PROCESS FOR PRODUCING POLYESTER SHEET EXCELLENT IN FORMABILITY AND INFRARED RAY EMITTING EFFECT

摘要

PURPOSE: Provided is a process for producing an amorphous polyester sheet excellent in formability and infrared rays-emitting effect, wherein the polyester sheet can be used as a food container excellent in storage ability for a long time. CONSTITUTION: The process comprises the steps of: adding 5-50wt% of an infrared ray-emitting body having an average particle size of 0.2-7.0 micrometer to a polyester resin having an intrinsic viscosity of 0.5-0.7dl/g, and mixing and dispersing to prepare a master batch resin; heating and drying the master batch resin at 100-150deg.C for 3.0-5.0 hours; forming the multi-layered amorphous sheet containing 1.0-10.0g/m2 of the infrared ray-emitting body in a core layer or a sub layer by using a co-extruder, wherein the amorphous sheet has more than 80% of a spectral radiation rate in the infrared radiation zone(lambda is 4-25 micrometer). The infrared ray-emitting body is at least one of yellow soil, quartz porphyry, and ceramic and contains SiO2, Al2O3, MgO, (K.H3O)Al2(Si.Al)4O10(H2O.OH)2, and etc.