Process for producing fluoropolymers having a reduced amount of polar end groups

US6812310B2 · kind B2 · utility

Assignee

• 3M INNOVATIVE PROPERTIES COMPANY · US

Inventors

• Werner M. A. Grootaert · Windom, US
• Klaus Hintzer · Woodbury, US
• Bernhard Hirsch · Altötting, DE
• Harald Kaspar · Altötting, DE
• Gernot Lohr · Altötting, DE
• Franz März · Altötting, DE
• Guy Van Gool · Melsele, BE

Key dates

• Filing date: Jun 2, 2003
• Grant date: Nov 2, 2004
• Expiry date: Jun 2, 2023

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F214/267
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A fluoropolymer having a reduced amount of polar end groups. The fluoropolymer is produced by free radical polymerization of fluorinated monomers and the initiation of the polymerization is carried out in the presence of a chloride salt. Polar end groups include hydroxy groups and ionized or ionizable end groups. Examples of ionized or ionizable end groups include acid groups and salts thereof such as sulfonic acid and salts thereof, —CH2—OSO3H groups, sulfates and carbonyl containing end groups such as carboxylic and carboxylate groups. Due to the presence of chloride salt at the initiation of the free radical polymerization, CF2Cl end groups are formed instead of the polar end groups. As a result, a fluoropolymer is obtained that has improved processibility and heat resistance.