JP2017031228A - Split leather and production method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a split leather having real leather-like embossed irregular creases, and to provide a production method thereof.SOLUTION: A split leather has a fiber layer having a width (W) of 1-10 μm, a length (L) of 10 μm or longer, and a ratio (L/W) of the length to the width with a gap of 2 or more, and a film layer formed on the fiber layer.SELECTED DRAWING: None

Description

  The present invention relates to split leather and a method for manufacturing the same. More specifically, the present invention relates to a split leather having wrinkles of wrinkles that are characteristic of genuine leather and a method for manufacturing the same.

  Natural leather with silver surface (so-called genuine leather) is excellent in suppleness, moisture retention, durability, and touch. As a high-quality material, interior materials for automobiles such as seats and handles, interior products such as sofas, Used in various products such as shoes and bags. However, natural leather with a silver surface has a thumbprint (brand) to indicate the owner of the cow, scratches (rose scratches), parasite loopholes (grab holes), skin damage from manure (manual) and insects. There are a lot of natural markings such as traces and wounds between cows. For this reason, in high-end products, mold making operations are performed while avoiding these natural markings, so there are many parts that are wasted, and higher value-added finishes that take advantage of nature have lower product stability and require more effort. There is a contradiction that the texture becomes artificial.

  Conventionally, synthetic leather such as PVC leather and urethane synthetic leather, and split leather are used as alternatives for natural leather with a silver surface as a lower priced leather material. Among these, the synthetic leather can have an appearance similar to that of genuine leather, but the natural leather with silver surface has no wrinkles that should be originally present, so that the texture and texture of the synthetic leather are clearly different from the genuine leather.

  As for split leather, a method of manufacturing a skin material for automobile interiors is disclosed in which a skin material made by bonding natural leather (for example, floor leather) to a polycarbonate polyurethane film surface having a wrinkle pattern on the surface is milled. (Patent Document 1). According to this method, an interior skin material having the same appearance and texture as genuine leather can be produced at low cost.

JP-A-8-81700

  However, the split leather described in Patent Document 1 has a problem that it is difficult to form wrinkles close to genuine leather.

  Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a split leather having wrinkles of wrinkles that are characteristic of genuine leather and a method for manufacturing the same.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by forming a gap having a specific shape in the floor leather, and have completed the present invention.

  Since the split leather of the present invention has wrinkles of wrinkles that are typical of genuine leather, it has an appearance, appearance, and touch (feel) close to those of genuine leather.

FIG. 1 is a partially enlarged sectional view of the split leather of the first embodiment. FIG. 2A is a diagram illustrating a method for measuring the width (W) and length (L) of the gap according to the present invention. FIG. 2B is a color diagram illustrating a method for measuring the width (W) and length (L) of the gap according to the present invention. FIG. 2C is a diagram illustrating a method for measuring the width (W) and length (L) of the gap according to the present invention. FIG. 3A is a diagram illustrating a preferred embodiment of a method for forming a gap in a fiber layer according to the present invention. FIG. 3B is a diagram illustrating a preferred embodiment of a method for forming a gap in the fiber layer according to the present invention. FIG. 4 is a diagram showing a wrinkle evaluation jig used for evaluation of appearance, appearance, and tactile sensation regarding split leathers of examples and comparative examples. FIG. 5 is a diagram showing a wrinkle evaluation jig used for evaluating wear resistance of the split leathers of Examples and Comparative Examples.

  The first of the present invention is a fiber layer having a gap having a width (W) of 1 to 10 μm, a length (L) of 10 μm or more, and a ratio of length to width (L / W) of 2 or more, and the fibers A split leather having a coating layer formed on the layer is provided. The present invention is characterized in that the gap having the specific shape is formed in a fiber layer (for example, floor leather). In normal leather with silver surface (so-called genuine leather), the silver layer floats from the interface between the silver layer (nipple layer, silver surface) and the fiber layer (network layer, floor surface, split layer). Creates the original feel and texture of genuine leather. On the other hand, since conventional split leather does not have this interface, there is a problem that wrinkles do not exist and the touch and texture close to genuine leather cannot be exhibited. In contrast, according to the present invention, by forming a gap of a specific shape between the fibers of the fiber layer (network layer), a pseudo interface is created under the coating layer, and wrinkles close to genuine leather are created. Can be generated. Moreover, since it becomes easy to bend when it pushes with a finger | toe by this clearance gap, a soft tactile sensation can be produced. Therefore, since the split leather of the present invention has wrinkles of wrinkles that are characteristic of genuine leather, it can have a touch (feel), texture, appearance, and appearance close to those of genuine leather. Further, the presence of such a gap makes it easy to bend when pressed with a finger or the like, so that a soft tactile sensation can be produced. In the present invention, even when inexpensive floor leather is used as the fiber layer, a split leather having a touch (feel), texture and appearance close to those of genuine leather can be provided.

