A film for optical parts exhibiting high transmittance of short-wavelength light on the order of 400 nm, low birefringence, and excellent flexibility in which warping can be prevented after use for a long term, and a coiled film laminate using the film for optical parts, and an optical parts and an optical discs. The film for optical parts is characterized by comprising a light transmitting layer principally comprising thermosetting resin where an integrated value of the ratio of loss modulus to storage modulus in a temperature range of 30°C to 80°C as determined by a dynamic viscoelasticity measurement under a tensile stress mode at a frequency of 10 Hz with a heating rate of 3°C/min is 2 or more.
一种光学部件用薄膜,具有 400 nm 左右的短波长光的高透射率、低双折射、长期使用后可防止翘曲的优异柔韧性,以及使用该光学部件用薄膜的卷膜层压板、光学部件和光盘。光学部件用薄膜的特征是包括一个主要由热固性
树脂组成的透光层,该透光层在 30°C 至 80°C 的温度范围内,损失模量与存储模量之比综合值为 2 或 2 以上,该损失模量是在频率为 10 Hz、加热速度为 3°C/min 的拉伸应力模式下,通过动态粘弹性测量测定的。