Skin material

Abstract

To provide a skin material that contains biomass powder, excellent in designability and peeling resistance.SOLUTION: The skin material has a base fabric, a medium layer, an adhesion layer and a skin layer in this sequence. The medium layer is made of skin material that contains a biomass powder.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a skin material. [Background technology]

[0002] 2. Description of the Related Art Synthetic leather and other skin materials are highly durable and therefore are widely used in automobile interior parts such as instrument panels, door trims, seats, and ceilings, railway car and aircraft interior parts such as trims, seats, and ceilings, furniture, shoes, footwear, bags, interior and exterior components for building decoration, clothing coverings and linings, wall coverings, and the like.

[0003] On the other hand, the raw materials for the skin materials of synthetic leather and other products are plastic materials such as polyvinyl chloride resin and polyurethane resin, and it is necessary to reduce the amount of these materials used in order to achieve a decarbonized society and carbon neutrality. Therefore, in recent years, active efforts have been made to use biomass-derived plastics and mixtures of biomass with plastic materials.

[0004] For example, Patent Document 1 describes a fabric mainly made of polylactic acid fiber, with a fineness of 1 to 30 dtex and a basis weight of 50 to 1000 g / m 2 The skin material is a natural fiber mixed with polylactic acid resin as a binder, and the apparent density is 0.4 to 1.5 g / cm 3 and a base material with a basis weight of 150 to 1500 g / m2, mainly made of polylactic acid fiber. 2 The document describes an automobile interior component having at least a three-layer structure in which a sound-absorbing material having a thickness within the range of 100 mm or less is laminated.

[0005] For example, Patent Document 2 describes a method for manufacturing interior parts, which includes a mixing step of mixing wood flour and a basic substance, a kneading step of feeding the mixture of wood flour and the basic substance with resin into a kneader and kneading the resin in a thermally molten state, and a molding step of molding an interior part using the plant fiber reinforced resin obtained in the kneading step. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2006-264436 A [Patent Document 2] JP 2018-95708 A Summary of the Invention [Problem to be solved by the invention]

[0007] The automobile components described in Patent Document 1 use polylactic acid fibers made from starch extracted from plants, but no consideration has been given to using powdered biomass (hereinafter referred to as "biomass powder") as a skin material.

[0008] Furthermore, in the manufacturing method for interior parts described in Patent Document 2, wood powder is used as the biomass powder, but no consideration is given to the durability and design of interior parts manufactured using the biomass powder.

[0009] The present disclosure has been made in consideration of the above-mentioned problems, and an object of one embodiment of the present disclosure is to provide a skin material that contains biomass powder and has excellent design properties and peel resistance. [Means for solving the problem]

[0010] The present disclosure includes the following aspects. <1> The skin material has a base fabric, an intermediate layer, an adhesive layer, and a skin layer in this order, and the intermediate layer contains biomass powder. <2> The content of biomass powder is 8% by mass or more based on the total amount of the skin material. <1> The skin material is as described above. <3> The average particle size of the biomass powder is 60 μm or less. <1> or <2> The skin material is as described above. <4> The biomass powder includes at least one selected from the group consisting of apple powder, bamboo powder, and cypress powder. <1> ~ <3> 10. The skin material according to claim 9, wherein the first and second insulating layers are made of a fluororesin. <5> The base fabric contains at least one of synthetic fibers and regenerated fibers. <1> ~ <4> 10. The skin material according to claim 9, wherein the first and second insulating layers are made of a fluororesin. <6> The biomass ratio of the skin material is 20% by mass or more. <1> ~ <5> 10. The skin material according to claim 9, wherein the first and second insulating layers are made of a fluororesin. <7> An intermediate layer is further provided between the skin layer and the adhesive layer. <1> ~ <6> 10. The skin material according to claim 9, wherein the first and second insulating layers are made of a fluororesin. Effect of the Invention

[0011] According to the present disclosure, there is provided a skin material using biomass powder, which has excellent design properties and peel resistance. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of a skin material according to the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing another embodiment of a skin material according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The covering material of the present disclosure will be described in detail below. The present disclosure is not limited to the following embodiments, which may be modified as appropriate within the scope of the present disclosure.

[0014] In the present disclosure, a numerical range indicated using "~" indicates a range that includes the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described in the present disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in the present disclosure. In addition, in the numerical ranges described in the present disclosure, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.

[0015] In the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the corresponding substances present in the composition, unless otherwise specified.

[0016] In the present disclosure, the term "step" encompasses not only independent steps, but also steps that cannot be clearly distinguished from other steps as long as a desired purpose is achieved.

[0017] In the present disclosure, the term "solid content" refers to, for example, the amount of components excluding the solvent among all components contained in the composition.

[0018] In the present disclosure, "mass %" and "weight %" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0019] In the present disclosure, the "biomass ratio" is a value (%) calculated based on the following formula. Biomass ratio = (total mass of biomass components in skin material / mass of skin material) x 100

[0020] <Skin material> The skin material of the present disclosure has a base fabric, an intermediate layer, an adhesive layer, and a skin layer in this order, and the intermediate layer contains biomass powder. The skin material of the present disclosure may have layers other than the intermediate layer, the adhesive layer, and the skin layer.

[0021] In recent years, from the perspective of environmental conservation and effective utilization of resources, biomass, such as food and thinned wood that would previously have been discarded, has been used to produce energy, biodegradable plastics, industrial raw materials, and the like. In the present disclosure, from the viewpoint of environmental consideration and effective utilization of resources, powdered apples, bamboo, and cypress, which have traditionally been discarded, are used as biomass. In the skin material of the present disclosure, by incorporating biomass powder particularly in the intermediate coating layer in the skin material configuration, it is possible to increase the biomass ratio and to achieve excellent design and peel resistance. Furthermore, by incorporating biomass powder in layers other than the intermediate layer, the biomass ratio can be increased. However, from the viewpoint of design, in the skin material of the present disclosure, it is preferable that the skin layer does not substantially contain biomass powder. Moreover, from the viewpoint of peel resistance, in the skin material of the present disclosure, it is preferable that the adhesive layer does not substantially contain biomass powder. Furthermore, when layers other than the intermediate layer, adhesive layer, and skin layer are provided, it is preferable that the other layers do not substantially contain biomass powder from the viewpoints of design and peel resistance. That is, in the skin material of the present disclosure, it is particularly preferable from the viewpoints of design and peel resistance that the intermediate layer selectively contains biomass powder.

[0022] "Substantially free of biomass powder" means that the content of biomass powder is 1 mass% or less based on the total amount of the layer, or that no biomass powder is included.

[0023] In addition, in the skin material of the present disclosure, from the viewpoints of the biomass ratio and physical properties, it is preferable to use a base fabric containing at least one of synthetic fibers and recycled fibers.

