Artificial leather and method for producing the same

Abstract

To provide a recyclable artificial leather having a set of good feeling, high abrasion resistance, and high-class feeling appearance, and a production method of the same.SOLUTION: An artificial leather at least includes a surface fiber layer constituting a first surface, where (1) the surface fiber layer includes a main fiber, and a thermoplastic resin, (2) the fineness of the main fiber is 0.01 dtex or more and 0.5 dtex or less, (3) at least one part of the thermoplastic resin bonds between the main fibers, (4) the number average volume of the thermoplastic resin in the surface fiber layer is 3,500 μm3 or more and 24,000 μm3 or less, and (5) the thermoplastic resin is a copolymer of polyester and aliphatic polyether. A production method of the same is also provided.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to artificial leather and a method for manufacturing the same.

Background Art

[0002] Artificial leather is widely accepted in the market as a substitute material for natural leather. It can achieve various product developments such as silver surface finish and suede finish, can exhibit diverse colors not found in natural leather through the dyeing process, and is easy to maintain. Therefore, it is widely used as a high-functional design material. In particular, suede-like artificial leather with a napped outer surface is suitably used in fields such as shoes, bags, furniture, seat skin materials and interior materials for automobiles, railway vehicles, airplanes, ships, etc., and clothing materials such as ribbons and emblem bases. In these fields, both good appearance quality, supple texture, and resistance to physical loads such as abrasion resistance during long-term use are required.

[0003] According to the definition of JIS-6601, artificial leather is classified into "smooth" with a silver surface appearance of leather and "nap" with an appearance of leather such as nubuck, suede, and velour depending on its appearance. However, the artificial leather of the present embodiment relates to the one classified as "nap" (that is, napped artificial leather having a napped appearance). The napped appearance can be formed by buffing (napping) the outer surface of the main fiber layer (also referred to as the front (omote) surface) with sandpaper or the like. In addition, in this specification, the outer surface of the artificial leather, the outer surface of the main fiber layer, the outer surface of the fiber sheet, and the outer surface of the laminated sheet are the surfaces that are exposed to the outside when used as artificial leather (for example, in the case of chair use, the surface that comes into contact with the human body). In one aspect, in the case of napped artificial leather, the outer surface of the main fiber layer is napped or fluffed by buffing or the like.

[0004] Materials for artificial leather mainly consist of a non-woven fabric structure formed by entangling ultra-fine fibers made of materials such as polyethylene terephthalate and nylon, impregnated and adhered with a polymer elastomer resin including polyurethane. If the fibers are simply physically entangled by needle punching or water jet entanglement methods without impregnating the polymer elastomer resin, problems will occur during actual use, such as insufficient abrasion resistance, lack of the smooth touch of artificial leather, a large amount of yarn shedding during the dyeing process, and manufacturing defects.

[0005] Therefore, in the manufacturing process of artificial leather, a method of imparting good texture and abrasion resistance by attaching a polymer elastomer such as polyurethane is widely used. For example, types of artificial leather impregnated and adhered with polyurethane are commercially available under names such as Alcantara (trademark), Exene (trademark), and Lamous (trademark). However, polymer elastomers such as polyurethane are prone to problems such as high bleed-out property of dyes, poor washing fastness without sufficient reduction washing treatment, susceptibility to ultraviolet rays, easy deterioration with long-term use, resulting in color changes and easy occurrence of deterioration during long-term use. In addition, since it cannot be decomposed under the reaction conditions where polyester depolymerizes, recycling is difficult in a composite system with polyester fibers, which are the most widely used main fibers of artificial leather.

[0006] Patent Document 1 below discloses an example of using polyurethane with a porous structure as an example of a binder for artificial leather. This method can exhibit good quality at the beginning of production, but has drawbacks such as polyurethane deteriorating during long-term use and insufficient abrasion resistance being exhibited. In addition, the material composition becomes a composite system of different chemical materials, namely polyester fibers and a polyurethane binder, and cannot be a single material composition. Therefore, in order to adapt to existing recycling processes such as chemical recycling and material recycling, it is necessary to newly develop a removal process technology for separating polyester and polyurethane, resulting in the problem that recycling becomes difficult.

[0007] In addition to impregnating and adhering a polymer elastomer such as polyurethane, as a means of obtaining a binder effect for imparting strength to artificial leather, a method has been considered in the past of mixing heat-fusible fibers during the production of non-woven fabric for artificial leather and melting them to adhere the main fibers together. For example, in Patent Document 2 below, in its examples, fibers having a thick fiber diameter and being of a sheath-core type are used as the heat-fusible fibers. Since the melting points of the main fibers are connected through the core fibers, the non-woven fabric has a drawback of becoming hard in texture and being inferior in quality.

[0008] Also, in Patent Document 3 below, since the process of heat-shrinking the non-woven fabric is included, the molten mass of the heat-fusible fibers tends to become large, resulting in a drawback of being inferior in surface quality. Furthermore, in order to generate molten fibers from ultrafine fiber-generating composite fibers typified by sea-island type fibers, the molten mass tends to concentrate on the part of the original composite fiber. From this point as well, drawbacks derived from the manufacturing method in which the molten mass tends to become large are likely to occur.

[0009] Also, in Patent Document 4, a leather-like article and a method for manufacturing the same are proposed in which a polyester ultrafine fiber layer and heat-fusible fibers made of a copolymerized polyester having a melting point 10 °C or more lower than that thereof are laminated, and a molding and fusing treatment is performed after a high-speed fluid treatment. The leather article manufactured by this manufacturing method laminates the heat-fusible fiber layer and the polyester fiber layer as separate layers and performs a heat-fusing treatment. In addition, since ultrafine fibers formed from sea-island fibers are used, when evaluating abrasion resistance, the ultrafine fibers tend to become entangled and form pills due to the voids inside the fiber bundles generated from the sea part of the sea-island fibers, and sufficient abrasion resistance cannot be exhibited, and the aging deterioration of the appearance during use is also remarkable.

[0010] In addition, in Patent Document 5 below, in order to provide artificial leather having good texture, high abrasion resistance, and cuttability and shape stability without impregnating a polymer elastomer such as a polyurethane resin, at least the surface fiber layer of a non-woven fabric having a multi-layer structure of at least two or more layers of a surface fiber layer and a scrim layer which is a woven or knitted fabric is mixed with heat-fusible short fibers at a specific ratio and then subjected to a heat-fusing treatment to manufacture artificial leather. Although the obtained artificial leather has improved resistance to artificial sebum because it does not contain a polyurethane resin, in terms of a specific application development such as a car seat application where both high abrasion resistance and a supple texture are required, the abrasion resistance is more than 20,000 times in the abrasion resistance test by the Martindale method, and the texture value is less than 26 cm in the flexibility test, there is still room for improvement.

[0011] In addition, in Patent Document 6 below, in the invention described in Patent Document 5, by exposing a part of the thermoplastic resin formed by melting the heat-fusible short fibers on the surface of the surface fiber layer in a lump state of a predetermined size, the abrasion resistance (more than 40,000 times in the abrasion resistance test by the Martindale method) and the texture (bending value less than 24 cm in the pure bending measurement of KES) are improved. However, similar to Patent Document 5, in terms of a specific application development such as a car seat application where both high abrasion resistance and a supple texture are required, there is still room for improvement.

[0012] Furthermore, Patent Document 7 below also describes that the present invention provides a novel fiber laminate sheet that has a soft surface texture and appropriate firmness, stiffness, and breathability when not impregnated with an elastic polymer, and that the present invention provides a fiber laminate sheet that can be made into artificial leather with a texture closer to that of natural leather when impregnated with an elastic polymer, as well as artificial leather using the same, and synthetic fiber paper used for the same that can easily dissociate and entangle single fibers during hydroentanglement, all at low cost. Therefore, the artificial leather described in Patent Document 7 is limited to one that contains a polymer elastomer such as a water-based polyurethane. Patent Document 7 also describes that the synthetic fiber paper of the present invention is (1) a synthetic fiber paper in which the fibers are weakly bonded together by agglutination, (2) a synthetic fiber paper in which the agglutination is released by the pressure of mechanical entanglement and the fibers are redispersed in the thickness direction to form a three-dimensional entanglement, and (3) a synthetic fiber paper in which the binder short fibers soften, shrink, and deform during heat treatment after entanglement, bonding the entangled points, thereby improving the peel strength between the layers compared to when entangled. In order to achieve the series of actions (1) to (3), the synthetic fiber paper contains polyester short fibers as the main component fiber, and is partially bonded to the main component fiber by weak agglutination at the drying temperature during papermaking (100 to 120°C), and then is heated at a temperature of 150 to 180°C, which is higher than the drying temperature during papermaking, and further softens, shrinks, and has a bond-developing effect. According to these descriptions, the substance that softens and shrinks is the binder short fiber, and therefore Patent Document 7 does not teach that a portion of the thermoplastic resin formed by melting the heat-fusible short fiber is exposed on the surface of the surface fiber layer in the form of lumps of a predetermined size, nor does it state that abrasion resistance or feel is improved.

