Synthetic leather

Abstract

A synthetic leather according to an embodiment of the present invention comprises a fibrous substrate, a foam layer that contains a vinyl chloride resin and a plasticizer, and a non-foam layer that contains a vinyl chloride resin and a plasticizer. In the foam layer and the non-foam layer, the content of the plasticizer is 60-100 parts by mass with respect to 100 parts by mass of the vinyl chloride resin, the plasticizer contains a phthalic acid ester plasticizer and a polyester plasticizer, and the mass ratio of the phthalic acid ester plasticizer and the polyester plasticizer is 73:27 to 87:13.

Description

Technical Field

[0001] The present invention relates to synthetic leather.

Background Art

[0002] Among synthetic leathers, synthetic leather having a film mainly composed of a vinyl chloride resin has flexibility such as high flexibility and softness, and strength. Examples of the strength include abrasion resistance against repeated rubbing phenomena. Synthetic leather is used in various fields such as vehicle interior materials such as vehicle seats and door linings, interior materials such as furniture and chairs, and fashion applications such as bags and shoes. Since these applications are placed in harsh usage conditions, high durability is required. In particular, in the case of synthetic leather used in places where there are many opportunities to directly or indirectly touch the human body, oil resistance against sebum secreted from the human body and oily components contained in cosmetics is required. In particular, strong durability against higher fatty acids such as oleic acid, which is the main component of sebum, is strongly required.

[0003] For example, Patent Document ① describes forming a surface treatment layer by applying a surface treatment agent formed by crosslinking a mixture of polycarbonate urethane and ester urethane with a carbodiimide group-containing crosslinking agent on the surface side of a film mainly composed of a vinyl chloride resin. Patent Document ① describes that by forming the surface treatment layer, in addition to high flexibility and good strength, abrasion resistance against repeated rubbing phenomena and improvement in chemical resistance (oleic acid resistance) against human contact can be achieved.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] While the synthetic resin leather described in Patent Document 1 has good chemical resistance (resistance to oleic acid), higher oil resistance is required.

[0006] On the other hand, from the perspective of reducing costs and ensuring a certain level of quality, synthetic leather needs to have a structure that is easy to manufacture, that is, it needs to be easy to process (or manufacture).

[0007] This invention has been made in view of the current situation, and its purpose is to provide synthetic leather with excellent oil resistance and processability. [Means for solving the problem]

[0008] The synthetic leather according to an embodiment of the present invention comprises, in this order, a fibrous base material, a foamed layer containing a vinyl chloride resin and a plasticizer, and a non-foamed layer containing a vinyl chloride resin and a plasticizer. In each of the foamed layer and the non-foamed layer, the content of the plasticizer is 60 to 100 parts by mass per 100 parts by mass of the vinyl chloride resin, and the plasticizer comprises a phthalate ester plasticizer and a polyester plasticizer, and the mass ratio of the phthalate ester plasticizer to the polyester plasticizer is 73:27 to 87:13. [Effects of the Invention]

[0009] According to embodiments of the present invention, it is possible to provide synthetic leather with excellent oil resistance and processability. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view of synthetic leather according to one embodiment. [Figure 2] This is a schematic cross-sectional view of synthetic leather according to another embodiment. [Figure 3] This is a schematic cross-sectional view of synthetic leather according to another embodiment. [Modes for carrying out the invention]

[0011] The synthetic leather according to this embodiment comprises a fibrous base material, a foamed layer containing a vinyl chloride resin and a plasticizer, and a non-foamed layer containing a vinyl chloride resin and a plasticizer. The foamed layer and the non-foamed layer contain 60 to 100 parts by mass of plasticizer per 100 parts by mass of vinyl chloride resin. The plasticizers used in the foamed layer and the non-foamed layer are phthalate ester plasticizers and polyester plasticizers, and the mass ratio of the phthalate ester plasticizer to the polyester plasticizer is 73:27 to 87:13. By adopting such a configuration, it is possible to produce a synthetic leather that has good oil resistance, good processability in the casting method, and a flexible texture.

[0012] Figure 1 schematically shows the cross-sectional structure of synthetic leather 1 according to one embodiment. In this synthetic leather 1, a foamed layer 3 and a non-foamed layer 4 are laminated in that order on one side of a fibrous base material 2.

[0013] Figure 2 schematically shows the cross-sectional structure of synthetic leather 10 according to another embodiment. This synthetic leather 10 differs from synthetic leather 1 in Figure 1 in that a foamed layer 3 is provided on a fibrous base material 2 via an adhesive layer 5, and a protective layer 6 is provided on a non-foamed layer 4. Therefore, in the example in Figure 2, the adhesive layer 5, foamed layer 3, non-foamed layer 4, and protective layer 6 are laminated in this order on one side of the fibrous base material 2.

[0014] Figure 3 schematically shows the cross-sectional structure of synthetic leather 100 according to another embodiment. This synthetic leather 100 differs from the synthetic leather 10 in Figure 2 in that a protective layer 6 is provided on the non-foamed layer 4 via an undercoat layer 7. Therefore, in the example in Figure 3, the adhesive layer 5, foamed layer 3, non-foamed layer 4, undercoat layer 7, and protective layer 6 are laminated in this order on one side of the fibrous base material 2.

[0015] In the examples shown in Figures 1-3, the front surface of the synthetic leather has textured surfaces, such as grain patterns, for aesthetic purposes, but it may also be flat. Here, the front surface of the synthetic leather refers to the side of the synthetic leather that is visible during use (the design side). Specifically, the front surface is the surface of the non-foamed layer or protective layer mentioned above.

[0016] The fibrous base material is not particularly limited, and for example, woven fabrics, knitted fabrics, nonwoven fabrics, and natural leather (including split leather) can be used. As for the fibrous fabric, a conventionally known solvent-based or solvent-free polymer compound may be applied or impregnated and then dry-coagulated or wet-coagulated. The solvent-free system here includes water-based systems. Examples of polymer compounds include polyurethane resins and vinyl chloride resins. Among these, knitted fabrics are preferred as the fibrous base material from the viewpoint of leather-like properties (specifically, a texture, thickness, and feel similar to natural leather), strength, and elongation characteristics, and circular knitted fabrics are more preferred.

