| 摘要 |
PURPOSE:To improve transparency, adhesiveness to glass, impact resistance, biodegradability and molding properties, etc., of a polyvinylactal resin composition by blending a specific polyvinylacetal resin and poly(epsilon-caprolactone) together. CONSTITUTION:The specific polyvinylacetal resin is obtained by acetalizing PVA having a 300 to 3000 average degree of polymerization with an aldehyde compound having <=11 carbon atoms in 40 to 85mol% degree of acetalization. 55 to 95 pts.wt. of the polyvinyl acetal resin and 45 to 5 pts.wt. of the poly(epsilon-caprolactone) represented by the formula, wherein n is 10 to 2000, are blended together by heating and melting them at 100 to 200 deg.C to obtain the objective polyvinylacetal resin composition. Alternatively, they are blended together by dissolving them into a solvent and thereafter the solvent is removed by evaporating it to obtain the resin composition. At the time of using the polyvinylacetal resin composition as an intermediate film for the laminated glass, the polyvinylacetal resin has preferably a 50 to 85mol% degree of acetalization and the blending ratio of the poly(epsilon-caprolactone) is preferably 10 to 40 pts.wt. Further an ultraviolet absorber, ultraviolet stabilizer and antioxidant are added to the polyvinylacetal resin composition at need and the resulting composition is melted and kneaded and then formed into a film having 0. 1 to 2.0mm thickness to be used as the intermediate film for the laminated glass. |