[0013] Furthermore, Patent Document 8 below describes a non-impregnated base material useful as a base fabric for artificial leather, an artificial leather made therefrom, and a method for producing the same. Also, a polyether ester block copolymer obtained by copolymerizing an elastic polymer with a thermoplastic polyester as a hard segment and a polyalkylene glycol as a soft segment is selected and heat-fused, and the structure of the heat-fused resin is made to cover the main fibers while making a part of the interface in a fused state and the remaining interface portions in a non-contact state, that is, a partially fused portion structure. By doing so, it is disclosed that a non-impregnated base material useful as a base fabric for artificial leather having a leather-like texture, excellent air permeability and elastic recovery ability, and being lightweight with a small amount of binder, and a method for producing the same are provided. However, since the binder is coated on the surface of the composite fiber and the molten mass tends to be large, problems remain in the wear resistance characteristics and the texture.

Prior Art Documents

Patent Documents

[0014]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Summary of the Invention

Problems to be Solved by the Invention

[0015] In view of the above-described prior art level, the problem to be solved by the present invention is to provide a recyclable artificial leather having a good texture, high wear resistance, and a luxurious appearance, and a method for producing the same.

Means for Solving the Problem

[0016] As a result of intensive research and repeated experiments to solve the above problems, the inventors of the present invention unexpectedly found that the above problems can be solved by an artificial leather having the following characteristics, and thus completed the present invention. That is, the present invention is as follows.

[0017] [1] An artificial leather including at least a surface fiber layer constituting a first surface, having the following characteristics: (1) The surface fiber layer includes a main fiber and a thermoplastic resin; (2) The fineness of the main fiber is 0.01 dtex or more and 0.5 dtex or less; (3) At least a part of the thermoplastic resin adheres between the main fibers; (4) The number average volume of the thermoplastic resin in the surface fiber layer is 3500 μm 3 or more and 24000 μm 3 or less; and (5) The thermoplastic resin is a copolymer of polyester and aliphatic polyether; The artificial leather having the above. [2] The artificial leather according to [1] above, wherein the main fiber is a polyester fiber. [3] The artificial leather according to [1] or [2] above, wherein the thermoplastic resin is a copolymer of polybutylene phthalate and aliphatic polyether. [4] The artificial leather according to [3] above, wherein the thermoplastic resin is a copolymer of polybutylene phthalate and polytetramethylene ether glycol. [5] The artificial leather according to any one of [1] to [4] above, wherein the surface fiber layer is entangled with a scrim layer which is a woven fabric. [6] The artificial leather according to [5] above, wherein the scrim layer is made of polyester resin fibers. [7] The volume number density of the thermoplastic resin in the surface fiber layer is 0.5×10 12 pieces / m 3 or more and 5.0×10 12 pieces / m 3 or less. The artificial leather according to any one of [1] to [6] above. [8] The average value of the quotient obtained by dividing the major axis by the minor axis when the thermoplastic resin in the surface fiber layer is approximated by an ellipse is 100 or less. The artificial leather according to any one of [1] to [7] above. [9] In accordance with JIS-L-1096 Method E (Martindale method), when the surface is worn under a pressing load of 12 kPa, the scrim is not exposed when the number of wear cycles is less than 50,000. The artificial leather according to any one of [1] to [8] above.

[10] In accordance with JIS-L-1096 Method E (Martindale method), when the surface is worn under a pressing load of 12 kPa, the wear loss at 50,000 wear cycles is 21 mg or less. The artificial leather according to any one of [1] to [9] above.

[11] The following steps: (1) Mixing a main fiber and a heat-fused fiber made of a thermoplastic resin containing a copolymer of polyester and aliphatic polyether so that the weight ratio of the heat-fused fiber is 3% or more and 25% or less, entangling them by wet papermaking, and then forming a surface fiber web by a water jet entanglement treatment or a needle punching method; and (2) Forming a surface fiber layer by thermal annealing of the entangled structure of the obtained surface fiber web at a temperature equal to or higher than the melting point of the heat-fused fiber and lower than the melting point of the main fiber. The manufacturing method of the artificial leather according to any one of [1] to

[10] above, which has the above steps.

[12] The bending modulus of elasticity of the thermoplastic resin is 40 MP or more and 200 MPa or less. The method according to

[11] above.

[13] The fiber length of the heat-fused fiber made of the thermoplastic resin is 2 mm or more and 90 mm or less. The method according to

[11] or

[12] above.

[14] The fiber diameter of the heat-fused fiber made of the thermoplastic resin is 0.5 dtex or more and 2.2 dtex or less. The method according to any one of

[11] to

[13] above.

[15] The heat-fusible fibers produced using the thermoplastic resin are produced by melt spinning, according to the method described in any one of

[11] to

[14] .

[16] The method for producing artificial leather according to any one of

[11] to

[15] , wherein 95% by weight or more of the thermoplastic resin is a copolymer of polyester and aliphatic polyether.

Advantages of the Invention

[0018] In the artificial leather according to the present invention, the thermoplastic resin adheres the main fibers having a fineness of 0.01 dtex or more and 0.5 dtex or less, and by setting the number average volume of the thermoplastic resin in the surface fiber layer within a predetermined range, it is excellent in abrasion resistance and texture. Further, if the artificial leather according to the present invention uses polyester-based fibers as the main fibers and the thermoplastic resin and does not contain an elastic polymer such as aqueous polyurethane, it is excellent in recyclability and is also excellent in flame resistance in that it can suppress the generated gas during combustion. In particular, by specifying the thermoplastic resin as a copolymer of polyester and aliphatic polyether, high abrasion resistance and a supple texture are achieved.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described in detail. The first embodiment of the present invention is artificial leather including at least a surface fiber layer constituting a first surface, and has the following features: (1) The surface fiber layer includes a main fiber and a thermoplastic resin; (2) The fineness of the main fiber is 0.01 dtex or more and 0.5 dtex or less; (3) At least a part of the thermoplastic resin adheres between the main fibers; (4) The number average volume of the thermoplastic resin in the surface fiber layer is 3500 μm 3 or more and 24000 μm 3 or less; and (5) The thermoplastic resin is a copolymer of polyester and aliphatic polyether; The artificial leather having the above.

[0021] The main fiber contained in the surface fiber layer is a fiber contained in an amount of 60% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more with respect to 100% by mass of the surface fiber layer. The upper limit is not particularly limited, but may be 99% by mass or less. The main fiber contained in the surface fiber layer is preferably a polyester-based fiber, a polyamide-based fiber, an acrylic-based fiber, or a polyolefin-based fiber from the viewpoints of strength, ease of manufacturing ultrafine fibers, and general market availability. However, as described above, considering applications that require durability such as the car seat field, polyethylene terephthalate is preferable in that the fiber itself does not turn yellow or the like even when exposed to direct sunlight for a long time and has excellent dyeing fastness. Further, from the viewpoint of reducing the environmental load, polyethylene terephthalate that has been chemically recycled or material recycled, or polyethylene terephthalate using plant-derived raw materials is more preferable.

[0022] As the polyester-based fibers serving as the main fibers constituting the surface fiber layer, polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactate, their copolymers, etc. are preferably used. As the polyamide-based fibers, nylon, meta-aramid, para-aramid, their copolymers, etc. are preferably used. As the acrylic-based fibers, polymers of acrylic acid esters or methacrylic acid esters, their copolymers, etc. are preferably used. As the polyolefin-based fibers, polyethylene, polypropylene, polybutene, polystyrene, their copolymers, etc. are preferably used. These fibers can be used alone, or fibers of various polymers may be mixed at any ratio.

[0023] If not only the main fibers but also the thermoplastic resin contained in the surface fiber layer described below and the scrim are made of a polyester-based resin, for example, PET after use can be recovered from clothing or beverage bottles, processed into recycled PET resin, used to manufacture artificial leather, and then the used (worn-out) artificial leather can be recycled and processed into, for example, heat insulation materials or filter materials, and further PET can be recovered from the used heat insulation materials and filter materials, making it possible to obtain a recyclable artificial leather with circular economy suitability.

[0024] From the viewpoint of a texture similar to natural leather and the ease of obtaining a suede or nubuck-like surface feel, the fineness of the main fibers is preferably 0.5 dtex or less, more preferably 0.35 dtex or less, and even more preferably 0.2 dtex or less. Also, from the viewpoints of production efficiency, production stability, and manifestation of abrasion resistance during fiber production, the fineness is preferably 0.01 dtex or more, and more preferably 0.03 dtex or more. As the main fibers, fibers directly spun by the melt spinning method, fibers obtained by the wet spinning method, ultrafine fibers obtained by removing the sea component from sea-island fibers using copolymerized polyester as the sea component and regular polyester as the island component, etc. can be used.

[0025] As long as the desired effects are achieved, additives may be mixed in or adhered to the main fiber. Additives refer to titanium oxide, various antioxidants, light-resistant agents, antistatic agents, flame retardants, softeners, fastness improvers, pigments such as carbon black, dyes, and the like.

[0026] When selecting a method using short fibers as the method for manufacturing the main fiber, the short fiber length in the case of the dry method (carding method, airlaid method, etc.) is preferably 13 mm or more and 102 mm or less, more preferably 25 mm or more and 76 mm or less, and still more preferably 38 mm or more and 76 mm or less. In the case of the wet method (papermaking method, etc.), it is preferably 1 mm or more and 30 mm or less, more preferably 2 mm or more and 25 mm or less, and still more preferably 3 mm or more and 20 mm or less. For example, the aspect ratio (L / D), which is the ratio of the length (L) to the diameter (D) of the short fibers used in the wet method (papermaking method, etc.), is preferably 500 or more and 2000 or less, more preferably 700 to 1500. Such an aspect ratio is preferable because the dispersibility and fibrillation property of the short fibers in the slurry when preparing the slurry by dispersing the short fibers in water are good, the fiber layer strength is good, the fiber length is shorter and the single fibers are easier to disperse compared with the dry method, and it is difficult to form a fuzz-like appearance called pilling due to friction. For example, the fiber length of short fibers with a diameter of 4 μm is preferably 2 mm or more and 8 mm or less, more preferably 3 mm or more and 6 mm or less.

[0027] The thermoplastic resin has the function of maintaining a three-dimensionally intertwined state by fusing and bonding the main fibers together, and at least a part of it is required to adhere between the main fibers. When the thermoplastic resin does not adhere between the main fibers, the retention between the main fibers is insufficient, and fiber shedding and breakage are likely to occur, so it does not have satisfactory abrasion resistance and strength as artificial leather. The adhesion referred to here refers to the states shown in Figures 2, 3, and 4. Regarding its composition, in addition to achieving high abrasion resistance and a supple texture, from the perspective of excellent chemical resistance to acids, alkalis, and artificial sebum during actual use of artificial leather, it is necessary to be a copolymer of polyester and aliphatic polyether. Among them, as the polyester, polybutylene phthalate-based resin is preferable, a copolymer of polybutylene phthalate and aliphatic polyether is preferred, it is more preferable to use a copolymer of polybutylene phthalate and polytetramethylene ether glycol, and a block copolymer of polybutylene phthalate and polytetramethylene ether glycol is particularly preferred. Here, the form of the copolymer is not particularly limited, but it is particularly preferable to have a moderate coexistence of soft segments and hard segments and to be a block copolymer from the simplicity of the manufacturing method. The existence ratio of the soft segment can be calculated by the following formula. Existence ratio of soft segment (%) = Number of monomer units of soft segment × 100 / (Total number of monomer units of soft segment and hard segment) The existence ratio (%) of the soft segment can be calculated using 1H-NMR, and it is preferably 40% or more and 85% or less in terms of the soft segment ratio, and particularly preferably 50% or more and 75% or less. In the copolymer of polybutylene phthalate and polytetramethylene ether glycol, polybutylene phthalate is the hard segment and polytetramethylene ether glycol is the soft segment.

[0028] Here, "phthalate-based" refers to the general term for a group of benzenedicarboxylic acid compounds. That is, isomers such as 1,2-benzenedicarboxylic acid, 1,3-benzenedicarboxylic acid, and 1,4-benzenedicarboxylic acid can be used in any proportion. There is no particular regulation regarding the form of use in any proportion, and a single isomer can be used, or homopolymers in any proportion can be mixed, or these isomers can be copolymerized.

[0029] Castven 8000 used in Comparative Examples 1 and 2 below, Meltie 4080 used in Comparative Example 3, and Castven 8080 used in Comparative Example 6 do not contain aliphatic polyethers and are not copolymers of polyester and aliphatic polyether. Also, Pebax 6333SP01 used in Comparative Example 4 is a nylon-based elastomer.

[0030] The thermoplastic resin does not necessarily have to be composed of only a single polymer, and a plurality of polymers may be mixed. Also, as long as the desired effects are achieved, additives may be mixed or adhered to this thermoplastic resin. Additives refer to titanium oxide, various antioxidants, light-resistant agents, antistatic agents, flame retardants, softeners, fastness improvers, pigments such as carbon black, dyes, and the like.

[0031] The flexural modulus of the thermoplastic resin is preferably 40 MPa or more and 200 MPa or less. By setting the flexural modulus within the above range, the size and distribution of the fusion points of the heat-fused resin during heat annealing can be controlled, and both good wear resistance and texture can be achieved. Based on this mechanism of action, by setting the flexural modulus in the range of 40 MPa or more and 200 MPa, while sufficiently adhering the main fibers to each other, when touched with a finger, appropriate fuzziness can give a sense of fluttering and express the high-class touch required for artificial leather. Regarding the range of the flexural modulus, from the viewpoint of maintaining particularly good appearance quality, it is preferably 41 MPa or more and 150 MPa or less, and more preferably 45 MPa or more and 120 MPa or less.

[0032] The thermoplastic resin must be present in the form of a lump on both the surface and cross section of the surface fiber layer, and the number-average volume must be less than 3500 μm 3 More than 24000μm 3 If it is present only on the surface and not in a block shape in the cross section, the main fibers are not sufficiently held together by the resin fusion, and not only does it not have sufficient abrasion resistance as artificial leather, but the density of the surface fiber layer does not increase sufficiently, and it is not possible to express the luxurious, moist texture that is characteristic of artificial leather. 3 If it exceeds 3500 μm, the resin masses present on the surface will be too large relative to the main fibers, impairing the appearance quality and the feel, and the density of the fusion points between the main fibers will be small, and the main fibers will not be held together sufficiently, resulting in poor abrasion resistance of the surface layer. 3 If the number average volume is less than 4000 μm, the particle size is insufficient to bond the main fibers together, and abrasion resistance cannot be achieved. 3 More than 22000μm 3 Less than or equal to 6000 μm, more preferably 3 More than 20000μm 3 The following is the result.

[0033] The volume density of the thermoplastic resin in the surface fiber layer is 0.5×10 12 pieces / m 3 Above 5.0×10 12 pieces / m 3 The number of particles per unit volume of the thermoplastic resin is preferably 0.5×10 or less. 12 pieces / m 3 When the thermoplastic resin is more than 5.0×10 per unit volume, multiple main fibers can be bonded with multiple heat fusion resins, and the fiber bundles are less likely to fall off when worn, and wear resistance can be exhibited. 12 pieces / m 3 If the volume density is less than 0.6×10, the surface fiber layer does not become too hard, and the supple, luxurious feel required for artificial leather can be obtained. 12pcs / m 3 3.0×10 12 pcs / m 3 or less, more preferably 0.8×10 12 pcs / m 3 or more and 1.5×10 12 pcs / m 3 or less.

[0034] It is preferable that the thermoplastic resin adheres to the main fibers isotropically when viewed from any three-dimensional angle. Specifically, it is preferable that the average value of the quotient obtained by dividing the major axis by the minor axis when the thermoplastic resin in the surface fiber layer is approximated by an ellipse is 100 or less. If the average value of the quotient obtained by dividing the major axis by the minor axis when the thermoplastic resin is approximated by an ellipse is 100 or less, the hot-melt resin is sufficiently melted when adhering the main fibers, the adhesive strength becomes high, and high abrasion resistance can be obtained. The average value of the quotient obtained by dividing the major axis by the minor axis when the thermoplastic resin is approximated by an ellipse is more preferably 10 or less, and even more preferably 5 or less. Since it is preferable that the thermoplastic resin approaches a perfect sphere (quotient value 1), although not particularly limited, the average value of the quotient obtained by dividing the major axis by the minor axis when the thermoplastic resin is approximated by an ellipse may be 1 or more.

[0035] Regarding the evaluation method of the above thermoplastic resin, it can be evaluated by methods such as vertically cutting the artificial leather and observing it with an optical microscope or an electron microscope, or measuring a three-dimensional image by measurement such as CT or MRI. It is required to accurately evaluate not only the surface layer of the surface fiber layer but also the position, existence density, shape, and size of the hot-melt resin inside. However, by performing continuous image analysis of the cross-section in the X-ray CT described in the examples and performing mathematical analysis following the procedure of appropriately processing the images, accurate evaluation can be achieved.

[0036] Another embodiment of the present invention is the following steps: (1) Mixing a main fiber and a hot-melt fiber produced using a thermoplastic resin containing a copolymer of polyester and aliphatic polyether so that the weight ratio of the hot-melt fiber is 3% or more and 25% or less, entangling them by wet papermaking, and then forming a surface fiber web by a water stream entanglement treatment or a needle punching method; and (2) Forming a surface fiber layer by thermal annealing the entangled structure of the obtained surface fiber web at a temperature equal to or higher than the melting point of the heat-fusible fiber and lower than the melting point of the main body fiber; This is the method for manufacturing the artificial leather having the above.

[0037] The artificial leather of this embodiment can use a scrim layer as a core material. When using a scrim layer, from the viewpoints of stabilizing the production of the paper-making sheet in the papermaking process and increasing the mechanical strength of the obtained artificial leather, the scrim layer to be used is preferably a woven fabric or a knitted fabric. From the viewpoint of color uniformity in dyeing, the material of the scrim layer is preferably the same polymer system as the main body fiber. In the case of a knitted fabric, a single knit knitted at 22 gauge or more and 28 gauge or less is preferable. In the case of a woven fabric, it is more preferable because higher dimensional stability and strength than those of a knitted fabric can be achieved. The yarns constituting the woven fabric may be monofilaments or multifilaments. The single fiber fineness of the yarn is preferably 5.5 dtex or less in terms of easily obtaining a flexible artificial leather using an entangled sheet. As the form of the yarns constituting the woven fabric, raw yarns of multifilaments such as polyester and polyamide, or processed yarns subjected to false-twist processing and the like twisted at a twist number of 0 to 3000 T / m are preferable. The multifilament may be a normal one. For example, 33 dtex / 6f, 55 dtex / 24f, 83 dtex / 36f, 83 dtex / 72f, 110 dtex / 36f, 110 dtex / 48f, 167 dtex / 36f, 166 dtex / 48f, etc. of polyester, polyamide, etc. are preferably used. The yarns constituting the woven fabric may be multifilament long fibers. The weaving density of the yarns in the woven fabric is preferably 30 threads / inch or more and 150 threads / inch or less, more preferably 40 threads / inch or more and 100 threads / inch or less, in terms of obtaining a flexible and mechanically strong artificial leather. In order to have good mechanical strength and an appropriate texture, the basis weight of the woven fabric is 20 g / m 2 or more and 150 g / m 2The following are preferred. Incidentally, the presence or absence of false twisting treatment, the number of twists, the single fiber fineness of multifilament, the fabric density, etc. in the fabric contribute not only to the entanglement with the constituent fibers of the main fiber layer and the flexibility of the artificial leather, but also to the mechanical properties such as seam strength, tear strength, tensile strength and elongation, stretchability, etc. Therefore, they may be appropriately selected according to the target physical properties and uses.

