Patent US4500694A successfully refreshed from Google Patents.
US4500694A
Expired / Lapsed
US
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Optical materials
Assignee: Daikin Industries Ltd
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Filing: 1983-05-03
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Granted: 1985-02-19
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Expires: 2003-05-03
Abstract
Abstract An optical material comprising a thermal resisting fluoroalkylmethacrylate copolymer which essentially consists of (a) fluorine-containing methacrylate monomer unit of the formula <IMAGE> wherein Rf1 represents a fluoroalkyl group having 1 to 3 carbon atoms and (b) a fluorine-containing acrylate monomer unit of the formula <IMAGE> wherein R1 and R2 are the same or different and represents a hydrogen atom or a lower alkyl group and Rf2 represents a fluoroalkyl group having 1 to 3 carbon atoms.
Inventors
- 👤 Akira Ohmori
- 👤 Nobuyuki Tomihashi
- 👤 Takahiro Kitahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:07
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; G02B1/045; G02B1/048; B; B29; B29C; B29C48/00; B29C48/03; B29C48/05; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2964
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
98 words
An optical material comprising a thermal resisting fluoroalkylmethacrylate copolymer which essentially consists of: (a) about 70 to about 99 mol % of fluorine-containing methacrylate monomer unit of the formula ##STR7## wherein R f 1 represents a fluoroalkyl group having 1 to 3 carbon atoms and (b) about 1 to about 30 mol % of a fluorine-containing acrylate monomer unit of the formula ##STR8## wherein R 1 and R 2 are the same or different and represents a hydrogen atom or a lower alkyl group and R f 2 represents a fluoroalkyl group having 1 to 3 carbon atoms.
Claim 2
Dependent Claim
98 words
An optical material comprising a thermal resisting fluoroalkylmethacrylate copolymer which essentially consists of: (a) about 70 to about 99 mol % of fluorine-containing methacrylate monomer unit of the formula ##STR7## wherein R f 1 represents a fluoroalkyl group having 1 to 3 carbon atoms and (b) about 1 to about 30 mol % of a fluorine-containing acrylate monomer unit of the formula ##STR8## wherein R 1 and R 2 are the same or different and represents a hydrogen atom or a lower alkyl group and R f 2 represents a fluoroalkyl group having 1 to 3 carbon atoms.
Claim 3
Dependent Claim
18 words
An optical material according to claim 1 wherein R f 1 is trifluoromethyl-, pentafluoroethyl-, 1,1,2,2-tetrafluoroethyl or 1,1,2,3,3,3-hexafluoropropyl group.
Claim 4
Dependent Claim
18 words
An optical material according to claim 1 wherein R f 2 is trifluoromethyl-, pentafluoroethyl-, 1,1,2,2-tetrafluoroethyl- or 1,1,2,3,3,3-hexafluoropropyl group.
Claim 5
Dependent Claim
37 words
An optical material according to claim 1 wherein said fluoroalkylmethacrylate copolymer further contains a methacrylate monomer having no fluorine in an amount up to 25% by weight based on the total amount of monomers to be copolymerized.
Claim 6
Dependent Claim
15 words
An optical material according to claim 4 wherein said methacrylate having no fluorine is methylmethacrylate.
References Cited (Backward Citations)
US3993834A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-19 | 1988-08-20 | 1989-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-19 | 1992-08-20 | 1993-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-19 | 1996-08-20 | 1997-02-19 | $7700.00 | Window Closed / Lapsed |