Artificial leather, vehicle interior material, seat, and clothing

Abstract

To provide an artificial leather having sufficient contact cool feeling performance even without applying a functional material on a fiber surface.SOLUTION: An artificial leather includes a nonwoven fabric including, as a main component, fibers that are made of a polyester-based resin and have the average single fiber diameter of 2.0 μm or more and 7.0 μm or less, and an elastomer. The fibers are dispersed as single fibers. At least one surface of the artificial leather is either one of a surface having piloerection, a surface having a resin layer thereon, and a surface having piloerection and the resin layer thereon. The arithmetic average height Sa of the one surface is 10 μm or less. A ratio Z between X-ray diffraction strength I (-105) of a surface (-105) measured by a wide angle X ray calculated by the following formula 1 and X-ray diffraction strength I (-100) of a surface (100) measured by the wide angle X ray is 0.010 or less. Z=I (-105) / I (-100)...(formula 1)SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to artificial leather.

Background Art

[0002] Artificial leather has elegant appearance, good touch, good heat resistance, good dyeing fastness, etc., and is used in applications such as shoes, bags, clothing, furniture, sports goods, general industrial applications such as automobile interiors and seats, and even industrial products.

[0003] As such artificial leather, for example, in Patent Document 1, there is proposed a pile-finished artificial leather containing a fabric impregnated with a polymer elastomer and having a pile surface including specific pile, wherein the arithmetic mean height Sa and the peak density Spd of the pile surface are within a specific range. And according to this invention, it is described that a pile-finished artificial leather that is less likely to generate a heterogeneous and rough appearance quality with a dry touch making a rattling sound even when the pile surface is rubbed can be obtained.

[0004] Further, in Patent Document 2, in a nubuck-finished artificial leather including a scrim that is a woven or knitted fabric and a fiber layer that is a surface layer, a nubuck-finished artificial leather in which the arithmetic mean height Sa of the surface grain and the arithmetic mean height Sa of the back surface are within a specific range is proposed. And it is described that the nubuck-finished artificial leather of this invention has excellent surface quality.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In recent years, as the uses of artificial leather have been expanding even further, there have emerged applications that require contact cold feeling, such as not only feeling warmth when touched like conventional artificial leather, but also feeling coolness or obtaining a refreshing touch.

[0007] However, conventional artificial leather has not been assumed to have such an effect at all, and it has been difficult to directly use it for new applications. Therefore, when trying to impart contact cold feeling performance to conventional artificial leather, in order to increase the thermal conductivity of the fiber itself, for example, surface treatment such as fixing ceramic fine particles with high thermal conductivity to the fiber is carried out. However, when such surface treatment is performed, since it is merely that functional materials such as ceramic fine particles adhere to the fiber surface, etc., there is a risk that the contact cold feeling performance will decrease as time passes when used, etc.

[0008] Therefore, an object of the present invention is to provide an artificial leather having sufficient contact cold feeling performance without imparting a functional material to the fiber surface.

Means for Solving the Problems

[0009] As a result of intensive studies to achieve the above object, the present inventors have obtained the finding that in order to have contact cold feeling performance, first, the surface contact area when a person's skin touches artificial leather is important. For example, in artificial leather such as that disclosed in Patent Document 1, since ultrafine fiber generating type fibers are used, ultrafine fibers generated from the same ultrafine fiber generating type fibers tend to gather to form fiber bundles, and unevenness occurs on the surface of the artificial leather, resulting in a small contact area, so contact cold feeling performance cannot be obtained.

[0010] On the other hand, it was also found that the density of the fibers on the surface of artificial leather is also important for the contact cooling performance. For example, in the artificial leather disclosed in Patent Document 2, since ultrafine fibers are formed by a papermaking method, a uniform surface is obtained. Therefore, although the contact area on the surface of the artificial leather increases, due to the process of entangling ultrafine fibers by a water jet punch, the ultrafine fibers are oriented in the thickness direction of the artificial leather, and thus the surface may lack density. As a result, the area occupied by the fibers on the surface of the artificial leather becomes small, and heat cannot be sufficiently conducted from the human skin to the fibers, and thus the contact cooling performance cannot be obtained either.

[0011] Therefore, as a result of further intensive studies, the fibers are dispersed as single fibers, at least one surface is a surface having erected hairs and / or a surface provided with a resin layer, and further, the arithmetic mean height Sa of the surface is set to a specific value or less, and the ratio of the X-ray diffraction intensity measured by wide-angle X-rays is set within a specific range, whereby the contact cooling performance can be obtained, and further, it was found that the durability against friction and the weather resistance can be improved.

[0012] The present invention has been completed based on these findings, and according to the present invention, the following inventions are provided.

[0013] [1] An artificial leather comprising a non-woven fabric made of a polyester resin and containing fibers having an average single fiber diameter of 2.0 μm or more and 7.0 μm or less as main components, and a polymer elastomer, wherein the fibers are dispersed as single fibers, at least one surface of the artificial leather is any one of a surface having erected hairs, a surface provided with a resin layer, and a surface having erected hairs and provided with a resin layer, the arithmetic mean height Sa of the one surface is 10 μm or less, furthermore, the X-ray diffraction intensity I of the (-105) plane measured by wide-angle X-rays calculated by the following formula 1 (-105) and the ratio Z of the X-ray diffraction intensity I of the (100) plane measured by wide-angle X-rays (100) is 0.010 or less. An artificial leather.

[0014] Z = I (-105) / I (100) ···(Formula 1) [2] The artificial leather according to [1], wherein the fiber is a long fiber.

[0015] [3] The artificial leather according to [1] or [2], wherein the degree of cross-sectional irregularity of the fiber is 1.00 or more and 1.15 or less.

[0016] [4] The artificial leather according to any one of [1] to [3], wherein the content ratio of the polymer elastomer in the artificial leather is 5% by mass or more and 50% by mass or less.

[0017] [5] The apparent density is 0.25 g / cm 3 or more and 0.50 g / cm 3 or less. The artificial leather according to any one of [1] to [4].

[0018] [6] The artificial leather according to any one of [1] to [5], further comprising a woven or knitted fabric composed of fibers having an average single fiber diameter of 5.0 μm or more and 25.0 μm or less.

[0019] [7] A step of forming a web made of a polyester resin and containing fibers having an average single fiber diameter of 2.0 μm or more and 7.0 μm or less as main components; A step of thermally pressing the web at a temperature of 80°C or more and 230°C or less for a time of 5 seconds or more and 120 seconds or less to form a non-woven fabric; A step of applying a polymer elastomer to the non-woven fabric to form a polymer elastomer-applied sheet; Forming any one of a surface having pile, a surface provided with a resin layer, and a surface having pile and provided with a resin layer on at least one surface of the polymer elastomer-applied sheet, and setting the arithmetic mean height Sa of the one surface to 10 μm or less. Furthermore, 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 measured by wide-angle X-ray (100) The ratio Z of which is 0.010 or less. A method for manufacturing artificial leather.

[0020] Z = I (-105) / I (100) ···(Formula 1).

[0021] [8] The method for manufacturing artificial leather according to [7], wherein the web is formed by a spunbond method.

[0022] [9] An interior material for a vehicle, characterized by being made of the artificial leather according to any one of [1] to [6].

[0023]

[10] A seat, characterized by being made of the artificial leather according to any one of [1] to [6].

[0024]

[11] Clothing, characterized by being made of the artificial leather according to any one of [1] to [6]. [Advantages of the Invention]

[0025] According to the artificial leather of the present invention, it is possible to provide an artificial leather having excellent contact cool feeling performance without imparting a functional material to the fiber surface. And, due to the excellent characteristics of this artificial leather, it can be suitably used for a wide range of applications, particularly interior materials for vehicles, seats, and clothing. [Embodiments for Carrying out the Invention]

[0026] The artificial leather of the present invention is an artificial leather comprising a non-woven fabric made of a polyester-based resin and containing fibers having an average single fiber diameter of 2.0 μm or more and 7.0 μm or less as main components, and a polymer elastic body, wherein the fibers are dispersed as single fibers, and at least one surface of the artificial leather is any one of a surface having piloerection, a surface provided with a resin layer, and a surface having piloerection and provided with a resin layer, the arithmetic mean height Sa of the one surface is 10 μm or less, and further, 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 ratio Z of the X-ray diffraction intensity I of the (100) plane measured by wide-angle X-ray (100) is 0.010 or less Z = I(-105) / I (100) ···(Formula 1) The artificial leather of 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.

