| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to obtain a syndiotactic polystyrene(SPS) film having excellent thermal, physical, chemical and optical characteristics and high dimensional stability by biaxially orienting the SPS film having the weight average mol.wt. of a specific numerical value or above of the SPS. SOLUTION: This base for photographic sensitive materials is formed of the biaxially oriented SPS film having the weight average mol.wt. of >=350,000 of the SPS. The film consisting essentially of the SPS is a styrene polymer of which the stereoregular structure mainly has a syndiotactic structure and of which the principal chain of the main chain is a racemo chain or a compsn. contg. the same. The more specific monomer of the polymer consisting the SPS compsn, include independent monomers consisting essentially of alkyl styrene, such as styrene or methyl styrene, styrene halide, such as chloromethyl styrene, alkoxy styrene, vinyl benzoate, etc., or mixtures composed thereof. |
