Artificial leather and manufacturing method thereof, and clothing, miscellaneous goods

Abstract

To provide an artificial leather having elegant surface appearance on both surfaces and high stretchability regardless of high thickness.SOLUTION: An artificial leather comprises: an entangled fiber assembly including a nonwoven fabric formed of ultra fine fibers having average single fiber diameter of 0.01 μm or more and 10.00 μm or less and a woven or knitted fabric formed of crimped fibers; and elastomer. The artificial leather has nap on both surfaces. The entangled fiber assembly is formed by laminating the nonwoven fabric, the woven or knitted fabric, and the nonwoven fabric in this order. The nonwoven fabrics have thickness of 0.4 mm or more and 2.0 mm or less, respectively. Cross section of the artificial leather satisfies following formula 1: 1.2≤R1 / R2≤2.0...(formula 1), where R1, R2 are area percentage (%) of the elastomer at a part closest to a nap side of a region that is equally divided into three parts in a thickness direction after eliminating the nap part of the nonwoven fabric part, and area percentage (%) of elastomer at a part closest to the woven or knitted fabric side, respectively.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an artificial leather comprising a fiber-entangled body containing a nonwoven fabric made of ultrafine fibers as a constituent element and a polymeric elastomer. [Background technology]

[0002] Artificial leathers with a natural leather look, which are made of a fiber-entangled structure containing a nonwoven fabric mainly made of ultrafine fibers as a component and a polymeric elastomer, have superior characteristics compared to natural leather in terms of high durability and uniformity of quality, and there are a wide variety of types of artificial leathers to suit different applications, such as suede-like artificial leathers with a brushed surface and grain-like artificial leathers with a polymeric elastomer applied to the surface layer.

[0003] Suede-like artificial leather is highly regarded for its high-quality, uniform texture and luster due to its raised surface, and is used in a wide range of applications, including automotive interior materials, furniture, miscellaneous goods, and clothing. When artificial leather is used as the surface of clothing, hats, gloves, etc., excellent stretchability and flexibility are required from the viewpoints of comfort when worn and formability.

[0004] To achieve a good feel, artificial leather is often used on both the front and back sides, but when using artificial leather intended for single-sided use, the backs of the pieces must be glued together by sewing or using glue, which poses potential problems such as increased processing costs and reduced stretchability. Therefore, from the perspective of reducing processing costs and preventing a decrease in stretchability, there is a demand for stretchable artificial leather intended for double-sided use that has good nap quality on both sides. Furthermore, since no glueing is required, there is a demand for artificial leather that is thick enough in one piece and has a rich texture.

[0005] Various stretchable artificial leathers intended for double-sided napping have been proposed. For example, Patent Document 1 proposes a method for producing an artificial leather composed of a fiber entanglement and polyurethane, in which a fiber web having a specific hot water shrinkage rate and a woven or knitted fabric composed of polyurethane are laminated and entangled together, the resulting fiber entanglement is shrunk in hot water in both the longitudinal and transverse directions, and the fiber entanglement is impregnated with a polymeric elastomer. This method is described as providing an artificial leather that has a luxurious appearance, stretchability in both the longitudinal and transverse directions, and excellent fit and retention. Patent Document 2 also proposes an artificial leather comprising a woven or knitted fabric, a fiber entanglement of ultrafine fibers with a single fiber fineness of 1.1 dtex or less, and a polymeric elastomer, in which at least one fiber component of the woven or knitted fabric is a latent crimp-producing polyester fiber composed of polytrimethylene terephthalate. This method is described as providing an artificial leather with a soft texture, excellent flexibility, stretchability, and stretch-back properties. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-154340 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-239178 Summary of the Invention [Problem to be solved by the invention]

[0007] In the technology disclosed in Patent Document 1, the woven or knitted fabric inside the fiber-entangled structure is significantly shrunk, causing the entire fiber-entangled structure to shrink in both the longitudinal and transverse directions, and the structure contains a polymeric elastomer that maintains this state, resulting in an artificial leather that is resistant to structural deformation even with repeated extension and deformation. However, with such artificial leather, there is a problem in that as the thickness of the artificial leather increases, the strength of the woven or knitted fabric to sufficiently shrink the fiber-entangled structure becomes insufficient, making it impossible to obtain an artificial leather that is sufficiently thick while maintaining stretchability.

[0008] In the technology disclosed in Patent Document 2, the fibers constituting the woven or knitted fabric inside the artificial leather are crimped, creating a spring-like effect and imparting stretchability to the entire artificial leather. However, in such artificial leather, the woven or knitted fabric is firmly fixed by ultrafine fibers and a polymeric elastomer, limiting the degree of freedom of the woven or knitted fabric. As the thickness of the artificial leather increases, stretchability decreases, making it impossible to obtain stretchable artificial leather with a substantial thickness.

[0009] The present invention has been made in view of the above circumstances, and its object is to provide an artificial leather that has an elegant surface appearance on both surfaces and is highly stretchable despite its thickness. [Means for solving the problem]

[0010] As a result of extensive investigations conducted by the present inventors to achieve the above object, it has become possible to obtain an artificial leather that has an elegant surface appearance on both surfaces and is thick yet highly stretchable, by adjusting the ratio of the thickness of each nonwoven fabric in an entangled fiber structure in an artificial leather, i.e., a nonwoven fabric made of ultrafine fibers, a woven or knitted fabric, and a nonwoven fabric made of ultrafine fibers, in that order, to the area percentage of the polymeric elastomer present on the napped portion side of the nonwoven fabric and on the woven or knitted fabric side in the cross section of the artificial leather, within a specific range. The present invention was completed based on these findings, and the following inventions are provided by the present invention. [1] A nonwoven fabric composed of ultrafine fibers having an average single fiber diameter of 0.01 μm or more and 10.00 μm or less; A woven or knitted fabric composed of crimped fibers; A fiber-entangled body comprising: A polymeric elastomer; An artificial leather having both surfaces with raised nap, The fiber-entangled body is formed by laminating the nonwoven fabric, the woven or knitted fabric, and the nonwoven fabric in this order, The nonwoven fabric has a thickness of 0.4 mm or more and 2.0 mm or less, and satisfies the following formula 1 in the cross section of the artificial leather. 1.2≦R1 / R2≦2.0 (Formula 1) where: R1: The area ratio (%) of the polymer elastomer in the most napped part of the cross section of the artificial leather, divided into three equal parts in the thickness direction, excluding the napped part of the nonwoven fabric part R2: The area ratio (%) of the polymeric elastomer in the part closest to the woven or knitted fabric in the cross section of the artificial leather, excluding the napped part from the nonwoven fabric part, divided into three equal parts in the thickness direction. [2] The artificial leather according to [1], wherein the area ratio of the polymeric elastomer in the entire cross section of the artificial leather is 0.1% or more and 10.0% or less. [3] The artificial leather according to [1] or [2], wherein the area ratio of the polymeric elastomer measured from the surface of the artificial leather is 0.01% or more and 3.00% or less on both surfaces. [4] The artificial leather according to any one of [1] to [3], wherein the average nap length of at least one surface of the artificial leather is 200 μm or more and 600 μm or less. [5] A nonwoven fabric composed of ultrafine fibers having an average single fiber diameter of 0.01 μm or more and 10.00 μm or less; A woven or knitted fabric composed of crimped fibers; A fiber-entangled body comprising: A polymeric elastomer; A method for producing artificial leather having raised nap on both surfaces, a step of entangling a woven or knitted fabric on one side of nonwoven fabric α made of ultrafine fiber-developing fibers to form an entangled sheet; A step of forming a nonwoven fabric β made of ultrafine fiber development type fibers; a step of laminating the entangled sheet and the nonwoven fabric β so that the woven or knitted fabric is sandwiched between the nonwoven fabric α and the nonwoven fabric β, and entangled and integrated by needle punching to form a precursor sheet; applying a water-soluble resin to the precursor sheet to form a water-soluble resin-coated sheet; a step of providing a polymeric elastomer to the water-soluble resin-coated sheet to form a polymeric elastomer-coated sheet; generating the ultrafine fibers from the ultrafine fiber-producing fibers in the polymeric elastomer-attached sheet to form an ultrafine fiber sheet; grinding both surfaces of the ultrafine fiber sheet to form a raised sheet; and The entangled sheet satisfies the following formula 2: In the step of forming the precursor sheet, The nonwoven fabric β before the entanglement and integration satisfies the following formula 3, The entangled sheet and the nonwoven fabric β before being entangled and integrated satisfy the following formula 4: The entanglement and integration satisfies the following formula 5: Artificial leather manufacturing method 0.50≦V A1 / V A2 ≦0.80 (Formula 2) 0.50≦V β1 / V β2 ≦0.80 (Equation 3) 0.30≦V β3 / V A ≦0.80 (Formula 4) 0.30≦D A / D β ≦0.70 (Equation 5) where: V A1 Apparent density (g / cm) of the nonwoven fabric α in the region containing the woven or knitted fabric on the surface of the two regions obtained by dividing the cross section of the entangled sheet into two equal parts in the thickness direction 3 ) V A2 Apparent density (g / cm) of nonwoven fabric α in the region containing nonwoven fabric α on the surface of the two regions obtained by dividing the cross section of the entangled sheet into two equal parts in the thickness direction 3 ) V β1 Apparent density (g / cm) of the nonwoven fabric β in the cross section of the nonwoven fabric β before the entanglement and integration in the area divided equally in the thickness direction into two parts that are the woven / knitted fabric side 3 ) V β2Apparent density (g / cm) of the nonwoven fabric β in a region that is not on the woven / knitted fabric side in a region that is equally divided in the thickness direction in the cross section of the nonwoven fabric β before the entanglement and integration 3 ) V A : Apparent density (g / cm) of the entangled sheet before entanglement and integration 3 ) V β3 : Apparent density (g / cm) of the nonwoven fabric β before the entanglement and integration 3 ) D A : Needle punch density (numbers / cm) punched from the entangled sheet side 3 ) D β : Needle punch density (counts / cm) punched from the β side of the nonwoven fabric 3 ) [6] V A and V β3 However, both are 0.01g / cm 3 More than 0.30g / cm 3 The method for producing an artificial leather according to [5] above, which is as follows: [7] A method for producing an artificial leather according to [5] or [6], wherein in the step of forming the water-soluble resin-coated sheet, the water-soluble resin is added in an amount of 25% by mass or more and 50% by mass or less relative to the mass of the precursor sheet. [8] A method for producing an artificial leather according to any one of [5] to [7], wherein in the step of forming the polymeric elastomer-attached sheet, the polymeric elastomer is added in an amount of 4% by mass or more and 20% by mass or less relative to the mass of the water-soluble resin-attached sheet. [9] Clothing comprising the artificial leather according to any one of [1] to [4].

[10] Miscellaneous goods including the artificial leather according to any one of [1] to [4]. [Effects of the Invention]

[0011] According to the present invention, it is possible to obtain artificial leather that has an elegant surface appearance on both surfaces and that is thick yet highly stretchable. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional conceptual diagram illustrating a method for measuring the average nap length of an artificial leather according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional conceptual diagram illustrating a method for measuring the thickness of a nonwoven fabric in an artificial leather according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The artificial leather of the present invention has a fiber-entangled body including a nonwoven fabric made of ultrafine fibers having an average single fiber diameter of 0.01 μm or more and 10.00 μm or less, and a woven or knitted fabric made of crimped fibers, and a polymeric elastomer, and both surfaces of the artificial leather have raised nap; The fiber-entangled body is formed by laminating the nonwoven fabric, the woven or knitted fabric, and the nonwoven fabric in this order, The nonwoven fabric has a thickness of 0.4 mm or more and 2.0 mm or less, and satisfies the following formula 1 in the cross section of the artificial leather. 1.2≦R1 / R2≦2.0 (Formula 1) where: R1 is the area ratio (%) of the polymer elastomer in the most napped part of the cross section of the artificial leather, in the region excluding the napped part from the nonwoven fabric part, divided into three equal parts in the thickness direction, R2 is the area ratio (%) of the polymer elastomer in the part closest to the woven or knitted fabric in the cross section of the artificial leather, which is obtained by dividing the area of ​​the nonwoven fabric excluding the napped part into three equal parts in the thickness direction. These components will be described in detail below, but the present invention is not limited to the scope described below as long as it does not deviate from the gist of the invention.

[0014] [Fiber entanglement] The fiber-entangled body of the artificial leather of the present invention includes a nonwoven fabric made of ultrafine fibers having an average single fiber diameter of 0.01 μm or more and 10.00 μm or less.

[0015] The ultrafine fibers used in nonwoven fabrics are preferably composed primarily of melt-spinnable thermoplastic resins, such as polyesters (e.g., polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, and polylactic acid); polyamides (e.g., polyamide 6, polyamide 66, and polyamide 12); polyolefins (e.g., acrylic, polyethylene, and polypropylene); polyphenylene sulfide (PPS); and thermoplastic cellulose. Among these, polyester-based resins are preferred from the viewpoints of strength, dimensional stability, and light resistance. In the present invention, the term "major component" refers to a component whose content accounts for 50% or more by mass of the constituent elements. For example, "the main component of the ultrafine fibers is polyethylene terephthalate" means that 50% or more by mass of the components of the ultrafine fibers is polyethylene terephthalate.

[0016] Examples of the polyester resin include polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polylactic acid, as well as polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, and polyethylene-1,2-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylate. Among these, polyethylene terephthalate, which is the most widely used, or a polyester copolymer containing primarily ethylene terephthalate units is preferably used. In the present invention, "polyester copolymer containing primarily ethylene terephthalate units" refers to a polyester copolymer containing 80 mol% or more of ethylene terephthalate units, whose copolymerization component is isophthalic acid or bisphenol A.

[0017] Furthermore, the polyester-based resin may be a single polyester or a blend of two or more different polyesters. When a blend of two or more different polyesters is used, the difference in intrinsic viscosity (IV value) of the polyesters used is preferably 0.50 or less, and more preferably 0.30 or less, from the viewpoint of compatibility between the two or more components.

[0018] In the present invention, the intrinsic viscosity is calculated by the following method. (1) Dissolve 0.8 g of sample polymer in 10 mL of orthochlorophenol. (2) Relative viscosity η measured using an Ostwald viscometer at 25°C r Calculate using the formula below and round off to three decimal places. η r =η / η0=(t×d) / (t0×d0) Intrinsic viscosity (IV value) = 0.0242η r +0.2634 where η is the viscosity of the polymer solution, η0 is the viscosity of orthochlorophenol, t is the drop time of the solution (seconds), and d is the density of the solution (g / cm 3 ), t0 is the fall time of orthochlorophenol (seconds), and d0 is the density of orthochlorophenol (g / cm 3 ) respectively.

[0019] From the viewpoint of processing operability, the cross-sectional shape of the ultrafine fibers is preferably round (a cross-sectional shape that is a perfect circle); however, other shapes can also be used depending on the desired properties, such as oval, capsule-like, polygonal (including shapes with rounded corners) shapes, fan-shaped, cross-shaped, hollow, Y-shaped, T-shaped, and U-shaped cross-sectional shapes.

[0020] The average single fiber diameter of the ultrafine fibers is 0.01 μm or more and 10.00 μm or less. By making the average single fiber diameter of the ultrafine fibers 0.01 μm or more, preferably 1.00 μm or more, excellent effects are achieved in color development after dyeing, light fastness and friction fastness, and stability during spinning. On the other hand, by making the average single fiber diameter of the ultrafine fibers 10.00 μm or less, preferably 5.00 μm or less, artificial leather with a smooth feel and fine surface quality can be obtained.

