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JP-2026075191-A - First agent for oxidative hair dye, oxidative hair dye, oxidative hair dye kit, and hair dyeing method

JP2026075191AJP 2026075191 AJP2026075191 AJP 2026075191AJP-2026075191-A

Abstract

[Problem] The objective is to provide a first agent for oxidative hair dye, an oxidative hair dye, an oxidative hair dye kit, and a hair dyeing method that can dye hair to a shade containing a blue tint and have excellent wash-fastness. [Solution] A first agent for oxidative hair dye, comprising (A) 2,2'-[(4-aminophenyl)imino]bisethanol or a salt thereof, (B) α-naphthol, and (C) carbonate, wherein the ratio of the molar concentration of α-naphthol to the molar concentration of 2,2'-[(4-aminophenyl)imino]bisethanol is less than 3, and 2,4-diaminophenoxyethanol or a salt thereof is either included or not included at a predetermined molar concentration. An oxidative hair dye obtained by mixing the first agent for oxidative hair dye with a second agent for oxidative hair dye containing an oxidizing agent, and a hair dyeing method using the oxidative hair dye. An oxidative hair dye kit for obtaining the oxidative hair dye. [Selection Diagram] None

Inventors

  • 山口 紗緒里

Assignees

  • 株式会社ミルボン

Dates

Publication Date
20260508
Application Date
20241022

Claims (8)

  1. (A) 2,2'-[(4-aminophenyl)imino]bisethanol or a salt thereof, (B) α-naphthol, and (C) Contains carbonate, The ratio of the molar concentration of α-naphthol to the molar concentration of 2,2'-[(4-aminophenyl)imino]bisethanol is less than 3. (D) A first agent for oxidative hair dye, which contains 2,4-diaminophenoxyethanol or a salt thereof, wherein the ratio of the molar concentration of 2,4-diaminophenoxyethanol to the molar concentration of the coupler is less than 0.03, or which does not contain (D) 2,4-diaminophenoxyethanol or a salt thereof.
  2. The first agent for oxidative hair dye according to claim 1, wherein the ratio of the molar concentration of α-naphthol to the molar concentration of 2,2'-[(4-aminophenyl)imino]bisethanol is greater than 0.51 and less than 3.
  3. The first agent for oxidative hair dye according to claim 1 or claim 2, wherein the ratio of the molar concentration of 2,4-diaminophenoxyethanol to the molar concentration of the coupler is 0.01 or less.
  4. (E) The first agent for oxidative hair dye according to claim 1 or claim 2, comprising toluene-2,5-diamine or a salt thereof.
  5. The first agent for oxidative hair dye according to claim 1 or claim 2, wherein the ratio of the molar concentration of the dye intermediate to the molar concentration of the coupler is 0.5 or more.
  6. An oxidative hair dye comprising a mixture of a first oxidative hair dye agent according to claim 1 or claim 2 and a second oxidative hair dye agent containing an oxidizing agent.
  7. An oxidative hair dye kit comprising a first agent for oxidative hair dye according to claim 1 or claim 2, and a second agent for oxidative hair dye containing an oxidizing agent.
  8. A hair dyeing method using an oxidative hair dye comprising a mixture of a first oxidative hair dye agent according to claim 1 or claim 2 and a second oxidative hair dye agent containing an oxidizing agent.

