Dyeing agent composition for regenerated collagen fibers

Abstract

A dyeing agent composition for regenerated collagen fibers, which is used by mixing at least a first agent and a second agent at the time of use, wherein the first agent contains a specific oxidation dye intermediate (A), an alkali agent, and water, the second agent contains hydrogen peroxide and water, and the regenerated collagen fibers contain modified regenerated collagen fibers containing a specific compound (B).

Description

Dyeing composition for regenerated collagen fibers

[0001] The present invention relates to a dye composition for use on regenerated collagen fibers.

[0002] Regenerated collagen fiber, a protein fiber, is suitable for use as a raw material for artificial hair because its properties are similar to those of human hair. Fibers used as raw materials for artificial hair are required to have high aesthetic qualities, such as color development and texture.

[0003] Protein fibers are generally colored by dyeing. A dyeing method in which protein fibers are immersed in an aqueous dye solution maintained at 70 to 100°C is used as the dyeing method. For example, Patent Document 1 describes a dyeing method in which wool is immersed in an aqueous dye solution containing an enzyme or the like to improve dye leveling, and then boiled at 100°C for 60 minutes. Patent Document 2 describes a method for dyeing protein fibers such as wool, cashmere, and silk thread at a temperature range of 70 to 90°C, which is lower than conventional dyeing temperatures, by using a specific treating agent. Furthermore, the example discloses an example in which wool is treated with a specific treating agent and then dyed at a dyeing temperature of 85°C.

[0004] (Patent Document 1) JP-A-2-216282 (Patent Document 2) JP-A-7-126988

[0005] The present invention relates to the following: [1] A dye composition for regenerated collagen fibers, which uses a mixture of at least a first agent and a second agent, wherein the first agent contains an oxidation dye intermediate (A) containing one or more compounds selected from the group consisting of the following components (A1) and (A2), an alkaline agent, and water, the second agent contains hydrogen peroxide and water, and the regenerated collagen fibers comprise modified regenerated collagen fibers containing one or more compounds (B) selected from the group consisting of the following components (B1) and (B2).

[0006] (A1) One or more couplers selected from the group consisting of couplers (A1-1) having a benzene ring, electron-donating groups at the 1st and 3rd positions on the benzene ring, and hydrogen atoms at the 4th and 6th positions; couplers (A1-2) having a pyridine ring, electron-donating groups at the 2nd and 6th positions on the pyridine ring, and hydrogen atoms at the 3rd and 5th positions; and couplers (A1-3) represented by the following general formula (A13):

[0007]

[0008] (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group, or an electron-donating group.

[0009] (A2) One or more couplers other than the component (A1), selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions.

[0010] (B1) Benzoic acid or a salt thereof. (B2) A copolymer containing a structural unit derived from an unsaturated monomer having a carboxy group and a structural unit derived from an aromatic vinyl compound, the copolymer having an acid value of 100 mgKOH / g or more and a weight average molecular weight of 1,500 or more and 15,000 or less, or a salt thereof.

[0011] [2] A method for dyeing regenerated collagen fibers, the method comprising the following steps (I) and (II) in this order, wherein the regenerated collagen fibers comprise modified regenerated collagen fibers containing one or more compounds (B) selected from the group consisting of component (B1) and component (B2):

[0012] Step (I): A step of preparing a dye composition for regenerated collagen fibers by mixing at least a first agent and a second agent, wherein the first agent contains the oxidative dye intermediate (A) containing one or more selected from the group consisting of the component (A1) and the component (A2), an alkaline agent, and water, and the second agent contains hydrogen peroxide and water. Step (II): A step of applying the dye composition for regenerated collagen fibers to the regenerated collagen fibers.

[0013] [3] A colored modified regenerated collagen fiber containing the following components (A0) and (B): (A0) a reaction product of the oxidation dye intermediate (A) containing at least one selected from the group consisting of the components (A1) and (A2), (B) at least one compound selected from the group consisting of the following components (B1) and (B2): (B1) benzoic acid or a salt thereof, (B2) a copolymer containing a structural unit derived from an unsaturated monomer having a carboxy group and a structural unit derived from an aromatic vinyl compound, the copolymer having an acid value of 100 mg KOH / g or more and a weight average molecular weight of 1,500 to 15,000, or a salt thereof. [4] A head ornament product containing the colored modified regenerated collagen fiber according to [3]. Detailed Description of the Invention

[0014] In conventional general dyeing methods for protein fibers, such as those disclosed in Patent Documents 1 and 2, even when special treatment agents are used, the dye cannot be sufficiently absorbed unless treatment is performed at a high temperature exceeding 70° C. Furthermore, when regenerated collagen fibers are dyed using a dyeing method that requires high-temperature conditions exceeding 70° C., there is a problem in that the regenerated collagen fibers shrink.

[0015] In order to solve the above problems, the present inventors attempted to dye regenerated collagen fibers at temperatures below 70°C. However, when the dyeing temperature was low, the chemical reaction between the regenerated collagen fibers and the dye became insufficient, resulting in a problem of reduced dye fastness.

[0016] Therefore, the only practical method for coloring regenerated collagen fibers is to disperse a pigment such as carbon black in the solution spinning process of the regenerated collagen fibers. However, with coloring methods using pigments, the range of colors that can be colored is limited to achromatic colors such as black and gray, as well as chromatic colors such as red, yellow, blue, and purple, but it is difficult to produce vivid colors such as deep black.

[0017] Therefore, the present invention relates to a dye composition for regenerated collagen fibers that uses a dye and provides excellent fastness to the regenerated collagen fibers.

[0018] The present inventors have found that a dye composition for regenerated collagen fibers, including specific modified regenerated collagen fibers, which uses a specific oxidative dye intermediate, can solve the above-mentioned problems. According to the present invention, a dye composition for regenerated collagen fibers, which uses a dye, and which has excellent fastness for the specific modified regenerated collagen fibers, can be provided.

[0019] [Definitions] In this specification, "excellent dyeability of regenerated collagen fibers" means that there is a large change in color of regenerated collagen fibers before and after dyeing with a dye composition for regenerated collagen fibers. Furthermore, "fastness" means that there is little change in color after the dyed regenerated collagen fibers are washed with water, a detergent, etc. The dyeability and fastness can be specifically evaluated by the methods described in the examples.

[0020] [Dye composition for regenerated collagen fibers] The dye composition for regenerated collagen fibers of the present invention is a dye composition for regenerated collagen fibers that uses a mixture of at least a first agent and a second agent, wherein the first agent contains an oxidation dye intermediate (A) containing one or more compounds selected from the group consisting of the following components (A1) and (A2), an alkaline agent, and water; the second agent contains hydrogen peroxide and water; and the regenerated collagen fibers comprise modified regenerated collagen fibers that contain one or more compounds (B) selected from the group consisting of the following components (B1) and (B2).

[0021] (A1) One or more couplers selected from the group consisting of couplers (A1-1) having a benzene ring, electron-donating groups at the 1st and 3rd positions on the benzene ring, and hydrogen atoms at the 4th and 6th positions; couplers (A1-2) having a pyridine ring, electron-donating groups at the 2nd and 6th positions on the pyridine ring, and hydrogen atoms at the 3rd and 5th positions; and couplers (A1-3) represented by the following general formula (A13):

[0022]

[0023] (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group, or an electron-donating group.

[0024] (A2) One or more couplers other than the component (A1), selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions.

[0025] (B1) Benzoic acid or a salt thereof. (B2) A copolymer containing a structural unit derived from an unsaturated monomer having a carboxy group and a structural unit derived from an aromatic vinyl compound, the copolymer having an acid value of 100 mgKOH / g or more and a weight average molecular weight of 1,500 or more and 15,000 or less, or a salt thereof.

[0026] In the following description, the dye composition for regenerated collagen fibers may be simply referred to as the "composition (of the present invention)." Because the composition of the present invention has the above-described configuration, even though it is a dye-based dye composition, it exhibits excellent fastness to specific modified regenerated collagen fibers.

[0027] The reason why the composition of the present invention exhibits the above-mentioned effects is unclear, but is presumed to be as follows. The composition of the present invention is a dye composition prepared by mixing a first agent containing an alkaline agent with a second agent containing hydrogen peroxide. The first agent contains one or more specific oxidative dye intermediates selected from the group consisting of the aforementioned components (A1) and (A2) as dye precursors. The oxidative dye intermediates are low-molecular-weight compounds, and when a dye composition containing the oxidative dye intermediates is applied to regenerated collagen fibers, it easily penetrates into the fibers. The penetration of the oxidative dye intermediates into the fibers is promoted by the alkaline agent contained in the first agent. After penetration into the fibers, the oxidative dye intermediates react with each other or with the precursor due to the action of hydrogen peroxide contained in the second agent to form a reaction product, which develops color and exhibits dyeability. Here, the oxidative dye intermediate (A1) used in the present invention is a coupler having a specific structure, and this structure makes component (A1) more likely to form a reaction product of trimers or higher. Similarly, the coupler of component (A2) also has a specific structure, which makes it easy to form reaction products of dimers or higher. Therefore, it is thought that the use of one or more oxidation dye intermediates selected from the group consisting of components (A1) and (A2) makes it easy to generate reaction products with high molecular weights inside the fiber, thereby improving fastness.

[0028] Furthermore, the regenerated collagen fibers to be dyed with the composition of the present invention include modified regenerated collagen fibers (hereinafter simply referred to as "modified regenerated collagen fibers") containing one or more compounds (B) selected from the group consisting of the aforementioned components (B1) and (B2). Compound (B) acts as a modifier for the regenerated collagen fibers. Furthermore, within the modified regenerated collagen fibers, the structural moiety derived from compound (B) interacts with the specific oxidative dye intermediate and its reaction product, which is thought to facilitate retention of the oxidative dye intermediate and its reaction product within the fibers without heat treatment, thereby further improving fastness. The mechanism of action of the present invention is not limited to the above.

[0029] <First Agent> The first agent contains an oxidation dye intermediate (A) containing one or more selected from the group consisting of the following components (A1) and (A2), an alkali agent, and water: (A1) One or more selected from the group consisting of a coupler (A1-1) having a benzene ring, electron-donating groups at the 1st and 3rd positions on the benzene ring, and hydrogen atoms at the 4th and 6th positions, a coupler (A1-2) having a pyridine ring, electron-donating groups at the 2nd and 6th positions on the pyridine ring, and hydrogen atoms at the 3rd and 5th positions, and a coupler (A1-3) represented by the following general formula (A13):

[0030]

[0031] (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group, or an electron-donating group.

[0032] (A2) One or more couplers other than the component (A1), selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions.

[0033] (Oxidation dye intermediate (A)) The oxidation dye intermediate (A) contains one or more selected from the group consisting of the following components (A1) and (A2): (A1) one or more selected from the group consisting of couplers (A1-1) having a benzene ring, having electron-donating groups at the 1- and 3-positions on the benzene ring, and hydrogen atoms at the 4- and 6-positions, couplers (A1-2) having a pyridine ring, having electron-donating groups at the 2- and 6-positions on the pyridine ring, and hydrogen atoms at the 3- and 5-positions, and couplers (A1-3) represented by the following general formula (A13):

[0034]

[0035] (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group, or an electron-donating group.

[0036] (A2) One or more couplers other than the component (A1), selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions.

[0037] In this specification, the term "coupler" does not include compounds having a catechin structure. The term "catechin structure" as used herein specifically refers to a structure represented by the following general formula (I):

[0038]

[0039] (In the formula, R A and R B are each independently a hydrogen atom or a hydroxy group. C is a hydrogen atom or an acyl group, and R D is a hydrogen atom or a ring structure-containing group. C The acyl group in R is preferably a group represented by the following general formula (II): D The ring structure-containing group in the formula (III) is preferably a group represented by the following formula (III).

[0040]

[0041]

[0042] (In the above formula, * indicates a bond. R A ~R C is the same as above.)

[0043] [Component (A1)] Component (A1) is one or more selected from the group consisting of couplers (A1-1) having a benzene ring, electron-donating groups at the 1- and 3-positions on the benzene ring, and hydrogen atoms at the 4- and 6-positions, couplers (A1-2) having a pyridine ring, electron-donating groups at the 2- and 6-positions on the pyridine ring, and hydrogen atoms at the 3- and 5-positions, and couplers (A1-3) represented by the following general formula (A13): Couplers (A1-1) to (A1-3) may be in the form of a salt, and the type of salt is not particularly limited.

[0044]

[0045] (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group, or an electron-donating group.

[0046] Examples of the electron-donating group in component (A1) include a hydroxy group, a hydroxyalkyl group, an alkoxy group, a hydroxyalkoxy group, a primary to tertiary amino group, an alkylamino group, and a hydrocarbon ring structure having aromaticity.

[0047] <Coupler (A1-1)> The coupler (A1-1) preferably includes a compound represented by the following general formula (A11) or a salt thereof.

[0048] (In formula (A11), R 1 is an electron donating group attached to the carbon atom at the 1st position, R 2 represents a hydrogen atom, an alkyl group or an electron-donating group bonded to the carbon atom at the 2-position, R 3 is an electron donating group attached to the 3-position carbon, R 4 is a hydrogen atom, an alkyl group, or an electron-donating group bonded to the carbon atom at the 5-position. 2 and R 3 may be bonded to each other to form a hydrocarbon ring structure having aromaticity.

[0049] The electron-donating group in general formula (A11) preferably comprises one or more selected from the group consisting of a hydroxy group, a hydroxyalkyl group, an alkoxy group, a hydroxyalkoxy group, a primary to tertiary amino group, an alkylamino group, and a hydrocarbon ring structure having aromaticity, more preferably comprises one or more selected from the group consisting of a hydroxy group, a hydroxyalkyl group having from 2 to 8 carbon atoms, an alkoxy group having from 1 to 8 carbon atoms, a hydroxyalkoxy group having from 2 to 8 carbon atoms, a primary amino group (-NH), and an alkylamino group having from 1 to 8 carbon atoms, and even more preferably comprises one or more selected from the group consisting of a hydroxy group and a primary amino group (-NH). The alkyl group preferably comprises an alkyl group having from 1 to 8 carbon atoms, more preferably an alkyl group having from 1 to 3 carbon atoms, and even more preferably a methyl group. The hydrocarbon ring structure having aromaticity is represented by R in general formula (A11). 2 and R 3 are bonded to each other to form an aromatic hydrocarbon ring structure, the ring structure includes an aromatic hydrocarbon ring structure having from 5 to 8 ring carbon atoms, more preferably an aromatic hydrocarbon ring structure having from 5 to 6 ring carbon atoms, and even more preferably an aromatic hydrocarbon ring structure having 6 ring carbon atoms.

[0050] In the general formula (A11), R 1 is preferably a hydroxy group or a primary amino group (—NH2). 2 is preferably a hydrogen atom or a methyl group, R 3 is preferably a hydroxy group or a primary amino group (—NH2). 2 and R 3 are bonded to each other to form an aromatic hydrocarbon ring structure having 6 ring carbon atoms. 4 is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom.

[0051] Specific examples of the compound represented by general formula (A11) include one or more compounds selected from the group consisting of meta-aminophenol, resorcinol, meta-phenylenediamine, 2-methylresorcinol, 1-naphthol, and salts thereof, and preferably include one or more compounds selected from the group consisting of meta-aminophenol, resorcinol, 2-methylresorcinol, 1-naphthol, and salts thereof.

[0052] <Coupler (A1-2)> The coupler (A1-2) preferably includes a compound represented by the following general formula (A12) or a salt thereof.

[0053]

[0054] (In formula (A12), R 5 is an electron donating group attached to the 2-position carbon, R 6 represents a hydrogen atom, an alkyl group or an electron-donating group bonded to the carbon atom at the 4-position, R 7 is an electron donating group attached to the 6-carbon atom.)

[0055] The electron-donating group in general formula (A12) preferably includes at least one selected from the group consisting of a hydroxy group, a hydroxyalkyl group, an alkoxy group, a hydroxyalkoxy group, a primary to tertiary amino group, and an alkylamino group, more preferably includes at least one selected from the group consisting of a hydroxy group, a hydroxyalkyl group having from 2 to 8 carbon atoms, an alkoxy group having from 1 to 8 carbon atoms, a hydroxyalkoxy group having from 2 to 8 carbon atoms, a primary amino group (-NH), and an alkylamino group having from 1 to 8 carbon atoms, even more preferably includes at least one selected from the group consisting of a hydroxy group and a primary amino group (-NH). The alkyl group preferably includes an alkyl group having from 1 to 8 carbon atoms, more preferably an alkyl group having from 1 to 3 carbon atoms, and even more preferably a methyl group.

[0056] In the general formula (A12), R 5 is preferably a hydroxy group or a primary amino group (—NH), and R 6 is preferably a hydrogen atom or a methyl group. 7is preferably a primary amino group (—NH2). Specific examples of the compound represented by general formula (A12) include 2,6-diaminopyridine and salts thereof.

[0057] <Coupler (A1-3)> The coupler (A1-3) preferably includes a compound represented by the following general formula (A13) or a salt thereof.

[0058]

[0059] (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group or an electron-donating group. The electron-donating group, the alkyl group and preferred embodiments thereof in general formula (A13) are the same as those in general formula (A12).

[0060] In general formula (A13), R 11 In the formula, n is preferably 2 or more and 8 or less, more preferably 2 or more and 4 or less. 12 , R 14 , R 22 and R 24 The electron donating group in R preferably comprises a hydroxy group or a primary amino group (—NH), and more preferably is a primary amino group (—NH). 13 , R 16 , R 23 and R 26 preferably contains a hydrogen atom or a methyl group, and more preferably is a hydrogen atom. Specific examples of the coupler represented by general formula (A13) include 1,3-bis(2,4-diaminophenoxy)propane and salts thereof.

[0061] As component (A1), one or more types selected from the group consisting of the couplers (A1-1), (A1-2), and (A1-3) can be used. Among the above, component (A1) preferably includes one or more types selected from the group consisting of the compounds represented by general formula (A11), the compounds represented by general formula (A12), the compounds represented by general formula (A13), and salts thereof, more preferably includes one or more types selected from the group consisting of meta-aminophenol, resorcinol, meta-phenylenediamine, 2-methylresorcinol, 1-naphthol, 2,6-diaminopyridine, 1,3-bis(2,4-diaminophenoxy)propane, and salts thereof, and even more preferably includes one or more types selected from the group consisting of meta-aminophenol, resorcinol, 2-methylresorcinol, 1-naphthol, and salts thereof.

[0062] [Component (A2)] Component (A2) is at least one coupler other than the component (A1) selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions.

[0063] <Coupler (A2-1)> The coupler (A2-1) preferably contains a compound represented by the following general formula (A21) or a salt thereof, excluding couplers corresponding to the above-mentioned component (A1).

