JP6346873B2 - Artificial leather - Google Patents

Description

  The present invention relates to an artificial leather having a texture and appearance close to those of natural leather.

  2. Description of the Related Art Conventionally, artificial leather that is similar to natural leather and has a colored surface layer formed on the surface of a fiber base material is known. Such artificial leather is widely used as an alternative to natural leather for shoes, clothing, gloves, bags, balls, interiors, vehicle interiors, and the like.

  Natural leather has a low resilience, a fine crease, and a high surface cushion. Such characteristics of natural leather are manifested by the formation of a surface layer of a dense tissue containing collagen fibers with few voids. The low resilience, for example, exhibits a property of retaining the shape of the rounded leather when the hand is opened and released after the natural leather is rounded, and a supple drape feeling. In addition, the natural leather has a rounded delicate crease when it is bent. Further, when the surface is pressed with a finger, it has a cushioning property that recovers to its original shape over time while being low in resilience.

  On the other hand, a conventionally known general artificial leather includes a fiber base material in which a nonwoven fabric is filled with a polymer elastic body. Such a fiber base material has voids that are not filled with a polymer elastic body, so that it is less dense and fuller than natural leather. For this reason, when folded, it is buckled and folded as if called “boiled”. Although the voids can be reduced by increasing the content of the polymer elastic body in the nonwoven fabric, in this case, the feeling of resilience is increased and the rubber-like and rigid texture becomes remarkable.

  As artificial leather brought closer to the characteristics of natural leather, for example, Patent Document 1 below includes a fiber entanglement, a filler, a polymer elastic body, and a liquid non-volatile oil impregnated in the fiber entanglement. An artificial leather substrate is disclosed. Such artificial leather has a high sense of fulfillment while having flexibility. However, even with such artificial leather, for example, when it is released by opening the hand after being gripped with a hand, it is quickly recovered from the shape when it is rounded by the repulsive force. Expresses supple characteristics. In addition, such artificial leather has poor surface cushioning because the sense of fullness of the fiber base material is too high. Moreover, smoothness and embossing were poor. From such a point, the artificial leather disclosed in Patent Document 1 is also sufficiently flexible and has a surface cushioning property while having a suppleness, and is sufficiently similar to natural leather in terms of smoothness. It was not done.

  By the way, natural leather has been widely used. For example, in applications such as skin materials for car seats of automobiles, further improvements in dye fastness and light resistance are required. For example, car seats equipped with seat heaters for warming seats are becoming popular. When natural leather dyed with a dye is used as the skin material of a car seat equipped with such a seat heater, the dye may sublimate due to the heat of the heater, or the dye may be altered and discolored. . Furthermore, for example, when aniline leather is to be applied to the skin material of a car seat, the aniline leather coating film has low durability and may be disadvantageous in that it easily causes discoloration and water spots. It was difficult.

WO2014 / 132630 pamphlet

  An object of the present invention is to provide an artificial leather having a fine crease feeling, a low rebound feeling, a high surface cushioning property and a smoothness, such as natural leather.

The artificial leather according to the present invention includes a fiber base material, a porous layer laminated on the fiber base material, and a skin layer laminated on the porous layer, and the fiber base material is a fiber entangled body 100 of ultrafine fibers. 3 to 30 parts by mass of filler, 5 to 12 parts by mass of polymer elastic body, and 2 to 20 parts by mass of liquid nonvolatile oil, and (filler + polymer elastic body) / liquid The non-volatile oil is a base material having a ratio of 1.5 to 10 and an apparent density of 0.55 g / cm ³ or more, and the porous layer has a thickness of 50 to 800 μm and an expansion coefficient of 1.5 to It is an artificial leather that is a 5 times elastic layer. The fiber base as described above contains a dense fiber entangled body, does not contain many polymer elastic bodies that increase the rebound feeling, and instead provides a sense of fulfillment with a filler and non-volatile oil. Such a fiber base material has a sense of fulfillment and flexibility. In addition, by arranging a porous layer having a thickness of 50 to 800 μm and an expansion coefficient of 1.5 to 5 times on a fiber base material that combines such a sense of fulfillment and flexibility, the surface is superior in terms of low resilience, An artificial leather excellent in cushioning and smoothness can be obtained.

  The fiber base material preferably contains a pigment having an average particle diameter of 0.5 μm or more. Such a pigment is preferable because it is easily fixed to the fiber entangled body and has an excellent balance between the hiding power and the coloring power.

  The skin layer is preferably formed of a light-transmitting film having a total light transmittance of 5% or more colored with a pigment having an average particle diameter of less than 0.5 μm. According to such a configuration, a translucent and deep color like an aniline leather is expressed. In addition, compared with dyed natural leather, since it is colored with a pigment, the colorant has excellent durability such as fastness and light resistance.

  The non-volatile oil preferably contains at least one selected from liquid paraffin, silicone oil, mineral oil, and phthalates.

  Moreover, it is preferable that a filler contains at least 1 type chosen from an inorganic filler and an organic filler.

  ADVANTAGE OF THE INVENTION According to this invention, the artificial leather provided with a fine crease feeling, a low repulsion feeling, high surface cushioning property, and smoothness like a natural leather is obtained.

FIG. 1 is a schematic cross-sectional view of an artificial leather 10 according to an embodiment of the present invention. FIG. 2 is an SEM photograph of a cross section of the artificial leather obtained in Example 1. FIG. 3 is a SEM photograph of the surface of the artificial leather obtained in Example 1. 4 is an SEM photograph of a cross section of the artificial leather obtained in Comparative Example 1. FIG. FIG. 5 is an SEM photograph of the surface of the artificial leather obtained in Comparative Example 1. 6 is an SEM photograph of a cross section of the artificial leather obtained in Comparative Example 2. FIG.

