Patent ID: 8920930
Filing Date: 2014-12-30
Classification: B32B,Y10T

Abstract:
1. A film laminate, comprising at least three layers A, B and C, each containing at least one plasticizer and at least one uncrosslinked polyvinyl acetal, wherein two outer layers A and C each comprising at least one identical or different polyvinyl acetal having a proportion of polyvinyl alcohol groups of 18.5 to 23% by weight one or more inner layer(s) B comprising a polyvinyl acetal having a proportion of polyvinyl alcohol groups of 12 to 18% by weight, and wherein at least one of the layers A, B or C is a polyvinyl iso-acetal layer, wherein the film laminate satisfies at least one of the following conditions I and II: I. said polyvinyl acetal of layer B is polyvinyl iso-butyral and said polyvinyl acetal of layer A or C is polyvinyl n-butyral II. said polyvinyl acetal of layer B is polyvinyl n-butyral and said polyvinyl acetal of layer A or C is polyvinyl iso-butyral.