KR20070006870A - Artificial leather with silvered tone - Google Patents

Abstract

An artificial leather with a silvered tone which comprises a base layer and a coating layer (Y) formed on one side of the base layer. The base layer comprises an interlacing nonwoven fabric (X) made of bundles of microfine fibers having an average single-fiber fineness of 0.07 dtex or smaller and a polymeric elastomer (A) and a polymeric elastomer (B) each infiltrated in inner parts of the fabric (X). The interlacing nonwoven fabric (X) comprises a lower layer (XA) and an upper layer (XB). Mainly the polymeric elastomer (A) has been infiltrated in the lower layer (XA) substantially in the state of being not bonded to the microfine-fiber bundles. Mainly the polymeric elastomer (B) has been infiltrated in the upper layer (XB) substantially in the state of being not bonded to the microfine-fiber bundles. The coating layer (Y) is composed of a 1-10 mum-thick coating layer (YB) of the polymeric elastomer (B) formed on the upper layer (XB), a coating layer (YC) of a polymeric elastomer (C) formed on the coating layer (YB), and a finish layer (YE) formed on the coating layer (YC). The artificial leather with a silvered tone, which has such structure, combines an excellent appearance similar to those of natural leathers with excellent softness, flexibility, and high peel strength. ® KIPO & WIPO 2007

Description

Silver embossed artificial leather {ARTIFICIAL LEATHER WITH SILVERED TONE}

The present invention relates to a silver grain-finished artificial leather that combines the elegant appearance of natural leather with excellent softness, flexibility and high peel strength. The silver relief artificial leather can be widely used in the use of shoes, balls, bags and the like.

Recently, synthetic leather and artificial leather are widely used in all fields such as shoes, medical care, gloves, bags, balls, interiors, etc. as substitutes for natural leather. These are required to have higher quality, aesthetics, and comfortable use, and in particular, it is strongly required that the peel strength is compatible with the appearance, flexibility, and especially for shoes of elegant natural leather.

Many flexible natural leather-like sheets have been proposed. For example, a leather-like sheet manufactured by attaching a resin film reproducing natural leather-like grains to a substrate formed by impregnating and solidifying a polyurethane resin on an entangled nonwoven fabric made of ultrafine fibers of 0.1 dtex or less is proposed. It is. Although the peeling strength of such a leather-like sheet is easy for sports shoes, the surface finish layer is thick, there is no sense of unity with the base, and a natural leather-like property is not obtained. In addition, there was also a difficulty in forming a deep grain shape.

In addition, a leather-like sheet manufactured by coating a polyurethane solution on the surface of the substrate and wet coagulating to form a foam layer, followed by coloring and embossing is proposed. Such a leather-like sheet has the appearance of natural leather, but when emphasis is placed on softness and flexibility, it is difficult to obtain sufficient peel strength because a relatively small amount of soft elastic material is filled into the base. Moreover, when it is going to obtain sufficient peeling strength, since it is necessary to fill a comparatively hard elastic body in large quantity, as a result, softness and flexibility are lost. As described above, it has been very difficult to produce a leather-like sheet having both peel strength, flexibility, softness, and appearance of natural leather.

Wet solidified by impregnating a polyurethane resin on the tangled nonwoven fabric made of ultrafine fiber-generating fibers to remove one component from the ultrafine fiber-generating fibers to obtain a gas consisting of a bundle of ultrafine fibers of 0.1 dtex or less, and then A leather-like sheet obtained by performing a surface finish is proposed (see, for example, JP-A-63-5518). However, the surface of the leather-like sheet exhibited the appearance of natural leather, but the flexibility and peel strength were not sufficient.

A leather-like sheet made of the same elastic resin as the elastic resin impregnated into the base surface layer and having a surface porous layer provided in series with the base surface layer has been proposed (see, for example, Japanese Unexamined Patent Application Publication No. 11-140779). However, when the surface porous layer was formed using a soft resin in order to obtain the appearance of natural leather, it was difficult to obtain sufficient peel strength. In order to obtain sufficient peel strength, the surface porous layer is directly formed on the substrate using a relatively hard elastomer, or the surface porous layer is formed on the surface of the substrate through a high-density resin layer, and the porous coating layer is formed on the surface porous layer. It is also known to form. In such a leather-like sheet | seat, when peeling strength can be obtained when the external appearance of a natural leather tank is obtained by embossing, softness falls. On the contrary, when softness is given priority, it becomes difficult to obtain the appearance of natural leather by embossing. Moreover, when resin which is good in embossing property is used for a surface porous layer, and resin which is hard to deform | transform by embossing is used for a high density resin layer, compared with the case where the same resin is used for a surface porous layer and a high density resin layer, it is sufficient. Embossability was difficult to obtain.

In order to improve the above problem, the present inventors have proposed a leather-like sheet impregnated with a polyurethane resin that is harder to be thermally deformed than the polyurethane resin constituting the surface porous layer at the upper layer of the fibrous base layer in close contact with the surface porous layer (Japan See WO 2003-105679). However, in order to have the appearance of natural leather, it was necessary to emboss after forming the surface porous layer which consists of soft polyurethane resin. For this reason, when the surface layer was thickened, a sense of unity as a whole could not be obtained.

As described above, silver-embossed artificial leathers with excellent peel strength, smooth surface, flexibility and a clear and elegant appearance such as natural leather are still not obtained.

Disclosure of the Invention

SUMMARY OF THE INVENTION An object of the present invention is a silver embossed artificial leather having an elegant appearance and excellent softness, flexibility, and high peel strength of natural leather, and more particularly, a silver embossed artificial leather having a smooth surface, high peel strength and flexibility, and a manufacturing method thereof. Is to provide.