[0024] The biomass ratio of the skin material is preferably 20% by mass or more, and more preferably 25% by mass or more. In particular, when the base fabric is made of synthetic fibers and regenerated fibers, the biomass ratio of the skin material is preferably 20% by mass to 50% by mass. In addition, when the base fabric is made of natural fibers, the biomass ratio of the skin material is preferably 50% by mass to 70% by mass.

[0025] A preferred embodiment of the skin material of the present disclosure is as follows. The biomass powder has an average particle size of 60 μm or less, the content of the biomass powder is 50 mass% or less relative to the solid content concentration of the intermediate layer, the biomass powder includes at least one selected from the group consisting of apple powder, bamboo powder, and cypress powder, the base fabric includes at least one of recycled fibers and natural fibers, and the biomass ratio of the skin material is 20 mass% or more.

[0026] More preferred embodiments of the skin material of the present disclosure are as follows. The biomass powder has an average particle size of 30 μm or less, the content of the biomass powder is 45 mass% or less relative to the solid content concentration of the intermediate layer, the biomass powder includes at least one type selected from the group consisting of apple powder, bamboo powder, and cypress powder, the base fabric includes recycled fibers, and the biomass ratio of the skin material is 25 mass% or more.

[0027] [Layer structure of skin material] The layer structure of the skin material of the present disclosure will now be described. It should be noted that the dimensions in each drawing do not necessarily represent the actual dimensions.

[0028] FIG. 1 is a schematic cross-sectional view showing one embodiment of the layer structure of the skin material of the present disclosure. The skin material 1 shown in FIG. 1 comprises a base fabric 2, an intermediate layer 3, an adhesive layer 4, and a skin layer 5, in this order.

[0029] FIG. 2 is a schematic cross-sectional view showing another embodiment of the covering material of the present disclosure. The skin material 10 shown in FIG. 2 includes a base fabric 12, an intermediate layer 13, an adhesive layer 14, an intermediate layer 16, and a skin layer 15, in this order.

[0030] Each component of the skin material of the present disclosure will be described in detail below.

[0031] <Base fabric> The covering material of the present disclosure includes a base fabric. The base fabric used in the present disclosure is not particularly limited, but it is preferable that it has the necessary strength and flexibility.

[0032] Examples of fibers constituting the base fabric include synthetic fibers such as polyester, polyamide, polyacrylonitrile, acrylic, and polyurethane; natural fibers such as cotton and hemp; and regenerated fibers such as rayon.

[0033] The fibers constituting the base fabric may be used alone or in combination of two or more kinds. For example, the use of polyurethane as the fiber constituting the base fabric improves the elasticity of the base fabric, and the use of Kevlar fiber, which is a high-strength polyamide fiber, improves the strength of the base fabric.

[0034] Of these, from the viewpoint of the biomass ratio and physical properties of the skin material, the base fabric preferably contains at least one of synthetic fibers and regenerated fibers, and more preferably contains both synthetic fibers and regenerated fibers.

[0035] The base fabric of the present disclosure may be any of woven fabric, knitted fabric, and nonwoven fabric. Among these, woven fabric is preferred from the viewpoint of easily imparting a certain degree of stretchability in the width direction of the skin material.

[0036] Examples of woven fabrics include plain weave, twill weave, and satin weave. Among these, twill weave is more preferred from the viewpoint of physical properties.

[0037] The basis weight of the base fabric is set to 30 g / m2 from the viewpoint of better moldability, appearance after molding, and texture. 2 ~700g / m 2 is preferred, and 100 g / m 2 ~500g / m 2 is more preferred. The basis weight of the base fabric can be adjusted, for example, in the case of a woven fabric, by changing the structure of the woven fabric, the thickness of the fibers used in weaving, the structure, the density of the fibers, and the like.

[0038] The thickness of the base fabric used for the skin material is not particularly limited, but from the viewpoint of the strength and peel resistance of the skin material, it is preferably 300 μm to 1200 μm, and more preferably 500 μm to 1000 μm.

[0039] <Middle layer> The surface material of the present disclosure includes a middle layer. By including the middle layer of the present disclosure, it is possible to impart cushioning and a sense of volume to the surface material. Only one middle layer may be provided, or two or more layers may be provided.

[0040] The intermediate layer of the present disclosure preferably contains at least a resin and a biomass powder.

[0041] [resin] The resin contained in the intermediate layer of the present disclosure is not particularly limited, and examples thereof include polyethylene resin, polystyrene resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyolefin resin, polyester resin, polycarbonate resin, polymethylpentene resin, polysulfone resin, polyether ketone resin, polyether sulfone resin, polyether imide resin, polyimide resin, fluorine resin, nylon resin, and acrylic resin, etc. These resins may be used alone or in combination of two or more. Among these, it is preferable to contain a polyurethane resin from the viewpoint of peel resistance.

[0042] Examples of polyurethane resins include polycarbonate-based polyurethane resins, polyether-based polyurethane resins, polyester-based polyurethane resins, and modified products thereof. When the skin material is required to have long-term peel resistance, it preferably contains a polycarbonate-based polyurethane resin.

[0043] [Biomass powder] The biomass powder contained in the intermediate layer of the present disclosure refers to a powder obtained by pulverizing organic matter derived from living organisms. The biomass powder is not particularly limited, and examples thereof include powders of wood materials, fruits, vegetables, grasses, tea, seaweed, fungi, etc.

[0044] Examples of wood materials include cypress, zelkova, cedar, pine, and camphor. Fruits include citrus fruits, apples, pears, persimmons, loquats, peaches, grapes, kiwi fruit, bananas, and plums. Vegetables include leafy vegetables such as Chinese cabbage, cabbage, spinach, lettuce, green onions, komatsuna, bok choy, mitsuba, mizuna, and Chinese chives; root vegetables such as daikon, carrots, turnips, burdock, and lotus root; stem vegetables such as onions, asparagus, and udo; flower vegetables such as cauliflower, broccoli, and myoga; sprouted vegetables such as bean sprouts, radish sprouts, and tomyo; and fruit vegetables such as eggplant, cucumber, tomato, bell pepper, paprika, pumpkin, strawberry, melon, and watermelon. Examples of the grass family include wheat, durum wheat, rye, triticale, barley, oats, oats, corn, rice, barnyard millet, foxtail millet, millet, bamboo, and kumazasa. Examples of tea include raw tea leaves, tea fruits, tea bushes, unfermented tea leaves, semi-fermented tea leaves, and fermented tea leaves. Examples of seaweed include wakame, kombu, mozuku, tsurumo, sujime, einkorn, kurome, arame, and nori. Examples of fungi include mushrooms.