[0038] The artificial leather of this embodiment can include at least a surface fiber layer constituting the first surface. For example, in the case of artificial leather composed of a surface fiber layer and a scrim layer, the first surface (the upper surface) becomes the surface (the front surface), and the back surface of the scrim layer becomes the second surface (the lower surface). Further, when the artificial leather of this embodiment is composed of three layers of a surface fiber layer / a scrim layer / a back surface fiber layer, the back surface of the back surface fiber layer becomes the second surface. Moreover, when adopting the structure of a surface fiber layer / a scrim layer / a back surface fiber layer as one aspect of this embodiment, the material constituting the back surface fiber layer is not particularly limited, but from the viewpoint of exhibiting good recyclability, it is preferably the same as the main fiber of the surface fiber layer and / or a thermoplastic resin. Further, when including a back surface fiber layer, it is different from the surface fiber layer, and for example, a flame retardant can be imparted to add desired characteristics.

[0039] As a manufacturing method of the artificial leather of this embodiment, a method of heat-treating a nonwoven fabric structure in which a main fiber and a fully meltable heat-fusible fiber are mixed to form a surface fiber layer is preferable, so that the heat-fusible fiber is melted and a massive thermoplastic resin is formed in the surface fiber layer. This heat-fusible fiber is preferably a fully meltable fiber so that the number of points where the massive resin after melting fuses between the main fibers is sufficient. Compared with the case of using a sheath-core type fiber using a low melting point thermoplastic resin in the sheath part or a side-by-side type fiber using a low melting point thermoplastic resin only on one side, a fully meltable fiber has more points of adhering between the main fibers and a larger amount of fusion component in the fusion part, so it is preferable in terms of sufficient fusion force. Also, since the fusion points do not continuously exist in the vicinity via the heat-fusible fiber, it is also preferable in terms of being likely to have a soft texture.

[0040] As described above, the form of the heat-sealable fiber is not particularly limited as long as it is a copolymer of polyester and aliphatic polyether. It can be selected from all-melt type fibers composed of a single component of these polymers, composite type fibers such as core-sheath type and side-by-side type composed of two or more components of these polymers, etc. However, from the viewpoints of high heat-sealing strength and color uniformity in dyeing, it is preferable to use the same polymer system as the main fiber. Also, in terms of obtaining high heat-sealing strength and a soft texture, it is preferable to select all-melt type heat-sealable fibers. When a composite type is selected, for example, when the core-sheath type is selected, there are drawbacks such as the texture becoming hard, and it being difficult to obtain high abrasion resistance because the amount of the heat-sealing component in the heat-sealed part is small, or the heat-sealed part being easily peeled off in the dyeing process or the like, making it difficult to achieve a high-class appearance. The resin component contained in the above heat-sealable fiber is preferably 95% or more, but additives may be mixed or adhered as long as the desired effects are achieved. Additives refer to titanium oxide, various antioxidants, light-resistant agents, antistatic agents, flame retardants, softeners, fastness improvers, pigments such as carbon black, dyes, etc. The preferable range of the resin component contained in the above heat-sealable fiber is more preferably 96% or more, still more preferably 97% or more.

[0041] The melting point of the heat-sealable fiber can be measured by DSC (differential scanning calorimeter) as described in the examples, and is preferably 140°C or higher and 200°C or lower, more preferably 155°C or higher and 185°C or lower. Also, the melting point of the heat-sealable fiber is preferably 20°C or lower than the melting point of the main fiber.

[0042] The heat-sealing fiber does not necessarily have to be composed of only a single polymer, and a plurality of types of polymers may be mixed. From the viewpoints of high heat-sealing force and identity in dyeing, it is preferable that the polymer system is the same as that of the main fiber. The heat-sealing fiber can be a fiber directly spun by a melt spinning method, a fiber obtained by a wet spinning method, an ultrafine fiber obtained by removing the sea component from a sea-island fiber using a copolymerized polyester as the sea component and a regular polyester as the island component, and the like. From the viewpoint of the size of the molten bulk thermoplastic resin, the fiber diameter of this heat-sealing fiber is preferably 0.5 dtex or more and 2.2 dtex or less. If the fineness is 2.2 dtex or less, the molten bulk thermoplastic resin is uniformly dispersed on the surface of the surface fiber layer, and the appearance quality and texture are excellent. The fineness of the heat-sealing fiber is more preferably 0.6 dtex or more and 2.0 dtex or less, and even more preferably 0.7 dtex or more and 1.5 dtex or less.

[0043] As a method for forming the surface fiber layer, there are methods such as using the main fiber and / or the heat-sealing fiber in the form of short fibers and entangling the fibers using a papermaking method, a carding method, an air-laying method, etc. to form a non-woven fabric structure. From the viewpoints of uniform dispersibility of the constituent fibers and ease of use of ultrafine fibers, it is particularly preferable that the surface fiber layer is formed by a papermaking method.

[0044] In addition, for the entanglement between the layers in this embodiment, a water-jet entanglement method called a spunlace method, a needle punching method, etc. can be used, but a water-jet entanglement method that does not destroy the structure of the woven or knitted fabric of the scrim layer is preferable.

[0045] For heat fusion treatment (heat annealing), a drum dryer, a contact dryer such as a calendar roll, an air-through dryer such as a biaxially stretched film stretching machine or a pin tenter dryer can be used. The treatment (heat annealing) temperature is 5°C or more higher than the melting point of the thermoplastic resin, preferably 10°C or more higher and 240°C or less. If the difference between the treatment temperature and the melting point of the thermoplastic fiber is less than 5°C, a sufficient heat fusion effect may not be obtained. If the treatment temperature exceeds 240°C, the polyester fiber may melt and the surface quality and abrasion resistance may not be fully exhibited.

[0046] During heat annealing, it is preferable to relax the nonwoven fabric structure. By performing the above heat fusion while sagging and shrinking the surface fiber web entangled with the scrim layer in the MD direction, which is the manufacturing process progress direction of the nonwoven fabric structure, and the CD direction perpendicular to the MD direction, the entangled structure is in a relaxed state, that is, the main fibers are fixed in a state of not being tense. Therefore, compared with the conventional method of performing heat fusion while tensioning and shrinking using a pin tenter, artificial leather with high abrasion resistance and good texture can be obtained.

[0047] From the viewpoints of uniform dispersibility and fibrillation property with the main fibers in the slurry when preparing a slurry by dispersing short fibers in water, the fiber length of the heat-fused fibers is preferably 2 mm or more and 90 mm or less. By setting the fiber length of the heat-fused fibers within the above range, dispersibility and fluidity in water similar to those of the main fibers can be obtained. Therefore, the heat-fused fibers can be three-dimensionally isotropically present when forming a sheet web, and it is easy to realize the desired dispersion state of the heat-fused resin when heat-annealed.

[0048] The weight mixing ratio of the heat-fusing fiber is preferably 3% or more and 25% or less. The weight mixing ratio is a value expressed as a percentage of the weight of the heat-fusing fiber with respect to the total weight of the main fiber and the heat-fusing fiber. If the mixing ratio is less than 3%, sufficient fusing force cannot be obtained, making it difficult to obtain good abrasion resistance and shape stability. On the other hand, if the mixing ratio exceeds 25%, the texture becomes too firm, which is not preferable. This weight mixing ratio is more preferably 4% or more and 20% or less, and even more preferably 6% or more and 15% or less.

[0049] The artificial leather obtained by the above method is used as suede-like or nubuck-like artificial leather by raising the surface of the surface fiber layer and performing a dyeing treatment. As the raising treatment, known methods such as buffing with sandpaper can be used. In that case, if the raising treatment is performed before heat-fusing the heat-fusing fibers in the surface fiber layer, a suede-like surface feel can be obtained. On the other hand, if the raising treatment is performed after heat-fusing the heat-fusing fibers, a nubuck-like surface feel can be obtained.

[0050] The dyeing treatment is not particularly limited. For example, when the main fiber is a polyester-based fiber, it is common to use disperse dyes. The dyeing method can be a conventional method well-known to dyeing processors, and in the case of artificial leather, a liquid flow dyeing machine is preferably used from the viewpoint of level dyeing property. The artificial leather dyed in this way is reductively washed in the presence of soaping or a chemical reducing agent to remove excess dye. The conditions for the reductive washing are not particularly limited, and a basic reducing agent or an acidic reducing agent can be used according to a conventional method without particular limitation.

[0051] The thickness of the artificial leather of this embodiment is preferably 0.40 mm to 1.50 mm. By having the thickness of the artificial leather within the range of 0.40 mm or more and 1.50 mm, while sufficiently ensuring the thickness of the surface fiber layer, it is possible to sufficiently maintain the fusion points per unit area and the entanglement between the fibers in the surface fiber layer on the surface, so that a supple touch and sufficient stretchability can be achieved simultaneously.

