Patent ID: 6235843
Filing Date: 2001-05-22
Classification: C08F,C08J,Y10T

Abstract:
A process for the preparation of crosslinkable dispersion powders which are redispersible in water and contain isocyanate groups, comprising copolymerizing by free-radical emulsion polymerization, one or more ethylenically unsaturated monomers in the presence of 0.2 to 6% by weight, based on the total weight of the monomers, of one or more ethylenically unsaturated isocyanates selected from the group consisting of meta- and para-isopropenyl-alpha, alpha-dimethylbenzylisocyanate and isocyanates of the general formula (I)CH.sub.2.dbd.CR.sup.1 --CO--O--R.sup.2 --CR.sup.3 R.sup.4 --N.dbd.C.dbd.O (I)where R.sup.1 is H or CH.sub.3, and R.sup.2 is an alkylene group having 1 to 18 C atoms, and R.sup.3 and R.sup.4 are identical or different alkyl groups having 1 to 4 C atoms; and drying the dispersions obtained by said copolymerization, wherein said emulsion polymerization and said drying are carried out in the presence of 5 to 70% by weight, based on the total weight of the monomers, of a protective colloid.