MANUFACTURING METHOD OF POLYESTER FILM FOR MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method to manufacture stably a polyester film for magnetic recording medium of excellent quality in spite of being high in productivity while solving such a problem of a production loss at switching time of sorts of film that has been actualized accompanying the diversification of specifications of polyester films for magnetic recording medium and capable of reducing the production loss at switching time of sorts of film. SOLUTION: A wire bar of a roughness from 4.4μm to 5.8μm on the surface at the points in contact with the polyester film is used as the wire bar in the method to manufacture the polyester film for a magnetic recording medium containing a water soluble polymer membrane on the surface where a ferromagnetic metal film is formed by drying and stretching after coating with water solution containing a water soluble polymer on the one side of a polyester film stretched in one direction using a coating equipment that controls the coating amount with the wire bar so as to make the solid material painting density from 10 to 50 mg/m2.