[0021] In the present invention, the average single fiber diameter of ultrafine fibers is calculated by taking an SEM image of the cross section of the artificial leather using a scanning electron microscope (SEM, for example, Model VHX-D500 / D510 manufactured by Keyence Corporation), randomly selecting 10 circular or nearly circular elliptical ultrafine fibers, measuring the single fiber diameter, calculating the arithmetic average of the 10 fibers, and rounding off to two decimal places. However, when ultrafine fibers with a modified cross section are used, the diameter of the single fiber is determined by first measuring the cross-sectional area of ​​the single fiber and calculating the diameter when the cross section is considered to be circular.

[0022] To the resin forming the ultrafine fibers, various additives may be added according to various purposes, within the scope of not impairing the object of the present invention, such as black pigments described below, chromatic fine particle oxide pigments such as "iron oxyhydroxide and cobalt aluminate," inorganic particles such as titanium oxide particles, lubricants, heat stabilizers, ultraviolet absorbers, conductive agents, heat storage agents, antibacterial agents, etc.

[0023] The artificial leather of the present invention contains the nonwoven fabric made of the ultrafine fibers as a constituent element.

[0024] By forming the fabric into a nonwoven fabric, it is possible to obtain a uniform and elegant appearance and texture when the surface is raised.

[0025] Nonwoven fabrics come in two forms: long-fiber nonwoven fabrics made primarily of filaments, and short-fiber nonwoven fabrics made primarily of fibers 100 mm or less. When short-fiber nonwoven fabrics are used, more fibers can be oriented in the thickness direction of the artificial leather than when long-fiber nonwoven fabrics are used, and by raising the fabric, the surface of the artificial leather can be made to have a high density and a good feel to the touch.

[0026] When using a short-fiber nonwoven fabric, the fiber length of the ultrafine fibers is preferably 25 mm or more and 95 mm or less. By setting the fiber length to 95 mm or less, more preferably 85 mm or less, and even more preferably 75 mm or less, the artificial leather will have an excellent texture and a dense, smooth surface. On the other hand, by setting the fiber length to 25 mm or more, more preferably 35 mm or more, and even more preferably 40 mm or more, the artificial leather will have excellent abrasion resistance.

[0027] Furthermore, in the artificial leather of the present invention, for the purpose of imparting stretchability, strength, and shape stability, a woven fabric may be inserted into the nonwoven fabric and integrated to form a fiber-entangled body. In this way, the fiber-entangled body is formed by laminating the nonwoven fabric, the woven or knitted fabric, and the nonwoven fabric in this order, and an artificial leather having an elegant surface appearance on both surfaces can be obtained.

[0028] [Woven and knitted fabrics] (1) Crimped fiber The woven or knitted fabric contained in the artificial leather of the present invention is made of crimped fibers.

[0029] The crimped fiber is preferably made of two or more polyethylene terephthalate resins having different intrinsic viscosities. Furthermore, the crimped fiber is preferably a conjugated fiber in which two or more polyethylene terephthalate polymers having different intrinsic viscosities are bonded side-by-side along the fiber length, or a yarn made of an eccentric sheath-core conjugated fiber in which two or more polyethylene terephthalate polymers having different intrinsic viscosities form an eccentric sheath-core structure. Internal strain occurs in such yarns due to stress concentration on the high-viscosity side. This internal strain within the conjugated fiber causes crimps in the yarn, which in turn imparts stretchability to the artificial leather.

[0030] Furthermore, the woven or knitted fabric can be entangled with ultrafine fiber-developing fibers (described later) to form a fiber-entangled structure, and then heat-shrunk to further crimp the crimped fibers, thereby imparting stretchability to the artificial leather. By heat-shrinking, the crimped fibers constituting the woven or knitted fabric have a hollow structure (hereinafter referred to as a hollow structure). This hollow structure of the yarn imparts stretchability to the sheet, and further imparts volume and voids to the sheet, thereby imparting a soft texture, moderate resilience, and a satisfying feel to the hand. Furthermore, the strong shrinkage force of the woven or knitted fabric increases the fiber density on the surface of the sheet, imparting a dense, luxurious appearance and a pleasant feel to the touch.

[0031] The difference in intrinsic viscosity between the two or more polyethylene terephthalate resins constituting the crimped fiber is preferably 0.2 or more. Furthermore, the intrinsic viscosity of the polyethylene terephthalate resin of the present invention is preferably 0.5 or more and 2.0 or less for the main component on the high viscosity side. By setting the intrinsic viscosity to 0.5 or more, it becomes possible to produce fibers that combine sufficient strength and elongation. Furthermore, the upper limit of the intrinsic viscosity is preferably 2.0 or less in terms of ease of molding by melt extrusion, production costs, and molecular weight reduction due to molecular chain scission caused by heat or shear force during the process. On the other hand, by setting the intrinsic viscosity of the main component on the low viscosity side to 0.3 or more and 1.0 or less, stable spinning becomes possible.

[0032] The intrinsic viscosity referred to in the present invention is the intrinsic viscosity (IV value) measured by the following method, in which a sample is dissolved in orthochlorophenol (hereinafter abbreviated as OCP) and measured at a temperature of 25°C. (1) Dissolve 0.8 g of sample polymer in 10 mL of OCP. (2) The solution was cooled to 25°C and the relative viscosity (η r ) is calculated using the following formula to calculate the intrinsic viscosity (IV value) η r =η / η0=(t×d) / (t0×d0) Intrinsic viscosity (IV value) = 0.0242η r +0.2634 where: η: viscosity of polymer solution η0: Viscosity of OCP t: Time it takes for the solution to fall (seconds) d: Density of the solution (g / cm 3 ) t0: OCP fall time (seconds) d0: Density of OCP (g / cm 3 ) is.

[0033] The difference in intrinsic viscosity can be adjusted to a desired value by appropriately adjusting the polymerization time, temperature, amount of catalyst, and copolymerization components of the polyethylene terephthalate resin.

[0034] The polyethylene terephthalate resin according to the present invention is composed mainly of a copolymer structure of terephthalic acid or a derivative thereof and ethylene glycol or a derivative thereof, where "main component" means that the resin accounts for more than 50% by weight of the total weight.

[0035] The polyethylene terephthalate resin according to the present invention may contain other copolymerizable components capable of forming ester bonds. Examples of copolymerizable compounds include, but are not limited to, dicarboxylic acids such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid, sebacic acid, and sodium 5-isophthalate, and diols such as ethylene glycol, diethylene glycol, butanediol, neopentyl glycol, cyclohexanedimethanol, polyethylene glycol, and polypropylene glycol. Furthermore, titanium dioxide as a matting agent, silica or alumina fine particles as a lubricant, hindered phenol derivatives as antioxidants, and coloring pigments may be added as needed.

[0036] In the present invention, the composite fiber constituting the woven or knitted fabric is preferably made of a polyethylene terephthalate resin, because this resin has favorable properties for producing the artificial leather of the present invention. Since composite fibers using a polyethylene terephthalate resin exhibit crimp at relatively high temperatures, unintended crimping can be prevented, and an artificial leather with excellent stretchability can be easily obtained.

[0037] The cross-sectional shape of the composite fiber is not particularly limited and may be a round cross section, a triangular cross section, a multilobal cross section, a flat cross section, an X-shaped cross section, or any other modified cross section. From the viewpoint of a balance between crimp expression and texture, a semicircular side-by-side cross section with a round cross section is preferably used, from the viewpoint of a balance between light weight, heat retention, and resilience, a hollow side-by-side cross section is preferably used, and from the viewpoint of a dry texture, a triangular cross section side-by-side cross section is preferably used.

[0038] The composite fiber is, for example, a filament, a spun yarn, an innovative spun yarn, a mixed composite yarn of a filament and a spun yarn, etc. Among them, a filament is more preferable, and a multifilament is more preferable, because when, for example, a needle punching method is used in the process of integrating the woven or knitted fabric with the nonwoven fabric, there is little shedding of fluff and the occurrence of defects exposed on the surface can be suppressed.

[0039] Furthermore, it is also a preferred embodiment that the conjugate fiber is a hard-twisted yarn. In this case, the twist number is preferably 1000 T / m or more and 4500 T / m or less. By setting the twist number to preferably 1000 T / m or more, more preferably 1500 T / m or more, the conjugate fibers constituting the woven or knitted fabric are able to maintain a solid rod-like structure with increased strength. In particular, when the conjugate fiber is in the form of a multifilament, the constituent single fibers are less likely to get caught on the barbs of the needles during needle punching, which prevents a decrease in the physical properties of the product and the exposure of the single fibers to the surface of the product. Furthermore, by setting the twist number to preferably 4500 T / m or less, more preferably 4000 T / m or less, not only is single fiber breakage suppressed, but the conjugate fibers constituting the woven or knitted fabric do not become too stiff, resulting in a softer texture.

[0040] The diameter of the single fiber constituting the woven or knitted fabric is preferably in the range of 0.3 μm to 50 μm. By making the single fiber diameter preferably 0.3 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more, breakage of the threads constituting the woven or knitted fabric during needle punching is suppressed, thereby improving the shape stability of the product as an artificial leather, eliminating the need for densification in anticipation of damage to the woven or knitted fabric, and resulting in an artificial leather with greater flexibility. Furthermore, by making the single fiber diameter preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 20 μm or less, an artificial leather with greater flexibility can be obtained. The single fiber diameter can be measured in the same manner as the average single fiber diameter of ultrafine fibers.

[0041] (2) Woven and knitted fabrics The woven or knitted fabric according to the present invention has the crimped fibers as a constituent element. Here, "having crimped fibers as a constituent element" does not necessarily mean that all of the fibers constituting the woven or knitted fabric are the crimped fibers, but rather means that other fibers may be included as constituent elements as long as the effects of the present invention are not impaired. Examples of the latter embodiment include an embodiment in which the crimped fibers are used only in the weft or only in the warp. This makes it possible to impart stretchability to the artificial leather only in a specific direction.

[0042] In the present invention, the term "woven or knitted fabric" refers collectively to woven fabrics and knitted fabrics, and their weaves are not particularly limited. For example, in the case of woven fabrics, plain weave, twill weave, satin weave, etc. are listed, with plain weave being preferred from the viewpoint of cost. In addition, in the case of knitted fabrics, circular knit, tricot, raschel, etc. are listed.

[0043] Furthermore, when a woven fabric is used in the present invention, the weave density of the woven fabric is preferably adjusted so that both the warp and weft threads in the artificial leather are 40 threads / 2.54 cm or more and 200 threads / 2.54 cm or less. Having a weave density of 40 threads / 2.54 cm or more for the woven fabric inside the artificial leather allows for an artificial leather with excellent shape stability. On the other hand, having a weave density of 200 threads / 2.54 cm or less for the woven / knitted fabric inside the artificial leather allows for a softer texture.

[0044] [Polymeric elastomer] The substrate of the artificial leather of the present invention further comprises a polymeric elastomer in addition to the fiber-entangled structure comprising the nonwoven fabric and the woven or knitted fabric.

[0045] Examples of the polymeric elastomer include polyurethane, polyurea, polyurethane-polyurea, polyacrylic, etc. Since the polymeric elastomer plays the role of a binder that holds the ultrafine fibers contained in the artificial leather, in consideration of the soft texture of the artificial leather of the present invention, it is preferable that the polymeric elastomer used be polyurethane.

[0046] The polyurethane is obtained by the reaction of a polymer diol, an organic diisocyanate, and a chain extender, and either an organic solvent-based polyurethane, which is used in a dissolved state in an organic solvent, or a water-dispersed polyurethane, which is used in a dispersed state in water, can be used.

[0047] When the polymeric elastomer is polyurethane, the polymer diol may be, for example, a polycarbonate-based diol, a polyester-based diol, a polyether-based diol, a silicone-based diol, or a fluorine-based diol, or a copolymer of these may be used. Among these, from the viewpoints of hydrolysis resistance and abrasion resistance, it is preferable to use a polycarbonate-based diol.

[0048] Examples of polycarbonate-based diols include diols obtained by transesterification of alkylene glycol with carbonate ester, or by reaction of phosgene or chloroformate with alkylene glycol.

[0049] Examples of alkylene glycols used in polycarbonate-based diols include linear alkylene glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol, branched alkylene glycols such as neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, and 2-methyl-1,8-octanediol, alicyclic diols such as 1,4-cyclohexanediol, aromatic diols such as bisphenol A, glycerin, trimethylolpropane, and pentaerythritol. In the present invention, both polycarbonate-based diols obtained from a single alkylene glycol and copolymer polycarbonate-based diols obtained from two or more alkylene glycols can be used.

[0050] The polyester-based diols include diols obtained by condensing various low-molecular-weight polyols with polybasic acids.

[0051] Examples of low molecular weight polyols used in polyester diols include one or more selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, and adducts of various alkylene oxides with bisphenol A.

[0052] Examples of the polybasic acid used in the polyester diol include one or more selected from the group consisting of succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, and hexahydroisophthalic acid.

[0053] Furthermore, examples of polyether diols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymer diols obtained by combining these.

[0054] When the polymeric elastomer is polyurethane, the number-average molecular weight of the polymer diol is preferably in the range of 500 to 4000, provided that the molecular weight of the polyurethane elastomer is constant. By setting the number-average molecular weight to preferably 500 or more, more preferably 1500 or more, it is possible to prevent the artificial leather from becoming hard. Furthermore, by setting the number-average molecular weight to preferably 4000 or less, more preferably 3000 or less, it is possible to maintain the strength of the polyurethane.

[0055] Next, when the polymeric elastomer is polyurethane, examples of the organic diisocyanate include aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and xylylene diisocyanate, and aromatic diisocyanates such as diphenylmethane diisocyanate and tolylene diisocyanate, and these can also be used in combination.

[0056] When the elastomer is polyurethane, the chain extender may preferably be an amine-based chain extender such as ethylenediamine or methylenebisaniline, or a diol-based chain extender such as ethylene glycol. Alternatively, a polyamine obtained by reacting polyisocyanate with water may also be used as the chain extender.

[0057] Furthermore, when the polymeric elastomer is polyurethane, a crosslinking agent can be used in combination to improve water resistance, abrasion resistance, hydrolysis resistance, etc. The crosslinking agent may be an external crosslinking agent added to polyurethane as a third component, or an internal crosslinking agent that pre-introduces reactive points that form a crosslinked structure within the polyurethane molecular structure. From the viewpoint of forming crosslinked points more uniformly within the polyurethane molecular structure and reducing loss of flexibility, it is preferable to use an internal crosslinking agent.

[0058] As the crosslinking agent, a compound having an isocyanate group, an oxazoline group, a carbodiimide group, an epoxy group, a melamine resin, a silanol group, or the like can be used.

[0059] In the present invention, the mass proportion of the polymer elastomer in the artificial leather (hereinafter sometimes abbreviated as "mass proportion of polymer elastomer") is preferably 1.0 mass% or more and 25.0 mass% or less. When the mass proportion of the polymer elastomer is 1.0 mass% or more, preferably 5.0 mass% or more, the bonds between fibers by the polymer elastomer can be strengthened, resulting in an artificial leather with high abrasion resistance. On the other hand, when the mass proportion of the polymer elastomer is 25.0 mass% or less, more preferably 15.0 mass% or less, the degree of freedom of the woven or knitted fabric inside the artificial leather is increased, resulting in an artificial leather with high stretchability and flexibility despite its thickness.

[0060] The mass proportion of the polymeric elastomer in the artificial leather is measured and calculated by the following method. (1) Three test pieces measuring 20 cm in length and 20 cm in width are randomly taken from the artificial leather, and the mass of each test piece is measured. (2) The test piece is immersed in a solution containing dimethylformamide or the like to remove the polymeric elastomer and collect the ultrafine fibers. (3) Measure the mass of the collected ultrafine fibers, and calculate the mass ratio of the polymer elastomer in the test piece using the following formula: Mass ratio of polymer elastomer to test piece (%) = {(test piece mass) - (ultrafine fiber mass)} / (test piece mass) x 100 (4) For each of the three test pieces, calculate the mass percentage (%) of the polymer elastomer in each test piece, and round off the arithmetic mean value (%) to two decimal places to determine the mass percentage of the polymer elastomer in the artificial leather.

