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:
Sep. 11, 2012
Filed:
Jul. 14, 2011
Yufeng R. Liu, Woodbury, MN (US);
David T. Yust, Woodbury, MN (US);
Stephen A. Johnson, Woodbury, MN (US);
Kristopher J. Derks, Woodbury, MN (US);
Yufeng R. Liu, Woodbury, MN (US);
David T. Yust, Woodbury, MN (US);
Stephen A. Johnson, Woodbury, MN (US);
Kristopher J. Derks, Woodbury, MN (US);
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
The present invention relates to multilayer optical films and birefringent copolyester films. The birefringent copolyester optical layer or birefringent copolyester film comprises a major amount of naphthalate units, ethylene units, and a minor amount of branched or cyclic C4 to C10 alkyl units. Also described are certain copolyester polymeric materials further comprising subunits of a phthalate ionomer such as dimethyl sulfosodium isophthalate ionomer.