Process for the production of rigid polyurethane foams

US5223549A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Rolf Wiedermann · Bensberg, DE
• Gerhard Heilig · Bensberg, DE
• Wolfgang Schmitz · Puchheim, DE

Key dates

• Filing date: Aug 13, 1991
• Grant date: Jun 29, 1993
• Expiry date: Aug 13, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S521/906
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Rigid polyurethane foams are produced by reacting a polyisocyanate with a polyester containing at least two isocyanate-reactive hydrogen atoms and having a molecular weight of 400 to 10,000 in the presence of water, an organic blowing agent, a flameproofing agent and a compound containing at least two isocyanate-reactive hydrogen atoms and having a molecular weight in the range from 32 to 399 as crosslinking agent, optionally in the presence of known auxiliaries and additives. The polyester, the flameproofing agent and the crosslinking agent are used in quantities such that from about 15 to about 35 parts by weight of polyester, from about 50 to about 80 parts by weight flameproofing agent and from about 5 to about 15 parts by weight of crosslinking agent (with the sum of the parts by weight of these components adding up to 100) are present. These foams are useful as insulating materials in applications where flame resistance is important.