[0045] Among these, wood materials, fruits, and grasses are preferred from the viewpoint of being rich in fiber. Among them, cypress, bamboo, and apple powder are preferred from the viewpoint of availability. Cypress, bamboo, and apple powder include materials that have been dried and crushed. For cypress, for example, roots, trunks, branches, or tree canopy can be used. For bamboo, for example, roots, rhizomes, bamboo culms, branches, or bamboo skin can be used. For apple, for example, flesh, skin, or bark can be used, and apple pomace can also be used.

[0046] The pulverization method for obtaining biomass powder from a biomass raw material is not particularly limited, and a conventional pulverization device can be used. Examples of the pulverization device include a screen mill, a hammer mill, a ball mill, a bead mill, a jet mill, a cutter mill, a vibration mill, a roller mill, a line mill, a stamp mill, a disk mill, a pin mill, a grinding mill, a rotor mill, a cyclone mill, a rod mill, a power mill, a pot mill, a jaw crusher, a gyratory crusher, an impact crusher, a roll crusher, and an edge runner.

[0047] The average particle size of the biomass powder is preferably 60 μm or less, more preferably 30 μm or less, and particularly preferably 20 μm or less, from the viewpoint of dispersibility with other components constituting the intermediate layer and processability of the intermediate layer. The lower limit of the average particle size is not particularly limited, and is, for example, 5 μm.

[0048] The average particle size of the biomass powder is a number average particle size and is measured by the following method. The skin material is cut in the thickness direction. The cut surface is observed using a scanning electron microscope (SEM). Thirty pieces of biomass powder are randomly selected and their diameters are measured. The average of the measured diameters is taken as the average particle size. If the biomass powder is not circular, the maximum diameter is taken as the diameter.

[0049] The biomass powder may be used alone or in combination of two or more kinds. From the standpoint of dispersibility with other components constituting the intermediate layer and processability of the intermediate layer, the content of the biomass powder is preferably 50 mass% or less, and more preferably 45 mass% or less, relative to the solid concentration of the intermediate layer. The content of the biomass powder is 1% by mass to 30% by mass based on the composition for forming the intermediate layer. It is preferable that the content of the water-insoluble organic solvent is 1% by mass to 20% by mass, and more preferable that the content of the water-insoluble organic solvent is 1% by mass to 20% by mass.

[0050] The content of the biomass powder is preferably 90 parts by mass to 130 parts by mass, and more preferably 95 parts by mass to 120 parts by mass, relative to 100 parts by mass of the resin.

[0051] [Other ingredients] The intermediate layer of the present disclosure may contain other components in addition to the above-mentioned resin and biomass powder. Examples of the other components include colorants, processing aids, plasticizers, and fillers.

[0052] The intermediate layer of the present disclosure preferably contains a colorant. By containing a colorant, the color can be matched with the skin layer described later. This prevents the appearance from being impaired even when the skin material of the present disclosure is used in a product whose cross section is visible. The colorant may be used alone or in combination of two or more types.

[0053] The colorant of the present disclosure is not particularly limited, and may be a dye or a pigment. Examples of colorants include inorganic pigments such as titanium white (titanium dioxide), zinc white, ultramarine, cobalt blue, red iron oxide, vermilion, yellow lead, titanium yellow, and carbon black; organic pigments or dyes such as quinacridone, permanent red 4R, isoindolinone, Hansa Yellow A, phthalocyanine blue, indanthrene blue RS, and aniline black; metal pigments selected from the group consisting of foil powder of metals such as aluminum and brass; and pearlescent (pearl) pigments selected from the group consisting of foil powder of titanium dioxide-coated mica and basic lead carbonate. Among these, from the viewpoint of peel resistance, pigments are preferred as colorants.

[0054] The type and content of the colorant may be appropriately selected depending on the desired hue of the covering material.

[0055] When the intermediate layer contains a colorant, the content of the colorant is preferably 0.1% by mass to 10% by mass, and more preferably 0.1% by mass to 5% by mass, based on the composition for forming the intermediate layer, from the viewpoint of hiding power.

[0056] The content of the colorant is preferably 1 to 15 parts by mass, and more preferably 5 to 10 parts by mass, relative to 100 parts by mass of the resin.

[0057] In addition, the intermediate layer of the present disclosure is preferably formed using a cell regulator. By using the cell regulator, holes (voids) can be formed in the layer, and the ratio of the formed holes in the layer (porosity) can be adjusted. The cells refer to the holes (voids) formed in the intermediate layer. The cell regulator will be described in detail below.

[0058] From the viewpoint of maintaining the strength of the skin material, the porosity of the intermediate layer is preferably 60% or less, more preferably 50% or less, and the lower limit is preferably 15% or more, more preferably 25% or more.

[0059] The porosity is measured by the following method. The intermediate layer is observed with a scanning electron microscope (SEM), and the void areas in the intermediate layer are determined from the SEM photograph of the cross section of the intermediate layer observed by image processing, and the area occupied by the void areas is subtracted from the area of ​​the intermediate layer to determine the area.

[0060] From the viewpoint of peel resistance, the thickness of the intermediate layer is preferably 50 μm to 1000 μm, and more preferably 100 μm to 500 μm.

[0061] The intermediate layer can be formed by preparing a composition for forming an intermediate layer containing a resin, a biomass powder, a solvent, and other components as necessary, and applying (for example, coating) the composition onto a base fabric. The details of the resin, the biomass powder, and the other components are as described above.

[0062] The composition for forming the intermediate layer preferably contains a cell regulator as another component. By including the cell regulator, holes (voids) can be formed in the layer, and the ratio of the formed holes in the layer (porosity) can be adjusted. The cell refers to the holes (voids) formed in the intermediate layer. The cell regulator may be used alone or in combination of two or more kinds.

[0063] The cell regulator is not particularly limited, and examples thereof include polyether resins, silicone resins, anionic surfactants, etc. As the cell regulator, it is preferable to use a mixture of polyether resins, silicone resins, and anionic surfactants.

[0064] When the composition for forming the intermediate layer contains a cell regulator, the content of the cell regulator is preferably 0.1% by mass to 10% by mass, and more preferably 0.1% by mass to 5% by mass, relative to the composition for forming the intermediate layer, from the viewpoints of the strength and porosity of the intermediate layer.

[0065] The content of the cell regulator is preferably 0.1 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the resin.

[0066] <Adhesive layer> The skin material of the present disclosure includes an adhesive layer. The skin material has an adhesive layer, which allows adjacent layers to be bonded together. Only one adhesive layer may be provided, or two or more adhesive layers may be provided.

