WO2024009907A1 - Napped artificial leather and manufacturing method therefor - Google Patents

Napped artificial leather and manufacturing method therefor Download PDF

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Publication number
WO2024009907A1
WO2024009907A1 PCT/JP2023/024418 JP2023024418W WO2024009907A1 WO 2024009907 A1 WO2024009907 A1 WO 2024009907A1 JP 2023024418 W JP2023024418 W JP 2023024418W WO 2024009907 A1 WO2024009907 A1 WO 2024009907A1
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artificial leather
napped
fibers
napped artificial
web
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PCT/JP2023/024418
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French (fr)
Japanese (ja)
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公男 中山
将司 目黒
明久 岩本
弘行 菱田
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株式会社クラレ
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    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/12—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. gelatine proteins
    • D06N3/14—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. gelatine proteins with polyurethanes

Definitions

  • the present invention relates to napped artificial leather and a method for producing the same.
  • Napped artificial leather which has a suede-like appearance and is used as a surface material for clothing, shoes, furniture, car seats, miscellaneous goods, etc., has a napped surface formed by raising microfibers by raising them.
  • Such napped artificial leather is usually used after being colored, and conventionally dyeing using dyes that can be colored in a wide range of colors from light to deep colors has been widely carried out.
  • Patent Document 1 proposes an artificial leather substrate in which the average area of the polymer elastic body exposed on the sheet surface is 0.1 mm 2 or less.
  • Patent Document 3 proposes suede-like artificial leather that uses pigment-colored fibers and pigment-colored elastomer polymers and has an average napped tone of 10 to 200 ⁇ m.
  • Patent Document 4 discloses that a nonwoven fabric made of short fibers with a single fiber fineness of 0.0001 to 0.5 dtex and an apparent density of 0.300 to 0.700 g/cm 3 and a nap length of A nubuck-like leather-like sheet material has been proposed, which has a particle size of 5 to 500 ⁇ m and is characterized by the absence of a film made of an elastic polymer.
  • Patent Document 5 proposes artificial leather in which the average fiber length of the ultrafine fibers in the napped layer is 250 ⁇ m or more and 500 ⁇ m or less, and the surface coverage of the ultrafine fibers in the napped layer is 60% or more and 100% or less. Further, in Patent Document 6, a resin layer is intermittently formed on the raised surface, the area ratio of the resin portion to the fabric surface is 10 to 90%, and the resin layer is composed of two or more layers. A similar fabric has been proposed.
  • JP2016-69790A Japanese Patent Application Publication No. 2016-11477 Japanese Patent Application Publication No. 2004-143654 JP2006-241620A International Publication No. 2020/003866 International Publication No. 2017/22387
  • the artificial leathers described in Cited Documents 1 and 2 suppress the occurrence of color unevenness, they do not have sufficient mechanical strength such as friction abrasion resistance or tensile strength, and there is room for improvement. Furthermore, the artificial leathers described in Patent Documents 3, 4, and 6 also did not have sufficient mechanical strength such as tensile strength, and there was room for improvement. Furthermore, the leather described in Patent Document 5 does not have a fully satisfactory texture, that is, the texture is rough, and there is room for improvement.
  • the present invention was made in view of the above situation, and an object of the present invention is to provide a raised artificial leather that suppresses the occurrence of color unevenness and has both high mechanical strength and excellent texture.
  • excellent feel means that the texture is close to that of natural leather, such as excellent denseness, flexibility, and good feel.
  • the present invention suppresses the occurrence of color unevenness by setting the content of the polymer elastic body imparted to the nonwoven fabric, the area ratio of the polymer elastic body present on the napped surface, and the napped fiber length to predetermined values. This is based on the discovery that napped artificial leather having both high mechanical strength and excellent texture can be obtained.
  • a napped artificial leather comprising a nonwoven fabric containing ultrafine fibers and a polymeric elastomer and having a napped surface, wherein the content of the polymeric elastomer is 15 to 35% by mass, and the napped surface has a napped surface.
  • the napped artificial leather according to [1] above, wherein the ultrafine fibers are polyester fibers.
  • the napped artificial leather according to [1] or [2] above, wherein the ultrafine fibers have an average fineness of 0.01 to 1.0 dtex.
  • a raised artificial leather that suppresses the occurrence of color unevenness and has both high mechanical strength and excellent texture, and a method for producing the same.
  • FIG. 2 is a conceptual diagram illustrating a method for measuring the napped fiber length of napped artificial leather according to the present invention.
  • the napped artificial leather of the present embodiment includes a nonwoven fabric containing ultrafine fibers and a polymeric elastomer, and has a napped surface, and the content of the polymeric elastomer is 15 to 35% by mass.
  • the area ratio of the polymeric elastic body present on the napped surface is 17% or less, and the napped fiber length is 250 ⁇ m or less.
  • the raised artificial leather of the present embodiment suppresses the occurrence of color unevenness and has high mechanical strength and excellent texture.
  • the napped fiber length means the length of the napped fibers present on the napped surface of napped artificial leather, and the uneven coloring refers to the uneven coloring that occurs when the napped artificial leather is colored. means.
  • the fibers constituting the nonwoven fabric and the polymeric elastomer use different components.
  • polyester fibers may be used as the fibers
  • polyurethane resins may be used as the polymeric elastomer.
  • the fibers and the polymeric elastic material have different coloring properties, resulting in differences in tone and color density between the fibers and the polymeric elastic material.
  • the content of the polymeric elastic material is 15 to 35% by mass, and the area ratio of the polymeric elastic material present on the napped surface is 17% or less, so that the napped surface is It is thought that exposure of the polymeric elastic body is suppressed, and as a result, color unevenness is suppressed.
  • the raised artificial leather of this embodiment has a polymer elastic material content of 15 to 35% by mass, which not only suppresses color unevenness but also has excellent denseness, flexibility, etc., and a good feel to the touch. , the texture becomes similar to natural leather. In other words, it has a good texture.
  • the content of the polymeric elastomer is preferably 16 to 34% by mass, more preferably 16.5 to 33.5% by mass, and still more preferably 17 to 33% by mass, from the viewpoint of obtaining napped artificial leather with a better texture. Mass%.
  • the area ratio of the polymer elastic body present on the napped surface is 17% or less.
  • the area ratio of the polymer elastic body is preferably 15% or less, more preferably 14% or less, still more preferably 13% or less, from the viewpoint of further suppressing uneven dyeing.
  • the area ratio of the polymeric elastic body is preferably 5% or more, more preferably 6% or more, still more preferably 7% or more, from the viewpoint of obtaining napped artificial leather with better flexibility and elasticity.
  • the area ratio of the polymeric elastic body existing on a nape surface is measured and calculated by the following method.
  • the raised surface of the raised artificial leather is photographed at three different locations using a scanning electron microscope (SEM) at a magnification of 50 times.
  • SEM scanning electron microscope
  • calculate the total area of the region in which the polymeric elastic material is present in each of the obtained images and calculate the area ratio of the polymeric elastic material from the obtained total area and the total area of the entire image region. is calculated using the following formula.
  • Area ratio of elastic polymer total area of area where elastic polymer exists / total area of entire image area x 100 (%) Specifically, it is measured and calculated by the method described in the Examples described later.
  • the napped artificial leather of this embodiment has a napped fiber length of 250 ⁇ m or less.
  • the napped fibers When the napped fiber length is 250 ⁇ m or less, the napped fibers have a uniform length in a finely dispersed state, and a napped surface with excellent flexibility and a smooth feel can be formed.
  • the napped fiber length is preferably 150 ⁇ m or less, more preferably 120 ⁇ m or less, and even more preferably 100 ⁇ m or less, from the viewpoint of forming a napped surface with better flexibility and smooth feel.
  • the length of the napped fibers is preferably 40 ⁇ m or more, more preferably 50 ⁇ m or more, and even more preferably 40 ⁇ m or more, from the viewpoint of preventing exposure of the polymeric elastic material at the bottom of the napped fibers, which would cause a decrease in appearance, and maintaining the soft feel of the ultrafine fibers. is 60 ⁇ m or more.
  • the thickness of the napped artificial leather of this embodiment is not particularly limited, but from the viewpoint of obtaining napped artificial leather having both high mechanical strength and excellent texture, it is preferably 0.1 to 1.5 mm, More preferably, it is 0.3 to 1.0 mm.
  • the basis weight of the napped artificial leather is not particularly limited, but from the viewpoint of obtaining napped artificial leather having both high mechanical strength and excellent texture, it is preferably 100 to 1000 g/m 2 , more preferably 150 g/m 2 . ⁇ 800/ m2 .
  • the apparent density of the napped artificial leather of this embodiment is preferably 0.35 g/cm 3 or more, more preferably 0.37 g/cm 3 or more, even more preferably 0.38 g/cm 3 or more, and preferably 0.35 g/cm 3 or more. It is 70 g/cm 3 or less, more preferably 0.50 g/cm 3 or less, even more preferably 0.48 g/cm 3 or less.
  • the apparent density is 0.35 g/cm 3 or more, it has excellent elasticity, and the fibers are prevented from being dragged out when the napped surface is rubbed, making it easy to obtain an elegant napped appearance.
  • the apparent density is 0.70 g/cm 3 or less, it has excellent flexibility.
  • the nonwoven fabric of this embodiment contains ultrafine fibers and an elastic polymer.
  • Nonwoven fabric has a texture similar to natural leather, and from the viewpoint of obtaining high mechanical strength, it has a structure in which multiple ultrafine fibers form fiber bundles and the fiber bundles are entangled (three-dimensional entangled body).
  • the nonwoven fabric is preferably a spunbond nonwoven fabric, and more preferably a spunbond nonwoven fabric containing long ultrafine fibers, from the viewpoint of easily obtaining high mechanical strength and simplifying the production process.
  • long fibers mean continuous fibers that are not short fibers that are intentionally cut after spinning.
  • the nonwoven fabric refers to filaments or continuous fibers that are not short fibers that have been intentionally cut to have a fiber length of about 3 to 80 mm.
  • the nonwoven fabric is preferably one obtained by spinning sea-island type (matrix domain type) composite fibers to obtain a web, subjecting the web to entanglement treatment, and further subjecting it to ultrafine fiber treatment.
  • the ultrafine fibers of the present invention are multicomponent fibers (composite fibers) made of at least two types of spinnable polymers with different chemical or physical properties, which are processed in an appropriate manner before or after being impregnated with a polymeric elastic material. This refers to fibers made into ultra-fine fibers by extracting and removing at least one type of polymer in a step.
  • the multicomponent fiber that generates this ultrafine fiber is an ultrafine fiber generation type fiber. Typical examples thereof include sea-island composite fibers, multilayer laminated composite fibers, radial laminated composite fibers, etc. obtained using methods such as chip blending (mixed spinning) and composite spinning. Among these, sea-island composite fibers are preferable because they cause less damage to the fibers when subjected to entanglement treatment by needle punching or the like, and the average fineness of the ultrafine fibers is uniform.
  • Examples of the resin constituting the ultrafine fibers contained in the nonwoven fabric of this embodiment include polyethylene terephthalate (hereinafter sometimes referred to as "PET”), isophthalic acid-modified PET, sulfoisophthalic acid-modified PET, and cationic dyes.
  • PET polyethylene terephthalate
  • isophthalic acid-modified PET isophthalic acid-modified PET
  • sulfoisophthalic acid-modified PET examples of the resin constituting the ultrafine fibers contained in the nonwoven fabric of this embodiment.
  • Modified PET such as dyeable PET and aromatic polyesters such as polybutylene terephthalate and polyhexamethylene terephthalate; polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate Aliphatic polyesters such as resins; nylons such as nylon 6, nylon 66, nylon 10, nylon 11, nylon 12, and nylon 6-12; fibers such as polypropylene, polyethylene, polybutene, polymethylpentene, and chlorinated polyolefin.
  • modified PET is PET in which at least a portion of the ester-forming dicarboxylic acid monomer units or diol monomer units of unmodified PET are replaced with substitutable monomer units.
  • modified monomer units that replace dicarboxylic acid monomer units include isophthalic acid that replaces terephthalic acid units, sodium sulfoisophthalic acid, sodium sulfonaphthalene dicarboxylic acid, adipic acid, etc. Units are listed. Specific examples of modified monomer units that replace diol monomer units include units derived from diols such as butanediol and hexanediol that replace ethylene glycol units. Among these, polyester resins such as aromatic polyesters and aliphatic polyesters are preferred from the viewpoint of obtaining raised artificial leather having colorability, high mechanical strength, and excellent texture.
  • modified PET such as polyethylene terephthalate (PET), isophthalic acid-modified PET, sulfoisophthalic acid-modified PET, cationic dye-dyeable PET, polybutylene terephthalate, and Aromatic polyesters such as hexamethylene terephthalate; aliphatic polyesters such as polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate resin; nylon 6, nylon 66, nylon Preferred are nylons such as 10, nylon 11, nylon 12, and nylon 6-12; polyolefins such as polypropylene, polyethylene, polybutene, polymethylpentene, and chlorinated polyolefin.
  • PET polyethylene terephthalate
  • isophthalic acid-modified PET isophthalic acid-modified PET
  • sulfoisophthalic acid-modified PET cationic dye-dyeable PET
  • the ultrafine fibers preferably have an average fineness (average fiber diameter) of 0.01 to 1.0 dtex, more preferably from the viewpoint of obtaining napped artificial leather with excellent napped surface density and excellent flexibility and elasticity. is 0.05 to 0.7 dtex, more preferably 0.1 to 0.5 dtex.
  • the resin constituting the ultrafine fibers of this embodiment may contain various additives as long as the effects of the present invention are not impaired.
  • additives include catalysts, colorants, heat resistant agents, flame retardants, lubricants, antifouling agents, optical brighteners, matting agents, gloss improvers, antistatic agents, fragrances, deodorants, and antibacterial agents. , anti-mite agents, inorganic fine particles, etc.
  • Examples of the polymeric elastomer contained in the nonwoven fabric of this embodiment include polyurethane resins, acrylonitrile elastomers, olefin elastomers, polyester elastomers, polyamide elastomers, acrylic elastomers, modified products and copolymers thereof, Examples include mixtures. Among these, polyurethane resins are preferred from the viewpoint of obtaining napped artificial leather with excellent flexibility and elasticity.
  • polyurethane resins include various polyurethane resins obtained by reacting a polymer polyol with a weight average molecular weight of 200 to 6,000, an organic polyisocyanate, and, if necessary, a chain extender at a predetermined molar ratio. Can be mentioned.
  • polymeric polyols include polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly(methyltetramethylene glycol), and copolymers thereof; polybutylene adipate diol, polybutylene sebacate; polyester polyols such as diol, polyhexamethylene adipate diol, poly(3-methyl-1,5-pentylene adipate) diol, poly(3-methyl-1,5-pentylene sebacate) diol, polycaprolactone diol; Copolymers thereof; polycarbonate polyols such as polyhexamethylene carbonate diol, poly(3-methyl-1,5-pentylene carbonate) diol, polypentamethylene carbonate diol, polytetramethylene carbonate diol, and copolymers thereof; polyester Examples include carbonate polyols. Further, if necessary, a polyfunctional alcohol such as a trifluor
  • organic polyisocyanates include non-yellowing diisocyanates such as aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate; Examples include aromatic diisocyanates such as diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate polyurethane. Further, if necessary, a polyfunctional isocyanate such as a trifunctional isocyanate or a tetrafunctional isocyanate may be used in combination. These may be used alone or in combination of two or more.
  • non-yellowing diisocyanates such as aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate,
  • chain extenders include diamines such as hydrazine, ethylenediamine, propylene diamine, hexamethylene diamine, nonamethylene diamine, xylylene diamine, isophorone diamine, piperazine and its derivatives, adipic acid dihydrazide, isophthalic acid dihydrazide; Triamines such as diethylenetriamine; tetramines such as triethylenetetramine; ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis( ⁇ -hydroxyethoxy)benzene, 1,4 - Diols such as cyclohexanediol; triols such as trimethylolpropane; pentaols such as pentaerythritol; amino alcohols such as aminoethyl alcohol and aminopropyl alcohol.
  • diamines such as hydrazine, ethylenediamine, propylene
  • monoamines such as ethylamine, propylamine, butylamine; carboxyl group-containing monoamine compounds such as 4-aminobutanoic acid and 6-aminohexanoic acid; methanol, ethanol, propanol, butanol, etc.
  • Monools may be used in combination.
  • polyurethane resins include polycarbonate urethane, polyether urethane, polyester urethane, polyether ester urethane, polyether carbonate urethane, polyester carbonate urethane, and the like.
  • polycarbonate urethane is preferred from the viewpoint of obtaining napped artificial leather with excellent flexibility and elasticity.
  • the polymeric elastomer may include pigments such as carbon black, colorants such as dyes, coagulation regulators, antioxidants, ultraviolet absorbers, fluorescent agents, antifungal agents, penetrants, Additives such as antifoaming agents, lubricants, water repellents, oil repellents, thickeners, bulking agents, curing accelerators, foaming agents, water-soluble polymer compounds such as polyvinyl alcohol and carboxymethyl cellulose, inorganic fine particles, and conductive agents. May include. However, when production of raised artificial leather is required in small quantities and in many brands, high-quality It is preferable that the molecular elastomer does not contain a colorant such as a pigment or dye.
  • the method for producing napped artificial leather of the present embodiment preferably includes the following steps 1 to 5 from the viewpoint of obtaining napped artificial leather that suppresses the occurrence of color unevenness and has both high mechanical strength and excellent texture.
  • Step 1 Obtaining a web
  • Step 2 Obtaining an entangled web by subjecting the web to an entangling process
  • Step 3 Obtaining an entangled web containing an elastic polymeric material
  • Step 4 Obtaining an entangled web containing an elastic polymeric material
  • Step 1 is a step of obtaining a web.
  • the process of obtaining the web involves melt-spinning sea-island composite fibers to form the web.
  • Methods for obtaining a web by melt-spinning sea-island composite fibers include a method in which the sea-island composite fibers are spun using a spunbond method and then collected on a net without being cut to obtain a web of long fibers; Examples include a method of crimping and cutting the sea-island composite fibers obtained by carding the short fibers of the sea-island composite fibers to obtain a web of short fibers.
  • spunbond method is used to spin the sea-island composite fibers, which are collected on a net without cutting.
  • a method of forming a web of long fibers (hereinafter sometimes referred to as "a method of forming a web of long fibers") is preferred.
  • the spunbond method refers to a method in which a molten strand of sea-island composite fiber is continuously ejected from a spinning nozzle at a predetermined speed using a composite spinning nozzle in which a large number of nozzle holes are arranged in a predetermined pattern.
  • This refers to a method in which the material is discharged from a composite spinning nozzle, stretched while being cooled using high-speed airflow, and deposited on a moving net in the form of a conveyor belt.
  • the web of long fibers formed by the spunbond method may be subjected to a fusing treatment in order to impart stability to its shape. The details of the method for forming a web of long fibers will be described below.
  • the fiber length of the sea-island composite fibers before melt spinning and before being made into ultra-fine fibers is 100 mm or more.
  • the fiber length may be several meters, several hundred meters, several kilometers, or more, as long as it is not unavoidably cut.
  • some of the long fibers may be unavoidably cut and become short fibers.
  • Examples of the island component resin included in the sea-island type composite fiber and which later becomes ultrafine fibers include the same resins as those constituting the ultrafine fibers in the above-mentioned "ultrafine fibers.”
  • As the sea component resin contained in the sea-island composite fiber and removed by extraction or decomposition it is preferable to use a resin that has a different solubility or degradability from the island component resin and has low compatibility. . It is preferable that such a resin is appropriately selected depending on the type of resin of the island component and the manufacturing method.
  • Sea component resins include, for example, olefin resins such as polyethylene, polypropylene, ethylene propylene copolymer, and ethylene vinyl acetate copolymer, and polystyrene, styrene-acrylic copolymer, and styrene-ethylene copolymer dissolved in organic solvents.
  • the resin include resins that have properties and can be dissolved and removed with organic solvents, and water-soluble resins such as water-soluble polyvinyl alcohol. Among these, resins that can be dissolved and removed with organic solvents are preferred from the viewpoint of melt-spinning island component resins with high intrinsic viscosity, and polyethylene is more preferred.
  • the mass ratio of the sea component to the island component (sea component/island component) contained in the sea-island type composite fiber is preferably 10/90 to 60/40, more preferably 20/80 to 50 from the viewpoint of mechanical strength. /50.
  • the number of island components that later become ultrafine fibers in the cross section of the sea-island composite fiber during melt spinning is preferably 5 to 200, more preferably 5 to 200, from the viewpoint of forming a fiber bundle of ultrafine fibers with appropriate voids.
  • the number is 10 to 50, more preferably 10 to 30.