That is, the present invention is a tangled nonwoven fabric (X) consisting of a bundle of ultrafine fibers having an average short fiber fineness of 0.07 dtex or less, a gas layer made of a polymer elastomer (A) and a polymer elastomer (B) impregnated therein, and A silver relief artificial leather composed of a coating layer (Y) formed on one side; The tangled nonwoven fabric (X) is composed of a lower layer (X _A ) and an upper layer (X _B ), and the lower layer (X _A ) is mainly impregnated in a state in which the polymer elastic body (A) is not substantially bonded to the microfiber bundles. On the other hand, the upper layer (X _B ) is impregnated mainly in a state in which the polymer elastic body (B) is not substantially bonded to the ultrafine fiber bundles; The coating layer (Y) is composed of a coating layer (Y _B ) made of a polymer elastic body (B) having a thickness of 1 to 10 μm formed on the upper layer (X _B ), and a polymer elastic body (C) formed on the coating layer (Y _B ). It provides a silver relief artificial leather, characterized in that consisting of a coating layer (Y _C ), and a finishing layer (Y _E ) formed on the coating layer (Y _C ).

To practice the invention  Best form for

Hereinafter, the present invention will be described in detail.

Silver embossed artificial leather of the present invention is composed of a tangled nonwoven fabric (X) and a gas layer composed of a polymer elastic body (A) and a polymer elastic body (B) impregnated therein, and a coating layer (Y) formed on one side of the gas layer. . The base layer mainly consists of a lower layer (X _A ) containing a polymer elastic body ( _A ) and an upper layer (X _B ) mainly containing a polymer elastic body (B). The coating layer (Y) provided on the upper layer (X _B ) is a coating layer (Y _B ) made of a polymer elastomer (B), a coating layer (Y _C ) made of a polymer elastic body (C), and a finishing layer (Y _E ) in order from the bottom. It is composed.

The gas layer used in the present invention comprises a three-dimensional entangled nonwoven fabric (X) composed of a microfiber bundle having an average short fiber fineness of 0.07 dtex or less, preferably 0.0001 to 0.07 dtex, more preferably 0.0001 to 0.05 dtex, and It is a surface smoothing layer which consists of a polymeric elastic body (A) and a polymeric elastic body (B). When the average short fiber fineness exceeds 0.07 dtex, the feel and the smoothness of the gas layer deteriorate, and it becomes difficult to form grains uniformly by embossing. A bundle consisting of ultrafine fibers having an average short fiber fineness of 0.07 dtex or less is made by a conventionally known method. For example, it can obtain by melt | dissolving or decomposing | disassembling or removing at least 1 component from the ultrafine fiber generation fiber which consists of at least 2 types of polymers, or peeling at the interface of two components by a mechanical or chemical process. In order to make the short fiber fineness of the ultrafine fibers constituting the ultrafine fibers bundle less than 0.07 dtex, it is advantageous to use sea island type ultrafine fiber generating fibers rather than using the laminated ultrafine fiber generating fibers. In addition, the microfiber bundle and the polymer elastic body constituting the silver-embossed artificial leather of the present invention need not be substantially bonded in terms of a soft feel in the form of natural leather. In order to make it substantially non-adhesive, it is necessary to form a microfiber bundle from an ultrafine fiber generating fiber, and it is preferable to form from an island-in-sea type ultrafine fiber generating fiber.

Polymers constituting the ultrafine fibers in the ultrafine fiber-generating fibers include melt-spun polyamides such as 6-nylon and 66-nylon, polyethylene terephthalate, polybutylene terephthalate, and cationic salt modified type. At least 1 sort (s) of polymer chosen from melt spinnable polyesters, such as polyethylene terephthalate, etc. are mentioned.

The polymer to be dissolved or decomposed is different from the polymer constituting the ultrafine fiber in terms of dissolvability by a solvent or a dissolving agent, and has low compatibility with the polymer constituting the ultrafine fiber, and at the same time, ultrafine under spinning conditions. It is a polymer having a lower melt viscosity or less surface tension than the polymer constituting the fiber. For example, at least 1 type of polymer chosen from polymers, such as polyethylene, a polystyrene, a polyethylene propylene copolymer, a modified polyester, is used.

The microfine fiber-generating fibers are broken down into cards and formed into a web through a webber. The obtained web is laminated so as to have a desired weight and thickness, and then entangled by a known method such as a needle punch or a high-speed water flow to form a entangled nonwoven fabric (X). If necessary, a web or the like composed of a bundle of ultrafine fibers having an average short fiber fineness of 0.07 dtex or less may be laminated on the web. The tangled nonwoven fabric (X) is preferably surface smoothed by press treatment or the like prior to impregnation of the polymer elastic body, in terms of improving the surface smoothness of the silver embossed artificial leather obtained and forming the grain shape uniformly. The thickness of the obtained tangled nonwoven fabric (X) or the pressed tangled nonwoven fabric (X) is selected according to the use of silver embossed artificial leather and the like, and is not particularly limited. When using entangled nonwoven fabric X as a single | mono layer, it is preferable that the thickness is about 0.2-10 mm, and it is more preferable that it is about 0.4-5 mm. The density is preferably 0.15 to 0.60 g / cm 3, and more preferably 0.20 to 0.40 g / cm 3. When the density is in the above range, it is possible to impregnate an appropriate amount of the polymer elastic body, to avoid a rubbery texture, to prevent a decrease in peel strength, and to obtain a silver textured artificial embossed leather having a soft feel. Do.

Next, the entangled nonwoven fabric (X) is impregnated with a solution or dispersion of the polymer elastic body (A) and the polymer elastic body (B), and then a coating layer (Y) is formed. As the polymer elastomers (A, B and C) used in the present invention, any one conventionally used for the production of artificial leather may be used, and a known polymer elastomer can be used. Among them, polyurethane is preferably used in that a natural leather-like texture and physical properties are obtained.

