Disclosed is an optical film produced by a method comprising continuously discharging a molten resin on a casting roll through a die lip of an extruder, wherein the molten resin contains a copolymer of (A) 75 to 99% by weight of an (meth)acrylate monomer that, when homopolymerized, has a negative intrinsic birefringence, and (B) 1 to 25% by weight of an (meth)acrylate monomer that, when homopolymerized, has a positive intrinsic birefringence, and a velocity ratio V2/V1 of 1.2 to 15 is satisfied wherein V1 represents a discharge velocity of the molten resin from the die lip, m/min; and V2 represents a surface velocity of the casting roll, m/min.
公开了一种光学薄膜的生产方法,该方法包括通过挤出机的模唇连续排放浇铸辊上的熔融
树脂,其中熔融
树脂含有(A)75-99%(重量)的(甲基)
丙烯酸酯单体的共聚物,该单体在均聚时具有负的本征双折射,以及(B)1-25%(重量)的(甲基)
丙烯酸酯单体,该单体在均聚时具有负的本征双折射、(B)1-25%(按重量计)的(甲基)
丙烯酸酯单体,该单体在均聚时具有正的本征双折射,速度比 V2/V1 为 1.其中 V1 表示熔融
树脂从模唇排出的速度,米/分;V2 表示浇铸辊的表面速度,米/分。