[0061] Furthermore, the polymeric elastomer may contain various additives depending on the purpose, such as "inorganic or oxide-based" pigments, "phosphorus-based, halogen-based, or inorganic" flame retardants, "phenol-based, sulfur-based, or phosphorus-based" antioxidants, "benzotriazole-based, benzophenone-based, salicylate-based, cyanoacrylate-based, or oxalic acid anilide-based" ultraviolet absorbers, "hindered amine-based or benzoate-based" light stabilizers, hydrolysis-resistant stabilizers such as polycarbodiimides, plasticizers, antistatic agents, surfactants, coagulation adjusters, and dyes.

[0062] [Artificial leather] The artificial leather of the present invention is an artificial leather comprising the fiber-entangled body and the polymeric elastomer, both surfaces of which are napped. From the viewpoint of design, it is preferable that the nap shape on the napped surface has such length and directional flexibility that when a finger is traced over the surface, the direction of the nap changes, leaving a mark, i.e., a so-called finger mark.

[0063] The average nap length of at least one surface of the artificial leather is preferably 200 μm or more and 600 μm or less. By setting the lower limit of the average nap length to preferably 200 μm or more, more preferably 250 μm, the surface smoothness of the artificial leather is improved, and an artificial leather with an excellent touch can be obtained. On the other hand, by setting the upper limit of the average nap length to preferably 600 μm or less, more preferably 500 μm or less, the artificial leather can be obtained with excellent abrasion resistance while maintaining a uniform and dense surface quality. The average nap length of the artificial leather can be adjusted by the grinding conditions in the "step of forming a nap-raised sheet" in the artificial leather manufacturing method described below.

[0064] Furthermore, the coefficient of variation of the nap length is preferably 50% or less. When the coefficient of variation of the nap length is preferably 50% or less, more preferably 40% or less, and even more preferably 30% or less, the area ratio of the polymeric elastomer exposed on the surface of the artificial leather is reduced, and the artificial leather tends to have both a uniform and dense surface quality and a smooth touch. There is no particular lower limit for the coefficient of variation of the nap length in the present invention.

[0065] In the present invention, the average nap length and the coefficient of variation of the nap length are measured and calculated by the following method. (1) Using a lint brush or the like, raise the nap of the artificial leather and prepare a thin section 1 mm thick in the cross-sectional direction perpendicular to the longitudinal direction of the artificial leather. (2) A cross section of the artificial leather is photographed at 90x magnification using a scanning electron microscope (SEM, for example, Keyence Corporation's "VHX-D500 / D510"). (3) In the SEM image, the bottom surface of the artificial leather (L in Fig. 1) is identified according to the schematic diagram of the cross section of the artificial leather shown in Fig. 1. B ) parallel to the line (L in Figure 1) A ) and draw perpendicular lines at 200 μm intervals. Here, the bottom surface of the artificial leather refers to the surface that is parallel to the horizontal surface when the artificial leather is placed on a horizontal surface with the wrinkles smoothed out. (4) Points X1 to X2 are placed on the boundary line (L0) between the raised part and the base part (described later). 10 Mark. (5) Points X1~X 10 Draw a perpendicular line from each point Y1 to Y2 in the direction of the napped portion and intersect with the tip of the napped layer. 10 Mark. (6) Find the distance Z1 between point X1 and point Y1, and then find Z 10 The average value (arithmetic mean) and coefficient of variation of the standing hair length are calculated by rounding off the average value (arithmetic mean) and coefficient of variation of the standing hair length to the first decimal place.

[0066] The artificial leather of the present invention is obtained by impregnating a fiber-entangled body with a polymeric elastomer, as shown in Fig. 1, and has piled portions 2 having a certain pile length arranged on both surfaces of the fiber-entangled body, and the remaining portion, a base portion 3. The base portion includes a woven or knitted fabric 4.

[0067] The fiber-entangled body of the artificial leather is formed by laminating a nonwoven fabric, a woven or knitted fabric, and another nonwoven fabric in this order, and each of the nonwoven fabrics has a thickness of 0.4 mm or more and 2.0 mm or less.

[0068] When the lower limit of the thickness of the nonwoven fabric is 0.4 mm or more, preferably 0.5 mm or more, more preferably 0.6 mm or more, an artificial leather having sufficient thickness and a rich feel can be obtained. On the other hand, when the upper limit of the thickness of the nonwoven fabric is 2.0 mm or less, preferably 1.5 mm or less, more preferably 1.0 mm or less, an artificial leather having excellent stretchability can be obtained.

[0069] In the present invention, the thickness of the nonwoven fabric is measured and calculated by the following method. (1) Using a lint brush or the like, raise the nap of the artificial leather and prepare a thin section 1 mm thick in the cross-sectional direction perpendicular to the longitudinal direction of the artificial leather. (2) A cross section of the artificial leather is photographed at 90x magnification using a scanning electron microscope (SEM, for example, Keyence Corporation's "VHX-D500 / D510"). (3) In the SEM image, the bottom surface of the artificial leather (L in Fig. 2) is identified according to the schematic diagram of the cross section of the artificial leather shown in Fig. 2. B ) parallel to the line (L in Figure 2) A ) and draw perpendicular lines at 200 μm intervals. (4) Among the intersections of the perpendicular line drawn in (3) and the woven or knitted fabric, the points S1 to S2 closest to the raised layer side of the nonwoven fabric where the thickness is to be measured are 10 Mark. (5) Points S1~S 10 Draw a perpendicular line in the direction of the raised part of the nonwoven fabric whose thickness is to be measured from each point T1 to T2. 10 Mark. (6) Let the distance between points S1 and T1 be U1, and similarly, U 10 The average value (arithmetic mean) is calculated as the thickness of the nonwoven fabric.

[0070] The thickness of the woven or knitted fabric of the artificial leather is preferably 0.05 mm or more and 0.35 mm or less.

[0071] When the lower limit of the thickness of the woven or knitted fabric is preferably 0.05 mm or more, more preferably 0.10 mm or more, an artificial leather with superior stretchability can be obtained. On the other hand, when the upper limit of the thickness of the nonwoven fabric is 0.35 mm or less, preferably 0.25 mm or less, an artificial leather with a softer feel can be obtained.

[0072] In the present invention, the thickness of the woven or knitted fabric is the thickness remaining after subtracting the thickness of the nonwoven fabric from the thickness of the artificial leather.

[0073] The nonwoven fabric in the artificial leather of the present invention satisfies the following formula in the cross section of the artificial leather: 1.2≦R1 / R2≦2.0 (Formula 1) Here, R1 is the area ratio (%) of the polymeric elastomer in the part closest to the napped side of the cross section of the artificial leather, obtained by dividing the area of ​​the nonwoven fabric excluding the napped part into three equal parts in the thickness direction, and R2 is the area ratio (%) of the polymeric elastomer in the part closest to the woven or knitted fabric of the cross section of the artificial leather, obtained by dividing the area of ​​the nonwoven fabric excluding the napped part into three equal parts in the thickness direction. In addition, in the present invention, the "cross section of the artificial leather" refers to a cross section perpendicular to the surface direction of the artificial leather.

[0074] By setting the lower limit of R1 / R2 to 1.2 or more, preferably 1.5 or more, the amount of polymeric elastomer bonded to the woven or knitted fabric is appropriately controlled, and the stretchability exhibited by the woven or knitted fabric is not excessively restricted, resulting in an artificial leather that is thick yet highly stretchable. On the other hand, by setting the upper limit of R1 / R2 to 2.0 or less, preferably 1.8 or less, a large amount of polymeric elastomer penetrates into the artificial leather, resulting in an artificial leather with a rich feel.

[0075] R1 / R2 in the artificial leather of the present invention can be adjusted, for example, by the needle punching conditions in the <step of forming the entangled sheet and nonwoven fabric β> in the method for producing an artificial leather described below.

[0076] Next, in the present invention, the area ratio of the polymer elastomer in the entire cross section of the artificial leather is preferably 0.1% or more and 10.0% or less. When the area ratio of the polymer elastomer in the entire cross section of the artificial leather (hereinafter sometimes abbreviated as "area ratio of polymer elastomer in cross section") is preferably 0.1% or more, more preferably 2.0% or more, and even more preferably 5.0% or more, the polymer elastomer is sufficiently bonded between the fibers, resulting in an artificial leather with good strength and abrasion resistance. On the other hand, when the area ratio of the polymer elastomer in the cross section is preferably 10.0% or less, more preferably 9.0% or less, and even more preferably 8.0% or less, an artificial leather with better elasticity can be obtained.

[0077] In the present invention, R1, R2, and the area ratio of the polymeric elastomer in the entire cross section of the artificial leather are calculated by the following method. (1) Five test pieces, each 0.5 cm long and 1.0 cm wide, are randomly taken from the artificial leather, and the internal space is embedded in epoxy resin. (2) The resin-embedded specimen is cut parallel to the thickness direction using a microtome. (3) The cut specimen is left to stand in saturated ruthenium tetroxide vapor for 4 hours, which causes the polymeric elastomer in the cross section of the artificial leather to be electronically dyed. (4) The cross section of the artificial leather is coated with 1 nm of osmium atoms to make it conductive. (5) The cross section of the artificial leather is observed at 500x magnification using a field emission scanning electron microscope (e.g., JEOL Ltd.'s "JSM-7800F Prime"). R1 ​​is calculated from 10 randomly taken SEM images of the most napped portion of the nonwoven fabric portion of the cross section of the artificial leather, obtained by dividing the area excluding the napped portion of the nonwoven fabric portion into three equal parts in the thickness direction. R2 is calculated from 10 randomly taken SEM images of the most napped portion of the nonwoven fabric portion of the cross section of the artificial leather, obtained by dividing the area excluding the napped portion of the nonwoven fabric portion into three equal parts in the thickness direction. Furthermore, the area ratio of the polymeric elastomer to the entire cross section of the artificial leather is calculated from 10 randomly taken SEM images of the cross section of the artificial leather. (6) The obtained SEM images are binarized using the image analysis software "ImageJ" or the like using the following method, and the area ratios (%) of R1, R2, and the polymer elastomer in the entire cross section of the artificial leather are calculated. (i) Filter the SEM image. The processing conditions are as follows: "Hand pass filtering" Filter large structures down to 40pixels Filter small structures up to 3pixels Suppress stipes: None Tolerance of direction: 5% Autoscale after filtering: Yes Saturate image when autoscaling: Yes Filter processing count: 1 "Median filtering" Radius: 4.0 Filter processing count: 1 (ii) Binarization is performed using the MaxEntropy method, and the black parts in the binarized SEM image are identified as polymeric elastomers. (iii) The obtained binarized image (1280 x 960 pixels) is divided into 32 x 32 pixel sections (1200 sections in this case), and the area percentage (%) of the polymer elastomer exposed in the cross section of each section is calculated using the Analyze Particle function of ImageJ (conditions: Size = 0-infinity, Circularity = 0.00-1.00). The total area of ​​each polymer elastomer distributed within each section is divided by the area of ​​each section, and the result is rounded to four decimal places. (iv) Read the number of pixels on the x and y axes of the target image, specify the partition size in pixel size, find the number of divisions on the x and y axes, and calculate the area ratio of the polymer elastomer within each divided region. The area ratio (%) of the polymer elastomer in R1, R2, and the entire cross section of the artificial leather is calculated by averaging the area ratio (%) of the polymer elastomer for all partitions and rounding to two decimal places.

[0078] When calculating R1 / R2, in (iv), R1 and R2 are rounded to three decimal places to calculate R1 / R2, and the resulting value is rounded to two decimal places to be used.

[0079] Furthermore, for R1, R2, and R1 / R2, calculate R1, R2, and R1 / R2 for each of the two nonwoven fabric portions in the cross section of the artificial leather, and use the smaller of the two calculated R1 / R2 values ​​as the result.

[0080] In the artificial leather of the present invention, the area ratio of the polymeric elastomer measured from the surface of the artificial leather is preferably 0.01% or more and 3.00% or less on both surfaces.

[0081] The area ratio of the polymer elastomer measured from the surface on both surfaces of the artificial leather (hereinafter sometimes abbreviated as "area ratio of the polymer elastomer on both surfaces") is preferably 0.01% or more, more preferably 0.05% or more, and even more preferably 0.10% or more, so that the ultrafine fibers present in the napped portion at the boundary between the napped portion (napped portion) and the non-napped portion (substrate portion) of the artificial leather are moderately gripped by the polymer elastomer, resulting in an artificial leather with excellent abrasion resistance on both surfaces. On the other hand, the area ratio of the polymer elastomer on both surfaces is preferably 3.00% or less, more preferably 2.00% or less, and even more preferably 1.00% or less, resulting in an artificial leather with a dense and smooth surface quality and a good feel on both surfaces.

[0082] The area ratio of the polymer elastomer on both surfaces of the artificial leather can be adjusted to fall within the above range by, for example, applying a water-soluble resin and a polymer elastomer within a predetermined range in the <step of forming a water-soluble resin-coated sheet> and the <step of forming a polymer elastomer-coated sheet> of the artificial leather manufacturing method described below, or by grinding both surfaces of the ultrafine fiber sheet under predetermined grinding conditions in the <step of forming a napped sheet>.

[0083] Furthermore, it is preferable that the standard deviation of the area proportion of the polymer elastomer on both surfaces (hereinafter sometimes abbreviated as "standard deviation of the area proportion of the polymer elastomer on both surfaces") is 25% or less. When the standard deviation of the area proportion of the polymer elastomer on the surface of the artificial leather is preferably 25% or less, more preferably 23% or less, and even more preferably 20% or less, the artificial leather will maintain a dense and smooth surface quality at all points on both surfaces of the artificial leather. There is no particular lower limit for the standard deviation of the area proportion of the polymer elastomer on both surfaces in the present invention.

[0084] In the present invention, the area ratio of the polymeric elastomer on both surfaces of the artificial leather and the standard deviation of the area ratio of the polymeric elastomer on both surfaces are calculated by the following method. (1) Five test pieces, each 0.5 cm long and 0.5 cm wide, were randomly taken from the artificial leather and left to stand in saturated ruthenium tetroxide vapor for four hours. This allowed the polyurethane exposed on the surface of the artificial leather to be electronically dyed. (2) The surface of the artificial leather is coated with 1 nm of osmium atoms to make it conductive. (3) The surface of the artificial leather is observed at 100x magnification using a field emission scanning electron microscope (for example, the JSM-7800F Prime manufactured by JEOL Ltd.), and calculations are performed from 10 SEM images taken randomly on the surface of the artificial leather. (4) The obtained SEM image is binarized using the image analysis software "ImageJ" or the like in the following manner, and the area ratio of the polymer elastomer on the surface of the artificial leather is calculated. (i) Filter the SEM image. The processing conditions are as follows: Bilateral Filter Fije Plugin Bilateral Filter spatial radius:3 range radius:50 Filter processing times: 5 times (ii) Binarization is performed using the MaxEntropy method, and the black parts in the binarized SEM image are identified as polymeric elastomers. (iii) The obtained binarized image (2560 × 1920 pixels) is divided into 32 × 32 pixel sections (4800 sections in this case), and the area percentage (%) of the polymer elastomer exposed on the surface of each section is calculated using the Analyze Particle function of ImageJ (conditions: Size = 0-infinity, Circularity = 0.00-1.00). The total area of ​​each polymer elastomer distributed within each section is divided by the area of ​​each section, and the result is rounded to four decimal places. (iv) Read the number of pixels on the x and y axes of the target image, specify the partition size in pixels, find the number of divisions on the x and y axes, and calculate the area percentage of the polymer elastomer within each divided area. The area percentage (%) of the polymer elastomer on the surface of the artificial leather is calculated by averaging the area percentage (%) of the polymer elastomer for all partitions and rounding to two decimal places. The standard deviation is an indicator of variation from the average value for all partitions and is calculated by rounding to two decimal places.

