Full-grain leather-like seat

Abstract

This full-grain leather-like sheet is provided with a fiber substrate and a resin layer laminated on one surface of the fiber substrate, the resin layer includes at least one skin layer, and the skin layer contains polyurethane, a nonionic compound with an HLB value of 10-16, and a water-soluble polymer, and has a surface free energy with a 25-40 mJ / m2 polar part and a 30-40 mJ / m2 dispersive part, analyzed with OWRK.

Description

[Technical Field]

[0001] This invention relates to a silver-plated leather-like sheet that possesses high wettability, high water resistance, and high secondary adhesion. [Background technology]

[0002] As a material for shoes, bags, clothing, etc., there are known grain-finish leather-like sheets, such as artificial leather and synthetic leather, that have a grain-finish resin layer. A typical grain-finish leather-like sheet comprises a fiber base material and a resin layer containing polyurethane laminated on the fiber base material.

[0003] In recent years, in the manufacture of grain-finish leather-like sheets, there has been a demand for manufacturing methods that reduce the amount of organic solvents used and utilize aqueous polyurethane liquids such as emulsions, which are dispersed in an aqueous medium and contain aqueous polyurethane that can be dispersed in an aqueous medium, in order to reduce the environmental impact. For example, Patent Document 1 below discloses a grain-finish artificial leather having a grain surface layer formed using an aqueous polyurethane resin dispersion on at least one side of a base layer consisting of a polymer elastic material applied using a three-dimensional entangled nonwoven fabric and an aqueous resin dispersion.

[0004] Furthermore, Patent Document 2 below discloses a method for manufacturing a porous structure used in the production of a leather-like sheet, characterized by applying a mixed solution containing (A) an aqueous thermoplastic binder solution and (B) a urethane prepolymer terminal isocyanate block, in addition to (C) an inorganic compound, (D) a water-soluble organic polymer, and (E) a high-cloud-point surfactant, to a substrate, and then forming a porous body by heating with moist heat using steam, or by heating using high-frequency heating or high-frequency dielectric heating in combination, and then drying.

[0005] By the way, when processing the silver-coated leather-like sheet into secondary products such as shoes, bags, and clothing, surface treatment properties and secondary adhesiveness are required for the silver-colored resin layer. The surface treatment property of the silver-coated leather-like sheet is, for example, a treatment for adjusting the surface properties by applying a treatment liquid containing a pigment, a matting agent, an antibacterial agent, etc. to the surface of the resin layer by gravure coating or the like. Further, the secondary adhesiveness of the silver-coated leather-like sheet is the adhesiveness when adhering other materials with an adhesive to the surface of the silver-colored resin layer.

[0006] When the polyurethane for forming the silver-colored resin layer is aqueous polyurethane formed using an aqueous polyurethane solution, in order to maintain the storage stability of the aqueous polyurethane solution, it often contains relatively highly hydrophobic aqueous polyurethane. When a silver-colored resin layer is formed using such an aqueous polyurethane solution containing relatively highly hydrophobic aqueous polyurethane, since the hydrophobicity of the surface of the resin layer also increases, there is a problem that the wettability with respect to a highly polar aqueous treatment liquid decreases.

[0007] In order to solve such problems, for example, Patent Document 3 below discloses a leather-like sheet in which an urethane resin composition for forming an epidermal layer containing aqueous polyurethane is applied and dried on a release sheet to form an epidermal layer, and the epidermal layer and a fiber base material are laminated via an adhesive. And Patent Document 3 discloses improving the secondary adhesiveness while maintaining the water resistance by adjusting the ratio of the hydrophilic component and the hydrophobic component to improve the polarity of the aqueous polyurethane.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0009] To manufacture a highly water-resistant, silver-plated leather-like sheet, a resin layer containing highly water-resistant polyurethane is often used. In the leather-like sheet disclosed in Patent Document 3, increasing the water resistance of the resin layer surface makes it difficult to sufficiently improve polarity. Therefore, if the water resistance of the leather-like sheet disclosed in Patent Document 3 is further increased, it is unlikely that the sufficiently high wettability to water-based liquids required when surface-treating with a highly polar treatment liquid can be obtained. Furthermore, if the ratio of hydrophilic components in the polyurethane is increased to further improve the wettability of the resin layer surface, it is likely that the water resistance will decrease. Thus, there was a trade-off relationship between the wettability of the resin layer surface and water resistance.

[0010] Furthermore, as mentioned above, high secondary adhesion is sometimes required for silver-plated leather-like sheets. Conventional resin layers containing water-based polyurethane had high wettability but low secondary adhesion.

[0011] Thus, a silver-plated leather-like sheet possessing high wettability to water-based liquids, high water resistance, and high secondary adhesion had not been obtained.

[0012] The present invention aims to provide a silver-plated leather-like sheet that combines high wettability to aqueous liquids, high water resistance, and high secondary adhesion. [Means for solving the problem]

[0013] One aspect of the present invention is a silver-plated leather-like sheet comprising a fibrous substrate and a resin layer laminated on one surface of the fibrous substrate, wherein the resin layer is at least a surface layer. The surface layer comprises polyurethane, a nonionic compound with an HLB value of 10 to 16, and a water-soluble polymer, and has a polar component of 25 to 40 mJ / m³ as analyzed by the Owens-Wendt-Rabel-Kaelble method (hereinafter also referred to as the OWRK method). 2 The dispersion component is 30-40 mJ / m³.2 It has a surface free energy of . With such a silver-plated leather-like sheet, a silver-plated leather-like sheet can be obtained that has a resin layer surface that combines high wettability, high water resistance, and high secondary adhesion. Such polyurethane is usually an aqueous polyurethane that can be dispersed in an aqueous medium.

[0014] Furthermore, polyurethane, as analyzed by the OWRK method, has a polar component of 5-20 mJ / m³. 2 The dispersion component is 30-40 mJ / m³. 2 Having a surface free energy such as is preferable because it makes it easier to obtain a silver-plated leather-like sheet that combines high wettability, high water resistance, and high secondary adhesion.

[0015] Furthermore, it is preferable that the nonionic compound includes at least one selected from the group consisting of silicone-based compounds and acetylene glycol-based compounds, as this allows for a significant improvement in surface free energy even with the addition of a small amount.

[0016] Furthermore, it is preferable for the epidermal layer to contain 0.8 to 5.0% by mass of nonionic compounds, as this makes it easier to maintain sufficient wettability without reducing water resistance or secondary adhesion.

