PURPOSE: To prevent the happening of the trouble caused by particles in shaved matter by specifying the wt. ratio of polyester of the shaved matter of the surface of a polyester film.
CONSTITUTION: The number of surface projections formed on the surface of a polyester film is set to 5000/mm2 or more and the relative standard deviation of height distribution is set to 0.80 or less, pref., 0.75 or less. Even if the projections are shaven off by the surface unevenness of a contact partener, by setting the wt. ratio of polyester in shaved matter to 0.90 or more, pref., 0.95 or more, more pref., 0.98 or more, the problems caused by the particles in the shaved matter such as the surface contamination of the contact partner, a rise of the coefficient of friction or a film injuring, especially, a scratch injury in a high speed process are eliminated. When the wt. ratio of polyester in the shaved matter is smaller than 0.90, it is not pref. because particles shaven off by friction damage the film deeply and widely.
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