[0027] [Fiber] The nonwoven fabric of the artificial leather of the present invention is made of a polyester resin and contains fibers with an average single fiber diameter of 2.0 μm or more and 7.0 μm or less as main components. By doing so, it is possible to achieve both a graceful and high-class appearance and mechanical properties at a high level, and to obtain an artificial leather with excellent durability.

[0028] First, 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 in particular, polyethylene terephthalate is particularly preferably used.

[0029] In the present invention, the polyester resin refers not only to each polyester resin itself such as the above-mentioned polyethylene terephthalate, but also to a mixture, copolymer of the above-mentioned polyester resins, and those to which additives are added to these resins. As this additive, it is added and contained within a range that does not inhibit the object of the present invention according to various purposes, and specifically, inorganic particles such as titanium oxide particles, lubricants, pigments, heat stabilizers, ultraviolet absorbers, conductive agents, heat storage agents, antibacterial agents, etc. are mentioned.

[0030] And the fiber has an average single fiber diameter of 2.0 μm or more and 7.0 μm or less. Being within this range can obtain a soft and smooth touch, the form of the non-woven fabric is stable, and the handleability is good. Regarding the lower limit of the average single fiber diameter range, being 2.0 μm or more, preferably 2.5 μm or more, more preferably 3.0 μm or more can result in artificial leather with higher form stability. On the other hand, regarding the upper limit of the average single fiber diameter range, being 7.0 μm or less, preferably 6.0 μm or less, more preferably 5.0 μm or less can result in more flexible artificial leather.

[0031] In addition, in the artificial leather of the present invention, the average single fiber diameter (μm) refers to the one obtained as follows. (1) Cut out 5 test pieces of 2 cm × 2 cm from the artificial leather. (2) Photograph the cross-section of the test piece using a scanning electron microscope (for example, "VHX-D510 type" manufactured by KEYENCE CORPORATION, etc.). (3) Randomly select 20 circular or nearly circular elliptical fibers. (4) Measure the diameters of the 20 single fibers. (5) Perform (2) to (4) on all test pieces, and round off the arithmetic mean value (μm) of the obtained single fiber diameters to the second decimal place.

[0032] Furthermore, in the artificial leather of the present invention, the fiber is dispersed as a single fiber. Here, In the present invention, the fiber being "dispersed as a single fiber" means that there is substantially no fiber bundle on the surface where a large number of fibers gather together to form a thick fiber. Specifically, it is judged by observing and confirming with the method described later. In other words, even if the artificial leather slightly contains a structure entangled in the state of a fiber bundle due to manufacturing constraints or the like, it is not immediately considered that it is "not dispersed as a single fiber".

[0033] As described above, when the fibers constituting the artificial leather are in a state of being dispersed randomly, the entire artificial leather has a uniform structure, and a homogeneous surface without unevenness can be obtained. Therefore, when a person's skin touches it, the contact area is large, and it is easy to obtain an artificial leather with excellent contact cold feeling performance.

[0034] Generally, in an artificial leather using ultrafine fiber generating type fibers, due to the formation of a structure such as entanglement as the ultrafine fiber generating type fibers, in the ultrafine fiber generation process, a plurality of ultrafine fibers originally in the ultrafine fiber generating type fibers form a fiber bundle. When the structure is formed by such fiber bundles, since there is a tendency to form the entanglement part and the surface depending on the size of the fiber bundle, it is difficult to easily obtain a uniform structure as expected in the present invention, and the surface tends to become rough. Therefore, it can become an artificial leather with poor contact cold feeling performance.

[0035] In addition, the determination of whether the fibers are "dispersed as single fibers" is performed as follows. (1) Randomly select 10 areas of 1 cm × 1 cm from the surface of the artificial leather. (2) Observe this surface at 200 times magnification using a stereomicroscope (for example, "VHX-X1 type" manufactured by Keyence Corporation) or a scanning electron microscope (for example, "VHX-D510 type" manufactured by Keyence Corporation). (3) Count the fiber bundles in which 10 or more fibers gather and continue for a length of 1 mm or more. (4) In the 10 areas, count the number of fiber bundles in the same way. If the arithmetic mean value is 3 or less, it is determined that the fibers are "dispersed as single fibers".

[0036] Also, in the artificial leather of the present invention, it is preferable that the above-mentioned fibers are long fibers. By being long fibers, not only does the artificial leather become stronger, but also the fibers are less likely to pull out from the artificial leather, so the artificial leather has better wear resistance.

[0037] In the present invention, the term "long fiber" means a fiber that is not a short fiber intentionally cut after spinning, that is, a substantially continuous fiber with a fiber length of 100 mm or more. More specifically, for example, it means a fiber that is not a short fiber intentionally cut to have a fiber length of about 3 mm to 80 mm. However, in the process of manufacturing artificial leather, after a polyester resin is 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 forming pile on the surface of the sheet, etc., even if they are cut to a certain length, such fibers shall be regarded as long fibers.

[0038] And in the artificial leather of the present invention, it is preferable that the cross-sectional deformation degree of the fiber is 1.00 or more and 1.15 or less. When the cross-sectional deformation degree is 1.00 at the lower limit, the cross-section of the fiber is a perfect circle, and as the cross-sectional deformation degree increases, it is shown that the cross-section of the fiber is deformed in a direction different from the perfect circle. Regarding the upper limit of this cross-sectional deformation degree range, preferably it is 1.15 or less, more preferably 1.10 or less, and even more preferably 1.05 or less. As a result, anisotropy is suppressed when the fiber bends. Therefore, when pile is formed on the surface of the artificial leather, the pile formed on the surface of the artificial leather is likely to be aligned, and the artificial leather is full of a sense of luxury.

[0039] In the artificial leather of the present invention, the cross-sectional deformation degree is a value measured and calculated by the following procedure. (1) Cut out 5 test pieces of 2 cm × 2 cm. When cutting out test pieces from a product made of artificial leather, randomly collect them from a part excluding the seams and embossed parts of the product. (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 10 fibers, and in order to observe the exact shape of each fiber cross-section, adjust the image to the direction where there is no reflection or the minimum reflection of the fiber side surface of the corresponding fiber and then photograph the image. (4) For the cross-section of the selected fiber, divide the diameter (μm) of the minimum circumscribed circle of the cross-section by the diameter (μm) of the maximum inscribed circle of the cross-section to obtain the degree of fiber irregularity (unitless) of the fiber. (5) Perform (2) to (4) for all test pieces, and round off the arithmetic mean value (unitless) of the obtained degrees of irregularity to the third decimal place. Round off to the third decimal place.

[0040] Also, the fiber constituting the artificial leather of the present invention may be a crimped fiber. By using a crimped fiber, a more flexible artificial leather can be obtained. As the crimped fiber, side-by-side type fibers or eccentric core-sheath type fibers can be used.

[0041] [Nonwoven fabric] The artificial leather of the present invention includes a nonwoven fabric containing the above-mentioned fiber as a main component. Here, in the present invention, "containing the fiber as a main component" means that in the part of the artificial leather excluding the layer made of reinforcing fibers described later and the polymer elastomer such as polyurethane, the mass ratio of the fiber is 50% by mass or more.

[0042] The nonwoven fabric according to the present invention may be a long fiber nonwoven fabric such as a spunbond nonwoven fabric or a meltblown nonwoven fabric, or a short fiber nonwoven fabric such as a needle-punched nonwoven fabric or a paper-making nonwoven fabric, as long as the conditions of the arithmetic mean height Sa or the ratio Z of the X-ray diffraction intensity on one surface of the artificial leather described later are satisfied. Among them, as described above, it is preferable that the fiber is a long fiber, that is, it is preferable that it is a long fiber nonwoven fabric, and further, since high strength and good abrasion resistance can be obtained, it is more preferable that it is a spunbond nonwoven fabric.

[0043] [Polymer elastomer] The artificial leather of the present invention further includes a polymer elastomer. By being such an artificial leather, the texture and physical properties of the artificial leather become good.

[0044] As this polymer elastomer, a polyurethane obtained by the reaction of a polymer diol, an organic diisocyanate, and a chain extender, or a polyester elastomer obtained by copolymerizing various aliphatic polyols with polybutylene terephthalate is preferably used.

[0045] Here, more preferable embodiments of the above polyurethane will be described respectively.

[0046] (1) Polyurethane As the above polyurethane, either an organic solvent-based polyurethane resin used in a state dissolved in an organic solvent or an aqueous dispersion-type polyurethane resin used in a state dispersed in water can be adopted. Here, in the present invention, the aqueous dispersion-type polyurethane resin refers to a polyurethane resin having a hydrophilic group and a solubility in DMF of less than 40 g / 100 g-DMF (the polyurethane dissolves no more than 40 g in 100 g of DMF). Conversely, a polyurethane resin having a solubility in DMF of 40 g / 100 g-DMF or more (the polyurethane can dissolve 40 g or more in 100 g of DMF) is an organic solvent-based polyurethane resin.