[0017] In textile fabrics, the type of fiber is not particularly limited and can include conventionally known fibers such as natural fibers, regenerated fibers, semi-synthetic fibers, and synthetic fibers, and two or more of these may be combined. Among these, synthetic fibers are preferred in terms of strength and processability, and polyester fibers are more preferred.

[0018] The shape of the fibers is not particularly limited and may be either long fibers or short fibers. The form of the yarn constituting the fibrous base material may be short fiber yarn such as spun yarn, long fiber yarn such as multifilament yarn or monofilament yarn, or a long-short composite spun yarn combining long and short fibers. From the viewpoint of imparting flexibility to the resulting fibrous base material, short fibers that have been crimped in advance may be used as yarn, or the yarn may be subjected to processing such as false twisting or fluid disturbance treatment.

[0019] The fibrous base material may be colored with dyes or pigments.

[0020] The synthetic leather according to this embodiment includes a resin layer containing a vinyl chloride-based resin and a plasticizer, and includes a foamed layer and a non-foamed layer. The foamed layer is a resin layer having bubbles and may be a porous layer. Different from the foamed layer, the non-foamed layer is a resin layer having no bubbles. The non-foamed layer is a resin layer laminated on the surface of the foamed layer and is also referred to as an epidermis layer.

[0021] The vinyl chloride-based resin constituting the non-foamed layer is a polymer composed of vinyl chloride and / or vinylidene chloride as monomer components. The vinyl chloride-based resin is not particularly limited, and a conventionally known vinyl chloride-based resin can be used. For example, a vinyl chloride resin and / or a vinylidene chloride resin can be mentioned. Examples of the vinyl chloride resin include polyvinyl chloride which is a homopolymer of vinyl chloride, a copolymer of vinyl chloride and other monomers, and the like. Examples of the vinylidene chloride resin include polyvinylidene chloride which is a homopolymer of vinylidene chloride, a copolymer of vinylidene chloride and other monomers, and the like. These can be used alone or in combination of two or more. Here, examples of other monomers copolymerized with vinyl chloride or vinylidene chloride include vinyl acetate, ethylene, propylene, styrene, acrylic acid, acrylic ester, methacrylic acid, methacrylic ester, maleic acid, maleic ester, higher vinyl ether, and the like. Vinyl chloride and vinylidene chloride may be copolymerized.

[0022] The resin component constituting the non-foamed layer preferably has a vinyl chloride-based resin as the main component. Specifically, it is preferably that more than 50% by mass of the resin component is a vinyl chloride-based resin, more preferably 80% by mass or more of the resin component is a vinyl chloride-based resin, and 100% by mass of the resin component may be a vinyl chloride-based resin. In this specification, the resin component refers to a polymer component excluding additives such as a plasticizer and a heat stabilizer among the components constituting the resin layer.

[0023] The non-foaming layer contains a phthalate ester plasticizer and a polyester plasticizer as plasticizers. By using a combination of phthalate ester plasticizers and polyester plasticizers, the viscosity of the resin composition liquid for the non-foaming layer can be kept low. Therefore, the occurrence of bubbles and processing streaks can be suppressed, and a uniform film can be formed. Thus, processability, especially processability in the casting method, is improved. Here, processing streaks refer to streak-like defects that occur along the application direction when the resin composition liquid is applied. Polyester plasticizers have a larger molecular weight compared to other plasticizers. Therefore, by using polyester plasticizers, the diffusion rate of the plasticizer is reduced, and the plasticizer is less likely to migrate from the inside to the outside of the non-foaming layer. Thus, the oil resistance of the resulting synthetic leather can be improved.

[0024] Phthalate ester plasticizers refer to phthalate esters that act as plasticizers for vinyl chloride resins. Examples of phthalate ester plasticizers include dibutyl phthalate (DBP), dioctyl phthalate (DOP), dinonyl phthalate (DNP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), ditridecyl phthalate (DTDP), diundecyl phthalate (DUP), benzyl butyl phthalate (BBP), nonylundecyl phthalate (NUP), and dialkyl phthalates (C9-C11). These can be used individually or in combination of two or more. Since these are esters of phthalic acid and monohydric alcohol, phthalate-based polyesters, which will be discussed later as polyester plasticizers, are not included in the category of phthalate ester plasticizers.

[0025] In one embodiment, phthalate ester system As a plasticizer, dialkyl phthalates are preferred, which are esters of phthalic acid with at least one monohydric alcohol selected from the group consisting of alcohols having 4 to 20 carbon atoms. Among these, dialkyl phthalates (C9-C11) are preferred from the viewpoint of bleed resistance, cold resistance, and heat resistance. Here, dialkyl phthalates (C9-C11) are esters of phthalic acid with a mixture of alcohols having 9 to 11 carbon atoms.

[0026] Polyester plasticizers refer to polyesters that act as plasticizers for vinyl chloride resins. Examples of polyester plasticizers include those obtained by polycondensation of dicarboxylic acids and dihydric alcohols, such as adipic acid-based polyesters, sebaciate-based polyesters, and phthalic acid-based polyesters. These can be used individually or in combination of two or more. Examples of dihydric alcohols include ethylene glycol, propylene glycol, butanediol (e.g., 1,3-butanediol, 1,4-butanediol), and hexanediol (e.g., 1,6-hexanediol). These can be used individually or in combination of two or more. From the viewpoint of versatility, adipic acid-based polyesters are preferred as polyester plasticizers.

[0027] The number-average molecular weight (Mn) of the polyester plasticizer is not particularly limited, but is preferably 500 to 2500, and more preferably 1200 to 2000. A number-average molecular weight of 2500 or less allows for a lower viscosity of the resin composition liquid for the non-foamed layer, further improving processability, especially in the casting process. A number-average molecular weight of 500 or more provides good oil resistance. Here, the number-average molecular weight of the polyester plasticizer is calculated as a polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0028] The viscosity of the polyester plasticizer is not particularly limited, but is preferably 150 to 5000 mPa·s, and more preferably 2000 to 5000 mPa·s. A viscosity of 150 mPa·s or higher results in good oil resistance of the resulting synthetic leather. A viscosity of 5000 mPa·s or lower allows the viscosity of the resin composition liquid for the non-foaming layer to be kept low, further improving processability, especially the processability of the casting method. Here, the viscosity of the polyester plasticizer is the viscosity at 25°C measured using a Brookfield viscometer, and more specifically, it is measured using a BII type viscometer (BHII type, manufactured by Toki Sangyo Co., Ltd., rotor No. 3) at 10 rpm and a liquid temperature of 25°C.

