JP7347078B2 - Artificial leather and its manufacturing method - Google Patents

Description

The present invention relates to artificial leather that is made of a fiber entangled body made of a thermoplastic resin and an elastic polymer, and that has both excellent fastness and mechanical properties, especially in non-dark colors.

BACKGROUND OF THE INVENTION Artificial leather that resembles natural leather and is composed of a fiber entanglement mainly made of a thermoplastic resin and an elastic polymer has superior characteristics compared to natural leather, such as high durability and uniform quality. Therefore, it is used not only as a material for clothing, but also in various fields such as vehicle interior materials, interiors, shoes, and clothing. Artificial leather has various required properties depending on the field in which it is used. For example, when used as a vehicle interior material, it is required to have high light resistance that can withstand actual use.

The colors of artificial leather used for vehicle interior materials are mainly dark colors such as black and dark gray, but non-dark colors such as beige and light gray are also increasingly being used. . These are often adjusted to the desired color by dyeing, but when using ultrafine fibers as fiber entanglements, the concentration of dye is lower than that of normal fibers due to the high specific surface area of ultrafine fibers. It is necessary to significantly increase the staining. In that case, the fastness of the artificial leather, such as light fastness and abrasion fastness, decreases, so a method for imparting excellent fastness to artificial leather using ultrafine fibers has been sought for some time.

To address the above issues, a method of adding pigments such as carbon black to ultrafine fibers, a method of using so-called spun-dyed fibers, has been proposed as a means of imparting excellent robustness to artificial leather using ultrafine fibers as fiber entanglements. have been proposed (for example, see Patent Documents 1 to 4).

Special Publication No. 2011-523985 Japanese Patent Application Publication No. 2018-178297 Japanese Patent Application Publication No. 2018-178297 Japanese Patent Application Publication No. 2000-144583

In the techniques disclosed in Patent Documents 1 to 4, it is possible to achieve excellent light fastness by using pigments that have better light fastness than dyes. However, in the technologies disclosed in Patent Document 1 and Patent Document 2, carbon black is used as a pigment, so when the color of artificial leather is dark such as black, the dye reduction effect is large and good results are obtained. While artificial leather with light fastness can be obtained, in the case of non-dark colors, the pigment content or dyed fiber content is originally low, and as a result, the dye reduction effect is also small. Furthermore, the light fastness is also insufficient.

In addition, in the technology disclosed in Patent Document 3, it is necessary to use organic pigments for artificial leather with non-dark colors, and in order to prevent the pigments from falling off during the manufacturing process, organic solvents are used. Not only is its use limited, but its robustness as an artificial leather may not be sufficient compared to artificial leather using inorganic pigments.

Therefore, the present invention has been made in view of the above circumstances, and its purpose is to provide an excellent non-dark color, which is made of a fiber entangled body made of a thermoplastic resin and a polymeric elastomer. The purpose of the present invention is to provide artificial leather with robustness.

As a result of repeated studies by the present inventors to achieve the above object, it has been found that when the technology disclosed in Patent Document 4 is applied to artificial leather, pigments are contained in the fibers constituting the artificial leather. Although it was possible to achieve a certain level of light fastness, it was also found that the mechanical properties of the fibers deteriorated, such as the yarn strength of the fibers decreasing. Therefore, as a result of further investigation, we found that when using chromatic fine particle oxide pigments with an average particle diameter within a specific range as inorganic pigments, depending on the dispersion form in the ultrafine fibers, the yarn strength of the ultrafine fibers may decrease. I found out that it can be suppressed. As a result, even in artificial leather with a non-dark color that could not be easily manufactured in the past, it exhibits excellent color development while suppressing the decrease in thread strength of ultra-fine fibers, resulting in excellent durability. We have discovered that it is possible to obtain artificial leather that has both physical and mechanical properties.

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

That is, the artificial leather of the present invention is an artificial leather made of a fiber entanglement made of ultrafine fibers having an average single fiber diameter of 1.0 μm or more and 10.0 μm or less, and a polymeric elastic material, in which the ultrafine fibers are , consisting of a thermoplastic resin containing a chromatic fine particle oxide pigment having an average secondary particle diameter of 0.05 μm or more and 0.30 μm or less, among the ultrafine fibers, a thermoplastic resin that does not contain the chromatic fine particle oxide pigment; The resin region (A) is included in the thermoplastic resin region (B) containing the chromatic fine particle oxide pigment .

According to a preferred embodiment of the artificial leather of the present invention, it is measured based on "a) 1st exposure method" of "7.2 Exposure method" of JIS L0843: 2006 "Test method for color fastness to xenon arc lamp light" Light fastness is grade 4 or higher.

According to a preferred embodiment of the artificial leather of the present invention, it contains a dye, and the color difference (ΔE _ab ) before and after dedying is 15 or less.

According to a preferred embodiment of the artificial leather of the present invention, the thermoplastic resin is made of a polyester resin.

According to a preferred embodiment of the artificial leather of the present invention, the polymer elastic body is made of polyurethane.

According to a preferred embodiment of the artificial leather of the present invention, the ratio (S B ) of the area (S _{B ) of the thermoplastic resin region (B} ) containing the chromatic fine particle oxide pigment to the area (S _F ) of the microfibers _is /S _F ) is 5% or more and 50% or less.

In addition, in the method for producing artificial leather of the present invention, a thermoplastic resin containing a chromatic fine particle oxide pigment having an average primary particle size of 0.01 μm or more and 0.15 μm or less is used as an island portion, and an easily soluble polymer is used as an island portion. After carrying out the process of manufacturing ultrafine fiber-expressing fibers having a sea-island composite structure, a fibrous base material made of ultrafine fibers is formed, and an elastic polymer is further added to the fibrous base material. The above-mentioned artificial leather is obtained.

According to a preferred embodiment of the method for producing artificial leather of the present invention, the artificial leather described above or the artificial leather obtained by the method for producing artificial leather described above is further dyed.

According to the present invention, artificial leather having excellent fastness can be obtained. In addition, it is possible to obtain artificial leather that has both excellent color development and mechanical properties, which have been problems with conventional artificial leather made of ultrafine fibers containing inorganic pigments. Furthermore, the artificial leather of the present invention has a soft touch similar to natural leather and excellent durability, and can be used in a wide range of applications from furniture, chairs and vehicle interior materials to clothing, but in particular its excellent light resistance. It is suitable for use in vehicle interior materials due to its durability and durability.

The artificial leather of the present invention is an artificial leather comprising a fiber entanglement consisting of ultrafine fibers having an average single fiber diameter of 1.0 μm or more and 10.0 μm or less, and a polymeric elastic body, The ultrafine fibers are made of a thermoplastic resin containing a chromatic fine particle oxide pigment having an average secondary particle diameter of 0.05 μm or more and 0.30 μm or less , and of the ultrafine fibers, the chromatic fine particle oxide pigment is The region (A) of the thermoplastic resin not containing the thermoplastic resin is included in the region (B) of the thermoplastic resin containing the chromatic fine particle oxide pigment.