  Embodiments of the present invention will be described below. In addition, this invention is not limited only to the following embodiment. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

  In the present specification, “X to Y” indicating a range means “X or more and Y or less”, and “weight” and “mass”, “wt%” and “mass%”, “part by weight” and “ “Part by mass” is treated as a synonym. Unless otherwise specified, measurement of operation and physical properties is performed under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50%.

[Split leather]
FIG. 1 shows a partially enlarged sectional view of split leather as a preferred embodiment of the present invention. In FIG. 1, a split leather 1 has a fiber layer 2 and a coating layer 3, and the coating layer 3 is formed on the fiber layer. In FIG. 1, the coating layer 3 is directly formed on the fiber layer 2, but is not limited to this form. For example, the coating layer 3 is formed on the fiber layer 2 via an adhesive layer. May be.

[Fiber layer]
The present invention provides a fiber layer having a specific-shaped gap having a width (W) of 1 to 10 μm, a length (L) of 10 μm or more, and a ratio of the length to the width (L / W) of 2 or more (this specification Then, it is simply characterized by forming a “gap according to the present invention” or simply “gap”. When a gap having such a specific shape is formed in the fiber layer, wrinkles are formed on the surface of the coating film layer starting from this gap, and appropriate wrinkles are formed even when folded. Due to the presence of such wrinkles, the split leather of the present invention can bring out a touch (feel), texture, appearance and appearance close to those of genuine leather. Further, the presence of such a gap makes it easy to bend when pressed with a finger or the like, so that a soft tactile sensation can be produced.

  Among the above requirements, the width (W) of the gap according to the present invention is 1 to 10 μm. Here, when W is less than 1 μm, the wrinkles are shallow, and the starting point that can form appropriate wrinkles on the coating film surface cannot be obtained, and the touch (feel), texture, and appearance close to those of genuine leather can be achieved. Also, it does not look good. On the other hand, if W exceeds 10 μm, the wrinkles will be too large and the deflection when pressed will be too large to achieve the touch (feel), texture and appearance close to those of genuine leather, and will also look good. Absent.

  The length (L) of the gap according to the present invention is 10 μm or more. Here, when L is less than 10 μm, the wrinkles are too shallow or too small to be able to form a starting point capable of forming appropriate wrinkles on the surface of the coating film, and feel close to genuine leather (tactile sensation), The texture and appearance cannot be achieved, and the appearance is not good. In addition, the upper limit of the gap length (L) according to the present invention is not particularly limited, but considering the further improvement in touch (feel), texture, and appearance close to genuine leather, the length of the gap (L ) Is preferably 10 to 100 μm.

  Further, the ratio of the length to the width of the gap according to the present invention (L / W) is 2 or more. Here, when L / W is less than 2, the entire dent is too uniform to be able to form an appropriate wrinkle on the surface of the coating film, and feels close to the leather (feel), texture. Also, it doesn't look good. In addition, the upper limit of the gap length ratio (L / W) according to the present invention is not particularly limited, but considering the further improvement in touch (feel), texture, and appearance close to genuine leather, The length ratio (L / W) is preferably 2 to 98.

  In the present invention, the fiber layer has the gap according to the present invention as described above, but the ratio of the gap in the fiber layer is not particularly limited. Specifically, the fiber layer preferably has a gap according to the present invention at an area ratio of 10% or more (upper limit: 100%). If it is such a ratio, the gap is the starting point and appropriate wrinkles are formed on the surface of the coating layer, so that the split leather of the present invention has a touch (feel), texture, and appearance close to those of genuine leather, Also, it looks great. In addition, in such a case, it is easy to bend when pressed and a soft touch can be given.

  The “width (W)”, “length (L)”, “ratio of length to width (L / W)” and “ratio in which the gap exists in the fiber layer” are measured by any method. May be. Specifically, in the present specification, the above value is measured by the following method.

<Measurement method of gap width, length, ratio of length to width and ratio of gap in fiber layer>
Below, the measuring method of the width | variety and length of the clearance gap which concerns on this invention is demonstrated, referring FIG. First, a cross section of the fiber layer is photographed with an electron microscope to obtain a black and white image (FIG. 2A). Next, the color of this monochrome image is binarized (FIG. 2B). Next, 29 gaps are selected at random from this binarized image, and for each gap, the width (W), the length (L), and the ratio of the length to the width (L / W) are measured, The average value is obtained (FIG. 2C). Further, the ratio (%) of the gap in the fiber layer is obtained from the binarized image.