  • the sea-island type composite fibers may be prepared with, for example, dark pigments such as carbon black, white pigments such as zinc white, lead white, lithopone, titanium dioxide, precipitated barium sulfate, and barite powder, weathering agents, and antifungal agents. , hydrolysis inhibitors, lubricants, fine particles, frictional resistance modifiers, etc., may be contained within the range that does not impair the effects of the present invention.
  • the web obtained by melt-spinning the sea-island composite fibers may be subjected to shrinkage treatment by immersing it in hot water of about 60 to 150°C to make the entangled state of the web dense in advance.
  • Step 2 is a step of subjecting the web to an entanglement treatment to obtain an entangled web.
  • the web obtained in step 1 is laminated in multiple layers and then subjected to an entangling treatment such as needle punching or hydroentangling treatment to form an entangled web in which long fibers are entangled in the thickness direction.
  • an entangling treatment such as needle punching or hydroentangling treatment to form an entangled web in which long fibers are entangled in the thickness direction.
  • the number of layers of webs to be stacked is not particularly limited, but from the viewpoint of mechanical strength, it is preferably 4 or more layers, more preferably 8 or more layers, and from the viewpoint of ease of manufacture, preferably 20 or less layers, more preferably It has 16 layers or less.
  • the type of felt needle used is not particularly limited, but from the viewpoint of sufficiently increasing the intertwining of fibers in the thickness direction and obtaining artificial leather with excellent mechanical strength, thin felt needles or It is preferable to use a felting needle with a small number of barbs, such as a one-barb needle. Further, from the viewpoint of suppressing cutting of fibers, the number of barbs in the felt needle is preferably 3 or more, more preferably 5 or more, and still more preferably 6. Further, the number of felt needles used in the needle punch per unit area is not particularly limited, but is preferably 200 to 5,500 needles/cm 2 .
  • An oil agent or an antistatic agent may be applied to the web or the entangled web at any stage from the spinning of the sea-island composite fiber to the entanglement treatment.
  • the basis weight of the entangled web is preferably 100 to 2000 g/m 2 from the viewpoint of obtaining napped artificial leather having both high mechanical strength and excellent texture.
  • heat shrinkage treatment may be performed.
  • fix the form of the entangled web, and smoothen the surface for example, when the surface temperature is 100 to 150 °C It may be pressed with hot rolls, or heated above the softening point of the resin constituting the fibers (island components) in the entangled web, and pressed using cooling rolls whose surface temperature is below the softening point of the resin.
  • the surface temperature of the cooling roll is preferably 30° C. or more lower than the softening point of the resin.
  • Step 3 is a step of impregnating the entangled web with an elastic polymer to obtain an entangled web containing the elastic polymer.
  • an elastomer is impregnated with a polymeric elastomer before removing the sea component. It is preferable that In this way, by impregnating and applying a polymeric elastic material before removing the sea component, the voids formed by removing the sea component can be created between the ultrafine fibers that form the fiber bundle after the sea component is removed. It is formed. As a result, the ultrafine fibers inside the fiber bundle are less likely to be restrained by the elastic polymer, that is, the ultrafine fibers are less likely to be affected by the elastic polymer, and a napped artificial leather with excellent flexibility can be obtained.
  • step 3 the entangled web is impregnated with the elastic polymer using an emulsion or solution containing the elastic polymer, and then the elastic polymer is coagulated to form the entangled web containing the elastic polymer. obtain.
  • the polymeric elastic material By solidifying the polymeric elastic material, the polymeric elastic material can be applied to the voids of the fibers of the entangled web.
  • the method of impregnating the entangled web with the polymer elastomer using an emulsion or solution containing the polymer elastomer is not particularly limited, but a dip-nip method is preferred.
  • Examples of the elastic polymer include those described in ⁇ Elastic Polymer> above, and polyurethane resins are preferred.
  • a solution containing the polymeric elastomer it is preferable to use a solution containing the polymeric elastomer, and use a solvent-based polyurethane in which a polyurethane resin is dissolved in a solvent such as N,N-dimethylformamide (DMF). It is more preferable to obtain an entangled web containing an elastomer polymer.
  • a solvent-based polyurethane in which a polyurethane resin is dissolved in a solvent such as N,N-dimethylformamide (DMF). It is more preferable to obtain an entangled web containing an elastomer polymer.
  • DMF N,N-dimethylformamide
  • the entangled web may be pretreated before being impregnated with the polymeric elastic material. After impregnation, the polymeric elastomer may be selectively removed from the entangled web.
  • Pretreatment of the entangled web includes, for example, a method of coating or impregnating a thermoplastic resin such as polyvinyl alcohol, or a method of coating or impregnating the thermoplastic resin with a gravure coater method, a knife coater method, a pipe coater method, a comma coater method, etc. Examples include a method in which it is present on the surface of an intertwined web or in an intertwined web.
  • Examples of a method for selectively removing the elastic polymer include a method in which the elastic polymer is removed by applying contact pressure to the surface of the entangled web using a nip roll, a squeeze bar, a doctor knife, or the like.
  • the entangled web is impregnated with the polymeric elastic material so that the content of the polymeric elastic material is 15 to 35% by mass in the napped artificial leather, and the entangled web containing the polymeric elastic material is After obtaining the web, it is preferable to selectively remove the elastic polymer from the entangled web so that the area ratio of the elastic polymer present on the napped surface is 17% or less.
  • Examples of methods for coagulating the polymeric elastomer include a method of drying and removing water contained in an emulsion or solution and coagulating it, a method of wet coagulation, and the like.
  • Methods for drying and solidifying include heat treatment in a dryer at 50 to 200°C, infrared heating followed by heat treatment in a dryer, steam treatment followed by heat treatment in a dryer, or ultra-high heat treatment in a dryer. Examples include a method in which heat treatment is performed using a dryer after sonic heating, and a method in which these methods are combined.
  • the entangled web containing the elastomer polymer is immersed in a treatment bath containing a poor solvent for the elastomer polymer, and the elastomer polymer is coagulated into a porous state.
  • Water is preferably used as a poor solvent for the polymeric elastomer, but for example, when polyurethane resin is used as the polymeric elastomer, a good solvent for the polymeric elastomer such as dimethylformamide (DMF) is mixed with water.
  • DMF dimethylformamide
  • It is preferable to use a treatment bath because it is possible to control the solidification state, that is, the size, number, shape, etc. of the large number of pores formed, by appropriately setting the mixing ratio.
  • a heat-sensitive gelling agent When applying a polymer elastomer using an emulsion containing a polymer elastomer, if a heat-sensitive gelling agent is added, it is possible to use a dry method or a combination of methods such as steaming or far-infrared heating. More uniform solidification is possible in the thickness direction. Furthermore, when an elastic polymer is applied using a solution containing an organic solvent and an elastic polymer, more uniform pores can be obtained by using a coagulation modifier in combination. Furthermore, examples of the organic solvent include dimethylformamide, dimethylacetamide, dimethylsulfoxide, and the like. By coagulating the polymer elastic body contained in the entangled web into a porous state, a texture similar to that of natural leather can be obtained. Among these, a method of wet coagulation is preferable, and a method of coagulating the entangled web by immersing it in a treatment solution of water mixed with dimethylformamide as an organic solvent is more preferable.
  • Step 4 is a step of removing sea components from the entangled web containing the elastomer polymer.
  • the microfibers are converted into fiber bundles of microfibers. That is, the fibers in the entangled web are made into ultrafine fibers, and a nonwoven fabric containing ultrafine fibers and an elastic polymer (hereinafter sometimes referred to as a nonwoven fabric containing an elastic polymer) is obtained.
  • Examples of the method for removing the sea component resin include a method using a solvent or a decomposing agent that can selectively remove only the sea component resin.
  • a solvent or a decomposing agent that can selectively remove only the sea component resin.
  • polyethylene from the viewpoint of melt-spinning the resin of the island component having a high intrinsic viscosity, and from this point of view, it is preferable to dissolve and remove the sea component with an organic solvent.
  • the organic solvent for dissolving and removing the sea component include toluene, trichlorethylene, tetrachloroethylene, etc. when the resin of the island component is a polyamide resin or polyester resin and the resin of the sea component is polyethylene.
  • the sea-island composite fibers are melt-spun to obtain a web and before the sea component is removed, the fibers are densified by applying heat shrinkage treatment (fiber shrinkage treatment) using steam, hot water, dry heat, etc. You may let them.
  • heat shrinkage treatment fiber shrinkage treatment
  • the nonwoven fabric containing the polymeric elastomer is dried after removing the sea component resin.
  • the nonwoven fabric containing the polymer elastic body may be cut to a predetermined thickness, if necessary.
  • the basis weight of the nonwoven fabric containing the polymeric elastic material is preferably 140 to 3000 g/m 2 , more preferably 200 to 2000 g/m 2 from the viewpoint of mechanical strength.
  • Step 5 is a step of buffing the nonwoven fabric containing the polymer elastic body obtained in Step 4.
  • the fibers present on the surface of the nonwoven fabric are napped, and napped artificial leather having a napped surface is obtained.
  • the buffing process is preferably carried out using sandpaper or emery paper of 120 to 600 grit, more preferably 320 to 600 grit. In this way, napped artificial leather having napped surfaces on one or both sides can be obtained.
  • the napped fiber length can be adjusted. Fiber length can be shortened.
  • raised artificial leather is subjected to shrinkage processing to add flexibility, kneading to soften it, brushing for reverse sealing, antifouling treatment, hydrophilic treatment, lubricant treatment, softener treatment, and anti-oxidation treatment. Finishing treatments such as agent treatment, ultraviolet absorber treatment, fluorescent agent treatment, and flame retardant treatment may be performed.
  • the napped artificial leather in this embodiment can be colored, and is preferably colored using a dye or a pigment.
  • a dye or a pigment Unlike pigments, which need to be used in combination with resins to make them stick, and whose texture tends to harden, pigments penetrate into the fibers, so there is no need to use resins in combination, there is less concern about deterioration of texture, and it is easy to create a variety of colors by adjusting the type and concentration of the dye. From the viewpoint of easy coloring, it is preferable to dye using a dye.
  • the dye for example, when the ultrafine fiber is formed from a polyester resin, it is preferable to dye it with a disperse dye or a cationic dye.
  • disperse dyes include benzene azo dyes (monoazo, disazo, etc.), heterocyclic azo dyes (thiazole azo, benzothiazo azo, quinoline azo, pyridine azo, imidazole azo, thiophene azo, etc.), anthraquinone dyes, and condensed dyes.
  • examples include dyes such as quinophthalin, styryl, coumarin, etc. These are, for example, commercially available as dyes with the prefix "Disperse”. These may be used alone or in combination of two or more.
  • a dyeing method such as a high-pressure jet dyeing method, a jigger dyeing method, a thermosol continuous dyeing method, a sublimation printing method, etc. can be used.
  • ⁇ Nap-pilled fiber length> After cutting the napped artificial leather in the thickness direction and aligning the napped fibers present on the napped side of the napped artificial leather in the opposite direction using a hair straightening brush, the cross section of the napped artificial leather was examined using a scanning electron microscope (SEM). Photographed at 40x magnification. In the obtained image, draw a line L1 at the root of the ultrafine fibers in the nonwoven fabric, or at the upper limit where the polymeric elastic film is present if an elastic polymeric film exists, and draw the line L1 at the point closest to the observation surface. A line L2 was drawn at the upper limit where the fibers were raised.
  • SEM scanning electron microscope
  • FIG. 3 A conceptual diagram illustrating a method for measuring the napped fiber length of napped artificial leather is shown in FIG. 3.
  • ⁇ Area ratio of elastic polymer> Three images of the raised surface of the raised artificial leather were taken at 50x magnification using a scanning electron microscope (SEM), and each of the obtained images was printed on A4 size paper. Then, the printed paper was placed on an OHP (overhead projector) sheet, and the portion of the polymeric elastic body was painted black and transferred onto the OHP sheet. A pattern on an OHP sheet in which the portion of the polymeric elastic body was painted black was captured by a scanner and an image was formed. Subsequently, using image processing software Image-Pro Premier 9.2 (image-pro plus, manufactured by Media Cybernetics), the total area of the region where the polymeric elastic body existed in the obtained image was determined.
  • SEM scanning electron microscope
  • the area ratio of the polymer elastic body was calculated using the following formula.
  • Area ratio of elastic polymer total area of area where elastic polymer exists / total area of entire image area x 100 (%)
  • Figure 1 is an image of the raised surface taken with a scanning electron microscope (SEM) at a magnification of 50x
  • Figure 2 is a transfer of the polyurethane part of the polymeric elastic material from the image in Figure 1 to an OHP sheet by painting it black. Show images.
  • ⁇ Apparent density> The thickness (mm) and basis weight (g/cm 2 ) were measured in accordance with JIS L 1096:2010, and the apparent density (g/cm 3 ) was determined from these values.
  • ⁇ Tensile strength> Using a 2.5 cm x 16 cm test piece cut from napped artificial leather, a stress-strain curve was obtained according to JIS L1096:2010 8.14.1 "Tensile strength test". The test pieces used were three test pieces cut out along the longitudinal direction of the napped artificial leather and three test pieces cut out along the horizontal direction. The stress at break is read from the stress-strain curve obtained using each test piece, and the average value of the stress of three test pieces cut along the length in the vertical direction and the long length in the horizontal direction are calculated. The average stress value of three test pieces cut along the length was calculated, and the lower value (average value) was taken as the tensile strength.
  • ⁇ Denseness> The denseness of the napped artificial leather was judged visually and by touch using the following criteria.
  • ⁇ Texture> The feel of the napped artificial leather when folded was evaluated visually and by touch using the following criteria. A: Excellent flexibility, elasticity, etc. B: At least one of flexibility and elasticity is poor.
  • Example 1 Prepare polyethylene terephthalate (PET) as the island component and polyethylene as the sea component, and use a melting composite nozzle so that the number of islands is 12, and pressurize so that the mass ratio of the sea component/island component is 35/65. After adjustment, the spinneret temperature was set at 280° C., single-hole discharge was performed at 1.2 g/min, and sea-island composite fibers with a fineness of 3 dtex were spun at a spinning speed of 4000 m/min. The obtained sea-island composite fibers were continuously deposited on a movable net and lightly pressed with a heated metal roll to prevent surface fluffing. The sea-island composite fibers were then peeled from the net and passed between a heated metal roll and a back roll under pressure to produce a web of long fibers with a basis weight of 40 g/m 2 .
  • PET polyethylene terephthalate
  • the laminated web was subjected to needle punching using a 6-barb needle at a punching density of 2050 punches/cm 2 to form an entangled web with a basis weight of 600 g/m 2 .
  • the resulting entangled web was subjected to shrinkage treatment with hot water at 90°C, dried, and then hot pressed to obtain a heat-shrinkable entangled web with a basis weight of 800 g/m 2 .
  • a DMF solution solid content 15% by mass of a polycarbonate polyurethane having a 100% modulus of 4.5 MPa, which is a polymeric elastic material, was added so that the content of the polymeric elastic material in the napped artificial leather was 18% by mass. was impregnated with a heat-shrinked entangled web. After impregnation, the polycarbonate polyurethane present on the surface of the entangled web is selectively removed by applying contact pressure so that the area ratio of the polycarbonate polyurethane present on the napped surface is 5%, and then water is applied.
  • the entangled web to which the polyurethane resin has been applied is dipped in toluene at 85°C while being nipped to dissolve and remove the polyethylene, which is a sea component, and then dried.
  • a nonwoven fabric to which a polyurethane resin was applied as a polymeric elastomer was obtained.
  • the fabric weight of the obtained nonwoven fabric was 600 g/m 2 .
  • the obtained nonwoven fabric was cut in half in the thickness direction to make artificial leather raw material, and the half-cut side was buffed with #180 and #240 sandpaper, and then the non-half-cut side was ground with #320 and #600 sandpaper.
  • a napped artificial leather having a napped surface was obtained by buffing one side of the material.
  • the obtained raised artificial leather was colored by adjusting the disperse dye to a dye concentration of 6% owf, performing high-pressure dyeing at 130 ° C in a circular dyeing machine, and then performing reduction cleaning, oxidation treatment, and water washing.
  • a raised artificial leather was obtained. Table 1 shows the evaluation results of the colored raised artificial leather.
  • Example 2 In Example 1, instead of selectively removing by applying contact pressure so that the area ratio of polycarbonate-based polyurethane existing on the raised surface was 5%, the area ratio of polycarbonate-based polyurethane existing on the raised surface was 9%. Colored napped artificial leather was obtained in the same manner, except that it was selectively removed by applying contact pressure so that the concentration was 0.3%. The evaluation results are shown in Table 1.
  • Example 3 Colored napped artificial leather was obtained in the same manner as in Example 1, except that buffing treatment was performed to obtain napped artificial leather of 0.4 mm. The evaluation results are shown in Table 1.
  • Example 4 In Example 1, a DMF solution (solid content 15%) of polycarbonate polyurethane having a 100% modulus of 4.5 MPa, which is a polymeric elastic material, was added such that the content of the polymeric elastic material in the napped artificial leather was 18% by mass. Instead of impregnating a heat-shrink-treated entangled web, napped artificial leather is impregnated with a DMF solution (solid content 18.5%) of polycarbonate polyurethane, which is a polymeric elastomer and has a 100% modulus of 4.5 MPa. Colored napped artificial leather was obtained in the same manner except that a heat-shrinkable entangled web was impregnated so that the content of the polymeric elastic material therein was 32% by mass. The evaluation results are shown in Table 1.
  • Example 5 In Example 1, one side of the obtained nonwoven fabric was buffed with #180 and #240 sandpaper in order to make it into an artificial leather raw material, and then the untreated side was ground with #320 and #600 sandpaper. A colored napped artificial leather was obtained in the same manner except that a napped artificial leather having a napped surface and a thickness of 1.0 mm was obtained by buffing the surface. The evaluation results are shown in Table 1.
  • Example 6 Prepare polyethylene terephthalate (PET) as the island component and polyethylene as the sea component, and use a melting composite nozzle so that the number of islands is 16, and pressurize so that the mass ratio of the sea component/island component is 35/65. After adjusting the nozzle temperature setting to 280°C and discharging at a single hole discharge rate of 1.2 g/min, and spinning at a spinning speed of 820 m/min, stretching and crimping are performed to obtain sea islands, which are short fibers with a fineness of 4.0 dtex. A composite fiber was obtained. The sea-island composite fibers were then passed through a card to produce a short fiber web.
  • PET polyethylene terephthalate
  • a plurality of the obtained webs were laminated to form a laminated web. Then, the laminated web was subjected to needle punching using a 1-barb needle at a punching density of 2050 punches/cm 2 to form an entangled web with a basis weight of 600 g/m 2 . The resulting entangled web was subjected to shrinkage treatment with hot water at 90°C, dried, and then hot pressed to obtain a heat-shrinkable entangled web with a basis weight of 800 g/m 2 .
  • a DMF solution solid content 15% by mass of a polycarbonate polyurethane having a 100% modulus of 4.5 MPa, which is a polymeric elastic material, was added so that the content of the polymeric elastic material in the napped artificial leather was 18% by mass. was impregnated with a heat-shrinked entangled web. After impregnation, the polycarbonate polyurethane present on the surface of the entangled web is selectively removed by applying contact pressure so that the area ratio of the polycarbonate polyurethane present on the napped surface is 5%, and then water is applied.
  • :DMF was immersed in a DMF aqueous solution having a mass ratio of 70:30 to coagulate the polycarbonate-based polyurethane, thereby imparting polycarbonate-based polyurethane (polyurethane-based resin) to the entangled web.
  • the entangled web to which the polyurethane resin has been applied is dipped in toluene at 85°C while being nipped to dissolve and remove the polyethylene, which is a sea component, and then dried.
  • a nonwoven fabric to which a polyurethane resin was applied as a polymeric elastomer was obtained.
  • the fabric weight of the obtained nonwoven fabric was 820 g/m 2 .
  • Example 1 In Example 1, instead of selectively removing by applying contact pressure so that the area ratio of the polycarbonate-based polyurethane existing on the raised surface was 5%, the area ratio of the polycarbonate-based polyurethane existing on the raised surface was 17%. Colored napped artificial leather was obtained in the same manner, except that it was selectively removed by applying contact pressure so that the concentration was .6%. The evaluation results are shown in Table 1.
  • Example 2 In Example 1, instead of selectively removing by applying contact pressure so that the area ratio of polycarbonate-based polyurethane existing on the raised surface was 5%, the area ratio of polycarbonate-based polyurethane existing on the raised surface was 14%. Coloring was carried out in the same manner except that contact pressure was applied to selectively remove the fibers so that the fiber concentration was 8%, and the length of the napped fibers was adjusted to 250 ⁇ m during the buffing process. Napped artificial leather was obtained. The evaluation results are shown in Table 1.
