Artificial leather, vehicle interior material, and seat

Abstract

To provide an artificial leather that has high-quality appearance, and is thin, highly strong, and flexible so as to be easily molded along a shape.SOLUTION: An artificial leather includes, as a main component, fibers including a polyester-based resin as a primary component. The fibers are long fibers. The average single fiber diameter of the fibers is 2.0 μm or more and 7.0 μm or less. The fibers are crimped fibers having curvature of 5 to 20%. The fibers are dispersed as single fibers in the artificial leather.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to artificial leather, and a vehicle interior material and a seat using the artificial leather.

Background Art

[0002] Artificial leather with a surface covered with fine fibers has a beautiful appearance and is used in a wide range of fields such as clothing, furniture, and automotive interior materials. Such artificial leather has been made into a uniform sheet by laminating webs made of staple fibers capable of generating fine fibers with a cross-layer, and high levels of appearance and physical properties have been achieved.

[0003] However, in recent years, there has been an increasing demand for even higher levels of appearance and physical properties, and due to the growing awareness of environmental considerations, simplification of the process has been demanded.

[0004] In addition, in electric vehicles, there are many interiors that are simple and highly designed, and there is a tendency to avoid using natural leather from the perspective of environmental considerations. In addition to ceiling materials and door trims, the adoption of artificial leather in complex-shaped parts such as instrument panels is increasing. Therefore, there is a demand for artificial leather that is easy to mold according to complex shapes and has excellent flexibility and extensibility.

[0005] For example, in Patent Document 1, a sea-island composite fiber capable of expressing fine fibers having a coiled crimp with an average single fiber diameter of 0.1 to 10 μm is entangled with a needle punch to form a sheet, and then subjected to a fibrillation treatment to obtain a fine fiber sheet. After imparting an elastic polymer into the sheet and forming a resin layer on the surface, a heat treatment is performed to develop crimps in the fine fibers, and a silver-attached artificial leather has been proposed.

[0006] In Patent Document 2, a web made of long fibers capable of expressing crimps with an average denier of 0.6 dtex or more and a web made of fibers capable of expressing fine fibers are laminated, entangled and integrated with a needle punch, and after expressing crimps by heat shrinkage and expressing fine fibers by fibrillation treatment, an artificial leather to which a polymer elastic body is imparted has been proposed.

[0007] In addition, Patent Document 3 proposes an artificial leather in which a polymer elastomer is applied to a sheet obtained by entangling a spunbond nonwoven fabric made of side-by-side type ultra-fine fibers made of polytrimethylene terephthalate capable of expressing crimp with a woven or knitted fabric by a water jet punch.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] In the technologies disclosed in Patent Document 1 and Patent Document 2, a process for removing the sea component is required to generate ultra-fine fibers, and the ultra-fine fibers generated from the same sea-island fibers tend to gather to form fiber bundles, making it difficult to obtain a sheet with a uniform appearance in which each fiber is dispersed separately. In addition, since it is difficult to increase the line speed of the needle punch, it is difficult to improve productivity.

[0010] In addition, when an artificial leather is obtained by a process for producing ultra-fine fibers as disclosed in Patent Document 3, etc., in terms of the fact that the process for generating ultra-fine fibers becomes unnecessary, it is considered that the process can be easily simplified compared to conventional artificial leathers. On the other hand, in order to uniformly disperse the fibers in water, it is necessary to shorten the fiber length, and it is difficult to obtain an artificial leather having an elegant and high-class appearance and high physical properties. In addition, since the rigidity of the fibers is low, the fibers are likely to entangle in water, making it difficult to obtain a spunbond nonwoven fabric with a uniform texture.

[0011] Therefore, an object of the present invention is to provide an artificial leather that achieves a high level of compatibility between an elegant and luxurious appearance, a thin and high-strength material, and mechanical properties that are easy to conform to the shape, and to provide a method for manufacturing artificial leather that can reduce the environmental impact while improving productivity.

Means for Solving the Problems

[0012] To solve the above problems, the present invention has the following configuration.

[0013] [1] An artificial leather containing fibers mainly composed of a polyester-based resin as main constituent elements, wherein the fibers are long fibers, the average single fiber diameter of the fibers is 2.0 μm or more and 7.0 μm or less, the fibers are crimped fibers with a curvature of 5 to 20%, and the fibers are dispersed as single fibers.

[0014] [2] The artificial leather according to [1], having pile on at least one surface, and the number of fiber ends observed from a 200 μm × 200 μm field of view of the surface having the pile is 4 or more.

[0015] [3] The artificial leather according to [1] or [2], wherein a resin layer is provided on at least a part of at least one surface.

[0016] [4] The X-ray diffraction intensity I of the (-105) plane measured by wide-angle X-ray calculated by the following formula (1) (-105) and the diffraction intensity ratio Z of the X-ray diffraction intensity I of the (100) plane (100) is 0.002 or more and 0.015 or less, and the artificial leather according to any one of [1] to [3]. Z = I (-105) / I (100) ···(1)

[0017] [5] An interior material for a vehicle using the artificial leather according to any one of [1] to [4].

[0018] [6] A seat using the artificial leather according to any one of [1] to [4].

Effects of the Invention

[0019] According to the present invention, it is possible to obtain artificial leather that is highly productive, has an elegant and luxurious appearance, is thin, has high strength, is flexible, and is easy to conform to shapes. Due to the excellent properties of this artificial leather, it can be particularly suitably used for vehicle interior materials or seats.

Brief Description of the Drawings

[0020]

Figure 1

Embodiments for Carrying Out the Invention

[0021] The present invention will be described in detail below. However, the present invention is not limited to the scope described below as long as it does not exceed the gist thereof, and various modifications are possible without departing from the gist of the present invention.

[0022] [Artificial Leather] The artificial leather of the present invention contains, as a main constituent element, fibers whose main component is a polyester-based resin. "The main component consists of a polyester-based resin" means that the mass ratio of the polyester-based resin in the fiber is 50.0% by mass or more. By having the polyester-based resin as the main component, it is possible to achieve both an elegant and luxurious appearance and mechanical properties at a high level, and to obtain artificial leather with excellent durability. Regarding the mass ratio of the polyester-based resin, preferably 60.0% or more, more preferably 70.0% or more, so as to obtain artificial leather without uneven dyeing due to differences in the resin. Also, "containing as a main constituent element" the fibers means that, in the portion excluding the layer bonded to the back surface of the artificial leather described later and the polyurethane, the fibers are contained at a mass ratio of 50.0% by mass or more.

[0023] Examples of the polyester resin include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polylactic acid, and polyester elastomer. Among these, polyethylene terephthalate and polybutylene terephthalate are more preferable from the viewpoints of the texture and practical performance of the processed products, and particularly, polyethylene terephthalate is preferably used.