The constituent elements will be described in detail below, but the present invention is not limited to the scope described below unless it exceeds the gist thereof.

[Fiber entangled body]
As the thermoplastic resin constituting the fiber entangled body used in the present invention, polyester resins and polyamide resins are preferably used from the viewpoint of durability, especially mechanical strength, and polyester resins with excellent heat resistance are preferably used. It is more preferable to use it.

Examples of the polyester resin include polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, and polyethylene-1,2- Examples include bis(2-chlorophenoxy)ethane-4,4'-dicarboxylate. Among them, polyethylene terephthalate, which is most commonly used, or a polyester copolymer mainly containing ethylene terephthalate units is preferably used.

In addition, as the polyester resin, a single polyester or two or more different polyesters may be used, but when two or more different polyesters are used, a phase difference between the two or more components may be used. From the viewpoint of solubility, the difference in intrinsic viscosity (IV value) of the polyesters used is preferably 0.50 or less, more preferably 0.30 or less.

In the present invention, the intrinsic viscosity is calculated by the following method.
(1) Dissolve 0.8 g of sample polymer in 10 mL of orthochlorophenol.
(2) The relative viscosity η _r is calculated using the following formula using an Ostwald viscometer at a temperature of 25° C., and rounded to the second decimal place.
・η _r =η/η ₀ = (t×d)/(t ₀ ×d ₀ )
・Intrinsic viscosity (IV value) = 0.0242η _r +0.2634
(Here, η is the viscosity of the polymer solution, η ₀ is the viscosity of orthochlorophenol, t is the falling time of the solution (seconds), d is the density of the solution (g/cm ³ ), and t ₀ is the falling of orthochlorophenol. Time (seconds) and d ₀ represent the density of orthochlorophenol (g/cm ³ ), respectively.

The cross-sectional shape of the ultrafine fibers is preferably round from the viewpoint of processing operability, but polygons such as ellipse, flat and triangular shapes, sector shapes, cross shapes, hollow shapes, Y-shape, T-shape, and U-shape are also suitable. It is also possible to adopt a cross-sectional shape with an irregular cross-section such as a mold.

In addition to chromatic fine particle oxide pigments, the thermoplastic resin constituting the ultrafine fibers may contain inorganic particles such as titanium oxide, lubricants, and heat stabilizers, depending on various purposes, to the extent that they do not impede the purpose of the present invention. , an ultraviolet absorber, a conductive agent, a heat storage agent, an antibacterial agent, etc. can be added.

It is important that the average single fiber diameter of the ultrafine fibers is 1.0 μm or more and 10.0 μm or less. By setting the average single fiber diameter of the ultrafine fibers to 1 μm or more, preferably 1.5 μm or more, more preferably 2.0 μm or more, excellent color development after dyeing, light fastness and abrasion fastness, and stability during spinning can be achieved. be effective. On the other hand, by setting the thickness to 10.0 μm or less, preferably 6.0 μm or less, and more preferably 4.5 μm or less, artificial leather with excellent surface quality that is dense and soft to the touch can be obtained.

In the present invention, the average single fiber diameter of the ultrafine fibers is defined as the average single fiber diameter by taking a scanning electron microscope (SEM) photograph of a cross section of artificial leather, randomly selecting 10 circular or nearly circular elliptical ultrafine fibers, and calculating the single fiber diameter. It shall be calculated by measuring, calculating the arithmetic average value of 10 pieces, and rounding the value to the second decimal place. However, when ultrafine fibers with an irregular cross section are adopted, the diameter of the single fibers shall be determined by first measuring the cross-sectional area of the single fibers and calculating the diameter when the cross section is assumed to be circular.

In the present invention, it is important that the thermoplastic resin constituting the ultrafine fibers contains a chromatic fine particle oxide pigment having an average secondary particle diameter of 0.05 μm or more and 0.30 μm or less.

The secondary particle size herein refers to the particle size in a state where the chromatic fine particle oxide pigment is aggregated and present in the ultrafine fibers.

By setting the average secondary particle diameter (average secondary particle diameter) of the chromatic fine particle oxide pigment to 0.05 μm or more, preferably 0.10 μm or more, the chromatic fine particle oxide pigment can be held inside the ultrafine fibers. As a result, falling off from the ultrafine fibers is suppressed. By setting the diameter to 0.30 μm or less, preferably 0.25 μm or less, the yarn strength will be excellent, and the stability during spinning (suppression of yarn breakage) and mechanical properties of the artificial leather will be excellent.

In the present invention, the average secondary particle diameter shall be calculated by the following method.
(1) An ultrathin section with a thickness of 5 to 10 μm is prepared in the cross-sectional direction of the plane perpendicular to the longitudinal direction of the ultrafine fiber.
(2) Observe the cross section of the fiber in the ultrathin section using a transmission electron microscope (TEM) at 10,000 times magnification.
(3) Using image analysis software, measure the circle equivalent diameter of the pigment particle size included in the 2.3 μm x 2.3 μm field of view of the observed image at 20 points.
(4) Calculate the average value (arithmetic mean) of the measured particle diameters at 20 points.

The chromatic fine particle oxide pigment in the present invention refers to a chromatic fine particle oxide pigment, and does not include white oxide pigments such as zinc oxide or titanium oxide, or black oxide pigments such as magnetite. In addition, in the present invention, the above-mentioned white oxide pigment, black oxide pigment, and other organic pigments may be present in the ultrafine fibers. However, the content of components other than the chromatic fine particle oxide pigment in the ultrafine fibers shall be 20% by mass or less based on the content of the chromatic fine particle oxide pigment.

As the chromatic fine particle oxide pigment, known pigments close to the target color can be used, such as iron oxyhydroxide (e.g. "TM Yellow 8170" manufactured by Dainichiseika Co., Ltd.), iron oxide, etc. (Example: "TM Red 8270" manufactured by Dainichiseika Chemical Co., Ltd.), cobalt aluminate (Example: "TM Blue 3490E" manufactured by Dainichiseika Chemical Co., Ltd.), chromium oxide, etc.

Furthermore, the chromatic fine particle oxide pigment is unevenly distributed on the outer periphery of the ultrafine fiber, more specifically, the region (A) of the thermoplastic resin that does not contain the chromatic fine particle oxide pigment is It is preferable that it be included in the plastic resin region (B) in order to achieve both excellent color development and yarn strength.

In addition, from the viewpoint of excellent color development and yarn strength, the area of the region (B) where the chromatic fine particle oxide pigment exists (abbreviated as S _B ) is compared to the area of the ultrafine fiber (abbreviated as S _F ). The ratio (S _B /S _F ) is preferably 5% or more and 50% or less. By setting S _B /S _F to 5% or more, preferably 10% or more, more preferably 15% or more, the area (B) where the chromatic fine particle oxide pigment exists is changed to the area where the chromatic fine particle oxide pigment exists. By setting the content to 50% or less, preferably 45% or less, and more preferably 40% or less, the chromatic color in the ultrafine fibers can be completely covered and has excellent coloring properties. The amount of fine particle oxide pigment can be suppressed, and a decrease in yarn strength can be suppressed.

