Patent US4626618A successfully refreshed from Google Patents.
US4626618A
Expired / Lapsed
US
⏱️ 0.0 years remaining
DC electric power cable
Assignee: Fujikura Ltd
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Filing: 1985-05-03
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Granted: 1986-12-02
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Expires: 2005-05-03
Abstract
Abstract A DC power cable includes a conductor and an insulation of a thermoplastic resin formed around the conductor. The insulation contains carbon black in an amount of about 0.2 to about 5% of the total weight of the thermoplastic resin and the carbon black, and the ratio of mineral oil absorption (cc/100 g) to specific surface (m 2 /g) in the carbon black is not less than 0.7. The carbon black has the hydrogen content of not more than 0.6% by weight. The specific surface is measured by BET equation. The carbon black has a particle size of 10 to 100 nm.
Inventors
- 👤 Michio Takaoka
- 👤 Tsuneaki Motai
- 👤 Motoyuki Ono
- 👤 Shotaro Yoshida
- 👤 Toshio Niwa
- 👤 Toru Takahashi
- 👤 Keiichiro Kataoka
- 👤 Hiroshi Yamanouchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:37
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/42; C; C08; C08K; C08K3/00; C08K3/02; C08K3/04; H01B3/44; H01B3/441; H01B9/00; H01B9/02; H01B9/027; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2918; Y10T428/292
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
69 words
A DC power cable comprising a conductor and an insulation of a thermoplastic resin formed around said conductor, said insulation containing about 0.2 to about 5% by weight of carbon black, the ratio of mineral oil absorption (cc/100 g) to specific surface (m 2 /g) in said carbon black being not less than 0.7, and said carbon black having the hydrogen content of not more than 0.6% by weight.
Claim 2
Dependent Claim
69 words
A DC power cable comprising a conductor and an insulation of a thermoplastic resin formed around said conductor, said insulation containing about 0.2 to about 5% by weight of carbon black, the ratio of mineral oil absorption (cc/100 g) to specific surface (m 2 /g) in said carbon black being not less than 0.7, and said carbon black having the hydrogen content of not more than 0.6% by weight.
Claim 3
Dependent Claim
22 words
A DC power cable according to claim 1, in which said carbon black has a particle size of 10 to 100 nm.
Claim 4
Dependent Claim
50 words
A DC power cable according to claim 1, in which said thermoplastic resin of which said insulation layer is made is selected from the group consisting of polyethylene such as low-density polyethylene and high-density polyethylene, polypropylene, ethylene vinyl acetate copolymer (EVA), ethylene ethyl acrylate copolymer (EEA), ethylene propylene rubber (EPR).
Claim 5
Dependent Claim
18 words
A DC power cable according to claim 1, in which said thermoplastic resin is in the crosslinked form.
Claim 6
Dependent Claim
48 words
A DC power cable according to claim 1, in which an inner semi-conductive layer is formed on the conductor, said insulation layer being formed on the inner semi-conductive layer, an outer semi-conductive layer being formed on the insulation layer, and a sheath formed on the outer semi-conductive layer.
Claim 7
Dependent Claim
22 words
A DC power cable according to claim 1, in which said carbon black contains not less than 97% by weight of carbon.
Claim 8
Dependent Claim
30 words
A DC power cable according to claim 1, in which said carbon black is a furnace black, said ratio of oil absorption to specific surface being not more than 3.5.
Claim 9
Dependent Claim
46 words
A DC power cable according to claim 1, in which said carbon black is selected from the group consisting of SAF carbon, ISAF carbon, I-ISAF carbon, CF carbon, SCF carbon and HAF carbon, said ratio of oil absorption to specific surface being not more than 1.5.
Claim 10
Dependent Claim
15 words
A DC power cable according to claim 8, in which said thermoplastic resin is polyethylene.
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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) | 1989-12-01 | 1990-06-02 | 1990-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-01 | 1994-06-02 | 1994-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-01 | 1998-06-02 | 1998-12-02 | $7700.00 | Window Closed / Lapsed |