The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 01, 1990
Filed:
Aug. 08, 1988
Syoichi Tsuji, Aichi, JP;
Syoichi Ito, Aichi, JP;
Shuji Matsumura, Aichi, JP;
Hisatosi Suzuki, Aichi, JP;
Michiyasu Ito, Mie, JP;
Mitsui Toatsu Chemicals, Inc., Tokyo, JP;
Abstract
A process for producing a porous film having practically sufficient mechanical strengths, good flexibility, uniform fine pores and high moisture vapor permeability, and further an extremely thin porous film, which process comprises blending 30 to 80 parts by weight of an inorganic fine powder having a specific surface area of 15 m.sup.2 /g or less and an average particle size of 0.4 to 4 .mu.m with 20 to 70 parts by weight of a polyolefin resin, followed by melt-molding the resulting blend into a film and then stretching the film to 2 to 7 times the original length at least in the uniaxial direction.