[0029] In the non-foaming layer, the mass ratio (composition ratio as solid content) of phthalate ester plasticizer to polyester plasticizer is (amount of phthalate ester plasticizer):(amount of polyester plasticizer) = 73:27 to 87:13, preferably 77:23 to 83:17. By having a phthalate ester plasticizer composition ratio of 73% by mass or more (i.e., a polyester plasticizer composition ratio of 27% by mass or less), the viscosity of the resin composition liquid for the non-foaming layer can be kept low, resulting in good processability, especially processability by the casting method. By having a phthalate ester plasticizer composition ratio of 87% by mass or less (i.e., a polyester plasticizer composition ratio of 13% by mass or more), good oil resistance can be obtained.

[0030] In this specification, the mass ratio of phthalate ester plasticizers to polyester plasticizers is defined as an integer ratio obtained by rounding to the nearest whole number if the respective proportions of the total of the two plasticizers (with the sum of the two plasticizers being 100) have a fractional part.

[0031] In this specification, "solids" refers to components other than volatile substances such as organic solvents and water, and is also called evaporation residue or non-volatile content. Therefore, liquids that do not evaporate at normal drying temperatures, such as plasticizers, are also included in the solids.

[0032] The plasticizer content in the non-foamed layer (total content of phthalate ester plasticizer and polyester plasticizer) is 60 to 100 parts by mass, preferably 65 to 85 parts by mass, per 100 parts by mass of vinyl chloride resin. A plasticizer content of 60 parts by mass or more provides a flexible texture. Furthermore, the viscosity of the resin composition liquid for the non-foamed layer can be kept low, resulting in good processability, particularly in the casting method. A plasticizer content of 100 parts by mass or less improves strength. Additionally, plasticizer bleeding can be suppressed, improving aesthetic appeal.

[0033] The non-foaming layer may contain conventionally known additives as needed, provided that their physical properties are not impaired. Examples of such additives include plasticizers other than phthalate ester plasticizers and polyester plasticizers, thermoplastic resins other than vinyl chloride resins, thermosetting resins, heat stabilizers, fillers, pigments, amine-resistant agents, flame retardants, conductivity imparters, antistatic agents, ultraviolet absorbers, light stabilizers, antioxidants, pigment dispersants, crosslinking agents, and thickeners, which can be used individually or in combination of two or more.

[0034] Examples of the above-mentioned heat stabilizers include metal soaps such as calcium stearate, magnesium stearate, aluminum stearate, barium stearate, zinc stearate, calcium laurate, barium laurate, and zinc laurate; metal salts such as sodium salts, zinc salts, and barium salts of phenol and / or naphthol; organotin compounds such as dibutyltin dilaurate and dibutyltin dimalate; and phosphite esters such as triphenyl phosphite, tricresyl phosphite, and triisooctyl phosphite. These can be used individually or in combination of two or more. In one embodiment, calcium salts and / or zinc salts of organic acids may be used as the heat stabilizer. The content of the heat stabilizer is not particularly limited and may be, for example, 0.1 to 10 parts by mass or 0.5 to 5 parts by mass per 100 parts by mass of vinyl chloride resin.

[0035] Examples of the above-mentioned amine-resistant agents include perchlorates such as sodium perchlorate and potassium perchlorate. These can be used individually or in combination of two or more. The content of the amine-resistant agent is not particularly limited; for example, it may be 0.05 to 5 parts by mass or 0.1 to 2 parts by mass per 100 parts by mass of vinyl chloride resin.

[0036] The thickness of the non-foamed layer is not particularly limited, but is preferably 100 to 300 μm, and more preferably 130 to 250 μm. A non-foamed layer thickness of 100 μm or more provides good strength. A non-foamed layer thickness of 300 μm or less allows for uniform thickness of the non-foamed layer in the resulting synthetic leather.

[0037] The vinyl chloride resin constituting the foamed layer is a polymer composed of vinyl chloride and / or vinylidene chloride as monomer components. The vinyl chloride resin is not particularly limited, and the same vinyl chloride resin as that used in the non-foamed layer can be used; therefore, a detailed explanation is omitted. The vinyl chloride resin contained in the foamed layer and the vinyl chloride resin contained in the non-foamed layer may be the same or different.

[0038] The resin component constituting the foam layer is preferably mainly composed of a vinyl chloride resin. More specifically, it is preferable that more than 50% by mass of the resin component is vinyl chloride resin, more preferably 80% by mass or more of the resin component is vinyl chloride resin, and it is also possible that 100% by mass of the resin component is vinyl chloride resin.

[0039] The foamed layer contains phthalate ester plasticizers and polyester plasticizers as plasticizers. By using phthalate ester plasticizers and polyester plasticizers in combination, the viscosity of the resin composition liquid for the foamed layer can be kept low. Therefore, the occurrence of foam inclusion and processing streaks can be suppressed, and a uniform film can be formed. Thus, processability, especially processability in casting methods, is improved. Polyester plasticizers have a larger molecular weight compared to other plasticizers. Therefore, by using polyester plasticizers, the diffusion rate of plasticizers into other resin layers is reduced, and the plasticizer is less likely to migrate from the inside to the outside of the foamed layer. Thus, good oil resistance can be obtained.

[0040] The phthalate ester plasticizer and polyester plasticizer in the foamed layer are not particularly limited, and the same phthalate ester plasticizer and polyester plasticizer as those used in the non-foamed layer described above can be used. Therefore, the preference for dialkyl phthalate (C9-C11) as the phthalate ester plasticizer, the preference for adipic acid polyester as the polyester plasticizer, the preference for the number average molecular weight of the polyester plasticizer being 500-2500 (more preferably 1200-2000), and the preference for the viscosity of the polyester plasticizer being 150-5000 mPa·s (more preferably 2000-5000 mPa·s) are the same as those for the non-foamed layer. The phthalate ester plasticizer and polyester plasticizer contained in the foamed layer and the phthalate ester plasticizer and polyester plasticizer contained in the non-foamed layer may be the same or different.

