Process for dyeing polyurethane plastics

US4026931A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Manfred Wiesel
• Richard Sommer
• Georg Pape · Leverkusen, DE
• Michael Kressner · Leichlingen, DE

Key dates

• Filing date: Jul 25, 1975
• Grant date: May 31, 1977
• Expiry date: Jul 25, 1995

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B29/3613
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process for dyeing polyurethane plastics is disclosed in which an azo dyestuff derived from an indole or 5-aminopyrazole coupling component and containing at least one group having an active hydrogen atom, e.g. hydroxyl aor amino, is introduced during the reaction forming the polyurethane whereby the dyestuff is bonded to the polyurethane by a covalent bond resulting from reaction of the active hydrogen on the dyestuff with a polyurethane reaction component, e.g. polyisocyanate. The dyed polyurethanes produced by this process having a very high level of fastness, e.g. fastness to bleeding upon overcoating.