[0024] For the polyester resin or the resin for expressing the crimp described later, additives may be added within a range that does not inhibit the object of the present invention according to various purposes. Examples of the additive include inorganic particles such as titanium oxide particles, lubricants, pigments, heat stabilizers, ultraviolet absorbers, conductive agents, heat storage agents, antibacterial agents, and the like.

[0025] In addition, in order for the fiber to be the crimped fiber described later, the fiber is preferably composed of conjugate fibers such as a side-by-side type or an eccentric core-sheath type in which two or more resins having different shrinkage rates and viscosities of the resin are laminated. By being a fiber in such a mode, a crimp structure can be expressed by utilizing the shrinkage rate difference with respect to heat treatment. In addition, since the spinnability is good, it is preferable to use latent crimped fibers obtained by laminating resins having different shrinkage rates with respect to heat treatment.

[0026] Examples of the resin combined with the polyester resin to express the crimp include copolymerized polyester and resins other than the polyester resin.

[0027] Examples of the copolymer components of the copolyester include, as the dicarboxylic acid component, aromatic dicarboxylic acids such as isophthalic acid and 2,6-naphthalenedicarboxylic acid; aliphatic dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, sebacic acid, and undecanedicarboxylic acid; and alicyclic dicarboxylic acids such as hexahydroterephthalic acid. Examples of the glycol component include aliphatic glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, and hexamethylene glycol; and aromatic glycols such as bisphenol, 1,3-bis(2-hydroxyethoxy)benzene, and 1,4-(hydroxyethoxy)benzene. One or more of these can be used.

[0028] Examples of resins other than the polyester resin include olefin resins such as polyethylene and polypropylene, and polyamide resins such as nylon 6, nylon 10, nylon 11, nylon 12, nylon 66, and nylon 610, which can be used.

[0029] The difference in intrinsic viscosity between the polyester resin and the resin combined therewith is preferably in the range of 0 to 0.20, more preferably in the range of 0 to 0.15, and even more preferably in the range of 0 to 0.10. By doing so, the bending due to the viscosity difference of the resin discharged from the die is suppressed, and the spinnability becomes good.

[0030] The composite ratio of the crimped fiber by the combination of the polyester resin and the olefin resin or the polyamide resin is preferably 50 to 70%, more preferably 50 to 65%, and even more preferably 50 to 60%. By setting it within this range, an artificial leather with an elegant appearance and good touch can be obtained.

[0031] The fiber is a long fiber. In the present invention, the "long fiber" means a substantially continuous fiber having a fiber length of 100 mm or more, which is not a short fiber intentionally cut after spinning. For example, a short fiber intentionally cut so that the fiber length is about 3 mm to 80 mm is not a "long fiber". However, in the process of manufacturing artificial leather, after a polyester resin and a thermoplastic elastomer resin are spun into a sheet shape, parts where the fiber is cut, for example, fibers at the end formed by slitting the sheet, or surface fibers generated by the formation of raised hairs on the surface of the sheet, etc., even if they are cut to a certain length, the fiber shall be regarded as a long fiber. By the fiber being a long fiber, not only is high strength easily obtained, but also the fiber is less likely to come out of the artificial leather, and the abrasion resistance is good.

[0032] The average single fiber diameter of the fiber is 2.0 μm or more and 7.0 μm or less. By being within this range, a soft and smooth touch can be obtained, the form of the non-woven fabric is stable, and the handleability is good. By the average single fiber diameter of the fiber being 2.0 μm or more, preferably 2.5 μm or more, more preferably 3.0 μm or more, the form stability of the artificial leather can be made higher. On the other hand, by the average single fiber diameter of the fiber being 7.0 μm or less, preferably 6.0 μm or less, more preferably 5.0 μm or less, the artificial leather can be made softer.

[0033] The average single fiber diameter (μm) can be obtained by the following procedure. (1) Cut out 5 test pieces of 2 cm × 2 cm. (2) Photograph the cross-section of the test piece using a scanning electron microscope (for example, "VHX-D510 type" manufactured by KEYENCE CORPORATION). (3) Randomly select 20 circular or nearly circular elliptical fibers. (4) Measure the diameters of 20 single fibers. (5) Perform steps (2) to (4) on all test pieces, and round off the arithmetic mean value (μm) of the obtained single fiber diameters to the third decimal place.

[0034] The fiber is a crimped fiber with a curvature of 5.0 to 20.0%. When the artificial leather is bent, the bent portion of the fiber extends and does not break because the curvature of the fiber is within this range, resulting in a soft texture. When the curvature is 5.0% or more, preferably 6.0% or more, more preferably 7.0% or more, the texture becomes softer. On the other hand, when the curvature is 20.0% or less, preferably 18.0% or less, more preferably 16.0% or less, the tensile strength of the artificial leather can be increased.

[0035] The curvature (%) can be obtained by the following procedure. (1) Slice the central portion in the thickness direction of the artificial leather substrate. (2) Photograph the surface of the slice using a scanning electron microscope (e.g., "VHX-D510 type" manufactured by KEYENCE CORPORATION) at a magnification of 300 times. (3) Randomly select 20 fibers. (4) As shown in FIG. 1, measure the length of a chord S of 100 μm parallel to the baseline B in contact with two bent portions opposing the vertex A in the bent portion of the fiber and the distance L between the vertex A, and calculate the curvature using the following formula. Curvature (%) = L (μm) / 100 (μm) × 100 (5) Obtain the curvature for all 20 fibers, and round the arithmetic mean value (μm) of the obtained values to the second decimal place.

[0036] Further, the fibers are dispersed as single fibers. In the present invention, the fibers being "dispersed as single fibers" means that there is no state in which a fiber bundle is present on the surface where a large number of fibers gather and become thick fibers. This state can be confirmed by observing with a stereomicroscope or an electron microscope. Specifically, a randomly selected area of 1 cm × 1 cm is observed, and the number of fiber bundles in which 10 or more fibers gather and continue over a length of 1 mm or more is counted. If the average value of the number of fiber bundles counted in 10 areas is 3 or less, it is determined that the fibers are "dispersed as single fibers". By the fibers being dispersed as single fibers, the entire artificial leather has a uniform structure, and an appearance with a high-class feeling can be obtained.

[0037] Generally, in artificial leather using ultrafine fiber-generating fibers, due to the formation of structures such as entanglement as ultrafine fiber-generating fibers, in the ultrafine fiber generation process, a plurality of ultrafine fibers in the ultrafine fiber-generating fibers form fiber bundles. When the structure is formed by such fiber bundles, since there is a tendency to form an entanglement part and a surface depending on the size of the fiber bundles, it is difficult to easily obtain a uniform structure as expected in the present invention. Furthermore, in some cases, when rubbed with a finger, the direction of the hair changes and it may look like the color has changed, and it may not be possible to obtain a lighting effect and may be inferior in quality.

