Patent ID: 6433079
Filing Date: 2002-08-13
Classification: C08F

Abstract:
A water-dilutable polyvinylbutyral dispersion obtained by a two-stage reaction comprising:1. reacting at least one tertiary alkanolamine A and at least one diisocyanate B â€ƒto the theoretically calculated NCO content wherein the amounts of components A and B are chosen such that the amount of substance of the diisocyanates B is from about 0.8 to about 1.3 times the amount of substance of the reactive hydroxyl groups in A. 2. reacting until all of the isocyanate groups have undergone complete reaction a polyvinylbutyral C in partial solution in a solvent which is inert towards isocyanates with the adduct AB from the first step to form the product ABC wherein the number of hydroxyl groups in C being at least about ten times the number of isocyanate groups in the reaction product AB, and combining this solution of the amine-modified polyvinylbutyral ABC, optionally, with one or more compatible plasticizing resins D which is or are likewise water-dilutable by way of tertiary amino groups, the resin mixture containing mass fractions of solids of (based in each case on resin solids)i) from about 20 to 100% of modified polyvinylbutyral ABC and ii) from 0 to about 80% of the suitable plasticizing resin D or of a mixture of two or more such suitable plasticizing resins with the proviso that the sum of i)+ii) is 100% and the resulting resin mixture has tertiary amino groups corresponding to an amine number of from about 20 to about 80 mg/g resin solids and, following neutraliation, by diluting the product with deionized water, at least about 50% of the tertiary amino groups of the amine-modified polyvinylbutyrals ABC with (in)organic acids.