[0067] The adhesive layer preferably contains a resin as an adhesive component. Examples of the resin include polyethylene resin, polystyrene resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyolefin resin, polyester resin, polyolefin resin, polycarbonate resin, polymethylpentene resin, polysulfone resin, polyether ketone resin, polyether sulfone resin, polyether imide resin, polyimide resin, fluorine resin, nylon resin, and acrylic resin. These resins may be used alone or in combination of two or more. Among these, from the viewpoint of adhesiveness, it is preferable to include at least one resin selected from the group consisting of polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, and polystyrene resin.

[0068] Examples of polyurethane resins include polycarbonate-based polyurethane resins, polyether-based polyurethane resins, and polyester-based polyurethane resins, as well as modified products thereof. Among these, it is more preferable to include a polycarbonate-based polyurethane resin from the viewpoint of hydrolysis resistance.

[0069] From the viewpoint of adhesiveness, the polyurethane resin is preferably crosslinked by a crosslinking agent. Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, a carbodiimide crosslinking agent, and an oxazoline crosslinking agent. Among these, the crosslinking agent is preferably an isocyanate crosslinking agent.

[0070] Examples of polyvinyl chloride resins include homopolymers of vinyl chloride, and copolymers of vinyl chloride with vinyl acetate, ethylene, propylene, alkyl vinyl esters, alkyl vinyl ethers, and the like.

[0071] Examples of polyvinylidene chloride resins include homopolymers of polyvinylidene chloride, and copolymers of vinyl chloride with vinyl chloride, acrylonitrile, methyl acrylate, ethyl acrylate, and the like.

[0072] Examples of polystyrene resins include homopolymers of styrene, and copolymers of vinyl chloride with acrylonitrile, methyl methacrylate, and the like.

[0073] The resin contained in the adhesive layer may be the same as or different from the resin contained in the intermediate layer and the skin layer described below.

[0074] [Other ingredients] The adhesive layer of the present disclosure may contain components other than the above-mentioned resins. Examples of the other components include an accelerator.

[0075] The accelerator is preferably contained from the viewpoint of promoting crosslinking. Examples of the accelerator include amine-based and organometallic accelerators.

[0076] From the viewpoints of adhesion to adjacent layers and the texture of the skin material, the thickness of the adhesive layer is preferably in the range of 20 μm to 300 μm, more preferably 20 μm to 200 μm, and particularly preferably 20 μm to 100 μm.

[0077] The adhesive layer can be formed by preparing a composition for forming an adhesive layer containing a resin, a solvent, and other components as necessary, and applying (e.g., coating) the composition onto, for example, the surface layer or intermediate layer described below.

[0078] <Epidermal layer> The skin material of the present disclosure has a skin layer. The inclusion of the skin layer enhances design.

[0079] From the viewpoint of peel resistance, the surface layer of the present disclosure preferably contains a resin. Examples of the resin include polyurethane resin, polyvinyl chloride resin, acrylic resin, polyester resin, silicone resin, polyolefin resin, polystyrene elastomer resin, etc. Among these, from the viewpoint of easily obtaining various properties required for the skin material, it is preferable that the skin layer contains at least one of polyurethane resin and polyvinyl chloride resin.

[0080] Examples of polyurethane resins include polycarbonate-based polyurethane resins, polyether-based polyurethane resins, and polyester-based polyurethane resins, as well as modified products thereof. Among these, from the viewpoint of long-term peel resistance, it is more preferable that the surface layer contains a polycarbonate-based polyurethane resin.

[0081] In addition, the 100% modulus of polyurethane resin measured at 20°C is 2MPa (2×10 6 N / m 2 When the 100% modulus value of the polyurethane resin is within the above range, the skin material has excellent elasticity.

[0082] The 100% modulus value is a value indicating the hardness measured at 20°C in accordance with JIS K 6251 (2017).

[0083] In addition, the hardness (100% modulus) of the polyurethane resin can be adjusted, for example, by changing the type of raw material used when synthesizing the polyurethane resin. In order to soften the polyurethane resin, the content of the polyol that becomes the soft segment can be increased, or the molecular weight of the polyol can be increased. On the other hand, in order to harden a polyurethane resin, a method of forming a crosslinked structure can be mentioned, in which the number of urethane bonds or urea bonds that become hard segments is increased, or a crosslinking agent such as hexamethylene diisocyanate (HDI), hydrogenated xylylene diisocyanate (hydrogenated XDI), isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (hydrogenated MDI) or the like is added.

[0084] Examples of polyvinyl chloride resins include vinyl chloride homopolymers having an average degree of polymerization of 650 to 1800, and ethylene / vinyl chloride copolymers.

[0085] The skin layer may contain components other than the resin. Examples of the other components include colorants, processing aids, plasticizers, and fillers. When the surface layer contains other components, the content of the other components is preferably adjusted within a range that does not reduce peel resistance.

[0086] The skin layer preferably contains a colorant as another component. When the skin layer contains a colorant, the colorant may be used alone or in combination of two or more kinds.

[0087] The type and content of the colorant may be appropriately selected depending on the desired hue of the covering material. When the surface layer contains a colorant, the content of the colorant is preferably 0.1% by mass to 20% by mass, and more preferably 1% by mass to 10% by mass, based on the composition for forming the surface layer, from the viewpoint of design.

[0088] The content of the colorant is preferably 0.1 to 100 parts by mass, and more preferably 0.1 to 70 parts by mass, relative to 100 parts by mass of the resin.

[0089] From the viewpoint of peel resistance, the thickness of the skin layer is preferably from 10 μm to 400 μm, and more preferably from 15 μm to 250 μm.

[0090] When the surface layer contains polyurethane, the thickness of the surface layer is preferably from 10 μm to 100 μm, and more preferably from 15 μm to 40 μm, from the viewpoint of peel resistance.

[0091] When the surface layer contains polyvinyl chloride, the thickness of the surface layer is preferably 50 μm to 400 μm, and more preferably 150 μm to 250 μm, from the viewpoint of peel resistance.

[0092] The surface layer can be formed by preparing a composition for forming the surface layer containing a resin, a solvent, and, if necessary, other components, and applying (eg, coating) the composition to a substrate such as release paper.

[0093] The skin material of the present disclosure may include other layers in addition to the base fabric, the intermediate layer, the adhesive layer, and the skin layer. Examples of the other layers include an intermediate layer and a surface treatment layer.

[0094] <Middle Class> The skin material of the present disclosure may have an intermediate layer between the adhesive layer and the skin layer. By having the intermediate layer, the skin material can be given design and a sense of volume. Only one intermediate layer may be provided, or two or more intermediate layers may be provided.