[0017] Furthermore, it is preferable that the water-soluble polymer has a number-average molecular weight of 10,000 to 150,000, and moreover, that it contains 1.0 to 10% by mass of the water-soluble polymer, as this makes it easier to maintain high secondary adhesion without reducing water resistance.

[0018] Furthermore, it is preferable that the epidermal layer be a continuous film with no pores and a thickness of 10 to 100 μm, as this provides an elegant appearance without any depressions or indentations on the surface of the epidermal layer.

[0019] Furthermore, it is preferable that the resin layer includes at least an adhesive layer with a thickness of 30 to 120 μm containing polyurethane for bonding to the fiber substrate, as this allows the resin layer to be firmly bonded to the fiber substrate. [Effects of the Invention]

[0020] According to the present invention, a silver-plated leather-like sheet is obtained that possesses high wettability to aqueous liquids, high water resistance, and high secondary adhesion. [Brief explanation of the drawing]

[0021] [Figure 1] This is a schematic cross-sectional view illustrating the layer structure of a full-grain leather-like sheet 10, which is an example of an embodiment. [Modes for carrying out the invention]

[0022] The present invention will be described in detail below with reference to one embodiment of a full-grain leather-like sheet.

[0023] Referring to Figure 1, an example of an embodiment, the full-grain leather-like sheet 10 comprises a fiber base material 1 and a resin layer 2 laminated on one surface of the fiber base material 1. The resin layer 2 includes a surface layer 2a, an intermediate layer 2b, and an adhesive layer 2c.

[0024] The adhesive layer 2c is a polyurethane-based layer arranged to bond the resin layer 2 to the fiber substrate 1. The intermediate layer 2b, which is interposed between the surface layer 2a and the adhesive layer 2c, is a polyurethane-based layer selected according to purposes such as adjusting the surface texture.

[0025] The surface layer 2a is preferably placed on the outermost surface of the resin layer and is a polyurethane-based layer that imparts high wettability, high water resistance, and high secondary adhesion to the surface of the resin layer. Specifically, the surface layer 2a contains at least polyurethane, a nonionic compound with an HLB value of 10 to 16, and a water-soluble polymer, and has a polar component of 25 to 40 mJ / m, as analyzed by the OWRK method. 2 The dispersion component is 30-40 mJ / m³. 2 This is a layer mainly composed of polyurethane having a surface free energy.

[0026] The grain-finish leather-like sheet of this embodiment, as exemplified by grain-finish leather-like sheet 10, comprises a resin layer laminated on one surface of a fiber substrate, which includes at least a surface layer containing polyurethane, a nonionic compound with an HLB value of 10 to 16, and a water-soluble polymer. Such a resin layer gives the grain-finish leather-like sheet a grain-like appearance. The resin layer may also have other layers as needed, such as an adhesive layer arranged to bond the surface layer to the fiber substrate, or an intermediate layer for adjusting the surface texture.

[0027] The fibrous base material is a woven fabric, knitted fabric, nonwoven fabric, or a combination thereof, or a fibrous entanglement composite. Among these, nonwoven fabric is particularly preferred because it maintains a supple texture. The fibrous base material may also contain a polymeric elastic material impregnated into the voids of the fibrous entanglement composite.

[0028] The type of resin used to form the fibers is not particularly limited. Specifically, examples include aromatic polyesters such as polyethylene terephthalate (PET), isophthalic acid-modified polyethylene terephthalate, sulfoisophthalic acid-modified polyethylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate; fatty acid polyesters such as polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, and polyhydroxybutyrate-polyhydroxyvalate copolymer; nylons such as nylon 6, nylon 66, nylon 10, nylon 11, nylon 12, and nylon 6-12; polyolefins such as polypropylene, polyethylene, polybutene, polymethylpentene, and chlorinated polyolefins; modified polyvinyl alcohols such as modified polyvinyl alcohol containing 25 to 70 mol% ethylene units; and elastomers such as polyurethane elastomers, polyamide elastomers, and polyester elastomers. Among these, PET, isophthalic acid-modified polyethylene terephthalate, polylactic acid, nylon 6, nylon 12, nylon 6-12, nylon copolymers, and polypropylene are particularly preferred due to their excellent spinnability and the mechanical properties of the resulting artificial leather. These resins may be used individually or in combination of two or more.

[0029] Furthermore, while the fineness of the fibers forming the fibrous base material is not particularly limited, it is especially preferable that the fibers be extremely fine, for example, have an average fineness of 0.001 to 0.5 dtex, as this provides a supple texture.

[0030] Furthermore, the fibrous base material may contain a polymeric elastic material impregnated into the voids of the fibrous entanglement. Specific examples of polymeric elastic materials impregnated into the voids of the fibrous entanglement include, for example, polyurethane, acrylonitrile elastomer, olefin elastomer, polyester elastomer, polyamide elastomer, and acrylic elastomer. Among these, crosslinked aqueous polyurethane obtained by coagulating a polyurethane emulsion is particularly preferred because it can reduce the amount of organic solvent used.

[0031] The content of the polymeric elastic material in the fiber base material is not particularly limited, but is preferably 5 to 60% by mass, and more preferably 8 to 40% by mass. The thickness of the fiber base material is not particularly limited, but is preferably 0.2 to 3.0 mm.

[0032] The grain-finish leather-like sheet of this embodiment, as exemplified by grain-finish leather-like sheet 10, comprises a resin layer laminated on one surface of a fiber substrate, which includes at least a surface layer containing polyurethane, a nonionic compound with an HLB value of 10 to 16, and a water-soluble polymer. Such a resin layer gives the grain-finish leather-like sheet a grain-like appearance. The resin layer may also have other layers as needed, such as an adhesive layer arranged to bond the surface layer to the fiber substrate, or an intermediate layer for adjusting the surface texture.

[0033] In this embodiment, the polyurethane is preferably an aqueous polyurethane derived from a polyurethane aqueous dispersion, which is an emulsion or dispersion in which polyurethane or its prepolymer is dispersed in water or a water-based aqueous medium. Aqueous polyurethane is a polyurethane that is distinct from solvent-based polyurethane derived from a polyurethane solution dissolved in an organic solvent. Aqueous polyurethane is, for example, a polyurethane obtained by reacting a urethane raw material containing a high-molecular-weight polyol, an organic polyisocyanate, a chain extender, and a polyfunctional compound used as needed.

