LIQUID COMPOSITION FOR HAIR COLORING Russian patent published in 2022 - IPC A61K8/49 A61K8/34 A61Q5/10 

FIELD: hair coloring.

SUBSTANCE: liquid composition for hair coloring contains components (A) and (B), where content (X) of component (A) in the specified composition is equal to 1.8 wt.% or more and 4.0 wt.% or less, content (Y) of component (B) in the specified composition is equal to 20 wt.% or more and 85 wt.% or less. The specified composition satisfies the following equation: Y ≥ 22.75X – 22.75, provided that a liquid composition for hair coloring, in which diol content is equal to 50 wt.% or more, and water content is equal to 2 wt.% or less, is excluded. In this case, (A) is azo dye represented by the following formula:

(B) is one or several chemical substances selected from a group consisting of lower monoatomic alcohol with 2 or 3 carbon atoms, monocyclic aromatic monoatomic alcohol and diol with from 2 to 6 carbon atoms. A method for hair coloring is also disclosed.

EFFECT: group of inventions provides for the absence of precipitation of direct dyes during storage.

12 cl, 3 tbl, 5 ex