In the present invention, the ratio (S _B /S _F ) of the area (S B ) of the region ( _B ) where the chromatic fine particle oxide pigment exists to the area (S _F ) of the ultrafine fibers is calculated by the following method. shall be carried out.
(1) An ultrathin section with a thickness of 5 to 10 μm is prepared in the cross-sectional direction of the plane perpendicular to the longitudinal direction of the ultrafine fiber.
(2) Observe the fiber cross section in the ultra-thin section using a transmission electron microscope (TEM) at 1000x to 5000x magnification.
(3) Measure the area (S _F ) of any ultrafine fiber using image analysis software.
(4) For the ultrafine fiber whose area was measured in (3), measure the distance X from the fiber surface to the furthest chromatic fine particle oxide pigment, and measure the distance The area (S _A ) of the pigment-free area is measured.
(5) Calculate the area of the region containing the chromatic fine particle oxide pigment (S _B ) using the following formula - Area of the region containing the chromatic fine particle oxide pigment (S _B ) = Area of the ultrafine fiber (S _F ) - Area of region not containing chromatic fine particle oxide pigment (S _A )
(6) The area (S _B ) obtained in (5) was divided by the area (S _F ) obtained in (3), and the result (S _B /S _F ) was measured at n=5, and the obtained The arithmetic mean value (%) of the values rounded to the first decimal place is calculated as the area (S B ) of _{the region (B) where the chromatic fine particle oxide pigment exists with respect to the area (S F )} of the ultrafine fibers. Let the ratio be (S _B /S _F ).

The proportion of the chromatic fine particle oxide pigment contained in the ultrafine fiber can be adjusted as appropriate depending on the type of the chromatic fine particle oxide pigment and the target color, but it is 0.1% by mass based on the mass of the ultrafine fiber. The content is preferably in the range of 5.0% by mass or more. By setting the above ratio to 0.1% by mass or more, preferably 0.3% by mass or more, and more preferably 0.5% by mass or more, excellent color development can be achieved. On the other hand, when the content is 5.0% by mass or less, preferably 3.0% by mass or less, and more preferably 2.0% by mass or less, excellent yarn strength can be obtained.

The content of chromatic fine particle oxide shall be calculated by the following method.
(1) Remove the polymer elastic body from the artificial leather and isolate the fiber entangled body consisting of ultrafine fibers.
(2) The chromatic fine particle oxide contained in the ultrafine fibers is isolated using a solvent that can dissolve the thermoplastic resin constituting the ultrafine fibers.
(3) The content (mass %) of the chromatic fine particle oxide is calculated by dividing the mass of the chromatic fine particle oxide by the mass of the fiber entangled body.

When the chromatic fine particle oxide pigment contained in the thermoplastic resin is unevenly distributed near the outer periphery of the ultrafine fiber, the chromatic fine particle oxide pigment contained in the thermoplastic resin is unevenly distributed near the outer periphery of the ultrafine fiber. If the proportion of the chromatic fine particle oxide pigment is , more excellent coloring properties will be exhibited. Alternatively, since the proportion of the chromatic fine particle oxide pigment required to achieve the same level of color development is reduced, an artificial leather with better mechanical properties can be obtained.

One of the constituent elements of the artificial leather of the present invention is a fiber entangled body containing, as a constituent element, a nonwoven fabric made of ultrafine fibers made of the above-mentioned thermoplastic resin.

In the present invention, a "fiber entangled body containing a nonwoven fabric as a constituent element" refers to an aspect in which the fiber entangled body is a nonwoven fabric, and a fiber entangled body formed by entangling and integrating a nonwoven fabric and a woven fabric as described below. This refers to aspects such as those in which the fiber entangled body is entangled and integrated with a base material other than a nonwoven fabric and a woven fabric.

By using a fiber entangled body containing nonwoven fabric as a component, a uniform and elegant appearance and texture can be obtained when the surface is raised.

The forms of nonwoven fabrics include long fiber nonwoven fabrics mainly composed of filaments and short fiber nonwoven fabrics mainly composed of fibers of 100 mm or less. It is preferable to use a long-fiber nonwoven fabric as the fibrous base material, since it is possible to obtain artificial leather with excellent strength. On the other hand, when using a short fiber nonwoven fabric, it is possible to increase the number of fibers oriented in the thickness direction of the artificial leather compared to the case of a long fiber nonwoven fabric, giving a high density feeling to the surface of the artificial leather when raised. can be made to have

When a short fiber nonwoven fabric is used, the fiber length of the ultrafine fibers is preferably 25 mm or more and 90 mm or less. By setting the fiber length to 90 mm or less, more preferably 80 mm or less, and still more preferably 70 mm or less, good quality and texture can be achieved. On the other hand, by setting the fiber length to 25 mm or more, more preferably 35 mm or more, and even more preferably 40 mm or more, artificial leather with excellent abrasion resistance can be obtained.

The basis weight of the nonwoven fabric constituting the artificial leather according to the present invention is measured according to "6.2 Mass per unit area (ISO method)" of JIS L1913:2010 "General nonwoven fabric testing method", and is 50 g/m ² or more 400 g/m2 The range is preferably m ² or less. By setting the basis weight of the nonwoven fabric to 50 g/m ² or more, more preferably 80 g/m ^{2 or} more, it is possible to obtain artificial leather with a full feeling and excellent texture. On the other hand, by setting it to 400 g/m ² or less, more preferably 300 g/m ² or less, a flexible artificial leather with excellent moldability can be obtained.

In the artificial leather of the present invention, for the purpose of improving its strength and morphological stability, it is also preferable that a woven fabric is laminated inside or on one side of the nonwoven fabric and intertwined and integrated.

As for the type of fiber constituting the woven fabric used when the above-mentioned woven fabric is entangled and integrated, it is preferable to use filament yarn, spun yarn, mixed composite yarn of filament yarn and spun yarn, etc. From the viewpoint of mechanical strength, etc., it is more preferable to use a multifilament made of polyester resin or polyamide resin.

Further, from the viewpoint of mechanical strength, etc., the fibers constituting the above-mentioned woven fabric are preferably fibers that do not contain pigments.

The average single fiber diameter of the fibers constituting the fabric is preferably 1.0 μm or more and 50.0 μm or less. By setting the average single fiber diameter of the fibers constituting the fabric to 50.0 μm or less, more preferably 15.0 μm or less, and still more preferably 13.0 μm or less, not only can artificial leather with excellent flexibility be obtained, but also Even if the fibers of the fabric are exposed on the surface of the artificial leather, the difference in hue from the pigment-containing ultrafine fibers becomes small after dyeing, so the uniformity of the hue on the surface is not impaired. On the other hand, by setting the average single fiber diameter to 1.0 μm or more, more preferably 8.0 μm or more, even more preferably 9.0 μm or more, the shape stability of the product as artificial leather is improved.