[0034] Specific examples of polymeric polyols include, for example, polyether polyols and copolymers such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and poly(methyltetramethylene glycol); polyester polyols and copolymers such as polybutylene adipate diol, polybutylene sebacate diol, polyhexamethylene adipate diol, poly(3-methyl-1,5-pentylene adipate) diol, poly(3-methyl-1,5-pentylene sebacate) diol, and polycaprolactone diol; polycarbonate polyols and copolymers such as polyhexamethylene carbonate diol, poly(3-methyl-1,5-pentylene carbonate) diol, polypentamethylene carbonate diol, and polytetramethylene carbonate diol; and polyester carbonate polyols. Additionally, polyfunctional alcohols such as trifunctional alcohols or tetrafunctional alcohols, or short-chain alcohols such as ethylene glycol, may be used in combination as needed. These can be used individually or in combination of two or more types.

[0035] Specific examples of organic polyisocyanates include, for example, non-yellowing diisocyanates such as aliphatic or alicyclic diisocyanates like hexamethylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate; and aromatic diisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate. Polyfunctional isocyanates, such as trifunctional isocyanates, may also be used in combination as needed. These may be used individually or in combination of two or more.

[0036] Specific examples of chain extenders include, for example, diamines such as hydrazine, ethylenediamine, propylenediamine, hexamethylenediamine, nonamethylenediamine, xylylenediamine, isophoronediamine, piperazine and its derivatives, adipic acid dihydrazide, isophthalic acid dihydrazide; triamines such as diethylenetriamine; tetramines such as triethylenetetramine; diols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis(β-hydroxyethoxy)benzene, 1,4-cyclohexanediol; triols such as trimethylolpropane; and pentaerythritol. Tetraols Examples include amino alcohols such as aminoethyl alcohol and aminopropyl alcohol. These may be used individually or in combination of two or more.

[0037] Examples of crosslinking agents include difunctional polyisocyanate compounds that form crosslinked structures with hydroxyl groups or amino groups; polyfunctional isocyanate compounds such as biuret, adduct, and isocyanurate types; and compounds having carbodiimide, oxazoline, epoxy, cyclocarbonate, or aziridine groups, as well as hydrazine derivatives or hydrazide derivatives, which form crosslinked structures with carboxyl groups. These may be used individually or in combination of two or more. When using a crosslinking agent, the blending ratio of the crosslinking agent is preferably 2 to 20% by mass relative to the aqueous polyurethane.

[0038] Preferably, the surface layer, which is positioned as the outermost layer of the resin layer, contains at least polyurethane, a nonionic compound with an HLB value of 10-16, and a water-soluble polymer, and has a polar component of 25-40 mJ / m³ as analyzed by the OWRK method. 2 The dispersion component is 30-40 mJ / m³. 2 It is a layer having a surface free energy. Preferably, the surface layer consists of 90% by mass or more, and more preferably 95% by mass or more, aqueous polyurethane resin components.

[0039] Here, the surface free energy is the surface tension composed of the sum of the components of the intermolecular forces possessed by the solid. Also, the polar component and the dispersion component of the surface free energy analyzed by the Owens-Wendt-Rabel-Kaelble method (OWRK method) are, respectively, the components of the intermolecular forces of the surface free energy analyzed by the OWRK method. The polar component reflects the orientation force of the solid, and the dispersion component reflects the dispersion force of the solid.

[0040] The skin layer of this embodiment has a surface free energy in which the polar component analyzed by the OWRK method is 25 to 40 mJ / m 2 and the dispersion component is 30 to 40 mJ / m 2 By having such polar and dispersion components of the surface free energy in the skin layer, a silver-coated leather-like sheet excellent in the balance between water resistance and wettability can be obtained.

[0041] When the polar component of the surface free energy of the skin layer is less than 25 mJ / m 2 , the wettability tends to decrease. Also, when the polar component of the surface free energy of the skin layer exceeds 40 mJ / m 2 , the secondary adhesiveness tends to decrease. When the dispersion component of the surface free energy of the skin layer is less than 30 mJ / m 2 , the secondary adhesiveness tends to decrease. Also, when the dispersion component of the surface free energy of the skin layer exceeds 40 mJ / m 2 , the wettability tends to decrease.

[0042] The skin layer having such a surface free energy can be obtained by adjusting the type of polyurethane contained in the skin layer and the types and addition ratios of the nonionic compound having an HLB value of 10 to 16 and the water-soluble polymer added to adjust the surface free energy of the skin layer.

[0043] As the polyurethane contained in the skin layer, the polar component is 3 to 25 mJ / m 2 , and further 10 to 20 mJ / m 2 , and the dispersion component is 30 to 40 mJ / m 2It is preferable to use an aqueous polyurethane having a surface free energy such as [specified surface free energy]. Here, the surface free energy of polyurethane refers to the surface free energy of polyurethane that does not contain nonionic compounds or water-soluble polymers with an HLB value of 10 to 16.

[0044] The polar and dispersion components of the surface free energy of polyurethane can be altered by adjusting the ratio of hydrophilic to hydrophobic components in the soft segments derived from the polymeric polyol units of polyurethane.

[0045] Specifically, increasing the proportion of hydrophilic components in a polymer polyol increases the polar components, while increasing the proportion of hydrophobic components increases the dispersion components. Furthermore, a large polar component in the surface free energy of polyurethane also increases the polar component in the surface free energy of the epidermal layer, and a large dispersion component also increases the dispersion component in the surface free energy of the epidermal layer.

[0046] The hydrophilic component of the soft segment originates from polymeric polyol units, which have 1 to 3 carbon atoms in a repeating structure excluding ester bonds. Specific examples of polymeric polyols that constitute such hydrophilic components include, for example, polymeric polyols with 2 carbon atoms such as polyethylene glycol, and polymeric polyols with 3 carbon atoms such as polypropylene glycol.

[0047] The hydrophobic component of the soft segment originates from polymeric polyol units with 4 to 6 carbon atoms in the repeating structure excluding ester bonds. Specific examples of polymeric polyols that constitute such hydrophobic components include, for example, polymeric polyols with 4 carbon atoms such as polytetramethylene glycol, polymeric polyols with 5 carbon atoms such as polypentamethylene glycol, and polymeric polyols with 6 carbon atoms such as polyhexamethylene carbonate diol.

[0048] The polar component of the surface free energy of polyurethane, adjusted as described above, is 3-25 mJ / m 2 Furthermore, 10-20 mJ / m2 This is preferable because it maintains water resistance while also exhibiting excellent secondary adhesion. If the polar component of the surface free energy of polyurethane is too small, the polar component of the surface layer also decreases, which tends to reduce adhesion to adhesives and thermoplastic urethane resins, and thus reduce secondary adhesion. Conversely, if the polar component of the surface free energy of polyurethane is too large, the polar component of the surface layer also increases, which improves secondary adhesion but tends to reduce water resistance.