[0047] (2) Polymer diol As the polymer diol used in the above polyurethane, at least one polymer diol selected from polymer diols such as polyester diol, polyether diol, polycarbonate diol, or polyester polyether diol having an average molecular weight of 500 or more and 3000 or less can be used, but it is preferable to contain a polyether diol or a polycarbonate diol that is less likely to impair the function as a binder against repeated washing and has excellent hydrolysis resistance.

[0048] (3) Organic diisocyanate Examples of the organic diisocyanate used in the above polyurethane include aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and xylylene diisocyanate, and aromatic diisocyanates such as diphenylmethane diisocyanate and tolylene diisocyanate. These can also be used in combination.

[0049] (4) Chain extender As the chain extender used in the above polyurethane, preferably amine-based chain extenders such as ethylenediamine and methylenebis(aniline), and diol-based chain extenders such as ethylene glycol can be used. Also, a polyamine obtained by reacting a polyisocyanate with water can be used as a chain extender.

[0050] (5) Other additives In addition, the above polyurethane can contain various additives according to the purpose, such as 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-resistant stabilizers such as polycarbodiimide, plasticizers, antistatic agents, surfactants, coagulation regulators, and dyes. This is the same for other polymer elastomers in terms of these additives.

[0051] In the present invention, the content ratio of the polymer elastomer in the artificial leather can be appropriately adjusted in consideration of the type of the polymer elastomer used, the manufacturing method of the polymer elastomer, 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 polymer elastomer in the artificial leather is preferably 5% by mass or more and 50% by mass or less. When the lower limit of the content ratio range of polyurethane is 5% by mass or more, more preferably 10% by mass or more, the abrasion resistance of the artificial leather can be improved. On the other hand, when the upper limit of the content ratio range of the polyurethane is 50% by mass or less, more preferably 45% by mass or less, and still more preferably 40% by mass or less, the artificial leather can be made more flexible.

[0052] In the present invention, the content ratio of the polymer elastomer in the artificial leather refers to the value measured and calculated by the following method. (1) Cut out five test pieces of 2 cm × 2 cm and measure the mass of the test pieces. When cutting out the 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 adjust them to a standard state of a temperature of 20 ± 2°C and a relative humidity of 65 ± 4% before use. (2) Immerse the test pieces in a solvent that elutes fibers and reinforcing fibers, or a solvent that elutes the polymer elastomer, and calculate the content (g) of the polymer elastomer from the mass change before and after elution. For example, in the case of artificial leather containing an 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 the polyurethane. (3) Divide the content of the polyurethane obtained in (2) by the mass (g) of the test piece obtained in (1) to calculate the content ratio (% by mass) of the polyurethane. (4) Perform (2) to (3) on all the test pieces, calculate the arithmetic mean value (% by mass) of the obtained content ratios (% by mass) of the polyurethane, and round it to the first decimal place.

[0053] [Artificial Leather] The artificial leather of the present invention includes the above-mentioned non-woven fabric and the above-mentioned polymer elastomer. And at least one surface of this artificial leather is any one of a surface having pile, a surface provided with a resin layer, and a surface having pile and provided with a resin layer.

[0054] Note that whether it is a surface having pile or not shall be determined by performing the following observations on the surface. (1) With the pile surface of the artificial leather reversed using a lint brush or the like, a thin section with a thickness of 1 mm is prepared in the cross-sectional direction of a plane perpendicular to the longitudinal direction of the artificial leather from a randomly selected position in the artificial leather so that a cross-section in the thickness direction can be seen. (2) Among the cross-sections of the artificial leather with a scanning electron microscope (for example, "VHX-D510 type" manufactured by Keyence Corporation), the cross-section is observed at 500 times magnification at a position in the observation field that does not contain the resin of the resin layer described later. (3) In the cross-section, a layer composed only of fibers oriented in the thickness direction is defined as the pile part, and the length from the intersection of the fibers oriented in the thickness direction and the fibers oriented in the plane direction of the artificial leather to the tip of the pile is measured as the pile length (μm). (4) In the region with a width of 3000 μm in the photographed SEM image, if piles with a length of 50 μm or more are confirmed from the fiber complex substrate and 10 or more can be confirmed, it is considered to "have piles".

[0055] When this one surface is a surface having piles, it is more preferable that the number of fiber ends observed from a 200-μm square field of view of this surface having piles is 4 or more. The larger the number of fiber ends present on the surface, the larger the number of piles. By setting the number of fiber ends observed from a 200-μm square field of view of the piles to preferably 4 or more, more preferably 7 or more, and even more preferably 10 or more, it can be used as artificial leather with a beautiful suede-like or nubuck-like appearance.

[0056] Note that in the present invention, the number of fiber ends observed from a 200-μm square field of view is determined by the following measurement. (1) Cut out 5 test pieces of 2 cm × 2 cm. (2) Use a lint brush or the like to reverse the nap surface of the test piece, and photograph three locations 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.

[0057] Next, whether it is the surface provided with the resin layer shall be determined by performing the following observations on the surface. (1) From a position randomly selected in the artificial leather, prepare a thin section with a thickness of 1 mm in the cross-sectional direction of a plane perpendicular to the longitudinal direction of the artificial leather so that the cross-section in the thickness direction can be seen. (2) Observe the cross-section of the thin section at a magnification of 500 times using a scanning electron microscope (for example, "VHX-D510 type" manufactured by Keyence Corporation). (3) Among the cross-sections, a film-like polymer elastomer having a thickness of 10 to 500 μm and present on at least one outermost surface of the artificial leather (thin section) is defined as the resin layer. (4) In the region with a width of 3000 μm in the photographed SEM image, the surface where a resin layer with a total width of 1000 μm or more can be confirmed in the width direction is defined as the "surface provided with the resin layer".

[0058] Here, the resin layer according to the present invention is a layer made of a polymer elastomer such as polyurethane, and it may be the same resin as the polymer elastomer contained in the artificial leather or a different resin.

[0059] When using polyurethane as the polymer elastomer of the resin layer, for example, polyether-based polyurethane, polyester-based polyurethane, polycarbonate-based polyurethane, acrylic-based polyurethane, etc. can be mentioned, and they can be used alone or in combination of two or more. And these polyurethanes can be any of solventless (solvent-free), hot melt, solvent-based or water-based, and can be either one-component or two-component curing type.

[0060] And the thickness of the resin layer according to the present invention is not particularly limited, but when it is 30 μm or more and 200 μm or less, it is likely to achieve both the texture and wear resistance of 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.

[0061] In the present invention, the thickness of the resin layer is calculated by taking 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 to the first decimal place.

[0062] In addition, in the artificial leather according to the present invention, the "surface having pile and provided with a resin layer" specifically refers to, for example, a so-called semi-silver artificial leather, that is, an artificial leather in which a resin layer is discretely provided on the surface having pile. Here, "discretely provided with a resin layer" means a form in which the resin layer is arranged in a lattice shape, zigzag shape, twill weave shape, crepe weave shape, random shape, etc. in the following shapes. Also, as the shape of the resin layer, various shapes such as circular, star-shaped, heart-shaped, and polygons such as triangle, square, hexagon, and 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.

[0063] Next, for the artificial leather of the present invention, the arithmetic mean height Sa of the one surface is 10 μm or less. Here, when both surfaces are the surfaces having the above-mentioned raised hairs, the surfaces provided with the resin layer, or the surfaces having the raised hairs and provided with the resin layer, it is only necessary that at least one surface satisfies this requirement. When the arithmetic mean height Sa of this one surface is 10 μm or less, preferably 8 μm or less, more preferably 6 μm or less, the area of the surface of the artificial leather in contact with human skin becomes larger, and the artificial leather with excellent contact cold feeling performance is obtained.

[0064] Note that the arithmetic mean height Sa of the one surface is a value measured and calculated by the following procedure. (1) Cut out three test pieces of 4.0 cm × 4.0 cm. (2) Using a non-contact surface roughness and shape measuring machine (for example, "One Shot 3D Measurement Macroscope VR-3200" manufactured by Keyence Corporation, etc.), a 18 mm × 24 mm range of the surface having raised hairs of the test piece, the surface provided with the resin layer, or the surface having raised hairs and provided with the resin layer is subjected to fringe projection image shooting at a magnification of 12 times with structured illumination light. (3) Perform surface shape correction to remove undulations. (4) Calculate the arithmetic mean height Sa (μm). (5) Perform (2) to (4) for all the test pieces, and round off the arithmetic mean value (μm) of the obtained arithmetic mean height Sa to the third decimal place.

