Free-radical polymerization process producing aqueous polymer dispersion with low residual monomer content utilizing oil and water soluble initiators

US8034885B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Jun Gao · Mountain View, US
• Xiang-Ming Kong · Mainz, DE
• Klaus-Dieter Hungenberg · Birkenau, DE
• Juergen Schmidt-Thuemmes · Schifferstadt, DE

Key dates

• Filing date: Jul 8, 2004
• Grant date: Oct 11, 2011
• Expiry date: Sep 9, 2027

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F2/22
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention provides a novel one-step process for preparing an aqueous polymer dispersion by the free radical aqueous emulsion polymerization comprising mixing at least water, a dispersant, and an oil-soluble initiator; raising a temperature from the starting to the end reaction temperature while metering at least ethylenically unsaturated monomers and a water-soluble initiator into a reaction vessel, conducting polymerization of the monomers in the presence of the water-soluble initiator at a temperature up to the end reaction temperature, and when the temperature has reached the end reaction temperature, conducting polymerization by the oil-soluble initiator. The oil-soluble initiator is inactive at the starting reaction temperature and becomes more active as a temperature approaches the end reaction temperature at which the oil-soluble initiator is fully active.