US4687295A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fiber having polymethacrylate core and fluoro-copolymer cladding
Assignee: Central Glass Co Ltd
•
Filing: 1985-07-11
•
Granted: 1987-08-18
•
Expires: 2005-07-11
Abstract
Abstract The invention relates to an optical fiber of the step-index type in which the core material is poly(methyl methacrylate) or a copolymer of methyl methacrylate with another methacrylate or an acrylate. A copolymer of vinylidene fluoride with hexafluoroacetone is employed as the cladding material which makes good adhesion to the polymethacrylate core. When the amount of hexafluoroacetone is 4-20 mole %, the copolymer is low in crystallinity, high in transparency, appropriately low in refrax index and higher than 100° C. in softening temperature, and can be extruded under the conditions suited to extrusion of poly(methyl methacrylate).
Inventors
- 👤 Toshio Koishi
- 👤 Isao Tanaka
- 👤 Takashi Yasumura
- 👤 Yukitoshi Nishikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:20
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/02033
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
45 words
An optical fiber comprising: a solid cylindrical core formed of a polymer at least a major constituent of which is methyl methacrylate; and a cladding layer which is in close contact with the core and is formed of a copolymer of vinylidene fluoride with hexafluoroacetone.
Claim 2
Dependent Claim
45 words
An optical fiber comprising: a solid cylindrical core formed of a polymer at least a major constituent of which is methyl methacrylate; and a cladding layer which is in close contact with the core and is formed of a copolymer of vinylidene fluoride with hexafluoroacetone.
Claim 3
Dependent Claim
27 words
An optical fiber according to claim 1, wherein the molar ratio of vinylidene fluoride to hexafluoroacetone in said copolymer is in the range from 96:4 to 80:20.
Claim 4
Dependent Claim
19 words
An optical fiber according to claim 2, wherein said molar ratio is in the range from 96:4 to 88:12.
Claim 5
Dependent Claim
20 words
An optical fiber according to claim 1, wherein said polymer as the core material is a homopolymer of methyl methacrylate.
Claim 6
Dependent Claim
50 words
An optical fiber according to claim 1, wherein said polymer as the core material is a copolymer of methyl methacrylate with a methacrylate or acrylate selected from the group consisting of ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, 2-ethylexyl methacrylate, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate.
Claim 7
Dependent Claim
23 words
An optical fiber according to claim 5, wherein methyl methacrylate occupies at least 70 mole % of said copolymer as the core material.
References Cited (Backward Citations)
GB1037498A
Cited
US3993834A
Cited
US4264129A
Cited
US4381269A
Cited
US4505543A
Cited
US4564263A
Cited
US4544235A
Cited
US4542957A
Cited
US4566755A
Cited
US4552431A
Cited
US4593974A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-17 | 1991-02-16 | 1991-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-17 | 1995-02-16 | 1995-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-17 | 1999-02-16 | 1999-08-18 | $7700.00 | Window Closed / Lapsed |