申请人:Kuraray Co., Ltd.
公开号:EP2366750A1
公开(公告)日:2011-09-21
A non-crosslinking type adhesive composition for an optical film is provided that has excellent adhesion to a substrate, allows peeling to be carried out at a suitable peeling strength without leaving an adhesive residue, has excellent reworking properties, can maintain good adhesion properties for a long time, and has excellent durability. The adhesive composition for an optical film includes an acrylic triblock copolymer, which does not have an NCO functional group, and an isocyanate compound. The acrylic triblock copolymer (I), which is represented by the formula A1-B-A2, is formed by alkyl methacrylate polymer blocks A1 and A2 having a Tg of 100°C or more and an alkyl acrylate polymer block B having a Tg of -20°C or less, wherein the content of the block B is 40 to 95 mass%, Mw is 50,000 to 300,000, and the molecular weight distribution is 1.0 to 1.5. Based on the mass of the solids in the adhesive composition, the content of the acrylic triblock copolymer (I) is 60 mass% or more, and the content of the isocyanate compound is 0.0015 mass% or more to less than 0.35 mass% in terms of NCO group content.
本发明提供了一种光学薄膜用非交联型粘合剂组合物,该组合物对基材具有极佳的粘合性,可在适当的剥离强度下进行剥离而不会留下粘合剂残留物,具有极佳的再加工性能,可长时间保持良好的粘合性能,并且具有极佳的耐久性。用于光学薄膜的粘合剂组合物包括不含 NCO 官能团的丙烯酸三嵌段共聚物和异氰酸酯化合物。丙烯酸三嵌段共聚物 (I) 由式 A1-B-A2 表示,由 Tg 为 100°C 或以上的甲基丙烯酸烷基聚合物嵌段 A1 和 A2 以及 Tg 为 -20°C 或以下的丙烯酸烷基聚合物嵌段 B 组成,其中嵌段 B 的含量为 40 至 95%,Mw 为 50,000 至 300,000,分子量分布为 1.0 至 1.5。根据粘合剂组合物中固体的质量,丙烯酸三嵌段共聚物 (I) 的含量为 60 质量%或以上,异氰酸酯化合物的含量为 0.0015 质量%或以上至小于 0.35 质量%(以 NCO 基含量计)。