[0041] In the foamed layer, the mass ratio (composition ratio as solid content) of phthalate ester plasticizer to polyester plasticizer is (amount of phthalate ester plasticizer):(amount of polyester plasticizer) = 73:27 to 87:13, preferably 77:23 to 83:17. By having a phthalate ester plasticizer composition ratio of 73% by mass or more (i.e., a polyester plasticizer composition ratio of 27% by mass or less), the viscosity of the resin composition liquid for the foamed layer can be kept low, resulting in good processability, especially processability by the casting method. By having a phthalate ester plasticizer composition ratio of 87% by mass or less (i.e., a polyester plasticizer composition ratio of 13% by mass or more), good oil resistance can be obtained. The mass ratio of phthalate ester plasticizer to polyester plasticizer may be the same or different between the foamed layer and the non-foamed layer.

[0042] The plasticizer content in the foamed layer (total content of phthalate ester plasticizer and polyester plasticizer) is 60 to 100 parts by mass, preferably 65 to 85 parts by mass, per 100 parts by mass of vinyl chloride resin. A plasticizer content of 60 parts by mass or more provides a flexible texture. Furthermore, the viscosity of the resin composition liquid for the foamed layer can be kept low, resulting in good processability, particularly in the casting method. A plasticizer content of 100 parts by mass or less improves strength. Additionally, plasticizer bleeding can be suppressed, improving aesthetic appeal. The plasticizer content may be the same or different between the foamed and non-foamed layers.

[0043] The foamed layer can be formed, for example, by adding a foaming agent to a resin composition liquid for the foamed layer, and can provide a good feel and texture. The foaming agent is not particularly limited, and known foaming agents can be used, but from the viewpoint of foaming properties, it is preferable to use an organic foaming agent. Examples of organic foaming agents include azodicarbonamide (ADCA), 2,2'-azodiisobutyronitrile (AIBN), benzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide, 4,4'-oxybis[benzenesulfonyl hydrazide] (OBSH), and N,N'-dinitrosopentamethylenetetramine (DPT). These can be used individually or in combination of two or more.

[0044] The foaming ratio of the foamed layer is not particularly limited, but is preferably 2 times or less, more preferably 1.1 times or more and 2 times or less, and even more preferably 1.2 times or more and 1.7 times or less. By having a foaming ratio of 2 times or less, independent pores are more easily formed, which can improve abrasion resistance, flexural resistance, and peel strength.

[0045] The thickness of the foam layer is not particularly limited and may be, for example, 150 to 370 μm, but is preferably 190 to 370 μm, and more preferably 200 to 300 μm. A foam layer thickness of 190 μm or more provides a flexible texture. A foam layer thickness of 370 μm or less makes it easy to adjust the diameter of the foam cells.

[0046] The foamed layer may contain conventionally known additives as needed, provided that these additives do not impair its physical properties. Examples of such additives include phthalate ester plasticizers and plasticizers other than polyester plasticizers, thermoplastic resins other than vinyl chloride resins, thermosetting resins, heat stabilizers, fillers, pigments, amine-resistant agents, flame retardants, conductivity imparters, antistatic agents, ultraviolet absorbers, light stabilizers, antioxidants, pigment dispersants, crosslinking agents, and thickeners, which can be used individually or in combination of two or more. Specific examples and their content for heat stabilizers and amine-resistant agents in the foamed layer are the same as those for the non-foamed layer described above.

[0047] In this embodiment, when providing the foamed layer, an adhesive layer may be interposed between the foamed layer and the fibrous substrate, or the foamed layer may be directly laminated onto the fibrous substrate. Interposing an adhesive layer between the fibrous substrate and the foamed layer can improve the adhesion between the fibrous substrate and the foamed layer. The adhesive layer may be a non-foamed resin layer that does not contain air bubbles.

[0048] The resin constituting the adhesive layer is not particularly limited, and any resin commonly used in ordinary polyvinyl chloride leather can be used. Examples include polyurethane resin and polyvinyl chloride-based resin.

[0049] The thickness of the adhesive layer is not particularly limited; for example, it may be 20-200 μm or 50-150 μm.

[0050] In this embodiment, a protective layer may be provided on the non-foamed layer. By providing a protective layer on the non-foamed layer, the physical properties of the resulting synthetic leather, particularly abrasion resistance and oil resistance, can be improved.

[0051] The protective layer preferably contains a polyurethane resin. The polyurethane resin for such a protective layer is not particularly limited, and examples include polyether-based polyurethane resins, polyester-based polyurethane resins, and polycarbonate-based polyurethane resins. These polyurethane resins can be used individually or in combination of two or more. Among these, from the viewpoint of abrasion resistance, polycarbonate-based polyurethane resin is preferred as the polyurethane resin for the protective layer.

[0052] The form of the polyurethane resin for the protective layer is not particularly limited and can be appropriately selected depending on the application. For example, it may be solvent-based or water-based, and may be a one-component or two-component curing type. From the viewpoint of environmental protection, the form of the polyurethane resin is preferably water-based.

[0053] The protective layer resin composition liquid used to form the protective layer may contain optional components as needed, provided that they do not impair the physical properties of the polyurethane resin. Examples of optional components include crosslinking agents, lubricants, leveling agents, thickeners, defoaming agents, light stabilizers, conductivity imparters, antistatic agents, water repellents, oil repellents, antiblocking agents, and antibacterial agents. These can be used individually or in combination of two or more.

[0054] The thickness of the protective layer is not particularly limited, but is preferably 2 to 30 μm, and more preferably 5 to 20 μm. If the thickness is 2 μm or more, abrasion resistance can be improved. If the thickness is 30 μm or less, a flexible texture can be obtained.

[0055] In this embodiment, when providing a protective layer, an undercoat layer may be interposed between the protective layer and the non-foamed layer, or the protective layer may be directly laminated onto the non-foamed layer. By interposing an undercoat layer between the surface layer and the protective layer, the physical properties of the resulting synthetic leather, particularly abrasion resistance, heat yellowing resistance, and oil resistance, can be improved.

[0056] The undercoat layer preferably contains a polyurethane resin. The polyurethane resin for such an undercoat layer is not particularly limited, and examples include polyether-based polyurethane resins, polyester-based polyurethane resins, and polycarbonate-based polyurethane resins. These polyurethane resins can be used individually or in combination of two or more. Among these, polyester-based polyurethane resins are preferred as the polyurethane resin for the undercoat layer from the viewpoint of heat resistance and oil resistance.

