Synthetic leather and synthetic leather manufacturing method

Abstract

To provide a synthetic leather using reinforcing fibers and having a natural leather texture, and also to provide a method for manufacturing the synthetic leather.SOLUTION: A synthetic leather of the invention includes a fiber base material layer including a needle-punched felt, and a resin layer that includes resin and is disposed on the fiber base material layer. The needle-punched felt includes reinforcing fibers. A method for manufacturing the synthetic leather of the invention includes a step to form the resin layer on the fiber base material by applying a resin material onto the fiber base material including the needle-punched felt. The needle-punched felt includes the reinforcing fibers.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an artificial leather and a method for producing the artificial leather. [Background technology]

[0002] Synthetic leather is a substitute for natural leather that has a similar texture to natural leather and is obtained by forming a resin layer on a fiber substrate. Such synthetic leather is widely used in transportation equipment such as automobiles, interiors of houses and furniture, clothing, etc.

[0003] As the fiber base material constituting synthetic leather, generally used is a woven or nonwoven fabric using flexible fibers such as polyester fibers or polyethylene fibers (for example, Patent Document 1).

[0004] Incidentally, fiber reinforced plastics (FRP), which use fibers such as glass fibers as reinforcing materials, are lightweight, high-strength, and highly elastic materials, and are widely used in components for small ships, automobiles, railway cars, etc. Also, carbon fiber reinforced plastics (CFRP), which use carbon fibers as reinforcing materials, have been developed and are used in components for aircraft, automobiles, sporting goods, etc. On the other hand, in recent years, the amount of waste fiber reinforced plastics has been increasing, and disposal of the waste has become a problem. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-96704 A Summary of the Invention [Problem to be solved by the invention]

[0006] Reinforcing fibers such as glass fibers and carbon fibers are generally provided as filaments and therefore used as woven fabrics, and therefore when the reinforcing fibers are used in synthetic leather, the synthetic leather does not easily exhibit the texture of natural leather.

[0007] On the other hand, if it were possible to produce synthetic leather that has the texture of natural leather and is also sufficiently thick and flexible, using reinforcing fibers, it would be possible to reuse the fiber-reinforced plastics that are currently causing problems.

[0008] Therefore, an object of the present invention is to provide an artificial leather using reinforcing fibers and having the texture of natural leather, and a method for producing said artificial leather. [Means for solving the problem]

[0009] As a result of intensive research aimed at achieving the above-mentioned object, the inventors discovered that by creating needle-punched felt using reinforcing fibers and using this as a fiber base material, synthetic leather having the texture of natural leather can be produced, thereby arriving at the present invention.

[0010] The gist of the present invention is as follows. [1] A fiber substrate layer including a needle punched felt; A resin layer including a resin and disposed on the fiber base material layer; The needle punched felt is a synthetic leather comprising reinforcing fibers. [2] The synthetic leather described in [1], wherein the reinforcing fibers include one or more types selected from the group consisting of glass fibers, carbon fibers, and basalt fibers. [3] The synthetic leather described in [1], wherein the reinforcing fibers include recycled reinforcing fibers. [4] The synthetic leather according to [1], wherein the needle punched felt further contains natural fibers and / or chemical fibers. [5] The synthetic leather described in [1], wherein the content of the reinforcing fiber in the needle punched felt is 50% by mass or more and 100% by mass or less. [6] The weight of the needle punched felt is 30 g / m2 More than 500g / m 2 The synthetic leather described in [1] below. [7] The synthetic leather described in [1], having an average thickness of 0.50 mm or more and 3.0 mm or less. [8] The needle punched felt has a density of 10 threads / cm 2 More than 500 pieces / cm 2 The synthetic leather described in [1] is needle punched with the following penetration count. [9] The synthetic leather according to [1], wherein the needle-punched felt has a warp / weft ratio based on the tensile strength as specified in JIS L 1913:2010, a general nonwoven fabric testing method, of 30:1 to 1:30.

[10] The synthetic leather according to [1], further comprising an oil and / or a sizing agent adhered to at least a portion of the surface of the reinforcing fibers contained in the needle-punched felt.

[11] A method for producing a resin film comprising the steps of: applying a resin material onto a fiber substrate including a needle-punched felt to form a resin layer on the fiber substrate; The needle punched felt contains reinforcing fibers. Effect of the Invention

[0011] As described above, according to the present invention, it is possible to provide synthetic leather using reinforcing fibers and having the texture of natural leather, and a method for producing said synthetic leather. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an enlarged cross-sectional view showing a synthetic leather according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a photographic image of the surface of the synthetic leather according to the embodiment. [Diagram 3] FIG. 3 is a photographic image for evaluating the flexibility of the synthetic leather according to the embodiment. [Figure 4] FIG. 4 is a photographic image of a product processed using the synthetic leather of the embodiment. [Diagram 5]FIG. 5 is a photographic image of a product processed using the synthetic leather of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the synthetic leather and the method for producing the synthetic leather according to the present invention will be described in detail with reference to the drawings.