[0064]

[0065] (In formula (A21), R 31 is an electron donating group attached to the carbon atom at the 1st position, R 32 is an electron donating group attached to the 2-position carbon, R 33 ~R 36 are hydrogen atoms, alkyl groups, or electron-donating groups bonded to the 3-, 4-, 5-, and 6-position carbons, respectively. 33 ~R 36 At least two of these are hydrogen atoms.)

[0066] The electron-donating group in general formula (A21) preferably includes at least one selected from the group consisting of a hydroxy group, a hydroxyalkyl group, an alkoxy group, a hydroxyalkoxy group, a primary to tertiary amino group, and an alkylamino group, more preferably includes at least one selected from the group consisting of a hydroxy group, a hydroxyalkyl group having from 2 to 8 carbon atoms, an alkoxy group having from 1 to 8 carbon atoms, a hydroxyalkoxy group having from 2 to 8 carbon atoms, a primary amino group (-NH), and an alkylamino group having from 1 to 8 carbon atoms, even more preferably includes at least one selected from the group consisting of a hydroxy group, a hydroxyalkoxy group having from 2 to 8 carbon atoms, and a primary amino group (-NH). The alkyl group preferably includes an alkyl group having from 1 to 8 carbon atoms, more preferably an alkyl group having from 1 to 3 carbon atoms, and even more preferably a methyl group.

[0067] In general formula (A21), R 31 is preferably a hydroxy group, a hydroxyalkoxy group having from 2 to 8 carbon atoms, or a primary amino group (—NH), and more preferably a hydroxy group, a hydroxyethoxy group, or a primary amino group (—NH). 32 is preferably a hydroxy group or a primary amino group (-NH2), more preferably a primary amino group (-NH2).

[0068] Specific examples of the compound represented by general formula (A21) include ortho-aminophenol, 2,4-diaminophenoxyethanol, and salts thereof.

[0069] <Coupler (A2-2)> The coupler (A2-2) preferably includes a compound represented by the following general formula (A22) or a salt thereof.

[0070]

[0071] (In formula (A22), R 37 is an electron donating group attached to the 2-position carbon, R 38 is an electron donating group attached to the 3-carbon atom. 39 ~R 41 are hydrogen atoms, alkyl groups, or electron-donating groups bonded to the 4-, 5-, and 6-position carbons, respectively.39 ~R 41 At least two of these are hydrogen atoms.)

[0072] The electron-donating group, the alkyl group, and preferred embodiments thereof in formula (A22) are the same as those in formula (A21).

[0073] In the general formula (A22), R 37 is preferably a hydroxy group or a primary amino group (—NH), and R 38 is preferably a hydroxy group or a primary amino group (—NH), more preferably a primary amino group (—NH). 39 ~R 41 are each independently preferably a hydrogen atom or a methyl group, more preferably R 39 ~R 41 are all hydrogen atoms. Specific examples of the compound represented by general formula (A22) include 2,3-diaminopyridine, 2-amino-3-hydroxypyridine, and salts thereof.

[0074] Component (A2) can be one or more selected from the group consisting of the couplers (A2-1) and (A2-2). Of the above, component (A2) preferably contains coupler (A2-1), and more preferably contains one or more selected from the group consisting of ortho-aminophenol, 2,4-diaminophenoxyethanol, and salts thereof.

[0075] Among the above, from the viewpoint of compatibility, the oxidation dye intermediate (A) preferably contains component (A1), more preferably contains one or more selected from the group consisting of meta-aminophenol, resorcinol, meta-phenylenediamine, 2-methylresorcinol, 1-naphthol, 2,6-diaminopyridine, 1,3-bis(2,4-diaminophenoxy)propane, and salts thereof. Also, the oxidation dye intermediate (A) preferably contains coupler (A1-1), more preferably contains one or more selected from the group consisting of meta-aminophenol, resorcinol, 2-methylresorcinol, and 1-naphthol.

[0076] From the viewpoint of improving dyeability and fastness, the total content of component (A1) and component (A2) in the oxidation dye intermediate (A) is preferably 30% by mass or more, more preferably 40% by mass or more, and 100% by mass or less. Furthermore, when the oxidation dye intermediate (A) contains another oxidation dye intermediate (for example, a precursor of component (A3) described below), the total content of component (A1) and component (A2) in the oxidation dye intermediate (A) may be, for example, 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less.

[0077] From the viewpoint of improving dyeability and fastness, the content of component (A1) in the oxidation dye intermediate (A) is preferably 30% by mass or more, more preferably 40% by mass or more, and 100% by mass or less. The content of component (A1) in the oxidation dye intermediate (A) may be, for example, 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less.

[0078] (Component (A3): Precursor) From the viewpoint of further improving dyeability and fastness, the oxidation dye intermediate (A) preferably further contains component (A3): precursor as an oxidation dye intermediate other than the components (A1) and (A2). The precursor can be any compound known as a precursor of an oxidation dye intermediate, and examples thereof include paraphenylenediamine, toluene-2,5-diamine, orthochloroparaphenylenediamine, N-phenylparaphenylenediamine, N,N-bis(hydroxyethyl)paraphenylenediamine, 3-methyl-4-aminophenol, 2-hydroxyethylparaphenylenediamine, paraaminophenol, paramethylaminophenol, 4-amino-metacresol, and salts thereof.

[0079] Among the above, from the viewpoint of further improving fastness when used in combination with the couplers of components (A1) and (A2), component (A3) preferably includes one or more members selected from the group consisting of toluene-2,5-diamine, para-aminophenol, 4-amino-metacresol, 1-hydroxyethyl-4,5-diaminopyrazole, and salts thereof.

[0080] When the oxidation dye intermediate (A) contains component (A3), the content of component (A3) in the oxidation dye intermediate (A) is, from the viewpoint of further improving dyeability and fastness, preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less. When the oxidation dye intermediate (A) contains component (A3), the content of component (A3) in the oxidation dye intermediate (A) is preferably 20% by mass or more and 70% by mass or less, more preferably 30% by mass or more and 65% by mass or less, and even more preferably 40% by mass or more and 60% by mass or less.

[0081] The oxidation dye intermediate (A) may further contain a coupler other than the components (A1) and (A2). However, from the viewpoint of further improving dyeability and fastness, the total content of the components (A1) to (A3) in the oxidation dye intermediate (A) is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and even more preferably 98% by mass or more, but not more than 100% by mass. That is, the content of couplers other than the components (A1) and (A2) in the oxidation dye intermediate (A) is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, still more preferably 5% by mass or less, and even more preferably 2% by mass or less, and may even be 0% by mass.

[0082] From the viewpoint of further improving dyeability and fastness, the molecular weight of the oxidation dye intermediate (A) is preferably 95 or more, more preferably 100 or more, and even more preferably 105 or more, as a non-dissociated type, from the viewpoint of efficiently penetrating into the interior of the fiber and further improving dyeability, and from the viewpoint of efficiently penetrating into the interior of the fiber, the molecular weight of the oxidation dye intermediate (A) is preferably 500 or less, more preferably 300 or less, and even more preferably 200 or less, as a non-dissociated type. The molecular weight of the oxidation dye intermediate (A) is preferably 95 or more and 500 or less, more preferably 100 or more and 300 or less, and even more preferably 105 or more and 200 or less. The molecular weight of the oxidation dye intermediate (A) means the molecular weight of each oxidation dye intermediate in the oxidation dye intermediate (A), and it is preferable that the molecular weights of the non-dissociated types of the components (A1), (A2), and (A3) are all within the above range. Furthermore, the molecular weight of the oxidative dye intermediate (A) in its non-dissociated form means the molecular weight of the oxidative dye intermediate (A) in its non-ionic state, even when the oxidative dye intermediate (A) is a salt, and does not include the molecular weight of the counter ion. This also includes cases where the oxidative dye intermediate (A) has an onium group such as a quaternary ammonium group, and in such cases, the counter ion is similarly not included in the molecular weight.

[0083] (Alkaline Agent) The alkaline agent used in the first agent may be either an inorganic alkaline agent or an organic alkaline agent. Examples of the alkaline agent include ammonia; alkanolamines such as mono-, di-, or trimethanolamine, mono-, di-, or triethanolamine; alkylamines such as methylamine, dimethylamine, ethylamine, diethylamine, N-methylethylamine, propylamine, and butylamine; aralkylamines such as benzylamine; and inorganic alkaline compounds such as sodium hydroxide and potassium hydroxide. One or more of these may be used. From the viewpoint of water solubility, the number of carbon atoms in the alkanolamine, alkylamine, or aralkylamine is preferably 10 or less, more preferably 8 or less. Among the above, from the viewpoint of efficiently penetrating the oxidation dye intermediate (A) into the interior of the fiber to further improve dyeability and fastness, the alkaline agent preferably contains one or more selected from the group consisting of ammonia, alkanolamine, alkylamine, aralkylamine, sodium hydroxide, and potassium hydroxide, and more preferably contains one or more selected from the group consisting of ammonia and alkanolamine.

[0084] (Water) The water used in the first agent is not particularly limited, and for example, ion-exchanged water, pure water, distilled water, etc. can be used.

[0085] (Other Components) In addition to the above-mentioned components, the first agent may contain antioxidants, fragrances, preservatives, thickeners, pH adjusters, surfactants, texture improvers, and the like.

[0086] (Content) The content of each component in the first agent is preferably within the following range: From the viewpoint of improving dyeability, the content of component (A) in the first agent is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, still more preferably 0.2% by mass or more, still more preferably 0.3% by mass or more, and still more preferably 0.5% by mass or more, and from the viewpoint of improving formulation stability, it is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and still more preferably 2.0% by mass or less. The content of component (A) in the first agent is preferably 0.01% by mass or more and 5.0% by mass or less, more preferably 0.02% by mass or more and 3.0% by mass or less, even more preferably 0.05% by mass or more and 3.0% by mass or less, still more preferably 0.1% by mass or more and 3.0% by mass or less, even more preferably 0.2% by mass or more and 3.0% by mass or less, still more preferably 0.3% by mass or more and 3.0% by mass or less, and still more preferably 0.5% by mass or more and 2.0% by mass or less.

[0087] From the viewpoint of improving dyeability, the total content of component (A1) and component (A2) in the first agent is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, still more preferably 0.2% by mass or more, and still more preferably 0.25% by mass or more, and from the viewpoint of improving formulation stability, it is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, still more preferably 1.5% by mass or less, and still more preferably 1.0% by mass or less. The total content of component (A1) and component (A2) in the first agent is preferably 0.01% by mass or more and 5.0% by mass or less, more preferably 0.02% by mass or more and 3.0% by mass or less, even more preferably 0.05% by mass or more and 2.0% by mass or less, still more preferably 0.1% by mass or more and 1.5% by mass or less, still more preferably 0.2% by mass or more and 1.5% by mass or less, and still more preferably 0.25% by mass or more and 1.0% by mass or less.

[0088] From the viewpoint of improving dyeability and fastness, the content of the alkaline agent in the first agent is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more. Furthermore, from the viewpoint of maintaining constant reactivity, it is preferably 10% by mass or less, more preferably 7.5% by mass or less, and even more preferably 5.0% by mass or less. The content of the alkaline agent in the first agent is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 7.5% by mass or less, even more preferably 0.5% by mass or more and 7.5% by mass or less, and even more preferably 1.0% by mass or more and 5.0% by mass or less. The content of the alkaline agent here refers to the effective amount of the alkaline agent.

[0089] The content of water in the first agent is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and preferably 99.98% by mass or less, from the viewpoint of improving the solubility of the oxidative dye intermediate (A) and the alkaline agent and from the viewpoint of improving the handleability when mixed with the second agent. The content of water in the first agent may be the balance of the oxidative dye intermediate (A) and the alkaline agent.

[0090] (pH) From the viewpoint of improving dyeability and fastness, the pH of the first agent is preferably 6 or more, more preferably 8 or more, and even more preferably 10 or more. Furthermore, from the viewpoint of maintaining constant reactivity, the pH is preferably 12.0 or less, more preferably 11.5 or less, and even more preferably 11.0 or less. The pH of the first agent is preferably 6 or more and 12.0 or less, more preferably 8 or more and 11.5 or less, and even more preferably 10 or more and 11.0 or less. The pH can be measured at 25°C by the method described in the examples.

[0091] (Dosage Form, Manufacturing Method) The dosage form of the first agent is not particularly limited, and can be liquid, paste, cream, gel, foam, spray, wax, or other dosage form depending on the product form, with liquid being preferred. The manufacturing method of the first agent is not particularly limited, and it can be manufactured by mixing the components by any method. The first agent of this embodiment can be preferably obtained by mixing a medium (e.g., water) with the dye and other components under heating (e.g., 60 to 80°C) to uniformly dissolve or disperse the dye and other components, and then adding an alkaline agent at room temperature and mixing uniformly.

[0092] <Second Agent> The second agent contains hydrogen peroxide and water. From the viewpoint of improving dyeability and fastness, the content of hydrogen peroxide in the second agent is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more. From the viewpoint of suppressing damage to fibers, the content of hydrogen peroxide is preferably 10% by mass or less, more preferably 8.0% by mass or less. The content of hydrogen peroxide in the second agent is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, and even more preferably 1.0% by mass or more and 8.0% by mass or less. From the viewpoint of handleability, hydrogen peroxide is preferably blended in the form of an aqueous solution. In this specification, the content of hydrogen peroxide in the second agent means an effective amount of hydrogen peroxide.

[0093] (Water) The water used in the second agent is not particularly limited, and for example, ion-exchanged water, pure water, distilled water, etc. can be used. From the viewpoint of improving handleability when mixed with the first agent, the content of water in the second agent is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and preferably 99.9% by mass or less. The content of water in the second agent includes the remainder of hydrogen peroxide.

[0094] (Other Components) In addition to the above components, the second agent may contain antioxidants, fragrances, preservatives, thickeners, pH adjusters, surfactants, texture improvers, and the like.

[0095] (pH) The pH of the second agent is preferably 2.5 or higher, more preferably 3.0 or higher, and preferably 6 or lower, more preferably 5 or lower, and even more preferably 4 or lower. The pH of the second agent is preferably 2.5 or higher and 6 or lower, more preferably 2.5 or higher and 5 or lower, and even more preferably 3.0 or higher and 4 or lower. The pH can be measured at 25°C by the method described in the examples.

[0096] (Dosage Form, Manufacturing Method) The dosage form of the second agent is not particularly limited, and can be liquid, paste, cream, gel, foam, spray, wax, or other dosage form depending on the product form, with liquid being preferred. The first agent and the second agent may be the same or different dosage forms, but from the viewpoint of ease of handling during use, it is preferable that they be the same dosage form. The manufacturing method of the second agent is not particularly limited, and examples include a method of mixing the respective components by any method. The second agent of this embodiment can preferably be obtained by mixing a medium (e.g., water) and other components under heating (e.g., 60 to 80°C) to dissolve them uniformly, and then adding hydrogen peroxide at room temperature and mixing them uniformly.

[0097] The composition of the present invention is prepared by mixing at least the first and second agents. Mixing may be performed at the time of use, or a mixture prepared in advance may be used. However, mixing is preferably performed at the time of use. The composition of the present invention may be prepared by mixing at least the first and second agents. For example, a third or more agents containing other components may be further mixed. The mixing ratio of the first and second agents varies depending on the concentrations of the oxidative dye intermediate (A) and alkaline agent in the first agent and the hydrogen peroxide in the second agent. However, the first agent:second agent (mass ratio) is preferably in the range of 1:0.1 to 1:10, more preferably 1:0.2 to 1:5, and even more preferably 1:0.5 to 1:3. After mixing the first and second agents, the pH may be further adjusted before use. The pH at 25° C. is preferably 3.0 or higher, more preferably 3.5 or higher, and even more preferably 4.0 or higher, and from the viewpoint of suppressing damage to fibers, is preferably 7.5 or lower, more preferably 7.0 or lower, and even more preferably 6.5 or lower. The pH of the composition after mixing the first and second parts is preferably 3.0 or higher and 7.5 or lower, more preferably 3.5 or higher and 7.0 or lower, and even more preferably 4.0 or higher and 6.5 or lower, at 25° C.

[0098] Furthermore, the mass ratio [[(A1) + (A2)] / hydrogen peroxide] of the total content of components (A1) and (A2) among the oxidative dye intermediates in the first agent to the hydrogen peroxide in the second agent is preferably 0.001 or more, more preferably 0.005 or more, even more preferably 0.01 or more, and even more preferably 0.03 or more, from the viewpoint of suppressing damage to fibers caused by hydrogen peroxide. Furthermore, from the viewpoint of improving dyeability and fastness, it is preferably 50 or less, more preferably 20 or less, even more preferably 5 or less, even more preferably 1.0 or less, and even more preferably 0.5 or less. That is, the mass ratio [[(A1) + (A2)] / hydrogen peroxide] is preferably 0.001 or more and 50 or less, more preferably 0.005 or more and 20 or less, even more preferably 0.01 or more and 5 or less, even more preferably 0.03 or more and 1.0 or less, and even more preferably 0.03 or more and 0.5 or less. The mass of hydrogen peroxide is the amount of active ingredient.

[0099] (Content) The content of each component in the dye composition for regenerated collagen fibers obtained by mixing at least the first agent and the second agent is preferably within the following range: From the viewpoint of improving dyeability, the content of component (A) or a reaction product of component (A) in the composition is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.02% by mass or more, still more preferably 0.03% by mass or more, still more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, and still more preferably 0.2% by mass or more, and from the viewpoint of improving formulation stability, it is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, and even more preferably 1.0% by mass or less. The content of component (A) or a reaction product of component (A) in the composition is preferably 0.005% by mass or more and 3.0% by mass or less, more preferably 0.01% by mass or more and 3.0% by mass or less, even more preferably 0.02% by mass or more and 3.0% by mass or less, still more preferably 0.03% by mass or more and 2.0% by mass or less, still more preferably 0.05% by mass or more and 2.0% by mass or less, still more preferably 0.1% by mass or more and 2.0% by mass or less, and still more preferably 0.2% by mass or more and 1.0% by mass or less.

[0100] From the viewpoint of improving dyeability and fastness, the content of the alkaline agent in the composition is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more. From the viewpoint of maintaining constant reactivity, it is preferably 5.0% by mass or less, more preferably 3.5% by mass or less, and even more preferably 2.5% by mass or less. The content of the alkaline agent in the composition is preferably 0.005% by mass or more and 5.0% by mass or less, more preferably 0.01% by mass or more and 3.5% by mass or less, even more preferably 0.1% by mass or more and 3.5% by mass or less, still more preferably 0.5% by mass or more and 3.5% by mass or less, and even more preferably 1.0% by mass or more and 2.5% by mass or less.