Preferable examples of the polymer elastomers (A) to (C) which impregnate the entangled nonwoven fabric (X) and form the coating layer (Y) include polymer diols such as polyester diols, polyether diols, and polyester ether diols. Species or more; Organic polyisocyanate, preferably at least one of aliphatic, aromatic or alicyclic organic diisocyanates; And polyurethanes produced from chain extenders having two active hydrogen atoms such as low molecular diols, low molecular diamines, and hydrazines.

Among them, polyurethane or a polyurethane having a weight percentage (hereinafter referred to as 'N%') of 2.5 to 5% of the isocyanate nitrogen atom in the organic polyisocyanate unit present in the polyurethane relative to the total polyurethane weight is mainly Mixtures are preferred. If N% is in the above range, physical properties such as abrasion resistance and scratch resistance of the coating layer (Y) and the gas layer are good, and folded wrinkles are coarse and the texture is hard, thereby preventing artificial leather from appearing cheap. Moreover, physical properties, such as the bending fatigue resistance of artificial leather, also become favorable, and are preferable.

As the polymer elastic body (C) used for the coating layer (Y _C ) of the present invention, it is preferable to use a polyurethane that can form grains of natural leather by embossing. Examples include a hard segment mainly composed of a polymer glycol having a molecular weight of 500 to 5,000 having a hydroxy group at both terminals, 4,4'-diphenylmethane diisocyanate, and a lower alkylene glycol having 2 to 6 carbon atoms. Polyurethane or the polymer glycol of molecular weight 500-5,000 which has a hydroxyl group at both ends, an aliphatic or alicyclic diisocyanate, and the polyurethane which has a hard segment mainly consisting of organic diamine or organic acid dihydrazide. However, as long as softness, flexibility, durability, processability, porous membrane formation property, etc. are sufficient, you may use these copolymers or mixtures.

Polymer glycols having a molecular weight of 500 to 5,000 having both hydroxyl groups at both ends include polyester glycols such as polyethylene adipate glycol, polybutylene adipate glycol, polyhexamethylene adipate glycol, and polycaprolactone glycol. ; Polycarbonate glycols such as polyhexamethylene carbonate glycol; Polyether glycols such as polyethylene ether glycol, polypropylene ether glycol, polytetramethylene ether glycol, and polyhexamethylene ether glycol; And mixtures thereof. Particularly preferred are polyester glycols, polycarbonate glycols, mixed glycols of polyester glycols and polycarbonate glycols, mixed glycols of polyester glycols, polycarbonate glycols and polyether glycols.

Tetramethylene diisocyanate, hexamethylene diisocyanate, etc. are mentioned as aliphatic diisocyanate, Cyclohexane diisocyanate, 4,4'- dicyclohexyl methane diisocyanate, etc. are mentioned as alicyclic diisocyanate. Organic diamines include p-phenylenediamine, metaphenylenediamine, 4,4'-diaminediphenylmethane, ethylenediamine, propylenediamine, diethanolamine, 4,4'-diaminodicyclohexylmethane, and isophorone And diamine (isophoronediamine). Examples of the organic acid dihydrazide include adipic acid dihydrazide, sebacic acid dihydrazide, terephthalic acid dihydrazide, and isophthalic acid dihydrazide. Examples of lower alkylene glycols having 2 to 6 carbon atoms include ethylene glycol, butanediol, hexanediol, diethylene glycol and dipropylene glycol, among which ethylene glycol can form a uniform grain shape by embossing. It is preferable at the point.

0.02-1.50 mm is preferable and, as for the thickness of coating layer Y _C , 0.05-1.00 mm is more preferable. If it is in the said range, since a smooth surface can be obtained, a uniform grain shape will be formed by embossing, and it will be possible to avoid the texture like rubber | gum, and it is preferable.

The base layer, in particular the elastomeric polymer to form an elastomeric polymer and a covering layer (Y _B) impregnating the top layer (X _B) of the entangled nonwoven fabric (X) in contact with the covering layer (Y) is the same thing, that is necessary that the elastomeric polymer (B) Do. If the elastomeric polymer forming the upper layer (X _B) and the covering layer (Y _B) other, by adhesion of the base layer and the covering layer (Y) is apt to decrease the peeling.

The 100% modulus of the polymeric elastomer (B) is preferably 20 to 100 kg / cm 2, more preferably 30 to 70 kg / cm 2. In addition, the polymer elastic body (B) is preferably 30 kg / cm 2 or more higher than the polymer elastic body (C) constituting the coating layer (Y _C ), can form a dense porous structure, and is difficult to thermally deform. More preferably, 100% modulus of the polymer elastic body (B) is 30 to 60 kg / cm 2 higher than that of the polymer elastic body (C).

This prevents thermal deformation of the polymer elastic body B constituting the coating layer Y _B , particularly the upper layer X _B , when the coating layer Y _C is fixed in the thermally deformed state by embossing. This is because it maintains a bundle of ultrafine fibers while maintaining flexibility, thereby increasing the peel strength. For this purpose, it is preferable that the polymer elastic body (B) has a porous structure different from the polymer elastic body (C), for example, the polymer elastic body (B) forms a denser porous structure than the polymer elastic body (C). When observing the thickness direction cross-sections of the coating layer Y _B and the coating layer Y _C , the maximum diameter of the micropores in the coating layer Y _B and the upper layer X _B is a large hole in the coating layer Y _C (droplet type or It is preferably 1/2 or less, more preferably 1/100 to 1/2, still more preferably 1/70 to 1/5. If it is in the said range, since the porous structure of the coating layer Y _B and the upper layer X _B at the time of embossing does not collapse, it is preferable because a soft and flexible texture can be obtained. In the case where the polymer elastic body (B) does not form a porous structure, a feeling of unity of the coating layer (Y) and the gas layer by embossing cannot be obtained, and the texture tends to be inferior. The pore diameter ratio can be made within the said range by adjusting well-known methods, for example, the viscosity, a density | concentration, and also a kind of a polymeric elastic body suitably.