[0014] <1.Synthetic leather> First, a synthetic leather according to a preferred embodiment of the present invention will be described. Fig. 1 is an enlarged cross-sectional view showing the synthetic leather according to one embodiment of the present invention.

[0015] In addition, in the Household Products Quality Labeling Act, a product using woven fabric as the substrate is called synthetic leather, and a product using special nonwoven fabric as the substrate is called artificial leather. However, in this specification, a product that imitates leather and has a resin layer supported on a fiber substrate layer is called synthetic leather, regardless of whether or not a special nonwoven fabric is used as the substrate (fiber substrate layer 10). In other words, synthetic leather in this specification is a concept that includes both synthetic leather and artificial leather in the Household Products Quality Labeling Act. And, when synthetic leather in this specification is manufactured using a special nonwoven fabric as the substrate (fiber substrate layer 10), the synthetic leather can be artificial leather in the Household Products Quality Labeling Act.

[0016] The synthetic leather 1 of this embodiment has a fiber base material layer 10, a resin layer 20 arranged on the fiber base material layer 10, and a coating layer 30 arranged on the opposite side of the resin layer 20 to the fiber base material layer 10.

[0017] The fiber base material layer 10 is a supporting base material for the synthetic leather 1, and ensures physical properties such as tensile strength and tear strength of the synthetic leather 1. In this embodiment, the fiber base material layer 10 includes a needle-punched felt 11 and a resin 13 filled in voids in the needle-punched felt 11.

[0018] The needle-punched felt 11 is configured to include reinforcing fibers 15. The reinforcing fibers 15 are fibers that are generally used as reinforcing fibers for fiber-reinforced resin materials. The reinforcing fibers 15 have high strength and contribute to improving the tensile strength and tear strength of the fiber base material layer 10 including the needle-punched felt 11, and thus the synthetic leather 1. On the other hand, the reinforcing fibers 15 are generally provided as filaments and used as a woven cloth. For this reason, synthetic leather using such a woven cloth has a texture that is significantly different from that of natural leather.

[0019] In addition, since the fiber base material layer 10 has the needle-punched felt 11 containing the reinforcing fiber 15, appropriate unevenness is created on the surface of the resin layer 20, improving the texture of the synthetic leather 1 and making it possible to make the texture of the synthetic leather 1 closer to the texture of natural leather.

[0020] The reinforcing fibers 15 contained in the needle punched felt 11 are not particularly limited, but examples thereof include carbon fibers, glass fibers, aramid fibers, Kevlar fibers, Dyneema fibers, basalt fibers, and boron fibers, and one of these may be used alone or two or more may be used in combination. Examples of carbon fibers include PAN (polyacrylonitrile)-based carbon fibers, pitch-based carbon fibers, and rayon-based carbon fibers, and one or both may be used.

[0021] Among the above, the reinforcing fibers 15 contained in the needle-punched felt 11 preferably contain one or more types selected from the group consisting of glass fibers, carbon fibers, and basalt fibers, and more preferably glass fibers and / or carbon fibers.

[0022] As a result, synthetic leather with texture can be produced from reinforcing fibers that have been used mainly for high-rigidity plastic reinforcement applications. In particular, since glass fibers are translucent, light scattering occurs at the interface between the glass fibers and the resin 13, which can impart a unique texture to the synthetic leather 1.

[0023] In addition, the reinforcing fiber 15 preferably contains recycled reinforcing fiber. Fiber-reinforced resin materials are used in many applications, but the disposal of waste materials after use is a problem. In particular, carbon fiber-reinforced resin materials and glass fiber-reinforced resin materials are used in large quantities, and it is preferable to effectively utilize these recycled reinforcing fibers from the viewpoint of reusing resources.

[0024] Here, in this embodiment, the recycled reinforcing fibers include not only reinforcing fibers derived from fiber-reinforced resin materials contained in products that are discarded due to reasons such as use, but also, for example, fiber-reinforced resin materials that are generated during the manufacture of products and are no longer needed, prepregs thereof, their scraps and parts, and unused products that are no longer needed. In addition, the recycled reinforcing fibers also include reinforcing fibers that are no longer needed because they were not used in the manufacture of fiber-reinforced resin materials. Specific examples of recycled carbon fibers include the recycled reinforcing fibers of the above-mentioned reinforcing fibers, such as recycled carbon fibers, recycled glass fibers, recycled aramid fibers, recycled Kevlar fibers, recycled Dyneema fibers, recycled basalt fibers, and recycled boron fibers.

