HIGH OXYGEN GAS BARRIER TRANSPARENT LAMINATED POLYESTER FILM AND ITS MANUFACTURE AS WELL AS PACKAGING MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a high oxygen gas barrier biaxially oriented polyester film having excellent physical properties similar to those of a publicly known film without problem of discarding by simply manufacturing by a low cost. SOLUTION: The biaxially oriented laminated polyester film comprises a base layer made of 80% or more of thermoplastic polyester and at least one coating layer in such a manner that the coating layer is formed of a mixture of 40 wt.% or more of ethylene-2,6-naphthalate unit, 40 wt.% or less of ethylene terephthalate unit and 60 wt.% or less of alicyclic diol and/a mixture of aromatic diol and polymer made of a unit derived from dicarboxylic acid or polymer and second glass transition temperature (Tg2) of the polyester film is higher than that (Tg2) of the base layer and lower than the second glass transition temperature (Tg2) of the coating layer.