The polymer elastic body (B) is not particularly limited as long as it satisfies the above physical properties, but polyurethane is particularly preferably used from the viewpoint of the texture and physical properties of the silver relief artificial leather obtained. The kind of polyurethane is not specifically limited, An ester type, an ether type, a carbonate type, these copolymer type, or a mixture can be used. It is more preferable to use the ether type mainly for the soft segment and the thing mainly containing aromatic diisocyanate and aromatic diamine for the hard segment in the point which is hard to heat-deform.

For example, a soft segment containing 50% or more of polyether diol having an average molecular weight of 500 to 3,000, preferably polytetramethylene glycol, more preferably 70% or more, 4,4'-diphenylmethane diisocyanate, Polyurethanes composed of aromatic diisocyanates selected from p-phenylenediamine, metaphenylenediamine, 4,4'-diaminediphenylmethane and the like are used.

The polyurethane different from the above may be mixed with this polyurethane as needed, and the copolymerized polyurethane which consists of ether type polymer diol, polycarbonate type polymer diol, polyester type polymer diol etc. may be used.

Impregnated amount of the top layer (X _B) of the elastomeric polymer (B) is a times the fiber weight (Xb) of a top layer (X _B), 0.8~2.0 0.3~3.0 preferably by solid-fold, and more preferably. If it is in the said range, since sufficient binder effect and necessary peeling strength can be obtained, without impairing the softness of a gas layer, it is preferable.

The lower layer X _A of the entangled nonwoven fabric X is impregnated with a polymer elastic body A. Although there is no restriction | limiting in particular as a polymeric elastic body (A), Polyurethane is used preferably from the point which combines the soft texture and physical property of the natural leather form of silver-embossed artificial leather. Since the polymer elastic body (B) constituting the upper layer of the substrate is affected by heat through the coating layer (Y _C ) at the time of embossing, it is necessary to be difficult to thermally deform. However, the lower gas layer (the layer in which the polymer elastic body (A) is impregnated in the lower layer (X _A )) is more resistant to heat during embossing than the upper gas layer (the layer in which the polymer elastic body (B) is impregnated in the upper layer (X _B )). Hard to be affected by Therefore, in order to provide softness and flexibility to the base layer, the polymer elastic body (A) may be more easily thermally deformed than the polymer elastic body (B), and it is preferable to use a soft polyurethane. The 100% modulus of the polymer elastic body (A) is preferably 10 kg / cm 2 or more lower than that of the polymer elastic body (B), and more preferably 10 to 60 kg / cm 2 lower.

The polymer elastic body (A) emphasizes softness and impregnates the amount of the range which does not impair the overall feel balance. For example, with respect to the fiber weight Xa of the lower layer X _A , the solid content is preferably 0.1 to 1.5 times, more preferably 0.3 to 1.0 times impregnation. If the impregnation amount is within the above range, it is preferable to avoid the texture such as rubber, the overall feel balance is good, and the high-quality texture of the natural leather-like article with a sense of fidelity can be obtained.

Impregnating the polymer elastic body (B) impregnated in the upper layer (X _B ) and the polymer elastic body ( _A ) impregnated in the lower layer (X _A ) as much as possible in the form of a layer gives the elegant appearance of natural leather by the embossing process uniformly. It is preferable because it can be done.

The layer of the polymer elastic body (B) impregnated in the upper layer (X _B ) is also in accordance with the thickness of the base layer, but is preferably 0.01 mm to 1.0 mm, more preferably 0.05 mm to 0.6 mm. If it is in the said range, since sufficient peeling strength can be obtained without impairing the softness by embossing, and rubber elasticity does not become stronger than necessary, the low repulsion feel of a natural leather form is preferable.

In addition, the silver embossed artificial leather of the present invention can obtain the peel strength required to satisfy the following formula (1), and is sufficiently resistant to deformation during embossing, and maintains the softness sufficiently even when embossing. It is preferable because it is possible. The upper limit of the expression (1) is more preferable from the viewpoint of the balance of the texture of the silver relief artificial leather obtained that is 5.0.

[b / (Xb + b)] / [(a / (Xa + a))] ≥ 1.2

In the equation 1, b is the weight of the elastomeric polymer (B) impregnated into the upper layer (X _B), Xb is the entangled nonwoven fabric constituting the upper layer (X _B) by weight, a is impregnated with a polymer in the underlying layer (X _A) The weight of the elastic body A and Xa are the weights of the entangled nonwoven fabric which comprises the lower layer X _A.

Impregnation of the polymer elastic body into the gas layer may be performed by a known treatment method, and is not particularly limited. For example, a predetermined amount of a solution or a dispersion of the polymer elastomer (B) is applied to the surface of the tangled nonwoven fabric (X) to allow natural penetration, or is applied by rubbing with a roll or a knife, and the entangled nonwoven fabric (X). The solution or dispersion of the polymer elastomer (A) is rubbed with a roll or a knife from the lower surface to penetrate, and the excess is scraped off with a knife or the like.