FIG. 1 is a schematic cross-sectional view of an artificial leather 10 according to an embodiment of the present invention. The artificial leather 10 includes a fiber base material 1 including a fiber entangled body 1 a, a porous layer 2 formed on the surface of the fiber base material 1, and a skin layer 3. The fiber base 1 is composed of 3 to 30 parts by weight of the filler 4, 5 to 12 parts by weight of the polymer elastic body 5, and 2 to 2 parts of the liquid non-volatile oil 6 with respect to 100 parts by weight of the fiber entangled body of ultrafine fibers. 20 parts by mass and a high density fiber having a ratio of (filler + polymer elastic body) / liquid non-volatile oil = 1.5 to 10 and having an apparent density of 0.55 g / cm ³ or more It is a substrate. The porous layer 2 is an elastic layer having an expansion coefficient of 1.5 to 5 times and a thickness of 50 to 800 μm.

  Hereinafter, the artificial leather of the present embodiment will be described in detail along with an example of a manufacturing method thereof.

  The fiber substrate includes a fiber entanglement of ultrafine fibers. The fiber entangled body of ultrafine fibers can be obtained, for example, by entanglement processing of ultrafine fiber generating fibers such as sea-island type composite fibers to form a fiber entangled body, and then subject the fibers to ultrafine fiber treatment. In the present embodiment, the case where the sea-island type composite fiber is used will be described in detail. However, even if an ultrafine fiber-generating fiber other than the sea-island type composite fiber is used, it is directly used without using the ultrafine fiber-generating fiber. Ultra fine fibers may be spun. In addition, as a specific example of the ultrafine fiber generation type fiber other than the sea-island type composite fiber, a plurality of ultrafine fibers are formed by lightly bonding immediately after spinning, and a plurality of ultrafine fibers are formed by unraveling by mechanical operation. Such as a split-divided fiber, or a petal-type fiber in which a plurality of resins are alternately gathered in a petal shape in the melt spinning process, and any fiber that can form ultrafine fibers is used without particular limitation. It is done.

  In the production of the ultrafine fiber entangled body, first, the thermoplastic resin constituting the sea component of the sea-island type composite fiber that can be selectively removed and the island component of the sea-island type composite fiber that is the resin component forming the ultrafine fiber are constituted. A sea-island type composite fiber is obtained by melt spinning and stretching a thermoplastic resin.

  As the sea component thermoplastic resin, a thermoplastic resin having a different solubility in a solvent or a decomposability in a decomposing agent is selected from the island component resin. Specific examples of the thermoplastic resin constituting the sea component include, for example, a water-soluble polyvinyl alcohol resin, polyethylene, polypropylene, polystyrene, ethylene propylene resin, ethylene vinyl acetate resin, styrene ethylene resin, styrene acrylic resin, and the like. .

  The thermoplastic resin, which is a resin component that forms island components and forms ultrafine fibers, is not particularly limited as long as it is a resin that can form sea-island composite fibers and ultrafine fibers. Specifically, for example, polyethylene terephthalate (PET), isophthalic acid modified PET, sulfoisophthalic acid modified PET, polybutylene terephthalate, polyhexamethylene terephthalate and other aromatic polyesters; polylactic acid, polyethylene succinate, polybutylene succinate, Aliphatic polyesters such as polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate resin; polyamides such as polyamide 6, polyamide 66, polyamide 10, polyamide 11, polyamide 12, polyamide 6-12; polypropylene, polyethylene, polybutene , Polyolefins such as polymethylpentene and chlorinated polyolefin. These may be used alone or in combination of two or more.

  As a method for producing a fiber entangled body of ultrafine fibers, for example, a sea island type composite fiber is melt spun to produce a web, the web is entangled, and then sea components are selectively removed from the sea island type composite fiber. Examples thereof include a method for forming ultrafine fibers. As a method for producing a web, a long-fiber sea-island composite fiber spun by a spunbond method or the like is collected on a net without being cut to form a long-fiber web, or a long fiber is cut into staples. And a method of forming a short fiber web. Among these, a long fiber web is particularly preferable because it is excellent in denseness and fullness. In addition, the formed web may be subjected to a fusion treatment in order to impart shape stability.

  Usually, in any process from removing sea components of the web made of sea-island type composite fibers to forming ultrafine fibers, fiber shrinkage treatment such as entanglement treatment, heat shrinkage treatment with water vapor, etc. It is preferable to apply a crystallization treatment. As the entanglement treatment, for example, a method in which about 5 to 100 obtained webs are stacked and the web is entangled using a known nonwoven fabric manufacturing method such as needle punching or high-pressure water flow treatment is used.

  The sea component of the sea-island composite fiber can be removed by extraction or decomposition at an appropriate stage after the web is formed. By such decomposition removal or extraction removal, the sea-island type composite fibers are made into ultrafine fibers to form fiber bundles of ultrafine fibers.

  The fineness of the ultrafine fibers is preferably 0.001 to 0.9 dtex, more preferably 0.01 to 0.6 dtex, and particularly preferably 0.02 to 0.5 dtex. When the fineness is too high, the feeling of denseness becomes insufficient, and a fiber entangled body with a feeling of coarseness tends to be obtained. Further, fibers with too low fineness are difficult to produce, and the fibers tend to converge without being unraveled, and the resulting fiber entanglement tends to increase in rigidity.

  The fiber entangled body of the ultrafine fibers thus obtained is subjected to thickness adjustment and flattening treatment by slicing or buffing as necessary. In this way, a fiber entanglement of ultrafine fibers is obtained.