[0095] From the viewpoint of peel resistance, the intermediate layer preferably contains a resin. Examples of the resin include polyurethane resin, polyvinyl chloride resin, acrylic resin, polyester resin, silicone resin, polyolefin resin, polystyrene elastomer resin, etc. Among these, from the viewpoint of easily obtaining various properties required for the intermediate layer, it is preferable that the intermediate layer contains at least one of a polyurethane resin and a polyvinyl chloride resin.

[0096] Examples of polyurethane resins include polycarbonate-based polyurethane resins, polyether-based polyurethane resins, and polyester-based polyurethane resins, as well as modified products thereof. Examples of polyvinyl chloride resins include homopolymers of vinyl chloride and polymers of vinyl chloride with other polymers. Among these, from the viewpoint of long-term peel resistance, it is more preferable that the intermediate layer contains a polycarbonate-based polyurethane resin.

[0097] The intermediate layer may contain components other than the resin. Examples of the other components include colorants, processing aids, plasticizers, and fillers. When the intermediate layer contains other components, the content of the other components is preferably adjusted within a range that does not reduce peel resistance.

[0098] The intermediate layer preferably contains a colorant as another component. When the intermediate layer contains a colorant, the colorant may be used alone or in combination of two or more kinds.

[0099] The type and content of the colorant may be appropriately selected depending on the desired hue of the covering material.

[0100] When the intermediate layer contains a colorant, the content of the colorant is preferably 5% by mass to 30% by mass, and more preferably 10% by mass to 20% by mass, based on the composition for forming the intermediate layer, from the viewpoint of hiding power.

[0101] The content of the colorant is preferably 10 to 80 parts by mass, and more preferably 40 to 70 parts by mass, relative to 100 parts by mass of the resin.

[0102] From the viewpoint of peel resistance, the thickness of the intermediate layer is preferably from 10 μm to 400 μm, and more preferably from 20 μm to 60 μm.

[0103] The intermediate layer can be formed, for example, by preparing a composition for forming an intermediate layer containing a resin, a solvent, and, if necessary, other components, and applying (eg, coating) the composition onto the surface layer.

[0104] <Surface treatment layer> The skin material of the present disclosure may have a surface treatment layer on the surface of the skin layer. By having the surface treatment layer, abrasion resistance is improved.

[0105] The surface treatment layer can be formed, for example, by applying a polyurethane resin surface treatment agent to the surface of the skin layer. Examples of polyurethane resins that can be used in the polyurethane resin surface treatment agent include polycarbonate-based polyurethane resins, polyether-based polyurethane resins, polyester-based polyurethane resins, and modified products thereof. When the skin material is required to have long-term peel resistance, it preferably contains a polycarbonate-based polyurethane resin. A crosslinking agent, a lubricant, and a colorant may be further added to the surface treatment agent containing the polyurethane resin.

[0106] <Method of manufacturing skin material> The method for producing the skin material of the present disclosure is not particularly limited, and any known method can be used. The method for producing the skin material of the present disclosure may include, for example, a step of forming an intermediate layer on a base fabric using a composition for forming an intermediate layer (step 1), a step of forming a skin layer on a temporary support such as release paper using a composition for forming a skin layer (step 2), a step of forming an adhesive layer on one side of the skin layer using a composition for forming an adhesive layer (step 3), a step of attaching the intermediate layer and the adhesive layer (step 4), and a step of peeling off and removing the temporary support (step 5).

[0107] An example of a method for producing a skin material according to the present disclosure will now be described in detail.

[0108] [Process 1] In step 1, an intermediate layer is formed on a base fabric using a composition for forming an intermediate layer. Methods for forming the intermediate layer include, for example, a method in which a composition for forming an intermediate layer containing biomass powder is applied to a base fabric and dried (dry processing method), or a method in which a composition for forming an intermediate layer containing biomass powder is applied to a base fabric and wet solidified (wet processing method).

[0109] The skin material of the present disclosure is preferably produced using a wet processing method. By using the wet processing method, the solvent contained in the composition for forming the intermediate layer is removed in a washing bath composed of water, and the intermediate layer becomes porous. This allows the skin material to be given cushioning properties and a sense of volume.

[0110] When the intermediate layer forming composition is applied onto a base fabric, the solid content concentration of the intermediate layer forming composition is preferably 10% by mass to 30% by mass.

[0111] Examples of methods for applying the composition for forming the intermediate layer include a knife coater method, a blade coater method, a roll coater method, a bar coater method, a curtain coater method, and a gravure coater method.

[0112] The amount of the composition for forming the intermediate layer to be applied is appropriately adjusted depending on the thickness of the intermediate layer. For example, the amount of the composition to be applied is 600 g / m 2 ~800g / m 2 It is.

[0113] After the intermediate layer forming composition is applied, it is dried through a wet coagulation tank and a cleaning tank. The drying method is not particularly limited. For example, a hot air dryer or a warm air dryer can be used as the drying device. The drying temperature and drying time may be, for example, 80°C to 130°C and 3 minutes to 5 minutes.

[0114] Methods for forming the intermediate layer composition into a sheet include, for example, a calendar method, a melt extrusion method, and a casting method.

[0115] [Process 2] In step 2, a skin layer is formed using a composition for forming a skin layer. Examples of methods for forming the surface layer include a method of applying the composition onto a release paper, which is a temporary support, and drying the composition, and a method of forming the composition into a sheet by applying a known film-forming method.

[0116] When the composition for forming a surface skin layer is applied onto a temporary support, the solid content concentration of the composition for forming a surface skin layer is preferably 10% by mass to 30% by mass.

[0117] The temporary support is not particularly limited as long as it is made of a material that can be peeled off in a later step. For example, release paper can be used as the temporary support.

[0118] Examples of methods for applying the composition for forming a skin layer include a knife coater method, a blade coater method, a roll coater method, a bar coater method, a curtain coater method, and a gravure coater method.

[0119] The amount of the composition for forming the skin layer to be applied is appropriately adjusted depending on the thickness of the skin layer. For example, 2 ~150g / m 2 It is.

[0120] The method of drying the composition for forming the surface layer after application is not particularly limited. For example, a hot air dryer or a warm air dryer can be used as a drying device. The drying temperature and drying time may be, for example, 90°C to 130°C and 2 minutes to 4 minutes.

[0121] In addition, epidermal layer formation for Methods for forming the composition into a sheet include, for example, a calendar method, a melt extrusion method, and a casting method.

[0122] [Process 3] In step 3, an adhesive layer is formed on one surface of the skin layer using a composition for forming an adhesive layer.

[0123] The adhesive layer may be formed, for example, by applying an adhesive layer-forming composition onto the intermediate layer and drying it.

[0124] The solid content concentration of the adhesive layer-forming composition is preferably 40% by mass to 60% by mass.

[0125] Examples of methods for applying the adhesive layer-forming composition include a knife coater method, a blade coater method, a roll coater method, a bar coater method, a curtain coater method, and a gravure coater method.

