Patent ID: 8431047
Filing Date: 2013-04-30
Classification: B32B,C04B,C08F,C08L,Y10T

Abstract:
1. A polyvinyl acetal resin composition, which comprises a polyvinyl acetal resin A and a polyvinyl acetal resin B incompatible with said polyvinyl acetal resin A, which is formed by acetalizing a mixed polyvinyl alcohol containing two or more kinds of polyvinyl alcohols having different saponification degrees, and wherein said mixed polyvinyl alcohol contains main two kinds of polyvinyl alcohols in which X and Y satisfy the relationship of the following equation (1): in which X represents the saponification degree of any one polyvinyl alcohol a of the polyvinyl alcohols contained in the mixed polyvinyl alcohol and Y represents the saponification degree of a polyvinyl alcohol b other than the polyvinyl alcohol a, and wherein in denoting, by M, the polymerization degree of one polyvinyl alcohol having a higher polymerization degree of said main two kinds of polyvinyl alcohols and denoting the polymerization degree of the other polyvinyl alcohol by N, M and N have the relationship of the following equation (2): and a phase composed of said polyvinyl acetal resin A and a phase composed of said polyvinyl acetal resin B form a sea-island structure.