Polyester film and method for reproducing polyester container using same

Abstract

The embodiments relate to a. polyester film and a process for regenerating a polyester container using the same, which not only solve the environmental problems by improving the recyclability of polyester containers, but also are capable of enhancing the yield and productivity. The polyester film comprises a first layer comprising a first resin comprising a diol component and a dicarboxylic acid component; and a second layer laminated on one side of the first layer and comprising a second resin different from the first resin, wherein when the polyester film is cut with a polyethylene terephthalate container to form flakes and the flakes are thermally treated at a temperature of 200° C. to 220° C. for 60 minutes to 120 minutes, the clumping fraction is 8% or less.

1 . A polyester film to be regenerated with a polyester container, which comprises:
 a first layer comprising a first resin comprising a diol component and a dicarboxylic acid component; and   a second layer laminated on one side of the first layer and comprising a second resin different from the first resin,   wherein when the polyester film is cut with a polyethylene terephthalate container to form flakes and the flakes are thermally treated at a temperature of 200° C. to 220° C. for 60 minutes to 120 minutes, the clumping fraction is 8% or less.   
     
     
         2 . The polyester film to be regenerated with a polyester container of  claim 1 , which has a heat shrinkage rate of 30% or more in the main shrinkage direction upon thermal treatment at a temperature of 80° C. for 10 seconds. 
     
     
         3 . The polyester film to be regenerated with a polyester container of  claim 1 , wherein when the second layer is laminated on the first layer with an organic solvent, the bonding force of the laminated portion is 600 gf or more. 
     
     
         4 . The polyester film to be regenerated with a polyester container of  claim 1 , wherein the second resin comprises a resin having a weight average molecular weight of less than 10,000 or a resin having a weight average molecular weight of greater than 12,000. 
     
     
         5 . The polyester film to be regenerated with a polyester container of  claim 1 , wherein the second resin is a polyethylene naphthalate-based resin. 
     
     
         6 . The polyester film to be regenerated with a polyester container of  claim 1 , which further comprises a third layer laminated on the other side of the first layer and comprising a third resin different from the first resin, 
     
     
         7 . The polyester film to be regenerated with a polyester container of  claim 6 , wherein the second resin and the third resin are the same as each other. 
     
     
         8 . The polyester film to be regenerated with a polyester container of  claim 6 , wherein when the second layer is laminated on the third layer with an organic solvent, the bonding force of the laminated portion is 200 gf or more. 
     
     
         9 . A process for regenerating a polyester container, which comprises:
 providing the polyester container and a heat-shrunken polyester film that wraps at least part of the polyester container;   crushing the polyester container and the heat-shrunken polyester film to obtain flakes; and   thermally treating the flakes to produce regenerated polyester chips, wherein when the flakes are thermally treated at a temperature of 200° C. to 220° C. for 60 minutes to 120 minutes, the clumping fraction is 8% or less, the flakes comprise first flakes obtained by crushing the container and second flakes obtained by crushing the heat-shrunken polyester film, and the heat-shrunken polyester film comprises a first layer comprising a first resin comprising a diol component and a dicarboxylic acid component; and a second layer laminated on one side of the first layer and comprising a second resin different from the first resin,   
     
     
         10 . The process for regenerating a polyester container of  claim 9 , wherein the particle size of the first flakes is 0.1 to 25 mm, and the particle size of the second flakes is 0.1 to 25 min. 
     
     
         11 . The process for regenerating a polyester container of  claim 9 , wherein the container comprises polyethylene terephthalate in an amount of 90% by weight or more. 
     
     
         12 . Regenerated polyester chips prepared according to the regeneration process of  claim 9 .