Process for preparing perfluoropolyoxyalkylenes with -OCF2H, -OCF2CF2H and -OCF(CF3)H end groups

US6858757B2 · kind B2 · utility

Assignee

• SOLVAY SOLEXIS S.P.A. · IT

Inventors

• Giuseppe Marchionni · Milano, IT
• Gianfranco Spataro · Lissone, IT

Key dates

• Filing date: May 21, 2003
• Grant date: Feb 22, 2005
• Expiry date: May 21, 2023

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C41/48
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for preparing perfluoropolyoxyalkylenes having —OCF2H, —OCF2CF2H and —OCF(CF3)H end groups and a number average molecular weight from 120 to 3,000, by decarboxylation of the corresponding perfluoropolyoxyalkylenes having —OCF2COOH, —OCF2CF2COOH, —OCF(CF3)COOH end groups, in the presence of catalytic amounts of salts formed by perfluoropolyoxyalkylenes having end groups selected from —OCF2COOZ, —OCF2CF2COOZ and —OCF(CF3)COOZ, wherein Z is a monovalent cation of the group Ia or Ib or Z is —NR4+ wherein R is hydrogen or a C1-C4 alkyl, using ratios between Z and the —COOH equivalents of the perfluoropolyoxyalkylenes to be decarboxylated from 0.01 to 0.08, at a temperature between 120° C. and 180° C., in the presence of water, at pH <5 and at a pressure comprised between 2 and 80 atmospheres.