| 摘要 |
The present invention relates to a method for producing a norbornene optical film. More specifically, the method comprises the following steps: producing a film by emulsifying a norbornene-based resin in a solution, wherein the norbornene-based resin is represented by chemical formula 1 and includes a recurring unit comprising an elongation improved monomer (B) and a polymerization improved monomer (M); elongating the produced film at a predetermined temperature of 140 to 250°C; and relaxing the film to a temperature (T) within a range expressed by equation 1, (extension temperature+5)(B/M)^b <= T <= (extension temperature+7)(B/M)^b. According to the present invention, a bowing phenomenon of the norbornene film is controlled, so an optical axis of a phase difference film can be controlled. In the chemical formula 1, R_1 is hydrogen, or a formyl group substituted by an alkoxy group having 1 to 2 carbons. R_2 is a formyl group substituted by an alkoxy group having 4 or more carbons, or an acetoxy methyl group. m and n are respectively integers of 1 or more. In the equation 1, the measure of the extension temperature and the T is °C. The B/M is a mole ratio of the elongation improved monomer (B) and the polymerization improved monomer (M). The b is -0.094. |