[0101] From the viewpoint of suppressing damage to fibers, the content of hydrogen peroxide in the composition is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, even more preferably 3.5% by mass or less, still more preferably 2.5% by mass or less, still more preferably 1.0% by mass or less, still more preferably 0.1% by mass or less, still more preferably 0.01% by mass or less, and still more preferably none.

[0102] The water content in the composition is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and preferably 99.9% by mass or less.

[0103] <Modified regenerated collagen fiber> The regenerated collagen fiber to be dyed with the dye composition of the present invention comprises modified regenerated collagen fiber containing one or more compounds (B) selected from the group consisting of the following components (B1) and (B2): (B1) benzoic acid or a salt thereof (B2) a copolymer containing structural units derived from an unsaturated monomer having a carboxy group and structural units derived from an aromatic vinyl compound, the copolymer having an acid value of 100 mg KOH / g or more and a weight-average molecular weight of 1,500 to 15,000, or a salt thereof

[0104] (Compound (B)) Compound (B) is one or more compounds selected from the group consisting of component (B1) and component (B2), and is a modifier for regenerated collagen fibers. The regenerated collagen fibers to be modified by compound (B) will be described later.

[0105] [Component (B1)] Component (B1) is benzoic acid or a salt thereof. When component (B1) is a salt, examples thereof include alkali metal salts such as sodium salts and potassium salts. Specific examples of component (B1) include one or more selected from the group consisting of benzoic acid, sodium benzoate, and potassium benzoate, and preferably one or more selected from the group consisting of benzoic acid and sodium benzoate.

[0106] [Component (B2)] Component (B2) is a copolymer containing structural units derived from an unsaturated monomer having a carboxy group and structural units derived from an aromatic vinyl compound, and is a copolymer or a salt thereof having an acid value of 100 mgKOH / g or more and a weight average molecular weight of 1,500 or more and 15,000 or less.

[0107] The structural unit derived from the unsaturated monomer having a carboxy group in component (B2) may be derived from an unsaturated monocarboxylic acid or an unsaturated dicarboxylic acid, or a combination thereof. Specific examples of the unsaturated monomer having a carboxy group include unsaturated monocarboxylic acids and unsaturated dicarboxylic acids. Examples of unsaturated monocarboxylic acids include acrylic acid, methacrylic acid, crotonic acid, oleic acid, and cyclopentenylacetic acid. Examples of unsaturated dicarboxylic acids include maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, and methylenesuccinic acid. Furthermore, an unsaturated dicarboxylic acid anhydride may be used as the unsaturated monomer having a carboxy group, and may be converted into an acid form by hydrolysis with an alkali or the like. Examples of unsaturated dicarboxylic acid anhydrides include maleic anhydride and citraconic anhydride. The unsaturated monomer having a carboxy group may be used alone or in combination of two or more.

[0108] The structural unit derived from an aromatic vinyl compound in component (B2) is not particularly limited as long as it is derived from an aromatic compound substituted with at least a vinyl group. Specific examples of aromatic vinyl compounds include styrene, α-methylstyrene, p-methylstyrene, 3-vinyltoluene, dimethylstyrene, ethylvinylbenzene, chloromethylstyrene, vinylnaphthalene, and vinylanthracene. The aromatic vinyl compounds can be used alone or in combination of two or more.

[0109] In component (B2), the bonding state of the monomers that give each structural unit may be block bonding, random bonding, or a combination thereof.

[0110] Component (B2) may contain structural units other than the above-mentioned unsaturated monomers. Examples of other structural units include, but are not limited to, structural units derived from unsaturated aliphatic hydrocarbon compounds. Examples of the unsaturated aliphatic hydrocarbon compounds include linear, branched, and cyclic unsaturated aliphatic hydrocarbon compounds. Examples of linear or branched unsaturated aliphatic hydrocarbon compounds include propylene, isobutylene, diisobutylene, triisobutylene, tripropylene, and tetrapropylene. Examples of cyclic unsaturated aliphatic hydrocarbon compounds include cyclopentene, cyclohexene, and cyclooctene. The structural units derived from the above-mentioned unsaturated aliphatic hydrocarbon compounds may include one or more types.

[0111] A preferred embodiment of component (B2) is, for example, a copolymer containing structural units derived from one or more selected from the group consisting of unsaturated monocarboxylic acids and unsaturated dicarboxylic acids and structural units derived from an aromatic vinyl compound. Specific examples of component (B2), from the viewpoint of further improving dyeability and fastness when dyeing with the dye composition of the present invention, preferably contain one or more selected from the group consisting of styrene-maleic acid copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, vinylbenzoic acid-maleic acid copolymer, vinylbenzoic acid-acrylic acid copolymer, vinylbenzoic acid-methacrylic acid copolymer, and styrene-4-vinylbenzoic acid copolymer, and more preferably contain styrene-maleic acid copolymer.

[0112] In component (B2), the molar ratio (u1 / u2) of the structural unit (u1) derived from the unsaturated monomer having a carboxy group to the structural unit (u2) derived from the aromatic vinyl compound monomer is preferably 1 / 5 to 5 / 1, more preferably 1 / 3 to 3 / 1, and even more preferably 1 / 2 to 2 / 1.

[0113] The acid value of component (B2) is 100 mgKOH / g or more, and from the viewpoint of further improving dyeability and fastness when dyed with the dye composition of the present invention, it is preferably 200 mgKOH / g or more, more preferably 300 mgKOH / g or more, even more preferably 400 mgKOH / g or more, and preferably 1000 mgKOH / g or less, more preferably 800 mgKOH / g or less, even more preferably 600 mgKOH / g or less. The acid value of component (B2) is preferably 100 mgKOH / g or more and 1000 mgKOH / g or less, more preferably 200 mgKOH / g or more and 800 mgKOH / g or less, even more preferably 200 mgKOH / g or more and 600 mgKOH / g or less, still more preferably 300 mgKOH / g or more and 600 mgKOH / g or less, still more preferably 400 mgKOH / g or more and 600 mgKOH / g or less. The acid value here refers to the number of milligrams of potassium hydroxide required to neutralize 1 g of sample.

[0114] Specific examples of component (B2) having an acid value within the above range include the following compounds: Styrene-maleic acid copolymer (styrene / maleic acid (molar ratio) = 1 / 1) 475 mg KOH / g Styrene-maleic acid copolymer (styrene / maleic acid (molar ratio) = 2 / 1) 355 mg KOH / g Styrene-maleic acid copolymer (styrene / maleic acid (molar ratio) = 3 / 1) 285 mg KOH / g

[0115] Component (B2) has a weight-average molecular weight of 1,500 or more and 15,000 or less, and from the viewpoint of further improving dyeability and fastness when dyed with the dye composition of the present invention, it is preferably 3,000 or more, more preferably 5,000 or more, even more preferably 6,000 or more, and preferably 10,000 or less, more preferably 9,500 or less, even more preferably 9,000 or less. The weight-average molecular weight of component (B2) is preferably 1,500 or more and 10,000 or less, more preferably 3,000 or more and 10,000 or less, even more preferably 5,000 or more and 9,500 or less, and even more preferably 6,000 or more and 9,000 or less. The weight-average molecular weight of component (B2) may also be preferably 3,000 or more and 15,000 or less, more preferably 5,000 or more and 15,000 or less, even more preferably 6,000 or more and 15,000 or less, and even more preferably 6,000 or more and 10,000 or less. In this specification, the term "weight average molecular weight" refers to a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC), and specifically can be measured by the method described in the examples.

[0116] The compound (B) can be used alone or in combination of two or more. Among the above, from the viewpoint of further improving dyeability and fastness when dyeing with the dye composition of the present invention, the compound (B) preferably contains one or more selected from the group consisting of benzoic acid, sodium benzoate, and a styrene-maleic acid copolymer, and more preferably contains a styrene-maleic acid copolymer.

[0117] (Content of Compound (B)) From the viewpoint of further improving dyeability and fastness when dyed with the dye composition of the present invention, the content of compound (B) in the modified regenerated collagen fiber is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, still more preferably 3.0% by mass or more, still more preferably 5.0% by mass or more, still more preferably 10% by mass or more, still more preferably 15% by mass or more, still more preferably 20% by mass or more, and is preferably 70% by mass or less, more preferably 65% ​​by mass or less, still more preferably 60% by mass or less, still more preferably 55% by mass or less, still more preferably 50% by mass or less, still more preferably 45% by mass or less, and still more preferably 40% by mass or less. The content of compound (B) in the modified regenerated collagen fiber is preferably 0.1% by mass or more and 70% by mass or less, more preferably 0.5% by mass or more and 65% by mass or less, even more preferably 1.0% by mass or more and 60% by mass or less, even more preferably 3.0% by mass or more and 55% by mass or less, even more preferably 5.0% by mass or more and 50% by mass or less, even more preferably 10% by mass or more and 45% by mass or less, even more preferably 15% by mass or more and 40% by mass or less, and even more preferably 20% by mass or more and 40% by mass or less.

[0118] When the modified regenerated collagen fiber contains component (B1) as compound (B), the content of component (B1) in the modified regenerated collagen fiber means the content converted into benzoic acid.

[0119] The content of component (B) in modified regenerated collagen fibers can be measured by the following method. First, an appropriate solvent that does not decompose component (B) and can dissolve the regenerated collagen fibers is selected, and the fibers are dissolved and extracted. Then, after appropriately diluting the extracted solution, the peak area of ​​a chromatogram plotted at an absorption wavelength suitable for quantifying component (B) is measured using HPLC / UV or GPC / UV, and the content of component (B) is calculated from the peak area. Specifically, the content of component (B) in modified regenerated collagen fibers can be measured by the method described in the Examples.

[0120] In the dye composition of the present invention, the mass ratio [(B) / (A)] of the compound (B) in the fiber for head accessories to the oxidative dye intermediate (A) in the dye composition may be controlled. For example, the mass ratio [(B) / (A)] of the compound (B) in the fiber for head accessories to the oxidative dye intermediate (A) in the dye composition is preferably 3 or more, more preferably 5 or more, and even more preferably 10 or more, from the viewpoints of the compatibility with the oxidative dye intermediate (A) and the storage stability and dye levelness of the dye composition; and from the viewpoints of dyeability and dye levelness, it is preferably 4000 or less, more preferably 2000 or less, even more preferably 1000 or less, even more preferably 500 or less, even more preferably 200 or less, even more preferably 100 or less, and even more preferably 50 or less. That is, the mass ratio [(B) / (A)] is preferably 3 or more and 4,000 or less, more preferably 3 or more and 2,000 or less, even more preferably 3 or more and 1,000 or less, still more preferably 5 or more and 500 or less, still more preferably 10 or more and 200 or less, still more preferably 20 or more and 100 or less, and still more preferably 20 or more and 50 or less.

[0121] (Component (C): Polyvalent Metal, or Salt or Complex Thereof) In order to firmly coordinate the compound (B) inside the fiber and further improve dyeability and fastness when dyed with the dye composition of the present invention, the modified regenerated collagen fiber preferably contains, in addition to the compound (B), a polyvalent metal, or a salt or complex thereof as component (C). Component (C) also acts as a modifier for the regenerated collagen fiber. Examples of component (C) include one or more polyvalent metals selected from the group consisting of calcium, magnesium, strontium, barium, zinc, chromium, aluminum, titanium, zirconium, tin, lead, antimony, iron, and copper, or a salt or complex thereof. These can be used alone or in combination of two or more. Among the above, from the viewpoint of improving water resistance and further improving dyeability and fastness when dyeing is performed using the dye composition of the present invention, component (C) preferably contains one or more polyvalent metals selected from the group consisting of aluminum, zirconium, and titanium, or a salt or complex thereof, and more preferably contains aluminum, or a salt or complex thereof.

[0122] When the modified regenerated collagen fibers contain component (C), the content of component (C) in the modified regenerated collagen fibers is, in terms of the amount of metal element, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, even more preferably 2% by mass or more, from the viewpoint of improving water resistance and further improving dyeability and fastness when dyed with the dye composition of the present invention. It is also preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less. The content of component (C) in the modified regenerated collagen fibers is preferably 0.1% by mass or more and 40% by mass or less, more preferably 0.5% by mass or more and 30% by mass or less, even more preferably 1.0% by mass or more and 20% by mass or less, and even more preferably 10% by mass or less. The amount of component (C) in the modified regenerated collagen fibers is quantified, for example, as follows: The modified regenerated collagen fibers are incinerated, alkali-fused, and dissolved in acid to prepare a solution. The solution is then appropriately diluted to prepare a measurement sample, and the metal element content is quantified using an ICP emission spectrometer. The metal element content can be specifically measured by the method described in the Examples.

[0123] In the dye composition of the present invention, the mass ratio [(C) / (A)] of component (C) in the fiber for head accessories to the oxidative dye intermediate (A) in the dye composition may be controlled. For example, the mass ratio [(C) / (A)] of component (C) in the fiber for head accessories to the oxidative dye intermediate (A) in the dye composition is preferably 0.3 or more, more preferably 0.5 or more, even more preferably 1.0 or more, and still more preferably 2 or more, from the viewpoints of the blendability of the oxidative dye intermediate (A) and the storage stability and dye levelness of the dye composition; and is preferably 500 or less, more preferably 200 or less, even more preferably 100 or less, still more preferably 50 or less, still more preferably 20 or less, and still more preferably 10 or less, from the viewpoints of dyeability and dye levelness. That is, the mass ratio [(C) / (A)] is preferably 0.3 or more and 500 or less, more preferably 0.3 or more and 200 or less, even more preferably 0.5 or more and 200 or less, still more preferably 0.5 or more and 100 or less, still more preferably 1.0 or more and 50 or less, still more preferably 2 or more and 20 or less, and still more preferably 2 or more and 10 or less.

[0124] (Method for manufacturing modified regenerated collagen fibers) The regenerated collagen fibers that are the raw material for modified regenerated collagen fibers do not need to be 100% collagen, and may contain natural or synthetic polymers or additives to improve quality. Furthermore, they may be post-processed regenerated collagen fibers. Filaments are preferred as the form of regenerated collagen fibers. Filaments are generally taken out from bobbins or boxes.

[0125] Suitable regenerated collagen fibers are artificially produced using collagen-derived polymers or oligomers as raw materials. Regenerated collagen fibers are usually produced by using a solubilized collagen raw material as a spinning dope, discharging this from a spinning nozzle into a coagulation bath to form fibers, and then drying the fibrous collagen in the final step. Here, regenerated collagen fibers before the drying step (hereinafter also referred to as "undried regenerated collagen fibers") can be produced by conventionally known methods. For example, undried regenerated collagen fibers can be obtained by discharging an aqueous collagen solution obtained by solubilizing insoluble collagen fibers made from the split hides of livestock animals through a spinning nozzle or slit, immersing the aqueous solution in an inorganic salt solution, and then recovering the resultant fibers without drying. This method will be specifically described below.

[0126] The collagen raw material used in the production of regenerated collagen fibers is preferably split skins. Split skins are obtained from fresh split skins obtained by slaughtering livestock animals such as cattle, or from salted raw hides. These split skins are mostly composed of insoluble collagen fibers, but are usually used after removing the fleshy part that is usually attached in a mesh-like form and removing the salt used to prevent spoilage and deterioration.

[0127] These insoluble collagen fibers contain impurities such as lipids (e.g., glycerides, phospholipids, and free fatty acids), glycoproteins, albumin, and other proteins other than collagen. These impurities have a significant effect on spinning stability, quality (e.g., gloss and strength and elongation), odor, and other factors during fiberization. Therefore, it is preferable to remove these impurities in advance by, for example, soaking the insoluble collagen fibers in lime to hydrolyze the fat in the fibers and loosen the collagen fibers, and then subjecting the fibers to conventional leather treatments such as acid / alkali treatment, enzyme treatment, and solvent treatment.

[0128] The insoluble collagen thus treated is then subjected to a solubilization treatment to cleave the cross-linked peptide moieties. As a method for such solubilization, a commonly used known alkali solubilization method, an enzyme solubilization method, etc., can be used. Furthermore, the alkali solubilization method and the enzyme solubilization method may be used in combination.

[0129] When the alkali solubilization method is applied, it is preferable to neutralize with an acid such as hydrochloric acid. Note that, as an improved version of the conventional alkali solubilization method, for example, the method described in JP-B-46-15033 may be used.

[0130] The enzymatic solubilization method has the advantage of being able to obtain solubilized collagen with a uniform molecular weight, and is a method that can be suitably employed in the present invention. Examples of such enzymatic solubilization methods that can be employed include those described in Japanese Patent Publication Nos. 43-25829 and 43-27513.

[0131] If the collagen that has been solubilized in this way is further subjected to operations such as pH adjustment, salting out, water washing, and solvent treatment, it is possible to obtain regenerated collagen fibers with excellent quality, and therefore it is preferable to perform these treatments.

[0132] Solubilized collagen is dissolved in an acid such as hydrochloric acid, acetic acid, or lactic acid to obtain a collagen aqueous solution having a pH of 2 to 4.5 and a collagen concentration of 1% by mass or more, preferably 2% by mass or more, and 15% by mass or less, preferably 10% by mass or less. The collagen aqueous solution may be degassed under reduced pressure and stirred, as needed, or filtered to remove water-insoluble fine particles. Furthermore, the collagen aqueous solution may contain appropriate amounts of additives such as stabilizers and water-soluble polymers, as needed, for purposes such as improving mechanical strength, water resistance and heat resistance, gloss, spinnability, coloration prevention, and preservative properties.

[0133] The collagen aqueous solution is extruded, for example, through a spinning nozzle or slit, and then immersed in an inorganic salt aqueous solution to obtain undried regenerated collagen fibers. Examples of the inorganic salt aqueous solution include aqueous solutions of water-soluble inorganic salts such as sodium sulfate, sodium chloride, and ammonium sulfate. Typically, the concentration of the inorganic salt in these inorganic salt aqueous solutions is adjusted to 10 to 40% by mass. The pH of the inorganic salt aqueous solution is preferably 2 or higher, more preferably 4 or higher, and preferably 13 or lower, more preferably 12 or lower. To adjust the pH, for example, metal salts such as sodium borate and sodium acetate, hydrochloric acid, boric acid, acetic acid, and sodium hydroxide can be used. When the pH of the inorganic salt aqueous solution is within the above range, the collagen peptide bonds are less susceptible to hydrolysis, making it easier to obtain the desired fibers. The temperature of the inorganic salt aqueous solution is not particularly limited, but is typically 35°C or lower, which prevents denaturation of soluble collagen, prevents a decrease in the strength of the spun fibers, and facilitates the production of stable threads. The lower limit of the temperature of the inorganic salt aqueous solution is not particularly limited, but can typically be adjusted appropriately depending on the solubility of the inorganic salt.

