Polyester foamed articles and method for producing the same
AssigneeShowa Highpolymer Co., Ltd.
InventorsHaruhiko Kondo, Mitsuhiro Imaizumi, Ryosuke Kamei, Hideharu Kimura, Eiichiro Takiyama
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Abstract
A method for producing polyester foamed articles comprising: heating and foaming a resin composition comprising a foaming agent, and 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. Extrusion or forming in a mold using preexpanded beads can be applied. The foamed articles such as insulating boxes and cushioning materials have biodegradability and excellent mechanical properties such as tensile strength and cushioning properties.
Claims22
A method for producing polyester foamed articles comprising:
- obtaining a prepolymer having a number-average molecular weight of at least 10,000 from a reaction of at least an aliphatic glycol and an aliphatic dicarboxylic acid, wherein the reaction includes (a) succinic acid, or its derivatives, reacted with 1,4-butanediol, (b) succinic acid, adipic acid, or their derivatives, reacted with 1,4-butanediol, or (c) succinic acid, or its derivatives, reacted with ethylene glycol;
- adding from 0.1 to 5 parts by weight of diisocyanate to 100 parts by weight of the prepolymer in a molten state to obtain a crystalline 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.;
- adding a foaming agent to the crystalline 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.;
- then
- heating and foaming.
Expandable polyester beads comprising:
- 100 parts by weight of a crystalline 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.;
- and 0.5-40 parts by weight of a volatile foaming agent;
- 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 derivatives, reacted with 1,4-butanediol, (b) succinic acid, adipic acid, or their derivatives, 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.
An insulated box or cushioning medium formed by heating and foaming a resin composition consisting of a foaming agent and a crystalline 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 derivatives, reacted with 1,4-butanediol, (b) succinic acid, adipic acid, or their derivatives, 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.