| 摘要 |
PROBLEM TO BE SOLVED: To improve flexibility, prevent split or crack from occurring caused by bending stress and shearing stress, and prevent chip from being produced in cutting, etc., by extending polynorbornene resin film containing plasticizer. SOLUTION: A phase-difference film is formed by extending a polynorbornene resin film containing plasticizer. Especially, a resin formed by adding hydrogen to the ring-opening polymer of norbornene monomer is preferable, because it is an amorphous polymer so as to be easily formed into an optically uniform film. The weight average molecular weight of the polynorbornene resin is preferable to be 5,000-1,000,000, more preferably 8,000-200,000. The contained plasticizer is not specially prescribed, if only it is eliminated from being compatible with the resin or causing bleading-out, whitening, and foaming by heating for drying and extension. The blending ratio of the plasticizer is preferable to be 1-15 pts.wt. in relation to the polynorbornene based resin 100 pts.wt., more preferably within 2-5 pts.wt. |