[0025] The content of the recycled reinforcing fibers in the reinforcing fibers 15 is not particularly limited, but can be, for example, 50% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more. In particular, the reinforcing fibers 15 are more preferably substantially made of recycled reinforcing fibers, and even more preferably made of recycled reinforcing fibers.

[0026] The content of the reinforcing fibers 15 in the needle-punched felt 11 is not particularly limited, but is, for example, 50% by mass to 100% by mass, preferably, for example, 80% by mass to 100% by mass, and more preferably, 90% by mass to 100% by mass. This allows the flexibility of the fiber base material layer 10 including the needle-punched felt 11, and thus the synthetic leather 1, to be sufficient, while also allowing the tensile strength and tear strength of the synthetic leather 1 to be sufficient. Furthermore, a sufficient amount of the reinforcing fibers 15 can be included in the needle-punched felt 11, and when recycled reinforcing fibers are used, resources can be used more effectively.

[0027] The average fiber length of the reinforcing fibers 15 in the needle-punched felt 11 is not particularly limited, but is, for example, 20 mm or more and 200 mm or less, preferably 30 mm or more and 100 mm or less, and more preferably 30 mm or more and 70 mm or less.

[0028] The needle-punched felt 11 may further contain natural fibers and / or chemical fibers. When the needle-punched felt 11 contains such fibers, the processability and flexibility of the synthetic leather 1 can be easily adjusted within an appropriate range.

[0029] Examples of natural fibers include, but are not limited to, animal fibers such as wool, cashmere, mohair, llama hair, camel hair, rabbit hair, horse hair, and silk; and plant fibers such as cotton, kapok, hemp, kenaf, flax, Indian hemp, Manila hemp, and coconut. One of these fibers may be used alone, or two or more may be used in combination.

[0030] Examples of chemical fibers include synthetic fibers, semi-synthetic fibers, and regenerated fibers. Examples of synthetic fibers include acrylic fibers such as acrylic fibers and modacrylic fibers, polyester fibers such as polyethylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polyether ester fibers, polyolefin fibers such as polyethylene and polypropylene, polyacrylate fibers, polyvinyl chloride fibers, nylon fibers such as nylon 6 and nylon 66, polyamide fibers, polyimide fibers, aramid fibers, polyetherimide fibers, polyphenylene sulfide fibers, polyurethane fibers, polyvinyl alcohol fibers, ethylene vinyl alcohol fibers, and polyarylate fibers. These may be used alone or in combination of two or more.

[0031] Examples of the semi-synthetic fibers include Promix fibers and acetate fibers. Examples of regenerated fibers include regenerated cellulose fibers such as viscose rayon, cupra, and acetate.

[0032] Furthermore, the total content of natural fibers and chemical fibers in the needle punched felt 11 is not particularly limited, but is, for example, 0% by mass or more and 50% by mass or less, preferably, for example, 0% by mass or more and 20% by mass or less, more preferably, 0% by mass or more and 10% by mass or less, and even more preferably, 0% by mass or more and 5.0% by mass or less.

[0033] The weight of the needle punched felt 11 is not particularly limited, but is, for example, 30 g / m 2 More than 500g / m 2 Less than 50 g / m 2 More than 300g / m 2 Less than 80 g / m 2 More than 150g / m 2 This allows the synthetic leather 1 to have sufficient flexibility and processability while allowing a relatively large amount of reinforcing fibers to be used.

[0034] The needle punch felt 11 has a density of, for example, 10 needles / cm 2 More than 500 pieces / cm 2 Less than 30 / cm, preferably 30 / cm 2 More than 350 pieces / cm 2 Less than or equal to 50 fibers / cm, more preferably 2 More than 200 pieces / cm 2 The needle punching is performed with the following penetration number. This allows the fibers in the needle punched felt 11 to be appropriately entangled, and as a result, appropriate unevenness is generated in the needle punched felt 11, resulting in more natural unevenness on the surface of the resin layer 20. As a result, it is possible to make the texture of the synthetic leather 1 even closer to the texture of natural leather.

[0035] The warp / weft ratio of the needle-punched felt 11 based on the tensile strength defined in the general nonwoven fabric test method of JIS L 1913:2010 is not particularly limited, but is, for example, 30:1 to 1:30. The warp / weft ratio of the needle-punched felt 11 can represent the degree of orientation of the fibers in the needle-punched felt 11. When the warp / weft ratio of the needle-punched felt 11 is within the above range, the orientation of the fibers in the needle-punched felt 11 is relatively small, and the unevenness generated on the surface of the resin layer 20 can be made more natural. As a result, the texture of the synthetic leather 1 can be made even closer to the texture of natural leather. The warp / weft ratio of the needle-punched felt 11 is preferably 30:1 to 1:30, more preferably 10:1 to 1:10.

