Polyester sheet
AssigneeShowa Highpolymer Co., Ltd.
InventorsMitsuhiro Imaizumi, Masataka Kotani, Haruhiko Kondo, Takeshi Iwasa, Eiichiro Takiyama
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Abstract
A sheet formed by using as a main component an aliphatic polyester having a melt viscosity of 1.0.times.10.sup.3 -1.0.times.10.sup.6 poises at a temperature of 190.degree. C. and a shear rate of 100 sec.sup.-1, and having a melting point of 70.degree.-190.degree. C. The sheet of the present invention is biodegraded when buried in soil and is excellent in mechanical properties and transparency. The sheet is also superior in non-absorbency of aroma as well as heat-sealability and formability.
Claims9
A polyester sheet comprising an aliphatic polyester having a melt viscosity of 1.0.times.10.sup.3 -1.0.times.10.sup.6 poises at a temperature of 190.degree. C. and a shear rate of 100 sec.sup.-1, and having a melting point of 70.degree.-190.degree. C.,
- wherein said aliphatic polyester is obtained by adding from 0.1 to 5 parts by weight of diisocyanate to 100 parts by weight of a prepolymer in a molten state,
- wherein said prepolymer is obtained from a reaction of at least an aliphatic glycol and an aliphatic dicarboxylic acid, wherein the reaction includes (a) succinic acid, or its anhydrides, reacted with 1,4-butanediol, (b) succinic acid, adipic acid, or their anhydrides, reacted with 1,4-butanediol, or (c) succinic acid, or its derivatives, reacted with ethylene glycol, and
- has a number-average molecular weight of at least 10,000.
Dependencies are inferred from the claim text.