[0038] In addition, even if a structure in which the fibers are entangled in a fiber bundle state is included in a part of the artificial leather due to manufacturing constraints or the like, it is acceptable as long as the effects of the present invention are not impaired.

[0039] The artificial leather of the present invention is preferably an artificial leather further containing polyurethane as a constituent element. By containing the polyurethane, it becomes easy to adjust the texture and physical properties. As the polyurethane, a polyurethane obtained by the reaction of a polymer diol, an organic diisocyanate, and a chain extender is preferably used.

[0040] As the polymer diol, for example, at least one polymer diol selected from polymer diols such as polyester diol, polyether diol, polycarbonate diol, or polyester polyether diol can be used. Among them, it is preferable to include a polyether diol or a polycarbonate diol that is excellent in hydrolysis resistance and in which polyurethane is less likely to lose its function as a binder against repeated washing.

[0041] In addition, as the weight average molecular weight of the polymer diol, it is preferably 500 or more and 3,000 or less because when made into polyurethane, it is less likely to lose its function as a binder against repeated washing and is excellent in hydrolysis resistance.

[0042] In addition, various additives can be contained in the polyurethane according to the purpose, for example, pigments such as carbon black, flame retardants such as phosphorus-based, halogen-based and inorganic-based, antioxidants such as phenol-based, sulfur-based and phosphorus-based, ultraviolet absorbers such as benzotriazole-based, benzophenone-based, salicylate-based, cyanoacrylate-based and oxalic acid anilide-based, light stabilizers such as hindered amine-based and benzoate-based, hydrolysis resistance stabilizers such as polycarbodiimide, plasticizers, antistatic agents, surfactants, coagulation regulators and dyes.

[0043] Generally, the content ratio of polyurethane in artificial leather can be appropriately adjusted in consideration of the type of polyurethane used, the manufacturing method of polyurethane, and the texture and physical properties of the desired artificial leather. However, in the artificial leather of the present invention, the content ratio of the polyurethane is preferably 5% by mass or more and 20% by mass or less. By setting the content ratio of the polyurethane to 5% by mass or more, more preferably 8% by mass or more, the abrasion resistance of the artificial leather can be improved. On the other hand, by setting the content ratio of the polyurethane to 20% by mass or less, more preferably 15% by mass or less, and still more preferably 12% by mass or less, the artificial leather can be made more flexible.

[0044] The content ratio of polyurethane in artificial leather can be measured and calculated by the following procedure. (1) Cut out five test pieces of 2 cm × 2 cm and measure the mass of the test pieces. When cutting out test pieces from a product made of artificial leather, randomly collect them from the part excluding the seams and embossed parts of the product, and use them after adjusting to the standard state of a temperature of 20 ± 2°C and a relative humidity of 65 ± 4%. (2) Immerse the artificial leather in a solvent that elutes ultrafine fibers and reinforcing fibers, or a solvent that elutes polyurethane, and calculate the content (g) of polyurethane from the mass change before and after elution. For example, in the case of artificial leather containing organic solvent-based polyurethane, in many cases, the artificial leather is immersed in N,N'-dimethylformamide, and after dissolving and removing the polyurethane, the mass of the remaining ultrafine fibers and reinforcing fibers is measured to calculate the content (g) of polyurethane. (3) Divide the content of polyurethane obtained in (2) by the mass (g) of the test piece obtained in (1) to calculate the content ratio (mass%) of polyurethane. (4) Perform (2) to (3) for all test pieces, calculate the arithmetic mean value (mass%) of the obtained content ratios (mass%) of polyurethane, and round it to the first decimal place.

[0045] In a first preferred embodiment, the artificial leather of the present invention has raised hairs on at least one surface, and the number of fiber ends observed from a 200 μm × 200 μm field of view of the surface having the raised hairs is preferably 4 or more. By having the raised hairs on the artificial leather, a writing effect can be exhibited. The larger the number of the ends, the larger the number of raised hairs. By setting the number of the ends to preferably 4 or more, more preferably 7 or more, and even more preferably 10 or more, it can be used as an artificial leather having a beautiful suede-like or nubuck-like appearance.

[0046] The number of the ends can be measured by the following procedure. (1) Cut out five test pieces of 2 cm × 2 cm. (2) Photograph the cross-section of the test piece three times each at a magnification of 500 times using a scanning electron microscope (for example, "VHX-D510 type" manufactured by KEYENCE CORPORATION). (3) Randomly extract a 200 μm square field of view from the photographed images and count the number of fiber ends. (4) Calculate the arithmetic mean value (pieces) of the number of fiber ends obtained from all the photographed images and round it to the first decimal place.

[0047] Further, as a second preferred embodiment, it is also preferable that the artificial leather of the present invention has a resin layer provided on at least a part of at least one surface. For example, by providing the resin layer having a pattern such as a natural leather-like texture on the surface of the artificial leather, a so-called silver surface artificial leather can be obtained.

[0048] As the resin for forming the resin layer, for example, a polyurethane resin is preferable. Examples of the polyurethane resin include polyurethane resins such as polyether-based, polyester-based, polycarbonate-based, and acrylic-based, and they can be used alone or in combination of two or more. The polyurethane resin may be any of a solventless type (solvent-free type), a hot melt type, a solvent type, or an aqueous type, and may be either a one-component type or a two-component curing type.

[0049] When the thickness of the resin layer is 30 μm or more and 200 μm or less, it is likely to achieve both the texture and abrasion resistance of the artificial leather, so it is preferable. More preferably, it is 30 μm or more and 180 μm or less, and even more preferably, it is 50 μm or more and 150 μm or less.

[0050] The thickness of the resin layer can be calculated by photographing a scanning electron microscope (SEM) photograph of the cross-section of the artificial leather, randomly measuring the thickness of the resin layer at 10 locations, calculating the arithmetic mean value (μm), and rounding it to the first decimal place.

[0051] Also, an embodiment in which the first preferred embodiment and the second preferred embodiment are simultaneously implemented on the same surface is also preferred. Specifically, so-called semi-silver artificial leather, that is, artificial leather in which a resin layer is discretely provided on a surface having raised hairs, is exemplified. Here, "discretely provided with a resin layer" means a form in which the resin layer is arranged in a lattice pattern, a staggered pattern, a twill pattern, a crepe pattern, a random pattern, etc. in the shapes described later. Further, as the shape of the resin layer, various shapes such as a circle, a star, a heart, and polygons such as a triangle, a square, a hexagon, and an octagon can be used according to the application. Of course, in the present invention, the arrangement form and shape when discretely providing the resin layer are not particularly limited.