[0057] The form of the polyurethane resin for the undercoat layer is not particularly limited and can be appropriately selected depending on the application. For example, it may be solvent-based or water-based, and may be a one-component or two-component curing type. From the viewpoint of environmental protection, it is preferable that the polyurethane resin be water-based.

[0058] The resin composition liquid for the undercoat layer used to form the undercoat layer may contain optional components as needed, provided that these components do not impair the physical properties of the polyurethane resin. Examples of optional components include resins other than polyurethane resin (e.g., acrylic resin), crosslinking agents, leveling agents, defoaming agents, and thickeners. These can be used individually or in combination of two or more.

[0059] The thickness of the undercoat layer is not particularly limited; for example, it may be 1 to 20 μm or 2 to 10 μm.

[0060] Next, a method for manufacturing synthetic leather according to this embodiment will be described. The manufacturing method is not particularly limited, and a manufacturing method similar to that of conventionally known synthetic leather can be employed, such as the calendering method or the casting method. In one embodiment, when using the casting method, the synthetic leather of the embodiment can be manufactured by performing the following steps in order. That is, the manufacturing method is (1) A step of applying a resin composition liquid for a non-foaming layer onto a release substrate to form a non-foaming layer. (2) A step of applying a resin composition liquid for the foamed layer onto the non-foamed layer to form a foamed layer. (3) A process of bonding the foamed layer and the fibrous substrate, (4) Step of peeling off the release material, It includes.

[0061] Various conventionally known methods can be used to apply the resin composition liquid for the non-foaming layer onto a release-type substrate, and are not particularly limited. For example, methods using a knife coater, comma coater, roll coater, or die coater can be used. Among these, coating by a knife coater or comma coater is preferred because it allows for the formation of a uniform thin film layer.

[0062] The release material is not particularly limited and can be any material that has release properties to vinyl chloride resin, or a material that has been treated with a release agent. Examples include release paper, release treated cloth, water-repellent treated cloth, olefin sheets or films made of polyethylene resin or polypropylene resin, fluororesin sheets or films, and plastic films with release paper. The release material may have an uneven surface, and by using such a release material, an uneven surface such as a grain pattern can be formed on the surface of synthetic leather to give it a decorative appearance.

[0063] After applying the non-foaming layer resin composition liquid to the release substrate, heat treatment is performed as necessary. The heat treatment is performed to promote gelation.

[0064] Next, a resin composition liquid for the foamed layer is applied to the non-foamed layer. The method for applying the resin composition liquid for the foamed layer can be the same as the method for applying the resin composition liquid for the non-foamed layer.

[0065] Next, the foamed layer and the fibrous substrate are laminated. Lamination methods include conventionally known methods such as transfer bonding, heat fusion, heat compression bonding, and adhesive bonding. When using an adhesive, the adhesive layer resin composition liquid is applied to the foamed layer before laminating the fibrous substrate. The method for applying the adhesive layer resin composition liquid is the same as the method for applying the non-foamed layer resin composition liquid.

[0066] Next, the release agent is peeled off from the non-foamed layer. By peeling off the release agent, a laminate of the non-foamed layer, the foamed layer, and the fibrous substrate is obtained.

[0067] When forming a protective layer on a non-foaming layer, the protective layer may be formed on the surface of the laminate after peeling off the release substrate as described above. The protective layer may be provided on the non-foaming layer via an undercoat layer, or it may be laminated directly on the non-foaming layer. The method for applying the resin composition liquid for the undercoat layer to the surface of the non-foaming layer is not particularly limited, and the same method as for applying the resin composition liquid for the non-foaming layer can be used.

[0068] To form a protective layer, the same method as the method for applying the resin composition liquid for the non-foaming layer can be used to apply the protective layer to the non-foaming layer or undercoat layer. In addition, methods using equipment such as a spray coater, gravure coater, gravure direct printing press, gravure offset printing press, or screen printing press can also be used.

[0069] Next, heat treatment is performed as necessary. Heat treatment is performed to evaporate the solvent in the protective layer resin composition liquid and dry the resin. In addition, when a crosslinking agent that causes a crosslinking reaction by heat treatment is used, or when a two-component curing type resin is used, heat treatment is performed to accelerate the reaction and form a film with sufficient strength.

[0070] Next, if necessary, a textured pattern, such as a grain pattern, is formed on the non-foamed layer (or the protective layer if one is present). Various conventionally known methods can be used to form the textured pattern after the release substrate has been peeled off, and are not particularly limited. For example, methods using embossing, vacuum embossing, welding, and pin sonic processing can be used.

[0071] Thus, a synthetic leather according to one embodiment is obtained. However, the method for manufacturing the synthetic leather of this embodiment is not limited to the method described above. [Examples]

[0072] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0073] Each evaluation item was assessed according to the following method.

[0074] [Oil resistance] A sample measuring 25 cm wide and 35 cm long was taken. The sample was placed on a glass plate measuring 150 mm wide, 200 mm long, and 3 mm thick, which was laid horizontally. Four pieces of 100% cotton gauze measuring 20 cm wide and 25 cm long ("Bescare Gauze 10m 300-10M" manufactured by Yamato Factory Co., Ltd.) were layered on the surface of the resin layer (non-foaming layer or protective layer) of the test specimen, and 60 mL of oleic acid ("15745-55" manufactured by Nacalai Tesque Co., Ltd.) was dropped onto the 100% cotton gauze. A glass plate measuring 150 mm wide, 200 mm long, and 3 mm thick was placed on top of the 100% cotton gauze. This was left for 72 hours in a forced-air constant-temperature drying oven ("DRM620DD" manufactured by ADVANTEC) adjusted to 80°C. Afterward, the glass plate and 100% cotton gauze were removed, and excess oleic acid was removed by pressing a wiper paper (Kimwipe S-200, manufactured by Nippon Paper Crecia Co., Ltd.) against the area.

[0075] From the center of the oil-resistance test sample obtained, two test pieces measuring 30 mm in width and 120 mm in length were taken, one in the longitudinal direction and the other in the transverse direction. The test pieces taken from the same direction were stacked with the resin layer surface facing inward, and clamped in a Scott kneading test machine (Scott kneading resistance test machine "CV-10N", manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.) with a gripping distance of 30 mm. The gap between the grips was gradually narrowed until the two test pieces separated from each other. After lightly touching the resin layer surface of the test pieces, a load of 9.8 N was applied. The test machine was operated, and a kneading test was performed 2000 times with a load of 9.8 N, a gripping distance of 30 mm, and a kneading stroke of 50 mm. After the test, the condition of the test pieces was observed and judged according to the following criteria. (Judgment criteria) A: No delamination or cracking of the resin layer. B: One or more of the following are present: delamination or cracking of the resin layer.

