Patent · US Active

Dyeing method for keratin fibers comprising a direct azo-dye and an organic alkalizing agent, and kit-of-parts thereof

US12383480B2 · kind B2 · utility

0Cited by

1References

20Claims

0Family size

Assignee

KAO CORPORATION · JP

Inventors

Bernd Nöcker · Darmstadt, DE
Steven Breakspear · Darmstadt, DE
Fariba Ghiasi · Darmstadt, DE
Anna Neu · Darmstadt, DE

Key dates

Filing date	Dec 20, 2022
Grant date	Aug 12, 2025
Priority date	—
Expiry date	Dec 20, 2042

Classification

Technology area (CPC A)Human Necessities
CPC primaryA61K2800/88
WIPO fieldPharmaceuticals
WIPO sectorChemistry

Abstract

A method for dyeing keratin fibers, including mixing an aqueous dyeing composition containing a dye compound which is an anionic azo dye, a non-ionic azo dye, a salt thereof, or a mixture thereof, and an alkalizing agent having at least one basic functional group whose conjugated acid has a pKa value in a range of 6.0 to 8.0, with a second aqueous composition having a pH in a range of 1 to 6 to yield a ready-to-use composition having a pH in a range of 7 to 12. The method further includes applying the ready-to-use composition onto the keratin fibers and leaving it for a time period in a range of 1 min to 60 min, and rinsing-off the keratin fibers. The alkalizing agent is triethanolamine, 2-[4-(2-hydroxyethyl)-piperazin-1-yl]-ethane-1-sulfonic acid, a salt thereof, or a mixture thereof.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.