  • Example 3 In Example 1, instead of the DMF solution (solid content 15%) of polycarbonate polyurethane with a 100% modulus of 4.5 MPa, carbon black was added and colored so that the content was 1.0% by mass. A DMF solution (solid content 15%) of polycarbonate polyurethane with a modulus of 4.5 MPa was used, and the area ratio of polycarbonate polyurethane present on the napped surface was 5%. Instead of selectively removing the polycarbonate polyurethane present in the entangled web by applying contact pressure, the polycarbonate polyurethane present in the entangled web was removed by contact pressure such that the area ratio of the polycarbonate polyurethane present on the napped surface was 18.4%. Colored napped artificial leather was obtained in the same manner, except that 20% of the product was added and selectively removed. The evaluation results are shown in Table 1.
  • Example 4 In Example 1, polyvinyl alcohol was used instead of polyethylene as the sea component, and instead of being immersed in toluene to dissolve and remove polyethylene as a sea component, it was immersed in hot water to dissolve and remove polyethylene. Then, a DMF solution (solid content 15%) of polycarbonate-based polyurethane with a 100% modulus of 4.5 MPa was heat-shrinked so that the content of the polymeric elastomer in the napped artificial leather was 18% by mass.
  • DMF solution solid content 15%
  • (Comparative example 5) Prepare polyethylene terephthalate (PET) as the island component and polyethylene as the sea component, and use a melting composite nozzle so that the number of islands is 16, and pressurize so that the mass ratio of the sea component/island component is 35/65. After adjusting the nozzle temperature setting to 280°C and discharging at a single hole discharge rate of 1.2 g/min, and spinning at a spinning speed of 820 m/min, stretching and crimping are performed to obtain sea islands, which are short fibers with a fineness of 3.6 dtex. A composite fiber was obtained. The obtained sea-island composite fibers were passed through a card to produce a short fiber web.
  • PET polyethylene terephthalate
  • a plurality of sheets of the obtained web were laminated to form a laminated web. Then, the laminated web was subjected to needle punching using a 1-barb needle at a punching density of 2050 punches/cm 2 to form an entangled web with a basis weight of 600 g/m 2 . The resulting entangled web was subjected to shrinkage treatment with hot water at 90°C, dried, and then hot pressed to obtain a heat-shrinkable entangled web with a basis weight of 800 g/m 2 .
  • a DMF solution solid content 15% by mass of a polycarbonate polyurethane having a 100% modulus of 4.5 MPa, which is a polymeric elastic material, was added so that the content of the polymeric elastic material in the napped artificial leather was 40% by mass.
  • :DMF was immersed in a DMF aqueous solution having a mass ratio of 70:30 to coagulate the polycarbonate-based polyurethane, thereby imparting polycarbonate-based polyurethane (polyurethane-based resin) to the entangled web.
  • the entangled web to which the polyurethane resin has been applied is dipped in toluene at 85°C while being nipped to dissolve and remove the polyethylene, which is a sea component, and then dried.
  • a nonwoven fabric to which a polyurethane resin was applied as a polymeric elastomer was obtained.
  • the fabric weight of the obtained nonwoven fabric was 654 g/m 2 .
  • the obtained nonwoven fabric was cut in half in the thickness direction to make artificial leather raw material, and the half-cut side was buffed with #180 and #240 sandpaper, and then the non-half-cut side was ground with #320 and #600 sandpaper.
  • a napped artificial leather having a napped surface was obtained by buffing one side of the material.
  • the obtained raised artificial leather was colored by adjusting the disperse dye to a dye concentration of 6% owf, performing high-pressure dyeing at 130 ° C in a circular dyeing machine, and then performing reduction cleaning, oxidation treatment, and water washing.
  • a raised artificial leather was obtained. Table 1 shows the evaluation results of the colored raised artificial leather.
  • the napped artificial leather obtained in Comparative Example 1 has a polymer elastomer content in the range of 15 to 35% by mass and a napped fiber length of 250 ⁇ m or less;
  • the area ratio of the body was more than 17%, and the polymeric elastic material (polyurethane resin) was visible unevenly from the raised surface, causing uneven dyeing.
  • the napped artificial leather obtained in Comparative Example 2 has an elastic polymer content in the range of 15 to 35% by mass, and the area ratio of the elastic polymer present on the napped surface is 17% or less.
  • the napped fiber length was more than 250 ⁇ m, and the napped fibers were coarsely scattered and had non-uniform lengths, giving a rough feel and no writing.
  • the napped artificial leather obtained in Comparative Example 3 has a polymer elastomer content in the range of 15 to 35% by mass, and a napped fiber length of 250 ⁇ m or less.
  • the area ratio is over 17%. Since the polymeric elastomer contained carbon black, uneven dyeing was somewhat suppressed, but it still occurred to a visible degree.
  • the area ratio of the polymeric elastomer present on the napped surface is 17% or less, and the napped fiber length is 250 ⁇ m or less. did not satisfy the lower limit of the range of 15 to 35% by mass, and this napped artificial leather had poor flexibility and elasticity, and had a hard texture.
  • the napped artificial leather obtained in Comparative Example 5 is a napped artificial leather with a thickness of 0.4 mm using staple fibers, and the napped fiber length is 250 ⁇ m or less. Since the amount exceeds the upper limit of the range of 15 to 35% by mass, and the area ratio of the polymeric elastic material present on the napped surface is more than 17%, the polymeric elastic material (polyurethane resin) is uneven from the napped surface. It was visually recognized that uneven dyeing had occurred, and it did not have sufficient mechanical strength.

Abstract

This napped artificial leather comprises a nonwoven fabric containing ultrafine fibers and a polymer elastic body, and has a napped surface, wherein the content of the polymer elastic body is 15-35 mass%, the area ratio of the polymer elastic body present on the napped surface is at most 17%, and a napped fiber length is at most 250 μm.

Description

立毛人工皮革及びその製造方法Napped artificial leather and its manufacturing method
　本発明は、立毛人工皮革及びその製造方法に関する。 The present invention relates to napped artificial leather and a method for producing the same.
　衣料、靴、家具、カーシート、雑貨製品等の表面素材として用いられるスエードのような外観を有する立毛人工皮革は、極細繊維を起毛処理することにより毛羽立たせて形成する立毛面を有する。このような立毛人工皮革は、通常、着色されて用いられ、従来から、淡色から濃色まで幅広い色に着色することができる染料を用いた染色が広く行われている。 Napped artificial leather, which has a suede-like appearance and is used as a surface material for clothing, shoes, furniture, car seats, miscellaneous goods, etc., has a napped surface formed by raising microfibers by raising them. Such napped artificial leather is usually used after being colored, and conventionally dyeing using dyes that can be colored in a wide range of colors from light to deep colors has been widely carried out.
　従来の立毛人工皮革においては、極細繊維としてポリエステル繊維を用い、高分子弾性体としてポリウレタン樹脂を使用した立毛人工皮革を、分散染料を用いて染色し、その後還元洗浄を行った場合、立毛人工皮革に色ムラが発生し、外観が低下するという問題があった。
　この様な問題に対して、例えば、特許文献１では、人工皮革を表面方向に対して垂直に切断したときの断面において、記人工皮革の立毛部を除く表面から厚み方向２００μｍ以内に存在する、厚み方向に１００μｍ以上の大きさを有する高分子弾性体の塊の表面方向の断面長あたりの数が、０．１～２．５個／ｍｍであることを特徴とする人工皮革が提案されている。
　特許文献２では、シート面部分に露出している高分子弾性体の面積の平均値が０．１ｍｍ２以下である人工皮革用基体が提案されている。 Conventional napped artificial leather uses polyester fibers as ultrafine fibers and polyurethane resin as the polymeric elastic body. When napped artificial leather is dyed with a disperse dye and then subjected to reduction washing, napped artificial leather is created. There was a problem in that color unevenness occurred and the appearance deteriorated.
To deal with such problems, for example, in Patent Document 1, in a cross section when the artificial leather is cut perpendicularly to the surface direction, the artificial leather exists within 200 μm in the thickness direction from the surface excluding the raised portions. An artificial leather has been proposed, characterized in that the number of clumps of polymeric elastic material having a size of 100 μm or more in the thickness direction per cross-sectional length in the surface direction is 0.1 to 2.5 pieces/mm. There is.
Patent Document 2 proposes an artificial leather substrate in which the average area of the polymer elastic body exposed on the sheet surface is 0.1 mm 2 or less.
　また、従来の立毛人工皮革においては、色調や色の濃さが限定され、幅広い色調及び色の濃さに着色することが難しいという問題があった。
　この様な問題に対して、特許文献３では、顔料で着色した繊維と顔料で着色した高分子弾性体を用い、平均立毛調を１０～２００μｍとしたスエード調人工皮革が提案されている。 Furthermore, conventional raised artificial leather has a problem in that the color tone and color depth are limited and it is difficult to color it in a wide range of color tones and color depths.
To address these problems, Patent Document 3 proposes suede-like artificial leather that uses pigment-colored fibers and pigment-colored elastomer polymers and has an average napped tone of 10 to 200 μm.
　また、立毛人工皮革には、緻密性、柔軟性等に優れ、触感が良好であること等、天然皮革が有する風合いに近いことが求められる。
　この様な要求に対して、例えば、特許文献４では、単繊維繊度０．０００１～０．５デシテックス、見掛け密度が０．３００～０．７００ｇ／ｃｍ３の短繊維不織布からなり、立毛長が５～５００μｍであり、かつ弾性重合体からなる膜状物が存在しないことを特徴とするヌバック調皮革様シート状物が提案されている。
　特許文献５では、立毛層における極細繊維の平均繊維長が２５０μｍ以上５００μｍ以下であり、立毛層における極細繊維の表面被覆率が６０％以上１００％以下である人工皮革が提案されている。
　また、特許文献６では、立毛面に断続的に樹脂層が形成されており、樹脂部分の布帛表面に占める面積割合が１０～９０％であり、樹脂層が２層以上で構成されている皮革様布帛が提案されている。 In addition, napped artificial leather is required to have a texture similar to that of natural leather, such as excellent density, flexibility, and a good feel to the touch.
In response to such demands, for example, Patent Document 4 discloses that a nonwoven fabric made of short fibers with a single fiber fineness of 0.0001 to 0.5 dtex and an apparent density of 0.300 to 0.700 g/cm 3 and a nap length of A nubuck-like leather-like sheet material has been proposed, which has a particle size of 5 to 500 μm and is characterized by the absence of a film made of an elastic polymer.
Patent Document 5 proposes artificial leather in which the average fiber length of the ultrafine fibers in the napped layer is 250 μm or more and 500 μm or less, and the surface coverage of the ultrafine fibers in the napped layer is 60% or more and 100% or less.
Further, in Patent Document 6, a resin layer is intermittently formed on the raised surface, the area ratio of the resin portion to the fabric surface is 10 to 90%, and the resin layer is composed of two or more layers. A similar fabric has been proposed.
特開２０１６－６９７９０号公報JP2016-69790A 特開２０１６－１１４７７号公報Japanese Patent Application Publication No. 2016-11477 特開２００４－１４３６５４号公報Japanese Patent Application Publication No. 2004-143654 特開２００６－２４１６２０号公報JP2006-241620A 国際公開第２０２０／００３８６６号International Publication No. 2020/003866 国際公開第２０１７／２２３８７号International Publication No. 2017/22387
　引用文献１及び２に記載の人工皮革は、色ムラの発生が抑制されるものの、摩擦摩耗性や引張強度等の機械的強度が十分ではなく、改善の余地があった。
　また、特許文献３、４、及び６に記載の人工皮革においても、引張強度等の機械的強度が十分ではなく、改善の余地があった。
　また、特許文献５に記載の皮革は、肌触りが十分満足できるものではなく、すなわち肌触りが粗く、改善の余地があった。 Although the artificial leathers described in Cited Documents 1 and 2 suppress the occurrence of color unevenness, they do not have sufficient mechanical strength such as friction abrasion resistance or tensile strength, and there is room for improvement.
Furthermore, the artificial leathers described in Patent Documents 3, 4, and 6 also did not have sufficient mechanical strength such as tensile strength, and there was room for improvement.
Furthermore, the leather described in Patent Document 5 does not have a fully satisfactory texture, that is, the texture is rough, and there is room for improvement.
　一方、引用文献１及び２に記載の方法とは異なる染色ムラを抑制する方法として、立毛繊維長を長くすることで、色ムラを隠蔽する方法も検討されてきた。しかし、この場合、肌触りが悪化し、緻密性が低下するという問題があった。また家具、カーシートなど、人が接触する用途においてはライティングが過度になり、外観が不均一になるという問題があった。 On the other hand, as a method for suppressing uneven dyeing that is different from the methods described in Cited Documents 1 and 2, a method of concealing uneven coloring by increasing the length of the napped fibers has also been studied. However, in this case, there were problems in that the texture deteriorated and the density decreased. Furthermore, in applications where people come into contact with the product, such as furniture and car seats, there is a problem in that the lighting becomes excessive and the appearance becomes uneven.
　また、従来から、立毛人工皮革の機械的強度をより高めるために、立毛人工皮革に長繊維を用いることも検討されている。しかしながら、長繊維を用いると、引張強度等の機械的強度は向上するものの、短繊維からなる立毛人工皮革と比べ、色ムラが発生し易いという問題があった。 Additionally, in order to further increase the mechanical strength of napped artificial leather, the use of long fibers in napped artificial leather has also been considered. However, although the use of long fibers improves mechanical strength such as tensile strength, there is a problem in that color unevenness is more likely to occur compared to napped artificial leather made of short fibers.
　本発明は、このような状況を鑑みてなされたものであり、色ムラの発生が抑制され、高い機械的強度及び優れた風合いを兼ね備えた立毛人工皮革を提供することを目的とする。
　なお、本明細書において、「優れた風合い」とは、緻密性、柔軟性等に優れ、触感が良好であること等、天然皮革が有する風合いに近いことを意味する。 The present invention was made in view of the above situation, and an object of the present invention is to provide a raised artificial leather that suppresses the occurrence of color unevenness and has both high mechanical strength and excellent texture.
In addition, in this specification, "excellent feel" means that the texture is close to that of natural leather, such as excellent denseness, flexibility, and good feel.
　本発明は、不織布に付与された高分子弾性体の含有量、立毛面に存在する前記高分子弾性体の面積比率、及び立毛繊維長を所定の値とすることで、色ムラの発生が抑制され、高い機械的強度及び優れた風合いを兼ね備えた立毛人工皮革が得られること見出したことに基づく。 The present invention suppresses the occurrence of color unevenness by setting the content of the polymer elastic body imparted to the nonwoven fabric, the area ratio of the polymer elastic body present on the napped surface, and the napped fiber length to predetermined values. This is based on the discovery that napped artificial leather having both high mechanical strength and excellent texture can be obtained.
　本発明は、以下の手段を提供する。
　［１］　極細繊維と、高分子弾性体とを含有する不織布を含み、立毛面を有する立毛人工皮革であって、前記高分子弾性体の含有量が１５～３５質量％であり、前記立毛面に存在する前記高分子弾性体の面積比率が１７％以下であり、立毛繊維長が２５０μｍ以下である、立毛人工皮革。
　［２］　前記極細繊維が、ポリエステル系繊維である、上記［１］に記載の立毛人工皮革。
　［３］　前記極細繊維の平均繊度が、０．０１～１．０ｄｔｅｘである、上記［１］又は［２］に記載の立毛人工皮革。
　［４］　前記不織布が、スパンボンド不織布である、上記［１］～［３］のいずれか１項に記載の立毛人工皮革。
　［５］　上記［１］～［４］のいずれか１項に記載の立毛人工皮革の製造方法であって、前記高分子弾性体を含有する絡合ウェブから、海成分を除去して、前記高分子弾性体を含有する不織布を得る工程を含む、立毛人工皮革の製造方法。
　［６］　海島型複合繊維を溶融紡糸してウェブを得る工程を含む、上記［５］に記載の立毛人工皮革の製造方法。
　［７］　前記高分子弾性体を含有する不織布を得る工程において、有機溶剤を用いて前記海成分を溶解除去する、上記［６］に記載の立毛人工皮革の製造方法。
　［８］　溶剤系ポリウレタンを用いて前記高分子弾性体を含有する絡合ウェブを得る工程を有する、上記［５］～［７］のいずれか１項に記載の立毛人工皮革の製造方法。 The present invention provides the following means.
[1] A napped artificial leather comprising a nonwoven fabric containing ultrafine fibers and a polymeric elastomer and having a napped surface, wherein the content of the polymeric elastomer is 15 to 35% by mass, and the napped surface has a napped surface. A napped artificial leather in which the area ratio of the polymeric elastic body present in the area is 17% or less, and the napped fiber length is 250 μm or less.
[2] The napped artificial leather according to [1] above, wherein the ultrafine fibers are polyester fibers.
[3] The napped artificial leather according to [1] or [2] above, wherein the ultrafine fibers have an average fineness of 0.01 to 1.0 dtex.
[4] The raised artificial leather according to any one of [1] to [3] above, wherein the nonwoven fabric is a spunbond nonwoven fabric.
[5] The method for producing the napped artificial leather according to any one of [1] to [4] above, wherein the sea component is removed from the entangled web containing the polymeric elastomer, and the A method for producing napped artificial leather, comprising a step of obtaining a nonwoven fabric containing an elastic polymer.
[6] The method for producing napped artificial leather according to [5] above, which includes the step of melt-spinning sea-island composite fibers to obtain a web.
[7] The method for producing raised artificial leather according to [6] above, wherein in the step of obtaining the nonwoven fabric containing the polymeric elastomer, the sea component is dissolved and removed using an organic solvent.
[8] The method for producing napped artificial leather according to any one of [5] to [7] above, which comprises a step of obtaining an entangled web containing the polymeric elastomer using a solvent-based polyurethane.
　本発明によれば、色ムラの発生が抑制され、高い機械的強度及び優れた風合いを兼ね備えた立毛人工皮革及びその製造方法が提供される。 According to the present invention, there is provided a raised artificial leather that suppresses the occurrence of color unevenness and has both high mechanical strength and excellent texture, and a method for producing the same.
本発明に係る立毛人工皮革の立毛面に存在する高分子弾性体の面積比率を測定するために、立毛面を走査型電子顕微鏡（ＳＥＭ）で倍率５０倍にて撮影した画像である。This is an image of the napped surface of the napped artificial leather according to the present invention taken at a magnification of 50 times using a scanning electron microscope (SEM) in order to measure the area ratio of the polymer elastic body present on the napped surface. 本発明に係る立毛人工皮革の立毛面に存在する高分子弾性体の面積比率を測定するために、図１の画像の高分子弾性体であるポリウレタン部位をＯＨＰシートに黒塗りして転写した画像である。In order to measure the area ratio of the polymeric elastomer present on the napped surface of the napped artificial leather according to the present invention, the polyurethane portion of the polymeric elastomer in the image shown in Figure 1 was painted black and transferred to an OHP sheet. It is. 本発明に係る立毛人工皮革の立毛繊維長の測定方法を説明する概念図である。FIG. 2 is a conceptual diagram illustrating a method for measuring the napped fiber length of napped artificial leather according to the present invention.
　以下、本発明の実施態様（以下、「本実施態様」と称すことがある。）の一例に基づいて説明する。ただし、以下に示す実施態様は、本発明の技術思想を具体化するための例示であって、本発明は以下の記載に限定されない。
　本明細書において、実施態様の好ましい形態を示すが、個々の好ましい形態を２つ以上組み合わせたものもまた、好ましい形態である。数値範囲で示した事項について、いくつかの数値範囲がある場合、それらの下限値と上限値とを選択的に組み合わせて好ましい形態とすることができる。
　なお、本明細書において、「ＸＸ～ＹＹ」との数値範囲の記載がある場合、「ＸＸ以上ＹＹ以下」を意味する。 DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of an embodiment of the present invention (hereinafter sometimes referred to as "this embodiment") will be described below. However, the embodiments shown below are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following description.
In this specification, preferred embodiments are shown, but combinations of two or more individual preferred embodiments are also preferred. When there are several numerical ranges for matters indicated by numerical ranges, the lower and upper limits thereof can be selectively combined to obtain a preferable form.
In addition, in this specification, when a numerical range of "XX to YY" is described, it means "more than or equal to XX and less than or equal to YY."
［立毛人工皮革］
　本実施形態の立毛人工皮革は、極細繊維と、高分子弾性体とを含有する不織布を含み、立毛面を有する立毛人工皮革であって、前記高分子弾性体の含有量が１５～３５質量％であり、前記立毛面に存在する前記高分子弾性体の面積比率が１７％以下であり、立毛繊維長が２５０μｍ以下である。
　本実施形態の前記立毛人工皮革は、色ムラの発生が抑制され、高い機械的強度及び優れた風合いを兼ね備えたものである。
　なお、本明細書において、立毛繊維長とは、立毛人工皮革の立毛面に存在する立毛した繊維の長さを意味し、色ムラとは、立毛人工皮革を着色した際に発生する色ムラを意味する。 [Napped artificial leather]
The napped artificial leather of the present embodiment includes a nonwoven fabric containing ultrafine fibers and a polymeric elastomer, and has a napped surface, and the content of the polymeric elastomer is 15 to 35% by mass. The area ratio of the polymeric elastic body present on the napped surface is 17% or less, and the napped fiber length is 250 μm or less.