Although the thickness of a fiber entangled body is not specifically limited, It is preferable that it is about 100-3000 micrometers, Furthermore, about 300-2000 micrometers. The apparent density of the fiber entangled body is not particularly limited, but is 0.25 to 0.70 g / cm ³ , further 0.45 to 0.65 g / cm ³ , particularly 0.55 to 0.60 g / cm ³ . ³ is preferably from the viewpoint of obtaining an artificial leather excellent in balance between fullness and flexibility.

  The fiber entangled body is impregnated with 3 to 30 parts by weight of filler, 5 to 12 parts by weight of polymer elastic body, and 2 to 20 parts by weight of liquid non-volatile oil with respect to 100 parts by weight of fiber entangled body of ultrafine fibers. Is granted. Fillers, polymer elastic bodies, and liquid non-volatile oils fill the gaps in the fiber entanglement to give a sense of fullness without losing flexibility, and apply a coating solution to the porous layer or skin layer. When forming by doing, it suppresses that a coating liquid osmose | permeates excessively to a fiber base material.

  In order to impregnate a fiber entangled body with a filler, a polymer elastic body, and a liquid non-volatile oil, for example, these components are homogeneously mixed in a dispersion medium such as water or a mixture of water and a polar solvent such as alcohol. Those mixed and dispersed in are used.

  After the fiber entangled body is impregnated with the dispersion liquid, the volatile component such as the dispersion medium is dried and removed to dry the filler, the polymer elastic body, and the liquid non-volatile oil between the fibers of the fiber entangled body. Remains. Although drying conditions are not specifically limited, For example, the conditions of making it dry for about 1 to 10 minutes at 70-150 degreeC are mentioned. The filler, the polymer elastic body, and the liquid non-volatile oil remain, for example, in a void in the form of clay or paste.

  Examples of the filler include an inorganic filler and an organic filler.

As the inorganic filler and the organic filler, for example, various fillers composed of metals, metal oxides, inorganic compounds, organic compounds and the like having an average particle diameter of 0.5 to 15 μm and further about 1 to 10 μm are used. Specific examples thereof include fillers of metal oxides such as alumina (Al ₂ O ₃ ), titanium dioxide (TiO ₂ ), zinc oxide (ZnO), cerium dioxide (CeO ₂ ); silica (SiO ₂ ), talc, mica , Fillers of inorganic compounds such as caged polysilsesquioxane (POSS); flame retardant fillers such as ammonium polyphosphate, aluminum dialkylphosphinate, and melamine phosphate; carbon nanotubes (CNT), carbon fibers (CF) Carbon black fillers such as carbon black (CB), graphite (GF), and acetylene black (AB). These may be used alone or in combination of two or more. In these, various flame-retardant fillers are especially preferable from the point which can provide a flame retardance simultaneously.

  Specific examples of the polymer elastic body include, for example, polyurethane, acrylic elastic body, silicone elastic body, diene elastic body, nitrile elastic body, fluorine elastic body, polystyrene elastic body, and polyolefin elastic body. And polyamide-based elastic bodies and halogen-based elastic bodies. These may be used alone or in combination of two or more. Among these, polyurethane is preferable from the viewpoint of excellent wear resistance and mechanical properties.

  As polyurethane, water-based polyurethanes such as polycarbonate-based polyurethane, polyester-based polyurethane, polyether-based polyurethane, and polycarbonate / ether-based polyurethane prepared in an emulsion are easy to prepare a dispersion and form a crosslinked structure. By making it exist in a space | gap without making it closely_contact | adhere too much to a fiber, it is especially preferable from the point which expresses a softer texture.

  The liquid non-volatile oil is a liquid having a boiling point of 150 ° C. or higher and substantially not dissolved in a polar solvent. Specifically, for example, liquid paraffin, mineral oil, silicone oil, phthalates, etc. Is mentioned. These may be used alone or in combination of two or more. Among these, liquid paraffin is particularly preferable because it has excellent chemical stability and is not easily oxidized.

  The quantity of the filler with respect to 100 mass parts of fiber entangled bodies is 3-30 mass parts, and it is preferable that it is 5-20 mass parts. When the amount of the filler relative to 100 parts by mass of the fiber entangled body is less than 3 parts by mass, the sense of fulfillment is lowered, and when it exceeds 30 parts by mass, the flexibility is lowered.

  Moreover, it is preferable that the quantity of the polymeric elastic body with respect to 100 mass parts of fiber entangled bodies is 5-12 mass parts, Furthermore, 6-10 mass parts. When the amount of the polymer elastic body with respect to 100 parts by mass of the fiber entangled body exceeds 12 parts by mass, the resilience is increased and the rubber feeling is increased, thereby reducing the flexibility. When the amount is less than 5 parts by mass, the cushioning properties are lowered, and when folded, creases remain and the quality is lowered.

  Moreover, the quantity of the non-volatile oil with respect to 100 mass parts of fiber entangled bodies is 2-20 mass parts, and it is preferable that it is 3-8 mass parts. When the amount of the non-volatile oil with respect to 100 parts by mass of the fiber entangled body is less than 2 parts by mass, the flexibility becomes difficult to obtain sufficiently, and when it exceeds 20 parts by mass, the fiber entangled body can hold the non-volatile oil. Easier to drop out.

  The ratio of (filler + polymer elastic body) / liquid nonvolatile oil is 1.5 to 10, preferably 2 to 8, particularly 3 to 7. When the ratio exceeds 10, the flexibility is lowered, and when it is less than 1.5, the sense of fulfillment is lowered.

