Copolymers containing carboxyl groups and, if appropriate, tertiary amino groups, a process for their preparation and their use in coating materials

US5276104A · kind A · utility

Assignee

• Basf Lacke & Farben Aktiengesellschaft · DE

Inventors

• Peter Hoffmann · Senden, DE
• Werner-Alfons Jung · Ascheberg, DE

Key dates

• Filing date: Dec 5, 1991
• Grant date: Jan 4, 1994
• Expiry date: Dec 5, 2011

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L63/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to copolymers containing carboxyl groups and having an acid number of 20 to 150 mg of KOH/g and a number average molecular weight of 2000 to 8000, which can preferably be prepared from copolymers containing hydroxyl groups by reaction with carboxylic anhydrides, to a process for their preparation and their use in coating agents. The copolymers contain a vinyl ester, a vinyl aromatic, a hydroxyalkyl ester of an .alpha.,.beta.-unsaturated carboxylic acid, and optionally other monomers that may contain acid groups. The vinyl ester is taken initially and the other monomers are metered during the course of a monomer addition time of equal length for all monomers, in the following manner: PA0 1) the amount of the hydroxyalkyl ester added per time unit remains constant, and PA0 2) the amount of the vinyl aromatic added within the first third of the monomer addition time is 15 to 30% by weight, that added within the second third is 25 to 40% by weight, and that added within the last third is 35 to 60% by weight, in each case relative to the total amount of vinyl aromatic.