The raised artificial leather of the present embodiment suppresses the occurrence of color unevenness and has high mechanical strength and excellent texture.
In addition, in this specification, the napped fiber length means the length of the napped fibers present on the napped surface of napped artificial leather, and the uneven coloring refers to the uneven coloring that occurs when the napped artificial leather is colored. means.
　本実施形態の立毛人工皮革が、上記構成を有することで上記効果を奏する理由については定かではないが、次のように考えられる。
　一般的に、立毛人工皮革においては、不織布を構成する繊維と、高分子弾性体は、異なる成分を用いる。例えば、繊維としてポリエステル系繊維、高分子弾性体としてポリウレタン系樹脂を用いることがある。この様な立毛人工皮革を、分散染料等、着色剤を用いて着色すると、繊維と高分子弾性体では着色性が異なるため、繊維と高分子弾性体では色調や色の濃さに差が発生する場合がある。特に、立毛面に露出した高分子弾性体と、立毛面に存在する繊維との間で色調や色の濃さに差が発生すると、この違いが色ムラとして確認されるものと考えられる。
　本発明の立毛人工皮革においては、高分子弾性体の含有量が１５～３５質量％であり、かつ立毛面に存在する高分子弾性体の面積比率が１７％以下であることで、立毛面に高分子弾性体が露出することが抑制され、その結果色ムラが抑制されると考えられる。 The reason why the raised artificial leather of this embodiment achieves the above effects by having the above structure is not clear, but it is thought to be as follows.
Generally, in napped artificial leather, the fibers constituting the nonwoven fabric and the polymeric elastomer use different components. For example, polyester fibers may be used as the fibers, and polyurethane resins may be used as the polymeric elastomer. When such napped artificial leather is colored with a coloring agent such as a disperse dye, the fibers and the polymeric elastic material have different coloring properties, resulting in differences in tone and color density between the fibers and the polymeric elastic material. There are cases where In particular, if a difference in color tone or color density occurs between the polymeric elastic body exposed on the napped surface and the fibers present on the napped surface, this difference is considered to be observed as color unevenness.
In the napped artificial leather of the present invention, the content of the polymeric elastic material is 15 to 35% by mass, and the area ratio of the polymeric elastic material present on the napped surface is 17% or less, so that the napped surface is It is thought that exposure of the polymeric elastic body is suppressed, and as a result, color unevenness is suppressed.
　本実施形態の立毛人工皮革は、高分子弾性体の含有量が１５～３５質量％であることで、色ムラが抑制されるだけでなく、緻密性、柔軟性等に優れ、触感が良好となり、風合いが天然皮革に類似するものとなる。すなわち、良好な風合いとなる。
　高分子弾性体の含有量は、より良好な風合いを有する立毛人工皮革を得る観点から、好ましくは１６～３４質量％、より好ましくは１６．５～３３．５質量％、さらに好ましくは１７～３３質量％である。 The raised artificial leather of this embodiment has a polymer elastic material content of 15 to 35% by mass, which not only suppresses color unevenness but also has excellent denseness, flexibility, etc., and a good feel to the touch. , the texture becomes similar to natural leather. In other words, it has a good texture.
The content of the polymeric elastomer is preferably 16 to 34% by mass, more preferably 16.5 to 33.5% by mass, and still more preferably 17 to 33% by mass, from the viewpoint of obtaining napped artificial leather with a better texture. Mass%.
　本実施形態の立毛人工皮革は、立毛面に存在する前記高分子弾性体の面積比率が１７％以下である。高分子弾性体の面積比率を１７％以下とすることで、立毛面から高分子弾性体が露出することが抑制され、高分子弾性体を全く又は極僅かしか視認することができず、色ムラが抑制される。高分子弾性体の面積比率は、より染色ムラを抑制する観点から、１５％以下が好ましく、より好ましくは１４％以下、さらに好ましくは１３％以下である。そして、高分子弾性体の面積比率は、より柔軟性、及び弾力性に優れる立毛人工皮革を得る観点から、好ましくは５％以上、より好ましくは６％以上、さらに好ましくは７％以上である。 In the napped artificial leather of this embodiment, the area ratio of the polymer elastic body present on the napped surface is 17% or less. By setting the area ratio of the polymer elastic body to 17% or less, exposure of the polymer elastic body from the napped surface is suppressed, and no or only a small amount of the polymer elastic body can be visually recognized, resulting in color unevenness. is suppressed. The area ratio of the polymer elastic body is preferably 15% or less, more preferably 14% or less, still more preferably 13% or less, from the viewpoint of further suppressing uneven dyeing. The area ratio of the polymeric elastic body is preferably 5% or more, more preferably 6% or more, still more preferably 7% or more, from the viewpoint of obtaining napped artificial leather with better flexibility and elasticity.
　なお、本明細書において、「立毛面に存在する高分子弾性体の面積比率」は、以下の方法により測定及び算出されるものである。
　立毛人工皮革の立毛面を、走査型電子顕微鏡（ＳＥＭ）を用い、倍率５０倍にて、それぞれ異なる３箇所を撮影する。得られたそれぞれの画像を、画像処理装置等を用いて、高分子弾性体が存在する領域の総面積を求め、求めた総面積と画像全領域の総面積から、高分子弾性体の面積比率を下記式により算出する。
　高分子弾性体の面積比率＝高分子弾性体が存在する領域の総面積／画像全領域の総面積×１００（％）
　具体的には後述する実施例に記載の方法で測定及び算出されるものである。 In addition, in this specification, "the area ratio of the polymeric elastic body existing on a nape surface" is measured and calculated by the following method.
The raised surface of the raised artificial leather is photographed at three different locations using a scanning electron microscope (SEM) at a magnification of 50 times. Using an image processing device or the like, calculate the total area of the region in which the polymeric elastic material is present in each of the obtained images, and calculate the area ratio of the polymeric elastic material from the obtained total area and the total area of the entire image region. is calculated using the following formula.
Area ratio of elastic polymer = total area of area where elastic polymer exists / total area of entire image area x 100 (%)
Specifically, it is measured and calculated by the method described in the Examples described later.
　本実施形態の立毛人工皮革は、立毛繊維長が２５０μｍ以下である。立毛繊維長が２５０μｍ以下であることで、立毛が細かく分散した状態で均一な長さを有することとなり、柔軟性に優れ、スムースな感触の立毛面を形成することができる。立毛繊維長は、より柔軟性に優れ、スムースな感触の立毛面を形成する観点から、好ましくは１５０μｍ以下、より好ましくは１２０μｍ以下、さらに好ましくは１００μｍ以下である。そして、立毛繊維長は、外観低下要因となる立毛繊維下部の高分子弾性体の露出を防ぎ、かつ極細繊維の柔らかい触感を保持させる観点から、好ましくは４０μｍ以上、より好ましくは５０μｍ以上、さらに好ましくは６０μｍ以上である。 The napped artificial leather of this embodiment has a napped fiber length of 250 μm or less. When the napped fiber length is 250 μm or less, the napped fibers have a uniform length in a finely dispersed state, and a napped surface with excellent flexibility and a smooth feel can be formed. The napped fiber length is preferably 150 μm or less, more preferably 120 μm or less, and even more preferably 100 μm or less, from the viewpoint of forming a napped surface with better flexibility and smooth feel. The length of the napped fibers is preferably 40 μm or more, more preferably 50 μm or more, and even more preferably 40 μm or more, from the viewpoint of preventing exposure of the polymeric elastic material at the bottom of the napped fibers, which would cause a decrease in appearance, and maintaining the soft feel of the ultrafine fibers. is 60 μm or more.
　本実施形態の立毛人工皮革の厚さは、特に限定されるものではないが、高い機械的強度及び優れた風合いを兼ね備えた立毛人工皮革を得る観点から、好ましくは０．１～１．５ｍｍ、より好ましくは０．３～１．０ｍｍである。
　また、立毛人工皮革の目付は、特に限定されるものではないが、高い機械的強度及び優れた風合いを兼ね備えた立毛人工皮革を得る観点から、好ましくは１００～１０００ｇ／ｍ２、さらに好ましくは１５０～８００／ｍ２である。 The thickness of the napped artificial leather of this embodiment is not particularly limited, but from the viewpoint of obtaining napped artificial leather having both high mechanical strength and excellent texture, it is preferably 0.1 to 1.5 mm, More preferably, it is 0.3 to 1.0 mm.
Furthermore, the basis weight of the napped artificial leather is not particularly limited, but from the viewpoint of obtaining napped artificial leather having both high mechanical strength and excellent texture, it is preferably 100 to 1000 g/m 2 , more preferably 150 g/m 2 . ~800/ m2 .
　本実施形態の立毛人工皮革の見かけ密度は、好ましくは０．３５ｇ／ｃｍ３以上、より好ましくは０．３７ｇ／ｃｍ３以上、さらに好ましくは０．３８ｇ／ｃｍ３以上であり、好ましくは０．７０ｇ／ｃｍ３以下、より好ましくは０．５０ｇ／ｃｍ３以下、さらに好ましくは０．４８ｇ／ｃｍ３以下である。見かけ密度が０．３５ｇ／ｃｍ３以上であることで、弾力性に優れ、また、立毛面が摩擦された際に繊維が引きずり出されることが抑制され、優美な立毛の外観が得られ易い。また、見かけ密度が０．７０ｇ／ｃｍ３以下であることで、柔軟性に優れるものとなる。 The apparent density of the napped artificial leather of this embodiment is preferably 0.35 g/cm 3 or more, more preferably 0.37 g/cm 3 or more, even more preferably 0.38 g/cm 3 or more, and preferably 0.35 g/cm 3 or more. It is 70 g/cm 3 or less, more preferably 0.50 g/cm 3 or less, even more preferably 0.48 g/cm 3 or less. When the apparent density is 0.35 g/cm 3 or more, it has excellent elasticity, and the fibers are prevented from being dragged out when the napped surface is rubbed, making it easy to obtain an elegant napped appearance. Moreover, since the apparent density is 0.70 g/cm 3 or less, it has excellent flexibility.
＜不織布＞
　本実施形態の不織布は、極細繊維と、高分子弾性体とを含有する。不織布は、天然皮革に近い風合いを有し、高い機械的強度を得る観点から、複数の極細繊維が繊維束を形成し、その繊維束が絡合してなる構造（三次元絡合体）を有するものであることが好ましい。
　また、不織布は、高い機械的強度を得やすい点、および生産工程を簡略化できる観点から、スパンボンド不織布であることが好ましく、長繊維の極細繊維を含むスパンボンド不織布であることがより好ましい。
　なお、長繊維とは、紡糸後に意図的にカットされた短繊維ではない、連続的な繊維であることを意味する。具体的には、繊維長が３～８０ｍｍ程度になるように意図的に切断されたような短繊維ではないフィラメントまたは連続繊維を意味する。
　また、不織布は、海島型（マトリクス・ドメイン型）複合繊維を紡糸してウェブを得、そのウェブを絡合処理し、さらに極細繊維化処理することにより得られるものであることが好ましい。 <Nonwoven fabric>
The nonwoven fabric of this embodiment contains ultrafine fibers and an elastic polymer. Nonwoven fabric has a texture similar to natural leather, and from the viewpoint of obtaining high mechanical strength, it has a structure in which multiple ultrafine fibers form fiber bundles and the fiber bundles are entangled (three-dimensional entangled body). Preferably.
In addition, the nonwoven fabric is preferably a spunbond nonwoven fabric, and more preferably a spunbond nonwoven fabric containing long ultrafine fibers, from the viewpoint of easily obtaining high mechanical strength and simplifying the production process.
Note that long fibers mean continuous fibers that are not short fibers that are intentionally cut after spinning. Specifically, it refers to filaments or continuous fibers that are not short fibers that have been intentionally cut to have a fiber length of about 3 to 80 mm.
Further, the nonwoven fabric is preferably one obtained by spinning sea-island type (matrix domain type) composite fibers to obtain a web, subjecting the web to entanglement treatment, and further subjecting it to ultrafine fiber treatment.
（極細繊維）
　本発明の極細繊維とは、化学的または物理的性質の異なる少なくとも２種類以上の可紡性ポリマーからなる多成分系繊維（複合繊維）を、高分子弾性体を含浸させる前または後の適当な段階で少なくとも１種類のポリマーを抽出除去することにより極細化した繊維のことである。この極細繊維を発生させる多成分系繊維が極細繊維発生型繊維である。その代表例としては、チップブレンド（混合紡糸）方式や複合紡糸方式等の方法を用いて得られる海島型複合繊維、多層積層型複合繊維、放射型積層型複合繊維等がある。これらの中でも、海島型複合繊維が、ニードルパンチ等により絡合処理を行った際の繊維損傷が少なく、かつ極細繊維の平均繊度の均一性の点で好ましい。 (Ultra-fine fiber)
The ultrafine fibers of the present invention are multicomponent fibers (composite fibers) made of at least two types of spinnable polymers with different chemical or physical properties, which are processed in an appropriate manner before or after being impregnated with a polymeric elastic material. This refers to fibers made into ultra-fine fibers by extracting and removing at least one type of polymer in a step. The multicomponent fiber that generates this ultrafine fiber is an ultrafine fiber generation type fiber. Typical examples thereof include sea-island composite fibers, multilayer laminated composite fibers, radial laminated composite fibers, etc. obtained using methods such as chip blending (mixed spinning) and composite spinning. Among these, sea-island composite fibers are preferable because they cause less damage to the fibers when subjected to entanglement treatment by needle punching or the like, and the average fineness of the ultrafine fibers is uniform.
　本実施形態の不織布に含まれる極細繊維を構成する樹脂としては、例えば、例えば、ポリエチレンテレフタレート（以下、「ＰＥＴ」と称すことがある。）、イソフタル酸変性ＰＥＴ、スルホイソフタル酸変性ＰＥＴ、カチオン染料可染性ＰＥＴ等の変性ＰＥＴやポリブチレンテレフタレート、ポリヘキサメチレンテレフタレート等の芳香族ポリエステル；ポリ乳酸、ポリエチレンサクシネート、ポリブチレンサクシネート、ポリブチレンサクシネートアジペート、ポリヒドロキシブチレート－ポリヒドロキシバリレート樹脂等の脂肪族ポリエステル；ナイロン６、ナイロン６６、ナイロン１０、ナイロン１１、ナイロン１２、ナイロン６－１２等のナイロン；ポリプロピレン、ポリエチレン、ポリブテン、ポリメチルペンテン、塩素系ポリオレフィン等の繊維が挙げられる。なお、変性ＰＥＴは、未変性ＰＥＴのエステル形成性のジカルボン酸系単量体単位、または、ジオール系単量体単位の少なくとも一部を置換可能な単量体単位で置き換えたＰＥＴである。ジカルボン酸系単量体単位を置換する変性単量体単位の具体例としては、例えば、テレフタル酸単位を置換するイソフタル酸、ナトリウムスルホイソフタル酸、ナトリウムスルホナフタレンジカルボン酸、アジピン酸、等に由来する単位が挙げられる。また、ジオール系単量体単位を置換する変性単量体単位の具体例としては、例えば、エチレングリコール単位を置換するブタンジオール、ヘキサンジオール等のジオールに由来する単位が挙げられる。
　これらの中でも、着色性や、高い機械的強度及び優れた風合いを兼ね備えた立毛人工皮革を得る観点から、芳香族ポリエステルや脂肪族ポリエステル等のポリエステル系樹脂が好ましい。また、紡糸する際の生産性、機械的強度等の観点から、ポリエチレンテレフタレート（ＰＥＴ）、イソフタル酸変性ＰＥＴ、スルホイソフタル酸変性ＰＥＴ、カチオン染料可染性ＰＥＴ等の変性ＰＥＴやポリブチレンテレフタレート、ポリヘキサメチレンテレフタレート等の芳香族ポリエステル；ポリ乳酸、ポリエチレンサクシネート、ポリブチレンサクシネート、ポリブチレンサクシネートアジペート、ポリヒドロキシブチレート－ポリヒドロキシバリレート樹脂等の脂肪族ポリエステル；ナイロン６、ナイロン６６、ナイロン１０、ナイロン１１、ナイロン１２、ナイロン６－１２等のナイロン；ポリプロピレン、ポリエチレン、ポリブテン、ポリメチルペンテン、塩素系ポリオレフィンなどのポリオレフィン等が好ましい。 Examples of the resin constituting the ultrafine fibers contained in the nonwoven fabric of this embodiment include polyethylene terephthalate (hereinafter sometimes referred to as "PET"), isophthalic acid-modified PET, sulfoisophthalic acid-modified PET, and cationic dyes. Modified PET such as dyeable PET and aromatic polyesters such as polybutylene terephthalate and polyhexamethylene terephthalate; polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate Aliphatic polyesters such as resins; nylons such as nylon 6, nylon 66, nylon 10, nylon 11, nylon 12, and nylon 6-12; fibers such as polypropylene, polyethylene, polybutene, polymethylpentene, and chlorinated polyolefin. Note that modified PET is PET in which at least a portion of the ester-forming dicarboxylic acid monomer units or diol monomer units of unmodified PET are replaced with substitutable monomer units. Specific examples of modified monomer units that replace dicarboxylic acid monomer units include isophthalic acid that replaces terephthalic acid units, sodium sulfoisophthalic acid, sodium sulfonaphthalene dicarboxylic acid, adipic acid, etc. Units are listed. Specific examples of modified monomer units that replace diol monomer units include units derived from diols such as butanediol and hexanediol that replace ethylene glycol units.
Among these, polyester resins such as aromatic polyesters and aliphatic polyesters are preferred from the viewpoint of obtaining raised artificial leather having colorability, high mechanical strength, and excellent texture. In addition, from the viewpoint of productivity and mechanical strength during spinning, modified PET such as polyethylene terephthalate (PET), isophthalic acid-modified PET, sulfoisophthalic acid-modified PET, cationic dye-dyeable PET, polybutylene terephthalate, and Aromatic polyesters such as hexamethylene terephthalate; aliphatic polyesters such as polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate resin; nylon 6, nylon 66, nylon Preferred are nylons such as 10, nylon 11, nylon 12, and nylon 6-12; polyolefins such as polypropylene, polyethylene, polybutene, polymethylpentene, and chlorinated polyolefin.
　極細繊維は、立毛面の緻密性に優れ、柔軟性及び弾力性に優れる立毛人工皮革を得る観点から、平均繊度（平均繊維径）が０．０１～１．０ｄｔｅｘであることが好ましく、より好ましくは０．０５～０．７ｄｔｅｘ、さらに好ましくは０．１～０．５ｄｔｅｘである。 The ultrafine fibers preferably have an average fineness (average fiber diameter) of 0.01 to 1.0 dtex, more preferably from the viewpoint of obtaining napped artificial leather with excellent napped surface density and excellent flexibility and elasticity. is 0.05 to 0.7 dtex, more preferably 0.1 to 0.5 dtex.
　本実施形態の極細繊維を構成する樹脂は、本発明の効果を損なわない範囲で、各種添加剤を含んでもよい。添加剤としては、例えば、触媒、着色剤、耐熱剤、難燃剤、滑剤、防汚剤、蛍光増白剤、艶消剤、光沢改良剤、制電剤、芳香剤、消臭剤、抗菌剤、防ダニ剤、無機微粒子等が挙げられる。 The resin constituting the ultrafine fibers of this embodiment may contain various additives as long as the effects of the present invention are not impaired. Examples of additives include catalysts, colorants, heat resistant agents, flame retardants, lubricants, antifouling agents, optical brighteners, matting agents, gloss improvers, antistatic agents, fragrances, deodorants, and antibacterial agents. , anti-mite agents, inorganic fine particles, etc.
＜高分子弾性体＞
　本実施形態の不織布が含有する高分子弾性体としては、例えば、ポリウレタン系樹脂、アクリロニトリル系エラストマー、オレフィン系エラストマー、ポリエステル系エラストマー、ポリアミド系エラストマー、アクリル系エラストマー、これらの変成物や共重合体、混合物等が挙げられる。これらの中でも、柔軟性及び弾力性に優れる立毛人工皮革を得る観点から、ポリウレタン系樹脂が好ましい。 <Elastic polymer>
Examples of the polymeric elastomer contained in the nonwoven fabric of this embodiment include polyurethane resins, acrylonitrile elastomers, olefin elastomers, polyester elastomers, polyamide elastomers, acrylic elastomers, modified products and copolymers thereof, Examples include mixtures. Among these, polyurethane resins are preferred from the viewpoint of obtaining napped artificial leather with excellent flexibility and elasticity.