  In the present invention, the fiber layer is not particularly limited, but is preferably inexpensive from an industrial viewpoint. From this point of view, specifically, leather with silver surface that is inappropriate as a product due to many natural markings, leather with silver surface remaining after mold making, floor leather (Grain Side) And fresh side (including Flesh Side). Of these, floor leather (having a net leather layer of natural leather and subcutaneous tissue) is preferably used in consideration of the ease of forming a gap, price, size of area, and the like. In addition, the floor leather can exert an effect of reinforcing the physical strength without impairing the leather-like texture by the collagen fibers intersecting vertically and horizontally contained in the mesh layer. That is, the fiber layer is preferably derived from floor leather. Here, the floor leather means a part having a reticulate layer and a subcutaneous tissue on the side having no silver surface when the skin is divided (split) into a nipple layer (silver surface) and a reticulated layer (floor surface). The method for producing floor leather is not particularly limited, and known methods can be used. For example, after removing the skin on the ventral or dorsal side of an animal, the upper surface layer from the skin epidermis to the upper part of the mesh layer and the lower layer below the upper part of the mesh layer are split (split), and then the lower layer (floor leather) It can be obtained by post-processing such as tanning, re-tanning, neutralization, dyeing, greasing, drying, buffing (buffing), pressing or the like. The lower surface (floor leather) obtained after splitting (split) is further divided in the thickness direction, so that the silver surface side including the upper layer portion of the mesh layer (the upper layer portion in the thickness direction of the mesh layer) Grain side floor leather on the nipple layer side, lower layer part of the mesh layer (layer part on the lower side in the thickness direction of the mesh layer), and fresh side floor leather on the flesh side (subcutaneous tissue side) including subcutaneous tissue can get. Here, it is preferable that the floor leather obtained is buffed on the surface of the mesh layer side. By scraping the surface of the mesh layer by buffing, the surface of the floor leather can be smoothed, and elements that affect the appearance quality such as individual differences, part differences, and scratches can be removed and uniformized.

  In the above, the splitting method is not particularly limited, and lime split (leather divided into two layers after liming treatment), wet blue split (leather divided into two layers after chrome tanning treatment), etc. Any known method can be used. The fiber layer (for example, floor leather) may be derived from any animal. For example, mammals such as cattle, sheep, goats, pigs, horses, kangaroos, elephants, rabbits, deer, cats, dogs, leopards, raccoon dogs, foxes, weasels, martens, camels, reindeer, fur seals, seals; Birds, natural leather and floor leather derived from reptiles such as sea turtles, monitor lizards, pythons and crocodiles.

  The thickness of the fiber layer is not particularly limited and is derived from a natural animal, and therefore varies depending on the type and individual of the animal to be collected, and further on the collection site. Specifically, the thickness of the fiber layer is preferably 0.6 to 3.0 mm, more preferably 0.8 to 1.6 mm. With such a thickness, the split leather (fiber layer) can be given a genuine leather-like feel and texture, and mechanical properties such as tensile strength can be sufficiently achieved.

  Although the said fiber layer may be used individually by 1 sheet, or may be used by laminating | stacking 2 or more sheets, normally 1 sheet is used independently.

[Gap Formation Method According to the Present Invention]
The method for forming the specific-shaped gap as described above in the fiber layer is not particularly limited. For example, (a) a method in which a desired fiber layer (for example, floor leather) is placed in the drum and the drum is rotated (blank method); (a) the surface of the desired fiber layer (for example, floor leather) is convex. A method of forming irregularities on the fiber layer surface by striking the shaped member (staking method); (c) placing a desired fiber layer (for example, floor leather) in the drum and rotating the drum Step) After that, the surface of the fiber layer is struck with a convex member to form irregularities on the surface of the fiber layer (staking step); and (d) the surface of the desired fiber layer (for example, floor leather) is convex. Examples include a method of striking with a shaped member and forming irregularities on the surface of the fiber layer (staking process), and then putting the fiber layer into the drum and rotating the drum (empty punching process). Of these, the method (c) is preferred. Hereinafter, although the said (c) method using floor leather as a fiber layer is explained in full detail, this invention is not limited to the following method. The method (a), (b) or (d) will be apparent from the following detailed description.

