JP3103434B2 - Flexible suede-like artificial leather and manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suede-like artificial leather excellent in stretchability and leveling of nap.
More specifically, the present invention is capable of repeatedly performing elongation deformation,
The present invention relates to a suede-like artificial leather having substantially no structural deformation, that is, excellent in stretchability and fiber entanglement, and excellent in leveling properties of nap fibers and having a soft and full texture.

[0002]

2. Description of the Related Art Conventionally, as an entangled nonwoven fabric having excellent elasticity, short fibers obtained by flash-spinning polyurethane are deposited, and a fiber intersection is adhered by a method such as self-adhesion. As described in Japanese Patent No. 8177, a long-fiber nonwoven fabric of polyurethane obtained by a spun bond method is known. However, in the case of these polyurethane nonwoven fabrics, since the fibers themselves are too strong and too flexible, it is difficult to form a sufficient fiber entangled body by a conventionally known entanglement such as needle punching or a fluid jet method. For example, Japanese Unexamined Patent Publication No. 48-18579 proposes a nonwoven fabric obtained by mixing 5 to 80% by weight of elastic fibers with inelastic fibers as a material having elasticity and strength. However, since elastic fibers differ in rigidity and elongation elasticity so as to be incomparable with inelastic fibers, it is extremely difficult to mix fibers sufficiently to obtain a good web with a card machine, and furthermore to obtain good bonding. It is. Japanese Patent Application Laid-Open No. 52-85575 describes a method of forming an entangled nonwoven fabric using a composite fiber comprising an inelastic polymer and an elastic polymer, and then peeling the nonwoven fabric from each component polymer. And the inelastic polymer are constrained in the same state, and therefore cannot have sufficient elasticity structurally. In addition, Japanese Patent Publication 40-2792
In the publication, a mixed spun fiber composed of an elastic polymer and an inelastic polymer is mixed into a nonwoven fabric, and at least one of the inelastic polymers in the fibers constituting the obtained nonwoven fabric is dissolved. Methods have been proposed for resolidifying the polymer in a nonwoven fabric. According to this method, a nonwoven fabric having good entanglement can be obtained, but none of the nonwoven fabric has sufficient elasticity because the elasticity of the nonwoven fabric is governed by the fibers made of the inelastic polymer.

[0003] Japanese Patent Publication No. 41742/1989 proposes a method for producing an elastic nonwoven fabric by blending an elastic fiber and an inelastic fiber obtained by removing one component from a conjugate fiber. However, when used for napping products, napping of elastic fiber and napping of inelastic fiber are mixed, and It was lacking in uniformity in terms of color development. Japanese Patent Application Laid-Open No. 61-201086 discloses that an ultrafine fiber made of an inelastic polymer and an ultrafine fiber made of an elastic polymer are made of an elastic polymer by removing a sea component from a nonwoven fabric of a composite sea-island fiber existing in the same sea component. It describes a sheet-like material that partially dissolves ultrafine fibers and serves as a binder.However, since the elastic polymer binds and adheres the ultrafine fiber made of the inelastic polymer, a soft texture of the ultrafine fibers cannot be obtained. In addition, since the elastic polymer is an ultrafine fiber, the stress is reduced, and the desired elasticity cannot be obtained. As described above, at present, a suede-like artificial leather having good workability, elasticity, and excellent nap uniformity has not been obtained.

[0004]

In the conventionally known methods for producing nonwoven fabrics, suede-like artificial leather having both entanglement and elasticity and having an elegant and uniform nap when formed into a nap sheet Was not obtained. It is an object of the present invention to provide a soft suede-like artificial leather having uniform elongation elasticity as a stretchable nonwoven fabric, having a very soft and fulfilling texture, and having a uniform surface when formed into a napped sheet.