[0065] Also, the arithmetic mean height Sa of the one surface can be controlled by adjusting the temperature and time of the hot press described later.

[0066] Furthermore, for 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 ratio Z of the X-ray diffraction intensity I of the (100) plane measured by wide-angle X-ray (100) is 0.010 or less Z = I (-105) / I (100) ···(Formula 1) Here, the X-ray diffraction intensity I of the (-105) plane measured by wide-angle X-rays (-105) means the degree of fiber orientation in the thickness direction, and the X-ray diffraction intensity I of the (100) plane measured by wide-angle X-rays (100) means the degree of fiber orientation in the plane direction.

[0067] Regarding the lower limit of the range of the ratio Z, preferably it is 0.002 or more, more preferably 0.004 or more, and even more preferably 0.005 or more, so that artificial leather with high morphological stability is obtained, and the process passing property is also high. On the other hand, regarding the upper limit of the range of the ratio Z, by being 0.010 or less, it is easy to make the surface dense, and the contact area with human skin can be increased.

[0068] In the artificial leather of the present invention, the ratio Z of the X-ray diffraction intensity I of the (-105) plane measured by wide-angle X-rays (-105) and the X-ray diffraction intensity I of the (100) plane measured by wide-angle X-rays (100) is the value measured and calculated by the following measurement. (1) Cut out a test piece of 1.5 cm × 1.5 cm and place it on a Si non-reflecting plate. (2) Using an X-ray diffractometer (for example, "D8 ADVANCE" manufactured by Bruker Japan Co., Ltd., etc.), with the X-ray source as CuKα ray, output 40 kV, 40 mA, and perform a 2θ-θ continuous scan (2θ = 5° to 60°, step width 0.01711°, scan speed 0.5 seconds / step) with the slit system DS = 0.3°. (3) The X-ray diffraction intensity I of the (-105) plane measured by wide-angle X-rays obtained from the diffraction peak (-105) (unitless), the X-ray diffraction intensity I of the (100) plane measured by wide-angle X-rays (100) (unitless), from the following formula 1, calculate the ratio Z (unitless) and round it to the fifth decimal place Z = I (-105) / I (100) ···(Formula 1).

[0069] Note that the ratio Z can be controlled by adjusting the water pressure of the water entanglement, the temperature and pressure of the hot press, etc., which will be described later.

[0070] The artificial leather of the present invention preferably has an apparent density of 0.25 g / cm 3 or more and 0.50 g / cm 3 or less. Regarding the lower limit of the apparent density, it is preferably 0.25 g / cm 3 or more, more preferably 0.30 g / cm 3 or more, and even more preferably 0.35 g / cm 3 or more. By doing so, the surface becomes denser, and an artificial leather excellent in contact cold feeling performance can be obtained. On the other hand, regarding the upper limit of the apparent density, it is preferably 0.50 g / cm 3 or less, so that the artificial leather is flexible and has a good texture.

[0071] In the present invention, the apparent density of the artificial leather means that for the artificial leather, the thickness obtained by the "6.1.1 Method A" of "6.1 Thickness (ISO method)" in JIS L1913:2010 "General Test Methods for Nonwoven Fabrics" is taken as the thickness of the artificial leather (μm), and the mass per unit area obtained by the "6.2 Mass per Unit Area (ISO method)" of the same standard is taken as the basis weight of the artificial leather (g / m 2 ), and the value (g / cm 3 ) obtained by rounding the value obtained from these by the following formula to the third decimal place is the value in question (Value (g / cm 3 )) = (Basis weight of artificial leather (g / m 2 )) / (Thickness of artificial leather (μm)) ··· (Formula).

[0072] In order to obtain higher physical properties, the artificial leather of the present invention preferably further includes a woven or knitted fabric composed of fibers having an average single fiber diameter of 5.0 μm or more and 25.0 μm or less. The "woven or knitted fabric" mentioned here is a general term for woven fabrics and knitted fabrics.

[0073] Regarding the fibers of this knitted or woven fabric, for the upper limit of the range of the average single fiber diameter, preferably it is 25.0 μm or less, more preferably 15.0 μm or less, and still more preferably 13.0 μm or less, whereby an artificial leather excellent in flexibility is obtained. On the other hand, for the lower limit of the range of the average single fiber diameter, preferably it is 5.0 μm or more, more preferably 7.0 μm or more, and still more preferably 10.0 μm or more, whereby an artificial leather with good morphological stability is obtained.

[0074] In the present invention, the average single fiber diameter of the fibers of the knitted or woven fabric is obtained by taking a scanning electron microscope (SEM) photograph of the cross-section of the artificial leather, randomly selecting 10 fibers constituting the knitted or woven fabric, measuring the single fiber diameter of the fibers, calculating the arithmetic mean value (μm) of the 10 fibers, and rounding off to the second decimal place. However, when fibers with a non-circular cross-section are employed, first, the cross-sectional area (μm 2 ) of the fiber is measured, and the diameter of the fiber (μm), that is, the equivalent circular diameter, is obtained by calculating the diameter when the cross-section is regarded as circular. Further, when the fiber is a multifilament as described below, the diameter of the single fiber constituting the multifilament is taken as the average single fiber diameter of the fiber.

[0075] Examples of this knitted or woven fabric include woven fabrics. As the basic weave of this woven fabric, twill or satin may be used, but a plain weave that is less likely to cause misalignment is preferably used.

[0076] As the type of fiber constituting the woven fabric, it is preferable to use filament yarn, spun yarn, a mixed composite yarn of filament yarn and spun yarn, etc., and from the viewpoint of durability, particularly mechanical strength, etc., it is more preferable to use a multifilament made of a polyester-based resin or a polyamide-based resin.

[0077] Furthermore, when the fibers constituting the fabric are multifilaments, the twist number of the multifilaments is preferably 1000 T / m to 4000 T / m. When the upper limit of the twist number range is preferably 4000 T / m or less, more preferably 3500 T / m or less, and even more preferably 3000 T / m or less, artificial leather with excellent flexibility can be obtained. On the other hand, when the lower limit of the twist number range is preferably 1000 T / m or more, more preferably 1500 T / m or more, and even more preferably 2000 T / m or more, when the non-woven fabric and the fabric are intertwined and integrated by needle punching or the like, damage to the fibers constituting the fabric can be prevented, and artificial leather with excellent mechanical strength can be obtained.

[0078] In addition, examples of the woven or knitted fabric include knitted fabrics. The basic weave of this knitted fabric can be either a plain weave or a warp weave. Examples of the plain weave include a flat weave, a rubber weave, and a pearl weave, and examples of the warp weave include a denim weave, a cord weave, and an atlas weave.

[0079] As for the type of fibers constituting the knitted fabric, it is also preferable to use filament yarns, spun yarns, mixed composite yarns of filament yarns and spun yarns, etc. From the viewpoints of durability, particularly mechanical strength, etc., it is more preferable to use multifilaments made of polyester-based resins or polyamide-based resins.

[0080] Furthermore, when the fibers constituting the knitted fabric are multifilaments, the twist number of the multifilaments is preferably 1000 T / m to 4000 T / m. When the upper limit of the twist number range is preferably 4000 T / m or less, more preferably 3500 T / m or less, and even more preferably 3000 T / m or less, artificial leather with excellent flexibility can be obtained. On the other hand, when the lower limit of the twist number range is preferably 1000 T / m or more, more preferably 1500 T / m or more, and even more preferably 2000 T / m or more, when the non-woven fabric and the knitted fabric are intertwined and integrated by needle punching or the like, damage to the fibers constituting the knitted fabric can be prevented, and artificial leather with excellent mechanical strength can be obtained.

[0081] [Method for manufacturing artificial leather] The artificial leather of the present invention is manufactured by the following manufacturing method. That is, the manufacturing method of this artificial leather is forming a web made of a polyester resin and containing fibers having an average single fiber diameter of 2.0 μm or more and 7.0 μm or less as main components; thermally pressing the web at a temperature of 80°C or higher and 230°C or lower for 5 seconds or more and 120 seconds or less to form a non-woven fabric; applying a polymer elastomer to the non-woven fabric to form a polymer elastomer-applied sheet; forming any one of a surface having raised hairs, a surface provided with a resin layer, and a surface having raised hairs and provided with a resin layer on at least one surface of the polymer elastomer-applied sheet, and setting the arithmetic mean height Sa of the one surface to 10 μm or less; Furthermore, the X-ray diffraction intensity I of the (-105) plane measured by wide-angle X-rays calculated by the following formula 1 (-105) and the X-ray diffraction intensity I of the (100) plane measured by wide-angle X-rays (100) and the ratio Z thereof is 0.010 or less Z = I (-105) / I (100) ···(Formula 1) The details of each step will be described below. 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.

