Preparation of hard foams containing urethane groups or urethane and isocyanurate groups by polyisocyanate polyaddition, and polyoxyalkylene-polyols which are suitable therefor

US5192813A · kind A · utility

Inventors

• Rolf Henn · Ketsch, DE
• Werner Hinz · Bischofswerda, DE
• Ludwig Schuster · Schifferstadt, DE
• Klaus Vorspohl · Stockach, DE

Key dates

• Filing date: May 2, 1991
• Grant date: Mar 9, 1993
• Expiry date: May 2, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S521/902
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for the preparation of a hard foam containing urethane groups or urethane and isocyanurate groups by the polyisocyanate polyaddition process, by reacting PA1 a) a polyoxypropylene- or polyoxyethylene-polyoxypropylene-polyol containing secondary hydroxyl groups, having a functionality of from 3.5 to 4.3, a hydoxyl number of from 350 to 650 and a viscosity of from 500 to 2,500 mPa.s at 23.degree. C. and prepared by anionic polymerization of 1,2-propylene oxide or ethylene oxide and 1,2-propylene oxide onto an initiator molecule mixture containing, based on the total weight, PA1 a1) from 40 to 80% by weight of a hexanetetrol, PA1 a2) from 1 to 30% by weight of a hexanetriol, PA1 a3) from 0 to 35% by weight of glycerol and PA1 a4) from 0 to 15% by weight of sorbitol or mannitol, or a mixture thereof, PA1 b) optionally, a low-molecular-weight chain extender and/or crosslinking agent with PA1 c) an organic, modified or unmodified polyisocyanate; in the presence of PA1 d) a blowing agent, PA1 e) a catalyst and, optionally, PA1 f) assistants and/or additives, and novel polyoxypropoylene-polyols and polyoxyethylene-polyoxypropylene-polyols which ca…