To inexpensively provide a polyglycolic acid sheet which has excellent toughness, barrier properties and other properties and in addition is degradable in soil.
This polyglycolic acid sheet comprises a polyglycolic acid comprising repeating units represented by formula (1). A thermoplastic resin material contg. a polyglycolic acid having (a) a melt viscosity η0 of 500 to 100,000Pa.s as measured at a temp. of m.p. Tm+20°C and a shear rate of 100/sec, (b) an m.p. Tm of 150°C or above, (c) a melt enthalpy ΔHm of not less than 20J/g, and (d) a density of a nonaligned crystallization product of not less than 1.50g/cm3 is melt extruded in the temp. range of Tm to 255°C into a sheet. The sheet has a tensile strength of not less than 60MPa. The process for preparing a polyglycolic acid sheet comprises the steps of: melt extruding the thermoplastic resin material in the temp. range of Tm to 255°C through a T die into a sheet; rapidly cooling the sheet to a temp. of the crystallization temp. Tc1 or below; and optionally heat setting the cooled sheet.
SATO NOBUO
HOSHINO MITSURU
KAYAMA TOSHITAKA
SHIIKI YOSHIYA
