JP2015030265A - Split leather and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a split leather closely resembling a skinned leather even in not only appearance and flexibility but wrinkling when folded and having high crumpling resistance available for an industrial material.SOLUTION: A split leather 1 has a filling layer 4 and a skin layer 5 sequentially laminated on the surface of a split leather 2. The density of the split leather 2 is 0.6-1.1 g/cm, and a bulky filler containing resin 3 is selectively filled into depressions existing on the surface of the split leather 2. The filling layer 4 having a thickness of 10 μm or less is a layer formed of a polyurethane resin, and the skin layer 5 is a layer formed of a polyurethane resin.

Description

  The present invention relates to a split leather obtained by laminating a skin tone surface layer on floor leather, and a method for producing the same. More specifically, the present invention relates to a split leather having a texture like a leather with silver and a high level of stagnation resistance, and a method for producing the same.

  Genuine leather is used as a high-quality material in various fields such as clothing, bags, shoes, interior materials, and vehicle interior materials. In particular, those with a surface called a silver surface are unique in appearance (gloss, texture, smoothness, etc.), texture and touch (flexibility, elasticity, swelling, slimy feeling, etc.), and wrinkles when folded. The texture (so-called “leatherness”) is favorably accepted by consumers.

  Animal skin as a raw material for genuine leather is composed of a plurality of layers having different tissue structures, specifically, an epidermis layer, a dermis layer, and a subcutaneous tissue. Of these, the remaining dermis layer from which the epidermis layer and subcutaneous tissue have been removed is wrinkled and used as leather. In addition, “tanning” is a process that fixes and stabilizes the skin tissue composed of collagen fibers, imparts durability (heat resistance, rot resistance, chemical resistance, etc.) and leatheriness, and does not wrinkle Is called “skin”, and the leather is distinguished by “leather”.

  The dermis layer can be further divided into a nipple layer and a reticulated layer. The nipple layer has a structure in which fine collagen fiber bundles are densely packed. The surface of the nipple layer after removing the skin layer is a portion called a silver surface, and this state greatly affects the value of the leather. On the other hand, in the mesh layer, thick collagen fiber bundles are irregularly branched and entangled roughly three-dimensionally. The dermis layer is usually used by dividing it into an appropriate thickness depending on the application, and the one obtained by wrinkling the skin on the side having the silver surface (mainly consisting of the nipple layer) is called leather with silver. What is obtained by wrinkling the skin on the flesh side (subcutaneous tissue side), which has no face, is called floor leather, and mainly consists of a net-like layer. And what finished the surface of the leather with silver is finished and distributed as a luxury product. In addition, a leather with silver is a general term for leather having a silver surface and various finishes utilizing the silver surface on the silver surface.

  On the other hand, floor leather which is inferior to leather compared with leather with silver has a low commercial value and can be obtained at low cost. On this floor leather, a leather surface layer made of synthetic resin is laminated and finished as if it were leather with silver, so-called split leather may be used as an alternative to leather with silver. is there.

  Since the floor leather is mainly composed of a net-like layer having a rough fiber structure, a satisfactory product cannot be obtained even if the finishing method for leather with silver is used as it is. For example, even if the resin liquid is applied directly to the floor leather, the resin liquid penetrates into the interior and the flexibility is impaired.

  Therefore, most of the conventional products are manufactured by a method called “release paper transfer method”. In this method, first, a resin liquid is applied onto a release paper having a concavo-convex pattern resembling a texture on a silver surface, and dried to form a skin layer. Next, the obtained skin layer is bonded to the floor leather through an adhesive. Finally, the release paper is peeled off to obtain a split leather having a silver surface skin layer and floor leather.

  However, the split leather thus obtained has a rubber-like finish and has a strong artificial feeling while using natural materials. In addition, the surface unevenness caused by the roughness of the fiber structure of the floor leather has an effect on the surface of the split leather, and there is a problem that the appearance, particularly the smoothness, is impaired. Furthermore, there was a problem that wrinkles when folded (how to put wrinkles into the skin layer when folded with the skin layer as the inner surface) differ greatly from that of leather with silver. Specifically, fine leather and fine wrinkles enter in the leather with silver, while large and rough wrinkles enter in the split leather. This is probably because the skin layer cannot follow the floor leather.

  In order to solve the problem of smoothness, it is conceivable to increase the thickness of the skin layer. However, in this case, the wrinkle tends to be worse.

  For such a problem, for example, in Patent Document 1, a buffer layer composed of a synthetic resin buffer layer, preferably a wet resin microporous layer, is interposed between the floor leather and the urethane-based resin skin through an adhesive. A split leather is described. Synthetic resin buffer layer develops a buffering effect on the delicate unevenness present on the floor leather surface and eliminates the influence on the urethane-based resin skin, thereby improving the appearance such as surface smoothness and appearance uniformity. Excellent characteristics. In addition, it is described that the presence of vertically long continuous pores formed by a wet method in the synthetic resin buffer layer facilitates the entry of good wrinkles that approximate leather.

