Process for reducing the residual monomer content in the polymerization of vinyl-lactams and vinyl esters

US4182851A · kind A · utility

Assignee

• BASF SE

Inventors

• Ferdinand Straub · Hockenheim, DE
• Herbert Spoor · Schifferstadt, DE
• Hans-Uwe Schenck · Monsheim, DE
• Wolfgang Schwarz · Ludwigshafen, DE

Key dates

• Filing date: Jun 27, 1978
• Grant date: Jan 8, 1980
• Expiry date: Jun 27, 1998

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F271/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for reducing the residual monomer content of a copolymer prepared by copolymerizing vinyl esters and N-vinyl-lactams in a solvent in the presence of a free radical polymerization initiator. Following the main polymerization, from 0.05 to 0.5% by weight, based on the monomers employed, of di-tert.-butyl peroxide, di-tert.-amyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis-(tert.-butylperoxy)-hexane, 2,2-bis-(tert.-butylperoxy)-butane, 1,1-bis-(tert.-butylperoxy)-3,3,5-trimethylcyclohexane, 4,4-di-(tert.-butylperoxy)-butyl valerate, or a mixture of these, is added to the reaction mixture and the after-polymerization is carried out at a higher temperature than the main polymerization.