(Improve process)
As shown in FIG. 3A, in the blanking process, the floor leather is put into the drum 11 from the supply port 12, and the drum 11 is rotated. By the said process, the collagen fiber which cross | intersected the length and width contained in a fiber layer loosens, and it becomes easy to form a clearance gap in a fiber layer or a clearance gap in a fiber layer.

  In this step, the drum rotation conditions are not particularly limited, and can be appropriately selected in consideration of the ease of forming gaps in the fiber layer. Similarly, considering the ease of forming gaps in the fiber layer, the drum rotation time is preferably 3 hours or more, and more preferably 4 hours or more. Here, the upper limit of the rotation time is not particularly limited and is appropriately selected in consideration of productivity and the like, but is usually about 20 hours. The temperature in the drum is not particularly limited as long as the floor leather does not hurt, and is usually about 5 to 40 ° C, preferably about 10 to 35 ° C, and usually at room temperature (20 to 25 ° C). is there. Under such conditions, collagen fibers intersecting in the vertical and horizontal directions contained in the fiber layer are loosened moderately, and a gap is formed in the fiber layer or a gap is easily formed in the fiber layer.

(Staking process)
As shown in FIG. 3B, in the staking process, the floor leather 14 obtained in the idle driving process is inserted into the staking apparatus 13 and placed at a predetermined position. Here, as shown in the partially enlarged view of FIG. 3B, the floor leather 14 is vibrated up and down by the vibration means 16, so that the convex member 15 strikes the surface of the floor leather 14 and the floor leather surface is uneven. Is formed. As shown in the figure, a recess 17 is provided in the vibration means 16 in which the convex member 15 moves up and down. Thereby, the convex member 15 forms irregularities on the surface of the floor leather 14 by the vertical movement of the vibration means 16.

  In this step, the shape of the convex member 15 is not particularly limited, but is a columnar shape or a truncated cone shape in consideration of the shape of the gap formed in the fiber layer. Further, in consideration of difficulty in drilling, etc., as shown in FIG. 3B, it is preferable that the tip of the convex member 15 is not square and rounded. Further, the size of the convex member 15 is not particularly limited. Considering the shape of the gap formed in the fiber layer, the size of the convex member 15 is preferably 20 to 150 mm, and more preferably 30 to 80 mm. Here, the “size of the convex member 15” means the size of a portion that substantially forms unevenness on the floor leather. For example, in the case of a columnar shape, the diameter is the same as that of the truncated cone. In the case, it means the diameter (“D1” in FIG. 3B) of the portion where the roundness disappears.

  Moreover, the staking conditions in this step are not particularly limited. Considering the ease of forming gaps in the fiber layer, etc., a concave portion having a depth (“D2” in FIG. 3B) of 2 to 15 mm is formed in the floor leather 14 by the convex member 15. It is preferable. More preferably, a concave portion having a depth (“D2” in FIG. 3B) of 4 to 6 mm is formed in the floor leather 14 by the convex member 15. The vibration speed of the vibration means 16 is not particularly limited, but is preferably 60 to 600 times / minute, and more preferably 120 to 300 times / minute. In a state where the convex member 15 is inserted into the floor leather 14 so as to have the above-mentioned depth, it is preferably held for 1 minute or more, more preferably 1 minute or more and less than 3 minutes, particularly preferably 1 to 2 minutes. Under such conditions, collagen fibers intersecting in the vertical and horizontal directions contained in the fiber layer are loosened moderately, and a gap is formed in the fiber layer or a gap is easily formed in the fiber layer.

  In addition, the gap according to the present invention can be formed in the fiber layer even by the above-described blanking process or the staking process alone, but by combining the blanking process and the staking process, the book can be more efficiently and easily used. The gap according to the invention can be formed in the fiber layer.

  That is, according to the present invention, the blanking for 3 hours or more and staking for 1 minute or more are performed, and the fiber layer has a width (W) of 1 to 10 μm, a length (L) of 10 μm or more, and a length with respect to the width. There is also provided a method for producing the split leather of the present invention, which has the formation of a gap having a ratio (L / W) of 2 or more.

[Coating layer]
In this invention, a coating-film layer is formed in the said fiber layer, and, thereby, a split leather becomes a silver surface tone. The coating layer also functions as a protective layer, and the wear resistance can be improved by providing the coating layer. The coating layer may be a single layer or a laminate of two or more layers.