[0005]

SUMMARY OF THE INVENTION The present invention provides an ultrafine fiber comprising a pair of an ultrafine fiber bundle made of an elastic polymer (elastic ultrafine fiber bundle) and an ultrafine fiber bundle made of an inelastic polymer (an inelastic ultrafine fiber bundle). A sheet-like material formed by forming naps on at least one surface of a nonwoven fabric in which bundled fibers are three-dimensionally entangled, and the ultrafine fiber bundles are formed by the elastic ultrafine fiber bundle having a portion between the inside thereof and the inelastic ultrafine fiber bundle. Stalemate,
A suede-like artificial leather characterized by being stuck to a part of other ultrafine fiber bundles, and two sea islands having an island component group composed of an elastic polymer and an island component group composed of an inelastic polymer. A step of fabricating an entangled nonwoven fabric using the microfiber bundled fiber-generating fiber adjacent to the structure, a step of shrinking the entangled nonwoven fabric, and a step of transforming the microfiber bundled fiber-generating fiber into a microfiber bundled fiber; A method for producing artificial suede leather comprising a step of forming nap on at least one surface and a step of dyeing the obtained fiber nap substrate.

[0006] The fibers constituting the base layer of the suede-like artificial leather of the present invention are an ultrafine fiber bundle (elastic ultrafine fiber bundle) composed of a pair of elastic polymers and an ultrafine fiber bundle (inelastic ultrafine fiber bundle) composed of an inelastic polymer. Are bundled ultrafine fibers. Similarly, even in the case of the ultrafine fiber bundled fiber in which the elastic microfiber and the inelastic microfiber are bundled, the present invention is applicable to the fiber in which the elastic microfiber and the nonelastic microfiber form a bundle in a mixed state. I can not achieve my purpose. The ultrafine fiber bundled fiber of the present invention is obtained by removing sea components from an ultrafine fiber bundle-generated fiber in which two sea-island structures having an island component group composed of an elastic polymer and an island component group composed of an inelastic polymer are adjacent to each other. Can be

That is, the microfine fiber bundle-forming fiber used in the present invention is composed of an inelastic microfine fiber bundle generating fiber whose island fiber component is an inelastic polymer and an elastic microfine fiber bundle generating fiber whose island component is an elastic polymer. Is a fiber having a structure in which the two sea-island structural fibers are attached in a side-by-side manner. As a method for producing such fibers, two sea-island fibrous components having an elastic polymer or an inelastic polymer obtained as an island component obtained by mixing and melting polymer chips or by separately melting and repeating division and integration are used. In the side-by-side composite spinning method, and in the spinning method of the multi-core core-sheath fiber, the core component is divided into right and left, and an inelastic polymer and an elastic polymer are supplied to each, and the respective core components are arranged so as to be adjacent in a block shape. And spinning using a spinning nozzle. The cross-sectional shape of the fiber may be a circular cross-section, an elliptical shape, an irregular cross-section such as a cocoon shape,
It may be a hollow fiber. In any case, the elastic microfine fiber component and the inelastic microfine fiber component may be bundles of fibers having substantially the same cross-sectional shape without substantial mixing.

The ratio of the inelastic ultrafine fiber component to the elastic ultrafine fiber component is 95/5 to 5/95, preferably 85/15 to 3
0/70. When the inelastic fiber is 95% or more, the obtained sheet lacks flexibility, the elastic fiber has little sticking and the fiber is easy to come off. On the other hand, when it is 5% or less, the texture is soft but the suede appearance is obtained. It is far from. The fineness of the ultrafine fibers constituting the ultrafine fiber bundles is 0.5 denier or less, preferably 0.1 denier to 0.002 denier. Single fiber fineness is 0.
When the denier is 5 denier or more, the suede-like appearance is inferior and the texture becomes hard. On the other hand, when it is 0.002 denier or less, the ultrafine fibers are too fine and the coloring property is poor.

The elastic polymer of the island component used in the present invention means that the polymer is formed into a fiber, and the fiber is formed at room temperature.
A polymer whose elongational elastic recovery after 1 minute at 0% elongation is 50% or more, and an inelastic polymer whose elongational elasticity recovery measured in the same manner is 50% or less or a limit at room temperature. It means a polymer whose elongation does not reach 50%. The inelastic polymer used for the island component is, for example, polyethylene terephthalate or a copolymer based on the same, polybutylene terephthalate or a copolymer based on the same, an aliphatic polyester or a spinnable polyester such as a copolymer thereof. , Nylons represented by nylon 6, nylon 66, nylon 610, nylon 12, other spinnable polyamides, polyolefins such as polyethylene, polypropylene and polybutylene, acrylic copolymers, polyvinyl alcohol, etc. Can be

