| 摘要 |
PROBLEM TO BE SOLVED: To obtain a resin film which is excellent in thickness precision, contains little bubbles, and has good optical properties by dissolving a synthetic resin in a solvent with stirring in a container of a helium atmosphere, casting the solution of the resin on a support, and drying the solution. SOLUTION: Methylphenyl ether is placed in a stirring container in which air is replaced with helium in advance, and polysulfone pellets which are divided into four portions are added to the ether with stirring. After the stirring being continued until the complete dissolution of the pellets, the mixture is allowed to stand to eliminate bubbles while the helium atmosphere being kept. The solution is cast onto a polyimide film using a comma coater to obtain a polysulfone cast film. |