[0082] (1) Step of forming a web First, in this step, a web made of a polyester resin and containing fibers having an average single fiber diameter of 2.0 μm or more and 7.0 μm or less as main components is formed.

[0083] As a method for forming this web, it is preferably formed by the spunbond method. Specifically, after melting the polyester-based resin and discharging it from the discharge holes of the die at a single-hole discharge rate of 0.05 g / min or more and 0.30 g / min or less, a gas at -15°C or higher and 50°C or lower is blown onto the polyester-based resin so as to include at least a part of the region within 200 mm from the discharge holes to form filaments. At least at the inlet, the filaments are drawn with a gas at -15°C or higher and 50°C or lower so that the spinning speed is 3000 m / min or more and 7000 m / min or less, and it is more preferable to obtain a web composed of fibers having an average single fiber diameter of 2.0 μm or more and 7.0 μm or less. Here, in the present invention, the "inlet" is the place where the wind speed of the gas for drawing is the highest between the discharge holes 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 holes becomes filaments is the smallest between the discharge holes and obtaining the web.

[0084] In this specific example, it is preferable to discharge the melted polyester-based resin from the discharge holes of the die at a single-hole discharge rate of 0.05 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 polyester-based 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 it is 0.05 g / min or more, more preferably 0.07 g / min or more, and still more preferably 0.09 g / min or more, so that 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 it is 0.30 g / min or less, more preferably 0.25 g / min or less, and still more preferably 0.20 g / min or less, so that artificial leather with an elegant appearance can be obtained within the range of the spinning speed described later, and fibers having an average single fiber diameter of 7.0 μm or less can be easily obtained.

[0085] 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 pore diameter range, preferably it is 0.05 mm or more, more preferably 0.07 mm or more, and still more preferably 0.09 mm or more, so that 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 pore diameter range, preferably it is 0.30 mm or less, more preferably 0.25 mm or less, and still more preferably 0.20 mm or less, so that 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 circular diameter) with the same hole area is referred to as the pore diameter.

[0086] And in the above specific example, after discharging the molten polyester-based resin from the discharge hole of the die, it is preferable to form a yarn by spraying 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 destabilize spinning by affecting the temperature of the discharge hole, it is avoided to spray 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 spraying the gas at a position close to the discharge hole.

[0087] 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 still 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 still more preferably 30°C or lower, so that the discharged polyester-based resin can be sufficiently cooled.

[0088] Note that the region where the gas is blown is preferably set to include at least a part of the region within 200 mm from the discharge hole, more preferably to include at least a part of the region within 150 mm from the discharge hole, and even more preferably 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 is usually difficult, and artificial leather with an elegant appearance can be obtained.

[0089] In addition, as the gas supply means used for blowing the gas, there is a method of supplying the gas from one or multiple directions of the polyester resin through a slit nozzle or a flow rectifying unit to a blower.

[0090] And in the above specific example, it is preferable that the distance between the discharge hole and the inlet is 100 mm or more and 3000 mm or less. Regarding the lower limit of the distance range between the discharge hole and the inlet, by setting it preferably to 100 mm or more, more preferably to 200 mm or more, and even more preferably to 300 mm or more, the fibrillation of the molten polyester 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, by setting it preferably to 3000 mm or less, more preferably to 2000 mm or less, and even more preferably to 1000 mm or less, the yarns made of the polyester resin discharged from the plurality of discharge holes can be stably guided to the inlet.

[0091] Furthermore, in the above specific examples, it is preferable that the yarn is set such that the spinning speed Vs (m / min) is 3000 m / min or more and 7000 m / min or less, at least at the inlet. Regarding the lower limit of the range of the spinning speed Vs (m / min), preferably 3000 m / min or more, more preferably 3500 m / min or more, and even more preferably 4000 m / min or more, sufficient molecular orientation can be achieved to obtain a moderately firm touch, and an artificial leather excellent in mechanical 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 7000 m / min or less, more preferably 6500 m / min or less, and even more preferably 6000 m / min or less, the yarn onto which the gas is sprayed can be drawn more stably.

[0092] In the present invention, the spinning speed Vs (m / min) at the inlet refers to the value 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 photographs at 500 - 1000 times magnification are taken with a microscope, and the widths of 10 fibers each are measured from each sample, for 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 10000 m in length is calculated as the single fiber fineness (dtex), rounding off the second decimal place. (3) Based on the following formula, the spinning speed is calculated from the single fiber fineness (dtex) in (2) and the single hole discharge amount (g / min) set under each condition, and rounded off to the first decimal place. Spinning speed (m / min) = (10000 × single hole discharge amount (g / min)) / single fiber fineness (dtex) ··· (formula).

[0093] In addition, regarding the lower limit of the temperature range of the gas used when pulling the yarn, it is preferably -15°C or higher, more preferably -10°C or higher, and even more preferably -5°C or higher, so that the above-mentioned yarn can be cooled uniformly. On the other hand, regarding the upper limit of the temperature range of the gas, it is preferably 50°C or lower, more preferably 40°C or lower, and even more preferably 30°C or lower, so that the above-mentioned yarn can be sufficiently cooled.

[0094] Furthermore, in the method for manufacturing artificial leather of the present invention, the ratio Vq / Vs of the gas flow rate Vq (m / min) to the spinning speed Vs (m / min) when spraying the above-mentioned 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, it is preferably 3×10 -3 or more, more preferably 4×10 -3 or more, and even more preferably 5×10 -3 or more, so that the above-mentioned yarn can be sufficiently cooled. 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 pulled more stably.

[0095] In addition, when the artificial leather is provided with a woven or knitted fabric, in this step, it is also preferable to further laminate and integrate the woven or knitted fabric on the web obtained by the above-mentioned method to provide the woven or knitted fabric. This woven or knitted fabric is basically the same as the above-mentioned woven or knitted fabric, but in this step, a woven or knitted fabric containing ultrafine fiber-expressing fibers as the main components can also be used in the same manner as the fibers of the above-mentioned web. In addition, as the means for integration, the thermal press described later can be mentioned.

[0096] (2) Step of forming a non-woven fabric (step of thermal pressing) Next, in this step, the web obtained by the above method is hot-pressed at a temperature of 80°C or higher and 230°C or lower for a time of 5 seconds or longer and 120 seconds or shorter to form a non-woven fabric. In the present invention, "hot-pressing" means dry hot-pressing and / or wet hot-pressing. And the above-mentioned dry hot-pressing specifically means pressing with a flat plate or roll heated to a temperature described later, and the above-mentioned wet hot-pressing specifically means using a flat plate or roll heated to a temperature described later and pressing the web in a state where it contains water so as to have a wet pickup rate described later. In addition, when hot-pressing with a heated roll, the degree of hot-pressing can be adjusted by adjusting the material of the roll, the pressure (linear pressure), or the clearance between the rolls. Among them, fixing the clearance of the roll to a certain width is more preferable because it is easy to adjust the thickness of the heat treatment sheet base material and, thus, the thickness of the artificial leather.

[0097] Regarding each condition of hot-pressing, first, the temperature during hot-pressing is 80°C or higher and 230°C or lower. The "temperature during hot-pressing" mentioned here refers to the surface temperature of the heated flat plate or roll. Regarding this temperature during hot-pressing, by setting the lower limit to 80°C or higher, preferably 120°C or higher, the fibers can be sufficiently fused to form a web with good morphological stability and processability, and furthermore, an artificial leather having a sufficiently smooth surface can be obtained. On the other hand, regarding the temperature during hot-pressing, by setting the upper limit to 230°C or lower, preferably 200°C or lower, it is possible to avoid excessive fusion of the fibers and obtain an artificial leather with a soft texture.

[0098] Next, the hot pressing time is 5 seconds or more and 120 seconds or less. Here, the "hot pressing time" when using a roll for hot pressing refers to the time during which at least one surface of the web is in contact with the roll. Regarding this hot pressing time, by setting the lower limit to 5 seconds or more, preferably 10 seconds or more, the fibers can be sufficiently fused to form a web with good morphological stability and processability, and furthermore, artificial leather with a sufficiently smooth surface can be obtained. On the other hand, regarding the hot pressing time, by setting the upper limit to 120 seconds or less, preferably 60 seconds or less, it is possible to avoid excessive fusion of the fibers and obtain artificial leather with a soft texture.