[0134] Undried regenerated collagen fibers may be pretreated (crosslinked) by immersion in an epoxy compound or a solution thereof. The amount of the epoxy compound is preferably 0.1 equivalents or more, more preferably 0.5 equivalents or more, and even more preferably 1 equivalent or more, relative to the amount of amino groups in the regenerated collagen fibers that can react with the epoxy groups of the epoxy compound, as measured by amino acid analysis, and is also preferably 500 equivalents or less, more preferably 100 equivalents or less, and even more preferably 50 equivalents or less. By using an epoxy compound in this range, the regenerated collagen fibers can be sufficiently insolubilized in water, and this is also preferable from an industrial handleability and environmental standpoint.

[0135] The epoxy compound may be used as is or dissolved in various solvents. Examples of solvents include water; alcohols such as methyl alcohol, ethyl alcohol, and isopropanol; ethers such as tetrahydrofuran and dioxane; halogenated organic solvents such as dichloromethane, chloroform, and carbon tetrachloride; and neutral organic solvents such as dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). These solvents may be used alone or in combination of two or more. When water is used as the solvent, an aqueous solution of an inorganic salt such as sodium sulfate, sodium chloride, or ammonium sulfate may be used as needed. Typically, the concentration of the inorganic salt in the aqueous solution is adjusted to 10 to 40% by mass. The pH of the aqueous solution may also be adjusted with, for example, a metal salt such as sodium borate or sodium acetate, or hydrochloric acid, boric acid, acetic acid, or sodium hydroxide. In this case, the pH of the aqueous solution is preferably 6 or higher, more preferably 8 or higher, from the viewpoint of preventing the reaction between the epoxy groups of the epoxy compound and the amino groups of collagen from slowing down and ensuring sufficient insolubilization in water. Furthermore, since the pH of an aqueous solution of an inorganic salt tends to decrease over time, a buffer may be used if necessary.

[0136] The temperature during treatment of undried regenerated collagen fibers with an epoxy compound is preferably 50°C or lower, from the viewpoints of preventing denaturation of the regenerated collagen fibers, preventing a decrease in the strength of the resulting fibers, and facilitating stable production of threads.

[0137] [Treatment with a fiber treating agent containing component (C)] From the viewpoint of improving water resistance, the modified regenerated collagen fibers used in the present invention preferably contain the component (C), and in producing the modified regenerated collagen fibers, it is preferable to treat the undried regenerated collagen fibers obtained by the above method in the following manner. First, the undried regenerated collagen fibers are immersed in a fiber treating agent containing component (C). The fiber treating agent containing component (C) is preferably an aqueous solution containing a polyvalent metal salt or polyvalent metal complex corresponding to component (C). The polyvalent metal salt or polyvalent metal complex preferably contains an aluminum salt or aluminum complex, and more preferably contains an aluminum salt. The aluminum salt is preferably basic aluminum chloride or basic aluminum sulfate represented by the following formula: Al(OH) n Cl 3-n , or Al2(OH) 2n (SO4) 3-n [wherein n is 0.5 to 2.5] Specific examples of the aluminum salt include aluminum sulfate, aluminum chloride, and alum, which can be used alone or in combination of two or more.

[0138] The content of the polyvalent metal salt and polyvalent metal complex in the fiber treatment agent is preferably 0.3 mass % or more and 5 mass % or less in terms of polyvalent metal oxide (aluminum oxide when the polyvalent metal is aluminum).

[0139] In order to prevent the polyvalent metal salt or polyvalent metal complex from being rapidly absorbed into the undried regenerated collagen fibers and causing uneven concentration, inorganic salts such as sodium chloride, sodium sulfate, and potassium chloride may be added to the fiber treatment agent as appropriate.

[0140] The pH of the fiber treatment agent at 25°C is preferably in the range of 2.5 or more and 5 or less, and can be adjusted using, for example, hydrochloric acid, sulfuric acid, acetic acid, sodium hydroxide, sodium carbonate, etc. A pH of 2.5 or more can suppress denaturation of the collagen structure, while a pH of 5 or less reduces the risk of precipitation of polyvalent metal salts or polyvalent metal complexes. It is preferable to initially adjust the pH to 2.2 or more and 3.5 or less to allow the aqueous solution of the polyvalent metal salt or polyvalent metal complex to sufficiently penetrate into the undried regenerated collagen fibers, and then add, for example, sodium hydroxide, sodium carbonate, etc. to adjust the pH to 3.5 or more and 5 or less to complete the treatment. When a highly basic polyvalent metal salt or polyvalent metal complex is used, only the initial pH adjustment of 2.5 or more and 5 or less is sufficient.

[0141] When treating with a fiber treatment agent containing component (C), the bath ratio of undried regenerated collagen fibers to the fiber treatment agent (dry mass of undried regenerated collagen fibers:mass of the fiber treatment agent) is preferably 1:2 to 1:500, more preferably 1:3 to 1:250, even more preferably 1:5 to 1:100, and even more preferably 1:20 to 1:50, when the mass of fibers after conditioning at 20°C and a relative humidity of 65% for 24 hours is taken as the dry mass.

[0142] The temperature during treatment with the fiber treatment agent containing component (C) (liquid temperature of the fiber treatment agent) is not particularly limited, but is preferably 5°C or higher, more preferably 10°C or higher, and is preferably 50°C or lower, more preferably 45°C or lower.

[0143] The treatment time (immersion time) with the fiber treatment agent containing component (C) is preferably 15 minutes or more, more preferably 30 minutes or more, even more preferably 1 hour or more, and even more preferably 3 hours or more, and is preferably 48 hours or less, more preferably 33 hours or less, and even more preferably 20 hours or less.

[0144] After treating the undried regenerated collagen fibers with an epoxy compound and / or the fiber treatment agent, the fibers may be washed with water, for example, by washing with running water for 10 minutes to 4 hours.

[0145] [Treatment with a fiber treatment agent containing component (B)] Regenerated collagen fibers, or undried regenerated collagen fibers obtained by treatment with a fiber treatment agent containing component (C), are treated with a fiber treatment agent containing component (B) to obtain modified regenerated collagen fibers that can be dyed with the dye composition of the present invention.

[0146] From the viewpoint of improving penetration into fibers and improving the treatment effect, the content of component (B) in the fiber treatment agent is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, still more preferably 2.5% by mass or more, still more preferably 3.0% by mass or more, and preferably 60% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less. The content of component (B) in the fiber treatment agent is preferably 0.3% by mass or more and 60% by mass or less, more preferably 0.5% by mass or more and 60% by mass or less, even more preferably 1.0% by mass or more and 40% by mass or less, still more preferably 2.5% by mass or more and 40% by mass or less, and still more preferably 3.0% by mass or more and 35% by mass or less.

[0147] When component (B1) is used as component (B), the content of component (B1) in the fiber treatment agent, calculated as benzoic acid, is even more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, even more preferably 20% by mass or more, and even more preferably 30% by mass or less, from the viewpoints of improving penetration into fibers and improving the treatment effect. When component (B1) is used as component (B), the content of component (B1) in the fiber treatment agent, calculated as benzoic acid, is preferably 0.3% by mass or more and 60% by mass or less, more preferably 0.5% by mass or more and 60% by mass or less, even more preferably 1.0% by mass or more and 40% by mass or less, still more preferably 2.5% by mass or more and 40% by mass or less, still more preferably 3.0% by mass or more and 35% by mass or less, still more preferably 5% by mass or more and 30% by mass or less, still more preferably 10% by mass or more and 30% by mass or less, still more preferably 15% by mass or more and 30% by mass or less, and still more preferably 20% by mass or more and 30% by mass or less.

[0148] When component (B2) is used as component (B), from the viewpoint of improving penetration into fibers and improving the treatment effect, the content of component (B2) in the fiber treatment agent is even more preferably 4% by mass or more, and even more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, and even more preferably 5% by mass or less. When component (B2) is used as component (B), the content of component (B2) in the fiber treatment agent is preferably 0.3% by mass or more and 60% by mass or less, more preferably 0.5% by mass or more and 60% by mass or less, even more preferably 1.0% by mass or more and 40% by mass or less, even more preferably 2.5% by mass or more and 40% by mass or less, even more preferably 3.0% by mass or more and 35% by mass or less, even more preferably 4% by mass or more and 30% by mass or less, even more preferably 4% by mass or more and 20% by mass or less, even more preferably 4.0% by mass or more and 10% by mass or less, and even more preferably 4% by mass or more and 5% by mass or less.

[0149] The fiber treatment agent containing component (B) preferably further contains a pH adjuster. The pH adjuster is not particularly limited as long as it can adjust the pH to the desired level, but examples thereof include alkalis such as sodium hydroxide and potassium hydroxide, and acids such as phosphoric acid, sulfuric acid, and hydrochloric acid.

[0150] The fiber treatment agent containing component (B) further contains water. The water content in the fiber treatment agent is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and still more preferably 70% by mass or more, and is preferably 99.7% by mass or less.

[0151] The pH of the fiber treatment agent containing component (B) at 25°C is preferably 3.0 or higher, more preferably 3.5 or higher, and even more preferably 4.0 or higher, from the viewpoint of suppressing damage to the fiber, and is preferably 7.5 or lower, more preferably 7.0 or lower, and even more preferably 6.5 or lower, from the viewpoint of suppressing damage to the fiber. The pH of the fiber treatment agent containing component (B) at 25°C is preferably 3.0 or higher and 7.5 or lower, more preferably 3.5 or higher and 7.0 or lower, and even more preferably 4.0 or higher and 6.5 or lower. The pH can be measured by the method described in the Examples.

[0152] Treatment with a fiber treatment agent containing component (B) can be carried out by immersing regenerated collagen fibers, or undried regenerated collagen fibers obtained by treatment with a fiber treatment agent containing component (C), in the fiber treatment agent containing component (B).

[0153] When treating with a fiber treatment agent containing component (B), the bath ratio of the regenerated collagen fibers or undried regenerated collagen fibers to the fiber treatment agent (dry mass of regenerated collagen fibers or undried regenerated collagen fibers:mass of the fiber treatment agent) is preferably 1:2 to 1:500, more preferably 1:3 to 1:250, even more preferably 1:5 to 1:100, and even more preferably 1:20 to 1:50, when the mass of the fibers after conditioning at 20°C and a relative humidity of 65% for 24 hours is taken as the dry mass.

[0154] The temperature during treatment with a fiber treatment agent containing component (B) (the temperature of the fiber treatment agent) is preferably 20°C or higher, more preferably 25°C or higher, and even more preferably 30°C or higher, from the viewpoint of improving penetration into fibers, and is preferably less than 100°C, more preferably 90°C or lower, even more preferably 80°C or lower, still more preferably 70°C or lower, and even more preferably 60°C or lower, from the viewpoint of suppressing damage to fibers. The temperature during treatment with a fiber treatment agent containing component (B) (the temperature of the fiber treatment agent) is preferably 20°C or higher and lower than 100°C, more preferably 20°C or higher and 90°C or lower, even more preferably 25°C or higher and 80°C or lower, still more preferably 25°C or higher and 70°C or lower, and even more preferably 30°C or higher and 60°C or lower. When treating with a fiber treatment agent by heating, the regenerated collagen fibers or undried regenerated collagen fibers may be immersed in the heated fiber treatment agent, or the fiber treatment agent may be heated after immersing the regenerated collagen fibers or undried regenerated collagen fibers in a low-temperature fiber treatment agent.

[0155] The treatment time (immersion time) with the fiber treatment agent containing component (B) is preferably 15 minutes or more, more preferably 30 minutes or more, even more preferably 1 hour or more, and still more preferably 3 hours or more from the viewpoint of improving the treatment effect, and is preferably 48 hours or less, more preferably 33 hours or less, and even more preferably 20 hours or less from the viewpoint of suppressing damage to the fiber. The treatment time (immersion time) with the fiber treatment agent containing component (B) is preferably 15 minutes to 48 hours, more preferably 30 minutes to 33 hours, even more preferably 1 hour to 20 hours, and still more preferably 3 hours to 20 hours.

[0156] Treatment with the fiber treatment agent containing component (B) is preferably carried out in an environment in which evaporation of water is suppressed. Specific means for suppressing evaporation of water include covering the container of the fiber treatment agent in which the fibers are immersed with a film-like substance, cap, lid, or the like made of a material that is impermeable to water vapor.

[0157] After treatment with the fiber treatment agent, the resulting modified regenerated collagen fibers are preferably washed with water, for example, by washing with running water for 10 minutes to 4 hours.

[0158] When component (B2) is used as component (B), the treatment with the fiber treatment agent containing component (B2) may be carried out two or more times. Specifically, it is preferable to carry out the following steps (1) and (2) in this order two or more times: (1) a step of immersing regenerated collagen fibers or undried regenerated collagen fibers obtained by treatment with the fiber treatment agent containing component (C) in a fiber treatment agent containing component (B2); and (2) a step of removing the fibers immersed in the fiber treatment agent in step (1) and washing them with water.

[0159] Here, from the viewpoint of improving the treatment effect, the treatment conditions for the first treatment and the second and subsequent treatments are more preferably in the following ranges. Other points are the same as those described above. In the first treatment, the pH at 25°C of the fiber treatment agent used in step (1) is preferably 4.5 or more, more preferably 5.0 or more, and preferably 7.5 or less, more preferably 7.0 or less, and even more preferably 6.5 or less, from the viewpoint of improving penetration into the fiber and suppressing damage to the fiber. Furthermore, in the first treatment, the pH at 25°C of the fiber treatment agent used in step (1) is preferably 4.5 or more and 7.5 or less, more preferably 5.0 or more and 7.0 or less, and even more preferably 5.0 or more and 6.5 or less. In the first treatment, the treatment time (immersion time) in step (1) is preferably 3 hours or more, more preferably 4 hours or more, and even more preferably 6 hours or more, from the viewpoint of improving the treatment effect. Furthermore, from the viewpoint of suppressing damage to the fiber, it is preferably 48 hours or less, more preferably 33 hours or less, and even more preferably 20 hours or less. In the first treatment, the treatment time (immersion time) in step (1) is preferably 3 hours or more and 48 hours or less, more preferably 4 hours or more and 33 hours or less, and even more preferably 6 hours or more and 20 hours or less.

[0160] In the second or subsequent treatments, the pH at 25°C of the fiber treatment agent used in step (1) is preferably 3.0 or more, more preferably 3.5 or more, and preferably 6.0 or less, more preferably 5.5 or less, even more preferably 5.0 or less, and still more preferably less than 4.5, from the viewpoint of improving the treatment effect. Furthermore, in the second or subsequent treatments, the pH at 25°C of the fiber treatment agent used in step (1) is preferably 3.0 or more and 6.0 or less, more preferably 3.0 or more and 5.5 or less, even more preferably 3.5 or more and 5.0 or less, and still more preferably 3.5 or more and less than 4.5. In the second or subsequent treatments, the treatment time (immersion time) in step (1) is preferably 15 minutes or more, more preferably 30 minutes or more, from the viewpoint of improving the treatment effect, and is preferably 5 hours or less, more preferably 3 hours or less, and still more preferably 2 hours or less, from the viewpoint of suppressing fiber damage. In the second and subsequent treatments, the treatment time (immersion time) in step (1) is preferably 15 minutes to 5 hours, more preferably 15 minutes to 3 hours, and even more preferably 30 minutes to 2 hours.

[0161] The number of treatments with the fiber treatment agent containing component (B2) is preferably 2 to 5 times, more preferably 2 to 3 times, from the viewpoint of improving the treatment effect and productivity. After the treatment, the resulting modified regenerated collagen fibers are preferably dried. The drying temperature is preferably 40°C or higher, more preferably 50°C or higher, from the viewpoint of improving the drying speed, and is preferably 100°C or lower, more preferably 80°C or lower, from the viewpoint of suppressing fiber damage. The drying time is preferably 15 minutes or longer, more preferably 30 minutes or longer, and is preferably 48 hours or shorter, more preferably 33 hours or shorter, even more preferably 20 hours or shorter, from the viewpoint of suppressing fiber damage.

[0162] By carrying out the above modification treatment, component (B) penetrates into the regenerated collagen fibers. Furthermore, when treatment is carried out with a fiber treatment agent containing component (C), component (B) is strongly coordinated to the polyvalent metal in the fibers. When modified regenerated collagen fibers are dyed using the dye composition of the present invention, the oxidation dye intermediate (A) and its reaction products interact with components (B) and (C) and are more likely to remain within the modified regenerated collagen fibers, which is thought to further improve fastness.

[0163] The regenerated collagen fibers to be dyed with the dye composition of the present invention may be fibers that contain at least a portion of the modified regenerated collagen fibers, or may be fibers consisting solely of modified regenerated collagen fibers. From the viewpoint of further improving fastness, the regenerated collagen fibers to be dyed with the dye composition of the present invention are preferably fibers consisting solely of modified regenerated collagen fibers.

[0164] [Dyeing method] The present invention provides a method for dyeing regenerated collagen fibers, the method comprising the following steps (I) and (II) in this order, and the regenerated collagen fibers comprise modified regenerated collagen fibers containing one or more compounds (B) selected from the group consisting of the following components (B1) and (B2):

[0165] Step (I): A step of preparing a dye composition for regenerated collagen fibers by mixing at least a first agent and a second agent, wherein the first agent contains an oxidation dye intermediate (A) containing one or more selected from the group consisting of the following components (A1) and (A2), an alkaline agent, and water, and the second agent contains hydrogen peroxide and water. Step (II): A step of applying the dye composition for regenerated collagen fibers to the regenerated collagen fibers.

[0166] (A1) One or more couplers selected from the group consisting of couplers (A1-1) having a benzene ring, electron-donating groups at the 1st and 3rd positions on the benzene ring, and hydrogen atoms at the 4th and 6th positions; couplers (A1-2) having a pyridine ring, electron-donating groups at the 2nd and 6th positions on the pyridine ring, and hydrogen atoms at the 3rd and 5th positions; and couplers (A1-3) represented by the following general formula (A13):

[0167]

[0168] (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group, or an electron-donating group.

[0169] (A2) One or more couplers other than the component (A1), selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions.

[0170] (B1) Benzoic acid or a salt thereof. (B2) A copolymer containing a structural unit derived from an unsaturated monomer having a carboxy group and a structural unit derived from an aromatic vinyl compound, the copolymer having an acid value of 100 mgKOH / g or more and a weight average molecular weight of 1,500 or more and 15,000 or less, or a salt thereof.

