Patent ID: 6160049
Filing Date: 2000-12-12
Classification: C08F

Abstract:
A process for preparing an aqueous polymer dispersion by free-radically initiated polymerization of free-radically polymerizable compounds whose individual solubility in water under the conditions of the free-radically initiated polymerization is at least 0.001% by weight, based on the respective saturated aqueous solution (compounds I), whose disperse polymer particles comprise, in addition to the compounds I, at least one compound II whose solubility in water under the conditions of the free-radically initiated polymerization is less than 0.001% by weight, based on the respective saturated aqueous solution, and in which process a mixture consisting of a portion of the compounds I and of the at least one compound II is used to produce an oil-in-water emulsion I whose disperse phase consists predominantly of droplets with a diameter .ltoreq.500 nm, and in which at least a portion of the oil-in-water emulsion I is supplied continuously as a feed stream I to the polymerization vessel in the course of continuing free-radical polymerization, wherein the continuous feed stream I is accompanied by at least one feed stream II, with the proviso that the at least one feed stream II is a feed stream of another portion of the compounds I and/or is an oil-in-water emulsion II of another portion of the compounds I, whose disperse phase consists predominantly of droplets with a diameter .gtoreq.1000 nm.