Copolymers containing hydroxyl groups, based on vinyl ester monomers, vinylaromatic monomers and hydroxylalkyl ester monomers, process for the preparation thereof and use thereof in coating compositions

US5322897A · kind A · utility

Assignees

• BASF Lacke · DE
• Farben AG · DE

Inventors

• Werner-Alfons Jung · Ascheberg, DE
• Udo Vorbeck · Ascheberg, DE

Key dates

• Filing date: Dec 19, 1990
• Grant date: Jun 21, 1994
• Expiry date: Dec 19, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G18/6254
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to copolymers containing hydroxyl groups having a hydroxyl value of 50 to 200 mg of KOH/g and an average molecular weight (number average) of 1500 to 6000, which can be prepared by free-radical solution polymerization at temperatures of 130.degree. to 200.degree. C. of 5 to 25% by weight of vinyl ester monomers, 10 to 50% by weight of vinylaromatic monomers, 10 to 50% by weight of hydroxyalkyl ester monomers and, if desired, other monomers, in which the vinyl ester is initially used and the remaining monomers are added over a monomer addition period which is the same for all monomers as follows: PA1 i) The amount of the acrylate monomer added per unit time remains constant. PA1 ii) The amount of the vinylaromatic hydrocarbon added over the first third of the monomer addition period is 15 to 30% by weight, preferably 18 to 26% by weight, that added over the second third is 25 to 40% by weight, preferably 30 to 38% by weight, and that added over the last third is 35 to 60% by weight preferably 40 to 50% by weight, of the total amount of the vinylaromatic hydrocarbon. The subject-matter of the invention is also a process for the preparation of the copolymers as w…