[0036] With respect to the direction of the length-width ratio, when the needle-punched felt 11 is viewed in plan, the direction connecting two points that are the greatest distance apart from each other among any points that form the outline is defined as the length, and the direction perpendicular to the length is defined as the width. Depending on the needle-punched felt 11, it may be difficult to perform a tensile strength test due to the needle-punched felt 11 being very thin or for other reasons. In this case, for example, a sheet may be made by stacking and adhering a plurality of needle-punched felts 11 so that they face the same direction, and a tensile strength test may be performed on this sheet. The length-width ratio of the sheet obtained based on the results of the tensile strength test of the sheet may be defined as the length-width ratio of the needle-punched felt 11.

[0037] The needle-punched felt 11 may also contain an oil and / or a sizing agent attached to at least a portion of the surface of the reinforcing fibers 15 contained in the needle-punched felt 11. This ensures that the reinforcing fibers 15 are dispersed in the needle-punched felt 11, and makes the unevenness on the surface of the resin layer 20 appear more natural. As a result, the texture of the synthetic leather 1 can be made to be closer to the texture of natural leather.

[0038] The oil prevents adhesion between fibers and prevents adhesion of the reinforcing fibers 15 and, if present, other fibers in the needle-punched felt 11. Such oils are not particularly limited, and examples thereof include aromatic ester-based oils, alkyl ester-based oils, ester-based oils such as ester compounds, polyamide-based oils, silicone oils, urethane-based oils, phosphate-based oils, boric acid-based oils, (poly)oxyalkylene derivative-based oils, and the like, and one of these may be used alone or two or more may be used in combination. Examples of silicone oils include amino-modified silicones, epoxy-modified silicones, and ether-modified silicones.

[0039] Examples of (poly)oxyalkylene derivative oils include compounds in which alkylene oxides are added to alcohols or carboxylic acids, and ether / ester compounds in which alkylene oxides are added to ester compounds of carboxylic acids and polyhydric alcohols. The alcohols or carboxylic acids may be linear or branched aliphatic alcohols or carboxylic acids, or aromatic alcohols or carboxylic acids. They may also be saturated alcohols or carboxylic acids, or unsaturated alcohols or carboxylic acids. They may also be monohydric, dihydric or higher alcohols or carboxylic acids.

[0040] Examples of (poly)oxyalkylene derivative oils include an ethylene oxide adduct of butanol, an ethylene oxide adduct of glycerin, an ethylene oxide adduct of oleic acid, an ethylene oxide adduct of laurylamine, an ethylene oxide adduct of 3,5,5-trimethyl-1-hexanol, an ethylene oxide adduct of stearyl alcohol, an ethylene oxide adduct of lauric acid, an ethylene oxide adduct of diethylenetriamine dioleylamide, an ethylene oxide adduct of diethyleneamine monolaurylamide, an ethylene oxide adduct of sorbitan monooleate, an ethylene oxide adduct of hydrogenated castor oil, and an ethylene oxide-propylene oxide adduct of glycerin.

[0041] Examples of the ester compound include oleic acid esters of alcohols having 12 to 13 carbon atoms, sorbitan monooleate, and hydrogenated castor oil.

[0042] The content of the oil in the needle punched felt 11 is, for example, 0.050% by mass or more and 10% by mass or less, and preferably 0.10% by mass or more and 5.0% by mass or less, relative to the reinforcing fibers 15.

[0043] The sizing agent bundles the fibers in the needle punched felt 11 together, and also provides the reinforcing fibers 15 with affinity for the resin 13 in the fiber base material layer 10. The sizing agent is not particularly limited, but examples thereof include epoxy-based sizing agents, urethane-based sizing agents, acrylic-based sizing agents, vinyl ester-based sizing agents, isocyanate-based sizing agents, titanate-based sizing agents, polyamide-based sizing agents, maleic anhydride-modified polyolefin-based sizing agents, silane-based sizing agents, olefin-based sizing agents, styrene-based sizing agents, and polyester-based sizing agents, and one of these may be used alone or two or more may be used in combination.

[0044] Examples of epoxy-based sizing agents include epoxy-based resins such as bisphenol A-type epoxy resins. Examples of vinyl ester-based sizing agents include vinyl ester-based resins such as bisphenol A-type vinyl ester resins, novolac-type vinyl ester resins, and brominated vinyl ester resins. Examples of urethane-based sizing agents include aromatic urethane-based sizing agents and aliphatic urethane-based sizing agents. Each of the above-mentioned sizing agents may contain a urethane-modified resin.