[0099] Also, when performing wet heat pressing, the wet pickup rate of the web before hot pressing is preferably 100% or more and 350% or less. The "wet pickup rate of the web" mentioned here is a value (%) obtained by rounding to the first decimal place the value obtained by the following formula from the mass (g) of the web before water absorption and the mass (g) of the web after water absorption (Value (%)) = (Mass of the web after water absorption (g) - Mass of the web before water absorption (g)) / (Mass of the web before water absorption (g)) × 100 ··· (Formula).

[0100] Regarding this wet pickup rate, by setting the lower limit to preferably 100% or more, more preferably 150% or more, heat can be evenly transmitted, and artificial leather with a smooth and uniform texture can be obtained. On the other hand, regarding the wet pickup rate, by setting the upper limit to preferably 350% or less, more preferably 300% or less, sufficient heat can be applied to the fibers, the fibers can be sufficiently fused, a web with good morphological stability and processability can be formed, and furthermore, artificial leather with a sufficiently smooth surface can be obtained.

[0101] (3) Step of forming a polymer elastomer-imparting sheet Then, in this step, a polymer elastomer is applied to the nonwoven fabric obtained by the above method to form a polymer elastomer-applied sheet. The "polymer elastomer" mentioned here is the same as the polymer elastomer described above.

[0102] As a method for applying the polymer elastomer, when the polymer elastomer is polyurethane, a method of dissolving polyurethane or its precursor in a solvent such as N,N'-dimethylformamide or dimethyl sulfoxide (solvent method), or a method using an aqueous dispersion type polyurethane liquid in which a mixture containing at least a polymer diol, an organic diisocyanate, and a chain extender is dispersed as an emulsion in water (aqueous dispersion method) is preferably used. In the case of the former solvent method, for example, a method of substantially coagulating and solidifying the polyurethane precursor by immersing the web or the like in the polyurethane solution and then drying, or a method of coagulating by immersing the web or the like in the polyurethane solution and then immersing it in another solvent in which polyurethane is insoluble can be adopted. On the other hand, in the case of the latter aqueous dispersion method, for example, it can be coagulated by a dry coagulation method or the like in which the web or the like is immersed in the aqueous dispersion type polyurethane liquid and then dried. For drying, it is preferable to heat at a temperature such that the performance of the obtained polymer elastomer-applied sheet is not impaired, specifically, at 50°C or higher and 200°C or lower.

[0103] (4) Step of forming a surface having raised hairs Furthermore, in this step, on at least one surface of the polymer elastomer-applied sheet obtained by the above method, any one of a surface having raised hairs, a surface provided with a resin layer, and a surface having raised hairs and provided with a resin layer is formed, and the arithmetic mean height Sa of the one surface is 10 μm or less.

[0104] First, when forming a surface having raised hairs, preferably, a raising treatment can be performed on at least one surface of the polymer elastomer-imparted sheet obtained by the above method using sandpaper, a roll sander, or the like. Among them, by using sandpaper, uniform and dense raised hairs can be formed. In particular, in order to form uniform raised hairs on the surface of the polymer elastomer-imparted sheet, 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 multi-stage buffing with 3 or more buffing stages is performed, and the grit number of the sandpaper used in each stage is in the range of 120 (P120) to 600 (P600) defined in JIS R6010:2000 "Grain Size of Abrasives for Polishing Cloth Paper".

[0105] Also, when forming a surface provided with a resin layer, a one-component polyurethane resin colored with a pigment is coated on a mold-pressed release paper and dried in an oven. Next, a two-component polyurethane resin is coated as an adhesive and dried again in an oven, and the resin layer is bonded to the heat treatment sheet substrate or the like. After the reaction is completed, the release paper is peeled off, or a method such as directly coating 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, immersing it in another solvent in which polyurethane is insoluble and solidifying it, then performing water washing and drying, and then bonding it to the resin layer formed on the above release paper can be adopted.

[0106] In addition, when forming a surface having raised hairs and provided with a resin layer, a method of first performing the above raising treatment and then further forming a resin layer on the surface can be mentioned.

[0107] (5) Other processes By the above method, artificial leather with the ratio Z of 0.010 or less can be obtained. It is also preferable to further perform post-processing on this artificial leather. Needless to say, the artificial leather subjected to post-processing is also the artificial leather of the present invention.

[0108] First, in the process of performing this 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.

[0109] For example, the web or the like can also be dyed. As a specific means of dyeing, since the web or the like can be softened by adding a rubbing effect while being dyed, a flow-through dyeing machine is preferably used. The temperature of the dyeing solution when dyeing is preferably a temperature of 100°C or higher and 150°C or lower. Acid dyes, metal-containing dyes, reactive dyes, etc. are preferably used as the dyes. Also, reduction washing can be performed after dyeing.

[0110] Also, for the purpose of improving the uniformity of dyeing, it is also preferable to use a dyeing assistant when 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 performed after dyeing or in the same bath as dyeing.

[0111] Alternatively, various perforation processes (perforation processing), embossing processes, stitching processes, foil processes, resin printing processes, inkjet printing processes, laser etching processes, laminating processes, etc. can also be performed together as one of the post-processing.

[0112] [Interior materials for vehicles, seats, clothing] Since the artificial leather of the present invention has high strength and excellent form stability, it is preferably used for all applications including clothing applications, miscellaneous goods applications, shoe and bag applications, interior materials for vehicles, seats, CD curtains, DVD curtains, base materials for polishing pads, various polishing cloths, and wiping cloths, etc.

[0113] Among them, the vehicle interior material made of the above artificial leather is preferable because it can take advantage of the characteristic of excellent contact cold feeling. Examples of such vehicle interior materials include 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, an interior ceiling, a sun visor, an assist grip, etc. of an automobile being the above artificial leather is more preferable. In the present invention, the "vehicle" includes automobiles, airplanes, railway vehicles, ships, as well as vehicles such as carriages, palanquins, rickshaws, and further includes some industrial machines, construction machines, and agricultural machines that can move with people or animals on board.

[0114] Alternatively, the seat made of the above artificial leather is also similarly preferable because it can take advantage of the characteristic of particularly excellent contact cold feeling performance. Examples of such seats include at least a part of the skin material of a headrest, a seat surface, an armrest, a footrest, etc., for example, the part that directly contacts the seated person being the above artificial leather is more preferable. Of course, the seat of the present invention can be a seat for vehicles such as automobiles, airplanes, railway vehicles, ships, as well as seats for home, office, and store use. Note that the "seat" referred to in the present invention also includes chairs, benches, sofas, couches, stools, and seats.

[0115] In addition, clothing made from the artificial leather described above is also preferable because it can take advantage of the characteristic of excellent contact cold feeling performance. Examples of such clothing include tops such as T-shirts, polo shirts, dress shirts, blouses, cashmere, cut-sweaters, sweaters, vests, parkas, sweatshirts, turtlenecks, cardigans, tank tops, tube tops, etc.; outerwear such as coats, blazers, jackets, windbreakers, cloaks, capes, aprons, mantles, etc.; trousers such as slacks, jeans, shorts, etc.; skirts; dresses such as cocktail dresses, one-piece dresses, gowns, etc.; ceremonial costumes; suits; uniforms; underwear; upper parts and trims of shoes; hats; accessories such as bags, belts, scarves, neckties, wallets, etc., or clothing materials and accessories such as buttons, linings, pockets, etc., and can be suitably used for the lining of the above clothing items.

Examples

[0116] Next, the present invention will be specifically described based on examples. However, the present invention is not limited to these examples only. In the measurement of each physical property, those without special description were measured based on the above methods. Also, for (6) to (11) and (13) among the measurement methods, they were performed on the surface with erected hairs formed in the step of "forming a surface such as a surface with erected hairs" or the surface provided with a resin layer.

[0117] [Measurement method] (1) Average single fiber diameter (μm) of fibers of non-woven fabric, average single fiber diameter (μm) of fibers of woven or knitted fabric These average single fiber diameters (μm) were measured and calculated by the above method using "VHX-D510 type" manufactured by Keyence Corporation as a scanning electron microscope.

[0118] (2) Degree of cross-sectional irregularity of fibers (unitless) The degree of cross-sectional irregularity of the fibers contained as the main components in the artificial leather was measured and calculated by the above method using "VHX-D510 type" manufactured by Keyence Corporation as a scanning electron microscope.

[0119] (3)Dispersion state of fibers in artificial leather (dispersed as single fibers or in bundles) In artificial leather, the evaluation of whether the fibers are dispersed as single fibers was carried out using the "VHX-D510 type" manufactured by Keyence Corporation as a scanning electron microscope and evaluated by the above method. In Tables 1 to 3, being dispersed as single fibers was denoted as "single fiber dispersion".

