Patent Number: 6,761,968

Title: Biaxially oriented polyester film

Abstract: A biaxially oriented polyester film which has excellent productivity while ensuring a transferred image having excellent shape reproducibility and gradation and is particularly suitable for use as a base film for a heat-sensitive transfer ribbon. This film is formed by simultaneous biaxial orientation and contains 0.1 to 2 wt % of inert inorganic particles having an average particle diameter of 0.5 to 5 .mu.m. This biaxially oriented polyester film has a value of 0.028 or less obtained by dividing the heat shrinkage factor (HS) (%) in a longitudinal direction at C. by the F-5 value (N/mm.sup.2) (F5) in the longitudinal direction measured at normal temperature (about C.) of the film.

Inventors: Kusume; Hiroshi (Sagamihara, JP), Furuya; Koji (Sagamihara, JP)

Assignee: Teijin Limited

International Classification: B29C 55/16 (20060101); B29C 55/12 (20060101); B32B 27/36 (20060101); B41M 5/40 (20060101); B41M 5/41 (20060101); C08J 5/18 (20060101); B32B 027/08 (); B32B 027/20 (); B32B 027/30 (); B32B 027/36 (); B32B 027/40 ()

Expiration Date: 07/12012