[0049] Furthermore, the dispersion component of the surface free energy of polyurethane is 30-40 mJ / m 2 This is preferable because it offers an excellent balance between water resistance and secondary adhesion. If the dispersion component of the surface free energy of polyurethane is too small, secondary adhesion tends to decrease.

[0050] Specific examples of such polyurethanes include water-based polyurethanes found in polyurethane emulsions such as Hydran ULK-190 and Hydran ULK-003 manufactured by DIC Corporation.

[0051] The epidermal layer contains nonionic compounds with an HLB value of 10-16. The HLB value (Hydrophilic-Lipophilic Balance) represents the degree of affinity of a surfactant to water and oil. The HLB value ranges from 0 to 20, with values ​​closer to 0 indicating higher lipophilicity and values ​​closer to 20 indicating higher hydrophilicity. By incorporating nonionic compounds with an HLB value of 10-16 into the epidermal layer, the surface free energy of the epidermal layer can be increased, improving the wettability required when surface treating the epidermal layer. The HLB value can be calculated, for example, using the Griffin method, from HLB value = 20 × (sum of molecular weights of hydrophilic parts / total molecular weight).

[0052] By incorporating nonionic compounds with an HLB value of 10-16 into the epidermal layer, the polarity component on the surface of the epidermal layer can be increased, thereby improving wettability. On the other hand, even if nonionic compounds with an HLB value of 10-16 are incorporated into the epidermal layer, secondary adhesion is not easily improved.

[0053] When the HLB value of a nonionic compound is less than 10, the low hydrophilicity of the nonionic compound makes it difficult for the polar component of the surface free energy of the epidermal layer to become sufficiently large. Conversely, when the HLB value of a nonionic compound exceeds 16, the high hydrophilicity of the nonionic compound tends to reduce the water resistance of the epidermal layer.

[0054] Specific examples of nonionic compounds with an HLB value of 10 to 16 include, for example, silicone compounds such as polysiloxanes like polyether-modified polydimethylsiloxane, acetylene glycol compounds, polyoxyethylene alkyl ether compounds, polyoxyethylene alkyl allyl ether compounds, polyoxyethylene-polyoxypropylene block copolymer compounds, or fluorine compounds such as organic fluoro compounds, all of which have an HLB value of 10 to 16. These may be used individually or in combination of two or more. Among these, silicone compounds or acetylene glycol compounds, and especially polyether-modified polydimethylsiloxane compounds, are preferred because they can significantly improve the surface free energy with the addition of small amounts.

[0055] The content of nonionic compounds with an HLB value of 10 to 16 in the epidermal layer is preferably 0.8 to 5.0% by mass, and more preferably 1.2 to 4.0% by mass. If the content of nonionic compounds with an HLB value of 10 to 16 is too low, the surface free energy of the epidermal layer does not improve sufficiently, and wettability tends not to improve sufficiently. On the other hand, if the content of nonionic compounds with an HLB value of 10 to 16 is too high, there is a concern that the nonionic compounds may bleed onto the surface of the epidermal layer, reducing water resistance and secondary adhesion.

[0056] Furthermore, the epidermal layer contains a water-soluble polymer. Because the water-soluble polymer has a large polar component of surface free energy, it easily penetrates the molecular network of aqueous polyurethane contained in the epidermal layer. This increases the polar component of the epidermal layer and improves secondary adhesion.

[0057] As mentioned above, the polar component of polyurethane can be increased by increasing the proportion of hydrophilic components in the soft segments of polyurethane. However, if the proportion of hydrophilic components in the soft segments of polyurethane is increased too much and the polar component is increased too much, the polyurethane will swell more easily with water, reducing its water resistance. In the surface layer of this embodiment, by incorporating a water-soluble polymer, secondary adhesion can be selectively improved without increasing the polar component of polyurethane too much and reducing its water resistance.

[0058] Water-soluble polymers are polymers that, when mixed with water, allow for the preparation of a solution in which 10 g or more is dissolved in 1 L of water. Specific examples include polyurethane-modified polyoxyalkylene, polyethylene glycol, polyvinyl alcohol, and polyvinylpyrrolidone. These may be used individually or in combination of two or more. Among these, polyurethane-modified polyoxyalkylene is particularly preferred because its strong interaction with aqueous polyurethane allows it to easily penetrate the molecular network of polyurethane contained in the epidermal layer, thereby increasing the polarity of the epidermal layer.

[0059] The number-average molecular weight of the water-soluble polymer is 10,000 or more, preferably between 10,000 and 150,000, and more preferably between 30,000 and 120,000. If the number-average molecular weight is too low, the effect of improving secondary adhesion tends to be small. Conversely, if the number-average molecular weight is too high, the water resistance tends to decrease.

[0060] The water-soluble polymer content in the epidermal layer is preferably 1.0 to 10% by mass, and more preferably 2.0 to 8.0% by mass. If the water-soluble polymer content is too low, the polar component of the surface free energy of the epidermal layer tends not to be sufficiently large. Conversely, if the water-soluble polymer content is too high, there is a concern that the water resistance of the epidermal layer will decrease.

[0061] The epidermal layer may optionally contain additives such as defoaming agents, leveling agents, thickeners, pigments, dyes, matting agents, organic solvents, and resin beads, to the extent that they do not impair the effects of the present invention.

[0062] The thickness of the epidermal layer is not particularly limited, but is preferably 10 to 100 μm, and more preferably 10 to 50 μm. The thickness of the epidermal layer can be calculated, for example, from cross-sectional images taken with a scanning electron microscope (SEM).

[0063] Furthermore, it is preferable for the epidermal layer to be a continuous film without pores, as this results in an elegant appearance without any depressions or indentations on the surface of the epidermal layer. If the epidermal layer has pores, when processed into a secondary product, depressions or indentations may form on the surface of the epidermal layer, resulting in an unsightly appearance.

[0064] The resin layer included in the full-grain leather-like sheet of this embodiment includes at least the surface layer described above, and may further include other resin-containing layers, such as an adhesive layer for bonding the surface layer to the fiber substrate, or an intermediate layer for adjusting the surface texture, as needed.

[0065] Next, an example of a method for manufacturing the full-grain leather-like sheet of this embodiment will be described. The method for manufacturing the full-grain leather-like sheet of this embodiment is the same as the conventional method for manufacturing a full-grain leather-like sheet, except that the resin layer that gives the full-grain appearance includes the surface layer described above.

