A protective film for optical disks comprising an acrylic adhesive layer disposed on one face of a light transmitting substrate film, wherein a change in transmittance (X) expressed by equation [1] is 10% or smaller and the amount of elution of halogen ions and the amount of alkaline ions from an acrylic adhesive constituting the acrylic adhesive layer are each 10 ppm or smaller; and an optical disk using the protective film.X(%)=[(Ta-Tb)/Ta]×100 (Ta: an initial transmittance of light of 405 nm through the protective film, Tb: a transmittance of light of 405 nm through the protective film after the protective film is left standing at 80°C in 85% RH for 1,000 hours)
The protective film is used for protecting the information recording layer of the optical disk and the functions of recording and regeneration of the optical disk are not adversely effected.
一种用于光盘的保护膜,包括设置在透光基底薄膜的一个面上的
丙烯酸粘合剂层,其中用等式[1]表示的透射率变化(X)为 10%或更小,构成
丙烯酸粘合剂层的
丙烯酸粘合剂的卤素离子洗脱量和碱性离子量各为 10 ppm 或更小;以及使用该保护膜的光盘。X(%)=[(Ta-Tb)/Ta]×100(Ta:保护膜的初始透光率 405 纳米,Tb:保护膜在 85% 相对湿度下于 80°C 条件下放置 1,000 小时后保护膜的透光率 405 纳米)。
保护膜用于保护光盘的信息记录层,不会对光盘的记录和再生功能产生不利影响。