  The fiber base material including the fiber entangled body preferably contains a pigment. The pigment may be fixed to the fiber entangled body with a polymer elastic body serving as a binder, or may be kneaded with the fiber itself forming the fiber entangled body, but it should be fixed to the fiber entangled body with a polymer elastic body. Is preferable from the viewpoint of easy coloring and color matching.

  The kind of pigment is not particularly limited. Specific examples thereof include organic pigments such as diketopyrrolopyrrole pigments, quinacridone pigments, anthraquinone pigments, and inorganic pigments such as iron oxide; Organic pigments such as pigments, quinophthalone pigments, condensed azo pigments and azo complex pigments, inorganic pigments such as bismuth yellow and titanium yellow; copper to phthalocyanine pigments, cobalt blue, bitumen, ultra Inorganic pigments such as marine; examples of the black type include carbon black. Such pigments may be used singly or in combination of two or more in order to adjust the target color.

  The average particle diameter of the pigment contained in the fiber entangled body is not particularly limited, but is 0.5 μm or more, further 0.6 μm or more, preferably 200 μm or less, and more preferably 150 μm or less. When the average particle diameter of the pigment is too small, the colorability tends to be reduced by embedding the polymer entangled body with the polymer elastic body when it is fixed to the fiber entangled body with the polymer elastic body. In addition, when the average particle diameter of the pigment is too large, when a dense fiber entangled body of ultrafine fibers is used, it becomes difficult to enter the void formed by the fiber entangled body and become difficult to be fixed. There is a tendency that the colorability of the part is lowered.

  The average particle diameter of the pigment means the average particle diameter of an aggregated pigment formed by fixing primary particles with a vehicle. The average particle diameter of such a pigment represents the dispersed particle diameter of the pigment particles. When a dispersion is used, the median obtained by measuring the dispersion as a raw material with a dynamic light scattering particle size distribution analyzer. It is substantially the same as the diameter.

  Thus, the fiber base containing 3 to 30 parts by mass of filler, 5 to 12 parts by mass of polymer elastic body, and 2 to 20 parts by mass of liquid non-volatile oil with respect to 100 parts by mass of the fiber entangled body of ultrafine fibers. A material is obtained. The fiber substrate is subjected to thickness adjustment and flattening treatment by slicing or buffing treatment as necessary, stagnation softening treatment, blanking softening treatment, reverse seal brushing treatment, antifouling treatment, hydrophilic treatment, Finishing treatment such as lubricant treatment, softener treatment, antioxidant treatment, ultraviolet absorber treatment, fluorescent agent treatment, flame retardant treatment, etc. may be applied.

The apparent density of the fiber substrate is 0.55 to 0.85 g / cm ³ , and preferably 0.6 to 0.75 g / cm ³ . When the apparent density of the fiber base material is less than 0.55 g / cm ^{3, the} sense of fulfillment decreases. Moreover, when too high, there exists a tendency for flexibility to fall. Moreover, it is preferable that the thickness of a fiber base material is about 100-3000 micrometers, Furthermore, about 300-2000 micrometers.

  And the porous layer which has a 50-800-micrometer-thick elasticity and the expansion coefficient of 1.5-5 times is formed in the surface of a fiber base material. Such a porous layer imparts low resilience to the resulting artificial leather and imparts high surface cushioning and smoothness.

  The porous layer is formed by applying a coating liquid, which is a liquid resin composition for forming a porous layer, directly on the surface of the fiber substrate using a roll coater or a spray coater, followed by drying or wet coagulation. It is formed. In addition, when trying to form a thick porous layer in the conventional fiber base material, a coating liquid permeate | transmitted too much into the fiber base material, and the surface layer became hard, and the flexibility was impaired. On the other hand, the fiber base as described above is dense, and the water repellency of the non-volatile oil prevents the coating liquid from penetrating excessively and easily forms a thick porous layer.

  Specific examples of the resin component for forming the porous layer include polyurethane, acrylic elastic body, silicone elastic body, diene elastic body, nitrile elastic body, fluorine elastic body, polystyrene elastic body, polyolefin base Examples include elastic bodies, polyamide-based elastic bodies, and halogen-based elastic bodies. These may be used alone or in combination of two or more. Among these, polyurethane is preferable from the viewpoint of excellent balance between wear resistance and mechanical properties. Also, the porous layer preferably contains the pigment as described above.

  The formation method of a porous layer is not specifically limited, The method of forming a porous layer by the dry foaming method, the mechanical foaming method, the wet coagulation foaming method etc. is mentioned. The dry foaming method is a method of forming a porous layer by blending a foaming agent or a microcapsule with a resin used for a dry-type surface and drying. The mechanical foaming method is a method in which a porous layer is formed by mechanically stirring a resin used for dry-type surface making a non-reactive gas such as air bitten. The wet coagulation method is a method of forming a porous layer by immersing and solidifying a polyurethane solution for forming a porous layer in a coagulation tank composed of a dimethylformamide (DMF) aqueous solution or water alone. Among these, the mechanical foaming method is preferable because the specific gravity of the polyurethane foam can be easily adjusted by adjusting the mixing amount of the non-reactive gas. Moreover, since the polyurethane foam which has a substantially spherical fine bubble can be continuously shape | molded, it is preferable from the point that manufacturing efficiency is good and the expansion coefficient of a porous layer is easy to control.

