To provide a manufacturing method for a film which is composed of a fumaric diester polymer, and which is excellent in transparency, surface smoothness, thickness precision and mechanical strength.
The film is manufactured by a solution casting method in which a polymer solution, consisting of the fumaric diester polymer and an organic solvent, is cast on a supporting substrate, and in which the solvent is evaporated from a cast film containing the solvent. In the manufacturing method for the transparent film, the organic solvent is a mixture solvent which consists of a 95-5 wt.% aromatic solvent and a 5-95 wt.% nonaromatic solvent; the polymer solution is a fumaric diester polymer solution, the polymer concentration of which is in the range of 15-50 wt.%; and solution viscosity measured at 30°C is in the range of 1,000-50,000 cP.
COPYRIGHT: (C)2007,JPO&INPIT
Kenichi Makita
Toi Doi
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