Image-forming transfer material including a polyester film
AssigneesDiafoil Hoechst Company, Limited, Mitsubishi Chemical Corporation
InventorsYoshinori Sato, Tetsuya Masuda
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Abstract
A polyester film for an image-forming transfer material, wherein a difference .DELTA..alpha..sub.t between the maximum coefficient of thermal expansion and the minimum coefficient of thermal expansion in the film plane is not larger than 1.0.times.10.sup.-5 /.degree.C., and the maximum coefficient of thermal expansion .alpha..sub.tmax is not larger than 2.5.times.10.sup.-5 /.degree.C., which can form a high quality color image having less deviation and a high image density.
Claims17
An image-forming transfer material comprising a polyester film, wherein a difference .DELTA..alpha..sub.t between the maximum coefficient of thermal expansion and the minimum coefficient of thermal expansion in the film plane is not larger than 1.0.times.10.sup.-5 /.degree.C., and the maximum coefficient of thermal expansion .alpha..sub.tmax is not larger than 2.5.times.10.sup.-5 /.degree.C., wherein said polyester is prepared from an aromatic dicarboxylic acid or its ester and a glycol selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol and neopentyl glycol, and wherein said polyester film has a birefringence of not larger than 0.030 and an average refractive index of at least 1.595.
The image-forming transfer material according to claim 4, wherein said surface roughness Ra is at least 0.003 .mu.m.
Dependencies are inferred from the claim text.