  In the mechanical foaming method, the non-reactive gas used to form fine bubbles is preferably a non-flammable gas. Specifically, nitrogen, oxygen, carbon dioxide gas, noble gases such as helium and argon, and these A mixed gas is exemplified, and the use of air that has been dried to remove moisture is most preferable in terms of cost. Moreover, in order to obtain the target polyurethane foam, it is preferable that the rotation speed of a stirring blade is 500-2000 rpm, More preferably, it is 500-1200 rpm. Moreover, although stirring time needs to be suitably adjusted according to the target specific gravity, it is about 2 to 5 minutes normally. In addition, stabilizers such as antioxidants, flame retardants, pigments, softeners, fillers, antistatic agents, moisture permeability improvers, and other additives may be added to the polyurethane foam as necessary. .

  The expansion rate of the porous layer is 1.5 to 5 times, and preferably 2 to 3 times. The expansion coefficient means a magnification indicating how many times the apparent volume of the porous layer is expanded with respect to the resin volume of the same mass excluding the pores. When the expansion rate of the porous layer is less than 1.5 times, the low rebound feeling and high surface cushioning properties are lowered, and when the expansion rate of the porous layer is more than 5 times, the fine creased feeling is lowered.

  Moreover, the thickness of a porous layer is 50-800 micrometers, and it is preferable that it is 200-600 micrometers. When the thickness of the porous layer is less than 50 μm, the smoothness, low resilience and high surface cushioning properties are lowered, and when it exceeds 800 μm, the resilience is increased.

  And the artificial leather of this embodiment is obtained by forming a skin layer in the porous layer formed on the surface of the fiber base material.

  The resin forming the skin layer is a resin component similar to the resin component used in the porous layer, and examples thereof include non-porous resins. The skin layer may be a single layer or a laminate of different types of layers. The method for forming the skin layer on the surface of the porous layer is not particularly limited. For example, a method of forming a film by applying a paint containing a resin component for forming a skin layer on the surface of the porous layer to form a coating film, and drying or wet coagulating the coating film to form a film. It is done. The method for applying the paint is not particularly limited, and means such as spray coating, roll coating, knife coating (comma coater) and the like can be used without particular limitation. In the process of forming the skin layer, which is a finishing process, the color can be adjusted by a simple painting process such as spray coating, so that the production efficiency is particularly excellent.

  The thickness of the skin layer is preferably 5 to 200 μm, more preferably 10 to 100 μm.

  The skin layer is preferably colored or dyed with a so-called transparent pigment having an average particle size of less than 0.5 μm. In particular, it is preferable that the pigment is colored with a transparent pigment from the viewpoint that a transparent feeling and a deep color can be felt like a dye-finished aniline leather. When colored with a transparent pigment having an average particle size of less than 0.5 μm, the skin layer can be colored while maintaining its transparency.

  The average particle diameter of the transparent pigment is preferably less than 0.5 μm, more preferably 0.4 μm or less, and particularly preferably 0.3 μm or less. When the average particle diameter of the transparent pigment is 0.5 μm or more, the light transmittance of the skin layer tends to decrease. The lower limit of the average particle diameter of the transparent pigment is not particularly limited, but is preferably about 0.1 μm from the viewpoint of colorability and productivity. Such a transparent pigment dispersion is commercially available, for example, from Nihongo Bix Corporation. The transparent pigments may be used alone or in combination of two or more in order to adjust the target color.

  Although the content rate of the pigment in a skin layer is not specifically limited, It is preferable that it is 0.1-10 mass%, Furthermore, it is preferable that it is 0.5-5 mass%. When the content ratio of the pigment in the skin layer is too high, the light transmittance tends to decrease, and when it is too low, the colorability tends to decrease.

  The skin layer preferably has a light transmittance of 5% or more, more preferably 20% or more, and particularly 30% or more. In such a case, when the artificial leather is exposed to light, part of the light passes through the skin layer, and the color of the fiber base material colored with the pigment is visually recognized. As a result, by allowing the person who visually recognizes the surface to visually recognize the color developed by coloring the fiber base material and the skin layer, the transparency and depth of the colour, such as dye-finished aniline leather, is achieved. You can feel it. The total light transmittance of the skin layer is, for example, a glass plate having a total light transmittance of 98% or more as a control, a film having the same thickness and the same composition as the skin layer is formed on the glass plate, and JIS-K7136 It can be measured by a method based on the prescribed total light transmittance (%) measurement method.

  The artificial leather thus obtained is further provided with a clear layer for protecting the surface, if necessary, itching softening treatment, blanking softening treatment, reverse seal brushing treatment, antifouling treatment, A finishing treatment such as a hydrophilic treatment, a lubricant treatment, a softener treatment, an antioxidant treatment, an ultraviolet absorber treatment, a fluorescent agent treatment, or a flame retardant treatment may be applied.

  Furthermore, a stamp pattern may be imparted to the surface of the artificial leather by embossing (such as embossing). In the artificial leather of this embodiment, since the porous layer is formed on the surface of the fiber substrate having a high degree of fullness, the porous layer is easily compressed and crushed when embossed. Therefore, the artificial leather of this embodiment is particularly excellent in the embossing property.

  The present invention will be described more specifically with reference to examples. The scope of the present invention is not limited by the examples. In the following description, “part” or “%” is based on mass unless otherwise specified.

[Example 1]
<Manufacture of entangled nonwoven fabric>
Water-soluble thermoplastic polyvinyl alcohol (PVA) as the sea component, isophthalic acid-modified polyethylene terephthalate having a modification degree of 6 mol% as the island component, and a uniform cross-sectional area in the sea component set at a base temperature of 260 ° C. Molten resin was supplied to a plurality of spinning nozzles in which nozzle holes forming a cross section in which 25 island components were distributed were arranged in parallel, and were discharged from the nozzle holes. At this time, it supplied, adjusting pressure so that the mass ratio of a sea component and an island component might become sea component / island component = 25/75.

