Process for the preparation of fluorocarbon polymers containing carboxyl groups, and certain starting materials required for this, and the fluoro-sulfato compounds formed as intermediate products in the process

US4471076A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Peter Blickle · Hofheim, DE
• Johannes Brandrup · Wiesbaden, DE
• Hans Millauer · Eschborn, DE
• Werner Schwertfeger · Altötting, DE
• G/u/ nter Siegemund · Hofheim, DE

Key dates

• Filing date: Feb 16, 1983
• Grant date: Sep 11, 1984
• Expiry date: Feb 16, 2003

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F2800/10
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Substantially non-crosslinked fluorocarbon polymers containing carboxyl groups are prepared starting from non-crosslinked and in some cases new, fluorocarbon polymers in which the linear macromolecules carry side chains containing the end group --CHFX (X is F or CF.sub.3). The starting polymers are first reacted with peroxodisulfuryl difluoride FSO.sub.2 O--OSO.sub.2 F to give the corresponding fluorosulfato derivatives containing the side chain end groups. ##STR1## In the event that X is F, these derivaties are then converted into the corresponding carboalkoxy derivatives by means of an alcohol, the fluorosulfato group being split off, and these carboalkoxy derivatives are then converted by saponification into the products containing the free carboxyl groups; the fluorosulfato derivatives can also be hydrolyzed with water, if appropriate in the presence of an inert solvent and/or bases, to give, without further treatment, the products containing the free carboxyl groups. The fluorosulfato derivatives in which X is CF.sub.3 in the side chain end groups are first decomposed in the presence of catalytic amounts of alkali metal fluorides and/or aprotic nitrogen bases to give the produ…