Abstract: Protein fibers for artificial hair include a polycation, wherein the protein fibers for artificial hair are crosslinked with an organic compound and/or a metal salt, and the protein fibers for artificial hair have curls. A method for producing the protein fibers for artificial hair includes treating artificial protein fibers that are crosslinked with an organic compound and/or a metal salt with a treatment solution containing a polycation, and curling the artificial protein fibers, or curling artificial protein fibers that are crosslinked with an organic compound and/or a metal salt, and treating the curled artificial protein fibers with a treatment solution containing a polycation.

Abstract: Protein fibers for artificial hair include a polycation, wherein the protein fibers for artificial hair are crosslinked with an organic compound and/or a metal salt, and the protein fibers for artificial hair have curls. A method for producing the protein fibers for artificial hair includes treating artificial protein fibers that are crosslinked with an organic compound and/or a metal salt with a treatment solution containing a polycation, and curling the artificial protein fibers, or curling artificial protein fibers that are crosslinked with an organic compound and/or a metal salt, and treating the curled artificial protein fibers with a treatment solution containing a polycation.

Abstract: The present invention relates to a pile fabric including an acrylic synthetic fiber at a napped portion, the acrylic synthetic fiber is obtained by spinning a spinning solution including 90 to 99 parts by weight of a polymer A and 1 to 10 parts by weight of a polymer B. The polymer A is a polymer obtained by polymerizing a composition A including 40 to 97 wt % of acrylonitrile, 0 to 5 wt % of a sulfonic acid-containing monomer and 3 to 60 wt % of another copolymerizable monomer. The polymer B is obtained by polymerizing a composition B including 0 to 70 wt % of acrylonitrile, 20 to 90 wt % of acrylic ester and 10 to 40 wt % of a sulfonic acid-containing monomer, and the polymer B is a polymer to be dissolved in a mixed solvent composed of water and at least one organic solvent selected from the group consisting of N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide and acetone.

Abstract: The present invention relates to a pile fabric including an acrylic synthetic fiber at a napped portion, the acrylic synthetic fiber is obtained by spinning a spinning solution including 90 to 99 parts by weight of a polymer A and 1 to 10 parts by weight of a polymer B. The polymer A is a polymer obtained by polymerizing a composition A including 40 to 97 wt % of acrylonitrile, 0 to 5 wt % of a sulfonic acid-containing monomer and 3 to 60 wt % of another copolymerizable monomer. The polymer B is obtained by polymerizing a composition B including 0 to 70 wt % of acrylonitrile, 20 to 90 wt % of acrylic ester and 10 to 40 wt % of a sulfonic acid-containing monomer, and the polymer B is a polymer to be dissolved in a mixed solvent composed of water and at least one organic solvent selected from the group consisting of N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide and acetone.

Abstract: A pile fabric whose pile fibers are prevented from falling off without impairing the texture by fusing only a specific area of the pile fabric. The pile fabric has a ground structure and pile fibers that are intertwined with ground yarns and napped on a front surface of the ground structure. The pile fibers including acrylic fibers and/or acrylic-based fibers and have a softening point lower than a softening point of the ground structure fibers, and are intertwined with the ground yarns. At least part of the pile fibers located outside of the ground yarns are fused but the pile fibers napped on the front surface of the ground structure are not fused. A method of producing a pile fabric includes a contact heating/pressurization step at a temperature equal to or higher than the softening point of the pile fibers and lower than the softening point of the ground structure fibers.

Abstract: A modacrylic shrinkable fiber according to the present invention is containing a polymer composition obtained by mixing 50 to 99 parts by weight of a polymer (A) containing 40 wt % to 80 wt % of acrylonitrile, 20 wt % to 60 wt % of a halogen-ontaining monomer and 0 wt % to 5 wt % of a sulfonic-acid-containing monomer, and 1 to 50 parts by weight of a polymer (B) containing 5 wt % to 70 wt % of acrylonitrile, 20 wt % to 94 wt % of an acrylic ester and 1 wt % to 40 wt % of a sulfonic-acid-containing monomer containing a methallylsulfonic acid or metal salts thereof or amine salts thereof, in which a total amount of the polymer (A) and the polymer (B) is 100 parts by weight. In this way, a modacrylic shrinkable fiber that has a favorable color development property after dyeing and a high shrinkage ratio even after dyeing is obtained.