In the present invention, the average single fiber diameter of the fibers constituting the woven fabric is determined by taking a scanning electron microscope (SEM) photograph of a cross section of the artificial leather, randomly selecting 10 fibers constituting the woven fabric, and calculating the single fiber diameter of the fibers. It shall be calculated by measuring, calculating the arithmetic average value of 10 pieces, and rounding the value to the second decimal place.

When the fibers constituting the above-mentioned woven fabric are multifilaments, the total fineness of the multifilaments is determined by "8.3.1 Fineness" in "8.3 Fineness" of JIS L1013:2010 "Chemical fiber filament yarn testing method". Fineness b) Measured by method B (simple method), and is preferably 30 dtex or more and 170 dtex or less.

By setting the total fineness of the yarns constituting the fabric to 170 dtex or less, more preferably 150 dtex or less, artificial leather with excellent flexibility can be obtained. On the other hand, by setting the total fineness to 30 dtex or more, not only the shape stability of the product as artificial leather is improved, but also the fibers constituting the woven fabric are This is preferable because it is less likely to be exposed on the surface of the artificial leather. At this time, it is preferable that the warp and weft multifilaments have the same total fineness.

Furthermore, the number of twists of the threads constituting the fabric is preferably 1000 to 4000 T/m. By setting the number of twists to 4000 T/m or less, more preferably 3500 T/m or less, still more preferably 3000 T/m or less, artificial leather with excellent flexibility can be obtained, and the number of twists to 1000 T/m or more, more preferably By setting it to 1500 T/m or more, more preferably 2000 T/m or more, it is possible to prevent damage to the fibers constituting the woven fabric when the nonwoven fabric and the woven fabric are entangled and integrated with a needle punch etc. This is preferable because it provides excellent mechanical strength.

[Elastic polymer]
The elastic polymer that constitutes the artificial leather of the present invention is a binder that holds the ultrafine fibers that constitute the artificial leather. , polyurethane, polyurethane, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), and acrylic resin. Among these, it is a preferred embodiment to use polyurethane as the main component. By using polyurethane, it is possible to obtain artificial leather that has a solid feel, a leather-like appearance, and physical properties that can withstand practical use. In addition, "being a main component" as used in the present invention means that the mass of polyurethane is more than 50% by mass with respect to the mass of the entire elastic polymer body.

When polyurethane is used in the present invention, either organic solvent-based polyurethane, which is used in a state dissolved in an organic solvent, or water-dispersed polyurethane, which is used in a state where it is dispersed in water, can be employed. Moreover, as the polyurethane, a polyurethane obtained by the reaction of a polymer diol, an organic diisocyanate, and a chain extender is preferably used.

In addition, depending on the purpose, various additives are added to the polymer elastomer, such as pigments such as carbon black, flame retardants such as ``phosphorus-based, halogen-based, and inorganic'', and ``phenol-based, sulfur-based, and phosphorus-based''. Antioxidants such as ``benzotriazole type, benzophenone type, salicylate type, cyanoacrylate type and oxalic acid anilide type'', UV absorbers such as ``hindered amine type and benzoate type'', polycarbodiimide It may contain hydrolysis stabilizers such as, plasticizers, antistatic agents, surfactants, coagulation regulators, dyes, and the like.

Generally, the content of the elastic polymer in artificial leather can be adjusted as appropriate, taking into account the type of elastic polymer used, the method of manufacturing the elastic polymer, and the texture and physical properties. In this case, the content of the elastic polymer is preferably 10% by mass or more and 60% by mass or less based on the mass of the fiber entangled body. By setting the content of the elastic polymer to 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, the bond between the fibers by the elastic polymer can be strengthened, The abrasion resistance of artificial leather can be improved. On the other hand, by setting the content of the polymeric elastomer to 60% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less, the artificial leather can be made more flexible. can.

[Artificial leather]
In the artificial leather of the present invention, it is a preferable embodiment that the surface has nape. The nap may be present only on the surface of the artificial leather, or it is also acceptable to have it on both sides. In the case where the surface has piloerection, the piloere formation has enough length and directional flexibility to produce so-called finger marks, which leave marks due to changes in the direction of the piloes when traced with a finger from the viewpoint of design effect. It is preferable.

More specifically, the nap length on the surface is preferably 100 μm or more, more preferably 150 μm or more, and even more preferably 200 μm or more. In particular, when the woven fabric is entangled and integrated with the nonwoven fabric that constitutes the artificial leather, by setting the nap length on the surface within the above range, it is possible to sufficiently cover the fibers of the woven fabric near the surface of the artificial leather. It is preferable because it can be done. On the other hand, since the durability of the artificial leather against friction can be improved, the thickness is preferably 400 μm or less, and more preferably 350 μm or less. To determine the length of the nap on the surface, take a SEM photo of the cross section of the artificial leather at a magnification of 50x with the nap of the artificial leather standing on end using a lint brush, etc., and measure the height of the nap (layer consisting only of ultra-fine fibers) by 10 points. Calculated by measuring and calculating the average value.

The artificial leather of the present invention has a thickness of 0.2 mm or more as measured by "6.1.1 A method" in "6.1 Thickness (ISO method)" of JIS L1913:2010 "General nonwoven fabric test method". The range is preferably 1.2 mm or less. By setting the thickness of the artificial leather to 0.2 mm or more, more preferably 0.3 mm or more, and even more preferably 0.4 mm or more, it not only has excellent processability during manufacturing, but also has a full and excellent texture. It becomes something. On the other hand, by setting the thickness to 1.2 mm or less, more preferably 1.1 mm or less, still more preferably 1.0 mm or less, a flexible artificial leather with excellent moldability can be obtained.

The artificial leather of the present invention has a light fastness of grade 4 or higher as measured by "7.2 Exposure method a) 1st exposure method" of JIS L0843:2006 "Dyeing fastness test method against xenon arc lamp light" is preferred. By having a light fastness of grade 4 or higher, it is possible to prevent color fading during actual use.

In addition, the artificial leather of the present invention has been tested in "8.19.5 E method (Martindale method)" in "8.19 Abrasion strength and friction discoloration" of JIS L1096:2010 "Testing methods for textiles and knitted fabrics". In the measured abrasion resistance test, the press load is 12.0 kPa, and the weight loss of the artificial leather after being worn 20,000 times is preferably 10 mg or less, more preferably 8 mg or less, and 6 mg or less. It is more preferable that When the weight loss is 10 mg or less, contamination due to fluff falling during actual use can be prevented.

