Process for the manufacture of aqueous ethylene/vinyl chloride/vinyl alkanoate and/or alkyl acrylate copolymer dispersions having a non-uniform particle size distribution

US4247438A · kind A · utility

Assignee

• Wacker Chemie AG · DE

Inventors

• Herbert Eck · Burghausen, DE
• Klaus Hafener · Burghausen, DE
• Hubert Wiest · Burghausen, DE

Key dates

• Filing date: Aug 2, 1979
• Grant date: Jan 27, 1981
• Expiry date: Aug 2, 1999

Classification

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

Abstract

Aqueous ethylene/vinyl chloride/vinyl alkanoate and/or alkyl acrylate copolymer dispersions having a non-uniform particle size distribution, in which one particle size distribution maximum is at 0.03 to 0.2.mu. and a second maximum is at 0.15 to 1.mu. and in which 5% to 60% by weight of the particles belong to the amount of particles having said second maximum, which are produced by free-radical polymerization at 0.degree. to 90.degree. C., while stirring, in the presence of emulsifiers which, in amounts of 0.5% to 15% by weight, calculated on the final solid resin, are not added until a polymerization conversion of 1% to 60% by weight of the total amount of monomer has been reached. The copolymer dispersions have solids contents of 20% to 70% by weight of copolymer comprising 20% to 92% by weight of vinyl chloride, 5% to 60% by weight of ethylene and 3% to 75% by weight of vinyl esters and/or acrylic acid esters, and, optionally, up to 15% by weight of other monomers copolymerizable with ethylene and vinyl chloride, said monomers being metered into the polymerization mixture together with the emulsifiers during the manufacturing process.