METHOD FOR TREATING POLYMERIZATION MEDIUM CONTAINING CARBOXYLATED FLUOROCARBON COPOLYMER

• Main Authors: ASAKAWA AKIHIKO, WASHIDA HIROSHI
• Format: Patent
• Language: English
• Published: 14.04.1998
• Edition: 6
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

PROBLEM TO BE SOLVED: To obtain a good-quality resin for coating materials by bringing a polymerization solution of a carboxylated fluorocarbon copolymer into contact with a (mixed) resin having anion- and cationexchange groups to remove a residual alkali material and unsaturated carboxylic acid therefrom. SOLUTION: A carboxylated fluorocarbon copolymer containing a medium obtained by copolymerizing a fluoroolefin (A) with an unsaturated carboxylic acid (B) and other monomers (D) in a polymerization medium containing an alkali metal compound (E) is brought into contact with a resin having cation- and anion-exchange groups or a mixed resin to remove component E and residual component B therefrom. The polymerization medium used is a hydrophilic solvent or water. Component E is exemplified by K2 CO3 , NaHCO3 or NaOH. The amphoteric ion-exchange resin is exemplified by those of styrene resin or methacrylic resin type. Accroding to this method, a carboxylated fluorocarbon resin copolymer can be freed from impurities which adversely affect the copolymer when it is used in a varnish or a coating material.