POLYVINYL ACETAL FILM WITH OUTSTANDING TRANSPARENCY AND RESISTANCE TO HEAT-CRACKING PHENOMENON
申请人:Kuraray Co., Ltd.
公开号:EP3029090A1
公开(公告)日:2016-06-08
An object is to provide a polyvinyl acetal film which has excellent transparency and can suppress a thermal cracking phenomenon.
The above object is achieved by providing a polyvinyl acetal film in which a ratio between a composite modulus (GPa) of the highest part in a convex part and a composite modulus (GPa) of the lowest part in a concave part on a surface of a film on a side in contact with glass, calculated by a nanoindentation measurement using a scanning probe microscope, is 0.90 or less, when a laminated glass is formed. In addition, the above object is achieved by providing a polyvinyl acetal film in which a ratio between a hardness (GPa) of the highest part in the convex part and a hardness (GPa) of the lowest part in the concave part, calculated by the SPM nanoindentation measurement, is 0.90 or less.
目的是提供一种聚乙烯醇缩醛薄膜,它具有优异的透明度,并能抑制热裂纹现象。
实现上述目的的方法是提供一种聚乙烯醇缩醛薄膜,当形成层压玻璃时,通过使用扫描探针显微镜进行纳米压痕测量,计算出薄膜与玻璃接触一侧表面上凸部最高部分的复合模量(GPa)与凹部最低部分的复合模量(GPa)之比为 0.90 或以下。此外,通过提供一种聚乙烯醇缩醛薄膜,其中通过 SPM 纳米压痕测量法计算出的凸面部分最高部分的硬度(GPa)与凹面部分最低部分的硬度(GPa)之比为 0.90 或更小,从而达到上述目的。