To provide biodegradable foams such as foamed sheets, containers and pellets which have a hot water-resistant temperature of ≥80°C, required temperature for hot food containers and are highly safe and excellent in warmth retention and heat insulation.
The foam is a crystalline and biodegradable polyester-based resin foam which has a hot water-resistant temperature of ≥80°C and a ratio of foaming by carbon dioxide closed cells of 4-50 times, and contains a crystallization nucleation agent having an average particle size of ≤1 μm. Preferably, the polyester-based resin includes an aromatic polyester resin in an amount of at least ≥30 wt.% of the total weight of the resin. Preferably, the crystallization nucleation agent is not deteriorated under supercritical or subcritical carbon dioxide condition. Preferably, the crystallization nucleation agent is an inorganic substance.
KIDO HIROSHI
TAKAOKA SHIGERU
KONISHI REIICHI
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