[0052] The basis weight of the artificial leather of this embodiment is 100 g / m 2 ~400 g / m2 It is preferably such that. The basis weight is 100 g / m 2 ~400 g / m 2 By setting it like this, it is possible to achieve both a supple touch and an appropriate hardness.

[0053] When the artificial leather of this embodiment is used as artificial leather, in order to have good abrasion resistance, it conforms to JIS-L-1096 Method E (Martindale method), and when the surface is abraded at a pressing load of 12 kPa, it is preferable that the scrim does not become exposed when the number of abrasion cycles is less than 50,000 times.

[0054] Similarly, when the artificial leather of this embodiment conforms to JIS-L-1096 Method E (Martindale method) and the surface is abraded at a pressing load of 12 kPa, it is preferable that the abrasion loss is 21 mg or less at 50,000 abrasion cycles.

Examples

[0055] Hereinafter, the present invention will be specifically described based on examples and comparative examples, but the present invention is not limited only to these examples. The physical property values used in the examples and the like were measured by the following methods.

[0056] (1) Melting point The melting point of the heat-sealable fiber was determined as follows: 3 mg of the heat-sealable fiber was placed in a nitrogen atmosphere, and using aluminum as a reference substance with a DSCQ100 manufactured by TA Instruments, the temperature was raised from 25°C to 250°C at a rate of 10°C / min and then rapidly cooled, and the peak top of the endothermic peak that appeared when the temperature was raised under the same conditions for the second time was taken as the melting point.

[0057] (2) Flexural modulus (MPa) of the thermoplastic resin Thermoplastic resin pellets were inserted between the presses with a spacer, and melt-compressed under the conditions of a temperature 20 °C higher than the melting point, 10 MPa, and 5 min, and molded into a square sheet with a side length of 150 mm and a thickness of 4 mm. A test piece of 80 mm × 10 mm was cut out from this sheet, and evaluated by the stress gradient in the specified deflection range (0.05 - 0.25%) according to the 3-point bending test secant method JIS K7171 (speed 2 mm / Min, span 64 mm) using a universal material testing machine (model 5967, manufactured by Instron). Evaluation was performed on 6 test specimens for each sample, and the average value was calculated.

[0058] (3) Reduced viscosity (ηsp / c) The reduced viscosity (ηsp / c) is measured as follows. 0.35 g of the resin that is the raw material of the heat-sealing fiber is added to 0.25 deciliter of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), and dispersed at room temperature for 3 hours using a magnetic stirrer to prepare a diluted solution. The obtained diluted solution is added to an Ubbelohde viscometer tube (tube diameter: 0.03), and the falling seconds of the diluted solution and the HFIP solvent are measured in a water bath adjusted to 25 °C ± 0.1 °C to obtain the specific viscosity (ηsp). After the measurement, the diluted solution is weighed and dried in an oven at 120 °C for 1 hour, and the polymer concentration C (g / dl) is calculated from the obtained solid content. The specific viscosity (ηsp) is divided by the polymer concentration C (g / dl) to obtain the reduced viscosity ηsp / c. Note that the solvent and the amount of solvent may be changed according to the type of the resin that is the raw material of the heat-sealing fiber.

[0059] (4) Number-average volume (μm 3 ), volume number density (10 12 pieces / m 3 ) [Image measurement using X-ray CT] Observation of the molten point mass was performed using an X-ray CT device ("High-resolution 3D X-ray microscope Nano3DX" manufactured by Rigaku Corporation), observing the entire thickness direction of the artificial leather. A 3D image was taken with the central part in the cross-section in the thickness direction as the center point of the observation area. Image measurement was performed under the conditions of using copper for the X-ray target, an X-ray tube voltage of 40 kV, a tube current of 30 mA, an exposure time of 12 seconds per sheet, and a spatial resolution of 1.08 μm / pixel. Through the same operation, 1000 images were taken every 180 degrees of rotation angle to obtain 3D measurement data.

[0060] [Image processing method, analysis method, and calculation method for the additive average value of the quotient obtained by dividing the major axis by the minor axis when approximated by an ellipse] Details of the processing and analysis process of the 3D measurement data obtained above are described below. Note that the image analysis software used was "ImageJ (version: 1.51j8, National Institutes of Health, USA). (i: Rotation of the image) Rotate the 3D image so that the plane direction of the artificial leather coincides with the plane direction consisting of the xz axes and the thickness direction of the artificial leather coincides with the y axis. (ii: Trimming) Trim the 3D image into a rectangular parallelepiped. At this time, the y axis should include all of the thickness and should not have an excessive amount of space outside the film. Regarding the x and z axes, after determining the range of the y axis, take the maximum range where no pixels outside the measurement field of view enter the trimmed rectangular parallelepiped. (iii: Axis setting) Let the number of pixels in the x-axis direction of the trimmed image be x0, the number of pixels in the y-axis direction be y0, and the number of pixels in the z-axis direction be z0. (iv: Filtering) Perform median filtering under the condition of a radius of 2 pix. (v: Region division) Apply the Otsu method to divide the region. At this time, to clarify the light and dark, set the luminance value of the pixel so that the air part not containing the artificial leather is 0 and the main fiber part constituting the artificial leather is 255. (vi: Segmentation) For pixels with a luminance value of 255, perform segmentation of the image processing method. Structures with 10,000 pixels or fewer in the region of luminance value 255 that are three-dimensionally connected are regarded as noise, and their luminance values are changed to 0 and removed. (vii: Noise removal) Among the pixels with a luminance value of 0, the pixels of 0 that are three-dimensionally surrounded by a luminance value of 255 are regarded as noise, and their luminance values are changed to 255 and removed. (viii: Calculation of porosity) Cut out a 2D image of the xz plane from the 3D image in the thickness direction with a thickness of 1 pix, and calculate the porosity on that plane using the following formula: Porosity = Number of pixels with luminance value 0 / Total number of pixels Obtain it in this way. (ix: Thickness distribution of porosity) Perform the above (viii) for all y data to obtain the distribution of porosity in the y-axis direction. (x: Calculation of the size of high-luminance pixels) Determine the size of the pixels with a luminance value of 255 by the Thickness method. As a result, a 3D image is obtained in which the value of the diameter of the largest sphere that can fit into each pixel becomes the luminance value. The Thickness method is the method described in the literature "A new method for the model-independent assessment of thickness in three-dimensional images" by T. Hildebrand and P. Rueesgsegger, J. of Microscopy, 185 (1996) 67-75, and can be executed, for example, using the Thickness of BoneJ, a plugin of the image analysis software ImageJ. Furthermore, for the image obtained here, structures with a size of 12 μm or less are regarded as the main fibers and removed from the analysis target, so the luminance values of the pixels with a number of pixels corresponding to 12 μm or less are changed to 0. (xi: Binarization) For the image obtained in the above (x), perform binarization by setting all pixels with a luminance value other than 0 to 255 and leaving the pixels with a luminance value of 0 as 0. (xii: Particle analysis) Perform three-dimensional particle analysis on the image obtained in (xi) above. Consider a three-dimensionally continuous portion with a luminance value of 255 as one particle, and calculate the center coordinates (XC, YC, ZC) of each particle as well as the number of pixels in the continuous structure. (xiii: Definition of surface, scrim layer, and back surface) In the data of the porosity distribution obtained in (ix) above, use the range of 95% for analysis (excluding the outermost surfaces of the front and back surfaces). Therefore, on the surface of the artificial leather, define the value of the y-axis farthest from the front side where the porosity is 0.95 or more as y1. When the scrim layer is included, define the portion where the porosity value in (viii) and fibers with a fineness of 100 dtex or more appear as the front end, and set its coordinate as y2. (xiv: Calculation of total number of pixels and data analysis) For the particles among all the particles obtained in (xii) above whose coordinate values satisfy y1 < YC < y2, find the number of particles and the total sum of the number of pixels of the particles. Number-average volume (μm 3 ) = Total sum of particle pixel numbers * p * p * p ÷ Number of particles Volume number density (10 12 particles / m 3 ) = Number of particles ÷ (|y2 - y1| * p * x0 * p * z0 * p) Here, p is the pixel size (m / pix), which is the actual size (m) of 1 pixel (pix). (xv: Calculation of average value of quotient of major axis divided by minor axis when approximated by an ellipse and data analysis) Perform three-dimensional particle analysis on the image obtained in (xi) above. Consider a three-dimensionally continuous portion with a luminance value of 255 as one particle, and approximate each particle as an ellipsoid. From the three axes of the ellipsoid, the larger ones are the major axis, the middle axis, and the minor axis. Calculate the average value of the quotient of the major axis divided by the minor axis when each particle is approximated by an ellipse using the following formula: Quotient of major axis divided by minor axis (major axis / minor axis ratio of thermoplastic resin) = Major axis length / Minor axis length The measured value is the additive average of 30 measurement points. However, if the major axis of the approximated ellipsoid is larger than the minimum axis of the rectangular parallelepiped to be analyzed, it is excluded as an error and the aspect ratio is set to 0. Calculate the average aspect ratio using the following formula: Quotient of the average major axis divided by the minor axis = Sum of the quotients of the major axes of the particles divided by their minor axes ÷ (Total number of particles - Total number of excluded particles) It was calculated by

[0061] (5) Explanation of the heat fusion point structure Using the figures, the state of the massive resin and its determination will be explained. Figure 1 shows an example where it is exposed on the surface of the surface fiber layer but the main fibers are not adhered to each other. Figure 2 shows an example where it is exposed on the surface and the main fibers are adhered to each other. Figure 3 shows an example where it is not exposed on the surface but the main fibers are adhered to each other. Figure 4 shows an example where it is exposed on the surface and the main fibers are adhered to each other. Figure 5 shows an example where it is exposed on the surface but the main fibers are not adhered to each other. Figure 6 shows an example where the heat-fused fibers are not melted and is not referred to as a massive resin. Figure 7 shows an example where sheath-core fibers are used as the heat-fused fibers and the heat-fused fibers remain in fiber form and are not referred to as a massive resin. Figure 8 shows an example where it is exposed on the surface but the main fibers are not adhered to each other. In the figures, 1 is the main fiber, 2 is the massive resin, 3 is the unmelted resin, and 4 is the sheath-core fiber. Here, "the main fibers are adhered to each other" means a state where at least two or more main fibers penetrate through the inside of the massive resin (thermoplastic resin) and are physically bonded.