[0120] (4)Content ratio (mass %) of the polymer elastomer in artificial leather The content ratio of polyurethane in artificial leather was measured and calculated by the above method.

[0121] (5)Areal density (g / m 2 ), thickness (μm), apparent density (g / cm 3 ) These values were measured and calculated by the above method respectively.

[0122] (6)Surface roughness Sa (μm) of artificial leather The surface roughness Sa (μm) of artificial leather was measured and calculated by using the "One-shot 3D measurement macroscope VR-3200" manufactured by Keyence Corporation as a non-contact surface roughness and shape measuring machine and by the above method.

[0123] (7)X-ray diffraction intensity I (-105) (unitless) of the (-105) plane measured by wide-angle X-ray, X-ray diffraction intensity I (100) (unitless) of the (100) plane measured by wide-angle X-ray, ratio Z These values were measured and calculated by using the "D8 ADVANCE" manufactured by Bruker Japan Co., Ltd. as an X-ray diffractometer and by the above method. In Tables 1 to 3, these values were abbreviated as "I (-105) ", "I (100) ", and "ratio Z" respectively.

[0124] (8)Determination of whether the surface has raised hairs and the number of fiber ends (pieces) observed from a 200-μm square field of view Regarding these, as a scanning electron microscope, the "VHX-D510 type" manufactured by Keyence Corporation was used and evaluated by the above method.

[0125] (9) Determination of whether it is a surface provided with a resin layer and the thickness (μm) of the resin layer Regarding these, as a scanning electron microscope, the "VHX-D510 type" manufactured by Keyence Corporation was used and evaluated by the above method.

[0126] (10) Maximum heat absorption rate q-max value (W / cm 2 ) As a quantitative evaluation of the contact cold feeling, the maximum heat absorption rate (q-max value) was measured using the "Precision and Rapid Thermal Physical Property Measuring Device (KES-F-M7 Thermo Lab II type)" manufactured by Kato Tech Co., Ltd. The measurement was performed with any one of the surfaces with raised hairs of artificial leather, the surface provided with a resin layer, and the surface with raised hairs and provided with a resin layer as the measurement surface, at room temperature of 20°C and humidity of 65%RH, and setting the temperature difference between the temperature detector and the measurement surface of the artificial leather to 10°C for measurement.

[0127] (11) Sensory evaluation of contact cold feeling As a qualitative evaluation of the contact cold feeling, any one of the surfaces with raised hairs of artificial leather, the surface provided with a resin layer, and the surface with raised hairs and provided with a resin layer, which had been left in a room at room temperature of 20°C and humidity of 65%RH for 24 hours, was touched with the palm of the hand by 10 ordinary consumers as subjects. Then, the contact cold feeling felt by each subject was judged according to the following criteria. A: An obvious cold feeling was given. B: (Between A and C) C: No cold feeling was obtained, and no warm feeling was felt either. D: (Between C and E) E: A warm feeling was felt. (12) Breaking strength per unit area As an index of the formability of artificial leather, in accordance with JIS L 1096 8.14.1 (2020) "Tensile Strength and Elongation" (Method A: Strip Method), with a test piece width of 25 mm, a gripping interval of 100 mm, and a tensile speed of 100 mm / min, the breaking strength was measured, and the breaking strength (N) was divided by the basis weight of the artificial leather (g / m 2 ) and the value was rounded to the third decimal place to obtain the breaking strength normalized per unit basis weight (N / (g / m 2 ).

[0128] (13) Evaluation of Texture Samples of artificial leather cut into 20×20 cm were prepared. Then, the appearance when bent inward with the central part as the boundary and the appearance when grasped were judged according to the following criteria. A: When bent, it bent in a rounded manner without the occurrence of dimples or wrinkles. Also, it had excellent drapability. B: When bent, it bent in a rounded manner, but fine and dense fold dimples occurred. It had excellent drapability. C: When bent, it bent by bending and fine and delicate fold dimples occurred. Its drapability was slightly inferior. D: When bent, it bent by bending, and thick dimples or deep wrinkles occurred. Also, its drapability was inferior. E: It had a texture with extremely low fullness.

[0129] [Resins used, etc.] The resins, etc. used in the examples and comparative examples are as follows.

[0130] (1) Polyester-based resins · Polyethylene terephthalate: It is a homopolymer with an intrinsic viscosity of 0.65. It was denoted as "PET" in Tables 1 to 3.

[0131] [Example 1] (Process of forming a web) The molten polyethylene terephthalate was discharged from a circular discharge hole with a hole diameter of 0.10 mm at the die at a single-hole discharge rate of 0.10 g / min. Then, while blowing air at 15 °C at a flow rate of 30.0 m / min from the discharge hole onto the polyethylene terephthalate in the region from 50 mm to 500 mm, a yarn was formed, and 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 hole and the inlet was 700 mm. Then, by collecting the drawn polyethylene terephthalate on a net conveyor under suction, a web composed of fibers with an average single fiber diameter of 4.0 μm and a cross-sectional irregularity degree of 1.00 was obtained. Note that the fibers were in a state of being dispersed as single fibers.

[0132] (Step of forming a nonwoven fabric) Next, two of the obtained webs were stacked and subjected to a heat press treatment (dry heat press). With the surface temperature of the upper plate being 180 °C and the surface temperature of the lower plate being 180 °C, a clearance was provided so that the apparent density of the resulting nonwoven fabric became 0.25 g / cm 3 and a nonwoven fabric was obtained by performing a heat press for 10 seconds.

[0133] (Step of forming a polymer elastomer-imparted sheet) Then, an aqueous dispersion type polyurethane liquid containing polyether diol as a polymer diol, aromatic diisocyanate as an organic diisocyanate, and ethylene glycol as a chain extender was prepared. After immersing the web etc. in this aqueous dispersion type polyurethane liquid, polyurethane was imparted by a dry coagulation method of drying at 120 °C so that the content ratio of the polymer elastomer in the artificial leather became 33 mass%, and a polymer elastomer-imparted sheet was obtained.

[0134] (Step of forming a surface with raised hairs etc.) Furthermore, one surface of this polymer elastomer-imparted sheet was ground with 240-grit sandpaper to form a surface with raised hairs. Then, as post-processing, dyeing was performed at 130 °C using disperse dyes in a liquid flow dyeing machine to obtain artificial leather. The apparent density of this artificial leather was 0.38 g / cm 3 It was as follows. The results are shown in Table 1.

[0135] [Example 2] An artificial leather was obtained in the same manner as in Example 1, except that (the step of forming a web) was replaced with the following. The results are also shown in Table 1.

[0136] (The step of forming a web) The melted polyethylene terephthalate was discharged from a circular discharge hole with a hole diameter of 0.10 mm at the discharge port of the die at a single-hole discharge rate of 0.10 g / min. Then, while blowing air at 15 °C at a flow rate of 30.0 m / min in the region from 50 mm to 500 mm from the discharge hole to the polyethylene terephthalate, a yarn was formed, and after roller traction at a spinning speed of 1600 m / min, fibers with an average single fiber diameter of 4.0 μm and an irregularity degree of the cross-section of 1.00 were produced under the condition of a draw ratio of 2.9 times. After cutting these fibers so that the fiber length became 5 mm, they were dispersed in water, and a web was obtained by the papermaking method. Note that the fibers were in a state of being dispersed as single fibers.

[0137] [Example 3] (In the step of forming a non-woven fabric), an artificial leather was obtained in the same manner as in Example 1, except that the clearance was changed so that the apparent density of the obtained non-woven fabric became 0.15 g / cm 3 The apparent density of this artificial leather was 0.23 g / cm 3 It was as follows. The results are also shown in Table 1.

[0138] [Example 4] (In the step of forming a non-woven fabric), an artificial leather was obtained in the same manner as in Example 1, except that the clearance was changed so that the apparent density of the obtained non-woven fabric became 0.35 g / cm 3 The apparent density of this artificial leather was 0.53 g / cm3 It was. The results are shown together in Table 1.

[0139] [Table 1]

[0140] [Comparative Example 1] (Step of forming a web) The above-mentioned polyethylene terephthalate was used as the island component, and polystyrene (denoted as PS in Table 2) was used as the sea component. Each was melted in an extruder, measured so that the mass ratio of the island component to the sea component was 80:20, and from the discharge holes of a spinneret capable of forming a cross-section in which 16 island components with a uniform cross-sectional area were distributed in the sea component, sea-island composite fibers were discharged at a single-hole discharge rate of 2.00 g / min. Thereafter, air at 15°C or lower was blown at a speed of 0.5 m / sec in the region 100 to 500 mm from the discharge holes against the melted island component and sea component, and traction was performed with air at 15°C so that the spinning speed became 4600 m / min. Also, the distance between the discharge holes and the inlet was 700 mm. Then, the tractioned composite fibers were collected on a net conveyor under suction to obtain a composite fiber web.