[0052] In the artificial leather of the present invention, the X-ray diffraction intensity I of the (-105) plane measured by wide-angle X-ray calculated by the following formula (1) (-105) and the X-ray diffraction intensity I of the (100) plane (100) It is preferable that the diffraction intensity ratio Z is 0.002 or more and 0.015 or less. Z = I (-105) / I (100) ···(1) Here, the X-ray diffraction intensity I of the (-105) plane (-105) means the fiber orientation ratio in the thickness direction, and the X-ray diffraction intensity I of the (100) plane (100) means the fiber orientation ratio in the plane direction.

[0053] When Z is 0.002 or more, more preferably 0.004 or more, and even more preferably 0.005 or more, the morphological stability of the artificial leather is improved and the process passability is high. On the other hand, when Z is 0.015 or less, more preferably 0.012 or less, and even more preferably 0.010 or less, the tensile strength becomes higher.

[0054] Generally, when manufacturing the base material of artificial leather, fibers are oriented in the thickness direction of the base material by methods such as needle punching or high-pressure water flow treatment. However, the more the orientation in the thickness direction is increased by these methods, the lower the production speed, the greater the amount of energy consumed, and the greater the environmental impact. On the other hand, by making the direction in which the fibers are aligned more in the plane direction than in the thickness direction, the tensile strength can be higher even with the same basis weight, so it is possible to make a thin and high-strength artificial leather.

[0055] (-105) plane X-ray diffraction intensity I (-105) and (100) plane X-ray diffraction intensity I (100) The diffraction intensity ratio Z is measured and calculated by the following procedure. (1) Cut out a test piece of 1.5 cm × 1.5 cm and place it on a Si non-reflecting plate. (2) Use a CuKα ray as the X-ray source and perform a 2θ-θ continuous scan (2θ = 5° to 60°, step width 0.01711°, scan speed 0.5 seconds / step) with an output of 40 kV, 40 mA, and a slit system DS = 0.3°. (3) Calculate the crystal size L from the diffraction peak by the following formula. Crystal size L [nm] = Kλ / ((β e 2 - β0 2 ) 1 / 2 × COSθ) λ: X-ray wavelength (0.15418 nm), β e : Half-value width of the diffraction peak, β0: Correction value of the half-value width (0.13°), K: Scherrer constant (0.9). (4) From the (-105) plane X-ray diffraction intensity I (-105) obtained from the diffraction peak and the (100) plane X-ray diffraction intensity I (100) , calculate the diffraction intensity ratio Z by the following formula (1) and round it off to the fourth decimal place. Diffraction intensity ratio Z = I (-105) / I (100) ···(1).

[0056] In addition, in order to obtain higher strength characteristics, the artificial leather of the present invention preferably includes a layer made of reinforcing fibers as a constituent element. The average single fiber diameter of the reinforcing fibers is preferably 5.0 μm or more and 25.0 μm or less.

[0057] The average single fiber diameter of the reinforcing fibers can be calculated by taking a scanning electron microscope (SEM) photograph of the cross-section of the artificial leather, randomly selecting 10 of the reinforcing fibers constituting the layer made of the reinforcing fibers, measuring the single fiber diameter of the fibers, calculating the arithmetic mean value (μm) of the 10 fibers, and rounding to the second decimal place. However, when fibers with a non-circular cross-section are used, in the same manner as in the case of measuring and calculating the average single fiber diameter of the fibers constituting the artificial leather, first measure the cross-sectional area (μm 2 ) of the fiber, and obtain the diameter of the fiber (μm), that is, the equivalent circular diameter, by calculating the diameter when the cross-section is regarded as circular. Further, when the reinforcing fiber is a multifilament as described later, the diameter of the single fiber constituting the multifilament is taken as the average single fiber diameter of the reinforcing fiber.

[0058] [Method for manufacturing artificial leather] The method for manufacturing the artificial leather of the present invention preferably comprises melting polyethylene terephthalate, a copolymer polymer of polyethylene terephthalate and polyethylene glycol, a polymer obtained by copolymerizing polyethylene terephthalate, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane, and isophthalic acid, etc., polyester-based resins having different shrinkage rates, or polyethylene terephthalates having different degrees of polymerization, melting them with separate extruders respectively, then merging them in a die so that they can be discharged from the same discharge hole in a side-by-side type or an eccentric core-sheath type bonded form at a single-hole discharge rate of 0.025 g / min or more and 0.30 g / min or less, discharging the polymer, and then spraying a gas at -15°C or more and 50°C or less to form a yarn so as to include at least a part of the region within 200 mm from the discharge hole, and at least at the inlet, pulling the yarn with a gas at -15°C or more and 50°C or less so that the spinning speed is 3,000 m / min or more and 7,000 m / min or less, to obtain a web composed of crimped fibers or latent crimped fibers having a main component of a polyester-based resin and an average single fiber diameter of 2.0 μm or more and 7.0 μm or less.

[0059] Here, the "inlet" is the place where the wind speed of the gas for pulling is the highest between the discharge hole and obtaining the web. Generally, it is the place where the cross-sectional area of the passage through which the resin discharged from the discharge hole becomes a yarn is the smallest between the discharge hole and obtaining the web. Hereinafter, the details of this manufacturing method will be described. Of course, also in this part, the present invention is not limited to the scope described below as long as it does not exceed the gist, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[0060] First, it is preferable to merge and discharge the molten polyester-based resins inside the die so that they can be discharged in a side-by-side bonded form from the same discharge hole at a single-hole discharge rate of 0.025 g / min or more and 0.30 g / min or less. In the present invention, the single-hole discharge rate (g / min) refers to the discharge amount (g) of the resin discharged from one discharge hole (single hole) of the die per unit time (min). Regarding the lower limit of the range of this single-hole discharge rate, preferably 0.05 g / min or more, more preferably 0.07 g / min or more, and even more preferably 0.09 g / min or more, stable spinnability can be obtained within the range of the spinning speed described later. On the other hand, regarding the upper limit of the range of the single-hole discharge rate, preferably 0.30 g / min or less, more preferably 0.25 g / min or less, and even more preferably 0.20 g / min or less, fibers with an average single fiber diameter of 7.0 μm or less, from which artificial leather with an elegant appearance can be obtained, can be easily obtained within the range of the spinning speed described later.

[0061] At this time, the pore diameter of the discharge hole is preferably 0.05 mm or more and 0.30 mm or less. Regarding the lower limit of the range of the pore diameter, preferably 0.05 mm or more, more preferably 0.07 mm or more, and even more preferably 0.09 mm or more, it is possible to suppress the decrease in spinnability over time due to the adhesion of dirt or the like. On the other hand, regarding the upper limit of the range of the pore diameter, preferably 0.30 mm or less, more preferably 0.25 mm or less, and even more preferably 0.20 mm or less, a stable spinning state can be easily obtained. In the present invention, when the discharge hole is not a perfect circle, the diameter of the perfect circle (equivalent circle diameter) with the same hole area is referred to as the pore diameter.