[0076] [Abrasion resistance] One test specimen measuring 70 mm in width and 300 mm in length was taken from each direction, both vertically and horizontally. A piece of urethane foam measuring 70 mm in width, 300 mm in length, and 10 mm in thickness was attached to the back of each specimen. A 4.5 mm diameter wire was placed in the center of the bottom surface of the urethane foam, and the specimens were fixed to a flat abrasion test machine "T-TYPE" (manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.) and covered with cotton cloth. Friction child An abrasion test was conducted by applying a load of 9.8 N to the friction element so that it reciprocated parallel to the wire. The friction element reciprocated 10,000 times over a distance of 140 mm on the surface of the test piece at a speed of 60 reciprocations / minute. The surface condition of the test piece after the abrasion test was observed and judged according to the following criteria. (Judgment criteria) 5: No change in appearance (no cracks or tears) 4: Slight wear is present, but not noticeable. 3: Items showing obvious signs of wear. 2: Items with exposed fibrous base material 1: Significant exposure of the fibrous base material (tears are visible)

[0077] [Workability] The viscosity of the resin composition liquid for the non-foamed layer and the resin composition liquid for the foamed layer was measured using a BII-type viscometer (BHII type, manufactured by Toki Sangyo Co., Ltd., rotor No. 3, 10 rpm, 23°C) and judged according to the following criteria. A value of A indicates excellent processability. (Judgment criteria) A: 2000~6000 mPa·s B: Less than 2000 mPa·s or more than 6000 mPa·s

[0078] [Texture] The panelists conducted a sensory evaluation and made judgments according to the following criteria. A score of B or higher is considered a passing grade. (Judgment criteria) A: The texture is flexible. B: The texture is slightly rough and hard. C: Rough and hard texture

[0079] [Example 1] <Fiber-based material> The base material is a circular knit fabric (polyester fiber, 580 μm thick, 120 g / m² mass per unit area). 2 I prepared ).

[0080] <Formulation 1: Resin composition liquid for non-foaming layer> • Vinyl chloride resin (polyvinyl chloride, paste resin with an average degree of polymerization of 1300, solid content 100% by mass): 100 parts by mass • Phthalate ester plasticizer (dialkyl phthalate (C9-C11), solids content 100% by mass): 65 parts by mass • Polyester-based plasticizer (adipic acid-based polyester obtained by polycondensation of adipic acid with 1,3-butanediol and 1,4-butanediol, number average molecular weight 1800, viscosity (25℃) 3000 mPa·s, solids content 100% by mass): 10 parts by mass • Ca-Zn-based heat stabilizer (calcium organic acid salt / zinc organic acid salt, solid content 100% by mass): 2 parts by mass Pigment (carbon black, 100% solids by mass): 7 parts by mass • Amine-resistant agent (sodium perchlorate, 100% solids by mass): 0.5 parts by mass Preparation method: After mixing a vinyl chloride resin and a plasticizer, a Ca-Zn heat stabilizer, pigment, and amine inhibitor were added and mixed to obtain a resin composition liquid for the non-foaming layer. The viscosity of the resin composition liquid for the non-foaming layer (at 23°C) was 4000 mPa·s.

[0081] <Formulation 2: Resin composition liquid for foaming layer> • Vinyl chloride resin (polyvinyl chloride, paste resin with an average degree of polymerization of 1300, solid content 100% by mass): 100 parts by mass • Phthalate ester plasticizer (dialkyl phthalate (C9-C11), solids content 100% by mass): 65 parts by mass • Polyester-based plasticizer (adipic acid-based polyester obtained by polycondensation of adipic acid with 1,3-butanediol and 1,4-butanediol, number average molecular weight 1800, viscosity (25℃) 3000 mPa·s, solids content 100% by mass): 10 parts by mass • Ca-Zn-based heat stabilizer (calcium organic acid salt / zinc organic acid salt, solid content 100% by mass): 2 parts by mass Pigment (carbon black, 100% solids by mass): 3 parts by mass • Amine-resistant agent (sodium perchlorate, 100% solids by mass): 1 part by mass • Organic blowing agent (azodicarbonamide, solid content 60% by mass): 1 part by mass Preparation method: After mixing a vinyl chloride resin and a plasticizer, a Ca-Zn heat stabilizer, pigment, amine-resistant agent, and organic blowing agent were added and mixed to obtain a resin composition liquid for the foamed layer. The viscosity of the resin composition liquid for the foamed layer (at 23°C) was 4000 mPa·s.

[0082] <Formulation 3: Resin composition liquid for adhesive layer> • Vinyl chloride resin (hydroxyl group-containing polyvinyl chloride resin obtained by copolymerizing monomers containing hydroxyl groups, average degree of polymerization 1300, solid content 100% by mass): 100 parts by mass • Plasticizer (Dialkyl phthalate (C9-C11), 100% solids): 100 parts by mass • Ca-Zn-based heat stabilizer (calcium organic acid salt / zinc organic acid salt, solid content 100% by mass): 2 parts by mass • Flame retardant (antimony trioxide, 100% solids by mass): 8 parts by mass • Crosslinking agent (isocyanate-based crosslinking agent, 100% solids by mass): 6.5 parts by mass Preparation method: After mixing a vinyl chloride resin and a plasticizer, a Ca-Zn heat stabilizer and a flame retardant were added and mixed, and then a crosslinking agent was added and mixed to obtain a resin composition liquid for the adhesive layer. The viscosity of the resin composition liquid for the adhesive layer was 65,000 mPa·s (BII type viscometer (BHII type), manufactured by Toki Sangyo Co., Ltd., rotor No. 6, 10 rpm, 23℃).

[0083] <Formulation 4: Resin composition liquid for undercoat layer> • Polyurethane resin (aqueous dispersion of polyester-based polyurethane resin, solid content 20.5% by mass): 100 parts by mass • Crosslinking agent (aqueous dispersion of isocyanate-based crosslinking agent, solid content 50% by mass): 2 parts by mass Preparation method: A crosslinking agent was added to polyurethane resin and mixed to obtain a resin composition liquid for the undercoat layer. The viscosity of the resin composition liquid for the undercoat layer was 3000 mPa·s (BII type viscometer (BHII type), manufactured by Toki Sangyo Co., Ltd., rotor No. 3, 10 rpm, 23℃).

