Process for the preparation of carbonic acid aryl esters of polyester-diols lengthened via carbonate groups and their use for the preparation of polyester-diol bis-diphenol carbonates and polyester/polycarbonates

US4297455A · 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: May 30, 1978
• Grant date: Oct 27, 1981
• Expiry date: May 30, 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 aryl 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 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 obtained according to the instant invention and their use for the preparation of polyester diol bis-diphenol carbonates, lengthened via carbonate groups, characterized in that polyester-diol bis-aryl carbonates are reacted with a diphenol at a temperature of from about 100.degree. to about 200.degree. C. in vacuo below about 35 mm Hg in the presence of a catalyst, wherein more than 1 mo…