Alternatively, after impregnating the solution or dispersion of the polymer elastomer (A) once in the whole of the tangled nonwoven fabric (X), the tangled nonwoven fabric (X) is compressed in the thickness direction, and immediately after that, the solution or dispersion of the polymer elastomer (B) is applied. It is also possible to penetrate using the recovery power of the tangled nonwoven fabric (X), and then scrape off excess excess of the entangled nonwoven fabric (X) with a knife. In addition, after impregnating and solidifying the polymer elastic body ( _B ) in the upper layer (X _B ), knives and the like so that the thickness of the polymer elastic body (B) on the surface of the tangled nonwoven fabric (X) after the embossing becomes a layer of 1 to 10 μm By scraping off, the coating layer Y _B and the gas layer can be produced simultaneously. The coating layer Y _B and the gas layer may be manufactured separately as described below. If the thickness of the coating layer Y _B is within the above range, the texture can be avoided to be rubbery, and sufficient peel strength and good smoothness can be obtained.

In the method for forming the coating layer (Y _B ) and the coating layer (Y _C ), the polymer is continuously formed on the upper layer (X _B ) before the polymer elastic body (A) and the polymer elastic body (B) impregnated in the tangled nonwoven fabric (X) are solidified. A solution or dispersion of the elastomer (B) and the polymer elastomer (C) is sequentially applied, and finally, all polymer elastomers are solidified in the coagulating solution, and the polymer elastomer (A) and the polymer elastomer impregnated in the tangled nonwoven fabric (X). After solidifying (B) in the coagulation solution and drying, a solution or dispersion of the polymer elastomer (B) and the polymer elastomer (C) is sequentially applied on the upper layer (X _B ), and then the polymer elastomer (B) is applied. ) And the polymer elastomer (C) in a coagulating solution. The former method is preferable considering the adhesion between the base layer and the coating layer (Y). The close contact between the gas layer and the coating layer (Y) means that the surface of the gas layer (the surface of the upper layer (X _B )) and the surface of the coating layer (Y _B ) are continuously and simultaneously bonded to the entire surface without passing through substantially different layers and materials. It refers to a state and is distinguished from a partially encountered state. The partially contacted state is a state in which the surface of the base layer and the coating layer are adhered to each other, for example, when a gravure roll coating of a polymer elastomer solution or the like is applied to the surface of the base layer, and a coating layer is attached and compounded. The state where the base layer surface and the coating layer are dry bonded by an adhesive made of a crosslinked polymer elastomer.

The method of solidifying a polymer elastomer includes a method of wet solidification by immersion in a liquid containing a non-solvent of a polymer elastomer, or a method of drying and gelling a gel, followed by heat drying. The wet coagulation method is preferable at the point of forming and obtaining a porous structure of uniform pore diameter and distribution. Moreover, you may mix | blend additives, such as a coloring agent, a coagulation regulator, antioxidant, and a dispersing agent, with a polymeric elastic body as needed. As long as it is in the range which acquires the effect of this invention, you may add a small amount of resin, such as another polymeric elastic body.

In the case where the entangled nonwoven fabric (X) is formed of an ultrafine fiber-generating fiber, the polymer elastic body is solidified, and then the microfine fiber-generating fiber is micronized to be modified into a microfine fiber bundle. The micronization is carried out by treatment with a dissolving agent or a disintegrating agent to remove at least one component, or by peeling at the interface of two components by mechanical or chemical treatment. In the silver embossed artificial leather of the present invention, the microfine fiber bundle and the polymer elastic body are preferably in a state in which they are not substantially bonded. When the polymer elastic body is impregnated and solidified after the micronization, the polymer elastic body adheres to the microfiber bundle and the texture tends to be hard. Therefore, the polymer elastic body is preferably micronized after application of the polymer elastic body. In the case of miniaturization before the polymer elastomer is applied, it is preferable to provide a polymer elastomer after dissolving and removing the filler, such as polyvinyl alcohol, to prevent the microfiber and the polymer elastomer from adhering, and then remove the filler. . `` The state where the microfiber bundle and the polymer elastic body are not substantially bonded '' means that the solidified polymer elastic body around the microfiber bundle does not adhere to the microfiber bundle at the intersection of the microfiber bundle and the difference between the microfiber bundles. The state in which a space | gap exists between and a solidified polymer elastic body is said.

After forming the coating layer (Y _B ) and the coating layer (Y _C ) on the surface of the base layer, by forming the finishing layer (Y _E ) on the coating layer (Y _C ) by the following method, the appearance of the natural leather of the present invention Having silver embossed artificial leather can be obtained. Inks consisting of colorants such as pigments and dyes and known finishing resins are applied by methods such as gravure rolls, reverse rolls, screens, etc. to coat the surface of the coating layer (Y _C ), and grain shape of natural leather by embossing roll processing or the like. To give. In order to give the appearance of a natural leather bath by embossing, it is preferable that the heating temperature of an embossing roll is 100-230 degreeC. If it is in the said range, since a uniform grain shape is formed and a polymeric elastic body in a gas layer does not thermally deform, it is preferable. The press pressure of the embossing roll is preferably in the range of 0.5 to 15 kg / cm 2. If within this range, is a uniform grain shape is formed, and the lower layer (X _A) is compressed is preferred to be able to avoid that the texture becomes hard. Since the obtained artificial leather combines softness, flexibility, and appearance of natural leather, it is more preferable that the heating temperature is 120 to 190 ° C and the press pressure is 1 to 6 kg / cm 2. The silver embossed artificial leather thus obtained has a clear grain shape, high-quality appearance and excellent softness, flexibility and a sense of fidelity of natural leather.

After embossing, a relaxation treatment is performed by a mechanical wrinkle treatment or a liquid dyeing machine, so that natural wrinkle wrinkles can be entered, and the flexibility and the quality of natural leather can be further improved. In addition, by applying a resin that can be dyed during gravure coloring and dyeing with a dyeing machine after embossing, a transparent appearance, a natural shrink, etc. can be obtained, and furthermore, the flexibility is further enhanced. You can get it.