[0066] For example, a fibrous substrate as described above is prepared, and a resin layer is formed on one surface of the fibrous substrate to give it a silvery appearance. Specifically, one example is a dry surface formation method in which a film that will become the resin layer formed on release paper is adhered to the surface of the fibrous substrate, and the resin layer is laminated and adhered to the fibrous substrate by peeling off the release paper.

[0067] Specifically, first, a coating solution for forming the epidermal layer is applied to the release paper, and a film that will become the epidermal layer is formed by drying.

[0068] The coating solution for the epidermal layer is a mixture of an aqueous polyurethane liquid, such as an emulsion or dispersion containing aqueous polyurethane, a nonionic compound with an HLB value of 10 to 16, a water-soluble polymer, and crosslinking agents and additives as needed. It is preferable that the water-soluble polymer and the nonionic compound with an HLB value of 10 to 16 be included in liquid form, such as an aqueous solution or oil, as this facilitates mixing.

[0069] The concentration of solids in the aqueous polyurethane solution is not particularly limited, but is preferably about 20 to 60% by mass. Similarly, the concentration of solids in the aqueous solution of the water-soluble polymer is not particularly limited, but is preferably about 20 to 60% by mass.

[0070] Next, the coating liquid for the surface layer is applied to the release paper and dried. The drying conditions are not particularly limited, but conditions such as drying at 70 to 130°C for 1 to 10 minutes are preferred. In this way, a film that will become the surface layer is formed on the release paper.

[0071] Then, a film that will form an intermediate layer or adhesive layer is formed on the surface of the film that will form the surface layer on the release paper. The resin used to form the intermediate layer or adhesive layer is not particularly limited, but polyurethane is preferred because it has excellent adhesion to other layers. Furthermore, aqueous polyurethane is particularly preferred because it can reduce the amount of organic solvent used.

[0072] The polyurethane used in the adhesive layer may be a solvent-based polyurethane dissolved in an organic solvent, or it may be an aqueous polyurethane, but an aqueous polyurethane is preferred because it can reduce the amount of organic solvent used. Furthermore, it is preferable to incorporate a crosslinking agent into the adhesive layer to improve adhesion to the substrate.

[0073] Any known polyurethane crosslinking agent can be used as the crosslinking agent for the polyurethane used in the adhesive layer, without any particular limitations. Specifically, examples include epoxy compounds, aziridine compounds, carbodiimide compounds, organic polyisocyanate compounds, oxazoline compounds, melamineformamide compounds, ureamethylol compounds, etc. These may be used individually or in combination of two or more.

[0074] Furthermore, the intermediate layer is a layer that is added as needed to adjust the thickness of the grain-like resin layer of the grain-like leather sheet. The polyurethane used in the intermediate layer may be a solvent-based polyurethane dissolved in an organic solvent, or it may be an aqueous polyurethane, but an aqueous polyurethane is preferred because it can reduce the amount of organic solvent used.

[0075] The adhesive layer is formed by applying an adhesive coating solution to the surface of the film that will become the surface layer, which is formed on the release paper, and drying it. When forming an intermediate layer, the intermediate layer is formed by applying an intermediate layer coating solution to the surface of the film that will become the surface layer, which is formed on the release paper, and drying it. When an intermediate layer is formed, the adhesive layer is formed by applying an adhesive coating solution to the surface of the film formed by laminating the surface layer and the intermediate layer, and drying it. Each layer may be a single layer or consist of multiple layers formed from coating solutions of different compositions. The film that will become the intermediate layer and the film that will become the adhesive layer are formed in the same way as the film that will become the surface layer.

[0076] The thickness of the intermediate layer is not particularly limited, but is preferably 10 to 50 μm, and more preferably 20 to 40 μm. Similarly, the thickness of the adhesive layer is not particularly limited, but is preferably 30 to 130 μm, and more preferably 50 to 100 μm.

[0077] Then, the resulting laminate (adhesive layer / surface layer / release paper, or adhesive layer / intermediate layer / surface layer / release paper) is laminated onto the surface of a fiber substrate via the adhesive layer, and pressed with a clearance roll or the like to adhere the resin layer to the surface of the fiber substrate. If necessary, the crosslinking of the polyurethane contained in the adhesive layer may be promoted by aging at 40-90°C for 1-3 days. By peeling off the release paper from the laminate obtained in this way, a silver-plated leather-like sheet is obtained.

[0078] The resulting grain-plated leather-like sheet exhibits excellent processability for secondary products such as shoes, bags, and clothing. Specifically, when a treatment solution containing pigments, matting agents, antibacterial agents, etc., is applied to the surface of the resin layer by gravure coating or the like, it shows excellent wettability to highly polar water-based treatment solutions. Furthermore, when other materials are bonded to the surface of the resin layer with an adhesive, it exhibits particularly excellent adhesion to adhesives containing water-based polyurethane and hot-melt polyurethane adhesives. [Examples]

[0079] The present invention will be described in more detail below with reference to examples. However, the scope of the present invention is not limited in any way to the examples. In the following, parts and percentages are based on mass unless otherwise specified.

[0080] First, the evaluation methods used in the examples are summarized below.

[0081] [Calculation of polar and dispersion components of surface free energy of polyurethane and epidermal layer] Using pure water and diiodomethane (methylene iodide) as test solutions, the polar and dispersion components of the surface free energy of polyurethane and the epidermal layer were analyzed by the OWRK method. Specifically, regarding the surface free energy of polyurethane, a polyurethane emulsion was poured into a mold of a predetermined size lined with release paper having a smooth surface, and the emulsion was dried to form a polyurethane film approximately 50 mm thick. Then, 1 μL droplets of pure water and diiodomethane were dropped onto the surface of the polyurethane film using a syringe, and the contact angle with each droplet was measured using a contact angle meter (CA-DT, manufactured by Kyowa Interface Science Co., Ltd.). The measurement environment was 25°C and 50 RH. Then, by solving the simultaneous equations using the following equation (1) based on OWRK analysis, the polar component γ of the surface free energy of the polyurethane film surface is obtained. p and dispersion component γ d The following was calculated. 1 + cosθ = 2[(γ d ·γ L d ) / γ L 2 ] 1 / 2 +2[(γ p ·γ L p ) / γ L 2 ] 1 / 2 ...Equation (1) Each symbol in equation (1) has the following meanings: ·γ d : Dispersion component of the surface free energy of the polyurethane film surface (mJ / m 2 ) ·γ p : Polar component of the surface free energy of the polyurethane film surface (mJ / m 2 ) • θ: Contact angle of each test solution (°) ·γ L d : Dispersion component of the surface free energy of each test solution (mJ / m 2 )(Water:21.8mJ / m 2 Diiodomethane: 49.5 mJ / m³ 2 ) ·γ L p : Polar component of the surface free energy of each test solution (mJ / m 2 )(Water:51.0mJ / m 2 Diiodomethane: 1.3 mJ / m³ 2 ) ·γ L : Surface free energy of the test solution Similarly, a film was formed using a coating solution for the surface layer of a silver-plated leather-like sheet, the contact angles of the surface layer with respect to pure water and diiodomethane were measured, and the polar component γ of the surface free energy of the surface layer of the silver-plated leather-like sheet was determined using equation (1) based on OWRK analysis. p and dispersion component γ d The following was calculated.