  Here, the coating layer / protective layer (hereinafter collectively referred to as “coating layer”) is not particularly limited, and materials conventionally used for the production of split leather coating layers are used in the same manner. it can. Specifically, cellulose ester resins such as cellulose nitrate resin, cellulose acetate resin, cellulose acetate propionate resin, cellulose acetate butyrate resin; polymer diol, organic diisocyanate, and chain extender are reacted at a predetermined molar ratio. Polyurethane resins such as polycarbonate-based polyurethane resins, polyester-based polyurethane resins, polyether-based polyurethane resins, etc .; various acrylic resins such as acrylic elastomers; polyester resins such as polyester-based elastomers, polyvinyl chloride resins And polyamide resins and copolymers thereof. Among these, considering the improvement of wear resistance, polyurethane resin and acrylic resin are preferable, and polyurethane resin and acrylic resin are more preferable. The above materials may be used alone or in the form of a mixture of two or more. The material may be a one-component type that does not require a curing agent to form a coating layer, or a two-component type that requires a curing agent to form a coating layer. Similarly, the material may be any of solvent-free (solvent-free), hot-melt, solvent-based, or water-based.

  The curing agent used in the latter case is not particularly limited, and a known curing agent can be used. Specifically, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate, lysine diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate (MDI), 1, Examples thereof include isocyanate curing agents such as 5-naphthalene diisocyanate, tolidine diisocyanate, and xylylene diisocyanate (XDI).

  The coating layer preferably contains a silicone resin (silicone oil). Thereby, the abrasion resistance of split leather can be improved. Here, it does not restrict | limit especially as a silicone resin (silicone oil), The silicone resin (silicone oil) normally used in the said field | area can be used. Specific examples include silicone oils such as dimethylpolysiloxane and methylphenylpolysiloxane; modified silicone oils such as amino-modified silicone oil. The weight molecular weight of the silicone resin is not particularly limited, but the weight average molecular weight is preferably 200 to 100,000, and more preferably 300 to 10,000. By adding such a molecular weight silicone resin to the coating layer, the wear resistance can be further improved. Moreover, if it is a silicone resin of such molecular weight, it can mix uniformly with above-described resin. As the weight average molecular weight, a polystyrene equivalent value measured by gel permeation chromatography (GPC) is adopted.

  The amount of silicone resin added when the coating layer contains a silicone resin (silicone oil) is not particularly limited. From the viewpoint of improving wear resistance, the amount of the silicone resin added is preferably 0.1 to 30% by weight, more preferably 1 to 15% by weight in terms of solid content in the coating layer. preferable. Further, when the coating layer is a laminated form of two or more layers, the silicone resin (silicone oil) may be contained in any layer, but from the viewpoint of wear resistance, the outermost layer is a smoothing agent. And a crosslinking agent are preferable.

  Instead of the above or in addition to the above, the coating layer may comprise a catalyst (for example, a urethanization catalyst), a silane coupling agent, a filler, a thixotropic agent, a tackifier, a wax, a heat stabilizer, a light-resistant stabilizer, Fluorescent whitening agent, dye, pigment, matting agent, smoothing agent, cross-linking agent, flame retardant, electrical conductivity imparting agent, antistatic agent, moisture permeability improver, water repellent, oil repellent, hollow foam, containing crystal water Including other components such as compounds, water-absorbing agents, moisture-absorbing agents, foam stabilizers, antifoaming agents, antifungal agents, antiseptics, algaeproofing agents, dispersants, inert gases, antiblocking agents, hydrolysis inhibitors Good. In this case, the other components may be used alone or in the form of a mixture of two or more. Among these, a smoothing agent and a crosslinking agent are preferable from the viewpoint of wear resistance. Here, when the coating layer is a laminated form of two or more layers, the above-mentioned other components may be included in any layer, but from the viewpoint of wear resistance, the outermost layer is a smoothing agent or It preferably contains a cross-linking agent. The amount of other components added in the case of using other components is not particularly limited as long as the physical properties of the resin are not impaired, and the same amounts as known can be used.

  The method for forming the coating layer is also not particularly limited, and a known method can be applied in the same manner or appropriately modified. Specifically, (a) A method of forming the above material (including a curing agent if necessary) into a film by various conventionally known production methods such as inflation processing, calendar processing, T-die processing; A method of forming the film by adding and mixing the above materials (including a curing agent if necessary) to a solvent, and kneading and rolling the resulting mixture with a mixing roll or the like; (c) Resin as described above And, if necessary, a method of forming a coating layer on the fiber layer by melting the curing agent and other components or adding / mixing them to a solvent and applying the obtained melt / mixture onto the fiber layer. Is mentioned.

