Toyobo Co., Ltd.

Yukio Yamane

Hiroshi Nagano

Tsutomu Isaka

Koichi Matsunami

Tetsushi Murakami

A transparent polyester film having excellent printability, flexing resistance and pinhole resistance and further excellent interlaminar strength, which is made from a polymer mixture or blend comprising (i) a polyester consisting essentially of a residue of dibasic acids wherein at least 80 % by mol is terephthalic acid and a residue of at least one glycol and (ii) a block copolyester consisting of a crystalline polyester (hard) segment having a high melting point and a soft polymer segment having a low melting point and a number average molecular weight of 400 to 8,000, said soft polymer segment having a low melting point being contained in an amount of 0.5 to 10 % by weight on the basis of the whole weight of the polymer mixture or blend, and said crystalline polyester segment having a melting point of at least 170.degree. C when a polymer is produced by the monomers composing the segment alone and said soft polymer segment having a melting or softening point of 100.degree. C or lower.

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Otsu, Japan

Yukio Yamane