The artificial leather of the present invention preferably contains a dye, and further preferably has a color difference (ΔE _ab ) of 15 or less before and after dedying. The smaller the color difference before and after dedying, the smaller the amount of dye added, and the better the fastness of the artificial leather. The color difference (ΔE _ab ) before and after dedying is measured as follows, and is preferably 10 or less, more preferably 8 or less.
(1) Measure the surface brightness (L ^* value) and color coordinates (a ^* value, b ^* value) of the artificial leather before dedying. The surface brightness (L ^* value) and color coordinates (a ^* value, b ^* value) are measured using JIS Z8781, with the raised surface of the artificial leather as the measurement surface and the raised raised surface laid down using a lint brush etc. -4:2013 "Colorimetry - Part 4: CIE1976L ^* a ^* b ^* color space" L ^* value defined by "3.3 CIE1976 lightness index" and "3.4 CIELAB 1976 a ^* b ^* coordinates" , a ^* value, and b ^* value. In the present invention, the L ^* value, a ^* value, and b ^* value are measured 10 times using a spectrophotometer, and the arithmetic mean of the measurement results is calculated as the L ^* value, a ^* value, and b ^* value of the artificial leather. Adopt as value.
(2) For the artificial leather after dedying, measure the L ^* value, a ^* value, and b ^* value in the same manner as in (1). Note that the dye removal treatment of artificial leather can be performed by a known method. For example, when the dye is a disperse dye, the dye removal can be performed by repeatedly performing reduction washing with hydrosulfite.
(3) Regarding the L ^* value, a ^* value, and b ^* value before and after dedying obtained in (1) and (2), JIS Z8781-4:2013 "Colorimetry - Part 4: CIE1976L ^* a ^* b" The color difference ΔE _ab defined by ^" 3.12 CIELAB 1976 L ^* a ^* b ^* color difference" in "*Color space" is calculated.

The artificial leather of the present invention has a tensile strength measured according to "6.3.1 Tensile strength and elongation (ISO method)" of JIS L1913:2010 "General nonwoven fabric testing method" of 20 to 20 in any measurement direction. It is preferable that it is 200N/cm.

It is preferable that the tensile strength is 20 N/cm or more, more preferably 30 N/cm or more, and even more preferably 40 N/cm or more, since the artificial leather has excellent shape stability and durability. Moreover, when the tensile strength is 200 N/cm or less, more preferably 180 N/cm or less, and still more preferably 150 N/cm or less, the artificial leather has excellent moldability.

[Manufacturing method of artificial leather]
The artificial leather of the present invention is a sea-island composite in which the island part is a thermoplastic resin containing a chromatic fine particle oxide pigment with an average primary particle diameter of 0.01 μm or more and 0.15 μm or less, and the sea part is an easily soluble polymer. After carrying out the step of producing ultrafine fiber-expressing fibers having a structure, a fibrous base material made of ultrafine fibers is formed, and a polymer elastic body is further added to the fibrous base material to obtain the artificial leather. . The details of each step will be explained below.

<Process of manufacturing ultrafine fiber expression type fiber>
In this process, a sea-island composite structure is constructed in which the island part is a thermoplastic resin containing a chromatic fine particle oxide pigment with an average primary particle diameter of 0.01 μm or more and 0.15 μm or less, and the sea part is an easily soluble polymer. A microfiber-expressing fiber having the following characteristics is produced.

Ultra-fine fiber-expressing fibers are produced by forming thermoplastic resins with different solvent solubility into a sea part (easily soluble polymer) and a island part (hardly soluble polymer), and by dissolving and removing the sea part using a solvent or the like. A sea-island type composite fiber is used in which the island portions are ultrafine fibers. By using sea-island composite fibers, it is possible to create appropriate voids between the islands when removing the sea areas, that is, between the ultrafine fibers inside the fiber bundle, which is preferable from the viewpoint of the texture and surface quality of the artificial leather. . As a method for spinning ultrafine fiber-generating fibers having a sea-island composite structure, a method using a polymer mutual array in which a sea-island composite spinneret is used and spun by arranging sea parts and island parts mutually is a method that produces uniform fibers. This is preferable from the viewpoint that ultrafine fibers with a fineness of fibers can be obtained.

The island portion of the ultrafine fiber-generating fiber having a sea-island composite structure is preferably composed of two components: a core component that does not contain a chromatic fine particle oxide pigment and a sheath component that contains a chromatic fine particle oxide pigment.

When the island part is composed of two components, the core component and the sheath component, in order to both suppress the decrease in yarn strength of the ultrafine fibers and cover the chromatic fine particle oxide pigment with the sheath component, the island part has two components, the core component and the sheath component. The mass ratio is preferably in the range of 50:50 to 95:5.

When the island part has two components, a core component and a sheath component, the content of the chromatic fine particle oxide pigment of the sheath component is in the range of 0.5% by mass or more and 10.0% by mass or less based on the mass of the thermoplastic resin. It is preferable that there be. By setting the above ratio to 0.05% by mass or more, more preferably 0.8% by mass or more, artificial leather with excellent color development can be obtained. On the other hand, by setting the content to 10.0% by mass or less, more preferably 8.0% by mass or less, and still more preferably 6.0% by mass or less, it is possible to obtain artificial leather with high physical properties such as yarn strength.

As a method for incorporating chromatic fine particle oxide pigments into the island portion (or sheath component), spinning using only chips in which chromatic fine particle oxide pigments have been kneaded in thermoplastic resin in advance is also possible. Any of the methods of mixing a masterbatch kneaded with a colored fine particle oxide pigment and thermoplastic resin chips and spinning the mixture can be adopted. Among these, the method of mixing with thermoplastic resin chips using a masterbatch is preferred because it allows the amount of pigment contained in the ultrafine fibers to be adjusted as appropriate.

At this time, the chromatic fine particle oxide pigment contained has an average primary particle diameter of 0.01 μm or more and 0.15 μm or less. By doing so, when artificial leather is made, the ultrafine fibers can contain a chromatic fine particle oxide pigment having an average secondary particle diameter of 0.05 μm or more and 0.30 μm or less.

As the sea part of the sea-island type composite fiber, polyethylene, polypropylene, polystyrene, copolymerized polyester obtained by copolymerizing sodium sulfoisophthalic acid, polyethylene glycol, etc., polylactic acid, etc. can be used. Among these, polystyrene and copolymerized polyester are preferably used from the viewpoint of spinning properties, easy dissolution properties, and the like.

In the method for producing artificial leather of the present invention, when using a sea-island type conjugate fiber, it is preferable to use a sea-island type conjugate fiber whose island portion has a strength of 2.5 cN/dtex or more. When the strength of the island portion is 2.5 cN/dtex or more, more preferably 2.8 cN/dtex or more, still more preferably 3.0 cN/dtex or more, the abrasion resistance of the artificial leather can be improved.

In the present invention, the strength of the island portion of the sea-island composite fiber is calculated by the following method.
(1) Bundle 10 sea-island composite fibers with a length of 20 cm.
(2) After dissolving and removing the sea area from the sample in (1), air dry it.
(3) JIS L1013:2010 "Chemical fiber filament yarn test method""8.5 Tensile strength and elongation rate""8.5.1 Standard time test", grip length 5 cm, tensile speed 5 cm/min , the test is carried out 10 times under the condition of a load of 2N (N=10).
(4) The value obtained by rounding off the arithmetic mean value (cN/dtex) of the test results obtained in (3) to the second decimal place is the strength of the island portion of the sea-island composite fiber.