[0171] In the following description, the method for dyeing regenerated collagen fibers will also be simply referred to as the "dyeing method of the present invention."

[0172] <Step (I)> In step (I), a dye composition for regenerated collagen fibers is prepared by mixing at least a first agent and a second agent, wherein the first agent contains an oxidation dye intermediate (A) containing one or more selected from the group consisting of the following components (A1) and (A2), an alkaline agent, and water, and the second agent contains hydrogen peroxide and water. (A1) One or more couplers selected from the group consisting of couplers having a benzene ring, electron donating groups at the 1st and 3rd positions on the benzene ring, and hydrogen atoms at the 4th and 6th positions, and couplers having a pyridine ring, electron donating groups at the 2nd and 6th positions on the pyridine ring, and hydrogen atoms at the 3rd and 5th positions; (A2) One or more couplers selected from the group consisting of couplers having a benzene ring, electron donating groups at the 1st and 2nd positions on the benzene ring, and hydrogen atoms at two or more of the 3rd to 6th positions, and couplers having a pyridine ring, electron donating groups at the 2nd and 3rd positions on the pyridine ring, and hydrogen atoms at two or more of the 4th to 6th positions.

[0173] The first and second agents, their mixing ratios, and preferred embodiments are the same as those described in the stain composition for regenerated collagen fibers.

[0174] <Step (II)> In step (II), the regenerated collagen fiber dye composition is applied to the regenerated collagen fibers, which include modified regenerated collagen fibers containing one or more compounds (B) selected from the group consisting of the following components (B1) and (B2):

[0175] (B1) Benzoic acid or a salt thereof. (B2) A copolymer containing a structural unit derived from an unsaturated monomer having a carboxy group and a structural unit derived from an aromatic vinyl compound, the copolymer having an acid value of 100 mgKOH / g or more and a weight average molecular weight of 1,500 or more and 15,000 or less, or a salt thereof.

[0176] The modified regenerated collagen fibers and compound (B) and their preferred embodiments are the same as those described above.

[0177] The method for applying the dye composition for regenerated collagen fibers to regenerated collagen fibers may be any method that allows the dye composition to come into contact with the regenerated collagen fibers, and examples include a method of applying the composition to dry or wet regenerated collagen fibers, and a method of immersing the regenerated collagen fibers in the composition. Among these, a method of applying the dye composition to dry regenerated collagen fibers is preferred. From the viewpoint of a balance between dyeability, fastness, and economy, the amount of the dye composition applied to the regenerated collagen fibers is preferably a bath ratio (dry mass of regenerated collagen fibers:mass of dye composition) of 1:0.2 to 1:500, where the mass of the fibers after conditioning at 20°C and a relative humidity of 65% for 24 hours is taken as the dry mass. When the dye composition is applied to the regenerated collagen fibers, the amount of the dye composition applied to the regenerated collagen fibers, from the viewpoint of a balance between dyeability and economic efficiency, is preferably 1:0.2 to 1:200, even more preferably 1:0.2 to 1:100, even more preferably 1:0.2 to 1:50, even more preferably 1:0.2 to 1:20, even more preferably 1:0.5 to 1:10, even more preferably 1:0.5 to 1:5, and even more preferably 1:0.8 to 1:3. When the regenerated collagen fibers are immersed in the dye composition, the bath ratio (dry mass of the regenerated collagen fibers:mass of the dye composition) is more preferably 1:2 to 1:500, even more preferably 1:3 to 1:250, even more preferably 1:5 to 1:100, even more preferably 1:10 to 1:50, and even more preferably 1:10 to 1:20.

[0178] In step (II), the dyeing conditions for the fiber for headwear may be set using the mass ratio [(B) / (A)] of the compound (B) in the fiber for headwear to the oxidative dye intermediate (A) in the dye composition as an index. Specifically, for example, step (II) may be carried out under conditions such that the mass ratio [(B) / (A)] of the compound (B) in the fiber for headwear to the oxidative dye intermediate (A) in the dye composition is preferably 3 or more, more preferably 5 or more, and even more preferably 10 or more, from the viewpoints of the compatibility of the oxidative dye intermediate (A) and the storage stability and dye levelness of the dye composition; and is preferably 4000 or less, more preferably 2000 or less, even more preferably 1000 or less, even more preferably 500 or less, even more preferably 200 or less, even more preferably 100 or less, and even more preferably 50 or less, from the viewpoints of dyeability and dye levelness. That is, the mass ratio [(B) / (A)] is preferably 3 or more and 4,000 or less, more preferably 3 or more and 2,000 or less, even more preferably 3 or more and 1,000 or less, still more preferably 5 or more and 500 or less, still more preferably 10 or more and 200 or less, still more preferably 20 or more and 100 or less, and still more preferably 20 or more and 50 or less. Furthermore, the dyeing conditions for the fiber for head ornaments can also be set using the mass ratio [(C) / (A)] of component (C) in the fiber for head ornaments to the oxidation dye intermediate (A) in the dye composition as an index. Specifically, for example, the mass ratio [(C) / (A)] of component (C) in the fiber for head accessories to the oxidation dye intermediate (A) in the dye composition is preferably 0.3 or more, more preferably 0.5 or more, even more preferably 1.0 or more, and still more preferably 2 or more, from the viewpoints of the blendability of the oxidation dye intermediate (A) and the storage stability and dye levelness of the dye composition, and from the viewpoints of dyeability and dye levelness, it can also be carried out under conditions such that it is preferably 500 or less, more preferably 200 or less, even more preferably 100 or less, still more preferably 50 or less, still more preferably 20 or less, and still more preferably 10 or less. That is, the mass ratio [(C) / (A)] is preferably 0.3 or more and 500 or less, more preferably 0.3 or more and 200 or less, even more preferably 0.5 or more and 200 or less, still more preferably 0.5 or more and 100 or less, still more preferably 1.0 or more and 50 or less, still more preferably 2 or more and 20 or less, and still more preferably 2 or more and 10 or less.

[0179] In step (II), when the dye composition is applied to the regenerated collagen fibers, the application time is preferably 10 seconds or more, more preferably 20 seconds or more, from the viewpoint of further improving dyeability and fastness, and preferably 10 minutes or less, more preferably 5 minutes or less, from the viewpoint of improving productivity. The application time when the dye composition is applied to the regenerated collagen fibers is preferably 10 seconds to 10 minutes, more preferably 20 seconds to 5 minutes. In step (II), after the dye composition is applied to the regenerated collagen fibers, it is preferable to further perform a step of leaving the fibers standing. In this case, the leaving time is preferably 1 minute or more, more preferably 3 minutes or more, and even more preferably 5 minutes or more, from the viewpoint of further improving dyeability and fastness, and preferably 1 hour or less, more preferably 30 minutes or less, from the viewpoint of improving productivity. The leaving time after applying the dye composition to the regenerated collagen fibers is preferably 1 minute to 1 hour, more preferably 3 minutes to 30 minutes, and even more preferably 5 minutes to 30 minutes.

[0180] When regenerated collagen fibers are immersed in the dye composition, the immersion time is preferably 10 seconds or more, more preferably 30 seconds or more, from the viewpoint of further improving dyeability and fastness, and is preferably 3 hours or less, more preferably 2 hours or less, and even more preferably 1 hour or less, from the viewpoint of improving productivity. When regenerated collagen fibers are immersed in the dye composition, the immersion time is preferably 10 seconds or more and 3 hours or less, more preferably 10 seconds or more and 2 hours or less, and even more preferably 30 seconds or more and 1 hour or less.

[0181] The temperature at which step (II) is carried out is not particularly limited, but from the viewpoint of improving the handleability of the dye composition and suppressing thermal shrinkage of the regenerated collagen fibers, it is preferably 40°C or lower, more preferably 35°C or lower. Furthermore, from the viewpoint of further improving dyeability and fastness, it is preferably 5°C or higher, more preferably 10°C or higher. The temperature at which the dye composition is applied to the regenerated collagen fibers is preferably 5°C or higher and 40°C or lower, more preferably 10°C or higher and 35°C or lower.

[0182] (Rinsing step) The dyeing method of the present invention preferably includes a step of rinsing the dye composition applied to the regenerated collagen fibers after step (II) (hereinafter also simply referred to as the "rinsing step"). The rinsing step is carried out, for example, by washing the dye composition applied to the regenerated collagen fibers with water. There are no particular restrictions on the temperature of the water, but warm water at 35 to 45°C is preferred.

[0183] (Drying Step) The dyeing method of the present invention preferably includes a step of drying the regenerated collagen fibers (hereinafter also simply referred to as a "drying step") after applying the dye composition to the regenerated collagen fibers, or after performing a rinsing step if one is included. The step of drying the regenerated collagen fibers is a step of reducing the moisture content of the regenerated collagen fibers, and includes, for example, towel drying, drying with a dryer (cold air or hot air), air drying, and a combination of two or more of these drying treatments in order to actively reduce the moisture content of the regenerated collagen fibers.

[0184] [Colored modified regenerated collagen fiber] The present invention further provides a colored modified regenerated collagen fiber containing the following components (A0) and (B): (A0) A reaction product of an oxidation dye intermediate (A) containing at least one selected from the group consisting of the following components (A1) and (A2): (A1) At least one selected from the group consisting of a coupler (A1-1) having a benzene ring, electron-donating groups at the 1st and 3rd positions on the benzene ring, and hydrogen atoms at the 4th and 6th positions, a coupler (A1-2) having a pyridine ring, electron-donating groups at the 2nd and 6th positions on the pyridine ring, and hydrogen atoms at the 3rd and 5th positions, and a coupler (A1-3) represented by the following general formula (A13):

[0185]

[0186] (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group, or an electron-donating group.

[0187] (A2) one or more couplers other than the component (A1), selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions. (B) one or more compounds selected from the group consisting of the following components (B1) and (B2): (B1) benzoic acid or a salt thereof; (B2) a copolymer containing structural units derived from an unsaturated monomer having a carboxy group and structural units derived from an aromatic vinyl compound, having an acid value of 100 mgKOH / g or more and a weight-average molecular weight of 1,500 to 15,000, or a salt thereof.

[0188] The colored and modified regenerated collagen fibers are modified regenerated collagen fibers that have been modified with the component (B) and then colored with the component (A0). From the viewpoint of further improving dyeability and fastness, the colored and modified regenerated collagen fibers preferably further contain the component (C): a polyvalent metal, or a salt or complex thereof.

[0189] The colored modified regenerated collagen fibers can be obtained by preparing modified regenerated collagen fibers containing one or more compounds (B) selected from the group consisting of component (B1) and component (B2) using the method described above, and then applying the regenerated collagen fiber dye composition to the modified regenerated collagen fibers to dye them. The dyeing method of the present invention described above can be preferably used as a method for dyeing the modified regenerated collagen fibers.

[0190] The colored modified regenerated collagen fiber of the present invention preferably has a controlled mass ratio [(B) / (A)] of the compound (B) in the fiber for headwear to the oxidative dye intermediate (A) in the dye composition. That is, the mass ratio [(B) / (A)] of the compound (B) in the fiber for headwear to the oxidative dye intermediate (A) in the dye composition is preferably 3 or more, more preferably 5 or more, and even more preferably 10 or more, from the viewpoints of compatibility with the oxidative dye intermediate (A) and the storage stability and dye levelness of the dye composition. Furthermore, from the viewpoints of dyeability and dye levelness, it is preferably 4000 or less, more preferably 2000 or less, even more preferably 1000 or less, even more preferably 500 or less, even more preferably 200 or less, even more preferably 100 or less, even more preferably 50 or less. That is, the mass ratio [(B) / (A)] is preferably 3 or more and 4,000 or less, more preferably 3 or more and 2,000 or less, even more preferably 3 or more and 1,000 or less, still more preferably 5 or more and 500 or less, still more preferably 10 or more and 200 or less, still more preferably 20 or more and 100 or less, and still more preferably 20 or more and 50 or less.

[0191] Furthermore, the colored modified regenerated collagen fibers of the present invention preferably have a controlled mass ratio [(C) / (A)] of component (C) in the fiber for head accessories to the oxidative dye intermediate (A) in the dye composition. That is, the mass ratio [(C) / (A)] of component (C) in the fiber for head accessories to the oxidative dye intermediate (A) in the dye composition is preferably 0.3 or more, more preferably 0.5 or more, even more preferably 1.0 or more, and still more preferably 2 or more, from the viewpoints of compatibility with the oxidative dye intermediate (A) and the storage stability and dye levelness of the dye composition; and from the viewpoints of dyeability and dye levelness, it is preferably 500 or less, more preferably 200 or less, even more preferably 100 or less, still more preferably 50 or less, even more preferably 20 or less, and still more preferably 10 or less. That is, the mass ratio [(C) / (A)] is preferably 0.3 or more and 500 or less, more preferably 0.3 or more and 200 or less, even more preferably 0.5 or more and 200 or less, still more preferably 0.5 or more and 100 or less, still more preferably 1.0 or more and 50 or less, still more preferably 2 or more and 20 or less, and still more preferably 2 or more and 10 or less.

[0192] [Fiber for head accessories, head accessories] The present invention further provides a fiber for head accessories containing the colored modified regenerated collagen fiber, and a head accessory containing the fiber. The colored modified regenerated collagen fiber can be suitably used as a fiber for head accessories. In this specification, "head accessories" refers to, for example, hair wigs, hairpieces, weaving, hair extensions, braided hair, hair accessories, doll hair, etc. Furthermore, "fiber for head accessories" refers to fibers used in the head accessories. In this application, fibers for head accessories also include human hair. The head accessory may contain at least a portion of the colored modified regenerated collagen fiber, and may contain both colored regenerated collagen fiber and human hair.

[0193] In relation to the above-described embodiment, the present invention discloses the following: <1> A dye composition for regenerated collagen fibers, which uses a mixture of at least a first agent and a second agent, wherein the first agent is an oxidation dye intermediate (A) containing one or more selected from the group consisting of the following components (A1) and (A2): (A1) one or more selected from the group consisting of a coupler (A1-1) having a benzene ring, electron-donating groups at the 1st and 3rd positions on the benzene ring, and hydrogen atoms at the 4th and 6th positions, a coupler (A1-2) having a pyridine ring, electron-donating groups at the 2nd and 6th positions on the pyridine ring, and hydrogen atoms at the 3rd and 5th positions, and a coupler (A1-3) represented by the following general formula (A13): (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26are each independently a hydrogen atom, an alkyl group, or an electron-donating group. ) (A2) one or more couplers other than the component (A1), selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and at least two of the 3- to 6-positions having hydrogen atoms, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and at least two of the 4- to 6-positions having hydrogen atoms, an alkaline agent, and water, wherein the second agent contains hydrogen peroxide and water, and the regenerated collagen fibers are one or more compounds (B) selected from the group consisting of the following components (B1) and (B2): (B1) benzoic acid or a salt thereof, (B2) a copolymer or salt thereof containing a structural unit derived from an unsaturated monomer having a carboxy group and a structural unit derived from an aromatic vinyl compound, the copolymer having an acid value of 100 mg KOH / g or more and a weight average molecular weight of 1,500 to 15,000, <2> The dye composition for regenerated collagen fibers according to <1>, wherein the coupler (A1-1) preferably contains a compound represented by the following general formula (A11) or a salt thereof: (In formula (A11), R 1 is an electron donating group attached to the carbon atom at the 1st position, R 2 represents a hydrogen atom, an alkyl group or an electron-donating group bonded to the carbon atom at the 2-position, R 3 is an electron donating group attached to the 3-position carbon, R 4 is a hydrogen atom, an alkyl group, or an electron-donating group bonded to the carbon atom at the 5-position. 2 and R 3may be bonded to each other to form a hydrocarbon ring structure having aromaticity.) <3> The electron-donating group in the general formula (A11) preferably contains one or more selected from the group consisting of a hydroxy group, a hydroxyalkyl group, an alkoxy group, a hydroxyalkoxy group, a primary to tertiary amino group, an alkylamino group, and a hydrocarbon ring structure having aromaticity, more preferably contains one or more selected from the group consisting of a hydroxy group, a hydroxyalkyl group having from 2 to 8 carbon atoms, an alkoxy group having from 1 to 8 carbon atoms, a hydroxyalkoxy group having from 2 to 8 carbon atoms, a primary amino group (—NH2), and an alkylamino group having from 1 to 8 carbon atoms, even more preferably contains one or more selected from the group consisting of a hydroxy group and a primary amino group (—NH2), the alkyl group preferably contains an alkyl group having from 1 to 8 carbon atoms, more preferably an alkyl group having from 1 to 3 carbon atoms, even more preferably a methyl group, the hydrocarbon ring structure having aromaticity is 2 and R 3 are bonded to each other to form an aromatic hydrocarbon ring structure, the ring structure preferably contains an aromatic hydrocarbon ring structure having 5 to 8 ring carbon atoms, more preferably contains an aromatic hydrocarbon ring structure having 5 to 6 ring carbon atoms, and even more preferably contains an aromatic hydrocarbon ring structure having 6 ring carbon atoms. 1 is preferably a hydroxy group or a primary amino group (—NH), and R 2 is preferably a hydrogen atom or a methyl group, and R 3 is preferably a hydroxy group or a primary amino group (—NH), or R 2 and R 3 are bonded to each other to form an aromatic hydrocarbon ring structure having 6 ring carbon atoms, and R 4is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom. <5> The dye composition for regenerated collagen fibers according to any one of <2> to <4>, wherein the compound represented by general formula (A11) includes one or more compounds selected from the group consisting of meta-aminophenol, resorcinol, meta-phenylenediamine, 2-methylresorcinol, 1-naphthol, and salts thereof, and preferably includes one or more compounds selected from the group consisting of meta-aminophenol, resorcinol, 2-methylresorcinol, 1-naphthol, and salts thereof. <6> The dye composition for regenerated collagen fibers according to any one of <1> to <5>, wherein the coupler (A1-2) preferably includes a compound represented by the following general formula (A12) or a salt thereof: (In formula (A12), R 5 is an electron donating group attached to the 2-position carbon, R 6 represents a hydrogen atom, an alkyl group or an electron-donating group bonded to the carbon atom at the 4-position, R 7 is an electron-donating group bonded to the carbon at the 6-position.) <7> The dye composition for regenerated collagen fibers according to <6>, wherein the electron-donating group in the general formula (A12) preferably includes one or more selected from the group consisting of a hydroxy group, a hydroxyalkyl group, an alkoxy group, a hydroxyalkoxy group, a primary to tertiary amino group, and an alkylamino group, more preferably includes one or more selected from the group consisting of a hydroxy group, a hydroxyalkyl group having from 2 to 8 carbon atoms, an alkoxy group having from 1 to 8 carbon atoms, a hydroxyalkoxy group having from 2 to 8 carbon atoms, a primary amino group (-NH2), and an alkylamino group having from 1 to 8 carbon atoms, even more preferably includes one or more selected from the group consisting of a hydroxy group and a primary amino group (-NH2), and the alkyl group preferably includes an alkyl group having from 1 to 8 carbon atoms, more preferably an alkyl group having from 1 to 3 carbon atoms, even more preferably a methyl group. <8> In the general formula (A12), R 5 is preferably a hydroxy group or a primary amino group (—NH), and R 6 is preferably a hydrogen atom or a methyl group, and R 7<9> The dye composition for regenerated collagen fibers according to any one of <6> to <8>, wherein the compound represented by the general formula (A12) contains 2,6-diaminopyridine or a salt thereof. <10> In the general formula (A13), R 11 n in R is preferably 2 or more and 8 or less, more preferably 2 or more and 4 or less, 12 , R 14 , R 22 and R 24 The electron donating group in R preferably comprises a hydroxy group or a primary amino group (—NH), more preferably a primary amino group (—NH); 13 , R 16 , R 23 and R 26 The dye composition for regenerated collagen fibers according to any one of <1> to <9>, wherein preferably contains a hydrogen atom or a methyl group, and more preferably is a hydrogen atom.