[0082] [Number average molecular weight of water-soluble polymers] The number-average molecular weight was determined by gel permeation chromatography (GPC) measurement under the following conditions, and the value was calculated as a standard polystyrene equivalent. (GPC measurement conditions) Device: "CBM-20A", manufactured by Shimadzu Corporation Mobile phase: N,N-dimethylformamide (flow rate: 1 mL / min) Column: Shodex KD-806M Detector: Differential refractometer Measurement temperature: 40℃ Standard material: Polystyrene, manufactured by Tosoh Corporation Injection volume: 50μL Sample concentration: 2 mg / 2 cc

[0083] [Water resistance of the epidermal layer] A 3cm x 3cm film piece was cut from the film forming the surface layer of the grain-plated leather-like sheet. The film piece was then immersed in 25°C water for 24 hours, and then removed. The weight of the film piece was measured after wiping off excess water immediately after removal, and the weight swelling rate (%) was calculated according to the following formula. Weight swelling rate (%) = {(Weight after swelling - Weight before immersion) / Weight before immersion} × 100 Based on the obtained weight swelling rate, water resistance was determined according to the following evaluation criteria. Excellent: Weight swelling rate is less than 5% Good: Weight swelling rate of 5% or more, but less than 15% Inferior: Weight swelling rate of 15% or more

[0084] [Wettability of the epidermal surface] The wettability of the surface layer of the silver-plated leather-like sheet was measured in accordance with JIS K6768. Specifically, a wettability test mixture (manufactured by Kanto Chemical Co., Ltd.: 65 mJ / m²) was applied to the surface of the surface layer of the silver-plated leather-like sheet. 2 The liquid film was coated to a wet film thickness of 12 μm using a non-wire bar coater. The liquid film was evaluated as "high" if it did not break for 5 seconds or more, "medium" if it broke between 2 seconds and 5 seconds, and "low" if it broke in less than 2 seconds.

[0085] [Secondary adhesion to the surface of the epidermal layer] We prepared silver-plated leather-like sheets, hot-melt tape, and plain-woven fabric, each cut into strips measuring 150mm x 30mm. For the hot-melt tape, we used a 200μm thick thermoplastic urethane hot-melt tape (NASA-T from Sambu Fine Chemical). The plain-woven fabric had a weight of 1.3g / m². 2 That was the case. Then, a stack of hot melt tape and plain weave fabric is sequentially laminated on the surface of the outer layer of a silver-plated leather-like sheet, and then heated at a temperature of 130°C to a density of 6 kgf / cm². 2 Test specimens were prepared by applying pressure for 30 seconds. Note that on one end only, a 30mm area in the vertical direction from the end was left unbonded, while the remaining 120mm area in the vertical direction was bonded.

[0086] Then, the peel strength of the hot melt tape adhered to the surface of the surface layer of the silver-plated leather-like sheet was measured using a tensile testing machine. Specifically, one end of the silver-plated leather-like sheet that was not adhered and one end of the plain weave fabric that was not adhered were clamped in the upper and lower chucks of the tensile testing machine, respectively, and the peel strength between the hot melt tape and the surface of the surface layer was measured at a test speed of 50 mm / min. The samples were then judged as follows: "Excellent" if the peel strength was 3.0 kg / cm or higher and the epidermal layer was fractured and peeled off; "Good" if the peel strength was 3.0 kg / cm or higher but no material fracture occurred in the epidermal layer; and "Poor" if the peel strength was less than 3.0 kg / cm.

[0087] Furthermore, the raw materials used in this embodiment are summarized below.

[0088] (Polyurethane emulsion for the epidermal layer) • Polyurethane A emulsion: Polyether-based polyurethane emulsion with 35% solids content (Hydran ULK-190, manufactured by DIC Corporation) • Polyurethane B emulsion: Polyether-based polyurethane emulsion with 30% solids content (Hydran ULK-003, manufactured by DIC Corporation) • Polyurethane C emulsion: Polyester / polyether-based polyurethane emulsion with 45% solids content (Hydran CRS-086, manufactured by DIC Corporation) • Polyurethane D emulsion: An anionic, self-emulsifying polycarbonate-based polyurethane emulsion with 40% solids content (100% modulus 3.0 MPa) • Polyurethane E emulsion: A polycarbonate-based polyurethane emulsion with 30% solids content (Hydran WLS-290SG, manufactured by DIC Corporation)

[0089] (Polyurethane emulsion for adhesive layer) • Emulsion of polyether-based polyurethane with a solid content of 55% (Hydran WLA-451TA, manufactured by DIC Corporation)

[0090] (Nonionic compounds) Nonionic compound E: Silicone-based compound with an HLB value of 12 (polyether-modified polydimethylsiloxane, silicone oil KF-351A manufactured by Shin-Etsu Chemical Co., Ltd.) Nonionic compound F: Silicone-based compound with an HLB value of 10 (polyether-modified polydimethylsiloxane, silicone oil KF-353 manufactured by Shin-Etsu Chemical Co., Ltd.) Nonionic compound G: Silicone-based compound with an HLB value of 16 (polyether-modified polydimethylsiloxane, manufactured by Shin-Etsu Chemical Co., Ltd., silicone oil KF-354L) • Nonionic compound H:HLB value = 7 silicone-based compound (polyether-modified polydimethylsiloxane, silicone oil KF-352A manufactured by Shin-Etsu Chemical Co., Ltd.) Nonionic compound I: Acetylene glycol-based nonionic surfactant with an HLB value of 13 (Surfinol 465, manufactured by Nisshin Chemical Industry Co., Ltd.) Nonionic compound X: Polyoxyethylene alkyl ether-based nonionic compound with an HLB value of 18 (NIKKOL BC-23, manufactured by Nikko Chemicals Co., Ltd.)