<Process of manufacturing fibrous base material>
In this step, a fibrous base material made of ultrafine fibers is formed.

First, the spun ultrafine fiber-expressing fibers are opened and then made into a fiber web using a cross wrapper or the like, and entangled to obtain a nonwoven fabric that is raw cotton. As a method of entangling fiber webs to obtain a nonwoven fabric, needle punching, water jet punching, or the like can be used.

As for the form of the nonwoven fabric, as mentioned above, either short fiber nonwoven fabric or long fiber nonwoven fabric can be used, but short fiber nonwoven fabric has more fibers oriented in the thickness direction of the artificial leather than long fiber nonwoven fabric. It is possible to obtain a highly dense feeling on the surface of artificial leather when brushed.

When producing a short fiber nonwoven fabric as a nonwoven fabric, the obtained microfiber-expressing fiber is preferably crimped and cut into a predetermined length to obtain raw cotton, which is then spread, laminated, and entangled. By doing this, a short fiber nonwoven fabric is obtained. A known method can be used for crimping and cutting.

Further, when the artificial leather includes a woven fabric, the obtained nonwoven fabric and woven fabric are laminated and entangled and integrated. To entangle and integrate the nonwoven fabric and the woven fabric, the woven fabric is laminated on one or both sides of the nonwoven fabric, or the woven fabric is sandwiched between multiple nonwoven fabric webs, and then the nonwoven fabric is separated by a needle punching process, a water jet punching process, etc. It can entangle the fibers of textiles.

It is preferable that the apparent density of the nonwoven fabric made of ultrafine fiber-expressing fibers after needle punching or water jet punching is 0.15 g/cm ³ or more and 0.45 g/cm ³ or less. By setting the apparent density to preferably 0.15 g/cm ³ or more, the artificial leather can have sufficient morphological stability and dimensional stability. On the other hand, by setting the apparent density to preferably 0.45 g/cm ³ or less, sufficient space for providing the polymer elastic body can be maintained.

In a preferred embodiment, the nonwoven fabric is subjected to heat shrinkage treatment using hot water or steam in order to improve the denseness of the fibers.

Next, the nonwoven fabric can be impregnated with an aqueous solution of the water-soluble resin and dried to impart the water-soluble resin. By adding a water-soluble resin to the nonwoven fabric, fibers are fixed and dimensional stability is improved.

<Process of developing ultrafine fibers>
In this step, the obtained fibrous base material is treated with a solvent to develop ultrafine fibers having an average single fiber diameter of 1.0 μm or more and 10.0 μm or less.

The ultrafine fiber development treatment can be carried out by immersing a nonwoven fabric made of sea-island composite fibers in a solvent and dissolving and removing the sea portions of the sea-island composite fibers.

When the ultrafine fiber-expressing fiber is a sea-island composite fiber, an organic solvent such as toluene or trichloroethylene can be used as the solvent for dissolving and removing the sea portion when the sea portion is polyethylene, polypropylene, or polystyrene. Moreover, when the sea part is copolymerized polyester or polylactic acid, an alkaline aqueous solution such as sodium hydroxide can be used. Moreover, when the sea part is a water-soluble thermoplastic polyvinyl alcohol resin, hot water can be used.

<Process of imparting polymer elastic body>
In this step, a polymer elastic body is applied to the fibrous base material. That is, a fibrous base material mainly composed of ultrafine fibers is impregnated with a solution of an elastic polymer and solidified to provide an elastic polymer. Methods for fixing an elastic polymer to a nonwoven fabric include a method of impregnating a solution of the elastic polymer into a nonwoven fabric (fiber entangled body) and then wet coagulation or dry coagulation. These methods can be selected as appropriate.

As the solvent used when applying polyurethane as the polymeric elastomer, N,N'-dimethylformamide, dimethyl sulfoxide, etc. are preferably used. Alternatively, a water-dispersed polyurethane liquid in which polyurethane is dispersed in water as an emulsion may be used.

The polymer elastic material may be applied to the fibrous base material before generating ultrafine fibers from ultrafine fiber generation type fibers, or after generating ultrafine fibers from ultrafine fiber generation type fibers. It's okay.

<Step of cutting in half and polishing>
From the viewpoint of manufacturing efficiency, it is also a preferable embodiment to cut the fibrous base material to which the polymeric elastic body has been applied after the above process is cut in half in the thickness direction to form two fibrous base materials.

Furthermore, the surface of the fibrous base material provided with the above-mentioned elastic polymer material or the fibrous base material provided with the elastic polymer material cut in half can be subjected to a napping treatment. The raising treatment can be performed by grinding using sandpaper, a roll sander, or the like. The raising treatment can be applied to only one surface of the artificial leather, or can be applied to both sides.

In the case of performing a napping treatment, a lubricant such as a silicone emulsion can be applied to the surface of the artificial leather before the napping treatment. Furthermore, by applying an antistatic agent before the napping treatment, grinding dust generated from the artificial leather during grinding becomes difficult to accumulate on the sandpaper.

<Process of dyeing artificial leather>
Furthermore, it is also preferable to further dye the artificial leather obtained by the above method for producing artificial leather. In particular, it is more preferable to carry out dyeing treatment with a dye of the same color as the pigment. Examples of this dyeing process include jet dyeing using a jigger dyeing machine or jet dyeing machine, thermosol dyeing using a continuous dyeing machine, roller printing, screen printing, inkjet printing, and sublimation. Printing treatment on the raised surface by printing, vacuum sublimation printing, etc. can be used. Among these, it is preferable to use a jet dyeing machine from the viewpoint of quality and elegance, since a soft texture can be obtained. Moreover, various resin finishing processes can be applied after dyeing, if necessary.

<Post-processing process>
Moreover, the surface of the above-mentioned artificial leather can be provided with a design if necessary. For example, post-processing treatments such as perforation, embossing, laser processing, pinsonic processing, and printing can be performed.

The artificial leather of the present invention obtained by the manufacturing method exemplified above has a soft texture similar to natural leather and excellent durability, and can be used in a wide range of applications from furniture, chairs and vehicle interior materials to clothing. However, it is particularly suitable for use in vehicle interior materials due to its excellent light resistance and fastness.

Next, the artificial leather of the present invention will be explained in more detail using Examples, but the present invention is not limited to these Examples. Next, the evaluation method and measurement conditions used in the examples will be explained. However, in the measurement of each physical property, unless otherwise specified, the measurement was performed based on the method described above. In addition, hereinafter, the portions described as "Example 2", including those in Table 2, shall be read as "Reference Example 1".