Abstract: A step pile fabric according to the present invention contains a non-shrinkable fiber, and a shrinkable fiber containing a modacrylic copolymer. A composition of the shrinkable fiber containing the modacrylic copolymer contains a polymer composition obtained by mixing i) 60 to 99 parts by weight of a copolymer (A) containing 35 wt % to 98 wt % of acrylonitrile, and 2 wt % to 65 wt % of a total amount of 0.5 wt % to 5.0 wt % of a sulfonic-group-containing monomer and other vinyl monomer, and ii) 1 to 40 parts by weight of a copolymer (B) containing 0 wt % to 90 wt % of acrylonitrile, 2 wt % to 40 wt % of a sulfonic-group-containing monomer, and 0 wt % to 80 wt % of other vinyl monomer containing no halogen. A dry heat shrinkage S of the shrinkable fiber at 130° C. for 5 minutes after dyeing is 15% to 40%.

Abstract: A modacrylic shrinkable fiber according to the present invention is containing a polymer composition obtained by mixing 50 to 99 parts by weight of a polymer (A) containing 40 wt % to 80 wt % of acrylonitrile, 20 wt % to 60 wt % of a halogen-ontaining monomer and 0 wt % to 5 wt % of a sulfonic-acid-containing monomer, and 1 to 50 parts by weight of a polymer (B) containing 5 wt % to 70 wt % of acrylonitrile, 20 wt % to 94 wt % of an acrylic ester and 1 wt % to 40 wt % of a sulfonic-acid-containing monomer containing a methallylsulfonic acid or metal salts thereof or amine salts thereof, in which a total amount of the polymer (A) and the polymer (B) is 100 parts by weight. In this way, a modacrylic shrinkable fiber that has a favorable color development property after dyeing and a high shrinkage ratio even after dyeing is obtained.

Abstract: An acrylic shrinkable fiber that can be dyed at a low temperature, and has a high shrinkage percentage even after drying is provided. A dyeable acrylic shrinkable fiber comprising 50 to 99 parts by weight of a polymer (A) comprising 80 to 97 wt % of acrylonitrile, 0 to 2 wt % of a sulfonic acid group-containing monomer and 3 to 20 wt % of a monomer copolymerizable with the monomers; and 1 to 50 parts by weight of a polymer (B) comprising 0 to 89 wt % of acrylonitrile, 1 to 40 wt % of a sulfonic acid group-containing monomer and 10 to 99 wt % of a monomer copolymerizable with the monomers, wherein the polymers (A) and (B) are 100 parts by weight in total is provided.

Abstract: An object of the present invention is to provide a dyeable acrylic shrinkable fiber that only slightly shrinks when dyed and has a high shrinkage percentage even after dyeing. By spinning an incompatible spinning solution, the above object can be achieved, and a dyeable acrylic shrinkable fiber that only slightly shrinks when dyed and has a high shrinkage percentage even after dyeing can be provided.

Abstract: An increased number of colors can be assorted in the down hair part of a step pile fabric more easily than before by carrying out dry heat treatment of a pile fabric comprising an acrylic shrinkable fiber that can be dyed in a specific low-temperature region. There is provided a step pile fabric obtained by treating a pile fabric comprising an acrylic shrinkable fiber, which comprises comprising an acrylic copolymer comprising 0.5 to 10 wt % of a sulfonic acid group-containing monomer, dyed at 55 to 85° C., with dry heat at 110 to 150° C. for 20 minutes or less, the acrylic shrinkable fiber having a shrinkage percentage of 18% or more calculated by the following formula (1): Shrinkage percentage (%)=100×(1?Sa/Sb)??(1) wherein Sb represents a pile length of the down hair component before the dry heat treatment, and Sa represents a pile length of the down hair part (component) after the dry heat treatment.