Patent ID: 6114423
Filing Date: 2000-09-05
Classification: C08F,C08J,C09D,D06M,Y02P

Abstract:
A crosslinkable dispersion powder comprising water-insoluble copolymers of ethylenically unsaturated monomers and, optionally, further additives which are redispersible in water obtained bya) emulsion polymerizing, at a pH of 2 to 9,(i) a comonomer mixture comprising at least one comonomer selected from the group consisting of vinyl esters of unbranched or branched alkylcarboxylic acids having 1 to 18 carbon atoms, methacrylic acid esters of unbranched or branched alcohols having 1 to 18 carbon atoms, acrylic acid esters of unbranched or branched alcohols having 1 to 18 carbon atoms, olefins, dienes, vinylaromatics and vinyl halides, and(ii) 0.05 to 15.0% by weight, based on the total weight of the comonomer mixture, of at least one silicon compound of the formulaCH.sub.2 .dbd.CH--(CH.sub.2).sub.m --SiR(OR').sub.2,where m=0-8,CH.sub.2 .dbd.CR""--CO.sub.2 --(CH.sub.2).sub.n SiR(OR').sub.2where n=1-6, ##STR5## wherein R is a branched or unbranched C.sub.1 -C.sub.12 alkyl group or a phenyl group, R' is an identical or different branched, unbranched or cyclic C.sub.2 -C.sub.6 alkyl group, optionally substituted with a C.sub.1 -C.sub.2 alkoxy group, or two R's within the formula SiR(OR').sub.2 forming a bridge having the formulas ##STR6## wherein R"" is H or CH.sub.3, to form an aqueous dispersion; and b) spray drying said aqueous dispersion, at a pH of 4 to 8 at a discharge temperature of 55 to 100 C, before or after addition of any additive.