| 摘要 |
PROBLEM TO BE SOLVED: To obtain an SPS film excellent in thermal, physical, chemical and optical characteristics, having high dimensional stability and low haze and excellent also in transparency and flatness by specifying the amt. of residual metal Al from a polymn. catalyst for an SPS polymer. SOLUTION: This substrate is composed of a biaxially oriented SPS film having <=0.05wt.% residual metal Al content. The SPS film is a syndiotactic polystyrene(SPS)-based film and a film of a styrene polymer whose stereospecific structure (syndiotacticity) is chiefly a syndiotactic structure, that is, a steric structure with phenyl groups or substd. phenyl groups alternately positioned as side chains in the opposite directions to the principal chain consisting of C-C bonds or a compsn. contg. the styrene polymer. The principal chain is chiefly a racemic chain. |
