Sekisui Kaseihin Kogyo Kabushiki Kaisha

Takeshi Taki

Takaaki Hirai

Norio Amano

Motoshige Hayashi

Masatoshi Ishibashi

A method of forming a thermoplastic polyester series foamed material having a thickness of at least 3 mm and an apparent density of from 0.05 to 0.7 g/cm.sup.3, wherein the crystallinity of the resin in the surface portion within 0.5 mm from the surface of the foamed material is not more than 30% and at least 1% lower than the crystallinity of the resin in the central portion of the foamed material.

Process for producing thermoplastic polyester series resin foamed

A thermoplastic polyester series foamed material having a thickness of at least 3 mm and an apparent density of from 0.05 to 0.7 g/cm.sup.3 is diclosed, wherein the crystallinity of the resin in the surface portion within 0.5 mm from the surface of the foamed material is not more than 30% and at least 1% lower than the crystallinity of the resin in the central portion of the foamed material.

Thermoplastic polyester series resin foamed material and production

A process of producing a thermoplastic polyester series resin foamed material is disclosed, which comprises heating and further foaming a thermoplastic polyester resin foamed material having a crystallinity of not higher than 30% by bringing it into contact with water or steam of at least 60.degree. C. and then heating the foamed material by bringing it into contact with a heating medium other than water of at least 100.degree. C. to further foam the foamed material. A process of producing a thermoplastic polyester series resin foamed material is also disclosed, which comprises heating and further foaming a thermoplastic polyester series resin foamed material having a crystallinity of not higher than 30% by bringing it into contact with water or steam of at least 60.degree. C., heating and further foaming the foamed material by bringing it into contact with a heating medium other than water of at least 100.degree. C., and molding the foamed material by a mold.

Process of producing thermoplastic polyester series resin foamed

A thermoplastic polyester series foamed material having a thickness of at least 3 mm and an apparent density of from 0.05 to 0.7 g/cm.sup.3 is disclosed, wherein the crystallinity of the resin in the surface portion within 0.5 mm from the surface of the foamed material is not more than 30% and at least 1% lower than the crystallinity of the resin in the central portion of the foamed material.

A process of producing a thermoplastic polyester series resin foamed material is disclosed, which comprises heating and further foaming a thermoplastic polyester resin foamed material having a crystallinity of not higher than 30% by bringing into contact with water or steam of at least 60.degree. C. and then heating the foamed material by bringing into contact with a heating medium other than water of at least 100.degree. C. to further foaming the foamed material. A process of producing a thermoplastic polyester series resin foamed material is also disclosed, which comprises heating and further foaming a thermoplastic polyester series resin foamed material having a crystallinity of not higher than 30% by bringing into contact with water to steam of at least 60.degree. C., heating and further foaming the foamed material by bringing into contact with a heating medium other than water of at least 100.degree. C., and molding the foamed material by a mold.

Process of producing thermoplastic polyester series resin foamed material

A process for producing a thermoplastic polyester resin foam comprising melting a thermoplastic polyester resin, mixing the molten resin with a blowing agent and extruding the mixture into a low-pressure zone to carry out expansion molding, characterized in that a compound having two or more acid anhydride groups per molecule, optionally together with a compound of a metal of Group I, II or III elements of the Periodic Table is added to the thermoplastic polyester resin. There is also disclosed a process for producing a thermoplastic polyester resin foam comprising cooling a high-temperature foam immediately after expansion and then re-heating the foam. Further, a thermoplastic polyester resin foam sheet and a food container prepared from the foam sheet are also disclosed.

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Nara, Japan

Takeshi Taki