Description

This invention relates to a first agent for oxidative hair dye, an oxidative hair dye, an oxidative hair dye kit, and a hair dyeing method. Oxidative hair dyes, used for coloring hair, work on the principle of dyeing by oxidative polymerization of oxidative dyes that penetrate the hair shaft. Compared to other hair coloring agents such as acidic hair dyes, oxidative hair dyes can achieve longer-lasting color retention. As an example of an oxidative hair dye, Patent Document 1 discloses a first oxidative hair dye containing (A) toluene-2,5-diamine, (B) 2,4-diaminophenoxyethanol, (C) (C1) dialkyl phosphate, and one or more selected from polyoxyethylene alkyl ether phosphate, (C2) di-long-chain alkyldimethylammonium salt, and (C3) mono-long-chain alkyltrimethylammonium salt, wherein the ratio of the content of (A) to the content of (B) [(A)/(B)] is 0.25 or higher. It has been shown that an oxidative hair dye using the first oxidative hair dye of Patent Document 1 can enhance the intensity of blue dyeing in hair. Japanese Patent Publication No. 2018-070515 The present invention will be described below based on an embodiment of the present invention (hereinafter referred to as "this embodiment"). <First agent for oxidative hair dye> The first agent for oxidative hair dye of this embodiment (hereinafter referred to as "the first agent of this embodiment") contains (A) 2,2'-[(4-aminophenyl)imino]bisethanol or a salt thereof, (B) α-naphthol, and (C) carbonate, wherein the ratio of the molar concentration of α-naphthol to the molar concentration of 2,2'-[(4-aminophenyl)imino]bisethanol is less than 3, or (D) 2,4-diaminophenoxyethanol or a salt thereof is contained, wherein the ratio of the molar concentration of 2,4-diaminophenoxyethanol to the molar concentration of the coupler is less than 0.03, or (D) 2,4-diaminophenoxyethanol or a salt thereof is not contained. The first agent of this embodiment is essentially formulated with (A) 2,2'-[(4-aminophenyl)imino]bisethanol or its salt and (B) α-naphthol as oxidation dyes, thereby achieving a color tone that includes a blue tint. Furthermore, the first agent of this embodiment exhibits excellent hair wash fastness because it contains (C) carbonate, the ratio of the molar concentration of α-naphthol to the molar concentration of 2,2'-[(4-aminophenyl)imino]bisethanol is less than 3, and (D) 2,4-diaminophenoxyethanol or its salt is included, with the ratio of the molar concentration of 2,4-diaminophenoxyethanol to the molar concentration of the coupler being less than 0.03, or (D) 2,4-diaminophenoxyethanol or its salt is not included. In this specification, "dyeing hair to a shade containing a blue tint" refers to the process by which hair (for example, a bundle of yellow human hair, approximately 1g, approximately 10cm long, using Beaulux's "BR-3A") is dyed with an oxidative hair dye to a shade that visually contains a blue tint (for example, blue or purple). Furthermore, "wash-fastness" refers to the persistence of the dyeing effect on hair after it has been dyed with an oxidative hair dye, even after washing. In the following description, "2,2'-[(4-aminophenyl)imino]bisethanol or its salt" may be referred to as component (A), "α-naphthol" as component (B), "carbonate" as component (C), "2,4-diaminophenoxyethanol or its salt" as component (D), and "toluene-2,5-diamine or its salt" as component (E). Furthermore, "2,2'-[(4-aminophenyl)imino]bisethanol" may be abbreviated as 2AP, "α-naphthol" as αNA, "2,4-diaminophenoxyethanol" as 2DA, and "toluene-2,5-diamine" as TDA. (Component (A): 2,2'-[(4-aminophenyl)imino]bisethanol or a salt thereof) The first agent of this embodiment is formulated with one or more 2,2'-[(4-aminophenyl)imino]bisethanol or its salt (component (A)). Examples of component (A) incorporated into the first agent of this embodiment include 2,2'-[(4-aminophenyl)imino]bisethanol salt (such as 2,2'-[(4-aminophenyl)imino]bisethanol sulfate (molecular weight: 294.32)) and 2,2'-[(4-aminophenyl)imino]bisethanol (molecular weight: 196.25). The amount of component (A) in the first agent of this embodiment is, for example, 0.001% by mass or more and 5.0% by mass or less. (2 AP amount) From the viewpoint of dyeing the hair a darker shade that includes a blue tint, the amount of 2,2'-[(4-aminophenyl)imino]bisethanol blended in the first agent of this embodiment (if 2,2'-[(4-aminophenyl)imino]bisethanol salt is blended, the amount is converted to 2,2'-[(4-aminophenyl)imino]bisethanol without the salt) (hereinafter, the amount of 2,2'-[(4-aminophenyl)imino]bisethanol may be referred to as "2AP amount") is preferably 0.01% by mass or more, and more preferably 0.1% by mass or more. In this embodiment, from the viewpoint of vividly dyeing hair with a blue tint, the amount of 2AP is preferably 4.0% by mass or less, and more preferably 3.0% by mass or less. From the above-mentioned viewpoint, the range of the 2AP amount in the first agent of this embodiment is preferably 0.0