[0062] After discharging the molten resin from the discharge hole of the die, it is preferable to form a filament by blowing a gas at -15°C or higher and 50°C or lower so as to include at least a part of the region within 200 mm from the discharge hole. Generally, since it is likely to affect the temperature of the discharge hole and destabilize the spinning, it is usually avoided to blow the gas at a position close to the discharge hole. However, as a result of the study by the present inventors, it has been found that in the spinning for obtaining ultrafine fibers, the spinning is stabilized by blowing the gas at a position close to the discharge hole.

[0063] Regarding the lower limit of the temperature range of the gas, preferably it is -15°C or higher, more preferably -10°C or higher, and even more preferably -5°C or higher, so that it is possible to prevent the temperature in the vicinity of the discharge hole from decreasing excessively. On the other hand, regarding the upper limit of the temperature range of the gas, preferably it is 50°C or lower, more preferably 40°C or lower, and even more preferably 30°C or lower, so that the discharged resin can be sufficiently cooled.

[0064] In addition, the region where the gas is blown is preferably made to include at least a part of the region within 200 mm from the discharge hole, more preferably made to include at least a part of the region within 150 mm from the discharge hole, and even more preferably made to include at least a part of the region within 100 mm from the discharge hole. By doing so, it becomes easier to obtain fibers of 7.0 μm or less which are usually difficult to obtain, and artificial leather with an excellent appearance can be obtained.

[0065] In addition, examples of the gas supply means used for blowing the gas include a method of supplying the gas from one or multiple directions of the discharged resin through a slit nozzle or a rectifying unit to a blower.

[0066] And it is preferable that the distance between the discharge hole and the inlet is 100 mm or more and 3,000 mm or less. Regarding the lower limit of the distance range between the discharge hole and the inlet, preferably 100 mm or more, more preferably 200 mm or more, and still more preferably 300 mm or more, the fibrillation of the molten resin can be sufficiently promoted, and stable spinning can be more easily performed. On the other hand, regarding the upper limit of the distance range between the discharge hole and the inlet, preferably 3,000 mm or less, more preferably 2,000 mm or less, and still more preferably 1,000 mm or less, the yarns made of the resin discharged from the plurality of discharge holes can be stably guided to the inlet.

[0067] Furthermore, it is preferable that the yarn is made to have a spinning speed Vs (m / min) of 3,000 m / min or more and 7,000 m / min or less, at least at the inlet. Regarding the lower limit of the range of the spinning speed Vs (m / min), preferably 3,000 m / min or more, more preferably 3,500 m / min or more, and still more preferably 4,000 m / min or more, the molecular orientation of the fiber becomes sufficient and has an appropriate firm touch, and artificial leather excellent in mechanical physical properties and morphological stability can be obtained. On the other hand, regarding the upper limit of the range of the spinning speed Vs (m / min), preferably 7,000 m / min or less, more preferably 6,500 m / min or less, and still more preferably 6,000 m / min or less, the yarn sprayed with the gas can be more stably drawn.

[0068] The spinning speed Vs (m / min) is measured and calculated by the following method. (1) After pulling and stretching the yarn, 10 small piece samples are randomly collected from the web collected on the net, surface photos at 500 to 1,000 times magnification are taken with a microscope, and the widths of 10 fibers are measured for each of the 10 fibers, a total of 100 fibers, and the single fiber diameter (μm) is calculated from their arithmetic mean value. (2) From the single fiber diameter and the density of the resin used at 20°C, the mass per 10,000 m in length is calculated as the single fiber fineness (dtex), rounding off the second decimal place. (3) Based on the single fiber fineness (dtex) of (2) and the single-hole discharge amount (g / min) set under each condition, calculate the spinning speed according to the following formula and round it to the first decimal place. Spinning speed (m / min) = (10,000 × single-hole discharge amount (g / min)) / single fiber fineness (dtex).

[0069] Also, regarding the lower limit of the temperature range of the gas used when drawing the yarn, preferably it is -15°C or higher, more preferably -10°C or higher, and even more preferably -5°C or higher, so that the yarn can be cooled uniformly. On the other hand, regarding the upper limit of the temperature range of the gas, preferably it is 50°C or lower, more preferably 40°C or lower, and even more preferably 30°C or lower, so that the yarn can be cooled sufficiently.

[0070] Furthermore, the ratio Vq / Vs of the gas flow rate Vq (m / min) to the spinning speed Vs (m / min) when spraying the gas is 3×10 -3 or more and 30×10 -3 or less is preferable. Regarding the lower limit of the range of Vq / Vs, preferably it is 3×10 -3 or more, more preferably 4×10 -3 or more, and even more preferably 5×10 -3 or more, so that the yarn can be cooled sufficiently. On the other hand, the upper limit of the range of Vq / Vs is preferably 30×10 -3 or less, more preferably 20×10 -3 or less, and even more preferably 10×10 -3 or less, so that the yarn can be drawn more stably.

[0071] By the above method, a web composed of fibers with an average single fiber diameter of 2.0 μm or more and 7.0 μm or less can be obtained. And further, in the method for manufacturing the artificial leather of the present invention, for example, it is preferable to perform at least one of the following steps for manufacturing. (1) Step of obtaining a sheet substrate in which the fibers of the web are entangled (2) Step of shrinking the latent crimped fibers of the web or the sheet substrate by dry heat treatment to obtain a crimped sheet substrate (3) Applying polyurethane to the sheet substrate or the crimped sheet to obtain a sheet substrate with polyurethane (4) Performing a raising treatment on at least one surface of any one of the sheet substrate, the crimped sheet substrate, or the sheet substrate with polyurethane to form raised hairs on the surface and form a raised hair sheet (5) Providing a resin layer made of polyurethane on at least a part of at least one surface of any one of the sheet substrate, the crimped sheet substrate, the sheet substrate with polyurethane, or the raised hair sheet to obtain a resin layer forming sheet (6) Performing post-processing on any one of the raised hair sheet or the resin layer forming sheet

[0072] Note that when the above (2) and (4), or (2) to (4) are performed, the raised hair sheet becomes artificial leather. And when (2) and (5), or (2) to (3) and (5), (2) to (5) are performed, the resin layer forming sheet becomes artificial leather. Needless to say, what is obtained through the process of (6) also becomes artificial leather. Details of each process will be further described below.

[0073] First, in the process of obtaining the sheet substrate, methods such as entangling fibers by laminating a single web layer or multiple layers to a desired basis weight and then performing needle punching or water jet punching can be adopted.

[0074] Next, in the process of obtaining the crimped sheet substrate, as heat treatment means, methods such as blowing hot air, contacting with a heated roll, or pressing the web in multiple stages by a plurality of flat rolls with different temperatures to perform heat treatment at a temperature equal to or higher than the glass transition point and lower than the melting point of the resin constituting the fibers can be adopted.

