Diafoil Company, Ltd.

Daifoil Company, Limited

Yoshinori Sato

Narihiro Masuda

Satoshi Otonari

Seiji Sakamoto

Tomoyuki Kotani

Shigeo Utsumi

Yujiro Fukuda

Kazuyuki Akatsu

Disclosed herein is a magnetic card comprising a monoaxially or biaxially stretched minute-cellular polyester film which has an apparent density of 0.4 to 1.3 g/cm.sup.3 and an opacifying power of 0.2 or more and a magnetic layer applied on at least one surface of said film. By using the polyester film containing small air bubbles as the base material of the magnetic card, flexibility, flatness and punching property, which were insufficient in a magnetic card using a conventional polyester film, are improved.

Magnetic card

Minute-cellular polyester film

A film is disclosed, which comprises an at least uniaxially stretched finely cellulated polyester film of a high surface roughness having an apparent specific gravity in the range of 0.4 to 1.3 and an opacifying power of not less than 0.2, and a coating applied to either or both of the opposite surfaces of the polyester film. The coating applied to the minute-cellular polyester film serves the purpose of improving the adhesive property of the polyester film.

Minute-cellular polyester film provided with coating

Disclosed herein is a process for producing a polyphenylene sulfide film, which comprises melt-molding polyphenylene sulfides in a sheet-like form from a die, casting the thus obtained sheet-like form onto a chilled drum on which an adhering liquid has been applied, while closely contacting the sheet-like form with the chilled drum surface by an electrostatic pinning method.

Process for producing polyphenylene sulfide film

Disclosed herein is a biaxially oriented polyethylene naphthalate film having a center line average roughness [Ra(.mu.m)] and a film thickness [T(.mu.m)] which satisfy the following formula: ##EQU1## produced by the electrostatic cooling method from polymethylene naphthalate having a resistivity of 1.times.10.sup.7 to 5.times.10.sup.8 .OMEGA..cm as measured in the molten state.

Polyethylene naphthalate film

Disclosed herein is an electrical insulating material which comprises biaxially oriented polyethylene naphthalate film having a center line average roughness of 0.008 to 0.08 .mu.m as measured on the surface thereof and a resistivity of 5.times.10.sup.7 to 5.times.10.sup.10 .OMEGA..multidot.cm as measured in the molten state.

Growing community of inventors

Machida, Japan

Yoshinori Sato