[0126] The amount of the composition for forming an adhesive layer to be applied is appropriately adjusted depending on the thickness of the adhesive layer. For example, 2 ~200g / m 2 It is.

[0127] The method of drying the adhesive layer-forming composition after application is not particularly limited. For example, a hot air dryer or a warm air dryer can be used as a drying device. The drying temperature and drying time are, for example, 90°C to 130°C and 2 minutes to 4 minutes.

[0128] [Step 4] In step 4, the intermediate layer and the adhesive layer are attached. For example, the base fabric provided with the intermediate layer and the temporary support provided with the adhesive layer and the skin layer are attached so that the intermediate layer and the adhesive layer are in contact with each other. This results in a laminate having a laminate structure of temporary support / skin layer / adhesive layer / intermediate layer / base fabric. The method for attaching the intermediate layer and the adhesive layer is not particularly limited, and for example, a laminator equipped with a roller can be used.

[0129] The lamination temperature is, for example, 80°C to 120°C. The conveying speed during lamination is, for example, 5 m / min to 10 m / min.

[0130] [Step 5] In step 5, the temporary support is peeled off and removed. To facilitate peeling, it is preferable to age the laminate before peeling.

[0131] The aging temperature is, for example, 40°C to 70°C. The maturation time is, for example, 12 to 72 hours.

[0132] Step 5 may be carried out after any of steps 1 to 4, but is preferably carried out after step 4.

[0133] The method for producing a skin material according to the present disclosure may include steps other than steps 1 to 5 described above. For example, when an intermediate layer is provided as an optional layer on the skin material, it is preferable to provide a step (step 6) of forming an intermediate layer on one side of the skin layer using a composition for forming an intermediate layer before carrying out the above step 3. In the above case, after the intermediate layer is formed, the above steps 3 to 5 are carried out to produce the skin material.

[0134] [Step 6] In step 6, an intermediate layer is formed on one surface of the skin layer using a composition for forming an intermediate layer. The intermediate layer may be formed, for example, by applying a composition for forming an intermediate layer onto the surface layer and drying it.

[0135] The solid content concentration of the intermediate layer forming composition is preferably 10% by mass to 40% by mass.

[0136] Examples of methods for applying the composition for forming an intermediate layer include a knife coater method, a blade coater method, a roll coater method, a bar coater method, a curtain coater method, and a gravure coater method.

[0137] The amount of the composition for forming the intermediate layer to be applied is appropriately adjusted depending on the thickness of the adhesive layer. For example, 2 ~200g / m 2 It is.

[0138] The method of drying the composition for forming an intermediate layer after coating is not particularly limited. For example, a hot air dryer or a warm air dryer can be used as a drying device. The drying temperature and drying time are, for example, 90°C to 130°C and 2 minutes to 4 minutes.

[0139] The skin material of the present disclosure can be produced by a simple method, has excellent design properties and peel resistance, and can be suitably used in various fields such as automobile interior and exterior materials, interior parts for railway cars and aircraft, furniture, shoes, footwear, bags, interior and exterior components for building decoration, and clothing coverings and linings. EXAMPLES

[0140] The present disclosure will be described in more detail below with reference to examples. However, the present disclosure is not limited to the following examples as long as it does not deviate from the gist of the disclosure. In addition, unless otherwise specified, "parts" are based on mass.

[0141] Example 1 [Preparing the base fabric] As the base fabric, a woven fabric containing polyester fibers and rayon fibers, having a thickness of 700 μm and a mass of 257 g, was used.

[0142] [Preparation of intermediate layer] To prepare the intermediate layer, the following components were mixed to prepare a composition for forming the intermediate layer having a solid content concentration of about 24% by mass.

[0143] -Composition of the composition for forming the intermediate layer- One-component polycarbonate polyurethane resin (solid content concentration 30% by weight) 100 parts by weight Solvent (dimethylformamide: DMF) 150 parts by weight Cell regulator (polyether resin) 0.65 parts by weight Cell regulator (silicone resin) 0.30 parts by weight Cell regulator (methoxypropanol) 0.05 parts by weight Cell regulator (anionic surfactant) 0.5 parts by weight Colorant (pigment) 4 parts by weight Biomass powder (apple powder with an average particle size of 20 μm) 30 parts by weight

[0144] After preparation, the composition for forming the intermediate layer was applied onto the base fabric in a wet coating amount of 700 g / m 2 After coating, wet coagulation was performed and the coating film was dried at 125°C for 4 minutes using a hot air dryer to obtain a porous (porosity: 40%) intermediate layer having a thickness of 250 μm. This produced a base fabric with an intermediate layer. The content of the biomass powder was 44.1% by mass relative to the solid content concentration of the intermediate layer.

[0145] [Creation of epidermal layer] To prepare the surface layer, the following components were mixed to prepare a composition for forming the surface layer having a solid content of about 19% by mass.

[0146] -Composition of the composition for forming the epidermis layer- One-component polycarbonate polyurethane resin (solid content concentration 30% by weight) 100 parts by weight Solvent (dimethylformamide: DMF) 30 parts by weight Solvent (isopropyl alcohol: IPA) 15 parts by weight Solvent (triol) 15 parts by weight

[0147] After preparation, the composition for forming the surface skin layer was wet coated on release paper at a rate of 100 g / m 2 After the coating film was formed, the coating film was dried at 100° C. for 2 minutes using a hot air dryer to obtain a surface layer having a thickness of 18 μm.

[0148] [Creation of intermediate layer] To prepare the intermediate layer, the following components were mixed to obtain a composition for forming an intermediate layer having a solid content concentration of about 27% by mass.

[0149] -Composition of intermediate layer forming composition- ·One-component polycarbonate polyurethane resin (solid concentration 30% by mass) 100 parts by mass ·Solvent (dimethylformaldehyde: DMF) 30 parts by mass Solvent (methyl ethyl ketone: MEK) 30 parts by weight Colorant (pigment) 34 parts by weight

[0150] After preparation, the intermediate forming composition was applied to one side of the skin layer in a wet coating amount of 160 g / m 2 After the coating film was formed, the coating film was dried at 100° C. for 3 minutes using a hot air dryer to obtain an intermediate layer having a thickness of 28 μm.

[0151] [Creating adhesive layer] To prepare the adhesive layer, the following components were mixed to obtain a composition for forming an adhesive layer having a solid content concentration of about 51% by mass.