Then, the discharged melted fiber was drawn by a suction device so that the average spinning speed was 3700 m / min, and a long fiber of a sea-island type composite fiber having a fineness of 2.1 dtex was spun. The spun long islands of sea-island type composite fibers were continuously deposited on a movable net, and lightly pressed with a metal roll at 42 ° C. to suppress surface fuzz. Then, the long fibers of the sea-island type composite fibers are peeled off from the net and passed between a lattice-patterned metal roll having a surface temperature of 55 ° C. and a back roll, so that they are hot-pressed at a linear pressure of 200 N / mm to have a basis weight of 31 g / mm An m ² long fiber web was obtained.

Next, the web was overlapped on 8 layers by using a cross wrapping apparatus so that the total basis weight was 250 g / m ² , a superposed web was prepared, and a needle breakage preventing oil was further sprayed. Next, using a 6 barb needle with a distance of 3.2 mm from the tip of the needle to the first barb, needle punching was alternately performed at 3300 punch / cm ² from both sides at a needle depth of 8.3 mm. The area shrinkage rate by the needle punching process was 68%, and the basis weight of the entangled web after the needle punching was 550 g / m ² .

The entangled web was immersed in hot water at 70 ° C. for 14 seconds at a winding line speed of 10 m / min to cause area shrinkage. Next, repeated dip nip treatment in 95 ° C. hot water is performed to dissolve and remove PVA, so that a fiber bundle having a fineness of 2.5 dtex containing 25 ultrafine fibers having a fineness of 0.1 dtex is three-dimensionally entangled. An intertwined nonwoven fabric was prepared. An area shrinkage measured after drying was 52%, a nonwoven fabric having a basis weight of 576 g / m ² and an apparent density of 0.565 g / cm ³ was obtained. Then, the nonwoven fabric was sliced and buffed to adjust the thickness to 1.05 mm, thereby obtaining a fiber entanglement of ultrafine fibers.

  On the other hand, by mixing an aqueous pigment dispersion containing a pigment having an average particle size of about 0.6 μm (particle size distribution: 0.5 to 20 μm) and an acrylic emulsion, 4.3 parts of pigment and 100 parts of fiber base material are mixed. A pigment impregnation dispersion for providing 2 parts of an acrylic elastomer was prepared. As the acrylic emulsion, R / W binder 5KS (manufactured by DIC Corporation) was used. Further, as the pigment, R / W Brown FFM (manufactured by DIC Corporation) 4% and R / W Black B (manufactured by DIC Corporation) 0.3% were blended to prepare a dark brown color. Then, the fiber entangled body was impregnated by dipping and niping the prepared dispersion liquid for impregnating the pigment so that the pickup rate was 60%, and dried to fix the pigment to the fiber entangled body.

  Thereafter, 2% polyurethane emulsion having a solid content of 30%, a dispersion of aluminum dialkylphosphinate having an average particle diameter of 5 μm with 38% owf (solid content of 40%), and liquid paraffin having a concentration of 15% owf (concentration of 30%) The layer was impregnated so as to have a pickup rate of 80% and dried. As the polyurethane emulsion, the soft segment is a 70:30 mixture of polyhexylene carbonate diol and polymethylpentanediol, and the hard segment is a crosslinked type polyurethane mainly composed of hydrogenated methylene diisocyanate (melting point: 180 to 190 ° C., An emulsion having a loss elastic modulus peak temperature of −15 ° C. and a hot water swelling ratio at 130 ° C. of 35% was used.

Then, the fiber entangled body is processed by using a shrinkage processing device (manufactured by Komatsubara Iron Works Co., Ltd., Sanforize machine) at a drum temperature of 120 ° C. of the contraction part, a drum temperature of 120 ° C. of the heat setting part and a conveyance speed of 10 m / min. The fiber base material was obtained by shrinking 5.5% in the vertical direction (length direction). The obtained fiber base material contains 13 parts of filler, 10 parts of polymer elastic body, and 4 parts of liquid non-volatile oil with respect to 100 parts of fiber entangled body, and (filler + polymer elasticity). Body) / liquid non-volatile oil = 5.8. The fiber substrate had a basis weight of 709 g / m ² and an apparent density of 0.645 g / cm ³ .

A coating liquid for forming a porous layer is roll-coated on the surface of the obtained fiber base at a coating amount of 300 g / m ² using a reverse coater, and heat-treated to increase the thickness to 280 μm and the expansion rate to 3 times. A porous layer was formed. In addition, as a coating liquid for forming a porous layer, 400 parts of polyurethane solutions (Permutex EVO RC-2102 solid content made from STAHL Co., Ltd.) and an average particle diameter of about 0.6 micrometer (particle size distribution 0. 0). 5 to 20 μm) of a pigment dispersion (solid content 25%) 100 parts and 3 parts of a crosslinking agent (STAR Co., Ltd. XR-22-419) were mixed, and the specific gravity was set to 0. 0 by a mechanical foaming machine (HANSA MIXER). A foam coating solution adjusted to 500 g / cm ³ was used.

Then, in order to form a non-porous color coat layer having a film thickness of 30 μm as a part of the skin layer, the color coat solution was sprayed with STARPLUS made by Gemata so that the coating amount was 140 g / m ² . As the color coating liquid, a pigment aqueous dispersion liquid (NSP-WG series, manufactured by Nihongo Bix Co., Ltd.) containing a transparent pigment having an average particle diameter of 0.2 μm (particle size distribution: 0.1 to 0.5 μm), solid About 20%) 50 parts and polyurethane resin (DIC Co., Ltd. LCC binder UB1770 solid content 30%) 400 parts are mixed, and thickener is 30 cp with Iwata Cup (IWATA NK-2 12s). What was adjusted in was used.

