US4832443A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fibre optic cable having a layer of a polyethylene composition and process of making same
Assignee: BP Chemicals Ltd
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Filing: 1988-03-28
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Granted: 1989-05-23
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Expires: 2008-03-28
Abstract
Abstract A fibre optic cable suitable for use as a long distance submarine telecommunications cable comprises a tubular electrical conductor (8) within which are tension members and a core containing optical fibres (1 to 6), the tubular electrical conductor (8) being coated with a polyethylene composition comprising a linear medium density polyethylene which is a copolymer of ethylene and a C 4 to C 10 alpha-olefin which copolymer has a density of from 0.928 to 0.940 g/cm 3 , a Melt Index of at least 2.5 dg /min, a melting point of from 118° to 127° C. and a weight average molecular weight of from 80,000 to 100,000.
Inventors
- 👤 Robert Cameron
- 👤 Denis J. McMahon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:59
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/44; G02B6/4401; G02B6/4415; G02B6/4416; G02B6/4427; G02B6/4429; G02B6/443; H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/44; H01B3/441
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
78 words
A fibre optic cable having a layer of a polyethylene composition characterised in that the polyethylene composition comprises a linear medium density polyethylene which is a copolymer of ethylene and a C 4 to C 10 alpha-olefin which copolymer has a density of from 0.928 to 0.940 g/cm 3 , a Melt Index of at least 2.5 dg/min, a melting point of from 118° to 127° C. and a weight average molecular weight of from 80,000 to 100,000.
Claim 2
Dependent Claim
78 words
A fibre optic cable having a layer of a polyethylene composition characterised in that the polyethylene composition comprises a linear medium density polyethylene which is a copolymer of ethylene and a C 4 to C 10 alpha-olefin which copolymer has a density of from 0.928 to 0.940 g/cm 3 , a Melt Index of at least 2.5 dg/min, a melting point of from 118° to 127° C. and a weight average molecular weight of from 80,000 to 100,000.
Claim 3
Dependent Claim
17 words
A fibre optic cable as claimed in claim 1 in which the polyethylene composition contains an antioxidant.
Claim 4
Dependent Claim
15 words
A fibre optic cable as claimed in claim 2 in which the antioxidant is 1,3,5-timethyl-2,4,6-tris[3,5-tert-butyl-4-hydroxybenzyl]benzene.
Claim 5
Dependent Claim
35 words
A fibre optic cable as claimed in claim 2 in which the amount of antioxidant is sufficient to provide a Differential Scanning Calorimeter (DSC) oxidative induction time at 200° C. of more than 40 mins.
Claim 6
Dependent Claim
30 words
A fibre optic cable as claimed in claim 2 in which the polyethylene composition containing the antioxidant has a stress crack resistance of at least F o at 48 hours.
Claim 7
Dependent Claim
30 words
A fibre optic cable as claimed in claims 2 in which the polyethylene composition containing antioxidant used to insulate the cable has a brittleness temperature of less than -50° C.
Claim 8
Dependent Claim
104 words
A fibre optic cable, suitable for use as submarine telecommunications cable, comprising a tubular electrical conductor within which are tension members and a core containing optical fibres, the tubular electrical conductor being coated with a polyethylene composition characterised in that the polyethylene composition comprises a linear medium density polyethylene which is a copolymer of ethylene and a C 4 to C 10 alpha-olefin which copolymer has a density of from 0.928 to 0.940 g/cm 3 , a Melt Index of at least 2.5 dg/min, a melting point of from 118° to 127° C. and a weight average molecular weight of from 80,000 to 100,000.
Claim 9
Dependent Claim
104 words
A fibre optic cable, suitable for use as submarine telecommunications cable, comprising a tubular electrical conductor within which are tension members and a core containing optical fibres, the tubular electrical conductor being coated with a polyethylene composition characterised in that the polyethylene composition comprises a linear medium density polyethylene which is a copolymer of ethylene and a C 4 to C 10 alpha-olefin which copolymer has a density of from 0.928 to 0.940 g/cm 3 , a Melt Index of at least 2.5 dg/min, a melting point of from 118° to 127° C. and a weight average molecular weight of from 80,000 to 100,000.
Claim 10
Dependent Claim
55 words
A fibre optic cable as claimed in claim 1 or claim 7 in which the polyethylene composition comprises (A) a linear ethylene-butene copolymer having a density of 0.930 g/cm 3 , a melt index of 3.75 dg/min, a melting point of about 126° C. and a weight average molecular weight of 90,000 and (B) 1,3,5-trimethyl-2,4,6-tris[3,5-tert.-butyl-4-hydroxybenzl]benzene.
Claim 11
Dependent Claim
86 words
A process for manufacturing a fibre optic cable comprising extruding about a core containing optical fibres a polyolefin composition characterised in that the polyethylene composition comprises a linear medium density polyethylene which is a copolymer of ethylene and a C 4 to C 10 alpha-olefin which copolymer has a density of from 0.928 to 0.940 g/cm 3 , a Melt Index of at least 2.5 dg/min, a melting point of from 118° to 127° C. and a weight average molecular weight of from 80,000 to 100,000.
Claim 12
Dependent Claim
86 words
A process for manufacturing a fibre optic cable comprising extruding about a core containing optical fibres a polyolefin composition characterised in that the polyethylene composition comprises a linear medium density polyethylene which is a copolymer of ethylene and a C 4 to C 10 alpha-olefin which copolymer has a density of from 0.928 to 0.940 g/cm 3 , a Melt Index of at least 2.5 dg/min, a melting point of from 118° to 127° C. and a weight average molecular weight of from 80,000 to 100,000.
Claim 13
Dependent Claim
29 words
A process as claimed in claim 9 in which the core containing optical fibres is within a tubular electrical conductor and the polyolefin composition is extruded over the conductor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |