Process for the preparation of polyester polyols

US4845266A · kind A · utility

Assignee

• BASF SE

Inventors

• Matthias Marx · Fürstenfeldbruck, DE
• Joachim Jaehme · Ludwigshafen, DE
• Joachim Streu · Dachau, DE

Key dates

• Filing date: Apr 10, 1987
• Grant date: Jul 4, 1989
• Expiry date: Apr 10, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G63/87
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for the preparation of polyester polyols having an acid number of less than 1, a hydroxyl number of approximately 20 to about 400, and having a functionality of efficaciously 2 to 3, wherein polycarboxylic acids and/or their anhydrides and multivalent alcohols are polycondensed, preferably in the absence of common esterification catalysts, at temperatures of from about 150.degree. to 250.degree. C., optionally under reduced pressure, up to an acid number of from 20 to 5. The resulting polycondensate is then oxyalkylated per carboxyl group using from 1 to 5 moles of an alkylene oxide, for example 1,2-propylene oxide and/or preferably ethylene oxide, in the presence of at least one tertiary amine catalyst from the group consisting of N-methylimidazole, diazabicyclo[2,2,2]octane, diazabicyclo[5,4,0]undec-7-ene and pentamethyldiethylenetriamine and mixtures thereof, in a quantity of from about 0.001 to 1.0 weight percent based on the weight of the polycondensate, at temperatures from about 100.degree. to 170.degree. C. and under a pressure of about 1 to 10 bar.