| 摘要 |
PROBLEM TO BE SOLVED: To provide a member for a transmission type screen without causing environmental pollution even after using a member by using biodegradation resin as base material. SOLUTION: The members for the transmission type screen such as a lenticular lens, a Fresnel lens, a contact screen, a diffusion panel and the front panel of a display are formed by using the biodegradation resin as material. Then, polylactic acid base resin is a desirable concrete example as the biodegradation resin, and it is desirable to use the resin which is principally composed of poly- L-lactic acid and whose weight average molecular weight is >=100,000. If flexibility is insufficient as the material of the member for the transmission type screen in the case of using the polylactic acid base resin alone, lactic acid is made a hard segment, and copolymerized with a soft segment monomer or prepolymer, whereby the polylactic acid base resin excellent in the flexibility is obtained. Since the polylactic acid base resin is composed of starch, it is decomposed into water and carbon dioxide gas in the earth even when it is discarded after it is used.
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