Process for the preparation of carbonic acid aryl esters of polyester-diols lengthened via carbonate groups

US4217297A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Christian Lindner · Bensheim, DE
• Carlhans Suling · Odenthal, DE
• Herbert Bartl · Odenthal, DE
• Manfred Schreckenberg · Krefeld, DE
• Dieter Freitag · Krefeld, DE
• Klaus Konig · Leverkusen, DE

Key dates

• Filing date: Mar 13, 1978
• Grant date: Aug 12, 1980
• Expiry date: Mar 13, 1998

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G63/64
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for the preparation of bis-carbonic acid monoaryl esters of polyester-diols, lengthened via --OCOO-- groups, characterized in that polyester-diols with molecular weights Mn (number-average) of over 250, preferably over 600, are heated with carbonic acid bis-aryl esters at temperatures between about 100.degree. C. and 200.degree. C., preferably between about 110.degree. C. and 180.degree. C., in vacuo below about 35 mm Hg, preferably between about 25 and 1 mm Hg, in the presence of catalysts, less than one mol of carbonic acid bis-aryl ester being employed per mol of OH group of the polyester-diol and the hydroxyaryl compounds formed being distilled off. The invention further relates to the bis-carbonic acid aryl esters of polyester-diols lengthened via --OCOO-- groups.