[0045] The content of the sizing agent in the needle punched felt 11 is, for example, 0.05% by mass to 20% by mass, and preferably 0.10% by mass to 10% by mass, relative to the reinforcing fibers 15.

[0046] In addition, in FIG. 1, an embodiment in which the fiber base material layer 10 has only needle-punched felt 11 as the base material is described, but the present invention is not limited to the embodiment shown in the figure, and the fiber base material layer 10 may contain other fiber base materials.

[0047] Such fiber substrates include woven and nonwoven fabrics made of natural fibers, chemical fibers, or a mixture of these fibers. As for the natural and chemical fibers, one of the natural and chemical fibers usable for the needle punched felt 11 described above can be used alone or in combination of two or more. Further, the present invention is not limited to the embodiment shown in the drawings, and the fiber base material layer 10 may include a plurality of needle-punched felts 11.

[0048] Furthermore, when the fiber base material layer 10 contains a fiber base material other than the needle-punched felt 11, the needle-punched felt 11 may be located in any position, but may be arranged, for example, in a position of the fiber base material layer 10 closest to the resin layer 20.

[0049] Moreover, the fiber substrate layer 10 usually contains a resin 13. The resin 13 is impregnated into each fiber substrate, such as the needle-punched felt 11, in the fiber substrate layer 10, and functions as a matrix resin present between the fibers. This bonds the fibers contained in the needle-punched felt 11, etc. in the fiber substrate layer 10 together, and when the fiber substrate layer 10 contains multiple fiber substrates, bonds the fiber substrates together. Furthermore, the resin 13 present on the surface of the fiber substrate layer 10 bonds the fiber substrate layer 10 and the resin layer 20 together.

[0050] The resin 13 contained in the fiber substrate layer 10 is not particularly limited, and may be one type or a combination of two or more types of resins that can be used in the resin layer 20 described below. The resin 13 contained in the fiber substrate layer 10 may be the same as or different from the resin contained in the resin layer 20.

[0051] However, it is preferable that at least one type of resin in the fiber base material layer 10 is the same as at least one type of resin contained in the resin layer 20. This allows stronger adhesion between the fiber base material layer 10 and the resin layer 20. It is particularly preferable that the resin in the fiber base material layer 10 is the same as the resin contained in the resin layer 20.

[0052] The elongation of the resin 13 contained in the fiber base material layer 10 in a tensile test measured based on JIS K 7161:2014 is not particularly limited, but is, for example, 20% or more, preferably 30% or more, and more preferably 50% or more, which can further improve the processability and flexibility of the synthetic leather 1.

[0053] The resin layer 20 is disposed on the fiber base material layer 10 and contains a resin. The resin layer 20 is a layer that expresses the leather texture of the synthetic leather 1. That is, the surface 21 of the resin layer 20 has unevenness that reflects the unevenness originating from the fiber base material layer 10. In addition, the leather texture of the synthetic leather 1 is expressed in the resin layer 20 in combination with the texture and color of the resin that constitutes the resin layer 20.

[0054] The resin constituting the resin layer 20 is not particularly limited, and examples thereof include urea-based resins, urethane acrylate-based resins, epoxy resins, saturated or unsaturated polyurethane-based resins, polyvinylidene chloride (PVDC) resins, polyvinyl chloride-based resins such as polyvinyl chloride (PVC), polyester-based resins such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and polybutylene terephthalate (PBT), polyolefin-based resins such as polyethylene (PE) and polypropylene (PP), nylon (polyamide)-based resins, acetate-based resins, polyvinyl alcohol-based resins (vinylon resins), polystyrene-based resins, polycarbonate-based resins, acrylic resins, silicone resins, butadiene resins, and the like. One of these can be used alone, or two or more can be used in combination.

[0055] Moreover, the resin constituting the resin layer 20 preferably has viscoelastic properties in the usage environment, for example, a temperature environment of −20° C. to 90° C., that is, is preferably an elastomer.

[0056] The glass transition temperature (Tg) of the resin constituting the resin layer 20 is not particularly limited, but is, for example, −25° C. or lower, more preferably −30° C. or lower, even more preferably −35° C. or lower, and even more preferably −40° C. or lower.

[0057] The elongation of the resin constituting the resin layer 20 in a tensile test measured based on JIS K 7161:2014 is not particularly limited, but is, for example, 20% or more, preferably 30% or more, and more preferably 50% or more, which can further improve the processability and flexibility of the synthetic leather 1.

[0058] Furthermore, the resin layer 20 may contain, as necessary, optional components such as conventionally known additives, for example, flame retardants, conductivity imparting agents, water repellents, defoamers, pigment dispersants, hydrolysis inhibitors, crosslinking agents, colorants (pigments, dyes), matting agents, smoothing agents, surfactants, fillers, leveling agents, thickeners, etc., either alone or in combination of two or more, within the scope that does not impair the physical properties of the resin layer 20.

