Process for the preparation of thermoplastic aromatic polyphosphonates with improved thermal ageing resistance

US4374971A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Manfred Schmidt · Krefeld, DE
• Dieter Freitag · Krefeld, DE
• Ludwig Bottenbruch · Krefeld, DE

Key dates

• Filing date: Oct 27, 1980
• Grant date: Feb 22, 1983
• Expiry date: Oct 27, 2000

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G79/04
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for the preparation of a linear or branched-chain thermoplastic aromatic polyphosphonate having an average molecular weight (number average M.sub.n) in the range of from 11,000 to 200,000, which comprises solvent-free ester interchange of at least one diaryl phosphonate or at least one diaryl phosphonate and at least one triaryl phosphate with at least one aromatic dihydroxy compound or at least one aromatic dihydroxy compound and at least one aromatic tri- or tetra-hydroxy compound or a mixture thereof in an oxygen-free gas atmosphere at atmospheric pressure or reduced pressure, with removal of the volatile constituents by distillation, and in the presence of a catalytic quantity of an ester interchange catalyst which comprises at least one compound taken from the group, C.sub.1 -C.sub.18 tetraalkyl titanates, C.sub.2 -C.sub.4 dialkyl tin oxides, C.sub.2 -C.sub.4 -di-alkyl-C.sub.1 -C.sub.4 -dialkoxy tin compounds, C.sub.3 -C.sub.18 tetraalkyl zirconates and C.sub.2 -C.sub.18 trialkyl vanadylates, antimony or bismuth salts, C.sub.2 -C.sub.4 dialkyl stannic acid esters, C.sub.2 -C.sub.4 trialkyl stannic acid esters, or a mixture of at least one compound from the above grou…