In the silver relief artificial leather of the present invention obtained as described above, the thickness of the gas layer is 0.2 to 10 mm, the thickness of the upper layer (X _B ) is 0.01 to 1.0 mm, and the thickness of the coating layer (Y _B ) is 1 to 10 μm. It is preferable that the thickness of the coating layer Y _C is 0.02-1.50 mm, and the thickness of the finishing layer Y _E is 1-100 micrometers.

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. In addition, "part" and "%" in an Example are a basis of weight unless there is particular notice.

(1) single fiber fineness

From the micrograph of a fiber bundle cross section, the number of the ultrafine fibers which comprise a fiber bundle was counted. The value obtained by dividing the total fineness of the fiber bundles by the number was the short fiber fineness.

(2) thickness of coating layer (Y _B )

The artificial leather was cut in the thickness direction, and the cut surface was photographed with a scanning electron microscope. Entangling the lower part (cover layer (Y _B of the upper part of the fibers constituting the top layer (X _B) of the nonwoven fabric (X) (the portion close to the coating layer (Y _B)) coating layer (Y _C) from the bundle to the average of 10 point lines ) closest to the portion) of a distance to the average of 10 points enclosed line to a thickness of the coating layer _(B Y).

(3) Porous structure of coating layer (Y _B ) and top layer (X _B ) and coating layer (Y _C )

Cutting the leather-like sheet in the thickness direction, and a cover layer (Y _B) and the top layer (X _B) and the coating layer _(C Y) each cross section of the porous layer state was photographed with a scanning electron microscope. The diameters of the micropores in the coating layer Y _B and the upper layer X _B and the macropores of the coating layer Y _C (for example, droplet or bottle shape) and their dispersion state are checked, and the coating layer Y _B and it was judged that the porous structure is not different from the top layer (X _B) and the covering layer (Y _C). In addition, from the scanning electron micrograph, the micropores of the coating layer Y _B and the upper layer X _B and the macro holes of the coating layer Y _C (non-circular holes such as water droplets or flasks) have a thickness direction and Ten points of diameters (measured to short diameters) in the vertical direction were selected, respectively, and their average values were respectively defined as the maximum hole diameters.

(4) Calculation of [b / (Xb + b)] / [(a / (Xa + a)]

The coating layer (Y) of silver relief artificial leather was sliced off. The remaining gas layer was observed with an electron microscope, and the interface between the polymer elastomer (A) and the polymer elastomer (B) in the gas layer was confirmed. According to the interface, the gas layer was sliced and separated into an upper layer and a lower layer. And the weight, upper layer (Xb + b), and lower layer (Xa + a) of each slice piece were measured. Next, the slice pieces were washed separately in the solvent of the polymer elastomer (A) and the polymer elastomer (B) (DMF in the case of polyurethane), and the polymer elastomer was removed and dried to measure the weight (Xb and Xa). Then, b and a were obtained by subtracting Xb and Xa from previously measured Xb + b and Xa + a. The value of the said formula was computed from the obtained weight.

(5) peel strength

Silver embossed artificial leather was cut to a width of 2.5 cm, pasted to a rubber plate using a polyurethane-based adhesive including a crosslinking agent, pressed, dried, and cured at 25 ° C. for 24 hours. Artificial leather and a rubber plate were gripped and tensioned by a tensile tester (tensile speed 100 mm / min, recording paper speed 50 mm / min), and the average value of the peel strength was read from the recording paper. This average value was divided by 2.5 and expressed in kg / cm.

Example 1

50 parts of polyethylene as sea component and 50 parts of 6-nylon as island component were melt spun in the same melting system to prepare a composite fiber having a fineness of 10 dtex. This composite fiber was stretched by 3.0 times, crimped, and cut to a fiber length of 51 mm to obtain a staple. The staples were resolved on the card and then made web on a crosslap webber. Next, a needle punch was carried out to obtain an entangled nonwoven fabric (X1) having a weight of 650 g / m 2 per unit area.

After impregnating the tangled nonwoven fabric (X1) with 13% dimethylformamide solution (polyurethane A solution; 100% modulus of the mixed polyurethane: 40 kg / cm 2) of the mixture of the polyether-based polyurethane and the polyester-based polyurethane, The knife was pressed firmly to compress up to 90% of the nonwoven thickness. Immediately thereafter, a polyester-based polyurethane having N% of 4.0 obtained by polymerizing polyethylenepropylene adipate glycol, 4,4'-diphenylmethane diisocyanate (MDI) and ethylene glycol (EG) on the surface of the tangled nonwoven fabric (X1). A 25% dimethylformamide solution (Polyurethane B solution; 100% modulus of polyurethane: 70 kg / cm 2) was applied and the entangled nonwoven fabric (X1) was made using the suction force accompanying the solution's permeability and recovery from the compressed state. The upper layer was impregnated. A part of the polyurethane (B) solution layer covering the surface of the tangled nonwoven fabric (X1) was scraped off with a knife so that the thickness after coagulation was 12 µm to form a coating layer (Y _B ). In order to form the coating layer (Y _C ), the surface of the coating layer (Y _B ) contains polyhexacarbonate glycol, polymethylenepropylene adipate, and methylenediamine in a weight ratio of 5: 2: 3, n-hexane diisocyanate, MDI , After applying 18% dimethylformamide solution (polyurethane C solution: 100% modulus of polyurethane: 40 kg / ㎠) of polycarbonate-based polyurethane copolymerized with EG, the coagulation bath of DMF / water = 30/70 Each polyurethane was solidified in the inside to form each layer having a porous structure. Subsequently, after washing with water, the polyethylene was extracted and removed to convert the composite fibers into a 6-nylon microfiber bundle composed of microfibers having an average short fiber fineness of 0.007 dtex.