[0085] An example of image analysis software is the aforementioned image analysis software "ImageJ." However, image analysis software is not limited to "ImageJ" as long as it is image processing software that has the function of calculating the area ratio of specified pixels. Note that "ImageJ" is a commonly used software developed by the National Institutes of Health. The image processing software "ImageJ" has the function of identifying necessary areas in an imported image and performing pixel analysis.

[0086] In the present invention, the weight of the artificial leather is 200 g / m 2 More than 1200g / m 2 The weight of the artificial leather is preferably 200 g / m or less. 2 More preferably, 250 g / m 2 More preferably, 350 g / m 2 By setting the weight of the artificial leather to 1200 g / m or more, it is possible to obtain an artificial leather having a sufficient thickness and a feeling of fullness due to the texture. 2 Less than 800 g / m 2 or less, more preferably 500 g / m 2 By satisfying the condition of not more than 100%, an artificial leather having higher stretchability can be obtained.

[0087] The basis weight of the artificial leather of the present invention is measured in accordance with "6.2 Mass per unit area (ISO method)" of JIS L1913:2010 "Testing methods for general nonwoven fabrics," and is measured and calculated as follows. (1) Take three test pieces measuring 30 cm in length and 30 cm in width from the artificial leather. (2) Measure the mass of the test piece in (1). (3) Calculate the mass per unit area of ​​each test piece using the following formula: Mass per unit area (g / m 2 ) = mass of test piece (g) / area of ​​test piece (m 2 ) (4) The arithmetic mean value of the mass per unit area obtained in (3) (g / m 2 ) is rounded down to the nearest whole number and the resulting value is the basis weight of the artificial leather.

[0088] Furthermore, in an abrasion resistance test of the artificial leather of the present invention measured according to "8.19.5 Method E (Martindale method)" of "8.19 Abrasion resistance and discoloration due to friction" of JIS L1096:2010 "Testing methods for woven and knitted fabrics," the artificial leather is abraded 20,000 times at a pressure load of 12.0 kPa, and the loss in mass of the artificial leather after abrasion is preferably 10 mg or less, more preferably 8 mg or less, and even more preferably 6 mg or less. A mass loss of 10 mg or less can prevent contamination due to fluff shedding during actual use.

[0089] Regarding the abrasion resistance of the artificial leather, in order to keep the mass loss of the artificial leather within a predetermined range after being abraded 20,000 times with a pressing load of 12.0 kPa, it is believed that the friction between the naps can be reduced and the mass loss can be suppressed by adjusting the area ratio of the polymer elastomer on both surfaces of the artificial leather, and the average nap length and the coefficient of variation of the nap length within specific ranges.

[0090] The artificial leather of the present invention preferably has a tensile strength of 50 N / cm or more and 300 N / cm or less in both the longitudinal and transverse directions, as measured according to "6.3.1 Tensile strength and elongation (ISO method)" of JIS L1913:2010 "Testing methods for general nonwoven fabrics." A tensile strength of preferably 50 N / cm or more, more preferably 70 N / cm or more, results in an artificial leather with excellent shape stability and durability. Furthermore, a tensile strength of preferably 300 N / cm or less, more preferably 200 N / cm or less, results in an artificial leather with flexibility and excellent moldability.

[0091] Furthermore, the artificial leather of the present invention preferably has an elongation rate in the length (warp) direction or width (transverse) direction of 15% or more and 35% or less, as measured by "Method A (Constant Rate Elongation Method)" of "8.16.1 Elongation Rate" in JIS L1096:2010 "Testing Methods for Woven and Knit Fabrics." By setting the elongation rate to 15% or more, more preferably 20% or more, a good wearing comfort and a beautiful silhouette can be achieved when used in clothing, and good moldability can be achieved when used in the surface of clothing, hats, gloves, etc. Furthermore, by setting the elongation rate to 35% or less, more preferably 30% or less, good quality and good moldability can be ensured when elongated.

[0092] Furthermore, the artificial leather of the present invention preferably has a longitudinal and / or transverse elongation recovery rate of 75% or more and 100% or less, as measured by "B-2 Method (Constant Elongation Method after Elongation Measurement)" in "8.16.2 Elongation Modulus (Elongation Recovery Rate) and Residual Strain Rate" of JIS L1096:2010 "Testing Methods for Woven and Knit Fabrics." By ensuring that the elongation recovery rate is 75% or more, more preferably 80% or more, good stretch-back properties and shape retention can be achieved.

[0093] The artificial leather of the present invention preferably has a bending resistance in the warp or weft direction of 10 mm or more and 90 mm or less, as measured by "8.21.1 Method A (45° cantilever method)" of "8.21 Bending resistance" in JIS L1096:2010 "Testing methods for woven and knitted fabrics." By setting the bending resistance to 10 mm or more, more preferably 20 mm or more, good moldability and molding stability can be ensured. Furthermore, by setting the bending resistance to 90 mm or less, more preferably 70 mm or less, good comfort can be achieved when used as the surface of clothing, hats, gloves, etc.

[0094] In the present invention, the vertical direction of the artificial leather refers to the direction in which the artificial leather is raised. The method for determining the direction of the raised treatment can be appropriately adopted depending on the constituent components of the artificial leather, such as visual confirmation when tracing the surface with a finger or SEM photography. That is, the vertical direction is the direction in which the napped fibers can be laid down or raised when tracing the surface with a finger. Furthermore, by taking SEM photographs of the surface of the artificial leather traced with a finger, the vertical direction is determined to be the direction in which the majority of the lying napped fibers are oriented. Meanwhile, the horizontal direction of the artificial leather of the present invention refers to the direction perpendicular to the vertical direction within the plane of the artificial leather.

[0095] [Manufacturing method for artificial leather] Furthermore, an example of a method for producing the artificial leather of the present invention will be described.

[0096] The method for producing an artificial leather of the present invention includes the steps of: (1) entangling a woven or knitted fabric on one side of nonwoven fabric α made of ultrafine fiber-developing fibers to form an entangled sheet; (2) forming nonwoven fabric β made of ultrafine fiber-developing fibers; (3) laminating the entangled sheet and nonwoven fabric β so that the woven or knitted fabric is sandwiched between nonwoven fabrics α and β and entangling them by needle punching to form a precursor sheet; (4) applying a water-soluble resin to the precursor sheet to form a water-soluble resin-coated sheet; (5) applying an elastomer to the water-soluble resin-coated sheet to form a polymeric elastomer-coated sheet; (6) generating ultrafine fibers from the ultrafine fiber-developing fibers in the polymeric elastomer-coated sheet to form an ultrafine fiber sheet; and (7) grinding both surfaces of the ultrafine fiber sheet to form a raised sheet. Step (1) preferably includes the steps of producing ultrafine fiber-developing fibers and forming an entangled sheet. It is also preferable to carry out a post-process following the process (7). Each process will be described in detail below.

[0097] <Process for producing ultrafine fiber-developing fibers> In this process, ultrafine fiber-developing fibers are formed. Ultrafine fiber-developing fibers refer to fibers that can be transformed into ultrafine fibers by the methods described below. Specific examples include islands-in-sea composite fibers, in which thermoplastic resins with different solvent solubilities are used to form a sea portion (easily soluble polymer) and an island portion (slightly soluble polymer), and the sea portion is dissolved and removed using a solvent or the like to form ultrafine fibers from the island portion. Alternatively, peel-type composite fibers are used, in which two thermoplastic resin components with different solvent solubilities are alternately arranged radially or in multiple layers on the fiber cross section, and the components are peeled and split to form ultrafine fibers. Among these, islands-in-sea composite fibers are more preferred from the viewpoints of the texture and surface quality of the artificial leather, and because appropriate voids can be created between the island portions, i.e., between the ultrafine fibers within the fiber bundle, when the sea portion is removed. The resulting ultrafine fiber-developing fibers are sometimes commonly referred to as raw cotton.

[0098] As a method for spinning ultrafine fiber-producing fibers having an islands-in-sea composite structure, a method using a spinneret for islands-in-sea composite fibers and a polymer mutually aligned structure in which sea parts and island parts are mutually aligned and spun is preferred from the viewpoint of obtaining ultrafine fibers with a uniform single fiber diameter.

[0099] For the sea portion of the islands-in-sea type composite fiber, polyethylene, polypropylene, polystyrene, copolymer polyesters copolymerized with sodium sulfoisophthalic acid, polyethylene glycol, etc., and polylactic acid, etc. can be used. From the viewpoints of spinnability, ease of elution, etc., polystyrene and copolymer polyesters are preferably used.

[0100] When the ultrafine fiber-developing fiber is an islands-in-sea type composite fiber, it is preferable to use an islands-in-sea type composite fiber whose island portions have a tensile strength (tensile strength of the ultrafine fibers) of 2.2 cN / dtex or more. By making the tensile strength of the island portions preferably 2.2 cN / dtex or more, more preferably 3.0 cN / dtex or more, and even more preferably 4.0 cN / dtex or more, the abrasion resistance of the artificial leather can be improved and a decrease in friction fastness due to fiber shedding can be suppressed.

[0101] In the present invention, the tensile strength of the island parts of the islands-in-sea type composite fiber (tensile strength of the ultrafine fibers) is calculated by the following method. (1) Ten 20cm long islands-in-the-sea composite fibers are bundled together. (2) After dissolving and removing the sea area from the sample (1), air dry it. (3) According to JIS L1013:2010 "Testing methods for chemical fiber filament yarns", "8.5 Tensile strength and elongation", "8.5.1 Standard time test", the test shall be carried out 10 times (N=10) under the conditions of grip length 5 cm, pulling speed 5 cm / min, and load 2 N. (4) The arithmetic mean value (cN / dtex) of the test results obtained in (3) is rounded to two decimal places, and the resulting value is the tensile strength of the island parts of the islands-in-sea type composite fiber, i.e., the tensile strength of the ultrafine fibers.

[0102] <Step of forming entangled sheet and nonwoven fabric β> In this step, for example, the ultrafine fiber development type fibers spun as described above are opened and then formed into a fiber web (nonwoven fabric α) using a cross wrapper or the like, and the woven or knitted fabric is laminated and entangled on one side of this to form an entangled sheet in which the nonwoven fabric α formed by entanglement of the ultrafine fiber development type fibers and the woven or knitted fabric are entangled and integrated.

[0103] The entanglement method preferably uses needle punching. By using needle punching, a thick entangled sheet can be formed, and an artificial leather having a sufficient thickness and a rich feel can be obtained.

[0104] Similarly to the nonwoven fabric α, the nonwoven fabric β can also be obtained by, for example, opening the spun ultrafine fiber-developing fibers and then forming them into a fiber web using a crosswrapper or the like. The fiber web is preferably subjected to a needle punching process to entangle the ultrafine fiber-developing fibers. The needle punching process can produce a thick nonwoven fabric β, allowing for the production of an artificial leather that is sufficiently thick and has a rich texture.

[0105] As for the form of the nonwoven fabrics α and β, either short fiber nonwoven fabric or long fiber nonwoven fabric can be used as described above. However, when using short fiber nonwoven fabric, the number of fibers oriented in the thickness direction of the artificial leather is greater than that of long fiber nonwoven fabric, and a highly dense feel can be achieved on the surface of the artificial leather when raised.

[0106] When the nonwoven fabrics α and β are made of staple fiber, the ultrafine fiber-developing fibers are preferably subjected to crimping processing, and then cut to a predetermined length to obtain raw cotton, which is then opened, laminated, and entangled to obtain the staple fiber nonwoven fabric. Known methods can be used for crimping and cutting.

[0107] In the present invention, the entangled sheet at the stage where the nonwoven fabric α and the woven or knitted fabric are entangled and integrated satisfies the following formula 2: 0.50≦V A1 / V A2 ≦0.80 (Formula 2) where VA1 is the apparent density (g / cm) of the nonwoven fabric α in the region containing the woven or knitted fabric on the surface of one of two regions obtained by dividing the cross section of the entangled sheet into two equal regions in the thickness direction. 3 ) and V A2 is the apparent density (g / cm) of the nonwoven fabric α in the region containing the nonwoven fabric α on the surface of one of two regions obtained by dividing the cross section of the entangled sheet into two equal parts in the thickness direction. 3 )

[0108] Since the nonwoven fabric α is sufficiently thick compared to the thickness of the woven or knitted fabric, the cross section of the entangled sheet is divided into two equal regions as described above when it is divided into two equal parts in the thickness direction.

[0109] The above V A1 / V A2 When the lower limit of V is 0.50 or more, preferably 0.60 or more, the nonwoven fabric α and the woven or knitted fabric are suitably entangled, and the entire artificial leather can follow the high stretchability exhibited by the woven or knitted fabric, thereby obtaining an artificial leather that is thick yet has high stretchability. A1 / V A2 When the upper limit of is 0.80 or less, preferably 0.70 or less, the space to which the water-soluble resin is applied in the <Step of Forming a Water-Soluble Resin-Coated Sheet> described below can be made larger near the woven or knitted fabric of the precursor sheet compared to the space near the surface layer of the precursor sheet, and the distribution ratio R1 / R2 of the polymer elastomer in the cross section of the artificial leather can be kept within a predetermined range, thereby obtaining an artificial leather that is thick yet highly stretchable.

[0110] The apparent density V of the two regions in the entangled sheet in which the nonwoven fabric α and the woven / knitted fabric are entangled and integrated A1 , V A2 As a method for creating a difference in the density of needle punches (counts / cm) from the side where the woven or knitted fabric is laminated in the step of forming the entangled sheet, 2 ):D a1 The needle punch density (counts / cm) from the side where the woven / knitted fabric is laminated and the opposite side 2 ):D a2Furthermore, the above D a1 and D a2 It is preferable that the following formula be satisfied: 0.10≦D a1 / D a2 ≦0.80 The above D a1 / D a2 The lower limit of D is preferably 0.10 or more, more preferably 0.30 or more. a1 / D a2 The upper limit of is preferably 0.80 or less, more preferably 0.60 or less.

[0111] In addition, when forming the nonwoven fabric β, the nonwoven fabric β is formed so as to satisfy the following formula before being entangled and integrated with the entangled sheet in the <step of forming a precursor sheet> described later. 0.50≦V β1 / V β2 ≦0.80 (Equation 3) where V β1 is the apparent density (g / cm) of the nonwoven fabric β in the part of the nonwoven fabric β that is the woven / knitted fabric side in a region that is equally divided in the thickness direction in the cross section of the nonwoven fabric β before being entangled and integrated in the <step of forming a precursor sheet> described later. 3 ) and V β2 is the apparent density (g / cm) of the nonwoven fabric β in the part that is not on the woven / knitted fabric side in a region that is equally divided in the thickness direction in the cross section of the nonwoven fabric β before being entangled and integrated in the <step of forming a precursor sheet> described later. 3 )

[0112] The above V β1 / V β2 When the lower limit of V is 0.50 or more, preferably 0.60 or more, the nonwoven fabric β and the woven or knitted fabric of the entangled sheet are entangled to a suitable degree when they are entangled and integrated in the <step of forming a precursor sheet> described later, and the entire artificial leather can follow the high stretchability exhibited by the woven or knitted fabric, thereby making it possible to obtain an artificial leather that is thick yet has high stretchability. β1 / V β2When the upper limit of is 0.80 or less, preferably 0.70 or less, the space to which the water-soluble resin is applied in the <Step of Forming a Water-Soluble Resin-Coated Sheet> described below can be made larger near the woven or knitted fabric of the precursor sheet compared to the space near the surface layer of the precursor sheet, and the distribution ratio R1 / R2 of the polymer elastomer in the cross section of the artificial leather can be kept within a predetermined range, thereby obtaining an artificial leather that is thick yet highly stretchable.