On the other hand, the elastic polymer used for the island component may have an average molecular weight of 5 such as polyester diol, polyether diol, polyester ether diol, polylactone diol, polycarbonate diol, and the like.
Conjugated diene polymers or conjugated diene polymers such as polyurethanes, polyisoprene, and polybutadiene obtained by reacting at least one selected from polymer diols having a molecular weight of from 0 to 3500 with an organic diisocyanate and a chain extender having two active hydrogen atoms. Examples of the polymer include a polymer having a united block in a molecule and other polymers capable of spinning and exhibiting the above-described rubber elasticity behavior.

Further, the polymer constituting the sea component is a polymer having a different solubility or degradability in a specific solvent or decomposer from the inelastic polymer and the elastic polymer of the island component, and has a thermoforming temperature range. Are overlapping,
In the molten state, a polymer that does not cause a reaction or interaction that causes a problem in spinning between these polymers within the time required for spinning is used. For example, it is at least one polymer selected from polymers such as polyethylene, polypropylene, ethylene propylene copolymer, ethylene vinyl acetate copolymer, polystyrene, styrene acrylic copolymer, and styrene ethylene copolymer. The sea component to be combined with the inelastic polymer and the elastic polymer may be the same or different, but when different ones are used, the spinning properties, the prevention of fiber cracking in the nonwoven fabric manufacturing process, and the fineness Is appropriately selected in consideration of the ease of selection of a solvent or a decomposer used for the chemical treatment.

The obtained ultrafine fiber bundle-forming fiber is subjected to processing steps such as drawing, heat setting, crimping, cutting, and fiber opening by a conventionally known method to produce raw cotton. Such raw cotton is defibrated with a card and formed into a random wave or a cross wrap wave with a weber. The waves are laminated as needed to achieve the desired weight. The weight of the wave depends on the intended use, but is generally 100-300.
A range of 0 g / m ² is desirable. The ultrafine fiber bundle-generating fiber may be mixed with an ultrafine fiber bundle-generating fiber containing no elastic fiber component as long as the effect of the present invention is not impaired. In this case, the mixing amount is in the range of 95/5 to 5/95, preferably 85/15 to 30/70 in terms of the ratio of the entire inelastic microfine fiber component to the elastic microfine fiber component.

Next, a fiber-entangled nonwoven fabric is formed by performing a fiber-entanglement treatment by a known means. Preferred entanglement treatments are a needle punching method and / or a high pressure water jet method. The number and conditions of the needle punches differ depending on the shape of the needle used and the thickness of the wave, but are generally 200 to 2500 punches / hour.
It is set in a range of cm ^2. If the conditions of the needle punching are too strong, the cutting of the fibers will increase rather than the entanglement effect of the fibers, resulting in structural destruction, an increase in the wave area, and a decrease in physical properties such as tear strength.
In addition, if the entanglement is insufficient, physical properties such as peel strength are deteriorated and the appearance of the nap fiber is insufficient due to insufficient nap fiber.

In order to impart sufficient elasticity to the suede-like artificial leather obtained in the present invention and obtain flexibility, and to obtain sufficient raised fibers when subjected to a raising treatment, the fiber-entangled nonwoven fabric must be shrunk. Must. The degree of shrinkage is such that the area shrinks by 10% to 80% with respect to the area of the nonwoven fabric before the shrinkage treatment. This shrinking treatment must be performed under the condition that the elastic fiber component shrinks more than the inelastic fiber component that is the island component. In general, elastic polymers have a tendency to shrink at lower temperatures than inelastic polymers. In the case of sea-island fibers in which the inelastic polymer and the island component of the elastic polymer are mixed in the same sea component, even if the shrinking treatment is performed under the condition that only the elastic polymer shrinks, the inelastic polymer is in a stretched state and shrinks as a single fiber However, in the fiber of the present invention, since two kinds of island components are divided and arranged in a block shape, the shrinkage treatment is performed under the condition that the elastic polymer shrinks more than the inelastic polymer of the island component. When performed, the fibers become bimetallic and exhibit crimping and contraction. In this state, when the sea component is removed later, the ultrafine fiber bundle of the inelastic polymer becomes loose as a tissue, and the desired elasticity and flexibility can be obtained.