  In the above method, the coating layer may be a single layer or a laminated film laminated with the same kind or different kinds of films. The method for obtaining a laminated film by the above methods (a) and (b) is not particularly limited, and known laminating methods can be applied in the same manner or appropriately modified. Specifically, after forming each film, a method of laminating by a dry laminating method, a heat laminating method, a method of extruding a resin to a previously formed film, a method of simultaneously forming a laminated film by a multilayer coextrusion method Etc. In the method (c), a laminate of the coating layer can be formed on the fiber layer by repeating the coating step (c).

  In the methods (a) and (c), the solvent is not particularly limited as long as the material can be appropriately dissolved or dispersed and the material is not denatured. Specifically, hydrocarbon solvents such as toluene and xylene; alcohols such as methanol, ethanol, isopropanol, butanol, and cyclohexanol; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; methyl acetate, ethyl acetate, and methyl lactate And ester solvents such as glycol ether solvents and the like. If necessary, other additives such as plasticizers, dyes, and pigments may be added in addition to the solvent.

  In the method (c), the coating method is not particularly limited, and a known method can be applied in the same manner or appropriately modified. Specifically, bar coating, die coating, gravure coating, gravure roll coating, blade coating, reverse roll coating, spray coating, knife coating, air knife coating, dip coating, roll coating, kiss roll coating, rod bar coating, calendar Examples include coating, air knife coating, and comma coating. Of these, spray coating, roll coating, and reverse roll coating are more preferable. By these coating methods, a uniform thin layer can be formed, and the shape of the wrinkles (concave / convex pattern), texture, and texture of the wrinkles that are characteristic of genuine leather in the fiber layer can be maintained as they are or as they are.

  In the above method (c), the coating layer applied to the fiber layer can be formed, for example, by evaporating the solvent in the mixture and drying the resin (heat treatment). Further, when the mixture (and hence the coating layer) contains a crosslinking agent, the solvent in the mixture is evaporated and the resin is dried, and the crosslinking treatment is promoted by the heat treatment to form a coating layer with higher strength. sell. Here, the heat treatment conditions are not particularly limited, and are appropriately selected depending on the type and amount of the resin to be used, the solvent, and other components added if necessary, and generally the same conditions as known can be applied. Specifically, the heat treatment temperature is preferably 50 to 180 ° C, more preferably 80 to 150 ° C. The heat treatment time is preferably 30 seconds to 20 minutes, more preferably 2 to 10 minutes. Under such conditions, the wrinkles (concave / convex pattern), texture and texture of the wrinkles that are characteristic of genuine leather specific to the fiber layer can be maintained as they are or as they are. Moreover, when a crosslinking agent exists, a coating layer with higher strength can be obtained.

  In addition, in the said form, when a coating film layer is a laminated | stacked form of two or more layers, each coating film layer may take the same structure or a different structure.

  Moreover, it may replace with the said coating film layer, or may form a coating film layer as a foaming layer in addition to the said coating film layer. At this time, the foamed layer is not particularly limited, but can be formed by a known method as described in JP-A-2008-265300 and JP-A-2009-297985.

  The thickness of the coating layer is not particularly limited and is appropriately selected depending on the desired effect (for example, abrasion resistance), and generally the same conditions as known can be applied. Specifically, the thickness (dry film thickness) of the coating layer is preferably 10 μm or more, more preferably 10 to 100 μm, and particularly preferably 20 to 50 μm. With such a thickness, the coating layer is uniformly formed on the fiber layer, and the wrinkles (concave / convex pattern), texture, and texture of wrinkles that are characteristic of genuine leather unique to the fiber layer can be maintained. In addition, mechanical properties such as tensile strength can be sufficiently achieved. In addition, the said "thickness (dry film thickness) of a coating film layer" means the total thickness (dry film thickness) of a coating film layer, when a coating film layer is a laminated form of two or more layers. . Moreover, when a coating film layer is a laminated | stacked form of two or more layers, the thickness of each coating film layer may be the same, or may differ.

[Use of split leather]
The split leather of the present invention has the appearance, feel and texture of a natural leather (genuine leather) with a silver surface, and is excellent in mechanical properties such as tear strength and tensile strength. Further, the split leather of the present invention needs to be sewn after the genuine leather is once immersed in water, whereas it can be directly sewn without requiring pretreatment. Therefore, the split leather of the present invention can be widely used for various applications in which natural leather with leather (genuine leather) is used. Specifically, for example, clothing, shoes, bags, miscellaneous goods, furniture (for example, chairs, sofas), vehicle interiors (for example, steering wheels, seat cushions, console armrests, assist grips, shift knobs, instrument panels), etc. It is preferably used as a leather-like material.