  Patent Document 2 discloses a split leather product obtained by bonding a base material made of split leather (corresponding to “floor leather” in the present specification) and an outer skin layer using an adhesive, A split leather product is described in which the skin layer is a composite of an entangled nonwoven fabric formed from ultrafine fibers and a polymer elastic body contained therein. The entangled nonwoven fabric, like the collagen fibers in genuine leather, exerts the effect of reinforcing the physical strength, so that not only the surface appearance but also the sensitivity based on wrinkles that occur when folded is similar to that of genuine leather. Can be made. Further, it is described that an appearance similar to leather with silver can be imparted by further laminating a silver-tone resin layer on the skin layer.

  However, the one described in Patent Document 1 has flexibility due to the presence of adhesive layers in two places, between the floor leather and the synthetic resin buffer layer and between the synthetic resin buffer layer and the urethane-based resin skin. There was a problem of being damaged. Further, since the synthetic resin buffer layer is preferably composed of a wet resin microporous layer, the abrasion resistance such as sag resistance is not sufficient, and it is difficult to use it as an industrial material, for example, an interior material or a vehicle interior material. .

  Moreover, the thing of patent document 2 is what the skin layer is what is called artificial leather, and the texture is not fully utilized, although using a natural material. Even if the appearance could be brought close to the leather with silver by laminating the resin layer having a silver surface tone, the flexibility of the leather with silver could not be reproduced.

  On the other hand, split leather is also known, which has been finished by painting following the finish of leather with silver.

  For example, Patent Document 3 includes a base layer made of floor leather, a sealing layer obtained by coating a urethane coating containing an organic filler or an inorganic filler on the base layer, and a urethane coating applied on the sealing layer. Genuine leather materials suitable for automobile interior parts having a coating layer are described. The sealing layer prevents the urethane paint from penetrating into the floor leather, so that the texture is good and the adhesion with the coating layer is good, so that the wear resistance required for automobile interior parts can be secured. Have been described.

  Further, in Patent Document 4, a base coat layer, a color coat layer, and a top coat layer are provided on a floor leather surface that is smoothed by buffing after applying a stucco agent to the floor leather surface. An automotive seat leather is described. Here, the stucco agent is a sealing agent based on an aqueous urethane binder, and contains silica as a filler. If the floor leather surface is not smooth enough, the stucco application and buffing operations are repeated. In the floor leather treated in this way, the adhesion to the coating layer increases with the improvement of smoothness and moderate fluffing, so the leather for automobile seats with excellent abrasion resistance, strength, touch, aesthetics, etc. It is described that it can be obtained.

  However, none teaches any solution to the problem of wrinkles. For example, the one described in Patent Document 3 has to make the sealing layer thick when trying to improve the smoothness, and since the coating layer cannot follow the floor leather when folded, it contains large rough wrinkles. End up. In addition, the material described in Patent Document 4 is not smooth enough because the surface becomes fluffy when buffed after applying a stucco agent, and the sealing layer must be thickened to improve smoothness. When this happens, the coating layer cannot follow the floor leather, resulting in rough wrinkles. Moreover, there is a problem that a process load is applied if the stucco agent application and buffing are repeated.

JP-A-5-345384 International Publication WO2009 / 119551 Pamphlet JP 2010-82536 A International publication WO2011 / 61945 pamphlet

  The present invention has been made in view of such a current situation, and is not only the appearance and flexibility, but also very similar to leather with silver even when folded, and is an advanced material that can be used as an industrial material. An object of the present invention is to provide a split leather having stagnation resistance and a method for producing the same.

The present invention, first,
A split leather in which a sealing layer and a skin layer are sequentially laminated on the surface of the floor leather,
The density of the floor leather is 0.6 to 1.1 g / cm ³ ,
The recesses present on the surface of the floor leather are selectively filled with a bulky filler-containing resin,
The sealing layer is a layer having a thickness of 10 μm or less and made of a polyurethane resin,
The skin layer is split leather which is a layer made of polyurethane resin.
Second,
A step of selectively filling a bulky filler-containing resin into a concave portion present on the surface of a floor leather having a density of 0.6 to 1.1 g / cm ³ ;
A step of laminating a sealing layer made of polyurethane resin on floor leather and having a thickness of 10 μm or less;
Smoothing the laminated sealing layer;
A step of laminating a skin layer made of polyurethane resin on the sealing layer;
Is a split leather manufacturing method.

  According to the present invention, not only the appearance and flexibility, but also a leather with silver that is very similar to a leather with silver even when folded, and has a high level of sag resistance that can be used as an industrial material, and its production A method can be provided. Since the split leather of the present invention is excellent in sag resistance, it can be particularly suitably used as an interior material or a vehicle interior material.

It is sectional drawing which showed typically the split leather of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

The split leather of the present invention comprises a floor leather having a density of 0.6 to 1.1 g / cm ³ , a bulky filler-containing resin that is selectively filled in recesses present on the surface of the floor leather, and the floor leather. A sealing layer made of polyurethane resin and having a thickness of 10 μm or less and a skin layer made of polyurethane resin laminated on the sealing layer are provided.

A split leather 1 according to the present invention will be described with reference to FIG. 1. Floor leather 2, bulky filler-containing resin 3 selectively filled in a recess existing on the surface of floor leather 2, and laminated on floor leather 2. The sealing layer 4 made of polyurethane resin and the skin layer 5 made of polyurethane resin laminated on the sealing layer 4 are provided.
Hereinafter, members constituting the split leather of the present invention will be described in order.