[0091] (Aqueous solution of water-soluble polymer) • Aqueous solution of water-soluble polymer J: Aqueous solution of polyether polyol-based urethane polymer (polyurethane-modified polyoxyalkylene) with a number average molecular weight of 68,000 (solid content 47.6%, Adekanol UH-541VF, ADEKA Corporation) • Aqueous solution of water-soluble polymer K: Aqueous solution of polyethylene glycol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) with a number average molecular weight of 20,000, diluted to a solid content of 50%. • Aqueous solution of water-soluble polymer L: A aqueous solution of polyethylene oxide (Alcox L-11 from Meisei Chemical Industry Co., Ltd.) with a number average molecular weight of 110,000, diluted to a solid content of 50%. • Aqueous solution of water-soluble polymer M: Aqueous solution of polyethylene glycol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) with a number average molecular weight of 8,000, diluted to a solid content of 50%. • Aqueous solution of water-soluble polymer Y: Aqueous solution of polyethylene glycol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) with a number-average molecular weight of 500,000, diluted to a solid content of 50%.

[0092] (Fiber base material) This nonwoven fabric contains polyethylene terephthalate (PET) fibers with an average fineness of 0.1 dtex and polyurethane impregnated into the nonwoven fabric, with a PET / polyurethane ratio of 90 / 10 and a basis weight of 530 g / m². 2 A 1mm thick fiber base material.

[0093] [Example 1] The above-mentioned raw materials were mixed to prepare a coating solution for the epidermal layer and a coating solution for the adhesive layer, so that the solid content had the following composition. (Coating liquid for epidermal layer) • Polyurethane A 100 parts (95.5%) (parts by mass (mass%), the same applies hereafter) Nonionic compound E 1.4 parts (1.3%) • Water-soluble polymer J 3.4 parts (3.2%) (Coating liquid for adhesive layer) • Polyurethane for adhesive layer, 100 units • Crosslinking agent 17 parts • Leveling agent 0.5 part • Thickening agent 0.5 part

[0094] Then, on the release surface of the release paper, the amount of wet material adhering to it is 120g / m². 2 A coating solution for the epidermal layer was applied, and the film for the epidermal layer was prepared by heating and drying it in a 90°C dryer for 5 minutes. Then, a wet coating amount of 130 g / m² was applied to the surface of the epidermal layer film. 2 The adhesive layer film was laminated by applying an adhesive coating solution and drying it in a 90°C dryer for 5 minutes. The laminate of the surface layer film and the adhesive layer film, formed on the release paper, was then placed on the surface of the fiber substrate with the adhesive layer film facing each other, and pressed with a flat plate hot press to bond the fiber substrate and the laminate. The pressing was performed at a temperature of 100°C, a pressure of 5 kgf / cm, and for 10 seconds. After pressing, the polyurethane adhesive layer was further aged at 70°C for 72 hours to promote crosslinking.

[0095] Then, by peeling off the release paper from the laminate obtained in this way, a silver-plated leather-like sheet of Example 1 was obtained, comprising a fibrous base material and a resin layer including a surface layer laminated on one surface of the fibrous base material. The obtained silver-plated leather-like sheet had a surface layer with a thickness of 50 μm, a thickness of 0.1 mm, and a basis weight of 640 g / m². 2 The evaluations were then conducted according to the evaluation method described above. The results are shown in Table 1 below.

[0096] [Table 1]

[0097] [Example 2] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (95.5%) Nonionic compound E 1.4 parts (1.3%) • Water-soluble polymer K 3.4 parts (3.2%)

[0098] [Example 3] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (95.5%) Nonionic compound E 1.4 parts (1.3%) • Water-soluble polymer L 3.4 parts (3.2%)

[0099] [Example 4] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (95.9%) Nonionic compound E 0.8 parts (0.8%) • Water-soluble polymer J 3.4 parts (3.3%)

[0100] [Example 5] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (92.6%) Nonionic compound E 4.5 parts (4.2%) • Water-soluble polymer J 3.4 parts (3.2%)

[0101] [Example 6] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (95.5%) Nonionic compound F 1.4 parts (1.3%) • Water-soluble polymer J 3.4 parts (3.2%)

[0102] [Example 7] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (95.5%) Nonionic compound G 1.4 parts (1.3%) • Water-soluble polymer J 3.4 parts (3.2%)

[0103] [Example 8] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (95.5%) Nonionic compound I 1.4 parts (1.3%) • Water-soluble polymer J 3.4 parts (3.2%)

[0104] [Example 9] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (97.1%) Nonionic compound E 1.4 parts (1.4%) • Water-soluble polymer J 1.5 parts (1.5%)

[0105] [Example 10] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (90.1%) Nonionic compound E 1.4 parts (1.3%) • Water-soluble polymer J 9.5 parts (8.6%)

[0106] [Example 11] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane B 100 parts (94.4%) Nonionic compound E 2.5 parts (2.4%) • Water-soluble polymer J 3.4 parts (3.2%)

[0107] [Example 12] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane C 100 parts (95.5%) Nonionic compound E 1.4 parts (1.3%) • Water-soluble polymer J 3.4 parts (3.2%)

[0108] [Example 13] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (97.9%) Nonionic compound E 1.4 parts (1.4%) • Water-soluble polymer J 0.7 parts (0.7%)

[0109] [Example 14] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (90.2%) Nonionic compound E 1.4 parts (1.2%) • Water-soluble polymer M 9.5 parts (8.6%)

[0110] [Comparative Example 1] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (96.1%) Nonionic compound E 0.6 parts (0.6%) • Water-soluble polymer J 3.4 parts (3.3%)

[0111] [Comparative Example 2] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (92.3%) Nonionic compound H 5.0 parts (4.6%) • Water-soluble polymer J 3.4 parts (3.1%)

[0112] [Comparative Example 3] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane D 100 parts (90.1%) Nonionic compound E 1.4 parts (1.3%) • Water-soluble polymer J 9.5 parts (8.6%)

[0113] [Comparative Example 4] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (100%)

[0114] [Comparative Example 5] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (96.7%) • Water-soluble polymer J 3.4 parts (3.3%)

[0115] [Comparative Example 6] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (99.4%) Nonionic compound E 0.6 parts (0.6%)

[0116] [Comparative Example 7] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (95.5%) Nonionic compound X 1.4 parts (1.3%) • Water-soluble polymer J 3.4 parts (3.2%)