[Measurement method and processing method for evaluation]
A. Area of thermoplastic resin region (B) containing chromatic fine particle oxide pigment (S _B ) and area of ultrafine fiber (S _F )
Ultrathin sections in the cross-sectional direction of the plane perpendicular to the longitudinal direction of the ultrafine fibers were prepared using an ultramicrotome "MT6000 model" manufactured by Sorvall. The obtained sections were observed using a transmission electron microscope ("H7700" manufactured by Hitachi High Technologies). Next, regarding the area of the ultrafine fiber (S _F ), the distance X from the surface to the chromatic fine particle oxide pigment, and the area (S _B ) of the thermoplastic resin region (B) containing the chromatic fine particle oxide pigment, Measurement was performed using image analysis software ("WinROOF" manufactured by Mitani Shoji).

B. Average Particle Size of Chromatic Fine Particle Oxide Pigment Ultrathin sections in the cross-sectional direction of the plane perpendicular to the longitudinal direction of the ultrafine fibers were prepared using an ultramicrotome "MT6000 model" manufactured by Sorvall. The obtained sections were observed using a transmission electron microscope ("H7700" manufactured by Hitachi High Technologies). Next, the particle diameter of the pigment was measured using image analysis software ("WinROOF" manufactured by Mitani Corporation).

C. Artificial leather hue (L ^* value, a ^* value, b ^* value)
L ^* value, a ^* specified in 3.3 and 3.4 of JIS Z8781-4:2013 "Colorimetry - Part 4: CIE1976L ^* a ^* b ^* color space" mentioned above using a spectrophotometric system The b ^* value was measured. The measurement was performed 10 times using "CR-310" manufactured by Konica Minolta, and the average was taken as the L ^* value, a ^* value, and b ^* value of the artificial leather.

D. Light fastness of artificial leather The degree of discoloration and fading of the sample after irradiation is graded using the gray scale for discoloration and fading specified in JIS L0804:2004 "Gray scale for discoloration and fading", and it is graded as No. 4 or higher (L ^* a ^* b ^* A color difference ΔE ^* _ab of 1.7±0.3 or less according to the color system was regarded as a pass.

E. Abrasion resistance of artificial leather James H. Heal & Co. "Model 406" manufactured by the company was subjected to an abrasion resistance test using the company's "Abrasive CLOTH SM25" as a standard friction cloth, and artificial leathers with an abrasion loss of 10 mg or less were passed.

[Manufacture of raw cotton]
<Manufacture of raw cotton A>
An ultrafine fiber-expressing fiber having an island-in-sea composite structure in which a core component and a sheath component are combined into a core-sheath type to form islands and a sea area was melt-spun under the following conditions.
・Sheath component: A mixture of the following components (a) and (b) at a mass ratio of 95:5 (a) Polyethylene terephthalate A with an intrinsic viscosity (IV value) of 0.73
(b) Red fine particle oxide pigment (“TM Red 8270” manufactured by Dainichiseika Chemical Co., Ltd., average primary particle diameter: 0.07 μm, pigment concentration: 20% by mass)
・Core component: Polyethylene terephthalate A mentioned above
・Ama: Polystyrene with MFR of 65 g/10 minutes ・Merch: 3-component sea-island type composite ferrule with 16 islands/holes ・Spinning temperature: 285°C
・Core component/sheath component mass ratio: 80/20
・Island/Ama mass ratio: 80/20
・Discharge amount: 1.2g/(minute/hole)
- Spinning speed: 1100m/min.

Next, it was stretched 2.7 times in a spinning oil solution bath at 90°C. After crimping using a push-type crimper, the fiber was cut into a length of 51 mm to obtain sea-island composite fiber raw cotton A having a single fiber fineness of 3.8 dtex. The obtained raw cotton A is shown in Table 1.

<Manufacture of raw cotton B>
The single fiber fineness was determined in the same manner as in the production of raw cotton A, except that a red fine particle oxide pigment (average primary particle diameter: 0.3 μm, pigment concentration: 20% by mass) was used as the chromatic fine particle oxide pigment. Raw cotton B, which is an island-in-the-sea composite fiber, having a dtex of 3.8 dtex was obtained. The obtained raw cotton B is shown in Table 1.

<Manufacture of raw cotton C>
Instead of the chromatic fine particle oxide pigment, a carbon black masterbatch (average primary particle size: 0.05 μm, pigment concentration: 20% by mass) was used, and the mass ratio of components (a) and (b) was 99. Raw cotton C, which is a sea-island composite fiber with a single fiber fineness of 3.8 dtex, was obtained in the same manner as in the production of raw cotton A, except that: 1 was used. The obtained raw cotton C is shown in Table 1.

<Manufacture of raw cotton D>
Ultrafine fiber-expressing fibers having a sea-island composite structure consisting of islands and seas were melt-spun under the following conditions.
・ Island part: A mixture of the following components (a) and (b) at a mass ratio of 95:5 (a) Polyethylene terephthalate A with an intrinsic viscosity (IV value) of 0.73
(b) Red fine particle oxide pigment (“TM Red 8270” manufactured by Dainichiseika Chemical Co., Ltd., average primary particle diameter: 0.07 μm, pigment concentration: 20% by mass)
・Ama: Polystyrene with MFR of 65 g/10 minutes ・Merch: Sea-island type composite ferrule with 16 islands/holes ・Spinning temperature: 285°C
・Island/Ama mass ratio: 80/20
・Discharge amount: 1.2g/(minute/hole)
- Spinning speed: 1100m/min.

Next, it was stretched 2.7 times in a spinning oil solution bath at 90°C. After crimping using a push-in type crimper, it was cut into a length of 51 mm to obtain a sea-island composite fiber raw cotton D having a single fiber fineness of 3.8 dtex.

<Manufacture of raw cotton E>
Raw cotton F, which is a sea-island type composite fiber having a single fiber fineness of 3.8 dtex, was obtained in the same manner as in the production of raw cotton D, except that the island portion was 100% by mass of component (a). The obtained raw cotton F is shown in Table 1.

[Example 1]
<Process of manufacturing fibrous base material>
First, a laminated web was formed using raw cotton A through a carding and cross-wrapping process. Then, needle punching was performed using a punch count of 2500 punches/cm ² to obtain a nonwoven fabric having a basis weight of 550 g/m ² and a thickness of 2.5 mm.

<Process of developing ultrafine fibers>
The nonwoven fabric obtained as described above was subjected to a shrinkage treatment with hot water at 96°C. Thereafter, a polyvinyl alcohol (PVA) aqueous solution with a degree of saponification of 88%, which was prepared to have a concentration of 12% by mass, was impregnated into a nonwoven fabric that had been subjected to a contraction treatment with hot water. Further, this was squeezed with a roll and dried with hot air at a temperature of 120°C for 10 minutes while migrating the PVA, to obtain a PVA-coated sheet in which the mass of PVA was 25% by mass based on the mass of the sheet base. The PVA-coated sheet thus obtained was immersed in trichlorethylene, and squeezed and compressed using a mangle 10 times. As a result, the sea portion was dissolved and removed, and the PVA-coated sheet was subjected to compression treatment, thereby obtaining a PVA-coated sheet in which ultrafine fiber bundles to which PVA was applied were entangled.