Floor leather The floor leather used in the present invention is not particularly limited, and examples of raw materials include those derived from cows, horses, goats, sheep, deer, kangaroos and the like. Of these, those made of cowhide with high versatility, large area, and thickness are preferred. The raw hide that has been dried or salted to prevent decay is called raw hide, and this state is used in the leather making process.

The leather making process is roughly divided into a tanning process, a dyeing process, and a finishing process, and is further divided into the following.
Moistening process; raw leather, soaking / back splitting, lining, hair removal / lime pickling, splitting, remineralization, decalcification / fermentation, soaking, tanning, dyeing process;・ Greasing, setting-out, drying, taste-removing, staking (scrubbing, tapping), tension drying, silver peeling Finishing process: buffing, painting, ironing / embossing, polishing

  Although the individual steps are being improved, it can be said that the steps are technically determined and are well known in the art. These are basically the same whether silver leather or floor leather is produced. However, the order may be partially changed, omitted, or replaced with another process. For example, in the production of floor leather / split leather by the release paper transfer method, the finishing process, particularly the processes after painting are different from those described above. It can be said that the feature of the present invention is also in the process after coating.

  The floor skin is obtained by division in the tanning process. After removing the epidermal layer and subcutaneous tissue by lining, hair removal and lime pickling, it is divided into the silver side (mainly consisting of the nipple layer) and the flesh side (mainly consisting of the net layer). The skin on the flesh side is the floor skin. If necessary, the floor skin may be further divided in the thickness direction. In addition, it may be divided after the tanning step. What has undergone a tanning process is called “floor leather” and is distinguished from “floor leather” that has not been tanned.

  Thereafter, the floor leather obtained through the tanning process is sent to the finishing process. Buffing before painting is performed in order to smooth the surface by scraping the surface of the floor leather and to remove and uniform the elements that affect the appearance quality such as individual differences, differences in parts, and scratches. However, even after the buffing, there is a recess formed on the surface of the floor leather by the space generated between the fluffs. The depth of the recess is 10 to 200 μm. The gist of the present invention is that after filling the recesses and smoothing, laminating a sealing layer, and then laminating the skin layer by applying the same coating as the leather with silver.

  Sandpaper used for buffing is preferably 180 to 600. The buffing processing speed is preferably 3 to 8 m / min. The buffing is preferably performed a plurality of times, and it is preferable to use a coarse sandpaper for the first buffing and to use a fine sandpaper for the final buffing.

The thickness of the floor leather after passing through the buffing is preferably 1.0 to 2.0 mm, more preferably 1.0 to 1.4 mm. When the thickness is less than 1.0 mm, the gap between fibers constituting the floor leather is lost when the split leather is manufactured, and it becomes difficult to obtain the flexibility of the split leather, or the split leather is bent. At this time, since the inner diameter difference of the split leather is small, the skin layer cannot follow the floor leather, and there is a possibility that large rough wrinkles may enter.
If the thickness exceeds 2.0 mm, the flexibility of the split leather will be impaired, and the flexibility will be impaired, so the skin layer will not be able to follow the floor leather when folded, and large rough wrinkles will enter There is a risk of doing.

  The thickness of the floor leather is measured by dividing the floor leather into three equal parts in the direction parallel to the back line (vertical) and into three parts in the vertical direction (horizontal) to the back line. It is obtained by calculating an average value.

The density of the floor leather is required to be 0.6 to 1.1 g / cm ³ , and preferably 0.7 to 0.9 g / cm ³ . If the density is less than 0.6 g / cm ³ , the durability of split leather, particularly the tensile strength and tear strength, is impaired, and it cannot be used as an industrial material. If the density exceeds 1.1 g / cm ³ , the flexibility of the split leather will be impaired, and the flexibility will be impaired, so the skin layer will not be able to follow the floor leather when folded and will contain large rough wrinkles End up.

In the present invention, it is important to selectively fill a resin containing a bulky filler into the recesses present on the surface of the floor leather. Here, the “bulky filler” is a filler having a specific gravity smaller than that of the resin. Further, “selectively filling” means that the bulky filler-containing resin is applied only to the concave portions, not the entire surface of the floor leather surface. The resin whose bulkiness is increased by the bulky filler is applied only to the recesses on the floor leather surface, thereby concealing the recesses and smoothing the surface. In this way, the concave portions existing on the floor leather surface are eliminated from affecting the appearance of the split leather, and the wrinkles when the split leather is folded are very similar to fine and fine silvered leather. Moreover, since the application amount of the bulky filler-containing resin is minimized, the flexibility of the split leather is not impaired.

  The resin used for filling the concave portion is not particularly limited, and a resin generally used for genuine leather can be appropriately selected and used. Specifically, polyurethane resin is used from the viewpoint of durability, and polyacrylic resin is used from the viewpoint of flexibility.

  In addition, the form of the resin can be used regardless of whether it is solvent-free (solvent-free), hot-melt, solvent-based, or water-based. What is necessary is just to select suitably according to. Of these, an aqueous one-pack type is preferable from the viewpoint of flexibility. The one-component resin is usually marketed in the form of emulsified dispersion in water (emulsion type) or dissolved in an organic solvent, but the emulsion type is preferably used from the viewpoint of environmental burden.