[0152] -Composition of adhesive layer-forming composition- Two-component polycarbonate polyurethane resin (solid content 72% by weight) 100 parts by weight Solvent (dimethylformaldehyde: DMF) 27 parts by weight Solvent (methyl ethyl ketone: MEK) 18 parts by weight Isoasarate crosslinking agent 9 parts by weight Accelerator (amine catalyst) 1.8 parts by weight

[0153] After preparation, the adhesive layer-forming composition was applied onto the intermediate layer in a wet coating amount of 130 g / m 2 After forming the coating film, the coating film was dried at 100°C for 3 minutes using a hot air dryer to obtain an adhesive layer with a thickness of 30 μm. This produced a laminate of adhesive layer / intermediate layer / surface layer / release paper.

[0154] Laminate The above-mentioned base fabric with intermediate layer and the laminate were superimposed with the intermediate layer and the adhesive layer in contact with each other, and were laminated using a laminator. The lamination temperature was 80°C, and the conveying speed was 8m / min. After aging at 50°C for 48 hours, the release paper was peeled off to obtain the skin material of Example 1.

[0155] Example 2 A skin material was prepared in the same manner as in Example 1, except that the base fabric was changed to 196 g cotton.

[0156] Example 3 The basis weight and thickness of the base fabric used in Example 1 and the wet coating amount of the intermediate layer composition were changed. As the base fabric, a woven fabric containing polyester fiber and rayon fiber with a thickness of 650 μm and a mass of 188 g was used. The wet coating amount of the intermediate layer composition was 740 g / m. 2 A skin material was prepared in the same manner as in Example 1 except for the above.

[0157] Example 4 A skin material was produced in the same manner as in Example 1, except that the basis weight and thickness of the base fabric used in Example 1, and the type and content of the biomass powder used in the intermediate layer were changed. The base fabric used was a woven fabric containing polyester fiber and rayon fiber with a thickness of 650 μm and a mass of 188 g. The biomass powder used was bamboo powder with an average particle diameter of 25 μm. The content of the biomass powder was 34.4 mass% relative to the solid content concentration of the intermediate layer.

[0158] Example 5 A skin material was produced in the same manner as in Example 1, except that the basis weight and thickness of the base fabric used in Example 1, and the type and content of the biomass powder used in the intermediate layer were changed. The base fabric used was a woven fabric containing polyester fiber and rayon fiber with a thickness of 650 μm and a mass of 188 g. The biomass powder used was bamboo powder with an average particle diameter of 25 μm. The content of the biomass powder was 28.3 mass% relative to the solid content concentration of the intermediate layer.

[0159] Example 6 A skin material was produced in the same manner as in Example 1, except that the basis weight and thickness of the base fabric used in Example 1, and the type and content of the biomass powder used in the intermediate layer were changed. The base fabric used was a woven fabric containing polyester fiber and rayon fiber with a thickness of 650 μm and a mass of 188 g. The biomass powder used was cypress powder with an average particle size of 50 μm. The content of the biomass powder was 39.7 mass% relative to the solid content concentration of the intermediate layer.

[0160] Example 7 A skin material was produced in the same manner as in Example 1, except that the basis weight and thickness of the base fabric used in Example 1, and the type and content of the biomass powder used in the intermediate layer were changed. The base fabric used was a woven fabric containing polyester fiber and rayon fiber with a thickness of 650 μm and a mass of 188 g. The biomass powder used was cypress powder with an average particle size of 50 μm. The content of the biomass powder was 34.4 mass% relative to the solid content concentration of the intermediate layer.

[0161] Example 8 A skin material was produced in the same manner as in Example 1, except that the basis weight and thickness of the base fabric used in Example 1, and the type and content of the biomass powder used in the intermediate layer were changed. The base fabric used was a woven fabric containing polyester fiber and rayon fiber with a thickness of 650 μm and a mass of 188 g. The biomass powder used was cypress powder with an average particle size of 50 μm. The content of the biomass powder was 28.3 mass% relative to the solid content concentration of the intermediate layer.

[0162] Comparative Example 1 [Preparing the base fabric] As the base fabric, a woven fabric containing polyester fibers and rayon fibers, having a thickness of 650 μm and a mass of 188 g, was used.

[0163] [Preparation of intermediate layer] To prepare the intermediate layer, the following components were mixed to obtain a composition for forming the intermediate layer having a solid content concentration of about 12% by mass.

[0164] -Composition of the composition for forming the intermediate layer- ·One-component polycarbonate polyurethane resin (solid content concentration 30% by mass) 100 parts by mass ·Solvent (dimethylformamide: DMF) 150 parts by mass ·Cell regulator (polyether resin) 0.65 parts by mass Cell regulator (silicone resin) 0.30 parts by weight Cell regulator (methoxypropanol) 0.05 parts by weight Cell regulator (anionic surfactant) 0.5 parts by weight Colorant (pigment) 4 parts by weight

[0165] After preparation, the composition for forming the intermediate layer was applied onto the base fabric in a wet coating amount of 740 g / m 2 After coating, a porous intermediate layer having a thickness of 250 μm was obtained by wet fixing, thereby producing a base fabric with an intermediate layer.

[0166] [Creation of epidermal layer] To prepare the epidermis layer, the following components were mixed to prepare a composition for forming an epidermis layer having a solids concentration of about 27% by mass.

[0167] -Composition of the composition for forming the epidermis layer- One-component polycarbonate polyurethane resin (solid content concentration 30% by weight) 100 parts by weight Solvent (dimethylformamide: DMF) 30 parts by weight Solvent (isopropyl alcohol: IPA) 15 parts by weight Solvent (triol) 15 parts by weight Biomass powder (apple powder with an average particle size of 20 μm) 20 parts by weight

[0168] After preparation, the composition for forming the skin was applied wet to a release paper at a rate of 100 g / m 2 After forming the coating film, the coating film was dried at 100°C for 3 minutes using a hot air dryer to obtain a skin layer with a thickness of 20 μm. The content of the biomass powder was 40 mass% relative to the solid concentration of the skin layer.

[0169] [Creation of intermediate layer] To prepare the intermediate layer, the following components were mixed to obtain a composition for forming an intermediate layer having a solid content concentration of about 27% by mass.

[0170] -Composition of intermediate layer forming composition- ·One-component polycarbonate polyurethane resin (solid content concentration 30% by mass) 100 parts by mass ·Solvent (dimethylformaldehyde: DMF) 30 parts by mass Solvent (methyl ethyl ketone: MEK) 30 parts by weight Colorant (pigment) 34 parts by weight

[0171] After preparation, the intermediate forming composition was applied onto the surface layer in a wet coating amount of 160 g / m 2 After the coating film was formed, the coating film was dried at 100° C. for 3 minutes using a hot air dryer to obtain an intermediate layer having a thickness of 28 μm.

[0172] [Creating adhesive layer] To prepare the adhesive layer, the following components were mixed to obtain a composition for forming an adhesive layer having a solid content concentration of about 51% by mass.