　ポリウレタン系樹脂としては、重量平均分子量２００～６０００の高分子ポリオールと有機ポリイソシアネ－トと、必要に応じて鎖伸長剤とを、所定のモル比で反応させることにより得られる各種のポリウレタン系樹脂が挙げられる。 Examples of polyurethane resins include various polyurethane resins obtained by reacting a polymer polyol with a weight average molecular weight of 200 to 6,000, an organic polyisocyanate, and, if necessary, a chain extender at a predetermined molar ratio. Can be mentioned.
　高分子ポリオールの具体例としては、例えば、ポリエチレングリコール、ポリプロピレングリコール、ポリテトラメチレングリコール、ポリ（メチルテトラメチレングリコール）等のポリエーテル系ポリオール及びその共重合体；ポリブチレンアジペートジオール、ポリブチレンセバケートジオール、ポリヘキサメチレンアジペートジオール、ポリ（３－メチル－１，５－ペンチレンアジペート）ジオール、ポリ（３－メチル－１，５－ペンチレンセバケート）ジオール、ポリカプロラクトンジオール等のポリエステル系ポリオール及びその共重合体；ポリヘキサメチレンカーボネートジオール、ポリ（３－メチル－１，５－ペンチレンカーボネート）ジオール、ポリペンタメチレンカーボネートジオール、ポリテトラメチレンカーボネートジオール等のポリカーボネート系ポリオール及びその共重合体；ポリエステルカーボネートポリオール等が挙げられる。また、必要に応じて、３官能アルコールや４官能アルコール等の多官能アルコール、または、エチレングリコール等の短鎖アルコールを併用してもよい。これらは単独で用いても、２種以上を組み合わせて用いてもよい。 Specific examples of polymeric polyols include polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly(methyltetramethylene glycol), and copolymers thereof; polybutylene adipate diol, polybutylene sebacate; polyester polyols such as diol, polyhexamethylene adipate diol, poly(3-methyl-1,5-pentylene adipate) diol, poly(3-methyl-1,5-pentylene sebacate) diol, polycaprolactone diol; Copolymers thereof; polycarbonate polyols such as polyhexamethylene carbonate diol, poly(3-methyl-1,5-pentylene carbonate) diol, polypentamethylene carbonate diol, polytetramethylene carbonate diol, and copolymers thereof; polyester Examples include carbonate polyols. Further, if necessary, a polyfunctional alcohol such as a trifunctional alcohol or a tetrafunctional alcohol, or a short chain alcohol such as ethylene glycol may be used in combination. These may be used alone or in combination of two or more.
　有機ポリイソシアネートの具体例としては、例えば、ヘキサメチレンジイソシアネート、イソホロンジイソシアネート、ノルボルネンジイソシアネート、４，４’－ジシクロヘキシルメタンジイソシアネート等の脂肪族あるいは脂環族ジイソシアネート等の無黄変型ジイソシアネート；２，４－トリレンジイソシアネート、２，６－トリレンジイソシアネート、４，４’－ジフェニルメタンジイソシアネート、キシリレンジイソシアネートポリウレタン等の芳香族ジイソシアネート、等が挙げられる。また、必要に応じて、３官能イソシアネートや４官能イソシアネート等の多官能イソシアネートを併用してもよい。これらは単独で用いても、２種以上を組み合わせて用いてもよい。 Specific examples of organic polyisocyanates include non-yellowing diisocyanates such as aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate; Examples include aromatic diisocyanates such as diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate polyurethane. Further, if necessary, a polyfunctional isocyanate such as a trifunctional isocyanate or a tetrafunctional isocyanate may be used in combination. These may be used alone or in combination of two or more.
　鎖伸長剤の具体例としては、例えば、ヒドラジン、エチレンジアミン、プロピレンジアミン、ヘキサメチレンジアミン、ノナメチレンジアミン、キシリレンジアミン、イソホロンジアミン、ピペラジン及びその誘導体、アジピン酸ジヒドラジド、イソフタル酸ジヒドラジド等のジアミン類；ジエチレントリアミン等のトリアミン類；トリエチレンテトラミン等のテトラミン類；エチレングリコール、プロピレングリコール、１，４－ブタンジオール、１，６－ヘキサンジオール、１，４－ビス（β－ヒドロキシエトキシ）ベンゼン、１，４－シクロヘキサンジオール等のジオール類；トリメチロールプロパン等のトリオール類；ペンタエリスリトール等のペンタオール類；アミノエチルアルコール、アミノプロピルアルコール等のアミノアルコール類等が挙げられる。これらは単独で用いても、２種以上を組み合わせて用いてもよい。また、鎖伸長反応時に、鎖伸長剤とともに、エチルアミン、プロピルアミン、ブチルアミン等のモノアミン類；４－アミノブタン酸、６－アミノヘキサン酸等のカルボキシル基含有モノアミン化合物；メタノール、エタノール、プロパノール、ブタノール等のモノオール類を併用してもよい。 Specific examples of chain extenders include diamines such as hydrazine, ethylenediamine, propylene diamine, hexamethylene diamine, nonamethylene diamine, xylylene diamine, isophorone diamine, piperazine and its derivatives, adipic acid dihydrazide, isophthalic acid dihydrazide; Triamines such as diethylenetriamine; tetramines such as triethylenetetramine; ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis(β-hydroxyethoxy)benzene, 1,4 - Diols such as cyclohexanediol; triols such as trimethylolpropane; pentaols such as pentaerythritol; amino alcohols such as aminoethyl alcohol and aminopropyl alcohol. These may be used alone or in combination of two or more. In addition, during the chain extension reaction, monoamines such as ethylamine, propylamine, butylamine; carboxyl group-containing monoamine compounds such as 4-aminobutanoic acid and 6-aminohexanoic acid; methanol, ethanol, propanol, butanol, etc. Monools may be used in combination.
　ポリウレタン系樹脂の具体例としては、例えば、ポリカーボネートウレタン、ポリエーテルウレタン、ポリエステルウレタン、ポリエーテルエステルウレタン、ポリエーテルカーボネートウレタン、ポリエステルカーボネートウレタン等が挙げられる。これらの中でも、柔軟性及び弾力性に優れる立毛人工皮革を得る観点から、ポリカーボネートウレタンが好ましい。 Specific examples of polyurethane resins include polycarbonate urethane, polyether urethane, polyester urethane, polyether ester urethane, polyether carbonate urethane, polyester carbonate urethane, and the like. Among these, polycarbonate urethane is preferred from the viewpoint of obtaining napped artificial leather with excellent flexibility and elasticity.
　高分子弾性体は、本発明の効果を損なわない範囲で、カーボンブラック等の顔料や染料等の着色剤、凝固調節剤、酸化防止剤、紫外線吸収剤、蛍光剤、防黴剤、浸透剤、消泡剤、滑剤、撥水剤、撥油剤、増粘剤、増量剤、硬化促進剤、発泡剤、ポリビニルアルコールやカルボキシメチルセルロース等の水溶性高分子化合物、無機微粒子、導電剤等の添加剤を含んでもよい。ただし、少量多銘柄の立毛人工皮革の生産が求められる場合においては、高分子弾性体に含まれる顔料や染料等のコンタミネーションによる工程の汚染を抑制して、生産性を向上させる観点から、高分子弾性体は顔料や染料等の着色剤を含まないことが好ましい。 The polymeric elastomer may include pigments such as carbon black, colorants such as dyes, coagulation regulators, antioxidants, ultraviolet absorbers, fluorescent agents, antifungal agents, penetrants, Additives such as antifoaming agents, lubricants, water repellents, oil repellents, thickeners, bulking agents, curing accelerators, foaming agents, water-soluble polymer compounds such as polyvinyl alcohol and carboxymethyl cellulose, inorganic fine particles, and conductive agents. May include. However, when production of raised artificial leather is required in small quantities and in many brands, high-quality It is preferable that the molecular elastomer does not contain a colorant such as a pigment or dye.
［立毛人工皮革の製造方法］
　本実施形態の立毛人工皮革の製造方法は、色ムラの発生が抑制され、高い機械的強度及び優れた風合いを兼ね備えた立毛人工皮革を得る観点から、下記工程１～５を含むことが好ましい。
工程１：ウェブを得る工程
工程２：ウェブに絡合処理をして絡合ウェブを得る工程
工程３：高分子弾性体を含有する絡合ウェブを得る工程
工程４：高分子弾性体を含有する絡合ウェブから、海成分を除去する工程
工程５：バフィング処理する工程 [Method for manufacturing raised artificial leather]
The method for producing napped artificial leather of the present embodiment preferably includes the following steps 1 to 5 from the viewpoint of obtaining napped artificial leather that suppresses the occurrence of color unevenness and has both high mechanical strength and excellent texture.
Step 1: Obtaining a web Step 2: Obtaining an entangled web by subjecting the web to an entangling process Step 3: Obtaining an entangled web containing an elastic polymeric material Step 4: Obtaining an entangled web containing an elastic polymeric material Step 5 of removing sea components from the entangled web: Buffing process
＜工程１＞
　工程１は、ウェブを得る工程である。
　本実施形態においては、色ムラの発生が抑制され、高い機械的強度及び優れた風合いを兼ね備えた立毛人工皮革を得る観点から、ウェブを得る工程は、海島型複合繊維を溶融紡糸してウェブを得ることが好ましい。
　海島型複合繊維を溶融紡糸してウェブを得る方法としては、スパンボンド法により紡糸し、海島型複合繊維をカットせずにネット上に捕集して長繊維のウェブを得る方法や、溶融紡糸された海島型複合繊維を捲縮及びカットして得られた海島型複合繊維の短繊維をカーディングして短繊維のウェブを得る方法等が挙げられる。これらの中でも、機械的強度、絡合状態の調整のし易さ、柔軟性、及び弾力性等の観点から、スパンボンド法により紡糸し、海島型複合繊維をカットせずにネット上に捕集して長繊維のウェブを形成する方法（以下、「長繊維のウェブを形成する方法」と称すことがある。）が好ましい。
　なお、本明細書において、スパンボンド法とは、多数のノズル孔が所定のパターンで配置された複合紡糸用口金を用い、海島型複合繊維の溶融ストランドを紡糸ノズルから所定の吐出速度で連続的に複合紡糸用口金から吐出させ、高速気流を用いて冷却しながら延伸させてコンベヤベルト状の移動式のネット上に堆積させる方法を指す。
　スパンボンド法により形成された長繊維のウェブには、その形態安定性を付与するために融着処理が施されてもよい。以下、長繊維のウェブを形成する方法の詳細について説明する。 <Step 1>
Step 1 is a step of obtaining a web.
In this embodiment, from the viewpoint of obtaining napped artificial leather that suppresses the occurrence of color unevenness and has high mechanical strength and excellent texture, the process of obtaining the web involves melt-spinning sea-island composite fibers to form the web. It is preferable to obtain
Methods for obtaining a web by melt-spinning sea-island composite fibers include a method in which the sea-island composite fibers are spun using a spunbond method and then collected on a net without being cut to obtain a web of long fibers; Examples include a method of crimping and cutting the sea-island composite fibers obtained by carding the short fibers of the sea-island composite fibers to obtain a web of short fibers. Among these, from the viewpoints of mechanical strength, ease of adjusting the entangled state, flexibility, and elasticity, spunbond method is used to spin the sea-island composite fibers, which are collected on a net without cutting. A method of forming a web of long fibers (hereinafter sometimes referred to as "a method of forming a web of long fibers") is preferred.
In this specification, the spunbond method refers to a method in which a molten strand of sea-island composite fiber is continuously ejected from a spinning nozzle at a predetermined speed using a composite spinning nozzle in which a large number of nozzle holes are arranged in a predetermined pattern. This refers to a method in which the material is discharged from a composite spinning nozzle, stretched while being cooled using high-speed airflow, and deposited on a moving net in the form of a conveyor belt.
The web of long fibers formed by the spunbond method may be subjected to a fusing treatment in order to impart stability to its shape. The details of the method for forming a web of long fibers will be described below.
　長繊維のウェブを形成するためには、溶融紡糸前及び極細繊維化する前の海島型複合繊維の繊維長は１００ｍｍ以上であることが好ましく、技術的に製造可能であり、かつ、製造工程において不可避的に切断されない限り、数ｍ、数百ｍ、数ｋｍあるいはそれ以上の繊維長であってもよい。なお、後の工程である、絡合処理時のニードルパンチや、バフィング処理工程において、不可避的に長繊維の一部が切断されて短繊維になることもある。 In order to form a web of long fibers, it is preferable that the fiber length of the sea-island composite fibers before melt spinning and before being made into ultra-fine fibers is 100 mm or more. The fiber length may be several meters, several hundred meters, several kilometers, or more, as long as it is not unavoidably cut. In addition, in the subsequent steps of needle punching during entanglement treatment and buffing treatment, some of the long fibers may be unavoidably cut and become short fibers.
　海島型複合繊維に含まれ、後に極細繊維となる島成分の樹脂としては、上述の「極細繊維」における極細繊維を構成する樹脂と同様の樹脂が挙げられる。
　海島型複合繊維に含まれ、抽出や分解すること等により除去される海成分の樹脂としては、島成分の樹脂と溶解性または分解性が異なり、かつ、相溶性の低い樹脂を用いることが好ましい。このような樹脂は、島成分の樹脂の種類や製造方法に応じて適宜選択されることが好ましい。
　海成分の樹脂としては、例えば、ポリエチレン、ポリプロピレン、エチレンプロピレン共重合体、エチレン酢ビ共重合体等のオレフィン系樹脂やポリスチレン、スチレンアクリル共重合体、スチレンエチレン共重合体等の有機溶剤に溶解性があり、有機溶剤により溶解除去できる樹脂や、水溶性ポリビニルアルコール等の水溶性樹脂が挙げられる。これらの中でも、有機溶剤により溶解除去できる樹脂が、固有粘度の高い島成分の樹脂を溶融紡糸できる観点から好ましく、ポリエチレンがより好ましい。 Examples of the island component resin included in the sea-island type composite fiber and which later becomes ultrafine fibers include the same resins as those constituting the ultrafine fibers in the above-mentioned "ultrafine fibers."
As the sea component resin contained in the sea-island composite fiber and removed by extraction or decomposition, it is preferable to use a resin that has a different solubility or degradability from the island component resin and has low compatibility. . It is preferable that such a resin is appropriately selected depending on the type of resin of the island component and the manufacturing method.
Sea component resins include, for example, olefin resins such as polyethylene, polypropylene, ethylene propylene copolymer, and ethylene vinyl acetate copolymer, and polystyrene, styrene-acrylic copolymer, and styrene-ethylene copolymer dissolved in organic solvents. Examples of the resin include resins that have properties and can be dissolved and removed with organic solvents, and water-soluble resins such as water-soluble polyvinyl alcohol. Among these, resins that can be dissolved and removed with organic solvents are preferred from the viewpoint of melt-spinning island component resins with high intrinsic viscosity, and polyethylene is more preferred.
　海島型複合繊維に含まれる海成分と島成分との質量比（海成分／島成分）は、機械的強度の観点から、好ましくは１０／９０～６０／４０、より好ましくは２０／８０～５０／５０である。 The mass ratio of the sea component to the island component (sea component/island component) contained in the sea-island type composite fiber is preferably 10/90 to 60/40, more preferably 20/80 to 50 from the viewpoint of mechanical strength. /50.
　溶融紡糸する際の海島型複合繊維の断面における、後に極細繊維となる島成分の個数は、適度な空隙を有する極細繊維の繊維束を形成する観点から、好ましくは５～２００本、より好ましくは１０～５０本、さらに好ましくは１０～３０本である。 The number of island components that later become ultrafine fibers in the cross section of the sea-island composite fiber during melt spinning is preferably 5 to 200, more preferably 5 to 200, from the viewpoint of forming a fiber bundle of ultrafine fibers with appropriate voids. The number is 10 to 50, more preferably 10 to 30.
　海島型複合繊維は、必要に応じて、例えば、カーボンブラック等の濃色顔料、亜鉛華、鉛白、リトポン、二酸化チタン、沈降性硫酸バリウム及びバライト粉等の白色顔料、耐候剤、防黴剤、加水分解防止剤、滑剤、微粒子、摩擦抵抗調整剤等を本発明の効果を損なわない範囲で含んでもよい。 The sea-island type composite fibers may be prepared with, for example, dark pigments such as carbon black, white pigments such as zinc white, lead white, lithopone, titanium dioxide, precipitated barium sulfate, and barite powder, weathering agents, and antifungal agents. , hydrolysis inhibitors, lubricants, fine particles, frictional resistance modifiers, etc., may be contained within the range that does not impair the effects of the present invention.
　海島型複合繊維を溶融紡糸して得られたウェブは、６０～１５０℃程度の温水に浸漬する収縮処理を行うことにより、ウェブの絡合状態を予め緻密にしてもよい。 The web obtained by melt-spinning the sea-island composite fibers may be subjected to shrinkage treatment by immersing it in hot water of about 60 to 150°C to make the entangled state of the web dense in advance.
＜工程２＞
　工程２は、ウェブに絡合処理をして絡合ウェブを得る工程である。
　工程２は、工程１で得られたウェブを、複数層重ね合わせた後、ニードルパンチや水流交絡処理等による絡合処理を施すことにより、厚み方向に長繊維が絡合された絡合ウェブを得る工程である。重ね合わせるウェブの層数は特に限定されないが、機械的強度の観点から、好ましくは４層以上、より好ましくは８層以上であり、製造容易性の観点から、好ましくは２０層以下、より好ましくは１６層以下である。 <Step 2>
Step 2 is a step of subjecting the web to an entanglement treatment to obtain an entangled web.
In step 2, the web obtained in step 1 is laminated in multiple layers and then subjected to an entangling treatment such as needle punching or hydroentangling treatment to form an entangled web in which long fibers are entangled in the thickness direction. This is the process of obtaining The number of layers of webs to be stacked is not particularly limited, but from the viewpoint of mechanical strength, it is preferably 4 or more layers, more preferably 8 or more layers, and from the viewpoint of ease of manufacture, preferably 20 or less layers, more preferably It has 16 layers or less.
　絡合処理としてニードルパンチを用いる場合、用いるフェルト針の種類は特に限定されないが、厚さ方向への繊維の交絡を充分に高め、機械的強度に優れる人工皮革を得る観点から、細いフェルト針や、１バーブ針等、バーブの数が少ないフェルト針を用いることが好ましい。また、フェルト針は、繊維の切断を抑制する観点からは、バーブ数は３以上が好ましく、より好ましくは５以上、さらに好ましくは６である。
　また、ニードルパンチで用いるフェルト針の単位面積当たりの本数は、特に限定されないが、２００～５５００本／ｃｍ２であることが好ましい。特に、機械的強度を高め、表面に存在する繊維の並びを縦方向に配向させて、表面の高分子弾性体の面積比率を本発明の所定の範囲に低減する観点から、１５００～５０００本／ｃｍ２であることが好ましい。 When needle punching is used for the entangling process, the type of felt needle used is not particularly limited, but from the viewpoint of sufficiently increasing the intertwining of fibers in the thickness direction and obtaining artificial leather with excellent mechanical strength, thin felt needles or It is preferable to use a felting needle with a small number of barbs, such as a one-barb needle. Further, from the viewpoint of suppressing cutting of fibers, the number of barbs in the felt needle is preferably 3 or more, more preferably 5 or more, and still more preferably 6.
Further, the number of felt needles used in the needle punch per unit area is not particularly limited, but is preferably 200 to 5,500 needles/cm 2 . In particular, from the viewpoint of increasing the mechanical strength, orienting the fibers present on the surface in the longitudinal direction, and reducing the area ratio of the polymer elastic body on the surface to the predetermined range of the present invention, 1500 to 5000 fibers/ cm2 is preferred.
　海島型複合繊維の紡糸から絡合処理までのいずれかの段階において、ウェブや絡合ウェブに油剤や帯電防止剤を付与してもよい。 An oil agent or an antistatic agent may be applied to the web or the entangled web at any stage from the spinning of the sea-island composite fiber to the entanglement treatment.
　絡合ウェブの目付としては、高い機械的強度及び優れた風合いを兼ね備えた立毛人工皮革を得る観点から、１００～２０００ｇ／ｍ２であることが好ましい。
　また、絡合ウェブの繊維密度及び絡合度をより向上させる観点から、熱収縮処理を施してもよい。
　また、熱収縮処理により緻密化された絡合ウェブをさらに緻密化するとともに、絡合ウェブの形態を固定化し、表面をより平滑化する等を目的として、例えば、表面温度が１００～１５０℃の熱ロールでプレスしたり、絡合ウェブ中の繊維（島成分）を構成する樹脂の軟化点以上に加熱し、表面温度が該樹脂の軟化点以下である冷却ロールを用いてプレスしてもよい。特に、表面をより平滑化する観点から、冷却ロールの表面温度は、前記樹脂の軟化点より３０℃以上低いことが好ましい。 The basis weight of the entangled web is preferably 100 to 2000 g/m 2 from the viewpoint of obtaining napped artificial leather having both high mechanical strength and excellent texture.