<Process of imparting polymer elastic body>
The PVA-coated sheet obtained as described above was immersed in a polyurethane DMF (dimethylformamide) solution prepared so that the solid content containing polyurethane as the main component was 13%. Thereafter, the sea-removed PVA-attached sheet soaked in the polyurethane DMF solution was squeezed with a roll. Next, this sheet was immersed in a DMF aqueous solution having a concentration of 30% by mass to coagulate the polyurethane. Thereafter, PVA and DMF were removed with hot water and dried with hot air at a temperature of 110° C. for 10 minutes. As a result, a polyurethane-coated sheet having a thickness of 1.8 mm and having a polyurethane mass of 30% by mass relative to the mass of the fibrous base material was obtained.

<Half-cutting and brushing process>
The polyurethane-coated sheet obtained as described above was cut in half so that each half had a thickness of 1/2. Next, the surface layer on the opposite side of the half-cut surface was ground by 0.3 mm using endless sandpaper with a sandpaper count of 180, and the surface layer was brushed so that the nap length on the surface was 300 μm. A napped sheet was obtained.

<Dyeing and finishing process>
The raised sheet obtained as described above was dyed with a red dye using a jet dyeing machine. Thereafter, a drying treatment was performed at 100° C. for 7 minutes to obtain artificial leather having an average single fiber diameter of ultrafine fibers of 4.4 μm, a basis weight of 230 g/m ² , and a thickness of 0.7 mm. The obtained artificial leather had excellent light fastness, abrasion resistance, and high strength. Moreover, the color difference change before and after de-dying was also small. The results are shown in Table 2.

[Example 2]
<Process of manufacturing fibrous base material ~ Cutting in half and raising process>
A raised sheet having a thickness of 0.6 mm was obtained in the same manner as in Example 1 except that raw cotton D was used.

<Dyeing and finishing process>
The raised sheet obtained as described above was dyed using a jet dyeing machine using a red dye so as to have the same color as the artificial leather of Example 1. Thereafter, a drying treatment was performed at 100° C. for 7 minutes to obtain artificial leather having an average single fiber diameter of ultrafine fibers of 4.4 μm, a basis weight of 230 g/m ² , and a thickness of 0.7 mm. The obtained artificial leather had excellent light fastness, abrasion resistance, and high strength. Moreover, the color difference change before and after de-dying was also small. The results are shown in Table 2.

[Comparative example 1]
<Process of manufacturing fibrous base material ~ Cutting in half and raising process>
A raised sheet with a thickness of 0.6 mm was obtained in the same manner as in Example 1 except that raw cotton B was used.

<Dyeing and finishing process>
The raised sheet obtained as described above was dyed using a jet dyeing machine using a red dye so as to have the same color as the artificial leather of Example 1. Thereafter, a drying treatment was performed at 100° C. for 7 minutes to obtain artificial leather having an average single fiber diameter of ultrafine fibers of 4.4 μm, a basis weight of 230 g/m ² , and a thickness of 0.7 mm. Although the obtained artificial leather had excellent light fastness and a small change in color difference before and after dedying, it was inferior in abrasion resistance and strength. The results are shown in Table 2.

[Comparative example 2]
<Process of manufacturing fibrous base material ~ Cutting in half and raising process>
A napped sheet with a thickness of 0.6 mm was obtained in the same manner as in Example 1 except that raw cotton C was used.

<Dyeing and finishing process>
The raised sheet obtained as described above was dyed using a jet dyeing machine using a red dye so as to have the same color as the artificial leather of Example 1. Thereafter, a drying treatment was performed at 100° C. for 7 minutes to obtain artificial leather having an average single fiber diameter of ultrafine fibers of 4.4 μm, a basis weight of 230 g/m ² , and a thickness of 0.7 mm. Although the obtained artificial leather had excellent strength and abrasion resistance, it was inferior in light fastness, and the color difference before and after dedying was large. The results are shown in Table 2.

[Comparative example 3]
<Process of manufacturing fibrous base material ~ Cutting in half and raising process>
A raised sheet with a thickness of 0.6 mm was obtained in the same manner as in Example 1 except that raw cotton E was used.

<Dyeing and finishing process>
The raised sheet obtained as described above was dyed using a jet dyeing machine using a red dye so as to have the same color as the artificial leather of Example 1. Thereafter, a drying treatment was performed at 100° C. for 7 minutes to obtain artificial leather having an average single fiber diameter of ultrafine fibers of 4.4 μm, a basis weight of 230 g/m ² , and a thickness of 0.7 mm. Although the obtained artificial leather had excellent strength and abrasion resistance, it was inferior in light fastness, and the color difference before and after dedying was large. The results are shown in Table 2.

Claims (8)

Artificial leather consisting of a fiber entangled body consisting of ultrafine fibers with an average single fiber diameter of 1.0 μm or more and 10.0 μm or less, and a polymeric elastomer, wherein the ultrafine fibers have an average secondary particle diameter of 0.05 μm. It is made of a thermoplastic resin containing a chromatic fine particle oxide pigment with a size of 0.30 μm or less, and of the ultrafine fibers, the region (A) of the thermoplastic resin that does not contain the chromatic fine particle oxide pigment has the chromatic color. An artificial leather included in the region (B) of a thermoplastic resin containing a particulate oxide pigment . A claim in which the light fastness measured based on "a) 1st exposure method" in "7.2 Exposure method" of JIS L0843:2006 "Test method for color fastness to xenon arc lamp light" is grade 4 or higher. 1. The artificial leather according to 1. The artificial leather according to claim 1 or 2, which contains a dye and has a color difference (ΔE _ab ) of 15 or less before and after dedying. The artificial leather according to any one of claims 1 to 3, wherein the thermoplastic resin is made of a polyester resin. The artificial leather according to any one of claims 1 to 4, wherein the polymeric elastic body is made of polyurethane. The ratio (S _B /S _F ) of the area (S _B ) of the thermoplastic resin region (B) containing the chromatic fine particle oxide pigment to the area (S _F ) of the ultrafine fibers is 5% or more and 50% or less. The artificial leather according to any one of claims 1 to 5 . Expression of ultrafine fibers with a sea-island composite structure in which the island part is a thermoplastic resin containing a chromatic fine particle oxide pigment with an average primary particle diameter of 0.01 μm or more and 0.15 μm or less, and the sea part is an easily soluble polymer. After carrying out the step of producing shaped fibers, a fibrous base material made of ultrafine fibers is formed, and a polymer elastic body is further added to the fibrous base material to produce the artificial material according to any one of claims 1 to 6 . A method for producing artificial leather to obtain leather. A method for producing artificial leather, which further comprises dyeing the artificial leather according to any one of claims 1 to 6 , or the artificial leather obtained by the method for producing artificial leather according to claim 7 .