A coating layer (Y _C) 5 g / ㎡ finishing layer (Y _E) of the polyurethane solution containing a brown pigment on the surface of the gravure roll coating, and the solid content of the form. Subsequently, embossing was performed at a press pressure of 2 kg / cm < 2 > for 30 seconds at 150 deg. In addition, wrinkles were wrinkled to obtain silver relief artificial leather having a natural appearance and a soft feel.

Obtained had a thickness of the base layer of the leather-like sheet is 1.3 ㎜ relief, the thickness of the top layer (X _B) is 0.15 ㎜, Xb / b was 50/50, Xa / a is 60/40, the value of equation (1) is 2.5. The thickness of the coating layer Y was 0.2 mm, the thickness of the coating layer Y _B was 8 µm, and the thickness of the coating layer Y _C was 0.18 mm. The ratio of the largest hole diameter of the coating layer Y _B and the upper layer X _B and the largest hole diameter of the coating layer Y _C was 1/25.

In addition, the peel strength of the silver relief artificial leather was 3.3 kg / cm, which greatly increased the peel strength required. The shoe was manufactured using the embossed artificial leather, and it was found to combine the elegant appearance, excellent softness, flexibility and high peel strength of the natural leather.

Example 2

Microfiber-generating fibers having a fiber length of 51 mm and a fineness of 4.0 dtex from a composite spun fiber composed of 35 parts of polyethylene (sea component) and 65 parts of 6-nylon (fiber component) having a number of island components of 50 degrees. A) was produced. Further, 50 parts of polyethylene (sea component) and 50 parts of 6-nylon (degree component) are melt-spun, drawn, and cut in the same melting system to form a microfiber-generating fiber having a fiber length of 51 mm and a fineness of 4.0 dtex (B). ) Was produced. After the microfiber-generating fibers (A) and microfiber-generating fibers (B) were carded out, respectively, a web (Wa) and a web (Wb) having a weight of 350 g / m 2 per unit area were produced in a cross-lap webber. The web Wa and the web Wb were polymerized and needle punched using a needle of 1 barb to obtain an entangled nonwoven fabric having a weight of 650 g / m 2 and a density of 0.15 g / cm 3 per unit area. After heating this nonwoven fabric to 150 degreeC, the surface was smoothed by the heat roll and the heat-entangled woven nonwoven fabric (X2) of 600 g / m <2>, density 0.30 g / cm <3>, and thickness 2.0mm per unit area was obtained. Both surfaces of the tangled nonwoven fabric (X2) mainly consisted of microfiber-generating fibers (A) and microfiber-generating fibers (B), respectively, and the inside of the nonwoven fabric was a structure in which each microfiber-generating fibers were entangled.

After the polyurethane (A) solution used in Example 1 was impregnated into the tangled nonwoven fabric (X2), the knife was pressed tightly to the web Wa side and compressed to 90% of the nonwoven thickness. Immediately thereafter, the polyurethane (B) solution used in Example 1 was applied to the web (Wb) side, and the entangled nonwoven fabric (X2) was made using the suction force accompanying the permeability of the polyurethane (B) solution and recovery from the compressed state. The upper layer portion (mainly formed from the web Wb) was impregnated. A part of the polyurethane (B) solution layer covering the surface of the tangled nonwoven fabric (X2) was scraped off by knives so that the thickness after coagulation was 12 µm to form a coating layer (Y _B ). In order to form the coating layer (Y _C ), the polyurethane (C) solution used in Example 1 was applied to the surface of the coating layer (Y _B ), and then each polyurethane was solidified in a coagulation bath of DMF / water = 30/70. Each layer having a porous structure was formed. The upper layer part (web Wb side) of the obtained gas was mainly impregnated with polyurethane (B), and the lower layer side (web (Wa side)) was mainly impregnated with polyurethane (A).

After washing with water, the polyethylene was extracted and removed from the composite fiber, and 6-nylon microfiber bundles (upper layer (X _B )) composed of microfibers having a single fiber fineness of 0.0001 dtex and 6- microfibers having a single fiber fineness of 0.07 dtex Nylon microfiber bundles (lower layer (X _A )) were converted.

Then, in the same manner as in Example 1, silver embossed artificial leather having a natural appearance and a soft feel of natural leather was obtained.

The thickness of the base layer of the obtained silver relief artificial leather was 1.4 mm, the thickness of the upper layer (X _B ) was 0.3 mm, Xb / b was 50/50, Xa / a was 60/40, and the value of Equation 1 was 2.5. The thickness of the coating layer Y was 0.15 mm, the thickness of the coating layer Y _B was 7 µm, and the thickness of the coating layer Y _C was 0.13 mm. The ratio of the largest hole diameter of the fine hole diameter of the coating layer Y _B and the upper layer X _B and the maximum hole diameter of the coating layer Y _C was 1/20.

In addition, the peel strength of the silver relief artificial leather was 2.8 kg / cm, significantly exceeding the required peel strength. Folded grain was fine, close to natural leather. The sports shoes were manufactured using embossed artificial leather, which combines the elegant appearance, excellent softness, flexibility and high peel strength of natural leather.

Example 3

The silver relief was carried out in the same manner as in Example 1 except that a part of the polyurethane (B) solution layer covering the surface of the tangled nonwoven fabric (X1) was scraped with a knife to form a coating layer (Y _B ) so that the thickness after solidification was 4 μm. Obtained artificial leather. The obtained silver relief artificial leather had the natural appearance and soft feel of a natural leather tank, and the thickness of the coating layer Y _B was 1 micrometer. Peeling strength was 2.9 kg / cm, and greatly exceeded peeling strength required. The sports shoes were manufactured using silver artificial leather, which combines the elegant appearance, excellent softness, flexibility and high peel strength of natural leather.

