LAMINATE FILM AND TRANSPARENT SUBSTRATE

PROBLEM TO BE SOLVED: To provide a new laminate film which is excellent in thermal dimensional stability at high temperatures, has high smoothness of a surface of at least one film and can suppress warpage of a film.SOLUTION: There is provided a laminate film which comprises a heat-resistant resin layer A on one surface side of a substrate film and a heat-resistant resin layer B on the other surface side, where the heat-resistant resin layer A is a cured resin layer containing fine particles having an average particle diameter of 1 to 200 nm at a ratio of 40 to 70 vol.% in the layer and having a thickness of 4 to 15% of the thickness of the substrate film and the heat-resistant resin layer B positioned on the opposite side to the heat-resistant resin layer A through the substrate film is a cured resin layer which contains no fine particles or contains fine particles having an average particle diameter of 1 to 200 nm at a ratio of 10 vol.% or less in the layer and has a thickness of 200 to 400% of the thickness of the heat-resistant resin layer A. 【課題】 高温における熱寸法安定性に優れていて、少なくとも一方のフィルム表面の平滑性が高く、フィルムの反りも抑制できる、新たな積層フィルムを提供する。【解決手段】基材フィルムの一方の面側に耐熱性樹脂層Ａ，他方の面側に耐熱性樹脂層Ｂを備えた積層フィルムであって、耐熱性樹脂層Ａは、平均粒子径が１ｎｍ〜２００ｎｍの範囲にある微粒子を該層中に４０体積％〜７０体積％の割合で含有し、且つ、基材フィルムの厚みの４％〜１５％の厚みを有する硬化樹脂層であり、基材フィルム介して耐熱性樹脂層Ａとは反対側に位置する耐熱性樹脂層Ｂは、微粒子を含有しないか或いは平均粒子径が１ｎｍ〜２００ｎｍの範囲にある微粒子を該層中に１０体積％以下の割合で含有し、且つ、前記耐熱性樹脂層Ａの厚みの２００％〜４００％の厚みを有する硬化樹脂層であることを特徴とする積層フィルムを提案する。【選択図】なし