[0062] (6) Denier Any 10 locations on the surface or back fiber layer sample of the artificial leather were photographed at a magnification of 2500 times with a microscope, the diameters of 50 fibers were measured, and their average value was obtained as the average fiber diameter. From the obtained average fiber diameter and the density of the main fibers, the denier [dtex] of the main fibers was determined. Also, the artificial leather was immersed in ethanol, wrapped in a gelatin capsule, freeze-dried in liquid nitrogen, cut with a knife for each capsule, and the cut cross-section of the sample returned to room temperature was observed using a scanning electron microscope (JSM-5610 manufactured by JEOL Ltd.) under the conditions of WD = 10 mm and a magnification of 200 times. The fineness of the yarns constituting the scrim layer was determined by measuring the thickness of the yarns constituting the scrim layer, measuring 5 points each from 20 obtained images. The fineness of the heat-fused fiber is the fineness of the raw material fiber, which was evaluated using a scanning electron microscope. Specifically, an adhesive carbon tape was attached onto the evaluation stage, 0.05 g of the raw material short fibers were placed thereon, and the sample was prepared by removing the excess heat-fused fibers with an air duster. The sample was observed under the conditions of WD = 10 mm and a magnification of 200 times, and the fineness was determined by measuring the thickness of five points each from 20 obtained images.

[0063] (7) Abrasion resistance and wear loss The abrasion of the sample surface was carried out at a pressing load of 12 kPa by the method specified in JIS-L-1096 Method E (Martindale method). As the evaluation criteria for this test method, the abrasion was evaluated according to the following evaluation criteria (grades) based on the number of abrasion cycles until the surface layer of the sample was worn and a part where the scrim was exposed occurred. (Evaluation criteria) ××: Fiber shedding was significant at 5000 abrasion cycles, and evaluation was not possible. ×: The scrim was exposed at less than 30000 abrasion cycles. △: The scrim was exposed at 30000 or more and less than 40000 abrasion cycles. ○: The scrim was exposed at 40000 or more and less than 50000 abrasion cycles. ◎: The scrim was exposed at 50000 or more abrasion cycles. In addition, the weight change [mg] before and after abrasion of 50000 cycles of a sample of artificial leather (circular shape with a diameter of 40 mm) specified in JIS-L-1096 Method E (Martindale method) at a pressing load of 12 kPa was evaluated as the wear loss. The measurement was performed three times, and the arithmetic mean was taken as the result.

[0064] (8) Tactile evaluation The obtained dyed artificial leather samples were cut out to a size of 25 cm square, arranged on a table with the surface facing up, and 20 subjects (10 males and 10 females, two each from their 20s to 60s) were asked to conduct a test to confirm the tactile sensation along the raised surface with their eyes covered. At the same time, a similar tactile test was also requested for natural suede, and a sensory evaluation was performed on the suppleness and elegance of the surface on a 5-point scale (with suede being 5 points), and the scores were rounded off to two decimal places. 〇: Average score of sensory evaluation is 4.0 or higher △: Average score of sensory evaluation is 3.0 or higher and less than 4.0 ×: Average score of sensory evaluation is less than 3.0

[0065] The manufacturing method of the resin used as the raw material of the heat-sealing fiber will be described below. [Resin Manufacturing Example 1] A polycondensation reaction was carried out using dimethyl terephthalate, 1,4-butanediol, and polytetramethylene glycol to obtain a polyester-polyether block copolymer elastomer. The specific experimental conditions are shown below. 1000 g of dimethyl terephthalate, 650 g of 1,4-butanediol, and 8.3 g of tetrabutoxytitanium(IV) were added to a 5 L autoclave-type reactor with an agitation device manufactured by Shibata Chemical Co., Ltd. After sufficient nitrogen substitution, the pressure was increased to 2 atm with nitrogen, and then the polycondensation reaction was carried out by reacting at 250 °C for 5 hours under the agitation condition of 50 rpm to obtain a prepolymer. Next, 1210 g of polytetramethylene glycol with a number average molecular weight of 2000 was added, and the polycondensation reaction was continued at 250 °C while reducing the pressure to 0.01 atm for 2 hours. After returning to normal temperature and normal pressure, it was taken out from the reaction vessel to obtain polyester-polyether block copolymer elastomer resin 1. The melting point of this polyester-polyether block copolymer elastomer resin 1 was 182 °C, and the reduced viscosity was 3.0 dl / g.

[0066] [Resin Manufacturing Example 2] A polycondensation reaction was carried out using dimethyl terephthalate, dimethyl isophthalate, 1,4-butanediol, and polytetramethylene glycol to obtain a polyester polyether block copolymer elastomer. The specific experimental conditions are shown below. 780 g of dimethyl terephthalate, 220 g of dimethyl isophthalate, 650 g of 1,4-butanediol, and 8.3 g of tetrabutoxytitanium(IV) were added to a 5 L autoclave-type reactor with an agitation device manufactured by Shibata Chemical Co., Ltd. After sufficient nitrogen substitution, the pressure was increased to 2 atm with nitrogen, and then the polycondensation reaction was carried out by reacting at 250 °C for 5 hours under an agitation condition of 50 rpm to obtain a prepolymer. Next, 500 g of polytetramethylene glycol with a number average molecular weight of 2000 was added, and the polycondensation reaction was continuously carried out at 250 °C while reducing the pressure to 0.01 atm for 2 hours. After returning to normal temperature and pressure, it was taken out from the reaction vessel to obtain polyester polyether block copolymer elastomer resin 2. The melting point of this polyester polyether block copolymer elastomer was 170 °C, and the reduced viscosity was 2.3 dl / g.

[0067] [Resin Production Example 3] A polycondensation reaction was carried out using dimethyl terephthalate, dimethyl isophthalate, 1,4-butanediol, and polytetramethylene glycol to obtain a polyester polyether block copolymer elastomer. The specific experimental conditions are shown below. 740 g of dimethyl terephthalate, 260 g of dimethyl isophthalate, 650 g of 1,4-butanediol, and 8.3 g of tetrabutoxytitanium(IV) were added to a 5 L autoclave-type reactor with an agitation device manufactured by Shibata Chemical Co., Ltd. After sufficient nitrogen substitution, the pressure was increased to 2 atm with nitrogen, and then the polycondensation reaction was carried out by reacting at 250 °C for 5 hours under an agitation condition of 50 rpm to obtain a prepolymer. Next, 750 g of polytetramethylene glycol with a number average molecular weight of 2000 was added, and the polycondensation reaction was continuously carried out at 250 °C while reducing the pressure to 0.01 atm for 2 hours. After returning to normal temperature and pressure, it was taken out from the reaction vessel to obtain polyester polyether block copolymer elastomer resin 3. The melting point of this polyester polyether block copolymer elastomer resin 3 was 155 °C, and the reduced viscosity was 3.0 dl / g.

[0068] [Production Example 4 of Resin] A polycondensation reaction was carried out using dimethyl terephthalate, dimethyl isophthalate, 1,4-butanediol, and polytetramethylene glycol to obtain a polyester-polyether block copolymer elastomer. The specific experimental conditions are shown below. 770 g of dimethyl terephthalate, 230 g of dimethyl isophthalate, 650 g of 1,4-butanediol, and 8.3 g of tetrabutoxytitanium(IV) were added to a 5 L autoclave-type reactor with an agitation device manufactured by Shibata Chemical Co., Ltd. After sufficient nitrogen substitution, the pressure was increased to 2 atm with nitrogen, and a polycondensation reaction was carried out by reacting at 250 °C for 5 hours under agitation conditions of 50 rpm to obtain a prepolymer. Next, 1120 g of polytetramethylene glycol with a number average molecular weight of 2900 was added, and the polycondensation reaction was continued to obtain polyester-polyether block copolymer elastomer resin 4. The melting point of this polyester-polyether block copolymer elastomer resin 4 was 163 °C, and the reduced viscosity was 2.9 dl / g.