[0059] The coating layer 30 is a resin layer disposed on the opposite side of the resin layer 20 to the fiber base material layer 10. The coating layer 30 is provided mainly to impart texture such as gloss.

[0060] The resin constituting the coating layer 30 is not particularly limited, and the resins usable in the resin layer 20 described above can be used alone or in combination of two or more. Similarly to the resin layer 20, the coating layer 30 can use the above-mentioned additives alone or in combination of two or more as appropriate. The coating layer 30 may be omitted.

[0061] The average thickness of the synthetic leather 1 described above is not particularly limited, but is, for example, 0.10 mm to 5.0 mm, preferably 0.50 mm to 3.0 mm, and more preferably 0.50 mm to 2.0 mm. Reinforcing fibers such as carbon fibers generally have high rigidity, and when the synthetic leather is relatively thick, the rigidity of the synthetic leather itself may become excessively large. However, in this embodiment, by including reinforcing fibers 15 in the needle punched felt 11, the synthetic leather 1 can have appropriate flexibility and processability even when the synthetic leather is relatively thick.

[0062] As described above, the synthetic leather 1 according to this embodiment contains the needle-punched felt 11 in the fiber base material layer 10, and the needle-punched felt 11 further contains the reinforcing fibers 15. Therefore, the surface 21 of the resin layer 20 adjacent to the fiber base material layer 10 has appropriate unevenness resulting from the needle-punched felt 11, improving the texture of the synthetic leather 1 and making it possible to make the texture of the synthetic leather 1 closer to that of natural leather.

[0063] In addition, in this embodiment, by using the reinforcing fibers 15 as a constituent material of the needle-punched felt 11, the orientation of the reinforcing fibers 15 in the needle-punched felt 11 is randomized, thereby preventing an excessive increase in the bending rigidity of the synthetic leather 1. As a result, the synthetic leather 1 has sufficient flexibility and processability as a synthetic leather.

[0064] <2. Manufacturing method of synthetic leather> First, a method for producing a synthetic leather according to a preferred embodiment of the present invention will be described. The method for producing synthetic leather according to the present invention includes a step of forming a resin layer on a fiber substrate including a needle-punched felt by applying a resin material thereon (a resin layer forming step), and the needle-punched felt includes reinforcing fibers. The method for producing synthetic leather according to the present embodiment also includes a preparation step of preparing a fiber substrate prior to the resin layer forming step.

[0065] (2.1. Preparation process) In this step, a fiber base material including a needle-punched felt 11 is prepared. The needle-punched felt 11 can be obtained, for example, by forming a fiber web of fibers containing reinforcing fibers 15 and then subjecting the fiber web to a needle-punching process. This will be described in detail below.

[0066] First, a fiber web containing reinforcing fibers 15 is prepared. The fiber web is obtained by mixing the fibers for producing the needle punched felt 11 to obtain a fiber mass, and defibrating the mass. The mixed fibers can be defibrated using various defibrators. Usually, an opener defibrator is used for rough defibration, and the fiber mass after rough defibration is subjected to secondary defibration using a carding machine to obtain a sliver as the fiber web.

[0067] Here, as the opener fiberizer, various known opener fiberizers such as mechanical type, jet type, etc. can be used. Furthermore, as the carding machine, various carding machines such as a wire carding machine, a flat carding machine, a tandem carding machine, a combination carding machine, and a roller carding machine can be used.

[0068] In addition, a plurality of the obtained slivers may be laminated to form a fiber web so that the basis weight of the fiber web matches the basis weight of the needle punched felt 11 to be produced. In this case, the method of laminating the slivers may be any of a unidirectional web, a cross lay web, and a criss cross web. In addition, when a plurality of slivers are laminated, the fiber composition of each sliver used for lamination may be the same or different.

[0069] Next, the fiber web is subjected to needle punching to obtain a needle punched felt 11. In the needle punching, the fibers in the fiber web are entangled with each other.

[0070] In this case, the fiber web may have, for example, 10 fibers / cm 2 More than 500 pieces / cm 2 Less than 30 / cm, preferably 30 / cm 2 More than 350 pieces / cm 2 Less than or equal to 50 fibers / cm, more preferably 2 More than 200 pieces / cm 2 It is preferable to perform needle punching with the following penetration number. This allows the fibers in the needle punched felt 11 to be appropriately entangled, and creates appropriate unevenness on the needle punched felt 11.

