Process for preparing heat-resistant polyurethane elastomers having no secondary softening range

US4098773A · kind A · utility

Assignee

• BASF Wyandotte Corporation · US

Inventors

• Karl H. Illers · Otterstadt, DE
• Herbert Stutz · Karlsruhe, DE

Key dates

• Filing date: Oct 8, 1976
• Grant date: Jul 4, 1978
• Expiry date: Oct 8, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G2250/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention concerns a process for making heat-resistant polyurethane elastomers from substantially linear polyhydroxyl compounds of high molecular weight, polyisocyanates, chain extenders, and, if desired, catalysts and additives, in which the polyhydroxyl compound is reacted with diisocyanate material in amounts to give an OH:NCO ratio of 1:1.10 to 1:2 and produce an adduct, and the adduct is subsequently reacted with symmetrical aromatic diisocyanate and a diol as chain extender (preferably a linear diol containing 2,4 or 6 carbon atoms) to obtain a crystalline or crystallizable diurethane or polyurethane of good heat resistance.