FIELD: chemistry.
SUBSTANCE: present invention relates to a polyester film characterised by excellent recyclability for reuse. Polyester film contains a resin of a copolymerised polyester, wherein diol and an aromatic dicarboxylic acid are copolymerised. The crystallisation temperature (Tc) of the film is immeasurable or equal to 70-130°C. During heat treatment at 210°C for 90 minutes, the degree of clumping of the flakes produced by crushing a polyethylene terephthalate (PET) container equipped with the polyester film is 10% or less. Method for producing a polyester film includes: producing a resin of a copolymerised polyester; extruding the melt of the resin of a copolymerised polyester at a temperature of 250 to 300°C so as to produce an unstretched sheet and stretching the unstretched sheet at a temperature of 70 to 100°C, followed by curing said sheet by heating at a temperature of 65 to 90°C to produce a polyester film. Method for reclamation of a polyethylene terephthalate container includes: providing a PET container equipped with a polyester film; crushing the PET container to produce flakes; and subjecting said flakes to heat treatment to produce reclaimed polyester chips.
EFFECT: development of a polyester film exhibiting excellent shrinkage characteristics due to the controlled degree of crystallinity and excellent recyclability for reuse; non-uniform clumping occurs rarely even in the case of drying thereof at high temperatures for a long period of time in the process of heat treatment thereof.
9 cl, 6 dwg, 4 tbl, 16 ex