[0015] As one of the modes of the final suede-like artificial leather, it is possible to include a binder resin in the fiber entangled nonwoven fabric. By adding a binder resin, the properties of the suede-like artificial leather can be changed. Therefore, the applied binder resin may be an elastic polymer or an inelastic polymer, or a polymer occupying an intermediate region between the two. However, when an artificial leather having high flexibility and elasticity is desired, it is preferable to use an elastic polymer. The impregnation amount of the binder resin is appropriately increased or decreased depending on the elastic properties of the resin and the texture of the intended final product,
100% or less, preferably 50% based on the ultrafine fiber component
The range is as follows. If the amount of the binder resin is too large, the texture becomes hard, a rubber-like resilience appears, and the elasticity is poor.

Specific examples of the elastic polymer used as the binder resin include polyurethanes such as polyester-based polyurethane, polyether-based polyurethane, polyester-ether-based polyurethane, polylactone-based polyurethane, and polycarbonate-based polyurethane, and acrylic acid or acrylate ester. Polymers or copolymers, conjugated diene polymers such as polyisoprene, polybutadiene or polymers having conjugated diene polymer blocks in the molecule, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, vinyl acetate polymer Or a polymer such as a copolymer. When a resin having a small elastic behavior is used as a binder resin, a plasticized polymer of a vinyl chloride polymer or a copolymer, polyamide or modified polyamide, ethylene-
A polymer such as a vinyl acetate copolymer can be used.

One or more of these polymers are selected and dissolved or dispersed in a solvent or dispersant that does not dissolve or remarkably swell the fibers constituting the nonwoven fabric, and this solution is impregnated into the nonwoven fabric. The order of impregnating the solution or dispersion of the binder resin into the nonwoven fabric is as follows: (1) impregnate the fiber-entangled nonwoven fabric before the shrinkage treatment; (2) impregnate the fiber-entangled nonwoven fabric after the shrinkage treatment; The impregnation may be performed in any order of removing the sea component of the fiber constituting the combined nonwoven fabric and then impregnating. However, if a firm texture of elasticity and flexibility is desired, the binder may be arranged in the order of (2). Preferably, a resin is applied. Further, in the case of performing in the order of (3), it is preferable to impregnate a temporary fixing resin such as a water-soluble resin before impregnating the binder resin, since the ultrafine fibers are not fixed by the binder resin.

As a method of coagulating the binder resin from the binder resin solution or dispersion impregnated in the fiber entangled nonwoven fabric, a method of coagulation by heat treatment, a method of coagulation by hot water treatment, and a method of coagulation by treatment in an aqueous salt solution There is a method of coagulation by treating in a non-solvent or a solvent-non-solvent mixture, but appropriate coagulation conditions may be adopted according to the characteristics of the binder resin.

The fiber-entangled nonwoven fabric with or without the binder resin is treated with a solvent or a decomposer for the sea component of the ultrafine fiber bundle-forming fiber to remove the sea component and transform into ultrafine fiber bundle. Substrate. When a solvent treatment for removing sea components is performed, the elastic polymer is often swollen by the solvent, and when the solvent is dried, a partial sticking occurs inside the microfine fiber bundle and in the fiber entangled portion. If such agglomeration does not occur, the elastic microfibers are partially agglomerated inside the microfiber bundle and at the fiber entangled portion by treatment with another suitable solvent or swelling agent or by heat treatment. The agglutination treatment includes partial agglutination inside the elastic ultrafine fiber bundle, partial agglutination between the elastic ultrafine fiber bundle and the inelastic ultrafine fiber bundle inside the ultrafine fiber bundle, and agglutination between the ultrafine fiber bundles at the fiber entangled portion. It must be avoided that the inelastic ultrafine fiber bundle is united by dissolving the elastic ultrafine fiber component, penetrating into the inelastic ultrafine fiber bundle, and resolidifying. When the inelastic ultrafine fiber bundle is bound and integrated by the elastic fiber component, the fiber bundle becomes hard, the texture of the sheet becomes hard, and an elegant nap with a suede feeling cannot be obtained. Such partial adhesion between the elastic ultrafine fibers and partial adhesion between the inelastic ultrafine fibers and the elastic ultrafine fibers improve the form stability of the sheet and the effect of preventing the fluff from falling off when the surface is raised.

