Process for the continuous production of an ethylene/vinyl acetate copolymer dispersion

US4035329A · kind A · utility

Assignee

• Wacker Chemie AG · DE

Inventors

• Hubert Wiest · Burghausen, DE
• Josef Hanzalik
• Wilhelm Lechner · Burghausen, DE
• Erwin Lieb

Key dates

• Filing date: Nov 19, 1975
• Grant date: Jul 12, 1977
• Expiry date: Nov 19, 1995

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F210/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for the continuous manufacture of an aqueous ethylene/vinyl acetate copolymer dispersion which comprises continuously copolymerizing ethylene and vinyl acetate and optionally other .alpha.-olefinically unsaturated monomers, in an aqueous emulsion in the presence of an emulsifier and/or a protective colloid, and in the presence of a free-radical-forming redox catalyst system of a reducing agent and an oxidizing agent as well, optionally, as a heavy metal salt, and recovering said ethylene/vinyl acetate copolymer dispersion, characterized by (a) the presence of a molar excess of at least 3 times, preferably from 3 to 10 times, said reducing agent over said oxidizing agent dosed into the reaction medium and (b) adding the monomers continuously to the reaction mixture at such a rate that the concentration of unreacted monomers at no place in the reaction zone exceeds 15% by weight of the total weight of the reaction mixture.