  The bulky filler used in the present invention is a filler having a specific gravity smaller than that of the resin mixed with the bulky filler. Specific examples include already expanded microcapsules and leather powder.

The average particle diameter of the filler is preferably 10 to 150 μm, and more preferably 20 to 100 μm. When the thickness is less than 10 μm, the bulkiness is poor, and thus the smoothness and flexibility may be impaired. When it exceeds 150 μm, there is a possibility that the filler-containing resin does not spread sufficiently to the details of the recesses.
The specific gravity of the filler is preferably 0.03 to 0.10 g / cm ³ .
The content of the filler is preferably 10 to 20% in terms of solid content with respect to the resin.
Furthermore, the specific gravity of the filler-containing resin is preferably 0.8 to 0.95 g / cm ³ .

Resin, if necessary, within a range that does not impair the physical properties of the resin, urethanization catalyst, silane coupling agent, filler, thixotropic agent, tackifier, wax, heat stabilizer, light stabilizer, dye, Pigment, flame retardant, moisture permeability improver, crystal water-containing compound, water absorbent, moisture absorbent, foam stabilizer, antifoaming agent, antifungal agent, preservative, pigment dispersant, antiblocking agent, hydrolysis inhibitor, catalyst Further, additives such as a crosslinking agent, a smoothing agent, a matting agent, a tactile sensation improving agent, a slip improving agent, a thickening agent, an anti-tacking agent, and a leveling agent may be contained.
Further, it contains a solvent as required, and is used as a liquid resin liquid.

  As a specific method for selectively filling the concave portion of the floor leather surface with the bulky filler-containing resin, a resin layer that coats the whole surface of the floor leather surface by applying the bulky filler-containing resin liquid to the entire surface of the floor leather surface and heat-treating it. Is formed, and then buffed to scrape off excess resin from the convex portion.

  For application of the resin liquid containing the bulky filler, for example, a device such as a reverse roll coater, a roll coater, a gravure coater, a kiss roll coater, a knife coater, or a comma coater can be used without particular limitation. Especially, the application | coating by a reverse roll coater is preferable at the point of apply | coating a resin liquid to a recessed part and scraping off an excess resin liquid.

  After application of the resin solution, heat treatment is performed as necessary. The heat treatment is performed to evaporate the solvent in the resin liquid and dry the resin or cure the resin.

  In order to prevent excessive moisture evaporation of the floor leather, the heat treatment is preferably performed so that the floor leather itself does not reach a temperature of 80 ° C. or higher. Therefore, it is preferable that the heat processing temperature is 50-120 degreeC, More preferably, it is 60-100 degreeC. If the heat treatment temperature is less than 50 ° C., drying may be insufficient, and the stagnation resistance may be impaired. If the heat treatment temperature exceeds 120 ° C, the flexibility of the split leather may be impaired.

  The heat treatment time is preferably 2 to 20 minutes, more preferably 2 to 10 minutes. If the heat treatment time is less than 2 minutes, drying may be insufficient and the stagnation resistance may be impaired. If the heat treatment time exceeds 20 minutes, excessive loss of moisture from the floor leather may result in shrinkage of the floor leather, resulting in undesirable wrinkles, and loss of flexibility of the split leather.

After heat treatment, the resin layer surface is buffed to remove excess resin.
In the present invention, buffing can be performed using a buffing machine using sandpaper.
Sandpaper used for buffing is preferably 320 to 600. The buffing processing speed is preferably 3 to 8 m / min.

Sealing Layer Consisting of Polyurethane Resin The split leather of the present invention is composed of a sealing layer made of polyurethane resin and a polyurethane resin on the floor leather after the bulky filler-containing resin is selectively filled into the recesses of the floor leather surface. A skin layer is laminated in order. The sealing layer of the present invention is a resin layer provided to further smooth the surface and prevent the polyurethane resin liquid used for forming the skin layer from penetrating into the floor leather. By preventing the polyurethane resin liquid from penetrating into the floor leather, the flexibility of the split leather can be maintained well.

  The thickness of the sealing layer is required to be 10 μm or less, and preferably 1 μm or less. If the thickness exceeds 10 μm, the flexibility of the split leather may be impaired, or the flexibility may be impaired, and the skin layer may not follow the floor leather when folded, resulting in large rough wrinkles. There is. Therefore, it is preferable to form the sealing layer thinly.

From the viewpoint of strength, the sealing layer preferably has a tensile strength of 6 to 10 MPa, a tensile strain of 300 to 500%, and a tensile stress at 100% strain of 1 MPa or less.
Tensile strength, tensile strain, and tensile stress at 100% strain are measured according to JIS K7127.

  The polyurethane resin used for forming the sealing layer is not particularly limited, and a polyurethane resin generally used for leather can be appropriately selected and used. Examples thereof include the same resins as the polyurethane resin used for forming the skin layer described later.

  If necessary, a filler, a smoothing agent and other resin components may be added to the polyurethane resin as long as the physical properties of the polyurethane resin are not impaired. Moreover, it contains a solvent as required and is used as a liquid polyurethane resin liquid.