Next, at least one surface of the fibrous substrate has a fiber raised surface mainly composed of ultrafine fibers. The method of forming the fiber nap can be performed by a conventionally known method such as buffing with a sandpaper, brushing of a needle cloth, or the like.
The fibrous base having a fibrous nap formed on its surface is then dyed, but may be dyed by a usual method according to the material of the resin constituting the fibrous base. The dyed suede-like fibrous substrate is subjected to conventionally known finishing treatments such as kneading, softening and brushing to obtain a suede-like artificial leather product.

The suede-like artificial leather obtained by the present invention is:
Excellent uniformity of nap fibers on the surface, flexible and stretchable,
It has a rich texture and is for clothing, shoes,
It is suitable for use in interiors and the like.

[0022]

Next, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples. In the examples, parts and% relate to weight unless otherwise specified.

Example 1 Using a side-by-side spinning apparatus, a mixture of 6 nylon chips and polyethylene mixed at a weight ratio of 1: 1 on the extruder (A) side was used, and a polyester polyurethane and polystyrene were mixed in the extruder (B). The chips were mixed at a ratio of 1: 1 and the discharge ratio was set to extruder (A): extruder (B) = 60:
Melt spinning was performed at 40 to obtain a 10 denier raw yarn. When observing the cross-sectional photograph of this yarn, the sea component is divided into two layers of polyethylene and polystyrene, as shown in Fig. 1. The sea component of polyethylene has about 280 island components of nylon, and the sea component of polystyrene is polyester-based. It was a side-by-side bicomponent fiber in which the island component of polyurethane was dispersed in about 100 islands.

Next, the conjugate fiber was stretched 2.5 times, crimped, and cut into a fiber length of 51 mm to obtain a staple having a fineness of 4 denier. Next, a wave is made with a cross wrap weber, and alternately from both sides of the web, a total of 600 punches /
Perform needle punching of cm ² , and 780 g / m
The fiber entangled nonwoven fabric of No. ² was made. This fiber entangled nonwoven fabric was shrunk by hot water of 95 ° C. by 25% in area. The shrink-treated fiber entangled nonwoven fabric was dried, and polyethylene and polystyrene as sea components of the fiber entangled nonwoven fabric were removed with hot perchlorethylene. By this sea component removing treatment, an adhesion point was formed by fusion between the ultrafine fibers of the polyester-based polyurethane and gluing at the portion where the ultrafine fibers of the nylon and the ultra-fine fibers of the polyester-based polyurethane were in contact with each other. The thickness was 1.4 mm and the weight was 525 g. / M ² of fiber substrate.

The thickness of the fiber substrate is sliced into two parts,
The sliced surface is buffed with sandpaper to a thickness of 0.
After adjusting the thickness to 55 mm, the other surface is grain size # 400
Was raised with sandpaper to obtain a fiber napped sheet. This sheet was dyed brown with a 1: 2 type gold-containing complex dye under the following conditions. Dyeing conditions Raneal Brown GG 2% owf Irgaran Yellow GRL 1% owf Leveran NKD 1 g / l Dyeing temperature 92 ° C.
As shown in Fig. 7, a soft brown suede-like artificial leather having a uniform surface and excellent elasticity was obtained.

[0026]

[Table 1]

Example 2 A mixture of 6 nylon chips and polyethylene mixed at a weight ratio of 1: 1 on the extruder (A) side by the spinning method of Example 1 was mixed with a polyester polyurethane in an extruder (B). A mixture of polyethylene chips mixed at a ratio of 1: 1 was melt-spun with an extruder (A): extruder (B) = 60: 40. Observation of a cross-sectional photograph of this yarn revealed that the composite fiber was a sea-island composite fiber in which the island component group of nylon and the island component group of polyester-based polyurethane were bisected in the sea component of polyethylene as shown in FIG. This fiber was drawn in Example 1 below.
When a trial production of a suede-like artificial leather was conducted under the same conditions as in Example 1, a soft brown suede-like artificial leather having a uniform surface and excellent elasticity was obtained as shown in Table 1 as in Example-1.

