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. 03, 2007
Filed:
Feb. 10, 2003
Tetsuo Yoshida, Sagamihara, JP;
Tetsuo Ichihashi, Sagamihara, JP;
Tetsuo Yoshida, Sagamihara, JP;
Tetsuo Ichihashi, Sagamihara, JP;
Teijin Limited, Osaka, JP;
Abstract
The present invention is a multilayer polyester film comprising a layer A and a layer B which are laminated alternately, the layer A constituting the outermost layer on both sides of the film, wherein (1) the layer A comprises a polyester A, and the layer B comprises a polyester B, (2) the melting point of the polyester A is higher than the melting point of the polyester B by at least 15° C., (3) the layer A is a layer having an oriented structure, and the layer B is a layer having a substantially unoriented structure, (4) the ratio (a/b) of the total thickness (a) of the layer A to the total thickness (b) of the layer B is 0.01 to 3, and (5) the in-plane tensile strength of the multilayer polyester film is 50 MPa or lower at a maximum, and the difference between its maximum value and minimum value is 20 MPa or smaller; and a method for producing the multilayer polyester film. According to the present invention, there is provided a film having excellent isotropy of in-plane tensile strength, excellent transparency, a low degree of thickness unevenness and excellent moldability.