[0069] Hereinafter, a method for manufacturing a heat-sealable fiber will be described. [Fiber Production Example 1] The resin 1 produced in Resin Production Example 1 was dried in a dehumidifying dryer at a drying temperature of 80 °C for 8 hours, then melt-extruded with a single-screw extruder at an extrusion temperature of 230 °C, and discharged from a spinneret die with 400 holes and a nozzle diameter of 0.15 mm at a spinning temperature of 250 °C and a discharge rate of 0.05 g / min per hole. The filaments were cooled by blowing cooling air at 20 °C and a wind speed of 0.5 m / s at a position about 100 mm to 900 mm below the spinneret die, and a multifilament with a fineness of 200 dtex / 400 filaments was obtained by winding at a winding speed of 1000 m / min. Fifty of the obtained multifilaments were combined into a tow and cut to a fiber length of 5 mm with a rotary cutter at a cutting speed of 80 m / min and a cutting tension of 0.01 g / d to obtain a heat-sealable fiber made of 0.5 dtex of resin 1.

[0070] [Fiber Production Example 2] A multifilament with a fineness of 280 dtex / 400 filaments was obtained in the same manner as in Production Example 1, except that the discharge amount per hole was 0.07 g / min. The obtained multifilament was cut under the same cutting conditions as in Production Example 1 to obtain heat-sealable fibers made of 0.7 dtex of Resin 1.

[0071] [Fiber Production Example 3] A multifilament with a fineness of 440 dtex / 400 filaments was obtained in the same manner as in Production Example 1, except that the discharge amount per hole was 0.11 g / min. The obtained multifilament was cut under the same cutting conditions as in Production Example 1 to obtain heat-sealable fibers made of 1.1 dtex of Resin 1.

[0072] [Fiber Production Example 4] A multifilament with a fineness of 720 dtex / 400 filaments was obtained in the same manner as in Production Example 1, except that the discharge amount per hole was 0.18 g / min. The obtained multifilament was cut under the same cutting conditions as in Production Example 1 to obtain heat-sealable fibers made of 1.8 dtex of Resin 1.

[0073] [Fiber Production Example 5] Using Resin 2 produced in Resin Production Example 2 as a raw material, a multifilament with a fineness of 400 dtex / 400 filaments was obtained in the same manner as in Production Example 1, except that the discharge amount per hole was 0.10 g / min. The obtained multifilament was cut under the same cutting conditions as in Production Example 1 to obtain heat-sealable fibers made of 1.0 dtex of Resin 2.

[0074] [Fiber Production Example 6] Using Resin 3 produced in Resin Production Example 3 as a raw material, a multifilament with a fineness of 400 dtex / 400 filaments was obtained in the same manner as in Production Example 1, except that the discharge amount per hole was 0.10 g / min. The obtained multifilament was cut under the same cutting conditions as in Production Example 1 to obtain heat-sealable fibers made of 1.0 dtex of Resin 3.

[0075] [Fiber Production Example 7] Using the resin 3 produced in Resin Production Example 3 as the raw material, a multifilament with a fineness of 720 dtex / 400 filaments was obtained in the same manner as in Production Example 1, except that the discharge amount per hole was 0.18 g / min. The obtained multifilament was cut under the same cutting conditions as in Production Example 1 to obtain heat-sealable fibers made of resin 3 with a fineness of 1.8 dtex.

[0076] [Fiber Production Example 8] Using the resin 4 produced in Resin Production Example 4 as the raw material, a multifilament with a fineness of 400 dtex / 400 filaments was obtained in the same manner as in Production Example 1, except that the discharge amount per hole was 0.10 g / min. The obtained multifilament was cut under the same cutting conditions as in Production Example 1 to obtain heat-sealable fibers made of resin 4 with a fineness of 1.0 dtex.

[0077] [Fiber Production Example 9] The polyamide copolymer (Arkema Co., Ltd. Pebax 6333SP-01) was dried in a dehumidifying dryer at a drying temperature of 80°C for 8 hours, then melt-extruded with a single-screw extruder at an extrusion temperature of 250°C, discharged from a spinneret die with 400 holes and a nozzle diameter of 0.15 mm at a spinning temperature of 260°C and a discharge amount per hole of 0.10 g / min, and the filaments were cooled by applying cooling air at 20°C and a wind speed of 0.5 m / s at a position about 100 mm to 900 mm below the spinneret die, and wound up at a winding speed of 1000 m / min to obtain a multifilament with a fineness of 400 dtex / 400 filaments. The obtained multifilament was cut under the same cutting conditions as in Production Example 1 to obtain heat-sealable fibers made of Pebax 6333SP-01 with a fineness of 1.0 dtex.

[0078] [Fiber Production Example 10] A multifilament with a fineness of 2000 dtex / 400 filaments was obtained in the same manner as in Production Example 1, except that the discharge amount per hole was 0.50 g / min and the filaments were cooled by applying cooling air with a wind speed of 0.9 m / s. The obtained multifilament was cut under the same cutting conditions as in Production Example 1 to obtain heat-sealable fibers made of resin 1 with a fineness of 5.0 dtex.