[0113] The apparent density V of the two regions in the nonwoven fabric β β1 , V β2 As a method for creating a difference in the density of needle punches (counts / cm) from the surface side of the nonwoven fabric β, which is the side on which the woven or knitted fabric is laminated, when needle punching is performed in the process of forming the nonwoven fabric β, for example, 2 ):D b1 The needle punch density (number / cm) from the surface side of the precursor sheet 2 ):D b2 This can be adjusted by making it smaller than

[0114] Furthermore, the above D b1 and D b2 It is preferable that the following formula is satisfied: 0.15≦D b1 / D b2 ≦0.70 The above D b1 / D b2 The lower limit of D is preferably 0.15 or more, more preferably 0.30 or more. b1 / D b2 The upper limit of is preferably 0.70 or less, and more preferably 0.60 or less.

[0115] The entangled sheet and the nonwoven fabric β satisfy the following formula before the nonwoven fabric β and the entangled sheet are entangled and integrated in the <step of forming a precursor sheet> described later. 0.30≦V β3 / V A ≦0.80 (Formula 4) where V Ais the apparent density (g / cm) of the entangled sheet before the entanglement and integration. 3 ) and V β3 is the apparent density (g / cm 3 ) of the nonwoven fabric β before the entanglement and integration 3 )

[0116] The above V β3 / V A When the lower limit of V is 0.30 or more, preferably 0.40 or more, the entanglement state of the nonwoven fabrics α and β in the precursor sheet obtained in the <step of forming a precursor sheet> described later, such as the apparent density and the density difference in the thickness direction, can be made approximately equal, and artificial leather having an elegant surface appearance on both surfaces can be obtained. β3 / V A When the upper limit of is 0.80 or less, preferably 0.60 or less, the woven or knitted fabric of the entangled sheet is suitably entangled with the nonwoven fabric β when they are entangled and integrated in the <step of forming a precursor sheet> described below, and the entire artificial leather can follow the high stretchability exhibited by the woven or knitted fabric, thereby obtaining an artificial leather that is thick yet has high stretchability.

[0117] Furthermore, the V A and V β3 However, both are 0.01g / cm 3 More than 0.30g / cm 3 By setting the thickness within the above range, the woven or knitted fabric of the entangled sheet is sufficiently entangled with the nonwoven fabric β when they are entangled and integrated in the <Step of forming a precursor sheet> described below, and the entire artificial leather can follow the high stretchability exhibited by the woven or knitted fabric, thereby obtaining an artificial leather having high stretchability.

[0118] The apparent density V of the entangled sheet A1 , V A2 and the apparent density V of the nonwoven fabric β β1 , V β2 is measured and calculated as follows: (1) Three test pieces, each 30 cm long and 30 cm wide, are taken from any location on the entangled sheet or nonwoven fabric β. (2) Cut the test piece taken in (1) in half thicknesswise. (3) For test pieces cut in half in (2) that have intertwined woven or knitted fabrics, peel off the woven or knitted fabrics while minimizing deformation of the test piece. (4) Measure the mass of the test piece obtained in (2) or (3). (5) Calculate the apparent density of each test piece using the following formula: Apparent density (g / cm 3 ) = mass of test piece (g) / {area of ​​test piece (cm 2 ) × thickness of test piece (cm) (6) The arithmetic mean value of the apparent density (g / cm) obtained in (5) 3 ) to the third decimal place, calculate to the second decimal place, and V A1 , V A2 , V β1 , and ,V β2 Let's say.

[0119] The apparent density V of the entangled sheet A and the apparent density V of the nonwoven fabric β β3 is measured and calculated as follows: (1) Three test pieces, each 30 cm long and 30 cm wide, are taken from any location on the entangled sheet or nonwoven fabric β. (2) Measure the mass of the test piece obtained in (1). (3) Calculate the apparent density of each test piece using the following formula: Apparent density (g / cm 3 ) = mass of test piece (g) / {area of ​​test piece (cm 2 ) × thickness of test piece (cm) (4) The arithmetic mean value of the apparent density (g / cm) obtained in (3) 3 ) to the third decimal place, calculate to the second decimal place, and V A and V β3 Let's say.

[0120] <Step of forming precursor sheet> In this step, the entangled sheet and the nonwoven fabric β are laminated so that the woven or knitted fabric is sandwiched between the nonwoven fabric α and the nonwoven fabric β, and then entangled and integrated by needle punching to form a precursor sheet.

[0121] In the needle punching process for forming the precursor sheet, the following formula is satisfied: 0.30≦D A / D β ≦0.70 (Equation 5) where D A is the density of needle punches punched from the entangled sheet side (numbers / cm 2 ) and D β is the needle punch density (counts / cm) punched from the β side of the nonwoven fabric 2 )

[0122] The above D A / D β The lower limit of D is 0.30 or more, preferably 0.40 or more. A / D β When the upper limit of is 0.70 or less, preferably 0.60 or less, the apparent density, the difference in density in the thickness direction, and the entanglement state of the nonwoven fabric α and the nonwoven fabric β in the obtained precursor sheet can be made approximately equivalent, and an artificial leather having an elegant surface appearance on both surfaces can be obtained.

[0123] The apparent density of the precursor sheet is 0.15 g / cm 3 More than 0.35g / cm 3 The apparent density is preferably 0.15 g / cm or less. 3 More preferably, 0.20 g / cm 3 By setting the apparent density to 0.35 g / cm or more, a dense feeling can be obtained in the raised nap, and an artificial leather excellent in surface quality and feel can be obtained. 3 or less, more preferably 0.30 g / cm 3By doing so, sufficient space can be maintained for applying the water-soluble resin and the polymer elastomer in the <step of forming a sheet with water-soluble resin> and <step of forming a sheet with polymer elastomer> described below, and the area ratio of the polymer elastomer in the cross section of the finally obtained artificial leather can be kept within a predetermined range.

[0124] It is also a preferred embodiment that the precursor sheet is subjected to a heat shrinking treatment using hot water or steam in order to improve the denseness of the fibers.

[0125] Here, the apparent density of the precursor sheet is measured and calculated as follows. (1) Three test pieces, each 30 cm long and 30 cm wide, are taken from any location on the precursor sheet. (2) Measure the mass of the test piece obtained in (1). (3) Calculate the apparent density of each test piece using the following formula: Apparent density (g / cm 3 ) = mass of test piece (g) / {area of ​​test piece (cm 2 ) × thickness of test piece (cm) (4) The arithmetic mean value of the apparent density (g / cm) obtained in (3) 3 ) is rounded to two decimal places to obtain the apparent density of the precursor sheet.

[0126] <Step of forming a water-soluble resin-coated sheet> In this step, a water-soluble resin is applied to the precursor sheet to form a water-soluble resin-coated sheet.

[0127] Examples of water-soluble resins include polyvinyl alcohol, polyethylene oxide, polyacrylamide, resol-type phenolic resin, methylolated urea resin, methylolated melamine resin, carboxymethyl cellulose, etc. This water-soluble resin adheres to the surface of the ultrafine fiber-patterning fiber contained in the precursor sheet and plays a role in preventing strong adhesion between the polymeric elastomer and the ultrafine fiber-patterning fiber when the polymeric elastomer is imparted as described below. Therefore, in consideration of the stretchability of the artificial leather of the present invention, it is preferable that the water-soluble resin used be polyvinyl alcohol.

[0128] The water-soluble resin is preferably applied in an amount ranging from 25% to 50% by mass relative to the mass of the precursor sheet. By applying this amount, preferably 25% by mass or more, more preferably 30% by mass or more, the presence of the water-soluble resin in the step of applying the polymer elastomer moderately alleviates adhesion between the fibers and the polymer elastomer, while the area ratio of the polymer elastomer in the cross section of the artificial leather is within a predetermined range, resulting in an artificial leather that is thick yet highly stretchable. On the other hand, by applying the water-soluble resin in an amount preferably 50% by mass or less, more preferably 45% by mass or less, the mass ratio of the polymer elastomer in the artificial leather is within a predetermined range in the step of applying the polymer elastomer, resulting in an artificial leather with good texture and surface quality. The water-soluble resin may be, for example, prepared as an aqueous solution of the water-soluble resin, which may be impregnated into the precursor sheet and then dried.

[0129] In this step, it is preferable to include polyethylene glycol in an amount of 0.01% by mass or more and 0.50% by mass or less relative to the mass of the water-soluble resin. By setting the polyethylene glycol content to preferably 0.01% by mass or more, more preferably 0.10% by mass or more, foaming of the water-soluble resin can be suppressed and the preparation time can be shortened when preparing the aqueous solution of the water-soluble resin. On the other hand, by setting the polyethylene glycol content to preferably 0.50% by mass or less, more preferably 0.30% by mass or less, the water-soluble resin can be applied to the precursor sheet in a uniform size, and the area ratio of the polymeric elastomer in the cross section of the final artificial leather can be kept within a predetermined range.

[0130] <Step of forming a sheet with elastic polymer> In this step, the polymeric elastomer is applied to the water-soluble resin-coated sheet to form a polymeric elastomer-coated sheet. Preferably, the polymeric elastomer is applied in an amount of 4% to 20% by mass relative to the mass of the water-soluble resin-coated sheet. More specifically, the water-soluble resin-coated sheet is impregnated with a solution of a polymeric elastomer precursor so that the amount applied is 4% to 20% relative to the mass of the water-soluble resin-coated sheet, and then solidified to form a polymeric elastomer-coated sheet. Here, the polymeric elastomer precursor refers to a precursor (hereinafter sometimes simply referred to as "precursor") that will become a polymeric elastomer by means of coagulation or solidification, as described below. For example, if the polymeric elastomer is polyurethane, the polyurethane precursor is a mixture of the polyurethane's reactive components, i.e., polymer diol, organic diisocyanate, chain extender, etc.

[0131] In the present invention, in order to achieve both a darker and more uniform color development, a polymeric elastomer containing a black pigment can be applied to the water-soluble resin-coated sheet by, for example, incorporating the black pigment into a precursor of the polymeric elastomer.

[0132] As the solvent used when applying the polymeric elastic material to the water-soluble resin-coated sheet, N,N'-dimethylformamide, dimethyl sulfoxide, or the like is preferred.

[0133] In this step, after the polymer elastomer is applied, it is preferable to remove the water-soluble resin applied in the <step of forming a water-soluble resin-attached sheet> from the viewpoint of making the texture of the artificial leather soft. One method for removing the water-soluble resin is to immerse the polymer elastomer-applied sheet in water heated to 65°C to 95°C (hot water) and then dry the sheet.

[0134] <Process for forming ultrafine fiber sheet> In this step, ultrafine fibers having an average single fiber diameter of 0.01 μm or more and 10.00 μm or less are produced from the ultrafine fiber-producing fibers of the polymeric elastomer-attached sheet, to form an ultrafine fiber sheet.

[0135] Ultrafine fibers having an average single fiber diameter within the above range can be produced from the ultrafine fiber-producing fibers of the polymeric elastomer-attached sheet by, for example, immersing the polymeric elastomer-attached sheet in a solvent. When the ultrafine fiber-producing fibers are islands-in-sea composite fibers, the production can be achieved by, for example, dissolving and removing the sea portion.

[0136] When the ultrafine fiber-developing fiber is an islands-in-sea type composite fiber, the solvent for dissolving and removing the sea portion can be an organic solvent such as toluene or trichloroethylene if the sea portion is made of polyethylene, polypropylene, or polystyrene. Alternatively, an alkaline aqueous solution such as sodium hydroxide can be used if the sea portion is made of copolymer polyester or polylactic acid. Alternatively, hot water (water at 70°C to 99°C) can be used if the sea portion is made of a water-soluble thermoplastic polyvinyl alcohol resin.

[0137] Furthermore, by repeatedly immersing the polymeric elastomer-attached sheet in a solvent and squeezing and compressing it with a mangle, ultrafine fibers can be efficiently produced from the ultrafine fiber-producing fibers.

[0138] <Step of forming the raised sheet> In this step, both surfaces of the ultrafine fiber sheet are ground. This raises the surface and forms a napped portion. For this grinding, grinding means such as sandpaper or a roll sander are preferably used.

[0139] To obtain artificial leather with excellent surface quality on both sides, the grinding of the ultrafine fiber sheet is preferably carried out in multiple stages, preferably two or more times, more preferably three or more times, for each surface of the ultrafine fiber sheet using a grinding means. Furthermore, it is more preferable that the grit size of the sandpaper or roll sander used in each stage be gradually finer, or at least be the same.

[0140] The grit size of the sandpaper or roll sander used to grind the surface of the ultrafine fiber sheet (corresponding to the surface of the artificial leather) is preferably in the range of #100 or more and #320 or less, as specified in JIS R6610:2000 "Grit size of abrasives for abrasive cloths." By using a grit size of the sandpaper or roll sander of preferably #100 or more, more preferably #120 or more, the average nap length of the napped portion of the artificial leather falls within a preferred range, resulting in an artificial leather with an excellent feel to the touch. On the other hand, by using a grit size of the sandpaper or roll sander of preferably #320 or less, more preferably #240 or less, the artificial leather has a dense feel and a uniform, elegant surface quality.

[0141] When each surface of the ultrafine fiber sheet is ground multiple times with a grinding means, the conveying speed of the ultrafine fiber sheet is preferably 5 m / min or more and 20 m / min or more. By setting the conveying speed of the ultrafine fiber sheet to preferably 5 m / min or more, more preferably 7 m / min or more, it is possible to achieve good productivity while keeping the average pile length within a preferred range. On the other hand, by setting the conveying speed of the ultrafine fiber sheet to preferably 20 m / min or less, more preferably 15 m / min or less, it is possible to suppress the equipment load and keep the area ratio of the polymeric elastomer measured from the surface of the artificial leather within a preferred range, thereby obtaining artificial leather with a dense and uniform surface quality. Note that the conveying speed of the ultrafine fiber sheet here refers to the speed at which the sheet is fed to a roll or roll sander rotating sandpaper at high speed.

[0142] The grinding speed is preferably 200 m / min or more and 1000 m / min or less. By setting the grinding speed to preferably 200 m / min or more, more preferably 300 m / min or more, it is possible to suppress the load on the equipment while keeping the average nap length within a preferred range and obtain an artificial leather with an excellent touch. On the other hand, by setting the grinding speed to preferably 1000 m / min or less, more preferably 900 m / min or less, it is possible to keep the area ratio of the polymeric elastomer measured from the surface of the artificial leather within a preferred range and obtain an artificial leather with a dense and uniform surface quality. The grinding speed here refers to the peripheral speed calculated from the rotation speed and peripheral length of the sandpaper or roll sander, and can be calculated specifically by the following formula: Grinding speed (m / min) = {sandpaper or roll sander rotation speed (rpm)} x {sandpaper or roll sander circumference (m)} Before grinding, a lubricant such as a silicone emulsion can be applied to the surface of the ultrafine fiber sheet. Also, by applying an antistatic agent to the ultrafine fiber sheet before grinding, grinding dust generated from the artificial leather during grinding is less likely to accumulate on the sandpaper.

[0143] Here, the raised sheet obtained after grinding has a basis weight of 250 g / m2 More than 1500g / m 2 The weight of the raised sheet obtained after grinding is preferably 250 g / m or less. 2 More preferably, 350 g / m 2 By satisfying the above conditions, an artificial leather having a sufficient thickness and a rich feel can be obtained. On the other hand, the weight of the raised sheet is preferably 1500 g / m 2 or less, more preferably 1000 g / m 2 More preferably, 700 g / m or less 2 By satisfying the above condition, an artificial leather having high stretchability can be obtained.