[0141] (Step of forming a non-woven fabric) Two sheets of the obtained composite fiber web were stacked, immersed in trichloroethylene to dissolve and remove the sea component, and a de-sea sheet composed of fibers with an average single fiber diameter of 4.0 μm and a cross-sectional irregularity degree of 1.00 was obtained. Heat press treatment was performed on this de-sea sheet under the same conditions as in Example 1 to obtain a non-woven fabric. Note that the fibers were not in a state of being dispersed as single fibers, and many bundled fibers were observed.

[0142] (Step of forming a sheet with a polymer elastomer imparted) To the non-woven fabric thus obtained, the water-dispersible polyurethane liquid used in Example 1 was adhered by the dip / nip method so that 33% by mass of the polyurethane resin was attached, and a sheet with a polymer elastomer imparted was obtained.

[0143] (Step of forming a surface with raised hairs, etc.) A surface having pile was formed on one surface in the same manner as in Example 1, and post-processing (dyeing) was performed to obtain artificial leather. The results are also shown in Table 2.

[0144] [Comparative Example 2] (Step of forming a web) A web was obtained in the same manner as in Example 2.

[0145] (Step of forming a non-woven fabric) Two layers of the obtained webs were prepared, and a fabric composed of fibers having an average single fiber diameter of 15.0 μm (resin constituting the fibers: polyethylene terephthalate, filament yarn, twist number: 2500 T / m) was inserted between them to obtain a laminated sheet. The obtained laminated sheet was subjected to water jet punching (denoted as "WJP" in Table 2) at a pressure of 10 MPa, and the front and back were alternately treated 4 times to obtain a non-woven fabric.

[0146] (Step of forming a sheet with a polymer elastomer) The water-dispersible polyurethane liquid used in Example 1 was adhered to the non-woven fabric thus obtained by the dip / nip method to deposit 33% by mass of polyurethane resin, thereby obtaining a sheet with a polymer elastomer.

[0147] (Step of forming a surface with pile, etc.) Raising treatment and post-processing (dyeing) were performed in the same manner as in Example 1. Further, with the surface having pile facing up, heat press treatment (dry heat press) was performed on the obtained artificial leather at an upper plate temperature of 110°C, a lower plate temperature of 110°C, and a press pressure of 17.7 kPa for 1 minute. The results are shown in Table 2.

[0148] [Comparative Example 3] (In the step of forming a non-woven fabric), when two of the obtained webs were stacked and heat press treatment was performed, after stacking two of the obtained webs, a non-woven fabric was obtained by performing water jet punching at a pressure of 20 MPa and alternately treating the front and back 4 times. An artificial leather was obtained in the same manner as in Example 1 except for this. The results are also shown in Table 2.

[0149] [Comparative Example 4] In the step of forming the web, a synthetic leather was obtained in the same manner as in Example 1, except that the web was discharged from the discharge holes at a single-hole discharge rate of 0.50 g / min to obtain a web made of fibers having an average single fiber diameter of 10.0 μm. The results are also shown in Table 2.

[0150] [Table 2]

[0151] [Example 5] In the step of forming a surface having raised hairs or the like, instead of providing a surface having raised hairs on one surface of the polymer elastomer-imparted sheet, a resin layer formed and processed by the following procedure was placed on one surface of the polymer elastomer-imparted sheet. With the resin layer facing up, dry heat pressing was performed at a top plate temperature of 110 °C, a bottom plate temperature of 25 °C, and a pressing pressure of 20.0 kPa for 1 minute for crimping. Then, a synthetic leather was obtained in the same manner as in Example 1, except that the release paper was further peeled off. The results are also shown in Table 3.

[0152] (Step of forming the resin layer) A water-dispersible polyurethane liquid containing polycarbonate diol as a polymer diol, aromatic diisocyanate as an organic diisocyanate, and ethylene glycol as a chain extender, and a carbon black-based black pigment were mixed with a mixer to prepare a resin liquid for forming the resin layer. This resin liquid was applied in a sheet shape on release paper with a comma coater and treated at 100 °C for 3 minutes with a dryer to form a non-porous resin layer having a thickness of 70 μm. Next, a polycarbonate-based polyurethane resin as an adhesive was applied to the surface of the resin film using a comma coater and heated at 100 °C for 1 minute with a dryer.

[0153] [Example 6] In the step of forming a surface having raised hairs or the like in Example 5, a synthetic leather having a resin layer formed on the surface was obtained in the same manner as in Example 5, except that the resin layer was formed on one surface of the polymer elastomer-imparted sheet formed in Example 2 instead of the polymer elastomer-imparted sheet formed in Example 1. The results are also shown in Table 3.

[0154] [Comparative Example 5] In Example 5 (formation of the resin layer forming sheet for forming a surface having erected hairs, etc.), an artificial leather having a resin layer formed on its surface was obtained in the same manner as in Example 5, except that the polymer elastomer-imparted sheet formed in Comparative Example 1 was used instead of the polymer elastomer-imparted sheet formed in Example 1. The results are also shown in Table 3.

[0155] [Table 3]

[0156] As shown in Tables 1 and 3, for the artificial leathers of Examples 1 to 6, excellent contact cool feeling performance was exhibited even without imparting a functional material to the fiber surface. On the other hand, as shown in Tables 2 and 3, for the artificial leathers of Comparative Examples 1 to 3 and 5, the results were inferior in contact cool feeling performance. Further, for the artificial leather of Comparative Example 4, although it was excellent in contact cool feeling performance, the texture was inferior.

Claims

1. An artificial leather comprising a non-woven fabric made of a polyester resin and containing fibers having an average single fiber diameter of 2.0 μm or more and 7.0 μm or less as main components, and a polymer elastomer, wherein the fibers are dispersed as single fibers, wherein at least one surface of the artificial leather is any one of a surface having pile, a surface provided with a resin layer, and a surface having pile and provided with a resin layer, wherein the arithmetic mean height Sa of the one surface is 10 μm or less, Furthermore, 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 ratio Z of the X-ray diffraction intensity I of the (100) plane measured with wide-angle X-rays （１００） is 0.010 or less, artificial leather. Z = I （－１０５） / I （１００） ... (Equation 1)

2. The artificial leather according to claim 1, wherein the fibers are long fibers.

3. The artificial leather according to claim 1 or 2, wherein the degree of cross-sectional irregularity of the fibers is 1.00 or more and 1.15 or less.

4. The artificial leather according to claim 1 or 2, wherein the content ratio of the polymer elastomer in the artificial leather is 5% by mass or more and 50% by mass or less.

5. The apparent density is 0.25 g / cm ３ or more and 0.50 g / cm ３ or less. The artificial leather according to claim 1 or 2.

6. The artificial leather according to claim 1 or 2, further comprising a woven or knitted fabric composed of fibers having an average single fiber diameter of 5.0 μm or more and 25.0 μm or less.

7. A step of forming a web made of a polyester resin and containing fibers having an average single fiber diameter of 2.0 μm or more and 7.0 μm or less as main components; a step of thermally pressing the web at a temperature of 80°C or more and 230°C or less for a time of 5 seconds or more and 120 seconds or less to form a non-woven fabric; a step of applying a polymer elastomer to the non-woven fabric to form a polymer elastomer-applied sheet; a step of forming, on at least one surface of the polymer elastomer-applied sheet, any one of a surface having pile, a surface provided with a resin layer, and a surface having pile and provided with a resin layer, and making the arithmetic mean height Sa of the one surface 10 μm or less. Furthermore, the X-ray diffraction intensity I of the (-105) plane measured by wide-angle X-rays calculated by the following formula 1 （－１０５） and the ratio Z of the X-ray diffraction intensity I of the (100) plane measured by wide-angle X-rays （１００） is 0.010 or less, a method for manufacturing artificial leather. Z = I （－１０５） / I （１００） ... (Equation 1).

8. The method for manufacturing an artificial leather according to claim 7, wherein the web is formed by a spunbond method.

9. An interior material for a vehicle, characterized by being made using the artificial leather according to claim 1 or 2.

10. A seat, characterized by being made using the artificial leather according to claim 1 or 2.

11. A clothing, characterized by being made using the artificial leather according to claim 1 or 2.

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