Preparation of chlorofluorocarbon-free flexible polyurethane foams using diphenylmethane diisocyanate-based polyisocyanate mixtures containing urethane groups, and modified polyisocyanate mixtures

US5597885A · kind A · utility

Assignee

• BASF SE

Inventors

• Heinz-Dieter Lutter · Diepholz, DE
• Bernd Bruchmann · Ludwigshafen, DE
• Claudia Spang · Eisenberg, DE
• Roland Minges · Havelsee, DE
• Dietrich Scherzer · Neustadt, DE
• Michael Lugmayr · Puchheim, DE
• Ruth Zschiesche · Mannheim, DE

Key dates

• Filing date: Jun 7, 1995
• Grant date: Jan 28, 1997
• Expiry date: Jun 7, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G2110/0083
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the preparation of CFC-free, flexible polyurethane foams or molded foams by reacting PA1 A) liquid polyisocyanate mixtures containing bonded urethane groups and having a content of NCO groups of from 20 to 30% by weight, these mixtures themselves being prepared by reacting a mixture of diphenylmethane diisocyanates and polyphenyl-polymethylene polyisocyanates (crude diphenylmethane diisocyanate) with a polyether-polyol mixture, having a hydroxyl number of from 120 to 25, of at least one polyoxypropylene glycol and at least one trifunctional polyoxypropylene-polyoxyethylene glycol having a content of ethylene oxide units of from 90 to 10% by weight or by reacting 4,4'-diphenylmethane diisocyanate (diphenylmethyl diisocyanate) or an diphenylmethane diisocyanate isomer mixture with said polyether-polyol mixture to give an NCO-containing quasi-prepolymer and diluting this quasi-prepolymer with crude diphenylmethane diisocyanate, with PA1 B) relatively high-molecular-weight polyhydroxyl compounds.