可塑剤含有ポリビニル（イソ）アセタールからの部分層を含有する減衰特性を有する薄膜積層体

摘要

The film laminate comprises three layers A, B and C, where each of the layers contains a plasticizer and a polyvinyl acetal. Two outer layers A and C contain same or different polyvinyl acetal (23 wt.%) with a proportion of polyvinyl alcohol groups of 18.5-23 wt.%. An inner layer B is a polyvinyl acetal having a proportion of polyvinyl alcohol groups of 12-18 wt.%. One of the layers A, B or C contains polyvinyl(iso)acetal, and polyvinyl(n)acetal. The polyvinyl(iso)acetal results from a reaction of polyvinyl alcohol with aliphatic keto compounds having 4-10C. The film laminate comprises two outer layers A and C, and an inner layer B, where each of the layers contains a plasticizer and a polyvinyl acetal. The outer layers contain same or different polyvinyl acetal (23 wt.%) with a proportion of polyvinyl alcohol groups of 18.5-23 wt.%. The inner layer is a polyvinyl acetal having a proportion of polyvinyl alcohol groups of 12-18 wt.%. One of the layers contains polyvinyl(iso)acetal, and polyvinyl(n)acetal. The film laminate is produced by coextrusion and merging of the layers. The polyvinyl(iso)acetal results from a reaction of polyvinyl alcohol with aliphatic keto compounds having 4-10C with a branch at alpha -position or beta -position to a keto group and with aliphatic, unbranched keto compound having 2-10C. The outer layers contain same or different polyvinyl(iso)acetal, and same or different polyvinyl(n)acetal. The inner layer B comprises a different polyvinyl(iso)acetal.