Biodegradable film or sheet, process for producing the same, and composition for biodegradable film or sheet

摘要

The invention provides a biodegradable film or sheet having water resistance and strength sufficiently. Respective components are mixed so as to form a mixture containing 0% by mass or more and 35% by mass or less of starch, 20% by mass or more and 70% by mass or less of protein, 15% by mass or more and 60% by mass or less of cellulose fibers and 1% by mass or more and 15% by mass or less of urea, then adding 10 or more and 100 or less parts by mass of water to 100 parts by mass of the mixture, kneading the mixture sufficiently with a twin-screw mixer or the like, and rolling the kneaded product under heating at about 120° C. to give a film or sheet with several tens μm to about 300 μm in thickness.