  The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In the following, unless otherwise specified, each operation is performed at room temperature (25 ° C.).

Example 1
Shaving the dorsal bovine hide to a thickness of 1.4 mm. Thereafter, retanning (plant tannin, synthetic tannin, naturally derived greasing agent, acrylic resin, acid dye) was performed to obtain a floor leather. Next, the floor leather obtained above is put into a drum (made by Watanabe Seisakusho, trade name: FRP drum diameter 6 × width 4), and the drum is rotated at a rotation speed of 15 rotations / minute for 4 hours. (Empty punching process). Further, the floor leather is taken out of the drum, and the surface is formed by a cylindrical convex member (diameter: 50 mm) with a rounded tip, and the depth is 4 mm at a vibration speed of 240 rotations / minute for 1 minute. By tapping (staking process), irregularities were formed on the floor leather surface to obtain a fiber layer having a thickness of 1.4 mm.

  Next, a coating layer composed of a pre-base layer, a base coat layer, a color coat layer, and a top coat layer was formed on the fiber layer as follows.

That is, first, an acrylic resin (manufactured by Clariant, trade name: Melio Resin A-946) was dissolved in water at a solid content concentration of 35% by weight to prepare a prebase. This prebase is applied on the fiber layer obtained above with a roll coater in an amount of 100 g / m ² and dried at 100 ° C. for 3 minutes to form a prebase layer (dry film thickness: 30 μm) on the fiber layer. did.

Next, polyurethane resin (product name: FINISH BB, manufactured by LANXESS) and acrylic resin (product name: HYDRHOLAC CR-15, manufactured by LANXESS) are added to water at a solid content concentration of 30% by weight and 20% by weight, respectively. A base coat (solid content concentration: 22% by weight) was prepared by dissolution. This base coat was applied on the pre-base layer obtained above with a roll coater in an amount of 100 g / m ² and dried at 120 ° C. for 3 minutes to form a base coat layer on the pre-base layer.

Furthermore, a polyurethane resin (manufactured by LANXESS, trade name: FINISH BB), an acrylic resin (manufactured by LANXESS, trade name: HYDRHOLAC CR-15) and a pigment (manufactured by Clariant, trade name: Neosan 2000 Black) are each 300. A color coat (solid content concentration: 20%) was prepared by dissolving in water at a solid content concentration of 200% by weight, 200% by weight and 1% by weight. This color coat was applied on the base coat layer obtained above by a spray coater in an amount of 28 g / m ² and dried at 120 ° C. for 3 minutes to form a color coat layer on the base coat layer.

Finally, polyurethane resin (manufactured by LANXESS, trade name: FINISH BB), acrylic resin (manufactured by LANXESS, trade name: HYDRHOLAC CR-15), silicone resin (manufactured by Shin-Etsu Silicone; trade name: KP-86; weight average) Molecular weight: 5000) and a cross-linking agent (manufactured by Clariant, trade name: Aquaren EP-70) at a solid content concentration of 300% by weight, 200% by weight, 1% by weight and 10% by weight and dissolved in water. (Solid content concentration: 28%) was prepared. This top coat is applied on the color coat layer obtained above by a spray coater in an amount of 28 g / m ² and dried at 120 ° C. for 3 minutes to form a top coat layer on the color coat layer. Split leather (1) was obtained. When the ratio of the gap in the fiber layer in the obtained split leather (1) was measured, it was confirmed that it was 10% or more.

Examples 2, 5-12, Comparative Examples 1, 3
In Example 1, the drum rotation time in the blanking process, the convex member staking time in the staking process, and the weight average molecular weight and addition amount of the silicone resin contained in the topcoat layer are shown in Table 1 below. The split leathers (2) and (5) to (12) and the comparative split leathers (1) and (3) were obtained in the same manner as in Example 1 except that the above changes were made. When the ratio of the gap in the fiber layer in the obtained split leathers (2) and (5) to (12) was measured, it was confirmed that it was 10% or more.

Examples 3-4, Comparative Example 2
In Example 1, in place of the dorsal bovine hide, the ventral bovine hide is used, and the drum rotation time in the blanking process, the convex member staking time in the staking process, and the top coat layer are included. The split leathers (3) to (4) and the comparative split leather (2) were prepared in the same manner as in Example 1 except that the weight average molecular weight and the addition amount of the silicone resin were changed as shown in Table 1 below. Respectively. When the ratio of the gap in the fiber layer in the obtained split leathers (3) to (4) was measured, it was confirmed that it was 10% or more.