Further, from the viewpoint of further improving the fiber density and degree of entanglement of the entangled web, heat shrinkage treatment may be performed.
In addition, in order to further densify the entangled web that has been densified by heat shrinkage treatment, fix the form of the entangled web, and smoothen the surface, for example, when the surface temperature is 100 to 150 °C It may be pressed with hot rolls, or heated above the softening point of the resin constituting the fibers (island components) in the entangled web, and pressed using cooling rolls whose surface temperature is below the softening point of the resin. . In particular, from the viewpoint of smoothing the surface, the surface temperature of the cooling roll is preferably 30° C. or more lower than the softening point of the resin.
＜工程３＞
　工程３は、絡合ウェブに高分子弾性体を含浸付与して、高分子弾性体を含有する絡合ウェブを得る工程である。
　本実施形態の立毛人工皮革の製造方法おいては、形態安定性、柔軟性、及び弾力性に優れる立毛人工皮革を得る観点から、海成分を除去する前に、高分子弾性体が含浸付与されることが好ましい。
　このように、海成分を除去する前に、高分子弾性体を含浸付与することにより、海成分の除去後に繊維束を形成する極細繊維の間に、海成分を除去して形成される空隙が形成される。その結果、繊維束内部の極細繊維が高分子弾性体に拘束され難くなり、すなわち極細繊維が高分子弾性体の影響を受け難くなり、優れた柔軟性を有する立毛人工皮革が得られる。 <Step 3>
Step 3 is a step of impregnating the entangled web with an elastic polymer to obtain an entangled web containing the elastic polymer.
In the method for producing napped artificial leather of the present embodiment, from the viewpoint of obtaining napped artificial leather with excellent shape stability, flexibility, and elasticity, an elastomer is impregnated with a polymeric elastomer before removing the sea component. It is preferable that
In this way, by impregnating and applying a polymeric elastic material before removing the sea component, the voids formed by removing the sea component can be created between the ultrafine fibers that form the fiber bundle after the sea component is removed. It is formed. As a result, the ultrafine fibers inside the fiber bundle are less likely to be restrained by the elastic polymer, that is, the ultrafine fibers are less likely to be affected by the elastic polymer, and a napped artificial leather with excellent flexibility can be obtained.
　工程３では、高分子弾性体を含むエマルジョンまたは溶液を用いて、絡合ウェブに高分子弾性体を含浸させた後、高分子弾性体を凝固させ、高分子弾性体を含有する絡合ウェブを得る。高分子弾性体が凝固することにより、絡合ウェブの繊維の空隙に高分子弾性体を付与することができる。 In step 3, the entangled web is impregnated with the elastic polymer using an emulsion or solution containing the elastic polymer, and then the elastic polymer is coagulated to form the entangled web containing the elastic polymer. obtain. By solidifying the polymeric elastic material, the polymeric elastic material can be applied to the voids of the fibers of the entangled web.
　高分子弾性体を含むエマルジョンや溶液を用いて絡合ウェブに高分子弾性体を含浸させる方法は、特に限定されないが、ディップニップ法により含浸させる方法が好ましい。 The method of impregnating the entangled web with the polymer elastomer using an emulsion or solution containing the polymer elastomer is not particularly limited, but a dip-nip method is preferred.
　高分子弾性体としては、上述の＜高分子弾性体＞に記載したものが挙げられ、ポリウレタン系樹脂であることが好ましい。
　また、高分子弾性体を含浸付与させる際、高分子弾性体を含む溶液を用いることが好ましく、ポリウレタン系樹脂をＮ，Ｎ-ジメチルホルムアミド（ＤＭＦ）等の溶媒に溶解させた溶剤系ポリウレタンを用いて、高分子弾性体を含有する絡合ウェブ得ることがより好ましい。このように高分子弾性体を含む溶液や、特に溶剤系ポリウレタンを用いることで、高分子弾性体であるポリウレタンと極細繊維とを適度に離型させて柔軟な風合いを有する立毛人工皮革が得られ易くなる。 Examples of the elastic polymer include those described in <Elastic Polymer> above, and polyurethane resins are preferred.
In addition, when impregnating and imparting the polymeric elastomer, it is preferable to use a solution containing the polymeric elastomer, and use a solvent-based polyurethane in which a polyurethane resin is dissolved in a solvent such as N,N-dimethylformamide (DMF). It is more preferable to obtain an entangled web containing an elastomer polymer. In this way, by using a solution containing a polymeric elastomer, or especially a solvent-based polyurethane, it is possible to appropriately release the polyurethane, which is a polymeric elastomer, from the ultrafine fibers, and obtain napped artificial leather with a flexible texture. It becomes easier.
　立毛面に存在する高分子弾性体の面積比率を１７％以下とするために、高分子弾性体を含浸付与する前に、絡合ウェブを前処理してもよく、また、高分子弾性体を含浸付与した後、絡合ウェブから高分子弾性体を選択的に除去してもよい。
　絡合ウェブの前処理としては、例えば、ポリビニルアルコール等の熱可塑性樹脂を塗布または含浸させる方法や、該熱可塑性樹脂をグラビアコーター法、ナイフコーター法、パイプコーター法、コンマコーター法等により、絡合ウェブ表面や、絡合ウェブ中に存在させる方法が挙げられる。
　高分子弾性体を選択的に除去する方法としては、例えば、ニップロール、スクイズバー、ドクターナイフ等により、絡合ウェブ表面に接圧を加えて高分子弾性体を除去する方法が挙げられる。
　本実施形態においては、高分子弾性体の含有量を立毛人工皮革中１５～３５質量％となるように高分子弾性体を絡合ウェブに含浸付与し、高分子弾性体を含有する絡合ウェブを得た後、立毛面に存在する前記高分子弾性体の面積比率が１７％以下となるように、絡合ウェブから高分子弾性体を選択的に除去することが好ましい。 In order to keep the area ratio of the polymeric elastic material present on the raised surface to 17% or less, the entangled web may be pretreated before being impregnated with the polymeric elastic material. After impregnation, the polymeric elastomer may be selectively removed from the entangled web.
Pretreatment of the entangled web includes, for example, a method of coating or impregnating a thermoplastic resin such as polyvinyl alcohol, or a method of coating or impregnating the thermoplastic resin with a gravure coater method, a knife coater method, a pipe coater method, a comma coater method, etc. Examples include a method in which it is present on the surface of an intertwined web or in an intertwined web.
Examples of a method for selectively removing the elastic polymer include a method in which the elastic polymer is removed by applying contact pressure to the surface of the entangled web using a nip roll, a squeeze bar, a doctor knife, or the like.
In this embodiment, the entangled web is impregnated with the polymeric elastic material so that the content of the polymeric elastic material is 15 to 35% by mass in the napped artificial leather, and the entangled web containing the polymeric elastic material is After obtaining the web, it is preferable to selectively remove the elastic polymer from the entangled web so that the area ratio of the elastic polymer present on the napped surface is 17% or less.
　高分子弾性体を凝固させる方法としては、例えば、エマルジョンや溶液に含まれていた水を乾燥除去して凝固させる方法、湿式凝固させる方法等が挙げられる。
　乾燥除去して凝固させる方法としては、５０～２００℃の乾燥装置中で熱処理する方法や、赤外線加熱の後に乾燥機中で熱処理する方法、スチーム処理した後に乾燥機で熱処理する方法、或いは、超音波加熱の後に乾燥機で熱処理する方法、並びに、これらを組み合わせた方法等が挙げられる。 Examples of methods for coagulating the polymeric elastomer include a method of drying and removing water contained in an emulsion or solution and coagulating it, a method of wet coagulation, and the like.
Methods for drying and solidifying include heat treatment in a dryer at 50 to 200°C, infrared heating followed by heat treatment in a dryer, steam treatment followed by heat treatment in a dryer, or ultra-high heat treatment in a dryer. Examples include a method in which heat treatment is performed using a dryer after sonic heating, and a method in which these methods are combined.
　湿式凝固させる方法としては、高分子弾性体を含有する絡合体ウェブを高分子弾性体の貧溶剤を含む処理浴中に浸漬し、高分子弾性体を多孔質状に凝固させる。高分子弾性体の貧溶剤としては水が好ましく用いられるが、例えば高分子弾性体としてポリウレタン系樹脂を用いた場合は、水にジメチルホルムアミド（ＤＭＦ）等の高分子弾性体の良溶剤を混合した処理浴を用いると、その混合比率を適宜設定することにより凝固状態、すなわち多数形成される空孔の大きさ、数や形状などの制御が可能なので好ましい。
　高分子弾性体を含むエマルジョンを用いて高分子弾性体を付与した場合、感熱ゲル化剤を添加しておくと、乾式法、あるいはこれにスチーミングや遠赤外加熱などの方法を組み合わせることで厚み方向により均一な凝固が可能である。
　また、有機溶剤と高分子弾性体を含む溶液を用いて高分子弾性体を付与した場合、凝固調整剤を併用することで、より均一な空孔を得ることができる。また、前記有機溶剤の例としては、ジメチルホルムアミド、ジメチルアセトアミド、ジメチルスルホキシド等が挙げられる。絡合ウェブが含有する高分子弾性体を多孔質状に凝固させることにより、天然皮革に類似した風合いを得ることができる。
　これらの中でも、湿式凝固させる方法が好ましく、水に有機溶剤としてジメチルホルムアミドを混合した処理液中に絡合ウェブを浸漬して凝固させる方法がより好ましい。 In the wet coagulation method, the entangled web containing the elastomer polymer is immersed in a treatment bath containing a poor solvent for the elastomer polymer, and the elastomer polymer is coagulated into a porous state. Water is preferably used as a poor solvent for the polymeric elastomer, but for example, when polyurethane resin is used as the polymeric elastomer, a good solvent for the polymeric elastomer such as dimethylformamide (DMF) is mixed with water. It is preferable to use a treatment bath because it is possible to control the solidification state, that is, the size, number, shape, etc. of the large number of pores formed, by appropriately setting the mixing ratio.
When applying a polymer elastomer using an emulsion containing a polymer elastomer, if a heat-sensitive gelling agent is added, it is possible to use a dry method or a combination of methods such as steaming or far-infrared heating. More uniform solidification is possible in the thickness direction.
Furthermore, when an elastic polymer is applied using a solution containing an organic solvent and an elastic polymer, more uniform pores can be obtained by using a coagulation modifier in combination. Furthermore, examples of the organic solvent include dimethylformamide, dimethylacetamide, dimethylsulfoxide, and the like. By coagulating the polymer elastic body contained in the entangled web into a porous state, a texture similar to that of natural leather can be obtained.
Among these, a method of wet coagulation is preferable, and a method of coagulating the entangled web by immersing it in a treatment solution of water mixed with dimethylformamide as an organic solvent is more preferable.
＜工程４＞
　工程４は、高分子弾性体を含有する絡合ウェブから、海成分を除去する工程である。海成分を除去することにより、極細化可能繊維を極細繊維の繊維束に変換する。すなわち、絡合ウェブ中の繊維が極細繊維化され、極細繊維と、高分子弾性体とを含有する不織布（以下、高分子弾性体を含有する不織布と称すことがある。）が得られる。 <Step 4>
Step 4 is a step of removing sea components from the entangled web containing the elastomer polymer. By removing the sea component, the microfibers are converted into fiber bundles of microfibers. That is, the fibers in the entangled web are made into ultrafine fibers, and a nonwoven fabric containing ultrafine fibers and an elastic polymer (hereinafter sometimes referred to as a nonwoven fabric containing an elastic polymer) is obtained.
　海成分の樹脂を除去する方法としては、例えば、海成分の樹脂のみを選択的に除去し得る溶剤または分解剤を用いて除去する方法が挙げられる。
　本実施形態においては、固有粘度の高い島成分の樹脂を溶融紡糸できる観点からポリエチレンの使用が好ましく、この点から有機溶剤で海成分を溶解除去することが好ましい。
　海成分を溶解除去する有機溶剤としては、島成分の樹脂がポリアミド系樹脂やポリエステル系樹脂であり、海成分の樹脂がポリエチレンである場合、トルエン、トリクロロエチレン、テトラクロロエチレン等が挙げられる。 Examples of the method for removing the sea component resin include a method using a solvent or a decomposing agent that can selectively remove only the sea component resin.
In this embodiment, it is preferable to use polyethylene from the viewpoint of melt-spinning the resin of the island component having a high intrinsic viscosity, and from this point of view, it is preferable to dissolve and remove the sea component with an organic solvent.
Examples of the organic solvent for dissolving and removing the sea component include toluene, trichlorethylene, tetrachloroethylene, etc. when the resin of the island component is a polyamide resin or polyester resin and the resin of the sea component is polyethylene.
　海成分を除去する際、ディップニップ処理を並行して行うことが好ましい。
　また、海島型複合繊維を溶融紡糸してウェブを得てから海成分を除去するまでの間に、水蒸気、熱水、乾熱等、熱収縮処理（繊維収縮処理）を施して繊維を緻密化させてもよい。 When removing the sea component, it is preferable to perform dip nip treatment in parallel.
In addition, after the sea-island composite fibers are melt-spun to obtain a web and before the sea component is removed, the fibers are densified by applying heat shrinkage treatment (fiber shrinkage treatment) using steam, hot water, dry heat, etc. You may let them.
　高分子弾性体を含有する不織布は、海成分の樹脂を除去した後、乾燥することが好ましい。５０～２００℃の乾燥装置中で熱処理する方法や、赤外線加熱の後に乾燥機中で熱処理する方法、スチーム処理した後に乾燥機で熱処理する方法、或いは、超音波加熱の後に乾燥機で熱処理する方法、並びに、これらを組み合わせた方法等が挙げられる。
　また、高分子弾性体を含有する不織布は、必要に応じて、所定の厚さに切断してもよい。
　また、高分子弾性体を含有する不織布の目付は、機械的強度の観点から、好ましくは１４０～３０００ｇ／ｍ2、より好ましくは２００～２０００ｇ／ｍ2である。 It is preferable that the nonwoven fabric containing the polymeric elastomer is dried after removing the sea component resin. A method of heat treatment in a dryer at 50 to 200°C, a method of heat treatment in a dryer after infrared heating, a method of heat treatment in a dryer after steam treatment, or a method of heat treatment in a dryer after ultrasonic heating. , and methods that combine these methods.
Further, the nonwoven fabric containing the polymer elastic body may be cut to a predetermined thickness, if necessary.
In addition, the basis weight of the nonwoven fabric containing the polymeric elastic material is preferably 140 to 3000 g/m 2 , more preferably 200 to 2000 g/m 2 from the viewpoint of mechanical strength.
＜工程５＞
　工程５は、工程４で得られた高分子弾性体を含有する不織布を、バフィング処理する工程である。
　高分子弾性体を含有する不織布の片面または両面をバフィング処理することにより、前記不織布の表面に存在する繊維が立毛され、立毛面を有する立毛人工皮革が得られる。バフィング処理は、好ましくは１２０～６００番手、より好ましくは３２０～６００番手のサンドペーパーやエメリーペーパーを用いて行われる。このようにして、片面または両面に立毛面を有する立毛人工皮革が得られる。サンドペーパー番手、エメリーペーパー番手、ペーパーの回転数、接触長、接触圧力等を適宜調整することにより、立毛繊維長を調整することができ、ペーパー回転数、接触長、接触圧力を高くすると、立毛繊維長を短くすることができる。 <Step 5>
Step 5 is a step of buffing the nonwoven fabric containing the polymer elastic body obtained in Step 4.
By buffing one or both sides of a nonwoven fabric containing a polymeric elastomer, the fibers present on the surface of the nonwoven fabric are napped, and napped artificial leather having a napped surface is obtained. The buffing process is preferably carried out using sandpaper or emery paper of 120 to 600 grit, more preferably 320 to 600 grit. In this way, napped artificial leather having napped surfaces on one or both sides can be obtained. By appropriately adjusting the sandpaper count, emery paper count, paper rotation speed, contact length, contact pressure, etc., the napped fiber length can be adjusted. Fiber length can be shortened.
　立毛人工皮革は、さらに風合いを向上させるために、柔軟性を付与する収縮加工処理、揉み柔軟化処理、逆シールのブラッシング処理、防汚処理、親水化処理、滑剤処理、柔軟剤処理、酸化防止剤処理、紫外線吸収剤処理、蛍光剤処理、難燃処理等の仕上げ処理が施されてもよい。 In order to further improve the texture, raised artificial leather is subjected to shrinkage processing to add flexibility, kneading to soften it, brushing for reverse sealing, antifouling treatment, hydrophilic treatment, lubricant treatment, softener treatment, and anti-oxidation treatment. Finishing treatments such as agent treatment, ultraviolet absorber treatment, fluorescent agent treatment, and flame retardant treatment may be performed.
　本実施形態における立毛人工皮革は着色可能であり、染料や顔料を用いて着色することが好ましい。固着させるため樹脂などと併用する必要があり、風合いが硬化しやすい顔料に対し、繊維中に入り込むため樹脂の併用が不要で風合い低下懸念が少なく、かつ染料の種類や濃度調整で簡便に様々な色に着色しやすい観点から、染料を用いて染色することが好ましい。
　染料としては、例えば、極細繊維がポリエステル系樹脂から形成されている場合には、分散染料やカチオン染料で染色することが好ましい。分散染料の具体例としては、例えば、ベンゼンアゾ系染料（モノアゾ、ジスアゾ等）、複素環アゾ系染料（チアゾールアゾ、ベンゾチアゾールアゾ、キノリンアゾ、ピリジンアゾ、イミダゾールアゾ、チオフェンアゾ等）、アントラキノン系染料、縮合系染料（キノフタリン、スチリル、クマリン等）等が挙げられる。これらは、例えば、「Ｄｉｓｐｅｒｓｅ」の接頭辞を有する染料として市販されている。これらは、単独で用いても２種以上を組み合わせて用いてもよい。また、染色方法としては、高圧液流染色法、ジッガー染色法、サーモゾル連続染色機法、昇華プリント方式等による染色方法を用いることができる。 The napped artificial leather in this embodiment can be colored, and is preferably colored using a dye or a pigment. Unlike pigments, which need to be used in combination with resins to make them stick, and whose texture tends to harden, pigments penetrate into the fibers, so there is no need to use resins in combination, there is less concern about deterioration of texture, and it is easy to create a variety of colors by adjusting the type and concentration of the dye. From the viewpoint of easy coloring, it is preferable to dye using a dye.
As the dye, for example, when the ultrafine fiber is formed from a polyester resin, it is preferable to dye it with a disperse dye or a cationic dye. Specific examples of disperse dyes include benzene azo dyes (monoazo, disazo, etc.), heterocyclic azo dyes (thiazole azo, benzothiazo azo, quinoline azo, pyridine azo, imidazole azo, thiophene azo, etc.), anthraquinone dyes, and condensed dyes. Examples include dyes such as quinophthalin, styryl, coumarin, etc. These are, for example, commercially available as dyes with the prefix "Disperse". These may be used alone or in combination of two or more. Further, as a dyeing method, a dyeing method such as a high-pressure jet dyeing method, a jigger dyeing method, a thermosol continuous dyeing method, a sublimation printing method, etc. can be used.
　以下、実施例及び比較例を用いて本発明をより詳細に説明するが、本発明は下記実施例に限定されるものではない。 Hereinafter, the present invention will be explained in more detail using Examples and Comparative Examples, but the present invention is not limited to the Examples below.
［評価］
＜平均繊度＞
　立毛人工皮革を厚み方向に切断し、その断面を走査型電子顕微鏡（ＳＥＭ）（株式会社日立製作所製　Ｓ－３０００Ｎ）を用いて３０００倍で撮影した。得られた画像から、極細繊維をランダムに１５個選び、その断面積を測定した。続いて、その断面積の平均値（１５個の平均値）を算出し、断面積の平均値と極細繊維を構成する樹脂の密度から平均繊度を求めた。 [evaluation]
<Average fineness>
The napped artificial leather was cut in the thickness direction, and the cross section was photographed at 3000x using a scanning electron microscope (SEM) (S-3000N manufactured by Hitachi, Ltd.). From the obtained images, 15 ultrafine fibers were randomly selected and their cross-sectional areas were measured. Subsequently, the average value of the cross-sectional area (15 average values) was calculated, and the average fineness was determined from the average value of the cross-sectional area and the density of the resin constituting the ultrafine fiber.