[0075] Next, in the step of obtaining the sheet substrate with polyurethane, a method of dissolving polyurethane or its precursor in a solvent (solvent method), such as N,N'-dimethylformamide or dimethyl sulfoxide, is preferably used. However, a method of using an aqueous dispersion type polyurethane liquid in which a mixture containing at least a polymer diol, an organic diisocyanate, and a chain extender, that is, polyurethane or its precursor, is dispersed as an emulsion in water (aqueous dispersion method) is also preferably used. In the case of the former solvent method, for example, after immersing the heat-treated sheet substrate in the polyurethane solution and then drying, a method of substantially coagulating and solidifying the polyurethane precursor, or a method of immersing the heat-treated sheet substrate in the polyurethane solution and then immersing it in another solvent in which polyurethane is insoluble to cause coagulation can be adopted. On the other hand, in the case of the latter aqueous dispersion method, for example, after immersing the heat-treated sheet substrate in the aqueous dispersion type polyurethane liquid, it can be coagulated by a dry coagulation method or the like followed by drying. When drying, heating can be performed at a temperature that does not impair the performance of the heat-treated sheet substrate or the sheet substrate with polyurethane.

[0076] And in the step of forming the raised hair sheet, the raising treatment performed on at least one surface such as the heat-treated sheet substrate can be carried out using sandpaper, a roll sander, or the like. Among them, by using sandpaper, uniform and dense raised hair can be formed. In particular, in order to form uniform raised hair on the surface of the web or the like, it is preferable to reduce the grinding load in the raising treatment. As a specific means for reducing the grinding load, for example, it is a more preferable embodiment that the buffing has three or more stages and the grit number of the sandpaper used in each stage is in the range of 120 (P120) to 600 (P600) defined in JIS R 6010:2000 "Grain size of abrasives for abrasive papers".

[0077] Also, in the step of forming the resin layer, a one-component polyurethane resin colored with a pigment is coated on the mold-pressed release paper and dried in an oven. Next, a two-component polyurethane resin is coated as an adhesive and dried again in the oven, and the resin layer is laminated to the heat treatment sheet substrate or the like. After the reaction is completed, the release paper is peeled off. Another method is to directly coat the surface of the heat treatment sheet substrate or the like with polyurethane dissolved in a solvent such as N,N'-dimethylformamide or dimethyl sulfoxide, immerse it in another solvent in which polyurethane is insoluble and solidify it, then wash with water and dry, and then laminate it to the resin layer formed on the above-mentioned release paper.

[0078] As a method of forming a resin layer on the surface of artificial leather using a polymer elastomer such as polyurethane, there are methods of applying a resin liquid containing the polymer elastomer to the surface of the artificial leather and curing it, and methods of forming a resin layer containing the polymer elastomer on a support substrate such as release paper, then applying an adhesive to the surface of the resin layer and laminating it to the surface of the artificial leather.

[0079] Also, as a method of discretely providing the resin layer, similar to the case of providing the above resin layer, there are methods of applying a polymer elastomer such as polyurethane to the surface of the artificial leather in a desired pattern and curing it, and methods of forming a resin layer on a support substrate such as release paper, then applying an adhesive to the surface of the resin layer and laminating it to the surface of the artificial leather.

[0080] Finally, in the step of performing post-processing, functional agents such as dyes, pigments, softeners, anti-pilling agents, antibacterial agents, deodorants, water repellents, light fastness agents, and weather resistance agents can be contained in the web or the like.

[0081] For example, heat treatment sheet substrates and the like can also be dyed. Specific means for dyeing are not particularly limited. However, since the above-mentioned heat treatment sheet substrates and the like can be softened by adding a rubbing effect while being dyed, a flow-through dyeing machine is preferably used in the same manner as in the case of dyeing conventional artificial leather. In order to dye polyester fibers, the temperature of the dyeing solution during dyeing is preferably 100°C or higher and 150°C or lower. Acid dyes, metal-containing dyes, reactive dyes, etc. are preferably used as dyes. Also, reduction washing can be performed after dyeing.

[0082] Also, for the purpose of improving the uniformity of dyeing, it is also preferable to use a dyeing assistant when performing dyeing. Furthermore, finishing treatments such as softeners such as silicone, antistatic agents, water repellents, flame retardants, and light fastness agents can also be performed. This finishing treatment can be carried out after dyeing or in the same bath as dyeing.

[0083] Alternatively, various perforation processes (perforation processing), embossing, stitching, foil processing, resin printing, inkjet printing, laser etching, bonding knitted fabrics, woven fabrics, films, polyurethane foams, etc. to the back surface of the base material to improve strength and integral moldability can also be carried out together as one of the post-processing steps.

[0084] [Interior material for vehicles, seats] Since the artificial leather of the present invention has the characteristics of being thin, high-strength, and easy to conform to the shape, it is preferably used for all applications including clothing applications, miscellaneous goods applications, footwear applications, interior materials for vehicles, seats, CD curtains, DVD curtains, base materials for polishing pads, various polishing cloths, and wiping cloths, etc.

[0085] Among them, the vehicle interior material made of the above artificial leather is preferable because it can make use of the particularly elegant and luxurious appearance, as well as the characteristics of being thin, high-strength, and easy to conform to the shape. That is, the vehicle interior material of the present invention is made of the artificial leather of the present invention. As such a vehicle interior material, for example, at least a part of a steering wheel, a horn switch, a shift knob, a dashboard, an instrument panel, a glove box, a floor carpet, a floor mat, a ceiling lining, a sun visor, an assist grip, etc. of an automobile is more preferably the above artificial leather. In the present invention, the "vehicle" includes automobiles, airplanes, railway vehicles, ships, as well as vehicles such as carriages, palanquins, and rickshaws, and further includes some industrial machines, construction machines, and agricultural machines that can carry people or animals and move.

[0086] Alternatively, the seat made of the above artificial leather is also preferable because it can make use of the particularly elegant and luxurious appearance, as well as the characteristics of being thin, high-strength, and easy to conform to the shape. That is, the seat of the present invention is made of the artificial leather of the present invention. As such a seat, it is more preferable that at least a part of the skin material such as a headrest, a seat surface, an armrest, a footrest, etc., for example, the part that directly contacts the seated person, is the above artificial leather. Of course, the seat of the present invention can be used not only for vehicles such as automobiles, airplanes, railway vehicles, and ships, but also for household, office, and store seats. In the present invention, the "seat" includes chairs, benches, sofas, couches, stools, and seats.

Examples

[0087] Next, the present invention will be specifically described based on examples. However, the present invention is not limited to only these examples. In the measurement of each physical property, those without special description were measured based on the above method.

