with a different appearance was obtained.

When the longitudinal elongation rate, longitudinal elongation recovery rate and tensile strength elongation rate of this artificial leather were measured, the results were very good as 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 artificial leather thus obtained has wrinkles in the form of stripes having a pitch of 495 μm in the length direction and discontinuous in the width direction, and a stretchable sheet is adhered to one surface of the sheet. An artificial leather with a different appearance was obtained.

When the longitudinal elongation rate, the longitudinal elongation recovery rate and the tensile strength of this artificial leather were measured, they were extremely good 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 longitudinal elongation rate, the longitudinal elongation recovery rate, and the tensile strength elongation rate of the artificial leather thus obtained were measured and found to be inferior to those of the present invention as shown in Table 1 below. .

[0071]

[Table 1]

[0072]

INDUSTRIAL APPLICABILITY The artificial leather of the present invention has particularly improved vertical stretchability and elongation recovery rate, and at the same time satisfies the high strength and high durability of the product, and the surface has a different napped appearance or silver finish. It realizes the artificial leather of the tone.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F055 AA01 BA12 BA30 CA18 DA04                       DA07 EA04 EA09 EA12 EA16                       EA23 EA24 EA34 FA19 GA03                       GA32 GA40 HA03 HA11 HA22

Claims (8)

[Claims] 1. A sheet comprising an entangled body of ultrafine fibers and / or ultrafine fiber bundles and a polymer elastic body is present at a substantially large number of pitches in the lengthwise direction and in the widthwise direction. A sheet having a large number of wrinkles presenting substantially discontinuous streaky irregularities and having stretchability is adhered to one surface of the sheet, and at least a vertical extension rate of 10% or more, vertical extension recovery Artificial leather with excellent elasticity in the vertical direction, characterized by a ratio of 85% or more. 2. The polymer forming the entangled body of ultrafine fibers and / or ultrafine fiber bundles is made of polyethylene terephthalate or copolymers thereof.
Artificial leather with excellent stretchability in the vertical direction. 3. An artificial polymer having excellent vertical stretchability according to claim 1, wherein the polymer forming the entangled body of the ultrafine fibers and / or the ultrafine fiber bundle is polypropylene terephthalate or a copolymer thereof. leather. 4. The artificial leather excellent in vertical 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. . 5. A sheet in which a polymeric elastic material is applied to an entangled body of ultrafine fibers and / or ultrafine fiber bundles is substantially at 80 ° C.
As described above, while heating at 190 ° C. or less, the sheets are packed substantially continuously in the longitudinal direction so that the indentation ratio is 5% or more and 50% or less, and the sheet is buckled to form the sheet, and then the sheet is formed. A method for producing artificial leather having excellent stretchability in the vertical direction, which comprises bonding at least a sheet having stretchability to one surface. 6. An artificial body excellent in stretchability in the vertical direction according to claim 5, characterized in that polyethylene terephthalate or a copolymer thereof is used as a polymer forming an entangled body of ultrafine fibers and / or ultrafine fiber bundles. Method of manufacturing leather. 7. An artificial polymer having excellent vertical stretchability according to claim 5, characterized in that polypropylene terephthalate or copolymers thereof are used as the polymer forming the entangled body of the ultrafine fibers and / or the ultrafine fiber bundles. Method of manufacturing leather. 8. An artificial leather having excellent stretchability in the vertical direction according to claim 5, wherein the polymer elastic body uses a polymer diol containing 30% by weight or more and 90% by weight or less of polycarbonate diol. Manufacturing method.