[0144] The basis weight of the raised sheet is measured and calculated as follows. (1) Take three test pieces measuring 30 cm in length and 30 cm in width from any location on the raised sheet. (2) Measure the mass of the test piece obtained in (1). (3) Calculate the mass per unit area of ​​each test piece using the following formula: Mass per unit area (g / m 2 ) = mass of test piece (g) / area of ​​test piece (m 2 ). (4) The arithmetic mean value of the mass per unit area obtained in (3) (g / m 2 ) is rounded down to the nearest whole number and the resulting value is the basis weight of the raised sheet.

[0145] <Post-process> Furthermore, the raised sheet can also be dyed.

[0146] Examples of dyeing methods that can be used include jet dyeing using a jigger dyeing machine or jet dyeing machine, dip dyeing such as thermosol dyeing using a continuous dyeing machine, or printing on napped surfaces using roller printing, screen printing, inkjet printing, sublimation printing, vacuum sublimation printing, etc. Among these, jet dyeing machines are preferred in terms of quality and grade, as they provide a soft texture. Furthermore, various resin finishing processes can be applied after dyeing, if necessary.

[0147] The sheet obtained as described above can be used as artificial leather as is, but if necessary, various surface treatments can be applied to the sheet to produce artificial leather with excellent design. For example, post-processing such as perforation, embossing, laser processing, pinsonic processing, and printing can be applied. In addition, various resin finishing processes can be applied.

[0148] [Application] The artificial leather of the present invention obtained by the above-exemplified production method has an elegant surface appearance on both surfaces, and has high stretchability despite its great thickness, making it a material particularly suitable for use in clothing, miscellaneous goods, etc.

[0149] Among these, clothing containing the artificial leather is preferred because it can take advantage of the elegant surface appearance on both surfaces, the rich texture, and the excellent elasticity. Examples of such clothing include tops such as T-shirts, polo shirts, dress shirts, blouses, wrap tops, cut-and-sew tops, sweaters, vests, hoodies, sweatshirts, turtlenecks, cardigans, tank tops, and tube tops; outerwear such as coats, blazers, jackets, windbreakers, cloaks, capes, aprons, and mantles; trousers such as slacks, jeans, and shorts; skirts; dresses such as cocktail dresses, one-piece dresses, and gowns; formal wear, suits, uniforms, and underwear.

[0150] Similarly, miscellaneous goods containing the artificial leather are also preferred, since they can take advantage of the properties of the elegant surface appearance on both surfaces, the rich texture, and the excellent high stretchability.

[0151] Examples of such miscellaneous goods include hats such as fedoras, bowler hats, top hats, pork pie hats, crochet hats, capelins, canotier hats, metro hats, tulip hats, bucket hats, boonie hats, 6-panel caps, trucker caps, jet caps, hunting caps, newsboy caps, marine caps, work caps, trapper caps, knit caps, and berets; gloves such as shorty gloves, demi-gloves, open-finger gloves, fingerless gloves, cut-out gloves, mittens, gauntlets, lace gloves, half-scoop gloves, training gloves, shooting gloves, drawing gloves, hand guards, opera gloves, arm longs, bucket gloves, corset gloves, arm covers, arm warmers, and musk tail gloves; accessories such as belts, scarves, head wraps, hair bands, ear mufflers, and ties; shoe upper trims; bags; and wallets. [Example]

[0152] Next, the artificial leather of the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

[0153] [Measurement method and evaluation processing method] The evaluation methods and measurement conditions used in the examples are explained below, except that unless otherwise specified, the measurements of each physical property were carried out according to the above-mentioned methods.

[0154] (1) Average single fiber diameter of ultrafine fibers (μm): In measuring the average single fiber diameter of ultrafine fibers, ultrafine fibers were observed using a scanning electron microscope (SEM) model "VHX-D500 / D510" manufactured by Keyence Corporation, and the average single fiber diameter was calculated.

[0155] (2) Tensile strength of ultrafine fibers (cN / dtex): The tensile strength of the ultrafine fibers was measured using the Tensilon universal material testing machine "RTC-1350A" manufactured by A&D Co., Ltd., and was measured and calculated using the method described above.

[0156] (3) Apparent density V of the entangled sheet A1 , V A2 , V A , the apparent density V of the nonwoven fabric β β1 , V β2 , V β3 and the apparent density of the precursor sheet (g / cm 3 ): The apparent density was measured and calculated by the method described above.

[0157] (4) Basis weight of precursor sheet and raised sheet (g / m 2 ): The basis weights of the precursor sheet and the raised sheet were measured and calculated as follows. (i) Take three test pieces measuring 30 cm in length and 30 cm in width from any location on the sheet. (ii) Measure the mass of the test piece obtained in (i). (iii) Calculate the mass per unit area of ​​each test piece using the following formula: Mass per unit area (g / m 2 ) = mass of test piece (g) / area of ​​test piece (m 2 ) (iv) The arithmetic mean value of the mass per unit area obtained in (iii) (g / m 2 ) is rounded down to the nearest whole number and the value obtained is the basis weight of the sheet.

[0158] (5) Thickness of artificial leather (mm): The thickness of the artificial leather was measured and calculated using a thickness gauge called "Peacock Dial Thickness Gauge H" manufactured by Ozaki Seisakusho Co., Ltd. The thickness of the artificial leather was determined by taking the arithmetic mean value of the thickness measured at 10 arbitrary locations on the artificial leather and rounding it off to two decimal places.

[0159] (6) Thickness of the nonwoven fabric part of the artificial leather (mm): To measure the thickness of the nonwoven fabric portion of the artificial leather, a scanning electron microscope (SEM) VHX-D500 / D510 manufactured by Keyence Corporation was used to observe the cross section of the artificial leather, and the thickness of the nonwoven fabric portion of the artificial leather was calculated.

[0160] (7) Artificial leather weight (g / m 2 ): The basis weight of the artificial leather was measured and calculated by the above-mentioned method.

[0161] (8) Area ratio (%) of R1 and R2 in the cross section of the artificial leather and the polymer elastomer in the entire cross section of the artificial leather: In the above measurements, a field emission scanning electron microscope "JSM-7800F Prime" manufactured by JEOL Ltd. was used, and "ImageJ" was used as image analysis software, and measurements and calculations were carried out according to the above methods.

[0162] (9) Mass ratio of polymer elastomer (mass%): The mass proportion of the polymeric elastomer was measured and calculated using dimethylformamide as a solvent.

[0163] (10) Area percentage (%) of polymeric elastomer measured on the surface of artificial leather and its standard deviation (%): In the above measurements, a field emission scanning electron microscope "JSM-7800F Prime" manufactured by JEOL Ltd. was used, and measurements and calculations were carried out using "ImageJ" as image analysis software.

[0164] (11) Average nap length (μm) and its coefficient of variation (%) of artificial leather: To measure the average nap length of the artificial leather, a scanning electron microscope (SEM) VHX-D500 / D510 manufactured by Keyence Corporation was used to observe the cross section of the artificial leather, and the average nap length and its coefficient of variation of the artificial leather were calculated.

[0165] (12) Elongation rate of artificial leather (%): The elongation percentage of the artificial leather was measured and calculated by the method described above. In the present invention, a satisfactory level is an elongation percentage of 15% or more and 35% or less.

[0166] (13) Elongation recovery rate (%) of artificial leather: The elongation recovery rate of the artificial leather was measured and calculated by the method described above. In the present invention, a good level is 75% or more and 100% or less.

[0167] (14) Bending resistance of artificial leather (mm): The bending resistance of the artificial leather was measured and calculated by the above-mentioned method.

[0168] (15) Tensile strength of artificial leather (N / cm): Two test pieces measuring 2cm x 20cm were taken from each of the longitudinal and transverse directions of the artificial leather, and the tensile strength (N / cm) was measured as specified in "6.3.1 Tensile strength and elongation (ISO method)" of JIS L1913:2010 "General nonwoven fabric test methods." The average of the two pieces was used as the tensile strength of the artificial leather. The measurements were performed using an Instron single-column tabletop testing machine "3343."

[0169] (16) Abrasion resistance of artificial leather (mg): An abrasion resistance test was conducted on both surfaces of the artificial leather using a James H. Heal & Co. Ltd. "Model 406" abrasion tester and the same company's "Abrastive Cloth SM25" as the standard friction cloth, and the larger value of abrasion weight loss was recorded as the result. In the present invention, a good level is 10 mg or less.

[0170] (17) Texture of artificial leather: The texture of the artificial leather was evaluated by 20 evaluators, 10 healthy adult males and 10 healthy adult females, according to the following evaluation criteria. The texture of the artificial leather was determined to be the most commonly rated. In the case of a tie, the higher rating was designated as the texture of the artificial leather. The good level of the present invention was designated as A or B. A: When held in the hand, it feels very pliable and flexible, and when pulled gently, it feels very stretchy and has a very good texture. B: When held in the hand, it feels pliable and flexible, and when gently pulled, it feels stretchy and has a good texture. C: When held in the hand, it feels lacking in flexibility and pliability, or even when gently pulled, there is no sense of stretch at all, and it has a poor texture.

[0171] (18) Artificial leather feel: The feel of the artificial leather was evaluated by 20 people, 10 healthy adult males and 10 healthy adult females. First, each side of the artificial leather was evaluated using the following evaluation criteria, and the most common evaluation was determined as the feel of that surface. In the case of a tie, the higher evaluation was determined as the feel of that surface. Then, the lowest evaluation of the feel of the both surfaces was determined as the feel of the artificial leather. The good level of the present invention was determined as A or B. A: The surface is extremely smooth and does not feel sticky at all when stroked. B: The surface is smooth to the touch, with only a slight scratch when stroked. C: The surface feels rough and catches when stroked. D: The surface feels very rough, with a large amount of friction when stroked.

[0172] (19) Surface quality of artificial leather: The surface quality of the artificial leather was evaluated by a total of 20 people, 10 healthy adult males and 10 healthy adult females. First, the following evaluations were performed visually on each side of both surfaces of the artificial leather, and the most common evaluation was determined as the surface quality of that surface. In the case of a tie, the higher evaluation was determined as the surface quality of that surface. Then, the lowest evaluation of the surface quality of both surfaces was determined as the surface quality of that artificial leather. In the present invention, a good level was determined as A or B. A: Very dense and uniform surface quality. B: Dense and uniform surface quality. C: The surface quality is poorly dense and varies greatly. D: The surface quality is very poorly dense and varies greatly.

[0173] [Example 1] <Process for producing ultrafine fiber-developing fibers> Ultrafine fiber-forming fibers having an island-in-sea composite structure consisting of island and sea components were melt-spun under the following conditions. Island component: Polyethylene terephthalate with an intrinsic viscosity (IV value) of 0.73 Sea component: Polystyrene with an MFR (melt flow rate, measured according to the test method specified in ISO 1133:1997, the same applies below) of 65g / 10min Spinneret: Spinneret for islands-in-sea composite fiber with 36 islands / hole Spinning temperature: 285℃ Island / sea mass ratio: 55 / 45 Discharge rate: 1.0g / min (hole) Spinning speed: 1100m / min.

[0174] The ultrafine fiber-forming fibers were then stretched 3.4 times in a spinning oil bath at 90°C. They were then crimped using a push-type crimper and cut to a length of 51 mm to obtain raw islands-in-sea composite fibers with a single fiber fineness of 3.2 dtex. The ultrafine fibers obtained from these islands-in-sea composite fibers had an average single fiber diameter of 2.90 μm and a tensile strength of 3.5 cN / dtex.

[0175] <Fabric manufacturing process> (Manufacturing of weft fibers) Polyethylene terephthalate (PET) with an intrinsic viscosity (IV) of 0.78 and PET with an intrinsic viscosity (IV) of 0.51 were melted separately and extruded at a spinning temperature of 295°C through a 12-hole composite spinneret in a composite ratio (wt%) of 50:50, and taken up at a spinning speed of 1450 m / min to obtain a 12-filament side-by-side composite structure undrawn yarn.Furthermore, this was drawn at a draw ratio of 2.6 times using a hot roll-hot plate system drawing machine to obtain a 56 dtex, 12-filament drawn yarn.

[0176] (Manufacturing of warp fibers) PET with an intrinsic viscosity (IV) of 0.65 was extruded from a 72-hole spinneret at a spinning temperature of 295°C and taken up at a spinning speed of 1650 m / min to obtain an undrawn yarn with 72 filaments. This was then drawn at a draw ratio of 2.8 times using a hot roll-hot plate drawing machine to obtain a drawn yarn with 84 dtex and 72 filaments.

[0177] (Fabric manufacturing) A plain weave fabric was produced using a twisted yarn made by twisting the weft fiber 1,500 times / m (twist coefficient 11,200) as the weft yarn and a twisted yarn made by twisting the weft fiber 2,500 times / m (twist coefficient 22,900) as the warp yarn.

[0178] <Step of forming entangled sheet> The raw cotton of the islands-in-sea composite fiber obtained as described above was then subjected to carding and cross-lapping processes to form a laminated web. The woven fabric obtained in the <Fabric Manufacturing Process> was laminated on one side of this laminated web, and needle-punched under the conditions of Table 1 to obtain a nonwoven fabric α having an apparent density of 0.21 g / cm3, in which the woven fabric and the nonwoven fabric α were laminated and integrated. 3 An entangled sheet of 1000 .mu.m was obtained.

[0179] <Step of forming nonwoven fabric β> Furthermore, the raw cotton of the islands-in-sea composite fiber obtained in the above-mentioned <Process for producing ultrafine fiber development type fiber> was used to form a laminated web through carding and cross-lapping processes. This laminated web was needle-punched under the conditions in Table 1 to produce a laminated web having an apparent density of 0.11 g / cm3 in which the ultrafine fiber development type fiber was entangled. 3 A nonwoven fabric β was obtained.

[0180] At this time, the apparent density of the entangled sheet is V A and the apparent density of the nonwoven fabric β: V β3 Ratio of V β3 / V A was 0.52.

[0181] <Step of forming precursor sheet> The entangled sheet and nonwoven fabric β obtained above were laminated together so that the woven or knitted fabric was sandwiched between the nonwoven fabric α and the nonwoven fabric β, and needle punching was performed under the conditions shown in Table 1 to obtain a laminate in which the entangled sheet and nonwoven fabric β were entangled and integrated, with an apparent density of 0.24 g / cm 3 , basis weight 696g / m 2 A precursor sheet having a thickness of 2.9 mm was obtained.

[0182] <Step of forming a water-soluble resin-coated sheet> The precursor sheet obtained as described above was shrunk in hot water at 96°C. The precursor sheet, which had been shrunk in hot water, was then impregnated with an aqueous solution of polyvinyl alcohol (hereinafter sometimes abbreviated as PVA) with a saponification degree of 88% (containing 0.13% by mass of polyethylene glycol relative to the mass of PVA), adjusted to a concentration of 12% by mass. The sheet was then squeezed with a roll and dried for 10 minutes with hot air at 120°C, forming a water-soluble resin-coated sheet in which 32.0% by mass of PVA was added relative to the mass of the precursor sheet, which consisted of a nonwoven fabric and woven / knitted fabric composed of ultrafine fiber-developing fibers.

[0183] <Step of forming a sheet with elastic polymer> The water-soluble resin-coated sheet obtained as described above was immersed in a DMF (dimethylformamide) solution of polyurethane, the polymer diol of which was a polycarbonate-based diol, prepared so that the solids concentration of the polymer elastomer, primarily composed of polyurethane, was 10.0%. The water-soluble resin-coated sheet immersed in the polyurethane DMF solution was then squeezed with a roll. The sheet was then immersed in a 30% by weight DMF aqueous solution to coagulate the polyurethane. At this point, the amount of polymer elastomer applied relative to the weight of the water-soluble resin-coated sheet was 5.0% by weight. The PVA and DMF were then removed with hot water at 95°C, and the sheet was dried with hot air at 100°C for 10 minutes. This resulted in a 1.9 mm-thick polymer elastomer-coated sheet.

