Production of rigid polyurethane foams

US5895792A · kind A · utility

Assignee

• BASF SE

Inventors

• Udo Rotermund · Ortrand, DE
• Renate Hempel · Ruhland, DE
• Holger Seifert · Bad Driburg, DE
• Werner Wiegmann · Rahden, DE

Key dates

• Filing date: Sep 23, 1997
• Grant date: Apr 20, 1999
• Expiry date: Sep 23, 2017

Classification

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

Abstract

In a process for producing rigid polyurethane foams having improved heat distortion resistance and reduced thermal conductivity by reacting PA1 a) polyisocyanates with PA1 b) compounds containing hydrogen atoms reactive toward isocyanates, in the presence of PA1 c) water, and, if desired, PA1 d) physically acting blowing agents and PA1 e) catalysts and known auxiliaries and/or additives, the compounds b) containing hydrogen atoms reactive toward isocyanates are a polyol mixture comprising PA1 b1) a polyol which can be prepared by addition of ethylene oxide and/or propylene oxide onto a hexitol or a hexitol mixture, with the total hexitol content of the polyol mixture being from 15 to 30% by weight, based on the polyol mixture, and PA1 b2) a polyol which can be prepared by addition of ethylene oxide and/or propylene oxide onto one or more aromatic amines, with the total amine content of the polyol mixture being from 1 to 10% by weight, based on the polyol mixture, and the amount of the polyol mixture in the component b) is from 60 to 100 parts by mass per 100 parts by mass of the component b).