Patent · US Expired

Two-stage process for dyeing keratin fibres

US4425132A · kind A · utility

68Cited by
2References
31Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 5, 1979
Grant dateJan 10, 1984
Priority date
Expiry dateApr 5, 1999

Classification

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

Abstract

A two-stage process for dyeing keratin fibres, especially human hair, is described which involves treating the fibres with a first composition at a first pH and subsequently, without rinsing treating the fibres with a second composition at a second pH, at least one of the compositions containing a dyestuff for the fibres, and the second pH being different from the first pH so as to modify the effect of at least one active ingredient on the fibres.

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