The polyurethane resin solution is preferably applied by a spray coater because a uniform and thin coating film can be formed.
The sealing layer is laminated on the floor leather by applying a polyurethane resin liquid on the floor leather and performing a heat treatment.

  In order to prevent excessive moisture evaporation of the floor leather, the heat treatment is preferably performed so that the floor leather itself does not reach a temperature of 80 ° C. or higher. Therefore, it is preferable that the heat processing temperature is 50-120 degreeC, More preferably, it is 60-100 degreeC. If the heat treatment temperature is less than 50 ° C., drying may be insufficient, and the stagnation resistance may be impaired. If the heat treatment temperature exceeds 120 ° C, the flexibility of the split leather may be impaired.

  The heat treatment time is preferably 2 to 20 minutes, more preferably 2 to 10 minutes. If the heat treatment time is less than 2 minutes, drying may be insufficient and the stagnation resistance may be impaired. If the heat treatment time exceeds 20 minutes, excessive loss of moisture from the floor leather may result in shrinkage of the floor leather, resulting in undesirable wrinkles, and loss of flexibility of the split leather.

Next, ironing is performed. Ironing is performed to further smooth the surface by applying heat and pressure to the sealing layer. By this smoothing step, a thin and smooth sealing layer can be formed.
Ironing is performed using an apparatus that heats and thickens with a smooth roll. The ironing temperature (roll temperature) is preferably 60 to 80 ° C. The pressure is preferably 30 to 50 kg / cm. The processing speed (conveyance speed) is preferably 5 to 10 m / min.

Skin layer made of polyurethane resin The skin layer is usually composed of a base coat layer, a color coat layer and a top coat layer. For industrial materials such as interior materials and vehicle interior materials, polyurethane finish is common.

The base coat layer is a resin layer for adjusting the layer thickness and assisting color adjustment.
The color coat layer is a resin layer for color adjustment.
The top coat layer is a resin layer for improving the sag resistance.
The skin layer is not necessarily composed of three layers, and a certain resin layer may also serve as another resin layer. Conversely, a further resin layer may be formed between the resin layers.

  The thickness of the skin layer is required to be 30 to 70 μm, and preferably 30 to 50 μm. When the thickness is less than 30 μm, when used for sewing or interior use, when pressed, fluff on the surface of the floor leather may float on the skin layer and the appearance may be impaired. If the thickness exceeds 70 μm, the flexibility of the split leather may be impaired, or the flexibility may be impaired, and the skin layer may not follow the floor leather when folded, resulting in large rough wrinkles. There is.

  A preferable range of the thickness of each layer is that the thickness of the base coat layer is 15 to 40 μm, the thickness of the color coat layer is 5 to 20 μm, and the thickness of the top coat layer is 10 to 20 μm.

  The polyurethane resin used for forming the skin layer is not particularly limited, and a polyurethane resin generally used for leather can be appropriately selected and used. Of these, polycarbonate polyurethane resins are preferable from the viewpoint of durability and light resistance. If it is a base coat layer or a color coat layer, an aqueous one-component resin is preferable from the viewpoint of texture, and if it is a top coat layer, an aqueous two-component resin is preferable from the viewpoint of durability.

The polyurethane resin can contain other resin components, fillers, anti-adhesive agents, colorants, matting agents, leveling agents, and thickeners as required, as long as the physical properties of the polyurethane resin are not impaired. . The topcoat layer can further contain a crosslinking agent and a tactile sensation improving agent.
Moreover, it contains a solvent as required and is used as a liquid polyurethane resin liquid.

  In order to laminate the skin layer on the sealing layer, first, a polyurethane resin solution for forming a base coat layer is applied on the sealing layer and heat-treated to form a base coat layer. Similarly, application and heat treatment are performed, and a color coat layer and a top coat layer are sequentially laminated on the base coat layer. The heat treatment conditions are in the same range as the heat treatment conditions for forming the sealing layer.

  For the application of the polyurethane resin solution, for example, a device such as a spray coater, a reverse roll coater, a roll coater, a gravure coater, a kiss roll coater, a knife coater, a comma coater, or a T-die coater is used without any particular limitation. it can. Among these, application with a reverse roll coater or a spray coater is preferable because a uniform and thin coating film can be formed. In particular, the spray coater can form a very thin coating film.

  The split leather of the present invention can be embossed, staking (squeezed, beaten), or the like as necessary. These may be performed at any timing.

The embossing is performed in order to give a concavo-convex pattern, particularly a texture pattern, to the surface of the skin layer. By providing a textured pattern called wrinkles that is unique to leather with silver, the appearance of split leather can be brought closer to leather with silver. Further, when bent, the concave portion (groove) becomes a starting point for wrinkles, and wrinkles are easily formed. The concavo-convex pattern is not limited to the grain pattern, and may be, for example, a geometric pattern, stone pattern, cloth pattern, floral pattern, polka dot pattern, character, etc. it can. For embossing, a conventional embossing device can be used without limitation. The emboss mold may be a roll (emboss roll) or a flat (emboss plate). Among these, a roll-shaped one (embossed roll) is preferable from the viewpoint of excellent continuous processability.
The embossing temperature is preferably 60 to 80 ° C. The pressure is preferably 100 to 250 kg / cm. The processing speed is preferably 3 to 8 m / min.