[0079] [Example 1] A polyethylene terephthalate fiber with a single fiber fineness of 0.15 dtex and a melting point of 255°C was produced by the direct spinning method, and cut into a length of 5 mm to obtain the main fibers. As the heat-fused fibers, the fibers produced in Production Example 1 (fiber fineness: 0.5 dtex, fiber length: 5 mm) were used. These fibers were dispersed in water at a weight ratio of main fibers: heat-fused fibers = 90:10 to prepare a slurry. A wet-laid sheet for surface fibers with a basis weight of 130 g / m 2 was prepared from this slurry by the wet-laid method. Also, a slurry dispersed in water at a weight ratio of main fibers: heat-melted fibers = 97:3 was used to prepare a wet-laid sheet for back surface fibers with a basis weight of 50 g / m 2 . These two layers were laminated with a woven scrim made of polyethylene terephthalate fibers with a basis weight of 100 g / m, a warp density and weft density sum of 120 (ends / inch), and 166 dtex / 48 f in the MD and CD directions to form a three-layer structure of surface fiber layer / scrim layer / back surface fiber layer. The obtained three-layer laminate was sprayed with a high-speed water flow using a straight-through injection nozzle and entangled, and then dried at 130°C for 5 minutes using an air-through dryer to obtain a nonwoven fabric with a three-layer structure. 2 After raising the surface of the surface fiber layer of the obtained nonwoven fabric by buffing with 400-mesh sandpaper, the nonwoven fabric was slackened in the MD and CD directions to a shrinkage rate of 5% each in a biaxial stretching test apparatus X4HDHT manufactured by Toyo Seiki Seisaku-sho, Ltd., and the center and four corners on both sides were fixed with compression air type grips. Then, the nonwoven fabric was heat annealed in the chamber at 190°C for 5 minutes to obtain a nonwoven fabric for artificial leather. Next, using a blue disperse dye (BlueFBL: manufactured by Sumitomo Chemical Co., Ltd.), it was dyed at 130°C in a jet dyeing machine and subjected to a reduction washing treatment at 80°C to obtain a suede-like artificial leather. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0080] After raising the surface of the surface fiber layer of the obtained nonwoven fabric by buffing with 400-mesh sandpaper, the nonwoven fabric was slackened in the MD and CD directions to a shrinkage rate of 5% each in a biaxial stretching test apparatus X4HDHT manufactured by Toyo Seiki Seisaku-sho, Ltd., and the center and four corners on both sides were fixed with compression air type grips. Then, the nonwoven fabric was heat annealed in the chamber at 190°C for 5 minutes to obtain a nonwoven fabric for artificial leather. Next, using a blue disperse dye (BlueFBL: manufactured by Sumitomo Chemical Co., Ltd.), it was dyed at 130°C in a jet dyeing machine and subjected to a reduction washing treatment at 80°C to obtain a suede-like artificial leather. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0081] [Example 2] Artificial leather 2 with a suede finish was obtained in the same manner as in Example 1, except that the fiber produced in Fiber Production Example 2 (Resin 1, fineness 0.7 dtex, fiber length 5 mm) was used as the heat-sealing fiber. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0082] [Example 3] Using the fiber produced in Fiber Production Example 3 (Resin 1, fineness 1.1 dtex, fiber length 5 mm) as the heat-sealing fiber, and setting the basis weight of the sheet for forming the surface fibers to 140 g / m 2 Artificial leather 3 with a suede finish was obtained in the same manner as in Example 1. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0083] [Example 4] Using the fiber produced in Fiber Production Example 3 (Resin 1, fineness 1.1 dtex, fiber length 5 mm) as the heat-sealing fiber, setting the basis weight of the sheet for forming the surface fibers to 150 g / m 2 and setting the ratio of the surface fiber layer to the main fiber: heat-sealing fiber = 88:12 by weight ratio, and the ratio of the back fiber layer to the main fiber: heat-sealing fiber = 95:5 by weight ratio, artificial leather 4 with a suede finish was obtained in the same manner as in Example 1. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0084] [Example 5] The length of the fiber produced in Fiber Production Example 3 (Resin 1, fineness 1.1 dtex) used as the heat-sealing fiber was changed to 3 mm, the weight ratio of the sheet for forming the surface fibers was changed to the main fiber: heat-sealing fiber = 94:6, and the basis weight of the sheet for forming the surface fibers was set to 110 g / m 2 Artificial leather 5 with a suede finish was obtained in the same manner as in Example 1. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0085] [Example 6] The fiber length of the fiber produced in Fiber Production Example 3 (Resin 1, fineness 1.1 dtex) as the heat-fusing fiber was changed to 8 mm, and the weight ratio of the sheet for making the surface fiber was changed to main fiber:heat-fusing fiber = 94:6. Otherwise, in the same manner as in Example 1, suede-like artificial leather 6 was obtained. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0086] [Example 7] Using the fiber produced in Fiber Production Example 4 (Resin 1, fineness 1.8 dtex, fiber length 5 mm) as the heat-fusing fiber, except that the basis weight of the sheet for making the surface fiber was 90 g / m 2 Otherwise, in the same manner as in Example 1, suede-like artificial leather 7 was obtained. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0087] [Example 8] Using the fiber produced in Fiber Production Example 4 (Resin 1, fineness 1.8 dtex, fiber length 5 mm) as the heat-fusing fiber, the weight ratio of the sheet for making the surface fiber was changed to main fiber:heat-fusing fiber = 94:6, and the basis weight of the sheet for making the surface fiber was 80 g / m 2 Otherwise, in the same manner as in Example 1, suede-like artificial leather 8 was obtained. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0088] [Example 9] Using the fiber produced in Fiber Production Example 5 (Resin 2, fineness 1.0 dtex, fiber length 5 mm) as the heat-fusing fiber, the basis weight of the sheet for making the surface fiber was 110 g / m 2 Otherwise, in the same manner as in Example 1, suede-like artificial leather 9 was obtained. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0089] [Example 10] Using the fiber produced in Fiber Production Example 6 (Resin 3, fineness 1.0 dtex, fiber length 5 mm) as the heat-fusing fiber, the basis weight of the sheet for making the surface fiber was 120 g / m 2Except for setting the heat annealing temperature to 165°C, artificial leather 10 with a suede texture was obtained in the same manner as in Example 1. The manufacturing conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0090] [Example 11] Using the fiber (resin 3, fineness 1.8 dtex, fiber length 5 mm) produced in Fiber Production Example 7 as the heat-fused fiber, and setting the basis weight of the surface fiber forming sheet to 110 g / m 2 Except for setting the heat annealing temperature to 165°C, artificial leather 11 with a suede texture was obtained in the same manner as in Example 1. The manufacturing conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0091] [Example 12] Using the fiber (resin 4, fineness 1.0 dtex, fiber length 5 mm) produced in Fiber Production Example 8 as the heat-fused fiber, except for setting the heat annealing temperature to 170°C, artificial leather 12 with a suede texture was obtained in the same manner as in Example 1. The manufacturing conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0092] [Example 13] Using the fiber (resin 4, fineness 1.0 dtex, fiber length 5 mm) produced in Fiber Production Example 8 as the heat-fused fiber, with the ratio of the surface fiber layer being the weight ratio of main fiber:heat-fused fiber = 93:7, except for setting the heat annealing temperature to 170°C, artificial leather 13 with a suede texture was obtained in the same manner as in Example 1. The manufacturing conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0093] [Comparative Example 1] Except for using the fully fused type heat-fusible staple fiber Castle Ben 8000 (manufactured by Unitika Ltd.) with a single fiber fineness of 0.7 dtex and a length of 5 mm as the heat-fused fiber, artificial leather 14 with a suede texture was obtained in the same manner as in Example 1. The manufacturing conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0094] [Comparative Example 2] As the heat-sealing fiber, all-melt type heat-sealing short fiber Castven 8000 (manufactured by Unitika Ltd.) with a single fiber fineness of 1.1 dtex and a length of 5 mm was used, and the basis weight of the surface fiber forming sheet was 110 g / m 2 Except for the above, in the same manner as in Example 1, suede-like artificial leather 15 was obtained. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0095] [Comparative Example 3] As the heat-sealing fiber, all-melt type heat-sealing short fiber Melty 4080 (manufactured by Unitika Ltd.) with a single fiber fineness of 2.2 dtex and a length of 5 mm was used, and the basis weight of the surface fiber forming sheet was 110 g / m 2 Except for the above, in the same manner as in Example 1, suede-like artificial leather 16 was obtained. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0096] [Comparative Example 4] As the heat-sealing fiber, the fiber produced in Fiber Production Example 9 (Pebax 6333SP-01, short fiber fineness 1.0 dtex, fiber length 5 mm) was used, and the basis weight of the surface fiber forming sheet was 110 g / m 2 Except for setting the heat annealing temperature to 180°C, in the same manner as in Example 1, suede-like artificial leather 18 was obtained. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0097] [Comparative Example 5] As the heat-sealing fiber, the fiber produced in Fiber Production Example 10 (Resin 1, fineness 5.0 dtex, fiber length 5 mm) was used, and the basis weight of the surface fiber forming sheet was 140 g / m 2 Except for the above, in the same manner as in Example 1, suede-like artificial leather 19 was obtained. The production conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0098] [Comparative Example 6] As the heat-sealing fiber, except for using the core-sheath type composite heat-sealing short fiber Castle Ben 8080 (Unitika Ltd. 2.2T5-8080 type) with a single fiber fineness of 2.2 dtex and a length of 5 mm, where the sheath part is made of polyethylene terephthalate copolymer with a melting point of 181°C and the core part is made of polyethylene terephthalate monopolymer with a melting point of 255°C, artificial leather 20 with a suede texture was obtained in the same manner as in Example 1. The manufacturing conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0099] [Comparative Example 7] Except that the temperature of heat annealing was set to 130°C, artificial leather 21 with a suede texture was obtained in the same manner as in Example 3. The manufacturing conditions and evaluation results of the obtained artificial leather are shown in Table 1 below.

[0100]

Table 1

Industrial Applicability

[0101] The artificial leather of the present invention is excellent in texture and has high abrasion resistance. Further, if the main fiber and the thermoplastic fiber used in the artificial leather of the present invention are polyester-based fibers and do not contain an elastic polymer such as aqueous polyurethane, it will be excellent in recyclability. Furthermore, the artificial leather of the present invention can be suitably used not only as a car interior material but also in fields such as seat skin materials and interior materials for railway vehicles, aircraft, ships, clothing, shoes, bags, smartphone cases, interiors, and furniture.

Explanation of Symbols

[0102] 1 Main fiber 2 Massive resin 3 Unmelted resin (heat-sealing fiber) 4 Sheath-core fiber

Claims

1. An artificial leather comprising at least a surface fiber layer constituting a first surface, having the following characteristics: (1) The surface fiber layer contains a main fiber and a thermoplastic resin; (2) The fineness of the main fiber is 0.01 dtex or more and 0.5 dtex or less; (3) At least a part of the thermoplastic resin adheres between the main fibers; The number average volume of the thermoplastic resin in the surface fiber layer is 3500 μm 3 or more and 24000 μm 3 or less; and (5) The thermoplastic resin is a copolymer of polyester and aliphatic polyether; having, and the volume number density of the thermoplastic resin in the surface fiber layer is 0.5×10^12 pieces / m^3 or more and 5.0×10^12 pieces / m^3 or less, and the presence ratio (%) of the soft segment of the copolymer is 40% or more and 85% or less, the artificial leather.

2. The artificial leather according to Claim 1, wherein the main fiber is a polyester fiber.

3. The artificial leather according to Claim 1 or 2, wherein the thermoplastic resin is a copolymer of polybutylene phthalate and aliphatic polyether.

4. The artificial leather according to Claim 3, wherein the thermoplastic resin is a copolymer of polybutylene phthalate and polytetramethylene ether glycol.

5. The artificial leather according to any one of Claims 1 to 4, wherein the surface fiber layer is entangled with a scrim layer which is a woven fabric.

6. The artificial leather according to Claim 5, wherein the scrim layer is made of polyester resin fibers.

7. The artificial leather according to any one of Claims 1 to 6, wherein the average value of the quotient obtained by dividing the major axis by the minor axis when the thermoplastic resin in the surface fiber layer is approximated by an ellipse is 100 or less.

8. According to JIS-L-1096 E method (Martindale method), when the surface is worn under a pressing load of 12 kPa, the scrim does not expose when the number of wear times is less than 50,000 times. The artificial leather according to any one of Claims 1 to 7.

9. According to JIS-L-1096 E method (Martindale method), when the surface is worn under a pressing load of 12 kPa, the wear loss at 50,000 wear times is 21 mg or less. The artificial leather according to any one of Claims 1 to 8.

10. The following steps: (1) Mixing a main fiber and a heat-fusible fiber made of a thermoplastic resin containing a copolymer of polyester and aliphatic polyether so that the weight ratio of the heat-fusible fiber is 3% or more and 25% or less, entangling them by wet papermaking, and then forming a surface fiber web by a water stream entangling treatment or a needle punching method; and (2) Forming a surface fiber layer by thermal annealing the entangled structure of the obtained surface fiber web at a temperature equal to or higher than the melting point of the heat-fusible fiber and lower than the melting point of the main fiber; The method for manufacturing artificial leather according to any one of claims 1 to 9, which has the above steps.

11. The method according to claim 10, wherein the flexural modulus of the thermoplastic resin is 40 MPa or more and 200 MPa or less.

12. The method according to claim 10 or 11, wherein the fiber length of the heat-fusible fiber made of the thermoplastic resin is 2 mm or more and 90 mm or less.

13. The method according to any one of claims 10 to 12, wherein the fiber diameter of the heat-fusible fiber made of the thermoplastic resin is 0.5 dtex or more and 2.2 dtex or less.

14. The method according to any one of claims 10 to 13, wherein the heat-fusible fiber made of the thermoplastic resin is manufactured by melt spinning.

15. The method for manufacturing artificial leather according to any one of claims 10 to 14, wherein 95% by weight or more of the thermoplastic resin is a copolymer of polyester and aliphatic polyether.

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