[0088] [Measurement method] (1) Average single fiber diameter (μm) of polyester fibers The average fiber diameter (μm) of the polyester fibers contained as the main components in the artificial leather was measured and calculated by the above method using the "VHX-D510 type" manufactured by Keyence Corporation as a scanning electron microscope.

[0089] (2) Dispersion state of fibers in artificial leather In the artificial leather, the evaluation of whether the fibers are dispersed as single fibers or not was carried out by randomly selecting a 1 cm × 1 cm area on the surface of the artificial leather and evaluating it by the above method using the scanning electron microscope "VHX-D510 type".

[0090] (3) Curvature of crimped fibers The crimped fibers contained as the main components in the artificial leather were measured and calculated by the above method using the scanning electron microscope "VHX-D510 type".

[0091] (4) Diffraction intensity ratio Z The diffraction intensity ratio Z of the artificial leather was measured and calculated by the above method using "D8 ADVANCE" manufactured by Bruker Japan Co., Ltd. as an X-ray diffractometer.

[0092] (5) Judgment of surface hairiness Regarding the surface hairiness of the artificial leather, it was evaluated by the above method using the scanning electron microscope "VHX-D510 type".

[0093] (6) Judgment of surface resin layer Regarding the surface resin layer of the artificial leather, it was evaluated by the above method using the scanning electron microscope "VHX-D510 type".

[0094] (7) Basis weight and thickness The basis weight was measured by the method described in JIS L 1096 (2020) 8.3.2. Also, the thickness was measured using a dial thickness gauge (manufactured by Ozaki Seisakusho Co., Ltd., product name "Peacock (registered trademark) H").

[0095] (8) Evaluation of writing effect and flexibility Regarding artificial leather with raised hairs on the surface, artificial leather samples cut into 10 cm × 10 cm were placed with the raised hair surface facing up, and five people proficient in the evaluation of artificial leather served as evaluators for evaluation. Regarding the writing effect where the direction of the hairs changes and the color seems to change when stroked with a finger, and the degree of suppleness when stroking the surface with a finger, each was evaluated according to the following five-level criteria, and the average score was obtained to the first decimal place as the evaluation score. Subsequently, the sum of the evaluation score of the writing effect and the evaluation score of suppleness was taken as the appearance evaluation score of the artificial leather, and a score of 6.0 or more was considered passing. The appearance evaluation of the artificial leather is preferably 7.0 or more, and more preferably 8.0 or more.

[0096] [Evaluation of Writing Effect] ·5 points: The trace of stroking with a finger is clearly visible. ·4 points: The trace of stroking with a finger is visible (midway between 3 points and 5 points). ·3 points: The trace of stroking with a finger is slightly weak but visible. ·2 points: The trace of stroking with a finger is hardly visible without attention (midway between 1 point and 3 points). ·1 point: The trace of stroking with a finger is not visible.

[0097] [Evaluation of Suppleness] ·5 points: A moist and comfortable touch. ·4 points: A smooth touch (midway between 3 points and 5 points). ·3 points: A crisp touch. ·2 points: A slightly rough touch (midway between 1 point and 3 points). ·1 point: Feeling rough.

[0098] For artificial leather with a resin layer formed on at least a part of the surface, an artificial leather sample cut into 10 cm × 10 cm was placed with the nap surface facing up and folded in half. A 6 cm × 6 cm flat plate was placed on top of the folded sample to cover the entire surface, and a load was applied so that the total mass of the flat plate and the weight was 4 kg. After applying the load for 30 seconds, the flat plate and the weight were removed, and 5 evaluators evaluated the state of the wrinkles in the bent part according to the following 5 - level criteria 10 seconds later. The average score was obtained to the first decimal place and used as the evaluation score. Subsequently, the average value of the scores judged by each evaluator was used as the evaluation score, and a score of 2.6 or more was considered a pass. The evaluation score is preferably 3.0 or more, and more preferably 3.6 or more.

[0099] (9) Flexural rigidity Regarding flexural rigidity, as a pure bending testing machine, "KES - FB2 - A" manufactured by Kato Tech Co., Ltd. was used. Three artificial leather samples cut into 10 cm × 10 cm were collected. The sensitivity was SENS = 20, the speed was 0.50 cm -1 / sec, and the measurement curvature was 0.5 - 2.5 cm -1 Bending tests were performed in the MD direction (longitudinal direction) and the CD direction (transverse direction), and the flexural rigidity (g·cm 2 / cm) was calculated. The value of the flexural rigidity was the average value of the MD direction and the CD direction, rounded to the third decimal place.

[0100] (10) Elongation at a load of 5 N / cm and breaking strength per unit area As an index of the formability of artificial leather, in accordance with JIS L 1096(2020)8.14.1 "Tensile strength and elongation" (Method A: Strip method), for the MD direction, with a test piece width of 25 mm, a grip interval of 100 mm, and a tensile speed of 100 mm / min, the elongation at a load of 5 N / cm was measured. Also, the breaking strength was measured as it was, and the value obtained by dividing the breaking strength (N) by the basis weight of the artificial leather (g / m 2 ) was rounded to the third decimal place to obtain the breaking strength normalized per unit area (N / (g / m 2 ).

[0101] [Example 1] (Web formation) Polyethylene terephthalate (homopolymer, intrinsic viscosity: 0.65; hereinafter referred to as "PET") was used as resin component A.

[0102] A copolymerized polyethylene terephthalate with an intrinsic viscosity of 0.67, which has ethylene terephthalate as the main component and copolymerizes 7.1 mol% of IPA and 4.4 mol% of BHPP therein (intrinsic viscosity: 0.67; hereinafter referred to as "copolymerized PET"), was used as resin component B.

[0103] Resin components A and B were each melted by an extruder. With the single-hole discharge rate of resin component A being 0.03 g / min and that of resin component B being 0.03 g / min, they were made to merge in a die so as to be laminated side by side, and discharged from the same circular discharge hole with a hole diameter of 0.20 mm at a single-hole discharge rate of 0.06 g / min.

[0104] At this time, the mass ratio of the polyester resin in the resin of the discharged yarn was 100% by mass. Thereafter, in the region from 50 mm to 500 mm from the above-mentioned discharge hole, while blowing air at 15°C as cooling air at a flow rate of 30.0 m / min, a yarn was formed. In the region below the inlet, the yarn was drawn with air at 15°C so that the spinning speed became 4,000 m / min. Also, the distance between the discharge hole and the inlet was 700 mm. Then, by collecting the drawn yarn on a net conveyor under suction, a latent crimp web made of bimetal fibers with an average single fiber diameter of 3.7 μm was obtained. The fibers were in a state of being dispersed as single fibers.

[0105] (Formation of sheet substrate) Two of the obtained webs were stacked and processed with a water jet punch (hereinafter referred to as "WJP") at pressures of 8 MPa from one side (front side), 8 MPa from the opposite side (back side), 12 MPa from the front side, and 12 MPa from the back side, and then dried with hot air at 100°C to obtain a sheet substrate.