Comparative Example 1 A mixture of 6 nylon, polyester-based polyurethane and polyethylene used in Example 1 was mixed and spun at a ratio of 3: 2: 5. As shown in FIG. 3, polyethylene was a sea component and an island component. As a result, a three-component sea-island composite fiber having a fineness of 10 denier in which 6 nylon and polyurethane were randomly mixed was obtained. This fiber was stretched, crimped, cut random web, and needle punched in the same manner as in Example 1 to obtain an entangled nonwoven fabric. As a result of subjecting this nonwoven fabric to shrinkage treatment with hot water, the area shrinkage was 8%, which was low. Next, the polyethylene of the sea component was extracted with heat perchlorethylene and brushing and dyeing were performed in the same manner as in Example 1. As a result, as shown in Table 1, the texture was firm, non-stretchable, and nap fibers on the surface. Less. Observation of the state of the ultrafine fibers of the obtained sheet revealed that, besides the polyurethane ultrafine fiber component being stuck at the fiber entanglement point, the polyurethane ultrafine fiber component in which 6 nylon ultrafine fibers were mixed inside the ultrafine fiber bundle was also bonded and integrated everywhere. Was observed.

Comparative Example 2 50 parts of polyester-based polyurethane and 50 parts of polyethylene
Two-component sea-island fiber (A) in which polyethylene is the sea component, and 50 parts of nylon 6 and polyethylene 50
Parts, and a bicomponent sea-island fiber (B) in which polyethylene is a sea component is prepared by a melt spinning method, and is superposed in the drawing step so that (A) :( B) = 4: 6. Co-stretching was performed, and thereafter, a suede-like artificial leather was finished in the same manner as in Example-1. As shown in Table 1, the obtained sheet had a soft texture, but the nylon fine bundles had coarse nap, had a different color, and had a poor fluffiness.

[0030]

The suede-like artificial leather of the present invention has a low elongation stress in the elongation range where structural elongation change does not substantially occur, has elasticity, has uniform nap fibers, and has an excellent texture. It is suitable for clothing, shoes, bags, various gloves, etc.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a multicomponent fiber used in the present invention.

FIG. 2 is a schematic sectional view of a multicomponent fiber used in the present invention.

FIG. 3 is a schematic cross-sectional view of a multicomponent fiber used in the present invention.

FIG. 4 is a schematic sectional view of a multicomponent fiber used in a conventional example.

[Explanation of symbols]

 1 island component composed of an elastic polymer 2 island component composed of an inelastic polymer 3, 3 'sea component

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-194247 (JP, A) JP-A-63-12744 (JP, A) JP-A-63-264956 (JP, A) JP-A 54-1984 26302 (JP, A) JP-A-60-139879 (JP, A) JP-A-54-125771 (JP, A) JP-A-61-201086 (JP, A) JP-A-5-138789 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) D06N 3/00-3/18 D01D 5/32 D04H 3/10 D04H 3/14

Claims (2)

(57) [Claims] An ultrafine fiber bundle comprising a pair of ultrafine fiber bundles made of an elastic polymer (elastic ultrafine fiber bundle) and an inelastic polymer bundle (an inelastic ultrafine fiber bundle) is three-dimensionally entangled. A sheet-like material having naps formed on at least one surface of a nonwoven fabric, wherein the ultrafine fiber bundles have an elastic ultrafine fiber bundle partially adhered to the inside thereof and the inelastic ultrafine fiber bundle, and Suede-like artificial leather characterized by being stuck to a part of other ultrafine fiber bundle fibers. 2. A process for producing an entangled nonwoven fabric using two ultra-fine fiber bundle-generating fibers in which two sea-island structures having an island component group composed of an elastic polymer and an island component group composed of an inelastic polymer are adjacent to each other. A step of shrinking the synthetic nonwoven fabric, a step of transforming the ultrafine fiber bundle-generated fibers into ultrafine fiber bundles, a step of forming nap on at least one surface, and a step of dyeing the obtained fiber nap substrate Leather manufacturing method.