Production of rigid polyurethane foams

US5552450A · kind A · utility

Assignee

• BASF SE

Inventors

• Werner Hinz · Bischofswerda, DE
• Rolf Henn · Ketsch, DE
• Uwe Keppeler · Hochdorf-Assenheim, DE
• Bernd Guettes · Sallgast, DE

Key dates

• Filing date: Apr 18, 1994
• Grant date: Sep 3, 1996
• Expiry date: Apr 18, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G2110/0041
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for the production of rigid polyurethane foams involves reacting PA1 a) organic and/or modified organic polyisocyanates with PA1 b) at least one relatively high-molecular-weight compound containing at least two reactive hydrogen atoms, and, if desired, PA1 c) low-molecular-weight chain extenders and/or cross-linking agents, in the presence of PA1 d) blowing agents, PA1 e) catalysts and, if desired, PA1 f) assistants and/or additives, where the relatively high-molecular-weight compounds (b) containing at least two reactive hydrogen atoms are polyoxypropylene-polyols and/or polyoxyethylene-polyoxy-propylene-polyols containing up to 20% by weight, based on the weight of the alkylene oxide units, of pendant oxyethylene units containing secondary hydroxyl groups and having a functionality of from 3.8 to 4.1, a hydroxyl number of from 385 to 410 mg of KOH/g and a viscosity of from 1700 to 2400 mPa.multidot.s at 25.degree. C., and which can be prepared by anionic polymerization of 1,2-propylene oxide and, if desired, ethylene oxide on an initiator molecule mixture comprising sucrose, pentaerythritol and diethylene glycol.