Teijin Limited

Tomio Adachi

Hideo Katoh

Shigeru Shiozaki

Takashi Tomie

Yukio Mitsuishi

Atsushi Yamamoto

Takashi Tanabe

Rikuo Miura

Hideaki Kawakami

A magnetic recording medium composed of an oriented polyethylene terephthalate film as a support layer and a thin magnetic metallic layer formed on one surface (A) of the support layer and optionally a lubricant layer formed on the other surface (B) of the support layer; characterized in that

Magnetic recording medium

A polyester film characterized by having many uneven units on its surface, each of said uneven units being composed of a fine projection and a depression existing therearound, and a process for producing aforesaid polyester film, which comprises pre-heating an unstretched polyester film containing internal particles attributed to an inert additive having an average particle diameter of 0.05 to 5 .mu.m and/or a catalyst residue to a temperature of 80.degree. to 120.degree. C.; stretching the film in a first axial direction to 2.6 to 3.5 times at a temperature of 110.degree. to 145.degree. C.; thereafter, stretching the film in a second axial direction at right angles to the first axial direction to 3.0 to 4.0 times at a temperature of 100.degree. to 150.degree. C.; and then heat-setting the stretched film at a temperature of 160.degree. to 240.degree. C.

Polyester film with projections and depressions on the surface

A magnetic recording material formed from a base film of a crystalline polymer and having a magnetic layer coated on one surface of the base film which is sufficiently smooth to prevent the occurrence of dropout and the other surface of the film being finely rugged to thereby impart good running property to the magnetic recording material.

Magnetic recording material

A method for heat bonding a polyester film directly with other film or shaped articles of polyester at a temperature below its melting point by using corona discharge treated polyester film, said polyester being predominantly alkylene terephthalate units and/or alkylene 2,6-naphthalate units and the film therefor.

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Sagamihara, Japan

Tomio Adachi