When a texture pattern is applied to the surface of the skin layer, the depth of the recess (maximum cross-sectional height: Pt) is preferably 90 to 140 μm, more preferably 100 to 120 μm. If the depth is less than 90 μm, the appearance of the split leather may be rubber-like, or it may be difficult to get wrinkles when folded. If the depth exceeds 140 μm, large and rough wrinkles may be formed along the recesses when bent.
Maximum cross-sectional height: Pt is one of the parameters representing the surface roughness of industrial products, and indicates the maximum height (μm) in the cross-sectional curve.
In addition, the other uneven | corrugated pattern is rarely provided by itself, and is often provided in combination with a texture pattern. Usually, a clear recess deeper than the texture pattern is provided.

Thus, the split leather of the present invention can be obtained.
The split leather of the present invention is excellent in flexibility. For example, when the BLC value is used as an index, the split leather is preferably 2.0 to 5.0 mm, more preferably 3.0 to 4.5 mm. is there. Here, the BLC value is a value obtained using a tactile sensation measuring device ST300 Laser Softness Tester (manufactured by MSA ENGINEERING SYSTEMS Ltd.), and the larger the value, the better the flexibility. When the BLC value is less than 2.0 mm, the flexibility is not sufficient, and when folded, the skin layer cannot follow the floor leather, and there is a possibility that large and rough wrinkles may enter. If the BLC value exceeds 5.0 mm, the stubborn resistance may be impaired due to excessive flexibility, or the shape retention may be poor and permanent distortion may occur.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. “Parts” in the examples are based on mass.
Each evaluation item followed the following method.

[Flexibility]
One test piece having a size of 150 mm square was collected, and a strain measurement value (BLC value) when it was pushed in with a load of 500 g was measured using ST300 Laser Softness Tester (manufactured by BLC Laser Technology Center Ltd.). Judgment was made according to the following criteria.
◎: 3.0 mm or more ○: 2.5 mm or more, less than 3.0 mm Δ: 2.0 mm or more, less than 2.5 mm ×: less than 2.0 mm

[With bowl]
The wrinkle when bent (how the wrinkle enters the skin layer when folded for 3 seconds by hand with the skin layer as the inner surface) was evaluated according to the following criteria.
◎: Fine wrinkles comparable to leather with silver enter ○: Somewhat fine wrinkles enter △: Large and coarse wrinkles enter ×: Almost no wrinkles enter

[appearance]
Formability, feeling of roughness, and smoothness were evaluated visually according to the following criteria.
◎: Good shapeability, excellent expression of wrinkles, no surface roughness, smoothness ○: Shapeability is slightly better, wrinkles are expressed, no surface roughness, smoothness,
Or, it has good moldability and excellent expression of wrinkles, has a slight surface roughness, and is slightly poor in smoothness. △: Poor shapeability and poor expression of wrinkles, but has no surface roughness and smoothness. Is good or the shapeability is slightly poor, but the surface is slightly rough and the smoothness is slightly poor. X: The shapeability is poor and the wrinkle expression is poor, the surface is rough and the smoothness is poor.

[Itching resistance]
Two test pieces are collected from each of the vertical and horizontal directions with a width of 25 mm and a length of 120 mm. Two test pieces in the same direction are superposed with the front side facing inward, and the test piece is attached with a spacing of 15 mm between the grips of a Scott type abrasion resistance tester (manufactured by Daiei Scientific Instruments). Gradually narrow the gap between the grips so that the two test pieces are open and separated from each other, apply a load after the surfaces of the test pieces are lightly touched, and keep the distance until the load reaches 9.8 N To narrow. The stroke was set to 40 mm, the state of the coating film was confirmed every 1000 times at a cycle of 120 times / minute, and the kneading operation was performed up to 6000 times.
The number of rubs where coating film peeling occurred was regarded as an evaluation of sag resistance.

[Example 1]
(1) Preparation of floor leather Adult cowhide from which the silver layer was removed was used as the raw leather. The dyeing was performed so as to have the same color as the skin layer.

(2) Buffing On the surface of the floor leather obtained in (1), using a buffing machine ("machine name ENDLESS BAND BUFFING MACHINE SN180, manufactured by ALETTI), using a 180th sandpaper, a rotational speed of 1000 rpm, After buffing once at a processing speed of 5 m / min, using a 400th sandpaper, buffing was performed once at a rotation speed of 1000 rpm and a processing speed of 5 m / min.
The obtained floor leather had a thickness of 1.2 mm and a density of 0.8 g / cm ³ .

(3) Filling recesses with bulky filler-containing resin [Prescription 1]
1) Trade name “Melio Aquabase HF”; 900 parts (bulky filler-containing polyacrylic resin, solid content 23.5%, filler type: pre-expanded microcapsules, filler average particle diameter 50 μm, filler specific gravity 0.05 g / cm ³ )
2) Trade name “Melio Resin A712”; 50 parts (polyacrylic resin, solid content 19.5%)
3) Product name “Aqualen TOP 2020A”; 50 parts (polyurethane resin, solid content 30.5%)

All raw materials are manufactured by Clariant Corporation.

According to Formula 1, each raw material was mixed with a mixer to prepare a filling paint.
The filler content relative to the resin in the paint was 15%, and the specific gravity of the whole paint was 0.85 g / cm ³ when dried.

Using the reverse roll coater (trade name “JUMBOSTAR-SR”, manufactured by Ge.Ma.Ta.SpA) on the surface of the floor leather obtained in (2), the wet coating amount is 100 g / m. ^It was applied so as to be ^2, and left in a dryer adjusted to 80 ° C. for 3 minutes for heat treatment.

(4) Buffing On the surface of the floor leather obtained in (3), using a buffing machine (“machine name ENDLESS BAND BUFFING MACHINE SN180, manufactured by ALETTI), using 400 sandpaper, rotation speed 1000 rpm, Buffing was performed once at a processing speed of 5 m / min.
The resin of the convex portion was scraped off by buffing, and the bulky filler-containing resin was selectively filled in the concave portion of the floor leather surface.

(5) Formation of sealing layer [Prescription 2]
1) Trade name “Melio Program 59”; 150 parts (polyurethane resin, solid content 32.5%)
2) Product name “Aqualen TOP 2020A”; 150 parts (polyurethane resin, solid content 30.5%)
3) Water; 750 parts

The raw materials are all manufactured by Clariant Co., Ltd. except for water.

  According to Formula 2, each raw material was mixed with a mixer to prepare a coating material for forming a sealing layer. At this time, using a cup viscometer NK-2 (manufactured by Anest Iwata Co., Ltd.), the viscosity was adjusted with a thickener so as to be 18 seconds.

Using the spray coater (trade name “TU ROT.3400 / 1.41”, manufactured by BARNINI Srl) on the surface of the floor leather obtained in (4), the coating amount for forming the sealing layer is 30 g. / M ^2, and heat-treated by leaving in a dryer adjusted to 100 ° C. for 3 minutes.

  The sealing layer had a tensile strength of 8.5 MPa, a tensile strain of 426%, and a tensile stress at 100% strain of 0.6 MPa. The measurement was performed in accordance with JIS K7127, using a film (thickness 30 μm) made from the coating material for forming the sealing layer as a test piece. The shape and dimensions of the test piece were the test piece type 2, the width was 25 mm, and the gap between chucks was 50 mm The test speed was 100 mm / min.

(6) Ironing On the surface of the sealing layer obtained in (5), using an embossing machine (trade name “KOMBIPRESS-1800NE”, manufactured by BERGI ofb spa), 70 ° C., pressure: 40 kgf / Ironing was performed at m ² and processing speed: 7 m / min, and the surface of the sealing layer was smoothed. The thickness of the obtained sealing layer was 0.5 μm.

(7) Formation of base coat layer [Prescription 3]
1) Trade name “Melio Program 59”; 50 parts (polyurethane resin, solid content 32.5%)
2) Product name “Aqualen TOP 2020A”; 150 parts (polyurethane resin, solid content 30.5%)
3) Product name “EUDERM Black B-N”; 150 copies
(Pigment, solid content 23%)
4) Trade name “Melio Mattpaste C”; 140 parts (matting agent, solid content 26%)
5) Trade name “Melio Ground BG”; 80 parts (tacking inhibitor, solid content 23.5%)
6) Trade name “Melio Wax 178”; 30 parts (tacking inhibitor, solid content 20%)
7) Product name “Reelca Wax Top B”; 40 parts (wax, solid content 15%)
8) Product name “Aqualen Top D-2019”; 70 parts (matting agent, solid content 24%)
9) Product name “Melio 03-F-95”; 300 parts (polyurethane resin, solid content 34%)
10) Trade name “Melio 02-W-53”; 100 parts (acrylic resin, solid content 35%)
11) Trade name “Melio LV-03”; 30 parts (leveling agent, solid content 10%)
12) Product name “Melio WF-5238”; 10 parts (tactile feel improver, solid content 50%)
13) Water; 100 parts

The raw materials are all manufactured by Clariant Co., Ltd. except for water.

  In accordance with Formula 3, each raw material was mixed with a mixer to prepare a base coat layer-forming coating material. At this time, it adjusted with the thickener so that a viscosity might be set to 50 seconds using cup viscometer NK-2 (made by Anest Iwata Corporation).

Using the reverse roll coater (trade name “JUMBOSTAR-SR”, manufactured by Ge.Ma.Ta.SpA) on the surface of the sealing layer obtained in (6), the base coat layer forming paint is applied in a wet coating amount. It apply | coated so that it might become 100 g / m < ² >, and it heat-processed by leaving still for 3 minutes in the dryer adjusted to 100 degreeC. The thickness of the base coat layer was 28 μm.

(8) Embossing For the intermediate product obtained in (7), using an embossing machine (trade name “KOMBIPRESS-1800NE”, manufactured by BERGI ofb spa), roll temperature 90 ° C., pressure 150 kgf / m ^2. Embossing was performed under the conditions of a processing speed of 5 m / min to give a texture pattern.
It was 114 micrometers as a result of measuring the depth (maximum cross-section height) of a wrinkle pattern.