[0071] The needle punching may be performed on both sides of the fiber web, or only on one side. However, it is preferable to perform the needle punching on the side of the fiber web that faces the resin layer 20 of the fiber base material layer 10. This creates appropriate unevenness in the needle punched felt 11 on the resin layer 20 side, improving the texture of the synthetic leather 1.

[0072] When the needle-punched felt 11 contains an oil and / or a sizing agent, a predetermined amount of the oil and / or the sizing agent may be applied to the fiber mass by immersing the fiber mass in a treatment liquid containing the oil and / or the sizing agent, or by spraying the treatment liquid, etc. After applying a predetermined amount of the oil and / or the sizing agent to the fiber mass, unnecessary solvent and excess oil and sizing agent may be removed by dehydration through squeezing, air drying or heat drying.

[0073] The application of the oil and / or sizing agent may be performed on the fiber agglomerate or fiber web after defibration, and on the needle-punched felt 11, but is preferably performed on the fiber agglomerate before defibration. This makes defibration and the subsequent formation of the needle-punched felt 11 easier.

[0074] The obtained needle-punched felt 11 itself may be used as the fiber base material, but the fiber base material may be formed by further laminating other fiber base materials, such as woven fabrics and nonwoven fabrics made of natural fibers, chemical fibers, or a mixture of these fibers, in addition to the needle-punched felt 11. The fiber base material may be formed by stacking a plurality of needle-punched felts 11, or a plurality of needle-punched felts 11 may be combined with another fiber base material to form a fiber base material.

[0075] When a plurality of fibrous substrates are used, the fibers in the fibrous web may be bonded to each other in order to bond the stacked plurality of fibrous substrates together or to adjust the thickness of a single fibrous web.

[0076] (2.2. Resin layer formation process) In this step, a resin material is applied onto a fiber substrate including a needle-punched felt 11 to form a resin layer 20 on the fiber substrate. As a result, the resin layer 20 and a fiber substrate as a fiber substrate layer 10 are obtained.

[0077] The method of applying the resin material onto the fiber substrate is not particularly limited, and the resin material can be applied onto the fiber substrate by, for example, coating or spraying a liquid resin material, or immersing the fiber substrate in the liquid resin material. When applying a liquid resin material onto the fiber substrate, at least a part of the resin material is impregnated into the fiber substrate and becomes the resin 13 in the fiber substrate layer 10.

[0078] The liquid resin material includes the resin and / or its precursor constituting the resin layer 20 described above, and optionally a liquid medium that dissolves and / or disperses the resin and / or its precursor. Examples of the liquid medium include water and various known organic solvents, and one type may be used alone or two or more types may be used in combination. The liquid resin material may optionally include one type of known additive such as a surfactant, either alone or in combination.

[0079] After the resin material is applied to the fiber substrate, a heat treatment may be performed as necessary. If the resin material contains a precursor of a thermosetting resin, the precursor is cured to form the resin layer 20. If the resin material contains a liquid medium, the liquid medium is removed and the resin material is solidified to form the resin layer 20.

[0080] The heating temperature during the heat treatment is not particularly limited, and can be, for example, from 15 (room temperature)° C. to 200° C., and preferably from 25° C. to 120° C. The heating time is also not particularly limited, and can be, for example, from 5 minutes to 4,320 minutes, and preferably from 60 minutes to 360 minutes.

[0081] In addition to heating, the fiber substrate to which the resin material has been applied may be pressed during the heat treatment, which allows the resin material to sufficiently permeate the fiber substrate and improves the adhesion between the resin layer 20 and the fiber substrate layer 10.

[0082] Alternatively, when the resin material contains thermoplasticity, the resin material can be applied to the fiber substrate by placing a sheet-like solid resin material on the fiber substrate and thermocompression bonding. Even when a sheet-like solid resin material is placed on the fiber substrate and thermocompression bonding is performed, the resin material softened during thermocompression bonding is impregnated into the fiber substrate and becomes the resin 13 in the fiber substrate layer 10. The heating conditions during thermocompression bonding are the same as those for the heating treatment using the liquid resin material described above.

[0083] (2.3. Coating layer forming process) The method for producing the synthetic leather according to this embodiment also includes a coat layer forming step of forming the coat layer 30 on the resin layer 20. The coat layer 30 can be formed by the same method as the resin layer 20.

[0084] Alternatively, after the resin material for the resin layer 20 is applied onto the fiber substrate, the resin material for the coating layer 30 may be applied onto the resin material for the resin layer 20 and then the heat treatment may be performed. In this case, the number of times of the heat treatment can be reduced, and the resin layer 20 and the coating layer 30 can be formed simultaneously. When the coating layer 30 is not formed, this step may be omitted.

[0085] In this manner, the synthetic leather 1 according to the present embodiment can be manufactured.