[0184] <Process for forming ultrafine fiber sheet> The obtained sheet with elastic polymer was immersed in trichloroethylene and squeezed with a mangle and compressed 10 times, thereby dissolving and removing the sea portion of the ultrafine fiber-producing fiber and compressing the sheet, forming an ultrafine fiber sheet with a thickness of 1.7 mm and containing ultrafine fibers with an average single fiber diameter of 2.90 μm.

[0185] <Step of forming the raised sheet> The ultrafine fiber sheet obtained as described above was ground in three stages using endless sandpaper with a grit size of 180 as the grinding means, with the sheet conveying speed set to 8 m / min and the grinding speed set to 800 m / min. The surface layers on both surfaces were ground by 0.2 mm each, and a raised treatment was performed, resulting in an ultrafine fiber sheet with an average single fiber diameter of 2.90 μm and a basis weight of 324 g / m. 2 A raised sheet having a thickness of 1.3 mm was obtained.

[0186] <Dyeing process of the raised sheet> The raised sheet was dyed at 120°C in a jet dyeing machine, and simultaneously crimping the weft yarn of the woven or knitted fabric. After that, the sheet was reduced and washed to obtain a dyed sheet. After that, it was dried in a pin tenter at 100°C for 7 minutes, and the thickness was 1.7 mm and the basis weight was 399 g / m. 3An artificial leather having a mass ratio of the polymer elastomer of 9.3 mass % was obtained.

[0187] The resulting artificial leather felt supple and flexible, had excellent elasticity, a very smooth feel, a very dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 1 and 2.

[0188] [Example 2] <Process for producing ultrafine fiber-developing fibers> Ultrafine fiber-forming fibers having an island-in-sea composite structure consisting of island and sea components were melt-spun under the following conditions. Island component: Polyethylene terephthalate with an intrinsic viscosity (IV value) of 0.73 Sea component: Polystyrene with an MFR (melt flow rate, measured according to the test method specified in ISO 1133:1997, the same applies below) of 65g / 10min Spinneret: Spinneret for islands-in-sea composite fiber with 36 islands / hole Spinning temperature: 285℃ Island / sea mass ratio: 80 / 20 Discharge rate: 1.2g / min (hole) Spinning speed: 1100m / min.

[0189] The ultrafine fiber-forming fibers were then stretched 3.4 times in a spinning oil bath at 90°C. They were then crimped using a push-in crimper and cut to a length of 51 mm to obtain raw islands-in-sea composite fibers with a single fiber fineness of 4.2 dtex. The ultrafine fibers obtained from these islands-in-sea composite fibers had an average single fiber diameter of 4.40 μm and a tensile strength of 3.7 cN / dtex.

[0190] An artificial leather was obtained in the same manner as in Example 1, except that the <step of producing ultrafine fiber-developing fibers> was changed as described above.

[0191] The resulting artificial leather felt supple and flexible, had excellent elasticity, a very smooth feel, a dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 1 and 2.

[0192] [Example 3] In the <step of forming a water-soluble resin-coated sheet>, as shown in Table 1, an artificial leather was obtained in the same manner as in Example 1, except that 20.0 mass% of PVA was added to the precursor sheet consisting of a nonwoven fabric and a woven or knitted fabric made of ultrafine fiber-developing fibers.

[0193] The resulting artificial leather felt supple and flexible, had excellent elasticity, a smooth feel, a very dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 1 and 2.

[0194] [Example 4] <Process for producing ultrafine fiber-developing fibers> Ultrafine fiber-forming fibers having an island-in-sea composite structure consisting of island and sea components were melt-spun under the following conditions. Island component: Polyethylene terephthalate with an intrinsic viscosity (IV value) of 0.73 Sea component: Polystyrene with an MFR (melt flow rate, measured according to the test method specified in ISO 1133:1997, the same applies below) of 65g / 10min Spinneret: Spinneret for islands-in-sea composite fiber with 36 islands / hole Spinning temperature: 285℃ Island / sea mass ratio: 80 / 20 Discharge rate: 1.2g / min (hole) Spinning speed: 1100m / min.

[0195] The ultrafine fiber-forming fibers were then stretched 3.4 times in a spinning oil bath at 90°C. They were then crimped using a push-in crimper and cut to a length of 51 mm to obtain raw islands-in-sea composite fibers with a single fiber fineness of 4.2 dtex. The ultrafine fibers obtained from these islands-in-sea composite fibers had an average single fiber diameter of 4.40 μm and a tensile strength of 3.7 cN / dtex.

[0196] An artificial leather was obtained in the same manner as in Example 1, except that the <step of producing ultrafine fiber-developing fiber> was changed as described above, and in the <step of forming a water-soluble resin-coated sheet>, as shown in Table 1, 52.0 mass% of PVA was added relative to the mass of the precursor sheet consisting of a nonwoven fabric and a woven or knitted fabric made of ultrafine fiber-developing fiber.

[0197] The resulting artificial leather felt supple and flexible, had excellent elasticity, a smooth feel, a dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 1 and 2.

[0198] [Example 5] An artificial leather was obtained in the same manner as in Example 1, except that in the <step of forming a polymeric elastomer-attached sheet>, the amount of polymeric elastomer added was 3.0 mass % relative to the mass of the water-soluble resin-attached sheet.

[0199] The resulting artificial leather felt supple and flexible, had excellent elasticity, a very smooth feel, a very dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 1 and 2.

[0200] [Example 6] <Process for producing ultrafine fiber-developing fibers> Ultrafine fiber-forming fibers having an island-in-sea composite structure consisting of island and sea components were melt-spun under the following conditions. Island component: Polyethylene terephthalate with an intrinsic viscosity (IV value) of 0.73 Sea component: Polystyrene with an MFR (melt flow rate, measured according to the test method specified in ISO 1133:1997, the same applies below) of 65g / 10min Spinneret: Spinneret for islands-in-sea composite fiber with 36 islands / hole Spinning temperature: 285℃ Island / sea mass ratio: 80 / 20 Discharge rate: 1.2g / min (hole) Spinning speed: 1100m / min.

[0201] The ultrafine fiber-forming fibers were then stretched 3.4 times in a spinning oil bath at 90°C. They were then crimped using a push-in crimper and cut to a length of 51 mm to obtain raw islands-in-sea composite fibers with a single fiber fineness of 4.2 dtex. The ultrafine fibers obtained from these islands-in-sea composite fibers had an average single fiber diameter of 4.40 μm and a tensile strength of 3.7 cN / dtex.

[0202] An artificial leather was obtained in the same manner as in Example 1, except that the <step of producing ultrafine fiber-developing fiber> was changed as described above, and that in the <step of forming a water-soluble resin-coated sheet>, as shown in Table 1, 26.0 mass% of PVA was added relative to the mass of the precursor sheet consisting of a nonwoven fabric and a woven or knitted fabric made of ultrafine fiber-developing fiber.

[0203] The resulting artificial leather felt supple and flexible, had excellent elasticity, a very smooth feel, a very dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 1 and 2.

[0204] [Example 7] <Process for producing ultrafine fiber-forming fibers> Ultrafine fiber-forming fibers having an island-in-sea composite structure consisting of island and sea components were melt-spun under the following conditions. Island component: Polyethylene terephthalate with an intrinsic viscosity (IV value) of 0.73 Sea component: Polystyrene with an MFR (melt flow rate, measured according to the test method specified in ISO 1133:1997, the same applies below) of 65g / 10min Spinneret: Spinneret for islands-in-sea composite fiber with 36 islands / hole Spinning temperature: 285℃ Island / sea mass ratio: 80 / 20 Discharge rate: 1.2g / min (hole) Spinning speed: 1100m / min.

[0205] The ultrafine fiber-forming fibers were then stretched 3.4 times in a spinning oil bath at 90°C. They were then crimped using a push-in crimper and cut to a length of 51 mm to obtain raw islands-in-sea composite fibers with a single fiber fineness of 4.2 dtex. The ultrafine fibers obtained from these islands-in-sea composite fibers had an average single fiber diameter of 4.40 μm and a tensile strength of 3.7 cN / dtex.

[0206] An artificial leather was obtained in the same manner as in Example 1, except that the <step of producing ultrafine fiber-developing fiber> was changed as described above, and in the <step of forming a water-soluble resin-coated sheet>, 26.0 mass% of PVA was added relative to the mass of the precursor sheet consisting of a nonwoven fabric and a woven or knitted fabric made of ultrafine fiber-developing fiber, as shown in Table 1, and in the <step of forming a polymer elastomer-coated sheet>, the amount of polymer elastomer added relative to the mass of the water-soluble resin-coated sheet was 21.0 mass%.

[0207] The resulting artificial leather felt supple and flexible, had a good texture with good stretchability, a smooth feel, a dense feel, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 1 and 2.

[0208] [Example 8] As shown in Table 1, in the <process of forming an entangled sheet>, the needle punch density from each surface of the entangled sheet is set to (D a1 , D a2 ) to adjust the total needle punch density (D a1 +D a2) was set to half of that in Example 1, and in the <step of forming nonwoven fabric β>, the needle punch density (D b1 , D b2 ) to adjust the total needle punch density (D b1 +D b2 An artificial leather was obtained in the same manner as in Example 1, except that the thickness of the leather was half that of Example 1.

[0209] The resulting artificial leather felt supple and flexible, had excellent elasticity, a very smooth feel, a very dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 3 and 4.

[0210] [Example 9] As shown in Table 1, in the <process of forming an entangled sheet>, the needle punch density (D a1 , D a2 ) to adjust the total needle punch density (D a1 +D a2 ) was set to half of that in Example 1, and in the <step of forming nonwoven fabric β>, the needle punch density (D b1 , D b2 ) to adjust the total needle punch density (D b1 +D b2 An artificial leather was obtained in the same manner as in Example 1, except that the amount of polymer elastomer added relative to the mass of the water-soluble resin-attached sheet in the <step of forming a polymer elastomer-attached sheet> was 11.0 mass%.

[0211] The resulting artificial leather felt supple and flexible, had a good texture with good stretchability, a smooth feel, a dense feel, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 3 and 4.

[0212] [Example 10] As shown in Table 1, in the <process of forming an entangled sheet>, the needle punch density (counts / cm ) from the side where the woven or knitted fabric is laminated is 2 ):D a1 and the needle punch density (counts / cm) from the side where the woven / knitted fabric is laminated and the opposite side. 2 ):D a2 Ratio of D a1 / D a2 An artificial leather was obtained in the same manner as in Example 1, except that the value of the tensile strength was set to 0.25.

[0213] The resulting artificial leather felt supple and flexible, had excellent elasticity, a very smooth feel, a very dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 3 and 4.

[0214] [Example 11] As shown in Table 1, in the <process of forming an entangled sheet>, the needle punch density (counts / cm ) from the side where the woven or knitted fabric is laminated is 2 ):D a1 and the needle punch density (counts / cm) from the side where the woven / knitted fabric is laminated and the opposite side. 2 ):D a2 Ratio of D a1 / D a2 In the step of forming the nonwoven fabric β, the needle punch density (counts / cm ) from the surface side on which the woven or knitted fabric is laminated is set to 0.25. 2 ):D b1 and the needle punch density (numbers / cm) from the surface side of the precursor sheet. 2 ):D b2 Ratio of D b1 / D b2 An artificial leather was obtained in the same manner as in Example 1, except that the value of the tensile strength was set to 0.18.

[0215] The resulting artificial leather felt supple and flexible, had excellent elasticity, a smooth feel, a dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 3 and 4.

[0216] [Example 12] As shown in Table 1, in the <process of forming an entangled sheet>, the needle punch density (D a1 , D a2 ) to adjust the total needle punch density (D a1 +D a2 ) was set to half of that in Example 1, and in the <step of forming nonwoven fabric β>, the needle punch density (D b1 , D b2 ) to adjust the total needle punch density (D b1 +D b2 ) was set to half of that in Example 1, and the needle punch density (counts / cm 2 ) from the surface side on which the woven or knitted fabric was laminated was set to 2 ):D b1 and the needle punch density (numbers / cm) from the surface side of the precursor sheet. 2 ):D b2 Ratio of D b1 / D b2 An artificial leather was obtained in the same manner as in Example 1, except that the value of the elastic modulus was set to 0.67.

[0217] The resulting artificial leather felt supple and flexible, had excellent elasticity, a very smooth feel, a very dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 3 and 4.

[0218] [Example 13] As shown in Table 1, in the <process of forming an entangled sheet>, the needle punch density (D a1 , D a2 ) to adjust the total needle punch density (D a1 +D a2 ) was set to half of that in Example 1, and the needle punch density (counts / cm 2 ):D a1 and the needle punch density (counts / cm) from the side where the woven / knitted fabric is laminated and the opposite side. 2 ):D a2 Ratio of D a1 / D a2The density of needle punches punched from each surface of the nonwoven fabric β in the process of forming the nonwoven fabric β (D b1 , D b2 ) to adjust the total needle punch density (D b1 +D b2 ) was set to half of that in Example 1, and when the nonwoven fabric β was laminated with the entangled sheet, the needle punch density (counts / cm ) from the surface side that would become the woven or knitted fabric side was set to 2 ):D b1 and the needle punch density (numbers / cm) from the surface side of the precursor sheet. 2 ):D b2 Ratio of D b1 / D b2 An artificial leather was obtained in the same manner as in Example 1, except that the value of the elastic modulus was set to 0.67.

[0219] The resulting artificial leather felt supple and flexible, had excellent elasticity, a smooth feel, a dense texture, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 3 and 4.

[0220] [Example 14] As shown in Table 1, in the <process of forming an entangled sheet>, the needle punch density (D a1 , D a2 ) to adjust the total needle punch density (D a1 +D a2 ) was set to 1.5 times that of Example 1, and in the <step of forming nonwoven fabric β>, the needle punch density (D b1 , D b2 ) to adjust the total needle punch density (D b1 +D b2 An artificial leather was obtained in the same manner as in Example 1, except that the amount of the cellulose ester compound was 1.5 times that of Example 1.

[0221] The resulting artificial leather felt supple and flexible, had a good texture with good stretchability, a smooth feel, a dense feel, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 3 and 4.

[0222] [Example 15] As shown in Table 1, in the <process of forming an entangled sheet>, the needle punch density (D a1 , D a2 ) to adjust the total needle punch density (D a1 +D a2 ) was set to half of that in Example 1, and in the <step of forming nonwoven fabric β>, the needle punch density (D b1 , D b2 ) to adjust the total needle punch density (D b1 +D b2 ) was set to half of that in Example 1, and in the <step of forming a precursor sheet>, the basis weight was set to 1221 g / m 2 An artificial leather was obtained in the same manner as in Example 1, except that the amount of raw cotton was adjusted so as to be:

[0223] The resulting artificial leather felt supple and flexible, had a good texture with good stretchability, a smooth feel, a dense feel, a uniform surface quality, and excellent abrasion resistance. The results are shown in Tables 3 and 4.

[0224] [Table 1]

[0225] [Table 2]

[0226] [Table 3]

[0227] [Table 4]

[0228] [Comparative Example 1] As shown in Table 5, in the <process of forming an entangled sheet>, the needle punch density (D a1 , D a2 ) to adjust the total needle punch density (D a1 +D a2 An artificial leather was obtained in the same manner as in Example 1, except that the thickness of the leather was half that of Example 1.

[0229] The resulting artificial leather had a smooth feel, a dense texture, a uniform surface quality, and excellent abrasion resistance, but it lacked suppleness and flexibility, and had no sense of stretch, resulting in a poor texture. The results are shown in Tables 5 and 6.

[0230] Comparative Example 2 As shown in Table 5, in the <process of forming an entangled sheet>, the needle punch density (D a1 , D a2 ) to adjust the total needle punch density (D a1 +D a2 ) was set to 1.5 times that of Example 1, and in the <step of forming nonwoven fabric β>, the needle punch density (D b1 , D b2 ) to adjust the total needle punch density (D b1 +D b2 An artificial leather was obtained in the same manner as in Example 1, except that the thickness of the leather was half that of Example 1.