Comparative Example 1

All of the polyurethane (B) solution covering the surface of the tangled nonwoven fabric (X1) is scraped off with a knife so as not to form the coating layer (Y _B ), so as to form a coating layer composed of only the coating layer (Y _C ) and the finishing layer (Y _E ). A silver-embossed artificial leather was obtained in the same manner as in Example 1 except for the above. The gas layer consists of a bundle of 6-nylon microfibers of 0.007 dtex, polyurethane (A) and polyurethane (B), the upper layer (X _B ) having a thickness of 0.15 mm, and both Xb / b and Xa / a having 60 / 40, and the value of Equation 1 was 1.

In addition, the appearance was made of natural leather, but the fibers of the surface portion were fixed by polyurethane, and it was a hard texture. In order to improve the texture, the wrinkle treatment was further performed with a wrinkle, but the texture without the unity of the wrinkled coating layer and the gas layer was obtained. The peel strength was low (2.2 kg / cm) and did not become suitable for sports shoes.

Comparative Example 2

Silver embossed artificial leather was obtained in the same manner as in Example 1 except that the coating layer (Y _C ) was formed using a polyurethane (B) solution. The peeling strength of the obtained silver-embossed artificial leather was 2.8 kg / cm or more, and the touch was soft, but the grain shape of the natural leather-like leather was not obtained, and the sense of quality was insufficient. Sports shoes were manufactured using silver artificial leather, which had sufficient flexibility and peel strength, but lacked the elegant appearance and lack of luxury.

Comparative Example 3

Except that the tangled nonwoven fabric (X2) obtained in Example 2 was impregnated with a solution of polyurethane (A), the polyurethane solution (A) covering the surface was removed with a knife, and the polyurethane (C) solution was applied to the surface. In the same manner as in Example 2, silver relief artificial leather was obtained. The obtained silver relief artificial leather was wrinkled again with a wrinkle to show the natural appearance and flexibility of the natural leather, but the peel strength was low (1.8 kg / cm) and it could not be used for sports shoes.

Comparative Example 4

In the same manner as in Example 1, except that a portion of the polyurethane (B) solution layer covering the surface of the tangled nonwoven fabric (X1) was scraped with a knife to form a coating layer (Y _B ) so that the thickness after coagulation was 18 µm. Got relief artificial leather. The obtained artificial leather was assistance is 14 ㎛ thickness of the coating layer _(B Y). And although the natural appearance of the natural leather tank was obtained, it had a texture like a rubber | gum. The peeling strength requested | required was not acquired, and the coating layer Y _B and the coating layer Y _C peeled between layers.

The silver embossed artificial leather of the present invention combines the elegant appearance, smooth surface, excellent flexibility, and high peel strength of natural leather. The silver embossed artificial leather of the present invention is excellent in the high-quality appearance, flexible, unitary texture and peel strength of natural leather having a clear grain shape, and can be widely applied to sports shoes, balls and bags.

Claims (6)

An entangled nonwoven fabric (X) consisting of a bundle of ultrafine fibers having an average short fiber fineness of 0.07 dtex or less, a gas layer composed of a polymer elastic body (A) and a polymer elastic body (B) impregnated therein, and one side of the gas layer. A silver relief artificial leather composed of the formed coating layer (Y), The tangled nonwoven fabric (X) is composed of a lower layer (X _A ) and an upper layer (X _B ), and the lower layer (X _A ) is mainly impregnated in a state in which the polymer elastic body (A) is not substantially bonded to the microfiber bundles. In addition, the upper layer (X _B ) is impregnated mainly in a state in which the polymer elastic body (B) is not substantially bonded to the ultrafine fiber bundles; The coating layer (Y) is composed of a coating layer (Y _B ) made of a polymer elastic body (B) having a thickness of 1 to 10 μm formed on the upper layer (X _B ), and a polymer elastic body (C) formed on the coating layer (Y _B ). Silver embossed artificial leather, characterized in that consisting of a coating layer (Y _C ) and a finishing layer (Y _E ) formed on the coating layer (Y _C ). The method of claim 1, Silver relief artificial leather with a coating layer (Y _B ) and a coating layer (Y _C ) having a porous structure. The method of claim 2, Silver embossed artificial leather with a different porous structure between the coating layer (Y _B ) and the coating layer (Y _C ). The method according to any one of claims 1 to 3, Silver relief artificial leather that satisfies Equation 1 below: [Equation 1] [b / (Xb + b)] / [a / (Xa + a)] ≥ 1.2 In the above, b is the weight of the polymer elastomer (B) impregnated in the upper layer (X _B ), Xb is the weight of the tangled nonwoven fabric constituting the upper layer (X _B ), a is a polymer elastomer (A) impregnated in the lower layer (X _A ) ), And Xa is the weight of the tangled nonwoven fabric constituting the lower layer (X _A ). The method according to any one of claims 1 to 4, Silver relief artificial leather that satisfies Equation 2 below: MD _B -MD _C ≥ 30 kg / ㎠ In the above, MD _B is 100% modulus of the polymer elastomer (B), MD _C is 100% modulus of the polymer elastomer (C). The method according to any one of claims 1 to 5, Silver relief artificial leather satisfying the following equation: MD _B -MD _A ≥ 10 kg / ㎠ In the above, MD _B is 100% modulus of the polymer elastomer (B), MD _A is 100% modulus of the polymer elastomer (A).