  About the split leather obtained in Examples 1 to 12 and Comparative Examples 1 to 3, the width and length of the gap were measured and are shown in Table 1 below.

[Evaluation]
The split leathers obtained in Examples 1 to 12 and Comparative Examples 1 to 3 were evaluated for appearance / look and feel and are shown in Table 1 below.

(Appearance, appearance and tactile evaluation methods)
As shown in FIG. 4, each split leather (test piece) is shredded into a size of 250 mm × 250 mm, and pasted on a wrinkle evaluation jig to make a wrinkle with a depth of 25 mm. The appearance and appearance (wrinkles and gloss) are visually evaluated, and the tactile sensation is stroked by hand, and sensory evaluation is performed, and evaluation is performed according to the following criteria. In the following, 下 記 and ○ are acceptable for practicability.

(Abrasion resistance evaluation method)
As shown in FIG. 5, each split leather (test piece) 21 is shredded into a size of 250 mm × 250 mm and placed on the sample stage 22 of the traverse wear test machine 20. A friction element 23 (2 cm × 2 cm flat plate, load: 1.32 kg) is placed on the test piece 21, and the friction element 23 is summed at a reciprocating speed of 50 reciprocations per minute with an amplitude of 7.5 cm on the test piece by the motor 24. It was reciprocated 10,000 times (number of reciprocations). After reciprocating a predetermined number of times, the movement of the friction element was stopped by the speed reducer 25 and the crank disk 26.

  The surface of the test piece after the abrasion test is visually evaluated for sensory evaluation and evaluated according to the following criteria. In the following, 下 記 and ○ are acceptable for practicability.

  From Table 1 above, it is shown that the split leathers (1) to (12) of the present invention have wrinkles close to those of genuine leather. From this, the split leather having the gaps defined in the present invention can be provided with wrinkles of wrinkles that are typical of genuine leather by a simple method. In contrast, comparative split leather (1) has small wrinkles and is difficult to see; comparative split leather (2) has too large wrinkles and does not look good; and comparative split leather (3) has shallow wrinkles and looks good bad. From this, it can be seen that the split leather that does not have the gap defined in the present invention cannot give wrinkles of wrinkles that are characteristic of genuine leather.

  Moreover, it turns out that abrasion resistance can be improved from the said Table 1 by including a silicone resin in a coating-film layer (topcoat layer). Here, split leather (9) having a silicone resin weight average molecular weight of less than 300 becomes slippery, and conversely, split leather (10) having a silicone resin weight average molecular weight exceeding 10,000 becomes sticky. A little inferior. From this, it is considered that the feel of split leather can be improved by setting the weight average molecular weight of the silicone resin to 300 to 10,000.

  Furthermore, from Table 1 above, the split leather (11) in which the addition amount of the silicone resin to the coating layer (topcoat layer) is less than 1% by weight increases the frictional resistance of the coating and is likely to wear. Durability decreases. On the contrary, the split leather (12) in which the addition amount of the silicone resin exceeds 15% by weight has a high gloss, and the appearance and appearance deteriorate. From this, it is considered that the wear resistance, appearance / look and feel of split leather can be improved by setting the addition amount of the silicone resin to the coating layer to 1 to 15% by weight.

1 ... Split leather,
2 ... fiber layer,
3 ... coating layer,
11 ... Drum,
12 ... Supply port,
13 ... staking equipment,
14 ... floor leather,
15 ... convex member,
16 ... vibration means,
17 ... recess,
20 ... Traverse wear tester,
21 ... Split leather (test piece),
22 ... Sample stage,
23 ... friction,
24 ... motor,
25 ... reducer,
26 ... Crank disc.

Claims (5)

  A fiber layer having a width (W) of 1 to 10 μm, a length (L) of 10 μm or more, and a ratio of length to width (L / W) of 2 or more, and formed on the fiber layer. A split leather having a coating layer;   The split leather according to claim 1, wherein the fiber layer is derived from floor leather.   The split leather according to claim 1 or 2, wherein the coating layer includes a silicone resin having a weight average molecular weight of 300 to 10,000.   The split leather according to claim 3, wherein the silicone resin is contained in the coating layer in an amount of 1 to 15% by weight in terms of solid content.   Perform blanking for 3 hours or more and staking for 1 minute or more. The fiber layer has a width (W) of 1 to 10 μm, a length (L) of 10 μm or more, and a ratio of length to width (L / W). The manufacturing method of the split leather of any one of Claims 1-4 which has forming a 2 or more clearance gap.