Patent ID: 7786233
Filing Date: 2010-08-31
Classification: C08F

Abstract:
1. A polyvinylpyrrolidone powder composition comprising polyvinylpyrrolidone with a K value of not lower than 50 and not higher than 120, wherein a content of insoluble substances remaining on a membrane filter having a pore size of 1.2 μm when a 2 wt % aqueous solution of the composition is filtered with the filter is not higher than 70 ppm, and wherein the polyvinylpyrrolidone powder composition is produced by filtering a reaction solution after completion of polymerization and then drying by means of a heating surface adhesion-type drying method, a freeze drying method, or a vacuum drying method, wherein the polyvinylpyrrolidone powder composition does not contain a secondary amine or a salt thereof.