(9) Formation of color coat layer [Prescription 4]
1) Trade name “Melio Program 59”; 50 parts (polyurethane resin, solid content 32.5%)
2) Product name “Aqualen TOP 2020A”; 70 parts (polyurethane resin, solid content 30.5%)
3) Product name “EUDERM Black B-N”; 150 copies
(Pigment, solid content 23%)
4) Trade name “Melio Mattpaste C”; 140 parts (matting agent, solid content 26%)
5) Trade name “Melio Ground BG”; 50 parts (tacking inhibitor, solid content 23.5%)
6) Trade name “Reelca Wax Top B”; 30 parts (wax, solid content 15%)
7) Product name “Aqualen Top D-2019”; 100 parts (matting agent, solid content 24%)
8) Trade name “Melio 03-F-95”; 300 parts (polyurethane resin, solid content 34%)
9) Product name “Melio 02-W-53”; 100 parts (acrylic resin, solid content 35%)
10) Trade name “Melio LV-03”; 30 parts (leveling agent, solid content 10%)
11) Trade name “Melio WF-5238”; 10 parts (tactile feel improver, solid content 50%)
12) Water; 200 parts

The raw materials are all manufactured by Clariant Co., Ltd. except for water.

  In accordance with Formula 4, each raw material was mixed with a mixer to prepare a paint for forming a color coat layer. At this time, using a cup viscometer NK-2 (manufactured by Anest Iwata Co., Ltd.), the viscosity was adjusted with a thickener so as to be 25 seconds.

Using a spray coater (trade name “TU ROT.3400 / 1.41”, manufactured by BARNINI Srl) on the surface of the intermediate product that has undergone step (8), a coating amount for forming a color coat layer is 25 g. / M ^2, and heat-treated by leaving in a dryer adjusted to 80 ° C. for 3 minutes.
The thickness of the color coat layer was 7.5 μm.

(10) Formation of topcoat layer [Prescription 5]
1) Brand name “Aqualen Top D-2019”; 150 parts (matting agent, solid content 24%)
2) Product name “Aqualen TOP 2007A”; 80 parts (polyurethane resin, solid content 20%)
3) Product name “EUDERM Black BN”; 20 copies
(Pigment, solid content 23%)
7) Trade name “Melio 09-L-37”; 100 parts (polyurethane resin, solid content 32%)
8) Product name “Melio WF-5241”; 30 parts (tactile feel improver, solid content 30%)
9) Product name “Melio WF-5238”; 70 parts (tactile feel improver, solid content 50%)
10) Product name “Aqualen Top DP-2100”; 300 parts (polyurethane resin, solid content 27.5%)
11) Trade name “Melio WF-5227A”; 20 parts (tactile feel improver, solid content 44%)
12) Trade name “Melio LV-03”; 30 parts (leveling agent, solid content 10%)
13) Water; 150 parts

The raw materials are all manufactured by Clariant Co., Ltd. except for water.

  According to the prescription 5, each raw material was mixed with a mixer to prepare a topcoat layer-forming coating material. At this time, using a cup viscometer NK-2 (manufactured by Anest Iwata Co., Ltd.), the viscosity was adjusted with a thickener so as to be 25 seconds.

Using a spray coater (trade name “TU ROT.3400 / 1.41”, manufactured by BARNINI Srl) on the surface of the intermediate product obtained in (9), the wet coating amount is 1 It apply | coated so that it may become 25 g / m < ² > in the 2nd time and the 2nd time, and it left still in the dryer adjusted to 80 degreeC for 3 minutes, and heat-processed.
The thickness of the top coat layer was 15.5 μm.
The thickness of the entire skin layer was 50.5 μm.
Thus, the split leather of Example 1 was obtained.
In addition, as a result of measuring the depth (maximum cross-sectional height) of the embossed pattern of the obtained split leather, it was 111 μm.

In Example 2 and Comparative Examples 1-2, split leather was obtained in the same manner as in Example 1 except that buffing, formation of a sealing layer, and ironing were performed according to Table 1.
Table 1 shows the wrinkle pattern depth of the split leather obtained in Examples and Comparative Examples, and the evaluation results of the evaluation items described above.

DESCRIPTION OF SYMBOLS 1 ... Split leather 2 ... Floor leather 3 ... Bulky filler containing resin 4 ... Sealing layer 5 ... Skin layer

Claims (2)

A split leather in which a sealing layer and a skin layer are sequentially laminated on the surface of the floor leather,
The density of the floor leather is 0.6 to 1.1 g / cm ³ ,
The recesses present on the surface of the floor leather are selectively filled with a bulky filler-containing resin,
The sealing layer is a layer having a thickness of 10 μm or less and made of a polyurethane resin,
A split leather, wherein the skin layer is a layer made of a polyurethane resin. A step of selectively filling a bulky filler-containing resin into a concave portion present on the surface of a floor leather having a density of 0.6 to 1.1 g / cm ³ ;
A step of laminating a sealing layer made of polyurethane resin having a thickness of 10 μm or less on the surface of a floor leather filled with a bulky filler-containing resin;
Smoothing the laminated sealing layer;
A step of laminating a skin layer made of polyurethane resin on the sealing layer;
A method for producing split leather, comprising: