THE METHOD OF PRODUCING POLYESTER SHEET IMPROVED ON VACUUM EVAPORATION FORCE

摘要

PURPOSE: A process for manufacturing a polyester sheet by coating a water dispersion coating solution composition containing colloidal alumina particles and polymer resin on the surface of polyester sheet prepared by using a polyester having the adequate extent of limiting viscosity, glass transition point and crystallization temperatures as a film base material is provided which does not generate environmental pollution by an organic solvent. CONSTITUTION: The process comprises a coating of water dispersion coating solution composition containing 0.1-1.0 weight% of colloidal alumina with a particle size of 20-50 nm, 0.01-2 weight% of water soluble polyester resin, 0.01-2 weight% of water soluble polyurethane resin, and 0.01-2 weight% of water soluble acrylic emulsion on one or more sides of sheet formed by uniaxial or biaxial orientation of copolyester composed of ethyleneterephthalate above 60% of repeating unit, having a limiting viscosity of 0.6-1.0 dl/g, a glass transition point of 75-85C and a crystallization temperature of 170-190C. In coating the water dispersion coating solution composition, residual solid matters are 0.001-0.1 g/m¬2 after drying. The polyester has improved transparency and deposition strength.