[0173] -Composition of adhesive layer-forming composition- Two-component polycarbonate polyurethane resin (solid content 72%) 100 parts by weight Solvent (dimethylformaldehyde: DMF) 27 parts by weight Solvent (methyl ethyl ketone: MEK) 18 parts by weight Isoasarate crosslinking agent 9 parts by weight Accelerator (amine catalyst) 1.8 parts by weight

[0174] After preparation, the adhesive layer-forming composition was applied onto the intermediate layer in a wet coating amount of 130 g / m 2 After forming the coating film, the coating film was dried at 100°C for 3 minutes using a hot air dryer to obtain an adhesive layer with a thickness of 30 μm. This produced a laminate of adhesive layer / intermediate layer / surface layer / release paper.

[0175] Laminate The base fabric with the intermediate layer and the laminate were overlapped with the intermediate layer and the adhesive layer in contact with each other, and then bonded together using a laminator. The lamination temperature was 80°C, and the conveying speed was 8 m / min. After aging at 50°C for 48 hours, the release paper was peeled off to obtain a skin material of Comparative Example 1.

[0176] Comparative Example 2 A skin material was prepared in the same manner as in Comparative Example 1, except that the compositions of the skin layer-forming composition and the adhesive layer composition were changed as follows.

[0177] -Composition of the composition for forming the epidermis layer- ·One-component polycarbonate-based polyurethane resin (solid content concentration 30% by mass) 100 parts by mass ·Solvent (dimethyl formaldehyde: DMF) 30 parts by mass ·Solvent (methyl ethyl ketone: MEK) 15 parts by mass ·Solvent (triol) 15 parts by mass The solid content concentration of the above-mentioned composition for forming the surface layer is approximately 19% by mass.

[0178] -Composition of adhesive layer-forming composition- ·Two-component polycarbonate polyurethane resin (solid content concentration 72% by mass) 100 parts by mass ·Solvent (dimethylformaldehyde: DMF) 27 parts by mass ·Solvent (methyl ethyl ketone: MEK) 18 parts by mass ·Isocyanate-based crosslinking agent 9 parts by mass ·Accelerator (amine-based catalyst) 1.8 parts by mass Biomass powder (apple powder with an average particle size of 20 μm) 20 parts by mass The solid content concentration of the adhesive layer forming composition is about 51% by mass. The content of the biomass powder was 20.2 mass % relative to the solid content concentration of the adhesive layer.

[0179] The mass of each layer and the ratio of biomass powder in Examples 1 to 8 and Comparative Examples 1 and 2 are shown in Tables 1 and 2.

[0180] [Table 1]

[0181] [Table 2]

[0182] The design properties and peel resistance were evaluated using Examples 1 to 8 and Comparative Examples 1 and 2. The evaluation methods are as follows.

[0183] <Design> The surface of the skin layer of each skin material was evaluated visually and tactilely by 10 workers. The evaluation criteria are as follows. A: Ten workers determined that no traces of biomass powder were observed on the surface of the epidermis layer by visual or tactile inspection. B: One or more workers determined that traces of biomass powder were observed visually and tactilely on the surface of the epidermis layer.

[0184] <Durability (peeling resistance)> Each skin material was cut to prepare a test piece measuring 17 mm x 130 mm. Each test piece was left to stand for 24 hours under conditions of 23°C and 50% relative humidity. After standing, the peel strength between the adhesive layer and the base fabric of each test piece was measured using a tensile tester (model number: RTG-1225, manufactured by A&D Co., Ltd.). The peel test was performed at a test speed of 200 mm / min and a peel angle of 180 degrees. The evaluation criteria were as follows: A: Peel strength 0.7kg / cm or more B: Peel strength less than 0.7kg / cm

[0185] <Durability (hydrolysis resistance)> Each skin material was cut to prepare a 120mm x 120mm test piece. Each test piece was hung in a Lightspec thermostatic and hygroscopic chamber (model number: LH-114, manufactured by Espec Corporation) with an internal temperature of 70℃ and humidity of 95%, and taken out every week. Each test piece was left to stand at 23°C for 24 hours, and the peel strength between the adhesive layer and the base fabric of each test piece was measured using a tensile tester (model number: RTG-1225, manufactured by A&D Co., Ltd.) The above peel strength test was performed on each test piece for up to 10 weeks. The peel strength at each week was compared with the peel strength at the start of the test, and an evaluation was made at the point when the peel strength became less than 60% of the peel strength at the start of the test. In making the evaluation, it was assumed that "one week of standing at a temperature of 70°C and a humidity of 95%" was equivalent to "one year of standing at 23°C and a relative humidity of 50%." For example, if the peel strength of the test piece in the third week was less than 60% of the peel strength at the start of the test, it was given a rating of C. The evaluation criteria are as follows. A rating of B or above is considered to be at a practical level. A: Durability of over 10 years B: Durability of 3 years or more but less than 10 years C: Durability less than 3 years

[0186] The evaluation results are shown in Table 3.

[0187] [Table 3]

[0188] As shown in Table 3, Examples 1 to 8, which contained biomass powder in the intermediate layer, were shown to have excellent design properties and peel resistance. Furthermore, the intermediate layer can contain a high proportion of biomass powder without reducing the design and peel resistance, and the biomass ratio is accordingly high. The biomass ratio can be further increased by using cotton, a natural fiber, for the base fabric. On the other hand, in Comparative Example 1, in which the skin layer contained biomass powder, the design was deteriorated, and in Comparative Example 2, in which the adhesive layer contained biomass powder, the peel resistance was poor. This result indicates that it is preferable to include biomass powder in the intermediate layer. [Explanation of symbols]

[0189] 1, 10...Skin material 2, 12...Base fabric 3, 13...Middle layer 4, 14...Adhesive layer 5, 15...epidermal layer 16. Middle class

Claims

1. A skin material comprising a base fabric, an intermediate layer, an adhesive layer, and a skin layer in this order, the intermediate layer containing biomass powder.

2. The skin material according to claim 1 , wherein the content of the biomass powder is 8% by mass or more based on the total amount of the skin material.

3. 3. The skin material according to claim 1 or 2, wherein the biomass powder has an average particle size of 60 μm or less.

4. The skin material according to claim 1 or 2, wherein the biomass powder comprises at least one selected from the group consisting of apple powder, bamboo powder, and cypress powder.

5. 3. The skin material according to claim 1, wherein the base fabric contains at least one of synthetic fibers and regenerated fibers.

6. 3. The skin material according to claim 1, wherein the biomass ratio of the skin material is 20% by mass or more.

7. 3. The skin material according to claim 1, further comprising an intermediate layer between the skin layer and the adhesive layer.

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