Abstract: 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 ?m to about 300 ?m in thickness.

Abstract: The present invention provides a processed biodegradable article having excellent water resistance and rigidity, which can be used as a food container, and a biodegradable composition required to produce the processed biodegradable article comprising 15-75% by mass starch, 5-50% by mass protein, 3-50% by mass cellulose fiber, 0.5-20% by mass polyphenols such as pyrogallol and gallic acid, and 0-5% by mass sodium chloride.

Abstract: The present invention provides a processed biodegradable article having excellent water resistance and rigidity, which can be used as a food container, and a biodegradable composition required to produce the processed biodegradable article. The respective components are mixed such that the content of starch is 15% by mass or more and 75% by mass or less, the content of protein is 5% by mass or more and 50% by mass or less, the content of cellulose fiber is 3% by mass or more and 50% by mass or less, the content of polyphenols is 0.5% by mass or more and 20% by mass or less, and the content of sodium chloride is 0% by mass or more and 5% by mass or less, and then water is added in the amount of 10 parts by mass or more and 100 parts by mass or less based on 100 parts by mass of the mixture, followed by kneading the mixture using a mixer. Then, the kneaded mixture is press-molded into a predetermined shape such as a cup or a dish, and heat-treated at 120° C. or higher and 180° C.

Abstract: 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 ?m to about 300 ?m in thickness.