[0086] The present invention has been described in detail above based on a preferred embodiment, but the present invention is not limited to this, and each component can be replaced with any component that can perform a similar function, or any component can be added. EXAMPLES

[0087] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0088] (Example) 1. Manufacturing of synthetic leather 1.1. Preparation process First, recycled carbon fibers (fiber length 50 mm) were collected by a solvent method from a carbon fiber reinforced resin material containing carbon fibers (T800SC, manufactured by Toray Industries, Inc.) as reinforcing fibers. Next, the fiber mass of the obtained recycled carbon fibers was immersed in an emulsion containing an oil (ester-based oil, effective concentration 3.0 mass%), and then dehydrated and dried. The amount of oil adhering to the recycled carbon fibers was 1.0 mass%.

[0089] Next, the recycled carbon fiber mass was roughly crushed with an opener. The roughly crushed fiber mass was fed into a wire carding machine to obtain a fiber web (sliver) with a width of 30 cm.

[0090] This fiber web is fed into a needle punch machine and subjected to needle punching treatment, so that the carbon fibers are entangled in the z direction (thickness direction) to produce a fiber web with a width of 30 cm, a length of 70 cm, and a basis weight of 150 g / m 2 Thus, needle punched felt of the above formula was obtained.

[0091] Here, in the needle punching process, the number of needles (needle density) is 66 / cm 2 The fiber web was then needle punched on both sides. The warp / weft ratio of the obtained needle-punched felt based on the tensile strength specified in the general nonwoven fabric testing method of JIS L 1913:2010 was 3:1.

[0092] 1.2. Resin layer forming process and coating layer forming process After mixing the two-component curing unsaturated polyester resin, the needle-punched felt was impregnated with the unsaturated polyester resin by hand coating. The elongation of this unsaturated polyester resin in a tensile test measured according to JIS K 7161:2014 was approximately 200%.

[0093] Furthermore, the surface of the needle punched felt impregnated with the unsaturated polyester resin was covered with a polycarbonate film as a coating layer. Next, this needle punched felt was sandwiched between two stainless steel plates and heated at 100° C. for 2 hours while being pressed, to obtain the synthetic leather according to the example.

[0094] Fig. 2 is a photographic image of the surface of the synthetic leather according to the embodiment, and Fig. 3 is a photographic image for evaluating the flexibility of the synthetic leather according to the embodiment. As shown in Fig. 2, the synthetic leather according to the embodiment had a texture sufficiently close to that of natural leather. Also, as shown in Fig. 3, the synthetic leather according to the embodiment could be easily curved by hand, and had sufficient flexibility.

[0095] Figures 4 and 5 are photographs of products processed using the synthetic leather of the embodiment. As shown in Figures 4 and 5, the synthetic leather of the embodiment can be easily sewn, cut, punched, etc., and can be processed into products with a satisfactory texture. [Explanation of symbols]

[0096] 1 Synthetic leather 10 Fiber base material layer 11 Needle punch felt 13 Resin 15 Reinforcing Fibers 20 Resin layer 30 Coating Layer

Claims

1. A fiber substrate layer including a needle punched felt; A resin layer including a resin and disposed on the fiber base material layer; The needle punched felt is a synthetic leather comprising reinforcing fibers.

2. The synthetic leather according to claim 1 , wherein the reinforcing fibers include at least one selected from the group consisting of glass fibers, carbon fibers, and basalt fibers.

3. The synthetic leather of claim 1 , wherein the reinforcing fibers include recycled reinforcing fibers.

4. The synthetic leather according to claim 1 , wherein the needle-punched felt further comprises natural fibers and / or chemical fibers.

5. 2. The synthetic leather according to claim 1, wherein the content of the reinforcing fibers in the needle punched felt is 50% by mass or more and 100% by mass or less.

6. The weight of the needle punched felt is 30 g / m ２ More than 500g / m ２ 2. The synthetic leather according to claim 1, wherein:

7. 2. The synthetic leather according to claim 1, having an average thickness of 0.50 mm or more and 3.0 mm or less.

8. The needle punched felt has a density of 10 needles / cm ２ More than 500 pieces / cm ２ 2. The synthetic leather according to claim 1, which is needle punched at the following penetration number:

9. The synthetic leather according to claim 1, wherein the needle-punched felt has a warp / weft ratio based on the tensile strength defined in JIS L 1913:2010 General Nonwoven Fabric Testing Method of 30:1 to 1:

30.

10. 2. The synthetic leather according to claim 1, further comprising an oil and / or a sizing agent attached to at least a portion of the surface of the reinforcing fibers contained in the needle-punched felt.

11. The method includes a step of applying a resin material onto a fiber substrate including a needle-punched felt to form a resin layer on the fiber substrate, The needle punched felt contains reinforcing fibers.

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