[0194] <11> The dye composition for regenerated collagen fibers according to any one of <1> to <10>, wherein the coupler represented by the general formula (A13) comprises 1,3-bis(2,4-diaminophenoxy)propane or a salt thereof. <12> The dye composition for regenerated collagen fibers according to any one of <1> to <11>, wherein the component (A1) preferably comprises one or more selected from the group consisting of meta-aminophenol, resorcinol, meta-phenylenediamine, 2-methylresorcinol, 1-naphthol, 2,6-diaminopyridine, 1,3-bis(2,4-diaminophenoxy)propane, and salts thereof, and more preferably comprises one or more selected from the group consisting of meta-aminophenol, resorcinol, 2-methylresorcinol, 1-naphthol, and salts thereof. <13> The dye composition for regenerated collagen fibers according to any one of <1> to <12>, wherein the coupler (A2-1) preferably contains a compound represented by the following general formula (A21) or a salt thereof (however, couplers corresponding to the component (A1) are excluded): (In formula (A21), R 31 is an electron donating group attached to the carbon atom at the 1st position, R 32is an electron donating group attached to the 2-position carbon, R 33 ~R 36 are hydrogen atoms, alkyl groups, or electron-donating groups bonded to the 3-, 4-, 5-, and 6-position carbons, respectively. 33 ~R 36 and two or more of the above are hydrogen atoms.) <14> The dye composition for regenerated collagen fibers according to <13>, wherein the electron-donating group in the general formula (A21) preferably includes one or more selected from the group consisting of a hydroxy group, a hydroxyalkyl group, an alkoxy group, a hydroxyalkoxy group, a primary to tertiary amino group, and an alkylamino group, more preferably includes one or more selected from the group consisting of a hydroxy group, a hydroxyalkyl group having from 2 to 8 carbon atoms, an alkoxy group having from 1 to 8 carbon atoms, a hydroxyalkoxy group having from 2 to 8 carbon atoms, a primary amino group (-NH2), and an alkylamino group having from 1 to 8 carbon atoms, even more preferably includes one or more selected from the group consisting of a hydroxy group, a hydroxyalkoxy group having from 2 to 8 carbon atoms, and a primary amino group (-NH2), and the alkyl group preferably includes an alkyl group having from 1 to 8 carbon atoms, more preferably an alkyl group having from 1 to 3 carbon atoms, and even more preferably a methyl group. <15> The dye composition for regenerated collagen fibers according to <13>, wherein in the general formula (A21), R 31 is preferably a hydroxy group, a hydroxyalkoxy group having from 2 to 8 carbon atoms, or a primary amino group (—NH), more preferably a hydroxy group, a hydroxyethoxy group, or a primary amino group (—NH); R 32 is preferably a hydroxy group or a primary amino group (-NH2), more preferably a primary amino group (-NH2). <16> The dye composition for regenerated collagen fibers according to any one of <13> to <15>, wherein the compound represented by general formula (A21) comprises one or more members selected from the group consisting of orthoaminophenol, 2,4-diaminophenoxyethanol, and salts thereof. <17> The dye composition for regenerated collagen fibers according to any one of <1> to <16>, wherein the coupler (A2-2) preferably comprises a compound represented by the following general formula (A22) or a salt thereof: (In formula (A22), R 37 is an electron donating group attached to the 2-position carbon, R 38 is an electron donating group attached to the 3-carbon atom. 39 ~R 41 are hydrogen atoms, alkyl groups, or electron-donating groups bonded to the 4-, 5-, and 6-position carbons, respectively. 39 ~R 41 In the general formula (A22), two or more of R 37 is preferably a hydroxy group or a primary amino group (—NH), and R 38 is preferably a hydroxy group or a primary amino group (—NH), more preferably a primary amino group (—NH), and R 39 ~R 41 are each independently preferably a hydrogen atom or a methyl group, more preferably R 39 ~R 41 <19> The dye composition for regenerated collagen fibers according to <17> or <18>, wherein the compound represented by general formula (A22) contains 2,3-diaminopyridine, 2-amino-3-hydroxypyridine, or a salt thereof. <20> The dye composition for regenerated collagen fibers according to any one of <1> to <19>, wherein the component (A2) preferably contains a coupler (A2-1), more preferably one or more selected from the group consisting of ortho-aminophenol, 2,4-diaminophenoxyethanol, and salts thereof.

[0195] <21> The dye composition for regenerated collagen fibers according to any one of <1> to <20>, wherein the oxidation dye intermediate (A) preferably contains component (A1), more preferably contains one or more selected from the group consisting of meta-aminophenol, resorcinol, meta-phenylenediamine, 2-methylresorcinol, 1-naphthol, 2,6-diaminopyridine, 1,3-bis(2,4-diaminophenoxy)propane, and salts thereof. <22> The dye composition for regenerated collagen fibers according to any one of <1> to <20>, wherein the oxidation dye intermediate (A) preferably contains coupler (A1-1), more preferably contains one or more selected from the group consisting of meta-aminophenol, resorcinol, 2-methylresorcinol, 1-naphthol, and salts thereof. <23> The dye composition for regenerated collagen fibers according to any one of <1> to <22>, wherein the total content of component (A1) and component (A2) in the oxidative dye intermediate (A) is preferably 30% by mass or more, more preferably 40% by mass or more, and may be 100% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less. <24> The dye composition for regenerated collagen fibers according to any one of <1> to <23>, wherein the content of component (A1) in the oxidative dye intermediate (A) is preferably 30% by mass or more, more preferably 40% by mass or more, and may be 100% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less. <25> The dye composition for regenerated collagen fibers according to any one of <1> to <24>, wherein the oxidation dye intermediate (A) further contains component (A3): precursor, and the precursor contains one or more members selected from the group consisting of paraphenylenediamine, toluene-2,5-diamine, orthochloroparaphenylenediamine, N-phenylparaphenylenediamine, N,N-bis(hydroxyethyl)paraphenylenediamine, 3-methyl-4-aminophenol, 2-hydroxyethylparaphenylenediamine, paraaminophenol, paramethylaminophenol, 4-amino-metacresol, and salts thereof, preferably one or more members selected from the group consisting of toluene-2,5-diamine, paraaminophenol, 4-amino-metacresol, 1-hydroxyethyl-4,5-diaminopyrazole, and salts thereof.<26> The dye composition for regenerated collagen fibers according to <25>, wherein the content of component (A3) in the oxidative dye intermediate (A) is preferably 20% by mass or more and 70% by mass or less, more preferably 30% by mass or more and 65% by mass or less, and even more preferably 40% by mass or more and 60% by mass or less. <27> The dye composition for regenerated collagen fibers according to any one of <1> to <26>, wherein the content of couplers other than component (A1) and component (A2) in the oxidative dye intermediate (A) is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, still more preferably 5% by mass or less, still more preferably 2% by mass or less, and may even be 0% by mass. <28> The dye composition for regenerated collagen fibers according to any one of <1> to <27>, wherein the molecular weight of the oxidative dye intermediate (A) as a non-dissociated type is preferably 95 to 500, more preferably 100 to 300, and even more preferably 105 to 200. <29> The dye composition for regenerated collagen fibers according to any one of <1> to <28>, wherein the alkaline agent preferably comprises one or more selected from the group consisting of ammonia, alkanolamines, alkylamines, aralkylamines, sodium hydroxide, and potassium hydroxide, and more preferably comprises one or more selected from the group consisting of ammonia and alkanolamines. <30> The dye composition for regenerated collagen fibers according to any one of <1> to <29>, wherein the content of component (A) in the first agent is preferably 0.01% by mass or more and 5.0% by mass or less, more preferably 0.02% by mass or more and 3.0% by mass or less, even more preferably 0.05% by mass or more and 3.0% by mass or less, still more preferably 0.1% by mass or more and 3.0% by mass or less, still more preferably 0.2% by mass or more and 3.0% by mass or less, still more preferably 0.3% by mass or more and 3.0% by mass or less, and still more preferably 0.5% by mass or more and 2.0% by mass or less.

[0196] <31> The dye composition for regenerated collagen fibers according to any one of <1> to <30>, wherein the total content of component (A1) and component (A2) in the first agent is preferably 0.01% by mass or more and 5.0% by mass or less, more preferably 0.02% by mass or more and 3.0% by mass or less, even more preferably 0.05% by mass or more and 2.0% by mass or less, still more preferably 0.1% by mass or more and 1.5% by mass or less, still more preferably 0.2% by mass or more and 1.5% by mass or less, and even more preferably 0.25% by mass or more and 1.0% by mass or less. <32> The dye composition for regenerated collagen fibers according to any one of <1> to <31>, wherein the content of the alkaline agent in the first agent is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 7.5% by mass or less, even more preferably 0.5% by mass or more and 7.5% by mass or less, and still more preferably 1.0% by mass or more and 5.0% by mass or less. <33> The dye composition for regenerated collagen fibers according to any one of <1> to <32>, wherein the water content in the first agent is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and preferably 99.98% by mass or less. <34> The dye composition for regenerated collagen fibers according to any one of <1> to <33>, wherein the pH of the first agent is preferably 6 or more and 12.0 or less, more preferably 8 or more and 11.5 or less, even more preferably 10 or more and 11.0 or less. <35> The dye composition for regenerated collagen fibers according to any one of <1> to <34>, wherein the dosage form of the first agent is liquid, paste, cream, gel, foam, spray, or wax, and is preferably liquid. <36> The dye composition for regenerated collagen fibers according to any one of <1> to <35>, wherein the content of hydrogen peroxide in the second agent is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, and even more preferably 1.0% by mass or more and 8.0% by mass or less. <37> The dye composition for regenerated collagen fibers according to any one of <1> to <36>, wherein the pH of the second agent is preferably 2.5 or more and 6 or less, more preferably 2.5 or more and 5 or less, and even more preferably 3.0 or more and 4 or less.<38> The dye composition for regenerated collagen fibers according to any one of <1> to <37>, wherein the dosage form of the second agent is liquid, paste, cream, gel, foam, spray, or wax, and is preferably liquid. <39> The dye composition for regenerated collagen fibers according to any one of <1> to <38>, wherein the mixing ratio of the first agent to the second agent (mass ratio) is preferably in the range of 1:0.1 to 1:10, more preferably 1:0.2 to 1:5, and even more preferably 1:0.5 to 1:3. <40> The dye composition for regenerated collagen fibers according to any one of <1> to <39>, wherein the pH of the composition after mixing the first agent and the second agent is preferably 3.0 to 7.5, more preferably 3.5 to 7.0, and even more preferably 4.0 to 6.5 at 25°C.

[0197] <41> The dye composition for regenerated collagen fibers according to any one of <1> to <40>, wherein the content of component (A) or a reaction product of component (A) in the dye composition is preferably 0.005% by mass or more and 3.0% by mass or less, more preferably 0.01% by mass or more and 3.0% by mass or less, even more preferably 0.02% by mass or more and 3.0% by mass or less, still more preferably 0.03% by mass or more and 2.0% by mass or less, still more preferably 0.05% by mass or more and 2.0% by mass or less, still more preferably 0.1% by mass or more and 2.0% by mass or less, and still more preferably 0.2% by mass or more and 1.0% by mass or less. <42> The dye composition for regenerated collagen fibers according to any one of <1> to <41>, wherein the content of the alkaline agent in the dye composition is preferably 0.005% by mass or more and 5.0% by mass or less, more preferably 0.01% by mass or more and 3.5% by mass or less, even more preferably 0.1% by mass or more and 3.5% by mass or less, still more preferably 0.5% by mass or more and 3.5% by mass or less, and even more preferably 1.0% by mass or more and 2.5% by mass or less. <43> The dye composition for regenerated collagen fibers according to any one of <1> to <42>, wherein the content of water in the dye composition is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and preferably 99.9% by mass or less. <44> The dye composition for regenerated collagen fibers according to any one of <1> to <43>, wherein the component (B1) comprises one or more selected from the group consisting of benzoic acid, sodium benzoate, and potassium benzoate, preferably one or more selected from the group consisting of benzoic acid and sodium benzoate. <45> The dye composition for regenerated collagen fibers according to any one of <1> to <44>, wherein the component (B2) comprises a copolymer containing structural units derived from one or more selected from the group consisting of unsaturated monocarboxylic acids and unsaturated dicarboxylic acids, and structural units derived from an aromatic vinyl compound, preferably one or more selected from the group consisting of styrene-maleic acid copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, vinylbenzoic acid-maleic acid copolymer, vinylbenzoic acid-acrylic acid copolymer, vinylbenzoic acid-methacrylic acid copolymer, and styrene-4-vinylbenzoic acid copolymer, more preferably styrene-maleic acid copolymer.<46> The dye composition for regenerated collagen fibers according to any one of <1> to <45>, wherein in the component (B2), the ratio of the structural unit (u1) derived from the unsaturated monomer having a carboxy group to the structural unit (u2) derived from the aromatic vinyl compound monomer, in terms of molar ratio (u1 / u2), is preferably 1 / 5 to 5 / 1, more preferably 1 / 3 to 3 / 1, and even more preferably 1 / 2 to 2 / 1. <47> The dye composition for regenerated collagen fibers according to any one of <1> to <46>, wherein the acid value of the component (B2) is preferably 100 mgKOH / g or more and 1,000 mgKOH / g or less, more preferably 200 mgKOH / g or more and 800 mgKOH / g or less, even more preferably 200 mgKOH / g or more and 600 mgKOH / g or less, still more preferably 300 mgKOH / g or more and 600 mgKOH / g or less, and even more preferably 400 mgKOH / g or more and 600 mgKOH / g or less. <48> The dye composition for regenerated collagen fibers according to any one of <1> to <47>, wherein the weight-average molecular weight of the component (B2) is preferably from 3,000 to 15,000, more preferably from 5,000 to 15,000, even more preferably from 6,000 to 15,000, and still more preferably from 6,000 to 10,000. <49> The dye composition for regenerated collagen fibers according to any one of <1> to <48>, wherein the compound (B) preferably comprises one or more selected from the group consisting of benzoic acid, sodium benzoate, and a styrene-maleic acid copolymer, and more preferably comprises a styrene-maleic acid copolymer. <50> The dye composition for regenerated collagen fibers according to any one of <1> to <49>, wherein the content of compound (B) in the modified regenerated collagen fibers is preferably 0.1% by mass or more and 70% by mass or less, more preferably 0.5% by mass or more and 65% by mass or less, even more preferably 1.0% by mass or more and 60% by mass or less, still more preferably 3.0% by mass or more and 55% by mass or less, still more preferably 5.0% by mass or more and 50% by mass or less, still more preferably 10% by mass or more and 45% by mass or less, still more preferably 15% by mass or more and 40% by mass or less, and still more preferably 20% by mass or more and 40% by mass or less.

[0198] <51> The dye composition for regenerated collagen fibers according to any one of <1> to <50>, wherein the modified regenerated collagen fibers further contain, as component (C), a polyvalent metal, or a salt or complex thereof. <52> The dye composition for regenerated collagen fibers according to any one of <1> to <51>, wherein component (C) contains one or more polyvalent metals selected from the group consisting of calcium, magnesium, strontium, barium, zinc, chromium, aluminum, titanium, zirconium, tin, lead, antimony, iron, and copper, or a salt thereof, or a complex thereof, preferably one or more polyvalent metals selected from the group consisting of aluminum, zirconium, and titanium, or a salt thereof, or a complex thereof, and more preferably aluminum, or a salt thereof, or a complex thereof. <53> The dye composition for regenerated collagen fibers according to any one of <1> to <52>, wherein the content of component (C) in the modified regenerated collagen fibers is, in terms of the amount of metal elements, preferably from 0.1% by mass to 40% by mass, more preferably from 0.5% by mass to 30% by mass, even more preferably from 1.0% by mass to 20% by mass, and still more preferably from 2% by mass to 10% by mass. <54> A method for dyeing regenerated collagen fibers, wherein the regenerated collagen fibers comprise modified regenerated collagen fibers containing one or more compounds (B) selected from the group consisting of the following components (B1) and (B2): (B1) benzoic acid or a salt thereof (B2) a copolymer containing a structural unit derived from an unsaturated monomer having a carboxy group and a structural unit derived from an aromatic vinyl compound, the copolymer having an acid value of 100 mg KOH / g or more and a weight average molecular weight of 1,500 or more and 15,000 or less, or a salt thereof, and the dyeing method sequentially comprises the following steps (I) and (II):Step (I): A step of mixing at least a first agent and a second agent to prepare a dye composition for regenerated collagen fibers. Here, the first agent is an oxidation dye intermediate (A) containing one or more selected from the group consisting of the following components (A1) and (A2): (A1) One or more selected from the group consisting of a coupler (A1-1) having a benzene ring, having electron donating groups at the 1st and 3rd positions on the benzene ring, and hydrogen atoms at the 4th and 6th positions, a coupler (A1-2) having a pyridine ring, having electron donating groups at the 2nd and 6th positions on the pyridine ring, and hydrogen atoms at the 3rd and 5th positions, and a coupler (A1-3) represented by the following general formula (A13): (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26are each independently a hydrogen atom, an alkyl group, or an electron-donating group.) (A2) is one or more couplers other than the component (A1), selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions; an alkaline agent; and water; and the second agent contains hydrogen peroxide and water. <55> The dyeing method of <54>, wherein in the step (II), the method of applying the dye composition to the regenerated collagen fibers comprises a method of applying the composition to dry or wet regenerated collagen fibers, or a method of immersing the regenerated collagen fibers in the composition, and preferably a method of applying the composition to dry regenerated collagen fibers, or a method of immersing the regenerated collagen fibers in the composition. <56> The dyeing method of <54> or <55>, wherein in the step (II), the amount of the dye composition applied to the regenerated collagen fibers is preferably a liquor ratio (dry mass of regenerated collagen fibers:mass of dye composition), when the mass of the fibers after conditioning at 20°C and a relative humidity of 65% for 24 hours is taken as the dry mass. <57> The dyeing method according to <56>, wherein in the step (II), when the dye composition is applied to the regenerated collagen fibers, the amount of the dye composition applied to the regenerated collagen fibers is, when the mass of the fibers after conditioning at 20°C and a relative humidity of 65% for 24 hours is taken as the dry mass, the bath ratio (dry mass of regenerated collagen fibers:mass of dye composition), is more preferably 1:0.2 to 1:200, even more preferably 1:0.2 to 1:100, still more preferably 1:0.2 to 1:50, still more preferably 1:0.2 to 1:20, more preferably 1:0.5 to 1:10, even more preferably 1:0.5 to 1:5, and still more preferably 1:0.8 to 1:3.<58> The dyeing method according to <56>, wherein, in the step (II), when the regenerated collagen fibers are immersed in the dye composition, the bath ratio (dry mass of regenerated collagen fibers:mass of dye composition) is more preferably 1:2 to 1:500, even more preferably 1:3 to 1:250, still more preferably 1:5 to 1:100, even more preferably 1:10 to 1:50, and still more preferably 1:10 to 1:20, when the mass of the fibers after conditioning at 20°C and a relative humidity of 65% for 24 hours is taken as the dry mass. <59> The dyeing method according to any one of <55> to <58>, wherein, in the step (II), when the dye composition is applied to the regenerated collagen fibers, the application time is preferably 10 seconds to 10 minutes, more preferably 20 seconds to 5 minutes. <60> The dyeing method according to any one of <55> to <57> and <59>, wherein in the step (II), after applying the dye composition to the regenerated collagen fibers, a step of leaving the fibers to stand is further carried out, and the leaving time is preferably from 1 minute to 1 hour, more preferably from 3 minutes to 30 minutes, and even more preferably from 5 minutes to 30 minutes.

[0199] <61> The dyeing method of any one of <55>, <56>, and <58>, wherein, in the step (II), when the regenerated collagen fibers are immersed in the stain composition, the immersion time is preferably from 10 seconds to 3 hours, more preferably from 10 seconds to 2 hours, and even more preferably from 30 seconds to 1 hour. <62> The dyeing method of any one of <54> to <61>, wherein, in the step (II), the temperature when the stain composition is applied to the regenerated collagen fibers is preferably from 5°C to 40°C, and more preferably from 10°C to 35°C. <63> The dyeing method of any one of <54> to <62>, comprising a step of rinsing the stain composition applied to the regenerated collagen fibers after performing the step (II). <64> The dyeing method of any one of <54> to <63>, comprising a step of drying the regenerated collagen fibers after applying the stain composition to the regenerated collagen fibers, or after performing the rinsing step, if any. <65> Colored modified regenerated collagen fibers containing the following components (A0) and (B): (A0) a reaction product of an oxidation dye intermediate (A) containing one or more selected from the group consisting of the following components (A1) and (A2): (A1) one or more selected from the group consisting of couplers (A1-1) having a benzene ring, electron-donating groups at the 1- and 3-positions on the benzene ring, and hydrogen atoms at the 4- and 6-positions, couplers (A1-2) having a pyridine ring, electron-donating groups at the 2- and 6-positions on the pyridine ring, and hydrogen atoms at the 3- and 5-positions, and couplers (A1-3) represented by the following general formula (A13): (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26are each independently a hydrogen atom, an alkyl group, or an electron-donating group.) (A2) is one or more couplers other than the component (A1), selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions. (B) is one or more compounds selected from the group consisting of the following components (B1) and (B2): (B1) benzoic acid or a salt thereof; (B2) is a copolymer containing structural units derived from an unsaturated monomer having a carboxy group and structural units derived from an aromatic vinyl compound, and having an acid value of 100 mgKOH / g or more and a weight-average molecular weight of 1,500 to 15,000, or a salt thereof. <66> The colored and modified regenerated collagen fiber of <65>, wherein the colored and modified regenerated collagen fiber further contains the component (C): a polyvalent metal, or a salt or complex thereof. <67> A fiber for a head ornament, comprising the colored and modified regenerated collagen fiber of <65> or <66>. <68> A head ornament, comprising the colored and modified regenerated collagen fiber of <65> or <66>. <69> The fiber for a head ornament of <67> or the head ornament of <68>, wherein the head ornament is a hair wig, hairpiece, weaving, hair extension, braided hair, hair accessory, or doll hair.

[0200] <70> A dye composition for regenerated collagen fibers, comprising a mixture of at least a first agent and a second agent, wherein the first agent contains one or more oxidation dye intermediates (A) selected from meta-aminophenol, resorcinol, meta-phenylenediamine, 2-methylresorcinol, 1-naphthol, 2,6-diaminopyridine, 1,3-bis(2,4-diaminophenoxy)propane, and salts thereof, an alkaline agent, and water, the second agent contains hydrogen peroxide and water, and the regenerated collagen fibers comprise modified regenerated collagen fibers containing one or more compounds (B) selected from the group consisting of the following components (B1) and (B2): (B1) benzoic acid or a salt thereof, and (B2) a styrene-maleic acid copolymer or a salt thereof having an acid value of 200 mg KOH / g or more and 600 mg KOH / g or less and a weight-average molecular weight of 3,000 or more and 15,000 or less.

[0201] <71> A method for dyeing regenerated collagen fibers, the method comprising the following steps (I) and (II) in this order, wherein the regenerated collagen fibers comprise modified regenerated collagen fibers containing one or more compounds (B) selected from the group consisting of the following components (B1) and (B2): Step (I): Mixing at least a first agent and a second agent to prepare a dye composition for regenerated collagen fibers, wherein the first agent contains one or more oxidation dye intermediates (A) selected from meta-aminophenol, resorcinol, meta-phenylenediamine, 2-methylresorcinol, 1-naphthol, 2,6-diaminopyridine, 1,3-bis(2,4-diaminophenoxy)propane, and salts thereof, an alkali agent, and water, and the second agent contains hydrogen peroxide and water. Step (II): A step of applying the regenerated collagen fiber dye composition to the regenerated collagen fiber. (B1) Benzoic acid or a salt thereof. (B2) A styrene-maleic acid copolymer or a salt thereof having an acid value of 200 mg KOH / g or more and 600 mg KOH / g or less and a weight average molecular weight of 3,000 or more and 15,000 or less.

[0202] <72> A colored modified regenerated collagen fiber containing the following component (A0) and component (B), wherein the colored modified regenerated collagen fiber is obtained by dyeing a modified regenerated collagen fiber containing component (B) using a dye composition prepared by mixing at least a first agent containing an oxidative dye intermediate (A), an alkaline agent, and water, and a second agent containing hydrogen peroxide and water. (A0) a reaction product of one or more oxidation dye intermediates (A) selected from meta-aminophenol, resorcinol, meta-phenylenediamine, 2-methylresorcinol, 1-naphthol, 2,6-diaminopyridine, 1,3-bis(2,4-diaminophenoxy)propane, and salts thereof; (B) one or more compounds selected from the group consisting of the following components (B1) and (B2): (B1) benzoic acid or a salt thereof; (B2) a styrene-maleic acid copolymer or a salt thereof having an acid value of 200 mgKOH / g or more and 600 mgKOH / g or less and a weight average molecular weight of 3,000 or more and 15,000 or less;

[0203] <73> The dye composition of <70>, the dyeing method of <71>, or the colored modified regenerated collagen fiber of <72>, wherein the modified regenerated collagen fiber contains, as component (B2), a styrene-maleic acid copolymer or a salt thereof having an acid value of 200 mgKOH / g or more and 600 mgKOH / g or less and a weight-average molecular weight of 6,000 or more and 15,000 or less. <74> The dye composition of <70> or <73>, the dyeing method of <71> or <73>, or the colored modified regenerated collagen fiber of <72> or <73>, wherein the modified regenerated collagen fiber contains, as component (B2), a styrene-maleic acid copolymer or a salt thereof having an acid value of 400 mgKOH / g or more and 600 mgKOH / g or less and a weight-average molecular weight of 6,000 or more and 10,000 or less.

[0204] <75> The dye composition of any one of <70> and <73> to <74>, or the dyeing method of any one of <71> and <73> to <74>, wherein the mass ratio of the total content of component (A1) and component (A2) of the oxidation dye intermediate (A) in the first agent to the hydrogen peroxide in the second agent, [[(A1) + (A2)] / hydrogen peroxide], is from 0.03 to 1.0. <76> The dye composition of any one of <70> and <73> to <75>, the dyeing method of any one of <71> and <73> to <75>, or the colored modified regenerated collagen fiber of any one of <72> to <75>, wherein the content of compound (B) in the modified regenerated collagen fiber is from 20% by mass to 40% by mass. <77> The dye composition of any one of <70> and <73> to <76>, the dyeing method of any one of <71> and <73> to <76>, or the colored modified regenerated collagen fiber of any one of <72> to <76>, wherein the mass ratio [(B) / (A)] of the compound (B) in the fiber for head accessories to the oxidation dye intermediate (A) in the dye composition is 20 or more and 100 or less.

[0205] <78> The dye composition of any one of <70> and <73> to <77>, or the dyeing method of any one of <71> and <73> to <77>, or the colored modified regenerated collagen fiber of any one of <72> to <77>, wherein the modified regenerated collagen fiber contains aluminum or a salt or complex thereof as component (C). <79> The dye composition of <78>, the dyeing method of <78>, or the colored modified regenerated collagen fiber of <78>, wherein the content of component (C) in the modified regenerated collagen fiber is 2.0% by mass or more and 10% by mass or less, in terms of the amount of metal element. <80> The dye composition of <78> or <79>, the dyeing method of <78> or <79>, or the colored modified regenerated collagen fiber of <78> or <79>, wherein the mass ratio [(C) / (A)] of the component (C) in the fiber for head accessories to the oxidation dye intermediate (A) in the dye composition is 2 or more and 20 or less.

[0206] <81> A head accessory product comprising the colored modified regenerated collagen fiber according to any one of <72> to <80>.

[0207] The present invention will be described below with reference to examples, but the present invention is not limited to the scope of the examples. In the examples, various measurements and evaluations were carried out by the following methods.

[0208] <pH Measurement> The pH at 25° C. was measured using a pH meter (F-72, manufactured by Horiba Ltd.).

[0209] Quantification of Benzoic Acid in Modified Regenerated Collagen Fibers In this specification, the quantification of benzoic acid contained in the modified regenerated collagen fiber B1 obtained in Production Example 2 was carried out using the following method. Reagents: 6N hydrochloric acid: titrant for volumetric analysis, manufactured by Kanto Chemical Co., Ltd. Sodium acetate: special grade, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. Acetic acid: special grade, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. Acetonitrile: for LC / MS, manufactured by Kanto Chemical Co., Ltd. Sodium benzoate: special grade, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. Ultrapure water: water produced by ultrapure water production system Milli-Q, manufactured by Millipore Corporation Quantification Method: The sample (modified regenerated collagen fiber B1) was conditioned at 20°C and a relative humidity of 65% for 24 hours, then finely chopped. Approximately 10 mg of the sample was precisely weighed, and 3 mL of 6N hydrochloric acid was added. The mixture was then heated and dissolved at 50°C for 15 hours. After cooling, the solution was filtered to obtain a sample solution. Separately, sodium benzoate was dissolved in the mobile phase to prepare a standard solution with a benzoic acid concentration of 0.1 to 100 μg / mL. This was used to construct a calibration curve. Liquid chromatography (HPLC) measurements were performed using the sample solution and the standard solution, and the amount of benzoic acid was calculated from the ratio of the peak area of ​​the sample solution to that of the standard solution. Measurement conditions: Detector: UV-Visible Spectrophotometer; Measurement Wavelength: 230 nm; Column: A stainless steel tube with an inner diameter of 21 mm and a length of 150 mm was packed with 5 μm octadecylsilylated silica gel for liquid chromatography. Column temperature: A constant temperature of approximately 40°C. Mobile phase: Approximately 0.68 g of sodium acetate and 0.91 g of acetic acid were dissolved in 750 mL of ultrapure water, followed by the addition of 250 mL of acetonitrile and mixing. HPLC / UV conditions: Apparatus: UltiMate 3000 system (Thermo Fisher Scientific) Column: L column 2 ODS 5 μm 2.1 × 150 mm (Chemicals Evaluation and Research Institute, Japan) Column temperature: 40°C Mobile phase: 20 mM ammonium acetate 25% acetonitrile buffer Analysis time: 10 minutes Detector: DAD (diode array detector) Detection wavelength: 230 nm Flow rate: 0.3 mL / min (isocratic elution) Injection volume: 10 μL

[0210] <Weight-Average Molecular Weight of Styrene-Maleic Acid Copolymer> In this specification, the weight-average molecular weight of the styrene-maleic acid copolymer was measured under the following conditions, and the weight-average molecular weight in terms of polystyrene was determined. (1) Reagents: Ultrapure water: water produced by an ultrapure water production system, Milli-Q, manufactured by Millipore Corporation; Dimethylformamide (DMF): special grade, manufactured by Kanto Chemical Co., Ltd.; Lithium bromide monohydrate (LiBr): special grade, manufactured by Kanto Chemical Co., Ltd.; Phosphoric acid: special grade, manufactured by Sigma-Aldrich Co., Ltd. (2) Sample Pretreatment Method: Approximately 50 mg of sample was precisely weighed, 0.5 mL of ultrapure water was added, and 10 mL of the mobile phase described below was added to dissolve the solution, which was then filtered to obtain a sample solution. (3) Measurement: Using the sample solution and standard solution, gel permeation chromatography (GPC) was performed under the following conditions to determine the weight-average molecular weight in terms of polystyrene. Flow rate: 1 mL / min Mobile phase: DMF containing 60 mM phosphoric acid and 50 mM LiBr Column: TSKgel α (alpha) column (manufactured by Tosoh Corporation) Detector: RI (differential refractive index detector)

[0211] <Quantitative Determination of Styrene-Maleic Acid Copolymer in Modified Regenerated Collagen Fiber> In this specification, the quantitative determination of the styrene-maleic acid copolymer in the modified regenerated collagen fiber B2 obtained in Production Example 3 was carried out by the following method. (1) Reagents: 1 mol / L aqueous sodium hydroxide solution: for volumetric analysis, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Ultrapure water: water produced by an ultrapure water production system, Milli-Q, manufactured by Millipore Corporation Dimethylformamide (DMF): special grade, manufactured by Kanto Chemical Co., Inc. Lithium bromide monohydrate (LiBr): special grade, manufactured by Kanto Chemical Co., Inc. Phosphoric acid: special grade, manufactured by Sigma-Aldrich (2) Sample Solution: The sample (modified regenerated collagen fiber B2) was conditioned at 20°C and a relative humidity of 65% for 24 hours, then finely chopped, and approximately 50 mg was precisely weighed out. 10 mL of 1 mol / L aqueous sodium hydroxide solution was added and the mixture was dissolved by heating at 50°C for 3 hours. The pH of the solution was adjusted to 4.7-5.3, and the freeze-dried sample was diluted with 0.5 mL of ultrapure water and 9.5 mL of the mobile phase described below. The diluted solution was filtered to prepare the sample solution. (3) Preparation of calibration curve solution: Separately, styrene-maleic acid copolymer was dissolved in the mobile phase described below to prepare a non-dissociated styrene-maleic acid copolymer with a concentration of 0.25-5.0 mg / mL, which was used as the standard solution for drawing the calibration curve. (4) Measurement: Using the sample solution and the standard solution, gel permeation chromatography (GPC) measurements were performed under the following conditions, and the peak areas of the sample solution and the standard solution were determined. A calibration curve was also prepared based on the peak area results of the standard solution. Flow rate: 0.8 mL / min Mobile phase: DMF containing 60 mM phosphoric acid and 50 mM LiBr Column: TSKgel α (Alpha) column (manufactured by Tosoh Corporation) Detector: UV-visible spectrophotometer Measurement wavelength: 267 nm (5) Calculation of the amount of styrene-maleic acid copolymer The amount of styrene-maleic acid copolymer per mass of fiber was calculated using a calibration curve created based on the peak area derived from the styrene-maleic acid copolymer contained in the modified regenerated collagen fibers.

[0212] <Quantification of Aluminum in Modified Regenerated Collagen Fibers> In this specification, the quantification of aluminum in modified regenerated collagen fibers was performed using the following method. (1) Reagents: Sulfuric acid: precision analysis grade, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. Hydrochloric acid: metal analysis grade, manufactured by Kanto Chemical Co., Ltd. Sodium carbonate: special grade, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. Boric acid: special grade, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. Aluminum standard solution: 1000 mg / L for atomic absorption spectrometry, manufactured by Kanto Chemical Co., Ltd. Ultrapure water: water produced by ultrapure water production system Milli-Q, manufactured by Millipore Corporation. (2) Sample Pretreatment Method: A fiber bundle of modified regenerated collagen fibers was hung in a dryer (SOFW-450SB, AS ONE Corporation) set to 60°C, a 250 g weight was attached to the bottom end of the fiber bundle, and the fiber was dried for 1 hour with tension applied to the entire fiber. The fiber was then removed from the dryer and conditioned at 20°C and 65% relative humidity for 24 hours. 0.1 g of sample (modified regenerated collagen fiber) was precisely weighed into a platinum crucible and heated until no white smoke was produced. Several drops of sulfuric acid were added, and the mixture was heated again until no white smoke was produced. It was then thoroughly incinerated in a 550°C electric furnace. 1 g of alkaline flux (sodium carbonate:boric acid = 1:0.4) was then added and melted in a 950°C electric furnace. A watch glass was placed over the sample, and 5 mL of ultrapure water and hydrochloric acid (6 mol / L) were added. The mixture was heated and dissolved on a hot plate at 70-80°C. After cooling, the solution was adjusted to a constant volume of 50 mL with ultrapure water. This solution was used as the measurement solution. (3) Preparation of Calibration Solutions: Calibration solutions ranging from 0.1 to 20 mg / L were prepared using an aluminum standard solution (1000 mg / L). Alkaline flux and hydrochloric acid were added to each solution to achieve the same concentration as the measurement solution. (4) Measurement: Using the prepared measurement solutions, each element was measured using an ICP atomic emission spectrometer under the following conditions. Analysis device: iCAP6500Duo (manufactured by Thermo Fisher Scientific) Wavelength: Al 396.152 nm RF power: 1150 W Coolant gas flow rate: 12 L / min Nebulizer flow rate: 0.70 L / min Auxiliary gas: 0.5 L / min Pump flow rate: 50 rpm

[0213] Production Example 1 (Production of Regenerated Collagen Fiber C0) Cattle split hide was solubilized with alkali according to a conventional method to prepare a spinning dope, which was then discharged from a spinning nozzle into a coagulation bath to produce regenerated collagen fibers. The regenerated collagen fibers were immersed in 30 parts by weight of an aqueous solution containing 5.0% by weight of aluminum sulfate 14-18 hydrate, 0.65% by weight of citric acid monohydrate, and 1.3% by weight of sodium hydroxide (component (C))) at 30°C with circulation, with the dry mass of the fiber measured after conditioning at 20°C and 65% relative humidity for 24 hours. A 5% aqueous solution of sodium hydroxide was then added in portions over approximately 1 to 5 hours to adjust the final pH of the solution to 4.5 to 5.0 after 5 hours. The regenerated collagen fibers were then retained in the solution for 3 hours and thoroughly washed with water to obtain regenerated collagen fiber C0.