  The content ratio of the pigment in the color coat layer was 2.2%. Further, a glass plate having a total light transmittance of 98% or more is used as a control, and a film having the same thickness and the same composition as the color coat layer is formed on the glass plate, and the total light transmittance (%) defined in JIS-K7136. The total light transmittance of the color coat layer measured by a method based on the measurement method was 45%.

Further, the blanking process was performed at 40 to 50 ° C. for 2 to 4 hours. Then, the surface layer was embossed using an embossing roll at 125 ° C. and 50 kg / cm ² at a line speed of 7.0 m / min. Then, the top coat paint (star clear clear paint) adjusted to 30 cp with Iwata Cup (IWATA NK-2 12s) is applied to the surface to form a 15 μm thick top coat as part of the skin layer. Thus, an artificial leather having a basis weight of 740 g / m ² and an apparent density of 0.704 g / cm ³ was obtained. A scanning microscope (SEM) photograph of 50 times the cross section of the artificial leather thus obtained is shown in FIG. Moreover, the SEM photograph of 50 times the surface is shown in FIG.

<Evaluation of artificial leather>
The obtained artificial leather was evaluated according to the following evaluation methods.

(Low resilience)
The obtained artificial leather was cut to 20 × 20 cm to prepare a sample. And after grasping by hand so that artificial leather might be rounded, the state when opening and releasing the hand was judged as follows.
A: The shape when rounded was retained like natural leather.
B: The rounded shape was retained for a while and then gradually recovered to the original shape.
C: The shape immediately after being rounded by the repulsive force recovered to the original shape.

(Folding feeling)
The obtained artificial leather was cut to 20 × 20 cm to prepare a sample. And the external appearance was judged on the following references | standards, such as bending inside by making a center part a boundary.
A: Folding wrinkles with a feeling of solidity such as dense and fine creases and roundness occurred when folded. It was also excellent in drape.
B: Folding wrinkles were rough and deep wrinkles with a large buckling, and a fine feeling of bending wrinkles was not obtained. Moreover, it was inferior to the drape property.
C: The sense of fulfillment was remarkably low.

(Surface cushioning)
The obtained artificial leather was cut to 20 × 20 cm to prepare a sample. And the external appearance of the center part folded inward with the center part as a boundary was determined on the following reference | standard.
A: There was no stickiness at the corner that was folded in four, and there was a roundness.
B: There was no stickiness at the corner folded in four, but there was no roundness.
C: There was stickiness at the corner folded in four.

(Smoothness)
The surface of the artificial leather was observed with an SEM and determined as follows.
A: The skin layer was hardly submerged, and a smooth and smooth surface was formed.
B: There was a slight sinking of the epidermis layer, and a slight roughness of the surface fibers was felt.
C: The skin layer was almost submerged, and the surface was exposed with fibers and was fuzzy.

(Embossing)
A: The embossed shape was maintained as it was even after the embossed material was processed for 4 hours by blanking.
B: The embossed shape was retained after 2 hours of blanking, but could not be retained after 4 hours of treatment.
C: The stamped shape could not be maintained after the stamped one was processed for 2 hours by blanking.

(Surface color)
A: It was a transparent and deep color like a dye-finished aniline leather.
B: It was a slightly deep color with no translucency like pigmented leather.
C: It was a color with no transparency and a low-class feeling.

  The above evaluation results are shown in Table 1 below.

[Example 2]
In the formation of the porous layer of Example 1, instead of forming a porous layer having a thickness of 280 μm by roll-coating the coating liquid for forming the porous layer on the surface of the fiber substrate at a coating amount of 300 g / m ^2. In addition, a porous layer was formed in the same manner except that it was roll-coated at a coating amount of about 500 g / m ² to form a porous layer having a thickness of 460 μm and an expansion rate of 3 times. Artificial leather was obtained and evaluated. The results are shown in Table 1.

[Example 3]
In the formation of the porous layer of Example 1, instead of forming a porous layer having a thickness of 280 μm by roll-coating the coating liquid for forming the porous layer on the surface of the fiber substrate at a coating amount of 300 g / m ^2. In addition, a porous layer was formed in the same manner except that a porous layer having a thickness of 200 μm and an expansion rate of 3 times was formed by roll coating at an application amount of about 220 g / m ^2. Artificial leather was obtained and evaluated. The results are shown in Table 1.

[Example 4]
In the formation of the porous layer of Example 1, as a foam coating liquid for forming a porous layer, instead adjusted to a specific gravity of 0.500 g / cm ^3, except for adjusting the specific gravity of 0.300 g / cm ³ in the same manner The foam coating liquid for forming the prepared porous layer was used. Then, the prepared foam coating solution was roll-coated at a coating amount of about 300 g / m ² to form a porous layer having a thickness of 280 μm and an expansion rate of 5 times. Leather was obtained and evaluated. The results are shown in Table 1.

[Example 5]
In the formation of the porous layer of Example 1, as a coating liquid for forming a porous layer, instead adjusted to a specific gravity of 0.500 g / cm ^3, except for adjusting the specific gravity of 0.750 g / cm ³ in the same manner prepare The foam coating solution prepared was used. A porous layer was formed in the same manner except that the prepared foam coating solution was roll-coated at a coating amount of about 300 g / m ² to form a porous layer having a thickness of 280 μm and a double expansion rate. Through the same process as No. 1, artificial leather was obtained and evaluated. The results are shown in Table 1.

