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:
Jun. 08, 1982
Filed:
Jun. 24, 1980
Takanori Urasaki, Hino, JP;
Yasuji Hirabayashi, Hachioji, JP;
Makoto Ogasawara, Hino, JP;
Hiroo Inata, Hino, JP;
Teitin Limited, Osaka, JP;
Abstract
A melt-molded film of a wholly aromatic polyester, said film having in its plane two perpendicularly crossing directions in each of which the Young's modulus and strength of the film at 25.degree. C. are at least about 200 kg/mm.sup.2 and at least about 5 kg/mm.sup.2 respectively, the product of the Young's moduli of the film in the two directions being at least 8.times.10.sup.4 (kg/mm.sup.2).sup.2, and said wholly aromatic polyester being substantially linear, having a melt viscosity at about its melting point of at least about 10000 poises, and being composed substantially of recurring units derived from p-hydroxybenzoic acid, recurring units derived from a m- or p-oriented aromatic dicarboxylic acid and recurring units derived from a m- or p-oriented aromatic dihydroxy compound, the proportion of said recurring units derived from p-hydroxybenzoic acid being about 30 to about 70 mole % based on the entire recurring units. This invention provides also a process for producing said film which comprises heating aforesaid wholly aromatic polyester to a temperature above a point at which the polyester is extrusion-moldable and extruding the heated polyester through a slit; and either (i) orienting the extruded film in the extruding direction or machine direction and a direction perpendicular thereto while the heated aromatic polyester resides in said slit or after it has left the slit but before it is cooled to the glass transition temperature of the polyester, of (ii) orienting the extruded film substantially only in the extruding direction or machine direction while the polyester heated at said temperature resides in the slit, or after it has left the slit but before it is cooled to the glass transition temperature of the polyester, and then re-heating the film to a temperature higher than the glass transition temperature of the polyester, and orienting the film in a direction perpendicular to the machine direction.