＜立毛繊維長＞
　立毛人工皮革を厚み方向に切断し、立毛人工皮革の立毛面に存在する立毛繊維を、整毛ブラシ等を用いて逆目に揃えた後、立毛人工皮革の断面を走査型電子顕微鏡（ＳＥＭ）で倍率４０倍にて撮影した。得られた画像において、不織布中の極細繊維の根本、または高分子弾性体皮膜を形成している場合は、高分子弾性体皮膜が存在する上限に、線Ｌ１を引き、観察面の最も手前の繊維が立毛している上限に線Ｌ２を引いた。さらに２００μｍ間隔で立毛人工皮革表面と垂直な方向に線Ｌ３を複数本引いた。
　線Ｌ３における線Ｌ１から線Ｌ２までの長さを１０本分測定し、それらの算術平均値を求めた。
　上記について、立毛人工皮革の任意に選択した１０箇所で実施した。得られた１０箇所の算術平均値をさらに算術平均し、小数点以下第１位を四捨五入した値を、立毛繊維長（μｍ）とした。
　立毛人工皮革の立毛繊維長の測定方法を説明する概念図を図３に示す。 <Nap-pilled fiber length>
After cutting the napped artificial leather in the thickness direction and aligning the napped fibers present on the napped side of the napped artificial leather in the opposite direction using a hair straightening brush, the cross section of the napped artificial leather was examined using a scanning electron microscope (SEM). Photographed at 40x magnification. In the obtained image, draw a line L1 at the root of the ultrafine fibers in the nonwoven fabric, or at the upper limit where the polymeric elastic film is present if an elastic polymeric film exists, and draw the line L1 at the point closest to the observation surface. A line L2 was drawn at the upper limit where the fibers were raised. Furthermore, a plurality of lines L3 were drawn at 200 μm intervals in a direction perpendicular to the surface of the napped artificial leather.
Ten lengths from the line L1 to the line L2 in the line L3 were measured, and the arithmetic mean value was calculated.
The above was carried out at 10 arbitrarily selected locations on the napped artificial leather. The obtained arithmetic mean values at 10 locations were further arithmetic averaged, and the value rounded to the first decimal place was defined as the napped fiber length (μm).
A conceptual diagram illustrating a method for measuring the napped fiber length of napped artificial leather is shown in FIG. 3.
＜高分子弾性体の含有量＞
　立毛人工皮革から小片を切り出し、その重量（Ｗ１）を測定した。その小片をジメチルホルムアミドに１２時間浸漬後プレス処理を行い、その後さらにジメチルホルムアミドに５分間浸漬後プレス処理を行う動作を５回繰り返し、高分子弾性体を抽出した。そして、高分子弾性体抽出後の不織布の乾燥を行い、乾燥後の不織布の重量（Ｗ２）を測定した。そして、高分子弾性体の含有量（Ｂ）を下記式から算出した。
（Ｂ）＝（Ｗ１－Ｗ２）／Ｗ１×１００　（質量％） <Content of polymer elastic body>
A small piece was cut out from the napped artificial leather, and its weight (W1) was measured. The small piece was immersed in dimethylformamide for 12 hours and then subjected to a press treatment, and then further immersed in dimethylformamide for 5 minutes and then subjected to a press treatment, which was repeated 5 times to extract the polymer elastomer. Then, the nonwoven fabric after the polymer elastomer extraction was dried, and the weight (W2) of the dried nonwoven fabric was measured. Then, the content (B) of the polymer elastic body was calculated from the following formula.
(B)=(W1-W2)/W1×100 (mass%)
＜高分子弾性体の面積比率＞
　立毛人工皮革の立毛面を、走査型電子顕微鏡（ＳＥＭ）を用い、倍率５０倍にてそれぞれ異なる箇所を３枚撮影し、得られたそれぞれの画像をＡ４サイズの用紙に印刷した。そして、印刷した用紙をＯＨＰ（Ｏｖｅｒｈｅａｄ　ｐｒｏｊｅｃｔｏｒ）シートに重ね、ＯＨＰシートに高分子弾性体の部位を黒塗りして転写した。高分子弾性体の部位を黒塗りしたＯＨＰシートの模様を、スキャナーで取り込み画像を形成した。
　続いて、画像処理ソフトＩｍａｇｅ-Ｐｒｏ　Ｐｒｅｍｉｅｒ　９．２（ｉｍａｇｅ‐ｐｒｏ　ｐｌｕｓ，Ｍｅｄｉａ　Ｃｙｂｅｒｎｅｔｉｃｓ社製）を用いて、得られた画像における高分子弾性体が存在する領域の総面積を求めた。求めた総面積と画像全領域の総面積から、高分子弾性体の面積比率を下記式により算出した。
　高分子弾性体の面積比率＝高分子弾性体が存在する領域の総面積／画像全領域の総面積×１００（％）
　図１に立毛面を走査型電子顕微鏡（ＳＥＭ）で倍率５０倍にて撮影した画像を、図２に図１の画像の高分子弾性体であるポリウレタン部位をＯＨＰシートに黒塗りして転写した画像を示す。 <Area ratio of elastic polymer>
Three images of the raised surface of the raised artificial leather were taken at 50x magnification using a scanning electron microscope (SEM), and each of the obtained images was printed on A4 size paper. Then, the printed paper was placed on an OHP (overhead projector) sheet, and the portion of the polymeric elastic body was painted black and transferred onto the OHP sheet. A pattern on an OHP sheet in which the portion of the polymeric elastic body was painted black was captured by a scanner and an image was formed.
Subsequently, using image processing software Image-Pro Premier 9.2 (image-pro plus, manufactured by Media Cybernetics), the total area of the region where the polymeric elastic body existed in the obtained image was determined. From the obtained total area and the total area of the entire image area, the area ratio of the polymer elastic body was calculated using the following formula.
Area ratio of elastic polymer = total area of area where elastic polymer exists / total area of entire image area x 100 (%)
Figure 1 is an image of the raised surface taken with a scanning electron microscope (SEM) at a magnification of 50x, and Figure 2 is a transfer of the polyurethane part of the polymeric elastic material from the image in Figure 1 to an OHP sheet by painting it black. Show images.
＜見掛け密度＞
ＪＩＳ　Ｌ　１０９６：２０１０に準じて、厚さ（ｍｍ）及び目付け（ｇ／ｃｍ２）を測定し、これらの値から見掛け密度（ｇ／ｃｍ３）を求めた。 <Apparent density>
The thickness (mm) and basis weight (g/cm 2 ) were measured in accordance with JIS L 1096:2010, and the apparent density (g/cm 3 ) was determined from these values.
＜引張強度＞
　立毛人工皮革から切り出した２．５ｃｍ×１６ｃｍの試験片を用いて、ＪＩＳ　Ｌ１０９６：２０１０　８．１４．１「引張強度試験」に準じて応力－歪み曲線を得た。
　試験片は、立毛人工皮革の縦方向に長尺を沿わせて切り出した試験片３枚と、横方向に長尺を沿わせて切り出した試験片３枚を用いた。
　それぞれの試験片を用いて得られた応力－歪み曲線から、破断した時の応力を読み取り、縦方向に長尺を沿わせて切り出した試験片３枚の応力の平均値と、横方向に長尺を沿わせて切り出した試験片３枚の応力の平均値を算出し、低い方の値（平均値）を引張強度とした。 <Tensile strength>
Using a 2.5 cm x 16 cm test piece cut from napped artificial leather, a stress-strain curve was obtained according to JIS L1096:2010 8.14.1 "Tensile strength test".
The test pieces used were three test pieces cut out along the longitudinal direction of the napped artificial leather and three test pieces cut out along the horizontal direction.
The stress at break is read from the stress-strain curve obtained using each test piece, and the average value of the stress of three test pieces cut along the length in the vertical direction and the long length in the horizontal direction are calculated. The average stress value of three test pieces cut along the length was calculated, and the lower value (average value) was taken as the tensile strength.
＜外観＞
　立毛人工皮革の外観を以下の基準で判定した。
　Ａ：立毛面に存在する高分子弾性体が全く、または極僅かしか視認されず、色ムラが抑制され、発色性にも優れる。
　Ｂ：立毛面に存在する高分子弾性体がムラ状に視認され、色ムラが発生している。 <Exterior>
The appearance of the napped artificial leather was evaluated based on the following criteria.
A: The polymeric elastomer present on the napped surface is not visible at all or only slightly, color unevenness is suppressed, and color development is excellent.
B: The polymeric elastic material present on the raised surface is visible in an uneven manner, and color unevenness occurs.
＜緻密性＞
　立毛人工皮革の緻密性を、目視及び触感により以下の基準で判定した。
　Ａ：立毛が細かく分散した状態で均一な長さを有し、スムースな感触である。
　Ｂ：立毛が粗く分散した状態で不均一な長さを有し、粗い感触でライティングがない。 <Denseness>
The denseness of the napped artificial leather was judged visually and by touch using the following criteria.
A: The fluff is finely dispersed, has a uniform length, and has a smooth feel.
B: The raised naps are coarsely dispersed and have non-uniform lengths, giving a rough feel and no writing.
＜風合い＞
　立毛人工皮革を折り曲げた際の風合いを、目視及び触感により以下の基準で判定した。
　Ａ：柔軟性、弾力性等に優れる。
　Ｂ：柔軟性及び弾力性の少なくとも１つが劣る。 <Texture>
The feel of the napped artificial leather when folded was evaluated visually and by touch using the following criteria.
A: Excellent flexibility, elasticity, etc.
B: At least one of flexibility and elasticity is poor.
（実施例１）
　島成分としてポリエチレンテレフタレート（ＰＥＴ）、海成分としてポリエチレンを準備し、島数が１２島となるような溶融複合用口金を用い、海成分／島成分の質量比が３５／６５となるように圧力調整をして口金温度設定２８０℃、単孔吐出１．２ｇ／ｍｉｎで吐出させ、紡糸速度４０００ｍ／ｍｉｎで繊度３ｄｔｅｘの海島型複合繊維を紡糸した。
　得られた海島型複合繊維を可動型ネット上に連続的に堆積し、表面の毛羽立ちを抑えるために加熱した金属ロールで軽く押さえた。そして、海島型複合繊維をネットから剥離し、加熱した金属ロールとバックロールとの間を押圧下で通過させ、目付４０ｇ／ｍ２の長繊維のウェブを製造した。 (Example 1)
Prepare polyethylene terephthalate (PET) as the island component and polyethylene as the sea component, and use a melting composite nozzle so that the number of islands is 12, and pressurize so that the mass ratio of the sea component/island component is 35/65. After adjustment, the spinneret temperature was set at 280° C., single-hole discharge was performed at 1.2 g/min, and sea-island composite fibers with a fineness of 3 dtex were spun at a spinning speed of 4000 m/min.
The obtained sea-island composite fibers were continuously deposited on a movable net and lightly pressed with a heated metal roll to prevent surface fluffing. The sea-island composite fibers were then peeled from the net and passed between a heated metal roll and a back roll under pressure to produce a web of long fibers with a basis weight of 40 g/m 2 .
　得られたウェブを１２枚積層し、積層ウェブを形成した。そして、積層ウェブに対して６バーブのニードル針を用いて２０５０本／ｃｍ２のパンチング密度でニードルパンチ処理を行うことにより、目付け６００ｇ／ｍ２の絡合ウェブを形成した。得られた絡合ウェブを９０℃の熱水で収縮処理を行い、乾燥後、熱プレスすることにより、目付８００ｇ／ｍ２の熱収縮処理された絡合ウェブを得た。 Twelve sheets of the obtained web were laminated to form a laminated web. Then, the laminated web was subjected to needle punching using a 6-barb needle at a punching density of 2050 punches/cm 2 to form an entangled web with a basis weight of 600 g/m 2 . The resulting entangled web was subjected to shrinkage treatment with hot water at 90°C, dried, and then hot pressed to obtain a heat-shrinkable entangled web with a basis weight of 800 g/m 2 .
　続いて、高分子弾性体である１００％モジュラス４．５ＭＰａのポリカーボネート系ポリウレタンのＤＭＦ溶液（固形分１５質量％）に、立毛人工皮革中の高分子弾性体の含有量が１８質量％になるように、熱収縮処理された絡合ウェブを含浸させた。含浸させた後、その絡合ウェブ表面に存在するポリカーボネート系ポリウレタンを、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が５％となるように、接圧を加えて選択的に除去した後、水：ＤＭＦが質量比で７０：３０のＤＭＦ水溶液に浸漬してポリカーボネート系ポリウレタンを凝固させ、絡合ウェブにポリカーボネート系ポリウレタン（ポリウレタン系樹脂）を付与した。 Next, a DMF solution (solid content 15% by mass) of a polycarbonate polyurethane having a 100% modulus of 4.5 MPa, which is a polymeric elastic material, was added so that the content of the polymeric elastic material in the napped artificial leather was 18% by mass. was impregnated with a heat-shrinked entangled web. After impregnation, the polycarbonate polyurethane present on the surface of the entangled web is selectively removed by applying contact pressure so that the area ratio of the polycarbonate polyurethane present on the napped surface is 5%, and then water is applied. :DMF was immersed in a DMF aqueous solution having a mass ratio of 70:30 to coagulate the polycarbonate-based polyurethane, thereby imparting polycarbonate-based polyurethane (polyurethane-based resin) to the entangled web.
　次に、ポリウレタン系樹脂が付与された絡合ウェブを、ニップ処理をしつつ、８５℃のトルエン中に浸漬し、海成分であるポリエチレンを溶解除去した後、乾燥し、ポリエステルの極細繊維を含み、高分子弾性体としてポリウレタン系樹脂が付与された不織布を得た。得られた不織布の目付は６００ｇ／ｍ２であった。 Next, the entangled web to which the polyurethane resin has been applied is dipped in toluene at 85°C while being nipped to dissolve and remove the polyethylene, which is a sea component, and then dried. A nonwoven fabric to which a polyurethane resin was applied as a polymeric elastomer was obtained. The fabric weight of the obtained nonwoven fabric was 600 g/m 2 .
　得られた不織布を、人工皮革生機とするため厚み方向に半裁し、半裁面側を♯１８０、♯２４０のサンドペーパーでバフィング後、さらに、非半裁面を♯３２０、♯６００のサンドペーパーで研削の一方の面をバフィング処理することにより、立毛面を有する立毛人工皮革を得た。
　続いて、得られた立毛人工皮革を、分散染料を染料濃度６％ｏｗｆに調整し、サーキュラー染色機にて１３０℃高圧染色を行い、その後還元洗浄、酸化処理、水洗を行うことにより、着色された立毛人工皮革を得た。着色された立毛人工皮革の評価結果を表１に示す。 The obtained nonwoven fabric was cut in half in the thickness direction to make artificial leather raw material, and the half-cut side was buffed with #180 and #240 sandpaper, and then the non-half-cut side was ground with #320 and #600 sandpaper. A napped artificial leather having a napped surface was obtained by buffing one side of the material.
Next, the obtained raised artificial leather was colored by adjusting the disperse dye to a dye concentration of 6% owf, performing high-pressure dyeing at 130 ° C in a circular dyeing machine, and then performing reduction cleaning, oxidation treatment, and water washing. A raised artificial leather was obtained. Table 1 shows the evaluation results of the colored raised artificial leather.
（実施例２）
　実施例１において、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が５％となるように、接圧を加えて選択的に除去する代わりに、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が９．３％となるように、接圧を加えて選択的に除去したこと以外は同様にして、着色された立毛人工皮革を得た。その評価結果を表１に示す。 (Example 2)
In Example 1, instead of selectively removing by applying contact pressure so that the area ratio of polycarbonate-based polyurethane existing on the raised surface was 5%, the area ratio of polycarbonate-based polyurethane existing on the raised surface was 9%. Colored napped artificial leather was obtained in the same manner, except that it was selectively removed by applying contact pressure so that the concentration was 0.3%. The evaluation results are shown in Table 1.
（実施例３）
　実施例１において、バフィング処理をして０．４ｍｍの立毛人工皮革を得た以外は同様にして、着色された立毛人工皮革を得た。その評価結果を表１に示す。 (Example 3)
Colored napped artificial leather was obtained in the same manner as in Example 1, except that buffing treatment was performed to obtain napped artificial leather of 0.4 mm. The evaluation results are shown in Table 1.
（実施例４）
　実施例１において、高分子弾性体である１００％モジュラス４．５ＭＰａのポリカーボネート系ポリウレタンのＤＭＦ溶液（固形分１５％）に、立毛人工皮革中の高分子弾性体の含有量が１８質量％になるように、熱収縮処理された絡合ウェブを含浸させた代わりに、高分子弾性体である１００％モジュラス４．５ＭＰａのポリカーボネート系ポリウレタンのＤＭＦ溶液（固形分１８．５％）に、立毛人工皮革中の高分子弾性体の含有量が３２質量％になるように、熱収縮処理された絡合ウェブを含浸させたこと以外は同様にして、着色された立毛人工皮革を得た。その評価結果を表１に示す。 (Example 4)
In Example 1, a DMF solution (solid content 15%) of polycarbonate polyurethane having a 100% modulus of 4.5 MPa, which is a polymeric elastic material, was added such that the content of the polymeric elastic material in the napped artificial leather was 18% by mass. Instead of impregnating a heat-shrink-treated entangled web, napped artificial leather is impregnated with a DMF solution (solid content 18.5%) of polycarbonate polyurethane, which is a polymeric elastomer and has a 100% modulus of 4.5 MPa. Colored napped artificial leather was obtained in the same manner except that a heat-shrinkable entangled web was impregnated so that the content of the polymeric elastic material therein was 32% by mass. The evaluation results are shown in Table 1.
（実施例５）
　実施例１において、得られた不織布を、人工皮革生機とするため片面側を♯１８０及び♯２４０のサンドペーパーでバフィング後、さらに、非処理面を♯３２０及び♯６００のサンドペーパーで研削の一方の面をバフィング処理することにより、立毛面を有する厚み１．０ｍｍの立毛人工皮革を得たこと以外は同様にして、着色された立毛人工皮革を得た。その評価結果を表１に示す。 (Example 5)
In Example 1, one side of the obtained nonwoven fabric was buffed with #180 and #240 sandpaper in order to make it into an artificial leather raw material, and then the untreated side was ground with #320 and #600 sandpaper. A colored napped artificial leather was obtained in the same manner except that a napped artificial leather having a napped surface and a thickness of 1.0 mm was obtained by buffing the surface. The evaluation results are shown in Table 1.
（実施例６）
　島成分としてポリエチレンテレフタレート（ＰＥＴ）、海成分としてポリエチレンを準備し、島数が１６島となるような溶融複合用口金を用い、海成分／島成分の質量比が３５／６５となるように圧力調整をして口金温度設定２８０℃、単孔吐出１．２ｇ／ｍｉｎで吐出させ、紡糸速度８２０ｍ／ｍｉｎで紡糸した後、延伸、捲縮処理を行い、繊度４．０ｄｔｅｘの短繊維である海島型複合繊維を得た。
　次に、海島型複合繊維をカードへ通過させ、短繊維のウェブを製造した。
　得られたウェブを複数枚積層し、積層ウェブを形成した。そして、積層ウェブに対して１バーブのニードル針を用いて２０５０本／ｃｍ２のパンチング密度でニードルパンチ処理を行うことにより、目付け６００ｇ／ｍ２の絡合ウェブを形成した。得られた絡合ウェブを９０℃の熱水で収縮処理を行い、乾燥後、熱プレスすることにより、目付８００ｇ／ｍ２の熱収縮処理された絡合ウェブを得た。
　続いて、高分子弾性体である１００％モジュラス４．５ＭＰａのポリカーボネート系ポリウレタンのＤＭＦ溶液（固形分１５質量％）に、立毛人工皮革中の高分子弾性体の含有量が１８質量％になるように、熱収縮処理された絡合ウェブを含浸させた。含浸させた後、その絡合ウェブ表面に存在するポリカーボネート系ポリウレタンを、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が５％となるように、接圧を加えて選択的に除去した後、水：ＤＭＦが質量比で７０：３０のＤＭＦ水溶液に浸漬してポリカーボネート系ポリウレタンを凝固させ、絡合ウェブにポリカーボネート系ポリウレタン（ポリウレタン系樹脂）を付与した。
　次に、ポリウレタン系樹脂が付与された絡合ウェブを、ニップ処理をしつつ、８５℃のトルエン中に浸漬し、海成分であるポリエチレンを溶解除去した後、乾燥し、ポリエステルの極細繊維を含み、高分子弾性体としてポリウレタン系樹脂が付与された不織布を得た。得られた不織布の目付は８２０ｇ／ｍ２であった。 (Example 6)
Prepare polyethylene terephthalate (PET) as the island component and polyethylene as the sea component, and use a melting composite nozzle so that the number of islands is 16, and pressurize so that the mass ratio of the sea component/island component is 35/65. After adjusting the nozzle temperature setting to 280°C and discharging at a single hole discharge rate of 1.2 g/min, and spinning at a spinning speed of 820 m/min, stretching and crimping are performed to obtain sea islands, which are short fibers with a fineness of 4.0 dtex. A composite fiber was obtained.
The sea-island composite fibers were then passed through a card to produce a short fiber web.
A plurality of the obtained webs were laminated to form a laminated web. Then, the laminated web was subjected to needle punching using a 1-barb needle at a punching density of 2050 punches/cm 2 to form an entangled web with a basis weight of 600 g/m 2 . The resulting entangled web was subjected to shrinkage treatment with hot water at 90°C, dried, and then hot pressed to obtain a heat-shrinkable entangled web with a basis weight of 800 g/m 2 .
Next, a DMF solution (solid content 15% by mass) of a polycarbonate polyurethane having a 100% modulus of 4.5 MPa, which is a polymeric elastic material, was added so that the content of the polymeric elastic material in the napped artificial leather was 18% by mass. was impregnated with a heat-shrinked entangled web. After impregnation, the polycarbonate polyurethane present on the surface of the entangled web is selectively removed by applying contact pressure so that the area ratio of the polycarbonate polyurethane present on the napped surface is 5%, and then water is applied. :DMF was immersed in a DMF aqueous solution having a mass ratio of 70:30 to coagulate the polycarbonate-based polyurethane, thereby imparting polycarbonate-based polyurethane (polyurethane-based resin) to the entangled web.
Next, the entangled web to which the polyurethane resin has been applied is dipped in toluene at 85°C while being nipped to dissolve and remove the polyethylene, which is a sea component, and then dried. A nonwoven fabric to which a polyurethane resin was applied as a polymeric elastomer was obtained. The fabric weight of the obtained nonwoven fabric was 820 g/m 2 .
（比較例１）
　実施例１において、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が５％となるように、接圧を加えて選択的に除去した代わりに、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が１７．６％となるように、接圧を加えて選択的に除去したこと以外は同様にして、着色された立毛人工皮革を得た。その評価結果を表１に示す。 (Comparative example 1)
In Example 1, instead of selectively removing by applying contact pressure so that the area ratio of the polycarbonate-based polyurethane existing on the raised surface was 5%, the area ratio of the polycarbonate-based polyurethane existing on the raised surface was 17%. Colored napped artificial leather was obtained in the same manner, except that it was selectively removed by applying contact pressure so that the concentration was .6%. The evaluation results are shown in Table 1.
（比較例２）
　実施例１において、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が５％となるように、接圧を加えて選択的に除去した代わりに、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が１４．８％となるように、接圧を加えて選択的に除去したこと、また、バフィング処理を行う際に、立毛繊維長が２５０μｍとなるように調整したこと以外は同様にして、着色された立毛人工皮革を得た。その評価結果を表１に示す。 (Comparative example 2)
In Example 1, instead of selectively removing by applying contact pressure so that the area ratio of polycarbonate-based polyurethane existing on the raised surface was 5%, the area ratio of polycarbonate-based polyurethane existing on the raised surface was 14%. Coloring was carried out in the same manner except that contact pressure was applied to selectively remove the fibers so that the fiber concentration was 8%, and the length of the napped fibers was adjusted to 250 μm during the buffing process. Napped artificial leather was obtained. The evaluation results are shown in Table 1.
（比較例３）
　実施例１において、１００％モジュラス４．５ＭＰａのポリカーボネート系ポリウレタンのＤＭＦ溶液（固形分１５％）の代わりに、含有量が１．０質量％となるようにカーボンブラックが添加・着色された１００％モジュラス４．５ＭＰａのポリカーボネート系ポリウレタンのＤＭＦ溶液（固形分１５％）を用いたこと、また、不織布表面に存在するポリカーボネート系ポリウレタンを、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が５％となるように、接圧を加えて選択的に除去した代わりに、絡合ウェブに存在するポリカーボネート系ポリウレタンを、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が１８．４％となるように、接圧を加えて選択的に除去したこと以外は同様にして、着色された立毛人工皮革を得た。その評価結果を表１に示す。 (Comparative example 3)
In Example 1, instead of the DMF solution (solid content 15%) of polycarbonate polyurethane with a 100% modulus of 4.5 MPa, carbon black was added and colored so that the content was 1.0% by mass. A DMF solution (solid content 15%) of polycarbonate polyurethane with a modulus of 4.5 MPa was used, and the area ratio of polycarbonate polyurethane present on the napped surface was 5%. Instead of selectively removing the polycarbonate polyurethane present in the entangled web by applying contact pressure, the polycarbonate polyurethane present in the entangled web was removed by contact pressure such that the area ratio of the polycarbonate polyurethane present on the napped surface was 18.4%. Colored napped artificial leather was obtained in the same manner, except that 20% of the product was added and selectively removed. The evaluation results are shown in Table 1.
（比較例４）
　実施例１において、海成分としてポリエチレンを使用する代わりにポリビニルアルコ－ルを使用したこと、トルエン中に浸漬し海成分であるポリエチレンを溶解除去した代わりに、熱水中に浸漬しポリエチレンを溶解除去したこと、１００％モジュラス４．５ＭＰａのポリカーボネート系ポリウレタンのＤＭＦ溶液（固形分１５％）に、立毛人工皮革中の高分子弾性体の含有量が１８質量％になるように、熱収縮処理された不織布を含浸させた代わりに、１００％モジュラス３．０ＭＰａの自己乳化型の非晶性ポリカーボネート系ポリウレタンエマルジョン溶液（固形分１５質量％）に、立毛人工皮革中の高分子弾性体の含有量が１０質量％になるように、熱収縮処理された絡合ウェブを含浸させたこと以外は同様にして、着色された立毛人工皮革を得た。その評価結果を表１に示す。 (Comparative example 4)
In Example 1, polyvinyl alcohol was used instead of polyethylene as the sea component, and instead of being immersed in toluene to dissolve and remove polyethylene as a sea component, it was immersed in hot water to dissolve and remove polyethylene. Then, a DMF solution (solid content 15%) of polycarbonate-based polyurethane with a 100% modulus of 4.5 MPa was heat-shrinked so that the content of the polymeric elastomer in the napped artificial leather was 18% by mass. Instead of impregnating the nonwoven fabric, a self-emulsifying amorphous polycarbonate-based polyurethane emulsion solution (solid content 15% by mass) with a 100% modulus of 3.0 MPa was impregnated with a polymer elastomer content of 10% in the napped artificial leather. Colored napped artificial leather was obtained in the same manner except that a heat-shrinkable entangled web was impregnated so as to achieve the same weight %. The evaluation results are shown in Table 1.
（比較例５）
　島成分としてポリエチレンテレフタレート（ＰＥＴ）、海成分としてポリエチレンを準備し、島数が１６島となるような溶融複合用口金を用い、海成分／島成分の質量比が３５／６５となるように圧力調整をして口金温度設定２８０℃、単孔吐出１．２ｇ／ｍｉｎで吐出させ、紡糸速度８２０ｍ／ｍｉｎで紡糸した後、延伸、捲縮処理を行い、繊度３．６ｄｔｅｘの短繊維である海島型複合繊維を得た。
　得られた海島型複合繊維をカードへ通過させ、短繊維のウェブを製造した。
　得られたウェブを複数枚枚積層し、積層ウェブを形成した。そして、積層ウェブに対して１バーブのニードル針を用いて２０５０本／ｃｍ２のパンチング密度でニードルパンチ処理を行うことにより、目付け６００ｇ／ｍ２の絡合ウェブを形成した。得られた絡合ウェブを９０℃の熱水で収縮処理を行い、乾燥後、熱プレスすることにより、目付８００ｇ／ｍ２の熱収縮処理された絡合ウェブを得た。
　続いて、高分子弾性体である１００％モジュラス４．５ＭＰａのポリカーボネート系ポリウレタンのＤＭＦ溶液（固形分１５質量％）に、立毛人工皮革中の高分子弾性体の含有量が４０質量％になるように、熱収縮処理された絡合ウェブを含浸させた。含浸させた後、その絡合ウェブ表面に存在するポリカーボネート系ポリウレタンを、立毛面に存在するポリカーボネート系ポリウレタンの面積比率が５％となるように、接圧を加えて選択的に除去した後、水：ＤＭＦが質量比で７０：３０のＤＭＦ水溶液に浸漬してポリカーボネート系ポリウレタンを凝固させ、絡合ウェブにポリカーボネート系ポリウレタン（ポリウレタン系樹脂）を付与した。
　次に、ポリウレタン系樹脂が付与された絡合ウェブを、ニップ処理をしつつ、８５℃のトルエン中に浸漬し、海成分であるポリエチレンを溶解除去した後、乾燥し、ポリエステルの極細繊維を含み、高分子弾性体としてポリウレタン系樹脂が付与された不織布を得た。得られた不織布の目付は６５４ｇ／ｍ２であった。
　得られた不織布を、人工皮革生機とするため厚み方向に半裁し、半裁面側を♯１８０、♯２４０のサンドペーパーでバフィング後、さらに、非半裁面を♯３２０、♯６００のサンドペーパーで研削の一方の面をバフィング処理することにより、立毛面を有する立毛人工皮革を得た。
　続いて、得られた立毛人工皮革を、分散染料を染料濃度６％ｏｗｆに調整し、サーキュラー染色機にて１３０℃高圧染色を行い、その後還元洗浄、酸化処理、水洗を行うことにより、着色された立毛人工皮革を得た。着色された立毛人工皮革の評価結果を表１に示す。 (Comparative example 5)
Prepare polyethylene terephthalate (PET) as the island component and polyethylene as the sea component, and use a melting composite nozzle so that the number of islands is 16, and pressurize so that the mass ratio of the sea component/island component is 35/65. After adjusting the nozzle temperature setting to 280°C and discharging at a single hole discharge rate of 1.2 g/min, and spinning at a spinning speed of 820 m/min, stretching and crimping are performed to obtain sea islands, which are short fibers with a fineness of 3.6 dtex. A composite fiber was obtained.
The obtained sea-island composite fibers were passed through a card to produce a short fiber web.
A plurality of sheets of the obtained web were laminated to form a laminated web. Then, the laminated web was subjected to needle punching using a 1-barb needle at a punching density of 2050 punches/cm 2 to form an entangled web with a basis weight of 600 g/m 2 . The resulting entangled web was subjected to shrinkage treatment with hot water at 90°C, dried, and then hot pressed to obtain a heat-shrinkable entangled web with a basis weight of 800 g/m 2 .
Next, a DMF solution (solid content 15% by mass) of a polycarbonate polyurethane having a 100% modulus of 4.5 MPa, which is a polymeric elastic material, was added so that the content of the polymeric elastic material in the napped artificial leather was 40% by mass. was impregnated with a heat-shrinked entangled web. After impregnation, the polycarbonate polyurethane present on the surface of the entangled web is selectively removed by applying contact pressure so that the area ratio of the polycarbonate polyurethane present on the napped surface is 5%, and then water is applied. :DMF was immersed in a DMF aqueous solution having a mass ratio of 70:30 to coagulate the polycarbonate-based polyurethane, thereby imparting polycarbonate-based polyurethane (polyurethane-based resin) to the entangled web.
Next, the entangled web to which the polyurethane resin has been applied is dipped in toluene at 85°C while being nipped to dissolve and remove the polyethylene, which is a sea component, and then dried. A nonwoven fabric to which a polyurethane resin was applied as a polymeric elastomer was obtained. The fabric weight of the obtained nonwoven fabric was 654 g/m 2 .
The obtained nonwoven fabric was cut in half in the thickness direction to make artificial leather raw material, and the half-cut side was buffed with #180 and #240 sandpaper, and then the non-half-cut side was ground with #320 and #600 sandpaper. A napped artificial leather having a napped surface was obtained by buffing one side of the material.
Next, the obtained raised artificial leather was colored by adjusting the disperse dye to a dye concentration of 6% owf, performing high-pressure dyeing at 130 ° C in a circular dyeing machine, and then performing reduction cleaning, oxidation treatment, and water washing. A raised artificial leather was obtained. Table 1 shows the evaluation results of the colored raised artificial leather.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　実施例１～６で得られた立毛人工皮革は、立毛面から高分子弾性体（ポリウレタン系樹脂）が全くあるいは極僅かしか視認されず、染色ムラが抑制され、発色性に優れるものであった。また、立毛が細かく分散した状態で均一な長さを有し、スムースな感触であった。 In the napped artificial leathers obtained in Examples 1 to 6, no or very little polymeric elastomer (polyurethane resin) was visible from the napped surface, uneven dyeing was suppressed, and color development was excellent. . In addition, the nape was finely dispersed, had a uniform length, and had a smooth feel.
　一方、比較例１で得られた立毛人工皮革は、高分子弾性体の含有量が１５～３５質量％の範囲にあり、立毛繊維長が２５０μｍ以下であるが、立毛面に存在する高分子弾性体の面積比率は１７％超であり、立毛面から高分子弾性体（ポリウレタン系樹脂）がムラ状に視認され、染色ムラが発生していた。 On the other hand, the napped artificial leather obtained in Comparative Example 1 has a polymer elastomer content in the range of 15 to 35% by mass and a napped fiber length of 250 μm or less; The area ratio of the body was more than 17%, and the polymeric elastic material (polyurethane resin) was visible unevenly from the raised surface, causing uneven dyeing.
　比較例２で得られた立毛人工皮革は、高分子弾性体の含有量が１５～３５質量％の範囲にあり、立毛面に存在する高分子弾性体の面積比率は１７％以下であるが、立毛繊維長が２５０μｍ超であり、立毛が粗くばらけて不均一な長さを有し、粗い感触でライティングのないものであった。 The napped artificial leather obtained in Comparative Example 2 has an elastic polymer content in the range of 15 to 35% by mass, and the area ratio of the elastic polymer present on the napped surface is 17% or less. The napped fiber length was more than 250 μm, and the napped fibers were coarsely scattered and had non-uniform lengths, giving a rough feel and no writing.
　比較例３で得られた立毛人工皮革は、高分子弾性体の含有量が１５～３５質量％の範囲にあり、立毛繊維長が２５０μｍ以下であるが、立毛面に存在する高分子弾性体の面積比率が１７％超である。高分子弾性体がカーボンブラックを含むため、染色ムラは多少抑制されているもの、視認できる程度に発生していた。 The napped artificial leather obtained in Comparative Example 3 has a polymer elastomer content in the range of 15 to 35% by mass, and a napped fiber length of 250 μm or less. The area ratio is over 17%. Since the polymeric elastomer contained carbon black, uneven dyeing was somewhat suppressed, but it still occurred to a visible degree.
　比較例４で得られた立毛人工皮革は、立毛面に存在する高分子弾性体の面積比が１７％以下であり、立毛繊維長が２５０μｍ以下であるが、不織布に付与された高分子弾性体が１５～３５質量％の範囲の下限以下を満たしておらず、この立毛人工皮革は、柔軟性及び弾力性が劣り、硬い風合いの立毛人工皮革であった。 In the napped artificial leather obtained in Comparative Example 4, the area ratio of the polymeric elastomer present on the napped surface is 17% or less, and the napped fiber length is 250 μm or less. did not satisfy the lower limit of the range of 15 to 35% by mass, and this napped artificial leather had poor flexibility and elasticity, and had a hard texture.
　比較例５で得られた立毛人工皮革は、短繊維を使用した厚み０．４ｍｍの立毛人工皮革であって、立毛繊維長が２５０μｍ以下であるが、不織布に付与された高分子弾性体の含有量が１５～３５質量％の範囲の上限を超え、また立毛面に存在する高分子弾性体の面積比率も１７％超であるため、立毛面から高分子弾性体（ポリウレタン系樹脂）がムラ状に視認され、染色ムラが発生しており、十分な機械的強度を有しないものであった。

  The napped artificial leather obtained in Comparative Example 5 is a napped artificial leather with a thickness of 0.4 mm using staple fibers, and the napped fiber length is 250 μm or less. Since the amount exceeds the upper limit of the range of 15 to 35% by mass, and the area ratio of the polymeric elastic material present on the napped surface is more than 17%, the polymeric elastic material (polyurethane resin) is uneven from the napped surface. It was visually recognized that uneven dyeing had occurred, and it did not have sufficient mechanical strength.

Claims (8)

  1. 　極細繊維と、高分子弾性体とを含有する不織布を含み、立毛面を有する立毛人工皮革であって、
    　前記高分子弾性体の含有量が１５～３５質量％であり、
    　前記立毛面に存在する前記高分子弾性体の面積比率が１７％以下であり、
    　立毛繊維長が２５０μｍ以下である、立毛人工皮革。     A napped artificial leather comprising a nonwoven fabric containing ultrafine fibers and a polymeric elastomer and having a napped surface,
    The content of the polymeric elastomer is 15 to 35% by mass,
    The area ratio of the polymer elastic body present on the nap surface is 17% or less,
    Napped artificial leather having a napped fiber length of 250 μm or less.
  2. 　前記極細繊維が、ポリエステル系繊維である、請求項１に記載の立毛人工皮革。 The napped artificial leather according to claim 1, wherein the ultrafine fiber is a polyester fiber.
  3. 　前記極細繊維の平均繊度が、０．０１～１．０ｄｔｅｘである、請求項１又は２に記載の立毛人工皮革。 The napped artificial leather according to claim 1 or 2, wherein the average fineness of the ultrafine fibers is 0.01 to 1.0 dtex.
  4. 　前記不織布が、スパンボンド不織布である、請求項１～３のいずれか１項に記載の立毛人工皮革。 The raised artificial leather according to any one of claims 1 to 3, wherein the nonwoven fabric is a spunbond nonwoven fabric.
  5. 　請求項１～４のいずれか１項に記載の立毛人工皮革の製造方法であって、
    　前記高分子弾性体を含有する絡合ウェブから、海成分を除去して、前記高分子弾性体を含有する不織布を得る工程を含む、立毛人工皮革の製造方法。     A method for producing napped artificial leather according to any one of claims 1 to 4, comprising:
    A method for producing napped artificial leather, the method comprising the step of removing a sea component from the entangled web containing the elastic polymer to obtain a nonwoven fabric containing the elastic polymer.
  6. 　海島型複合繊維を溶融紡糸してウェブを得る工程を含む、請求項５に記載の立毛人工皮革の製造方法。 The method for producing napped artificial leather according to claim 5, comprising the step of melt-spinning sea-island composite fibers to obtain a web.
  7. 　前記高分子弾性体を含有する不織布を得る工程において、有機溶剤を用いて前記海成分を溶解除去する、請求項６に記載の立毛人工皮革の製造方法。 The method for producing napped artificial leather according to claim 6, wherein in the step of obtaining the nonwoven fabric containing the polymeric elastomer, the sea component is dissolved and removed using an organic solvent.
  8. 　溶剤系ポリウレタンを用いて前記高分子弾性体を含有する絡合ウェブを得る工程を有する、請求項５～７のいずれか１項に記載の立毛人工皮革の製造方法。 The method for producing napped artificial leather according to any one of claims 5 to 7, comprising the step of obtaining an entangled web containing the polymeric elastomer using a solvent-based polyurethane.
PCT/JP2023/024418 2022-07-05 2023-06-30 Napped artificial leather and manufacturing method therefor WO2024009907A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004143654A (en) * 2002-09-30 2004-05-20 Kuraray Co Ltd Sueded artificial leather and method for producing the same
JP2008280643A (en) * 2007-05-11 2008-11-20 Kuraray Co Ltd Suede-like artificial leather and method for producing the same
JP2015509149A (en) * 2012-01-17 2015-03-26 アルカンターラ エス．ピー．エー．Ａｌｃａｎｔａｒａ Ｓ．Ｐ．Ａ． Microfiber products and their use for the production of covers and containers
WO2020003866A1 (en) * 2018-06-29 2020-01-02 東レ株式会社 Sheet-shaped item and manufacturing method therefor
WO2020189592A1 (en) * 2019-03-20 2020-09-24 東レ株式会社 Sheet-like material
WO2021049413A1 (en) * 2019-09-10 2021-03-18 株式会社クラレ Napped artificial leather

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004143654A (en) * 2002-09-30 2004-05-20 Kuraray Co Ltd Sueded artificial leather and method for producing the same
JP2008280643A (en) * 2007-05-11 2008-11-20 Kuraray Co Ltd Suede-like artificial leather and method for producing the same
JP2015509149A (en) * 2012-01-17 2015-03-26 アルカンターラ エス．ピー．エー．Ａｌｃａｎｔａｒａ Ｓ．Ｐ．Ａ． Microfiber products and their use for the production of covers and containers
WO2020003866A1 (en) * 2018-06-29 2020-01-02 東レ株式会社 Sheet-shaped item and manufacturing method therefor
WO2020189592A1 (en) * 2019-03-20 2020-09-24 東レ株式会社 Sheet-like material
WO2021049413A1 (en) * 2019-09-10 2021-03-18 株式会社クラレ Napped artificial leather

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