[0214] Production Example 2 (Production of Modified Regenerated Collagen Fiber B1) The regenerated collagen fiber C0 obtained in Production Example 1 was treated according to the following procedure to obtain modified regenerated collagen fiber B1. (Procedure 1) Ten 30 cm fiber bundles (amount that would weigh 1.5 g when dried at 60°C for 1 hour and then left at 20°C and 65% RH for 12 hours) were prepared from the regenerated collagen fiber C0 for each Example and Comparative Example. (Procedure 2) Benzoic acid (Wako Special Grade Reagent, Fujifilm Wako Pure Chemical Industries, Ltd., molecular weight: 122), component (B1), was dissolved in water, and the pH was adjusted to 6.0 with a pH adjuster (sodium hydroxide) to prepare a fiber treatment agent containing 25.4 mass% benzoic acid. The fiber bundles were immersed in a separate container in an amount of fiber treatment agent such that the bath ratio (mass of fiber bundle after drying in Step 1: mass of fiber treatment agent) was 1:30, and the opening of each container was sealed. (Procedure 3) The entire container was immersed in a water bath (TBS221FA, Toyo Seisakusho Co., Ltd.) set to 40°C and left to stand for 5 minutes. The liquid temperature in the container was raised to 40°C, and then the container was removed from the water bath. (Procedure 4) The container containing the fiber bundle was placed on a stirring rotor (VMR-5R, AS ONE Corporation) installed in a dryer (SOFW-450SB, AS ONE Corporation) set to 40°C, and the container was rotated at a rotation speed of 80 rpm and heated and stirred for 3 hours. (Procedure 5) The container containing the fiber bundle was removed from the dryer and allowed to return to room temperature. The fiber bundle was then removed from the container and rinsed with running tap water at 30°C for 30 seconds, and the flow of the fibers was adjusted with a comb. (Step 6) The fiber bundles were hung one by one in a dryer set at 60°C, and a 250g weight was attached to the bottom end of each fiber bundle, and dried for 1 hour with tension applied to the entire fiber. (Step 7) The fiber bundles were removed from the dryer, returned to room temperature, and the weight was removed.

[0215] The content of benzoic acid in the modified regenerated collagen fiber B1 produced in Production Example 2 above was 27.3% by mass calculated as benzoic acid, and the content of aluminum was 5.7% by mass.

[0216] Production Example 3 (Production of Modified Regenerated Collagen Fiber B2) The regenerated collagen fiber C0 obtained in Production Example 1 was treated according to the following procedure to obtain modified regenerated collagen fiber B2. (Procedure 1) Ten 30 cm long fiber bundles (amount sufficient to yield a mass of 1.5 g when dried at 60°C for 1 hour and then left at 20°C and 65% RH for 12 hours) were prepared from the regenerated collagen fiber C0 for each Example. First, the following (Procedure 2) to (Procedure 5) were carried out using the B2a agent shown in Table 1. Agents B2a and B2b shown in Table 1 were prepared by blending and mixing the respective components listed in Table 1 using styrene-maleic acid copolymer (XIRAN1000HNa, manufactured by Polyscope, weight average molecular weight (Mw): 9195, acid value: 475 mg KOH / g, styrene / maleic acid molar ratio: 1 / 1) as component (B2). (Procedure 2) The fiber bundles prepared in (Procedure 1) were immersed in a container, one bundle at a time, in an amount of B2a agent such that the bath ratio (mass of fiber bundle after drying in Procedure 1: mass of B2a agent) was 1:30, and the opening of each container was sealed. (Procedure 3) The container was immersed in a water bath (TBS221FA, Toyo Seisakusho Co., Ltd.) set at 40°C and left to stand for 5 minutes. The liquid temperature in the container was then raised to 40°C, and the container was then removed from the water bath. (Procedure 4) The container containing the fiber bundle was placed on a stirring rotor (VMR-5R, AS ONE Corporation) installed in a dryer (SOFW-450SB, AS ONE Corporation) set at 40°C, and the container was rotated at a rotation speed of 80 rpm, and heated and stirred for 6 hours. (Procedure 5) The container containing the fiber bundle was removed from the dryer and allowed to return to room temperature. The fiber bundle was then removed from the container, rinsed with running tap water at 30°C for 30 seconds, and the fiber flow was adjusted with a comb. (Procedure 6) The fiber bundle obtained in (Procedure 5) was subjected to (Procedure 2) to (Procedure 5) again, using the B2b agent shown in Table 1 instead of the B2a agent. However, the heating and stirring time in (Procedure 4) was set to 1 hour. (Procedure 7) The fiber bundles obtained in (Procedure 6) were hung one by one in a dryer set to 60°C, and a 250g weight was attached to the bottom end of each fiber bundle. They were dried for 1 hour with tension applied to the entire fiber. (Procedure 8) The fiber bundle was removed from the dryer, allowed to return to room temperature, and the weight was removed.

[0217]

[0218] The blending amounts (% by mass) listed in Table 1 are all amounts of active ingredients. The styrene-maleic acid copolymer content in the modified regenerated collagen fiber B2 produced in Production Example 3 above was 31.4% by mass, and the aluminum content was 5.5% by mass.

[0219] Examples 1 to 3, Comparative Example 1 (Preparation of dye composition for regenerated collagen fibers) The components shown in "First agent" in Table 2 were blended in the blending ratios shown in Table 2 and mixed until uniform to prepare a first agent. Similarly, the components shown in "Second agent" in Table 2 were blended in the blending ratios shown in Table 2 and mixed until uniform to prepare a second agent. Next, the first agent and the second agent were mixed in the mass ratios shown in Table 2 to prepare a dye composition for regenerated collagen fibers.

[0220] Examples 4 to 8 and Comparative Examples 2 to 5 (Evaluation of dye compositions for regenerated collagen fibers) The dye compositions obtained by the above methods were used to evaluate dyeability and fastness according to the following methods. The results are shown in Table 2.

[0221] <Dyeability (color difference before and after dyeing ΔE * ab)> A fiber bundle having a length of 10 cm and a mass of 1 g was prepared using the modified regenerated collagen fibers shown in Table 2. The fiber bundle was washed with plain shampoo having the following composition, then rinsed with warm water at 40°C, and thoroughly dried with a dryer. The hue (L0) of the fiber bundle (before dyeing) was * , a0 * , b0 * ) was measured using a color difference meter (CR-400, Konica Minolta, Inc.). * , a0 * , b0 *For each, measurements were taken at six points per fiber bundle to determine the average value. Next, 2 g of a dye composition prepared by mixing the first and second agents shown in Table 2 in the ratios shown in Table 2 was applied to the fiber bundle, and the fiber bundle was placed in a glass Petri dish, the opening of which was covered with aluminum foil, and the fiber bundle was left floating in a water bath (TBS221FA, Toyo Seisakusho Co., Ltd.) set to 30°C for 30 minutes. After leaving the fiber bundle for 30 minutes, the fiber bundle was rinsed with warm water at 40°C for 30 seconds to wash away the dye composition, and the fiber bundle was lathered with a plain shampoo having the following composition for 15 seconds and then rinsed with warm water at 40°C for 15 seconds, this operation being repeated twice. Next, a plain conditioner having the following composition was applied for 15 seconds, followed by rinsing with warm water at 40°C for 15 seconds, and the fiber bundle was thoroughly dried with cold air from a dryer. The dried fiber bundle (dyed fiber bundle) was measured for hue (L1) using a colorimeter in the same manner as above. * , a1 * , b1 * The color difference ΔE before and after dyeing of the fiber bundle was calculated using the following formula: * ab1 was calculated and shown in Table 2. ΔE * A larger ab1 value means higher staining ability.

[0222] ΔE * ab1 = [(L1 * -L0 * ) 2 + (a1 * -a0 * ) 2 + (b1 * -b0 * ) 2 〕 1 / 2

[0223] (Composition of plain shampoo) Ingredients (mass%) Polyoxyethylene (2) sodium lauryl ether sulfate (*1) 15.5 Lauric acid diethanolamide (*2) 1.5 Edetic acid tetrasodium salt 0.3 Sodium benzoate 1.43 Purified water Remaining amount Total 100.0 *1: Emar 227 (manufactured by Kao Corporation, 57.4 mass% as active ingredient 27 mass%) *2: Aminone L-02 (manufactured by Kao Corporation)

[0224] (Composition of plain conditioner) Ingredients (mass %) Trimethylstearylammonium chloride (*1) 1.01 Distearyldimethylammonium chloride (*2) 2.0 Propylene glycol 5.0 Cetanol (*3) 2.0 Isopropyl alcohol 0.4 Methyl parahydroxybenzoate (*4) 0.1 Purified water Remaining amount Total 100.0 *1: 3.6 mass% of Coatamine 86W (manufactured by Kao Corporation, active ingredient 28% by mass) *2: 2.7 mass% of Coatamine D86P (manufactured by Kao Corporation, active ingredient 75% by mass) *3: Kalcol 6870 (manufactured by Kao Corporation) *4: Mekkinsu M (manufactured by Ueno Pharmaceutical Co., Ltd.)

[0225] <Fastness (resistance to color fading after washing)> The dyed fiber bundle obtained in the above evaluation of "dyeability" was used as the "fiber bundle before washing." The fiber bundle before washing was immersed in a container containing 15 g of a solution prepared by diluting the plain shampoo 10 times with purified water, and the container containing the fiber bundle was placed on a stirring rotor (VMR-5R, AS ONE Corporation) installed in a dryer (SOFW-450SB, AS ONE Corporation) set to 40°C, and the container was rotated at a rotation speed of 80 rpm, and heated and stirred for 90 minutes. The container containing the fiber bundle was removed from the dryer and returned to room temperature, after which the fiber bundle was removed from the container, rinsed with running water (tap water) at 40°C for 30 seconds, and thoroughly dried with cold air from a dryer. The hue (L2 * , a2 * , b2 * The color difference ΔE before and after washing of the fiber bundle was calculated using the following formula: * ab2 was calculated and shown in Table 2. ΔE * The smaller the value of ab2, the smaller the color change due to washing.

[0226] ΔE * ab2 = [(L1 * -L2 * ) 2 + (a1 * -a2 * ) 2 + (b1 * -b2 * ) 2 〕 1 / 2

[0227] Dyeability ΔE before washing * When ab1 is small, the color difference ΔE * It was found that the measured value of ab2 was small. Therefore, in the present invention, in order to evaluate robustness more accurately, the robustness is evaluated using D obtained by the following formula as an index. The smaller the value of D, the higher the robustness.

[0228] D = (ΔE * ab2 / ΔE * ab1) x 100

[0229] The blending amounts (mass %) shown in Table 2 are all amounts of active ingredients.

[0230]

[0231] Table 2 shows that the dye composition of the present invention has better fastness to specific modified regenerated collagen fibers than the dye composition of Comparative Example 1, which uses an oxidative dye intermediate that does not contain either component (A1) or (A2).

[0232] The effects of the present invention can also be achieved using the modified regenerated collagen fiber shown in Formulation Example 1. Formulation Example 1: XIRAN3000HNa (weight average molecular weight (Mw): 13,803, acid value: 285 mg KOH / g, styrene / maleic acid molar ratio: 3 / 1, manufactured by Polyscope) is used instead of XIRAN1000HNa (manufactured by Polyscope), and the regenerated collagen fiber C0 obtained in Production Example 1 is treated in the same manner as in Production Example 3 to obtain modified regenerated collagen fiber X3. Next, the modified regenerated collagen fiber X3 is treated in the same manner as shown under (fiber treatment) using the treating agent composition shown in Table 1.

[0233] The effects of the present invention can also be achieved by using the dye compositions shown in Formulation Examples 2 and 3.

[0234]

[0235] According to the present invention, a dye composition for regenerated collagen fibers, which uses a dye and has excellent fastness for specific modified regenerated collagen fibers, can be provided.

Claims

1. A dye composition for regenerated collagen fibers, which uses a mixture of at least a first agent and a second agent, wherein the first agent contains an oxidation dye intermediate (A) containing one or more compounds selected from the group consisting of the following components (A1) and (A2), an alkaline agent, and water, the second agent contains hydrogen peroxide and water, and the regenerated collagen fibers comprise modified regenerated collagen fibers containing one or more compounds (B) selected from the group consisting of the following components (B1) and (B2): (A1) One or more couplers selected from the group consisting of a coupler (A1-1) having a benzene ring and having electron-donating groups at the 1- and 3-positions on the benzene ring and hydrogen atoms at the 4- and 6-positions, a coupler (A1-2) having a pyridine ring and having electron-donating groups at the 2- and 6-positions on the pyridine ring and hydrogen atoms at the 3- and 5-positions, and a coupler (A1-3) represented by the following general formula (A13): (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group, or an electron-donating group.) (A2) is a coupler other than the component (A1), and is one or more selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions; (B1) benzoic acid or a salt thereof; (B2) a copolymer containing structural units derived from an unsaturated monomer having a carboxy group and structural units derived from an aromatic vinyl compound, having an acid value of 100 mgKOH / g or more and a weight-average molecular weight of 1,500 to 15,000, or a salt thereof.

2. The dye composition for regenerated collagen fibers according to claim 1, wherein the oxidation dye intermediate (A) contains the component (A1).

3. The dye composition for regenerated collagen fibers according to claim 1 or 2, wherein component (A1) comprises one or more members selected from the group consisting of meta-aminophenol, resorcinol, meta-phenylenediamine, 2-methylresorcinol, 1-naphthol, 2,6-diaminopyridine, and 1,3-bis(2,4-diaminophenoxy)propane.

4. A dye composition for regenerated collagen fibers according to any one of claims 1 to 3, wherein component (A1) comprises one or more members selected from the group consisting of meta-aminophenol, resorcinol, 2-methylresorcinol, and 1-naphthol.

5. The regenerated collagen fiber dye composition according to any one of claims 1 to 4, wherein the oxidation dye intermediate (A) further contains a precursor as component (A3), and the precursor contains one or more members selected from the group consisting of toluene-2,5-diamine, para-aminophenol, 4-amino-metacresol, 1-hydroxyethyl-4,5-diaminopyrazole, and salts thereof.

6. A dye composition for regenerated collagen fibers according to any one of claims 1 to 5, wherein component (B2) comprises a styrene-maleic acid copolymer.

7. A method for dyeing regenerated collagen fibers, comprising the following steps (I) and (II) in that order, wherein the regenerated collagen fibers comprise modified regenerated collagen fibers containing one or more compounds (B) selected from the group consisting of the following components (B1) and (B2): Step (I): Mixing at least a first agent and a second agent to prepare a dye composition for regenerated collagen fibers, wherein the first agent contains an oxidation dye intermediate (A) containing one or more compounds selected from the group consisting of the following components (A1) and (A2), an alkaline agent, and water, and the second agent contains hydrogen peroxide and water. Step (II): A step of applying the regenerated collagen fiber dye composition to the regenerated collagen fibers. (A1) One or more couplers selected from the group consisting of couplers (A1-1) having a benzene ring, electron donating groups at the 1st and 3rd positions on the benzene ring, and hydrogen atoms at the 4th and 6th positions; couplers (A1-2) having a pyridine ring, electron donating groups at the 2nd and 6th positions on the pyridine ring, and hydrogen atoms at the 3rd and 5th positions; and couplers (A1-3) represented by the following general formula (A13): (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group, or an electron-donating group.) (A2) is a coupler other than the component (A1), and is one or more selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions; (B1) benzoic acid or a salt thereof; (B2) a copolymer containing structural units derived from an unsaturated monomer having a carboxy group and structural units derived from an aromatic vinyl compound, having an acid value of 100 mgKOH / g or more and a weight-average molecular weight of 1,500 to 15,000, or a salt thereof.

8. Colored modified regenerated collagen fibers containing the following components (A0) and (B): (A0) a reaction product of an oxidation dye intermediate (A) containing one or more selected from the group consisting of the following components (A1) and (A2): (A1) one or more selected from the group consisting of couplers (A1-1) having a benzene ring, electron-donating groups at the 1st and 3rd positions on the benzene ring, and hydrogen atoms at the 4th and 6th positions, couplers (A1-2) having a pyridine ring, electron-donating groups at the 2nd and 6th positions on the pyridine ring, and hydrogen atoms at the 3rd and 5th positions, and couplers (A1-3) represented by the following general formula (A13): (In formula (A13), R 11 is -O-(CH2) n R is a divalent group represented by —O— (n is a number of 2 or more and 10 or less). 12 , R 14 , R 22 and R 24 is an electron donating group, R 15 and R 25 is a hydrogen atom. 13 , R 16 , R 23 and R 26 are each independently a hydrogen atom, an alkyl group, or an electron-donating group.) (A2) is one or more couplers other than the component (A1), selected from the group consisting of couplers (A2-1) having a benzene ring, electron-donating groups at the 1- and 2-positions on the benzene ring, and hydrogen atoms at two or more of the 3- to 6-positions, and couplers (A2-2) having a pyridine ring, electron-donating groups at the 2- and 3-positions on the pyridine ring, and hydrogen atoms at two or more of the 4- to 6-positions. (B) is one or more compounds selected from the group consisting of the following components (B1) and (B2): (B1) benzoic acid or a salt thereof; (B2) is a copolymer containing structural units derived from an unsaturated monomer having a carboxy group and structural units derived from an aromatic vinyl compound, the copolymer having an acid value of 100 mgKOH / g or more and a weight-average molecular weight of 1,500 to 15,000, or a salt thereof.

9. A headwear product comprising the colored modified regenerated collagen fiber according to claim 8.

Images