Invention Grant
- Patent Title: Retarder
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Application No.: US16765400Application Date: 2018-11-19
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Publication No.: US11016231B2Publication Date: 2021-05-25
- Inventor: Stephen A. Johnson , Derek W. Patzman , Richard Y. Liu , Victor Ho , John F. Van Derlofske, III
- Applicant: 3M INNOVATIVE PROPERTIES COMPANY
- Applicant Address: US MN St. Paul
- Assignee: 3M INNOVATIVE PROPERTIES COMPANY
- Current Assignee: 3M INNOVATIVE PROPERTIES COMPANY
- Current Assignee Address: US MN St. Paul
- Agent Clifton F. Richardson
- International Application: PCT/US2018/061738 WO 20181119
- International Announcement: WO2019/108425 WO 20190606
- Main IPC: G02B5/30
- IPC: G02B5/30 ; C08L67/02

Abstract:
A retarder including first and second outer layers and a birefringent layer disposed between and in direct contact with the first and second outer layers is described. The birefringent layer may include a first polyester having greater than 45 mole percent naphthalate units and greater than 45 mole percent ethylene units. Each of the first and second outer layers includes a second polyester which may include 40 to 50 mole percent naphthalate units, at least 25 mole percent ethylene units, and 10 to 25 mole percent of branched or cyclic C4-C10 alkyl units. The retarder has a retardance in a range of 1 micrometer to 100 micrometers.
Public/Granted literature
- US20200333521A1 RETARDER Public/Granted day:2020-10-22
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