[Examples 6 to 9]
In Example 1, instead of impregnating 100 parts of fiber entangled body with 13 parts of filler, 10 parts of polymer elastic body, and 4 parts of liquid non-volatile oil, filler for 100 parts of fiber entangled body, polymer elasticity Artificial leather was obtained and evaluated in the same manner except that the ratio of the body and liquid non-volatile oil was changed as shown in Table 1. The results are shown in Table 1.

[Example 10]
In Example 1, a pigment dispersion having an average particle size of about 0.6 μm (particle size distribution: 0.5 to 20 μm) was used as the pigment dispersion mixed in the color coating solution, as in Example 1. Through the process, artificial leather was obtained and evaluated. The results are shown in Table 1.

[Comparative Example 1]
In the formation of the porous layer of Example 1, as a foam coating liquid for forming a porous layer, instead adjusted to a specific gravity of 0.500 g / cm ^3, except for adjusting the specific gravity of 0.980 g / cm ³ in the same manner A coating solution was prepared. Then, instead of forming a porous layer having a thickness of 280 μm by roll coating the surface of the fiber base material with a coating amount of 300 g / m ² , the coating solution is roll coated with a coating amount of about 120 g / m ^2. Artificial leather was obtained and evaluated in the same manner as in Example 1 except that a non-porous layer having a thickness of 100 μm was formed. The results are shown in Table 1. Further, FIG. 3 shows a scanning microscope (SEM) photograph of 50 times the cross section of the artificial leather thus obtained, and FIG. 4 shows a SEM photograph of 50 times the surface of the artificial leather.

[Comparative Example 2]
In the formation of the porous layer of Example 1, instead of forming a porous layer having a thickness of 280 μm by roll-coating the coating liquid for forming the porous layer on the surface of the fiber substrate at a coating amount of 300 g / m ^2. In addition, a wet layer is formed in the same manner except that a porous layer having a thickness of 280 μm and an expansion rate of 6 times is formed by a wet coagulation foaming method, and through the same steps as in Example 1, an artificial leather is obtained. evaluated. The results are shown in Table 1. Moreover, the scanning microscope (SEM) photograph of 50 times the cross section of the artificial leather thus obtained is shown in FIG.

[Comparative Example 3]
In Example 1, instead of impregnating 100 parts of fiber entangled body with 13 parts of filler, 10 parts of polymer elastic body, and 4 parts of liquid non-volatile oil, the fiber entangled body is 12.5 in solids. Artificial leather was obtained and evaluated in the same manner except that it was impregnated with the same aqueous polyurethane dispersion as used in Example 1 and dried at 120 ° C. The results are shown in Table 1.

[Comparative Example 4]
In Example 1, instead of impregnating 100 parts of fiber entangled body with 13 parts of filler, 10 parts of polymer elastic body, and 4 parts of liquid non-volatile oil, filler for 100 parts of fiber entangled body, polymer elasticity Artificial leather was obtained and evaluated in the same manner except that the ratio of the body and liquid non-volatile oil was changed as shown in Table 1. The results are shown in Table 1.

  From the results in Table 1, all the artificial leather obtained in Examples 1 to 10 according to the present invention has a fine crease feeling, low resilience, high surface cushioning and smoothness like natural leather. It was. On the other hand, the artificial leather of Comparative Example 1 in which a nonporous layer was formed instead of the porous layer was poor in fine crease feeling, low resilience, high surface cushioning and smoothness. Further, for example, comparing FIG. 3 and FIG. 5, the surface of the artificial leather of Example 1 according to the present invention is significantly smoother than the surface of the artificial leather of Comparative Example 1 in which a nonporous layer is formed. It turns out that it is excellent in property. Also, comparing FIG. 2 with FIG. 6, the porous layer of the artificial leather of Example 1 according to the present invention has voids formed more homogeneously than the porous layer of the artificial leather of Comparative Example 2. I understand that.

  The artificial leather of the present invention is used as a substitute material for natural leather for shoes, clothing, gloves, bags, balls, interiors, vehicles and the like.

DESCRIPTION OF SYMBOLS 1 Fiber base material 1a Fiber entanglement body 2 Porous layer 3 Skin layer 4 Polymer elastic body 5 Porous layer 6 Liquid non-volatile oil 10 Artificial leather

Claims (5)

A fiber substrate, a porous layer laminated on the fiber substrate, and a skin layer laminated on the porous layer,
The fiber base material is 3 to 30 parts by mass of filler, 5 to 12 parts by mass of polymer elastic body, and 2 to 20 parts by mass of liquid non-volatile oil with respect to 100 parts by mass of the fiber entangled body of ultrafine fibers. And it is a substrate having an apparent density of 0.55 g / cm ³ or more, which is contained at a ratio of (the filler + the polymer elastic body) / the liquid non-volatile oil = 1.5-10,
The artificial leather according to claim 1, wherein the porous layer is an elastic layer having a thickness of 50 to 800 µm and an expansion coefficient of 1.5 to 5 times. The artificial leather according to claim 1, wherein the fiber base material contains a pigment having an average particle diameter of 0.5 µm or more.   3. The artificial leather according to claim 1, wherein the skin layer is formed of a light-transmitting film having a total light transmittance of 5% or more colored with a pigment having an average particle diameter of less than 0.5 μm.   The artificial leather according to any one of claims 1 to 3, wherein the non-volatile oil includes at least one selected from liquid paraffin, silicone oil, mineral oil, and phthalates. The artificial leather according to any one of claims 1 to 4, wherein the filler contains at least one selected from an inorganic filler and an organic filler.