Low monomer polyurethane prepolymer and process therefore

US6515164B1 · kind B1 · utility

Assignee

• Henkel Kommanditgesellschaft auf Aktien · DE

Inventors

• Gerd Bolte · Monheim, DE
• Guenter Henke · Neuss, DE
• Markus Kruedenscheidt · Langenfeld, DE
• Astrid Omoruyi · Goldkronach, DE

Key dates

• Filing date: Jul 2, 1999
• Grant date: Feb 4, 2003
• Expiry date: Jul 2, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G18/7621
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A low-monomer PU prepolymer containing free NCO groups which is obtained from polyhydric alcohols and diisocyanates differing in their reactivity and which is distinguished by the ratio of the NCO groups of the partly slower-reacting diisocyanate to the NCO groups of the faster-reacting diisocyanate. It is greater than 6:1. Nevertheless the prepolymer according to the invention cures more quickly than a known prepolymer predominantly containing fast-reacting NCO groups. In a preferred embodiment, TDI is used as the partly slower-reacting diisocyanate while MDI is used as the faster-reacting diisocyanate. The prepolymer is produced in two stages. The prepolymer according to the invention is suitable for bonding plastic articles, metals and paper, especially films. The accelerated absence of migration is particularly noticeable in this regard.