[0231] The artificial leather obtained had a very smooth feel and excellent abrasion resistance, but it lacked suppleness and flexibility, had no sense of stretch, had a poor texture, lacked denseness, and had widely varying surface quality. The results are shown in Tables 5 and 6.

[0232] Comparative Example 3 As shown in Table 5, in the <process of forming an entangled sheet>, the needle punch density (counts / cm ) from the side where the woven or knitted fabric is laminated is 2 ):D a1 and the needle punch density (counts / cm) from the side where the woven / knitted fabric is laminated and the opposite side. 2 ):D a2 Ratio of D a1 / D a2 An artificial leather was obtained in the same manner as in Example 1, except that the value of the tensile strength was set to 0.07.

[0233] The resulting artificial leather had a very smooth feel, a very dense feel, a uniform surface quality, and excellent abrasion resistance, but it lacked suppleness and flexibility, and had no sense of stretch at all, resulting in a poor texture. The results are shown in Tables 5 and 6.

[0234] Comparative Example 4 As shown in Table 5, in the process of forming nonwoven fabric β, the needle punch density (counts / cm ) from the surface side, which is the side on which the woven or knitted fabric is laminated, is 2 ):D b1 and the needle punch density (numbers / cm) from the surface side of the precursor sheet. 2 ):D b2 Ratio of D b1 / D b2 An artificial leather was obtained in the same manner as in Example 1, except that the value of the tensile strength was set to 0.11.

[0235] The resulting artificial leather had a very smooth feel, a very dense feel, a uniform surface quality, and excellent abrasion resistance, but it lacked suppleness and flexibility, and had no sense of stretch at all, resulting in a poor texture. The results are shown in Tables 5 and 6.

[0236] Comparative Example 5 As shown in Table 5, in the <precursor sheet forming step>, the needle punch density (numbers / cm 2 ):D A and the needle punch density (counts / cm 2 ):D β Ratio of D A / D βAn artificial leather was obtained in the same manner as in Example 1, except that the value of the tensile strength was set to 0.25.

[0237] The resulting artificial leather had excellent abrasion resistance, but was poor in suppleness and flexibility, had no sense of stretch, had a poor texture, felt very rough to the touch, was very lacking in denseness, and had widely varying surface quality. The results are shown in Tables 5 and 6.

[0238] Comparative Example 6 As shown in Table 5, in the <precursor sheet forming step>, the needle punch density (numbers / cm 2 ):D A and the needle punch density (counts / cm 2 ):D β Ratio of D A / D β An artificial leather was obtained in the same manner as in Example 1, except that the value of the tensile strength was set to 0.88.

[0239] The resulting artificial leather had excellent abrasion resistance, but was poor in suppleness and flexibility, had no sense of stretch, had a poor texture, felt rough to the touch, lacked denseness, and had widely varying surface quality. The results are shown in Tables 5 and 6.

[0240] Comparative Example 7 As shown in Table 5, in the <process of forming an entangled sheet>, the needle punch density (counts / cm ) from the side where the woven or knitted fabric is laminated is 2 ):D a1 and the needle punch density (counts / cm) from the side where the woven / knitted fabric is laminated and the opposite side. 2 ):D a2 Ratio of D a1 / D a2 An artificial leather was obtained in the same manner as in Example 1, except that the value of the tensile strength was set to 1.00.

[0241] The resulting artificial leather had a very smooth feel, a very dense feel, a uniform surface quality, and excellent abrasion resistance, but it lacked suppleness and flexibility, and had no sense of stretch at all, resulting in a poor texture. The results are shown in Tables 5 and 6.

[0242] [Comparative Example 8] As shown in Table 5, in the process of forming nonwoven fabric β, the needle punch density (counts / cm ) from the surface side, which is the side on which the woven or knitted fabric is laminated, is 2 ):D b1 and the needle punch density (numbers / cm) from the surface side of the precursor sheet. 2 ):D b2 Ratio of D b1 / D b2 An artificial leather was obtained in the same manner as in Example 1, except that the value of the tensile strength was set to 1.00.

[0243] The resulting artificial leather had a very smooth feel, a very dense feel, a uniform surface quality, and excellent abrasion resistance, but it lacked suppleness and flexibility, and had no sense of stretch at all, resulting in a poor texture. The results are shown in Tables 5 and 6.

[0244] Comparative Example 9 As shown in Table 5, in the <process of forming an entangled sheet>, the needle punch density (counts / cm ) from the side where the woven or knitted fabric is laminated is 2 ):D a1 and the needle punch density (counts / cm) from the side where the woven / knitted fabric is laminated and the opposite side. 2 ):D a2 Ratio of D a1 / D a2 In the process of forming nonwoven fabric β, the needle punch density (counts / cm ) from the surface side, which is the side on which the woven or knitted fabric is laminated, is set to 0.41. 2 ):D b1 and the needle punch density (numbers / cm) from the surface side of the precursor sheet. 2 ):D b2 Ratio of D b1 / D b2 In the precursor sheet forming step, the weight is 1221 g / m 2 An artificial leather was obtained in the same manner as in Example 1, except that the amount of raw cotton was adjusted so as to be:

[0245] The artificial leather obtained was supple and flexible, had a good stretchy texture, and was excellent in abrasion resistance, but had a rough feel, very little denseness, and a surface quality that varied widely. The results are shown in Tables 5 and 6.

[0246] [Table 5]

[0247] [Table 6]

[0248] As shown in Tables 1 to 4, the artificial leathers of Examples 1 to 15 comprised a fiber-entangled body including a nonwoven fabric composed of ultrafine fibers having an average single fiber diameter within a predetermined range and a woven or knitted fabric composed of crimped fibers, and a polymeric elastomer, and both surfaces had nap. In the step of forming the entangled sheet, the apparent density distribution in the thickness direction of nonwoven fabric α was set within a predetermined range, and prior to the step of forming the precursor sheet, the apparent density distribution in the thickness direction of nonwoven fabric β was set within a predetermined range. The ratio of the apparent densities of the entangled sheet and nonwoven fabric β was also set within a predetermined range. Furthermore, in the step of forming the precursor sheet, the ratio of the needle-punch density driven from the entangled sheet side to the needle-punch density driven from the nonwoven fabric β side was set within a predetermined range, thereby ensuring that the thickness of each nonwoven fabric in the artificial leather was within a predetermined range. In addition, in the cross section of the artificial leather, the area excluding the napped portion from the nonwoven fabric portion was divided into three equal parts in the thickness direction, and the ratio of the area percentage of the polymer elastomer in the nap-most portion to the area percentage of the polymer elastomer in the woven / knitted fabric portion was within a predetermined range. Due to these configurations, the artificial leathers of Examples 1 to 15 had an elegant surface appearance on both surfaces and were highly stretchable despite their thickness.

[0249] On the other hand, as shown in Tables 5 and 6, the artificial leathers of Comparative Examples 1 and 2 had an apparent density ratio of the entangled sheet to the nonwoven fabric β outside the specified range, which resulted in the thickness of the nonwoven fabric being outside the specified range, or the area ratio of the polymeric elastomer in the region of the nonwoven fabric excluding the napped portion in the cross section of the artificial leather being outside the specified range. Therefore, the artificial leathers did not have high stretchability despite their thickness, and it was not possible to achieve an elegant surface appearance on both surfaces.

[0250] In the artificial leather of Comparative Example 3, the apparent density distribution in the thickness direction of nonwoven fabric α was outside the predetermined range in the step of forming the entangled sheet, and as a result, the area ratio of the polymer elastomer in the region excluding the napped portion of the nonwoven fabric in the cross section of the artificial leather was outside the predetermined range. In the artificial leather of Comparative Example 4, the apparent density distribution in the thickness direction of nonwoven fabric β was outside the predetermined range in the step of forming nonwoven fabric β, and as a result, the area ratio of the polymer elastomer in the region excluding the napped portion of the nonwoven fabric in the cross section of the artificial leather was outside the predetermined range. As a result, in Comparative Examples 3 and 4, although an elegant surface appearance was achieved on both surfaces, it was not possible to obtain artificial leathers that were thick yet highly stretchable.

[0251] In addition, in the artificial leathers of Comparative Examples 5 and 6, in the precursor sheet formation process, the ratio of the needle punch density from the entangled sheet side to the needle punch density from the nonwoven fabric β side was outside the specified range, resulting in a nonwoven fabric thickness outside the specified range, making it impossible to produce artificial leather that was thick yet highly stretchable, and also making it impossible to achieve an elegant surface appearance on both surfaces.

[0252] In the artificial leather of Comparative Example 7, the apparent density distribution in the thickness direction of nonwoven fabric α was outside the predetermined range in the step of forming the entangled sheet, and as a result, the area ratio of the polymer elastomer in the region excluding the napped portion of the nonwoven fabric in the cross section of the artificial leather was outside the predetermined range. In the artificial leather of Comparative Example 8, the apparent density distribution in the thickness direction of nonwoven fabric β was outside the predetermined range in the step of forming nonwoven fabric β, and as a result, the area ratio of the polymer elastomer in the region excluding the napped portion of the nonwoven fabric in the cross section of the artificial leather was outside the predetermined range. As a result, in Comparative Examples 7 and 8, although an elegant surface appearance was achieved on both surfaces, it was not possible to obtain artificial leathers that were thick yet highly stretchable.

[0253] In addition, in the artificial leather of Comparative Example 9, the distribution of apparent density in the thickness direction of nonwoven fabric α was outside the specified range in the process of forming the entangled sheet, and the distribution of apparent density in the thickness direction of nonwoven fabric β was outside the specified range in the process of forming nonwoven fabric β. As a result, the area ratio of the polymer elastomer in the region excluding the napped portion of the nonwoven fabric portion in the cross section of the artificial leather was outside the specified range, and although an artificial leather having high elasticity despite its thickness could be obtained, an elegant surface appearance could not be achieved on both surfaces. [Industrial Applicability]

[0254] The artificial leather of the present invention can be used in a wide range of applications, such as automobile interior materials, furniture, miscellaneous goods, and clothing. However, since it has an elegant surface appearance on both surfaces and high stretchability despite its large thickness, it is particularly suitable for use in clothing and miscellaneous goods. [Explanation of symbols]

[0255] 1:Artificial leather 2: Pierrection part 3: Base part 4: Woven and knitted fabrics

Claims

1. a nonwoven fabric composed of ultrafine fibers having an average single fiber diameter of 0.01 μm or more and 10.00 μm or less; A woven or knitted fabric composed of crimped fibers; A fiber-entangled body comprising: A polymeric elastomer; An artificial leather having both surfaces with raised nap, The fiber-entangled body is formed by laminating the nonwoven fabric, the woven or knitted fabric, and the nonwoven fabric in this order, The nonwoven fabrics each have a thickness of 0.4 mm or more and 2.0 mm or less, and the cross section of the artificial leather satisfies the following formula 1. 1.2≦R １ / R ２ ≦2.0 ・・・(Formula 1) where: R １ : Area ratio (%) of the polymer elastomer in the most napped part of the cross section of the artificial leather, obtained by dividing the area of ​​the nonwoven fabric excluding the napped part into three equal parts in the thickness direction R ２ : Area ratio (%) of the polymer elastomer in the part closest to the woven or knitted fabric in the cross section of the artificial leather, which is obtained by dividing the area of ​​the nonwoven fabric excluding the napped part into three equal parts in the thickness direction

2. 2. The artificial leather according to claim 1, wherein the area ratio of the polymeric elastomer to the entire cross section of the artificial leather is 0.1% or more and 10.0% or less.

3. 3. The artificial leather according to claim 1, wherein the area ratio of the polymeric elastomer measured from the surface of the artificial leather is 0.01% or more and 3.00% or less on both surfaces.

4. 3. The artificial leather according to claim 1, wherein the average nap length of at least one surface of the artificial leather is 200 μm or more and 600 μm or less.

5. a nonwoven fabric composed of ultrafine fibers having an average single fiber diameter of 0.01 μm or more and 10.00 μm or less; A woven or knitted fabric composed of crimped fibers; A fiber-entangled body comprising: A polymeric elastomer; A method for producing artificial leather having raised nap on both surfaces, a step of entangling a woven or knitted fabric on one side of nonwoven fabric α made of ultrafine fiber-developing fibers to form an entangled sheet; A step of forming a nonwoven fabric β made of ultrafine fiber development type fibers; a step of laminating the entangled sheet and the nonwoven fabric β so that the woven or knitted fabric is sandwiched between the nonwoven fabric α and the nonwoven fabric β, and entangled and integrated by needle punching to form a precursor sheet; applying a water-soluble resin to the precursor sheet to form a water-soluble resin-coated sheet; a step of providing a polymeric elastomer to the water-soluble resin-coated sheet to form a polymeric elastomer-coated sheet; generating the ultrafine fibers from the ultrafine fiber-producing fibers in the polymeric elastomer-attached sheet to form an ultrafine fiber sheet; grinding both surfaces of the ultrafine fiber sheet to form a raised sheet; and The entangled sheet satisfies the following formula 2: In the step of forming the precursor sheet, The nonwoven fabric β before the entanglement and integration satisfies the following formula 3, The entangled sheet and the nonwoven fabric β before being entangled and integrated satisfy the following formula 4: The entanglement and integration satisfies the following formula 5: A method for manufacturing artificial leather. 0.50≦V Ａ１ / V Ａ２ ≦0.80 ・・・(Formula 2) 0.50≦V β１ / V β２ ≦0.80 ・・・(Formula 3) 0.30≦V β３ / V Ａ ≦0.80 ・・・(Formula 4) 0.30≦D A / D β ≦0.70 ・・・(Formula 5) where: V Ａ１ Apparent density (g / cm) of the nonwoven fabric α in the region containing the woven or knitted fabric on the surface of one of two regions obtained by dividing the cross section of the entangled sheet into two equal regions in the thickness direction ３ ) V Ａ２ : Apparent density (g / cm) of nonwoven fabric α in the region containing nonwoven fabric α on the surface of two regions obtained by dividing the cross section of the entangled sheet into two equal parts in the thickness direction ３ ) V β１ : Apparent density (g / cm 3 ) of the nonwoven fabric β in the cross section of the nonwoven fabric β before the entanglement and integration, in a region divided equally in the thickness direction, at a portion corresponding to the woven / knitted fabric side ３ ) V β２ : Apparent density (g / cm) of the nonwoven fabric β in a region that is not on the woven / knitted fabric side in a region that is equally divided in the thickness direction in the cross section of the nonwoven fabric β before the entanglement and integration ３ ) V Ａ : Apparent density (g / cm) of the entangled sheet before entanglement and integration ３ ) V β３ : Apparent density (g / cm ) of the nonwoven fabric β before the entanglement and integration ３ ) D Ａ : Needle punch density (numbers / cm) punched from the entangled sheet side ３ ) D β : Needle punch density (number / cm) punched from the β side of the nonwoven fabric ３ )

6. The V Ａ and the V β３ However, both are 0.01 g / cm ３ 0.30g / cm or more ３ The method for producing an artificial leather according to claim 5, wherein:

7. The method for producing an artificial leather according to claim 5 or 6, wherein in the step of forming the water-soluble resin-applied sheet, the water-soluble resin is applied in an amount of 25% by mass or more and 50% by mass or less relative to the mass of the precursor sheet.

8. 7. The method for producing an artificial leather according to claim 5, wherein in the step of forming the polymeric elastomer-attached sheet, the polymeric elastomer is applied in an amount of 4% by mass to 20% by mass relative to the mass of the water-soluble resin-attached sheet.

9. A garment comprising the artificial leather according to claim 1 or 2.

10. Miscellaneous goods comprising the artificial leather according to claim 1 or 2.

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