Biaxially oriented polyester film
AssigneeTeijin Limited
InventorsMakoto Handa, Tomoyuki Kishino
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Abstract
The present invention provides a biaxially oriented polyester film made of a polyester containing 0.01 to 5% by weight of crosslinked polymer particles characterized by: (1) having a particle size distribution ratio (.gamma.) of 1.3 to 3.5, (2) having an average particle diameter of 0.1 to 2 .mu.m, (3) having a non-circularity of 3.4 or more, and (4) having a standard deviation of noncircularity, of at least 0.16. The polyester film of the present invention has a flat surface having a small number of large protuberances, excellent running property and excellent winding property, and can be produced economically. The film has excellent properties for use as a base for various magnetic recording media.
Claims15
A biaxially oriented polyester film formed of a polyester containing 0.01 to 5% by weight of crosslinked polymer particles characterized by:
- (1) having a particle size distribution ratio (.gamma.) of 1.3 to 3.5,
- (2) having an average particle diameter of 0.1 to 2 .mu.m,
- (3) having a non-circularity of 3.4 or more, and
- (4) having a standard deviation of non-circularity, of at least 0.16.
Dependencies are inferred from the claim text.