[0106] (Formation of crimped fiber sheet substrate) The obtained sheet substrate was shrunk by hot air treatment at 180°C to obtain a crimped fiber sheet substrate composed of crimped fibers with an average single fiber diameter of 4.3 μm.

[0107] (Formation of a sheet substrate with polyurethane) An aqueous dispersion type polyurethane solution composed of a polyether diol and a diisocyanate was prepared. The above-mentioned crimped fiber sheet substrate was immersed in this aqueous dispersion type polyurethane solution and then dried with hot air at 120°C to obtain a sheet substrate with polyurethane having a polyurethane content ratio of 30% by mass.

[0108] (Formation of a pile sheet) Raising treatment was performed by grinding one side surface of the sheet substrate with polyurethane using sandpaper of No. 320 to form pile on the surface, thereby obtaining a pile sheet.

[0109] (Post-processing) The obtained pile sheet was subjected to post-processing by dyeing at 130°C using a disperse dye in a liquid flow dyeing machine to obtain artificial leather. The evaluation results are shown in Table 1.

[0110] [Example 2] An artificial leather was obtained in the same manner as in Example 1 except that the spinning speed in the formation of the web was 3,300 m / min. The evaluation results are shown in Table 1.

[0111] [Comparative Example 1] (Formation of the web) PET was used as resin component A.

[0112] Only resin component A was melted with an extruder and discharged from a circular discharge hole with a hole diameter of 0.20 mm at a single hole discharge rate of 0.10 g / min.

[0113] Thereafter, in the region from 50 mm to 500 mm from the above-mentioned discharge holes, while blowing air at 15°C as cooling air at a flow rate of 30.0 m / min, a yarn was formed. In the region below the inlet, the yarn was drawn with air at 15°C so that the spinning speed became 4,600 m / min. Also, the distance between the discharge holes and the inlet was 700 mm. Then, by collecting the drawn yarn on a net conveyor under suction, a web made of single-component fibers with an average single fiber diameter of 4.0 μm was obtained. Note that the fibers were in a state of being dispersed as single fibers.

[0114] (Formation of sheet substrate) The obtained two webs were stacked, and were processed with WJP at pressures of 8 MPa from one side (front side), 8 MPa from the opposite side (back side), 12 MPa from the front side, and 12 MPa from the back side, and then dried with hot air at 100°C to obtain a sheet substrate. Using this sheet substrate, an artificial leather was obtained in the same manner as in Example 1 hereinafter. The evaluation results are shown in Table 1.

[0115] [Comparative Example 2] In the formation of the web, the single-hole discharge amount of resin component A was 0.16 g / min, the single-hole discharge amount of resin component B was 0.16 g / min, and the spinning speed was 4,500 m / min. Otherwise, an artificial leather was obtained in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0116] [Comparative Example 3] An artificial leather was obtained in the same manner as in Example 1 except that the spinning speed in the formation of the web was 2,300 m / min. The evaluation results are shown in Table 1.

[0117]

Table 1

[0118] [Example 3] (Formation of resin film) A water-dispersible polyurethane liquid composed of polyether diol and diisocyanate was mixed with a carbon black-based black pigment using a mixer to prepare a resin liquid for forming a resin layer. This resin liquid was applied in a sheet form onto a release paper having an embossed pattern with a matt finish using a comma coater, and then treated at 100 °C for 3 minutes in a dryer to form a non-porous resin film with a thickness of 40 μm.

[0119] (Lamination of resin films) On the surface of the above resin film, a polycarbonate-based polyurethane resin as an adhesive was applied using a comma coater and heated at 100 °C for 1 minute in a dryer. The surface coated with the adhesive was placed on the surface of the same artificial leather as that prepared in Example 1 and pressed to perform pressure bonding and lamination. Then, the release paper was peeled off to obtain an artificial leather having a resin layer formed on its surface. The evaluation results are shown in Table 2.

[0120] [Comparative Example 4] (Formation of resin film) In the same manner as in Example 3, a non-porous resin film with a thickness of 40 μm was formed.

[0121] (Lamination of resin films) The object to which the above resin film was to be laminated was the same artificial leather as that prepared in Comparative Example 1. Otherwise, in the same manner as in Example 3, an artificial leather having a resin layer formed on its surface was obtained. The evaluation results are shown in Table 2.

[0122]

Table 2

[0123] As shown in Table 1, for the artificial leathers having raised hairs on the surface in Examples 1 to 2, they are excellent in surface appearance and touch, have a low bending rigidity used as an index of flexibility, and a high elongation at a load of 5 N / cm and breaking strength per unit area used as indices of formability. Therefore, they have both high formability and high strength of the base material at a high level. On the other hand, for Comparative Examples 1 and 3, although the surface appearance and touch are good, the results show that either the bending rigidity or the elongation at a load of 5 N / cm and the breaking strength are inferior. Also, for Comparative Example 2, the results are inferior in surface appearance and touch.

[0124] Also, as shown in Table 2, for the artificial leather with a resin layer provided on the surface of Example 3, the bending rigidity is low, and the elongation at a load of 5 N / cm and the breaking strength per unit area are high. Therefore, it has both high formability and high substrate strength. On the other hand, in Comparative Example 4, the bending rigidity and the elongation at a load of 5 N / cm were high, and the formability was poor.

Explanation of Reference Signs

[0125] A: Vertex of the curved part B: Base line in contact with the two curved parts opposing point A S: Chord with a length of 100 μm parallel to the base line B L: Distance between the chord S and the vertex A

Claims

1. An artificial leather comprising, as main constituent elements, fibers containing a polyester-based resin as a main component, wherein the fibers are long fibers, the average single fiber diameter of the fibers is 2.0 μm or more and 7.0 μm or less, the fibers are crimped fibers having a curvature of 5.0 to 20.0%, and the fibers are dispersed as single fibers.

2. The artificial leather according to claim 1, having pile on at least one surface, and the number of fiber ends observed from a 200 μm × 200 μm field of view of the surface having the pile being 4 or more.

3. The artificial leather according to claim 1 or 2, wherein a resin layer is provided on at least a part of at least one surface.

4. The X-ray diffraction intensity I of the (-105) plane measured with wide-angle X-rays, calculated by the following formula (1) （－１０５） and the X-ray diffraction intensity I of the (100) plane （１００） The artificial leather according to claim 1 or 2, wherein the diffraction intensity ratio Z is 0.002 or more and 0.015 or less. Z = I （－１０５） / I （１００） ...(1)

5. An interior material for a vehicle, comprising the artificial leather according to claim 1 or 2.

6. A seat, comprising the artificial leather according to claim 1 or 2.

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