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:
Jul. 16, 2002
Filed:
Jun. 04, 1998
Tetsuya Hasegawa, Sagamihara, JP;
Hirofumi Murooka, Sagamihara, JP;
Koji Kubo, Sagamihara, JP;
Tetsuo Yoshida, Sagamihara, JP;
Teijin Limited, Osaka, JP;
Abstract
The invented film comprises a layer A composed of a copolyester A, a layer B composed of a copolyester B, and a layer C composed of copolyester C. Layer A is laminated to one side of the layer B. Layer C is laminated to the other side of Layer B. Copolyester A contains 0-15 wt % of rutile titanium oxide (average particle diameter 0.1-0.5 &mgr;m). Copolyester B contains 10-50 wt % of the rutile titanium oxide. Copolyester C contains 0-15 wt % of the rutile titanium oxide. Each of Copolyester A, B, and C has a melting point of 210-245° C. The intrinsic viscosity (&eegr; ) of the polymer part of copolyester A, the intrinsic viscosity (&eegr; ) of the polymer part of copolyester B, and the intrinsic viscosity (&eegr; ) of the polymer part of copolyester C satisfy the following relationship. 0.46≦&eegr; ≦0.66, |&eegr; -&eegr; |<0.15, |&eegr; -&eegr; |<0.15, and |&eegr; -&eegr; |<0.15. The ratio of the apparent density (&rgr;) to the calculated density (&rgr; ) of the entire laminated film satisfies the following formula, 0.75≦&rgr;/&rgr; ≦1.00. The calculated density (&rgr; ) is calculated with density of the polymer part of each copolyester, density of rutile titanium oxide, thickness of each layer, concentration of rutile titanium oxide in each copolyester, and number of copolyester layers.