[0084] <Formulation 5: Resin composition liquid for protective layer> • Polyurethane resin (aqueous dispersion of polycarbonate-based polyurethane resin, solid content 30% by mass): 100 parts by mass • Crosslinking agent (aqueous dispersion of carbodiimide-based crosslinking agent, solid content 49.5% by mass): 2 parts by mass • Lubricant (aqueous dispersion of silicone resin, 40 parts by mass of solids): 6 parts by mass Preparation method: After mixing a lubricant with polyurethane resin, a crosslinking agent was added and mixed to obtain a resin composition liquid for the protective layer. The viscosity of the resin composition liquid for the protective layer was 1000 mPa·s (BII type viscometer (BHII type), manufactured by Toki Sangyo Co., Ltd., rotor No. 3, 10 rpm, 23℃).

[0085] <Manufacturing of synthetic leather> The non-foaming layer resin composition liquid prepared according to Formulation 1 described above was applied in a sheet form to a flat release paper (product name "VX-12", manufactured by Lintec Corporation) using a comma coater to a coating thickness of 160 μm, and then heat-treated in a dryer at 180°C for 2 minutes and 30 seconds to form a non-foaming layer.

[0086] Next, the resin composition liquid for the foamed layer, prepared according to the above-described formulation 2, was applied in a sheet-like manner to the non-foamed layer formed on the release paper using a comma coater to a coating thickness of 140 μm, and then heat-treated in a dryer at 200°C for 2 minutes and 30 seconds to form a foamed layer.

[0087] Next, the adhesive layer resin composition liquid prepared according to formulation 3 described above was applied to the foamed layer in a sheet-like manner using a knife coater to a coating thickness of 90 μm. Then, the fibrous substrate was placed on top and treated in a dryer at 180°C for 2 minutes and 30 seconds to form the adhesive layer and bond it with the fibrous substrate. After that, the release paper was peeled off to obtain a laminate consisting of a non-foamed layer, a foamed layer, an adhesive layer, and a fibrous substrate.

[0088] Next, the resin composition liquid for the undercoat layer, prepared according to the above-described formulation 4, was applied in a sheet-like manner to the surface of the non-foamed layer after the release paper had been peeled off, using a gravure coater to achieve a coating thickness of 12 μm. The undercoat layer was then formed by heat treatment in a dryer at 130°C for 2 minutes.

[0089] Next, the protective layer resin composition liquid prepared according to the above-described formulation 5 was applied to the surface of the undercoat layer in a sheet form using a gravure coater to a coating thickness of 15 μm, and then heat-treated in a dryer at 130°C for 1 minute to form a protective layer.

[0090] Next, the resulting laminate was preheated at 170°C for 15 seconds using an infrared heater, and then a textured pattern was formed on the surface of the protective layer using a vacuum embossing machine to obtain the synthetic leather of Example 1. The thickness of the non-foamed layer was 160 μm, the foaming ratio of the foamed layer was 1.5 times, and the thickness of the foamed layer was 210 μm.

[0091] The thickness of each resin layer is obtained by observing the vertical cross-section of the synthetic leather with a microscope (Keyence Corporation, Digital HF Microscope VH-8000), measuring the thickness at 10 arbitrary points, and calculating the average value of these measurements.

[0092] The foaming ratio of the foamed layer was determined by applying the foaming layer resin composition liquid onto release paper using a comma coater to a sheet thickness of 140 μm, and then drying it at 200°C for 2 minutes and 30 seconds. The film thickness of the resulting foamed sheet was measured and calculated using the following formula. Foaming ratio (times) = Film thickness of foam sheet / {Coating thickness (140 μm) × Solid content of the foam layer resin composition liquid}

[0093] [Examples 2-14, Comparative Examples 1-6] Synthetic leather was obtained in the same manner as in Example 1, except that the formulations of the resin compositions for each resin layer were changed as shown in Tables 1 to 4. In Tables 1 to 4, "%" for solid content refers to mass percent. Regarding the polyester plasticizers, the viscosity and number-average molecular weight of the adipic acid-based polyesters in Tables 1 to 4 are as described in Tables 1 to 4. In detail, the adipic acid-based polyesters in Tables 1 to 4 were all obtained by polycondensation of adipic acid with 1,3-butanediol and 1,4-butanediol. In Example 7, an adipic acid-based polyester with a number-average molecular weight of 800 and a viscosity (25°C) of 200 mPa·s was used. In Example 8, an adipic acid-based polyester with a number-average molecular weight of 2200 and a viscosity (25°C) of 5000 mPa·s was used. The adipic acid-based polyesters used in the other examples and comparative examples are the same as in Example 1 as described above.

[0094] [Table 1]

[0095] [Table 2]

[0096] [Table 3]

[0097] [Table 4]

[0098] The evaluation results for Examples 1-14 and Comparative Examples 1-6 are shown in Tables 1-4. In Comparative Example 1, the mass ratio of phthalate ester plasticizer to polyester plasticizer in the non-foamed and foamed layers was 93:7, and the oil resistance was poor due to the high amount of phthalate ester plasticizer. In Comparative Examples 3-5, the oil resistance was poor because only phthalate ester plasticizer was contained in the non-foamed and / or foamed layers. In Comparative Example 2, the mass ratio of phthalate ester plasticizer to polyester plasticizer in the non-foamed and foamed layers was 67:33, and although the oil resistance was excellent due to the high content of polyester plasticizer, foam formation occurred and the processability was poor. In Comparative Example 6, the processability was poor due to the low plasticizer content. In contrast, Examples 1-14 showed excellent oil resistance and processability.

[0099] The present invention includes embodiments shown below. [1] Synthetic leather comprising, in this order, a fibrous base material, a foamed layer containing a vinyl chloride resin and a plasticizer, and a non-foamed layer containing a vinyl chloride resin and a plasticizer, wherein in each of the foamed layer and the non-foamed layer, the content of the plasticizer is 60 to 100 parts by mass per 100 parts by mass of the vinyl chloride resin, and the plasticizer comprises a phthalate ester plasticizer and a polyester plasticizer, and further, the mass ratio of the phthalate ester plasticizer to the polyester plasticizer is 73:27 to 87:13 (preferably 77:23 to 83:17). [2] The synthetic leather according to [1], wherein the number average molecular weight of the polyester plasticizer in the foamed layer and the non-foamed layer is 500 to 2500 (preferably 1200 to 2000). [3] The synthetic leather according to [1] or [2], wherein the viscosity of the polyester plasticizer in the foamed layer and the non-foamed layer at 25°C is 150 to 5000 mPa·s (preferably 2000 to 5000 mPa·s). [4] The synthetic leather according to any one of [1] to [3], wherein the polyester plasticizer in the foamed layer and the non-foamed layer is at least one selected from the group consisting of adipic acid-based polyester, sebaciate-based polyester, and phthalic acid-based polyester, preferably an adipic acid-based polyester plasticizer. [5] The synthetic leather according to any one of [1] to [4], wherein the phthalate ester plasticizer in the foamed layer and the non-foamed layer is at least one selected from the group consisting of dibutyl phthalate, dioctyl phthalate, dinonyl phthalate, diisononyl phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, benzyl butyl phthalate, nonylundecyl phthalate, and dialkyl phthalate (C9 to C11), preferably dialkyl phthalate (C9 to C11). [6] The synthetic leather according to any one of [1] to [5], wherein the thickness of the non-foamed layer is 100 to 300 μm (preferably 130 to 250 μm). [7] The synthetic leather according to any one of [1] to [6], wherein the foamed layer and the non-foamed layer each further contain a heat stabilizer (preferably an organic acid calcium salt and / or organic acid zinc salt), and preferably the content of the heat stabilizer is 0.1 to 10 parts by mass (preferably 0.5 to 5 parts by mass) per 100 parts by mass of the vinyl chloride resin. [8] The synthetic leather according to any one of [1] to [7], wherein the foamed layer and the non-foamed layer each further contain an amine-resistant agent (preferably a perchlorate), and preferably the content of the amine-resistant agent is 0.05 to 5 parts by mass (preferably 0.1 to 2 parts by mass) per 100 parts by mass of the vinyl chloride resin. [9] The synthetic leather according to any one of [1] to [8], wherein the foamed layer is formed by adding a foaming agent (preferably an organic foaming agent) to a foamed layer resin composition liquid.

[10] The synthetic leather according to any one of [1] to [9], wherein the foaming ratio of the foamed layer is 2 times or less (preferably 1.1 times or more and 2 times or less, more preferably 1.2 times or more and 1.7 times or less).

[11] The synthetic leather according to any one of [1] to

[10] , wherein the thickness of the foam layer is 150 to 370 μm (preferably 190 to 370 μm, more preferably 200 to 300 μm).

[12] The synthetic leather according to any one of [1] to

[11] , further comprising an adhesive layer containing a polyurethane resin and / or a vinyl chloride resin between the fibrous base material and the foam layer.

[13] The synthetic leather according to any one of [1] to

[12] , further comprising a protective layer containing a polyurethane resin (preferably a polycarbonate-based polyurethane resin) on the non-foamed layer.

[14] The synthetic leather according to

[13] , wherein the thickness of the protective layer is 2 to 30 μm (preferably 5 to 20 μm).

[15] The synthetic leather according to

[13] or

[14] , further comprising an undercoat layer containing a polyurethane resin (preferably a polyester-based polyurethane resin) between the non-foaming layer and the protective layer.

[16] The synthetic leather according to any one of [1] to

[15] , wherein the non-foaming layer is a resin layer formed by applying a resin composition liquid for a non-foaming layer onto a release substrate, and the foamed layer is a resin layer formed by applying a resin composition liquid for a foamed layer onto the non-foaming layer formed on the release substrate, and the resin composition liquid for the non-foaming layer and the resin composition liquid for the foamed layer each contain a vinyl chloride resin and a plasticizer containing a phthalate ester plasticizer and a polyester plasticizer in a mass ratio of 73:27 to 87:13, and the content of the plasticizer per 100 parts by mass of the vinyl chloride resin is 60 to 100 parts by mass.

[17] Synthetic leather according to any one of items [1] to

[16] , wherein the surface surface is provided with an uneven pattern (preferably a grained pattern).

[0100] Furthermore, the various numerical ranges described in this specification can be any combination of their upper and lower limits, and all such combinations are described herein as preferred numerical ranges. In addition, unless otherwise specified, the numerical range description "X~Y" means X or greater and Y or less. [Explanation of symbols]

[0101] 1, 10, 100…Synthetic leather, 2…Fibrous base material, 3…Foam layer, 4…Non-foam layer, 5…Adhesive layer, 6…Protective layer, 7…Undercoat layer

Claims

1. A synthetic leather comprising, in this order, a fibrous base material, a foamed layer containing a vinyl chloride resin and a plasticizer, and a non-foamed layer containing a vinyl chloride resin and a plasticizer, In each of the foamed layer and the non-foamed layer, the content of the plasticizer is 60 to 100 parts by mass per 100 parts by mass of the vinyl chloride resin, and the plasticizer comprises a phthalate ester plasticizer and a polyester plasticizer, and the mass ratio of the phthalate ester plasticizer to the polyester plasticizer is 73:27 to 87:

13. Synthetic leather wherein the phthalate ester plasticizer in the foamed layer and the non-foamed layer is dialkyl phthalate (C9-C11) and / or diundecyl phthalate.

2. The synthetic leather according to claim 1, wherein the number average molecular weight of the polyester plasticizer in the foamed layer and the non-foamed layer is 500 to 2500.

3. The synthetic leather according to claim 1 or 2, wherein the viscosity of the polyester plasticizer in the foamed layer and the non-foamed layer at 25°C is 150 to 5000 mPa·s.

4. The synthetic leather according to any one of claims 1 to 3, wherein the polyester plasticizer in the foamed layer and the non-foamed layer is an adipic acid-based polyester plasticizer.

5. The synthetic leather according to any one of claims 1 to 4, further comprising an adhesive layer containing a polyurethane resin and / or a vinyl chloride resin between the fibrous base material and the foam layer.

6. The synthetic leather according to any one of claims 1 to 5, further comprising a protective layer containing a polyurethane resin on the non-foamed layer.

7. The synthetic leather according to claim 6, further comprising an undercoat layer containing polyurethane resin between the non-foaming layer and the protective layer.

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