[0117] [Comparative Example 8] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (95.5%) Nonionic compound E 1.4 parts (1.3%) • Water-soluble polymer Y 3.4 parts (3.2%)

[0118] [Comparative Example 9] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane A 100 parts (87.8%) Nonionic compound E 4.5 parts (3.9%) • Water-soluble polymer J 9.5 parts (8.3%)

[0119] [Comparative Example 10] A silver-plated leather-like sheet was prepared and evaluated in the same manner as in Example 1, except that a coating solution for the epidermal layer was used, prepared so that the solid content had the following composition. The results are shown in Table 1. • Polyurethane E 100 parts (92.3%) • Nonionic compound H 5 parts (4.6%) • Water-soluble polymer J 3.4 parts (3.1%)

[0120] Referring to Table 1, the present invention comprises polyurethane, a nonionic compound with an HLB value of 10 to 16, and a water-soluble polymer, with a polar component of 25 to 40 mJ / m³. 2 The dispersion component is 30-40 mJ / m³. 2 The silver-plated leather-like sheets obtained in Examples 1 to 14, which had the above-mentioned surface layer, all exhibited a wettability of "medium" or higher, water resistance of "good" or higher, and secondary adhesion of "good" or higher.

[0121] On the other hand, the polar component is 25 mJ / m³ due to the low proportion of nonionic compounds. 2 The silver-plated leather-like sheet obtained in Comparative Example 1, which had an HLB value of less than 10, had low wettability. Furthermore, the silver-plated leather-like sheet obtained in Comparative Example 2, which used a nonionic compound with an HLB value of less than 10, maintained a polar component level of 25 mJ / m³ even with a high proportion of the nonionic compound. 2Because it was less than 25 mJ / m³, the wettability was low. Also, the silver-plated leather-like sheet obtained in Comparative Example 3, which used aqueous polyurethane with low polarity and dispersion components, also had a polarity component of 25 mJ / m³ even when a large amount of water-soluble polymer was added. 2 Less than 30 mJ / m³ of dispersion component 2 Because the value was less than [value missing], it had low wettability and poor secondary adhesion.

[0122] Furthermore, it does not contain nonionic compounds or water-soluble polymers, and the polar component is 25 mJ / m³. 2 The silver-plated leather-like sheet obtained in Comparative Example 4, which was less than [amount missing], had excellent water resistance, but poor wettability and also poor secondary adhesion.

[0123] Furthermore, compared to the silver-plated leather-like sheet obtained in Comparative Example 4, the silver-plated leather-like sheet obtained in Comparative Example 5, which had only a water-soluble polymer incorporated into the surface layer, also had a polar component of 25 mJ / m². 2 Because the value was less than [value missing], secondary adhesion improved, but wettability remained low.

[0124] Furthermore, the silver-plated leather-like sheet obtained in Comparative Example 6, which had only a nonionic compound incorporated into the surface layer compared to the silver-plated leather-like sheet obtained in Comparative Example 4, also had a polar component of 25 mJ / m². 2 Because the value was less than [value missing], secondary adhesion improved, but wettability remained low.

[0125] Furthermore, the silver-plated leather-like sheet obtained in Comparative Example 7, which used a nonionic compound with an HLB value exceeding 16 in the epidermal layer, also had a polar component of 25 mJ / m². 2 Because the value was less than 25 mJ / m², wettability improved, but water resistance and secondary adhesion decreased. Furthermore, the silver-plated leather-like sheet obtained in Comparative Example 8, which used a water-soluble polymer with a high number-average molecular weight, also had a polar component of 25 mJ / m². 2 Because the value was less than [value missing], wettability improved, but water resistance and secondary adhesion decreased.

[0126] Furthermore, the silver-plated leather-like sheet obtained in Comparative Example 9, which contained a high proportion of a nonionic compound with an HLB value of 12 and a water-soluble polymer, had a polar component content of 40 mJ / m².2 Because it exceeded this value, wettability improved, but water resistance and secondary adhesion decreased. In addition, the silver-plated leather-like sheet obtained in Comparative Example 10, which used aqueous polyurethane with a high dispersion component, also had a dispersion component of 40 mJ / m 2 Because it exceeded the limit, water resistance improved, but wettability and secondary adhesion decreased. [Explanation of Symbols]

[0127] 1. Fiber base material 2 resin layers 2a Epidermal layer 2b Middle layer 2c adhesive layer 10. Silver-plated leather-like seat

Claims

1. The system comprises a fibrous base material and a resin layer laminated on one surface of the fibrous base material, The aforementioned resin layer includes at least a surface layer, The aforementioned epidermal layer is The material comprises polyurethane, a nonionic compound with an HLB value of 10-16, and a water-soluble polymer, and its polar component, as analyzed by the Owens-Wendt-Rabel-Kaelble method, has a concentration of 25-40 mJ / m³. 2 The dispersion component is 30-40 mJ / m³. 2 A silver-plated leather-like sheet having a surface free energy.

2. The aforementioned polyurethane was analyzed by the Owens-Wendt-Rabel-Kaelble method, and its polar component was found to be 5 to 20 mJ / m³. 2 The dispersion component is 30-40 mJ / m³. 2 A silver-plated leather-like sheet according to claim 1, having a surface free energy.

3. The silver-plated leather-like sheet according to claim 1 or 2, wherein the polyurethane is an aqueous polyurethane.

4. The silver-plated leather-like sheet according to claim 1 or 2, wherein the nonionic compound comprises at least one of a silicone compound and an acetylene glycol compound.

5. The silver-plated leather-like sheet according to claim 1 or 2, wherein the surface layer contains 0.8 to 5.0% by mass of the nonionic compound.

6. The silver-plated leather-like sheet according to claim 1 or 2, wherein the water-soluble polymer has a number average molecular weight of 10,000 to 150,000.

7. The silver-plated leather-like sheet according to claim 1 or 2, wherein the surface layer contains 1.0 to 10% by mass of the water-soluble polymer.

8. The silver-plated leather-like sheet according to claim 1 or 2, wherein the water-soluble polymer comprises a polyurethane-modified polyoxyalkylene.

9. The aforementioned surface layer is a continuous film having no pores and having a thickness of 10 to 100 μm, wherein the silver-plated leather-like sheet is as described in claim 1 or 2.

10. The silver-plated leather-like sheet according to claim 1 or 2, wherein the resin layer includes an adhesive layer containing polyurethane, having a thickness of 30 to 120 μm, for bonding the fiber substrate.

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