US4384944A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carbon filled irradiation cross-linked polymeric insulation for electric cable
Assignee: Pirelli Cable Corp
•
Filing: 1981-09-03
•
Granted: 1983-05-24
•
Expires: 2001-09-03
Abstract
Abstract Insulation for an electric power cable, and a power cable including such insulation, the insulation having an improved dielectric strength and being irradiation cross-linked polymeric material having mixed therewith carbon black having a particle size in the range from about 200 to about 500 millimicrons, the carbon black content being about 10% to about 40% of the weight of the mixture of carbon black and the polymeric material. Also, the cable insulation may be layers of different density polyethylene, at least one of the layers being the described mixture of polyethylene and carbon black.
Inventors
- 👤 David A. Silver
- 👤 Rudolf G. Lukac
- 👤 Solomon Rubinstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:19
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/002; H01B3/004; H01B3/18; H01B3/30; H01B3/44; H01B3/46; H01B9/00; H01B9/02; H01B9/027; Y; Y10; Y10S; Y10S174/00; Y10S174/13; Y10S174/26; Y10S174/27; Y10S174/30; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294; Y10T428/2942; Y10T428/2947; Y10T428/296; Y10T428/30
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
180 words
An electrical insulator comprising a radiation cross-linked, polymeric material with carbon black distributed therein, the amount and particle size of the carbon black which is present in the polymeric material being such that the volume resistivity of said insulator is at least 1×10 10 ohm-cm., the carbon black having a particle size in the range from about 200 to about 500 millimicrons and being present in the polymeric material in an amount of about 10% to about 40% of the total weight of the polymeric material and the carbon black having a particle size in said range, said insulator being distinguished from other insulators comprising said radiation cross-linked, polymeric material with carbon black therein in particle sizes and amounts different from particle sizes in said range and in said amount not only by having a resistivity of at least 1×10 10 ohm-cm. but also having a greater dielectric strength and a reduction in at least one of the number and of the size of electron trees therein as compared to such other insulators having lesser amounts of said carbon black.
Claim 2
Dependent Claim
180 words
An electrical insulator comprising a radiation cross-linked, polymeric material with carbon black distributed therein, the amount and particle size of the carbon black which is present in the polymeric material being such that the volume resistivity of said insulator is at least 1×10 10 ohm-cm., the carbon black having a particle size in the range from about 200 to about 500 millimicrons and being present in the polymeric material in an amount of about 10% to about 40% of the total weight of the polymeric material and the carbon black having a particle size in said range, said insulator being distinguished from other insulators comprising said radiation cross-linked, polymeric material with carbon black therein in particle sizes and amounts different from particle sizes in said range and in said amount not only by having a resistivity of at least 1×10 10 ohm-cm. but also having a greater dielectric strength and a reduction in at least one of the number and of the size of electron trees therein as compared to such other insulators having lesser amounts of said carbon black.
Claim 3
Dependent Claim
40 words
An electrical insulator as set forth in claim 1 wherein said volume resistivity of said insulator is at least 1×10 15 ohm-cm. and said carbon black having a particle size in said range is present in an amount from 20-30%.
Claim 4
Dependent Claim
32 words
An electrical insulator as set forth in claim 2 wherein substantially all the carbon black which is present in said polymeric material has a particle size in the range from 200-500 millimicrons.
Claim 5
Dependent Claim
38 words
An electrical insulator as set forth in claim 1, 2 or 3 wherein said polymeric material is selected from the group consisting of polyethylene, polyvinyl chloride, silicone rubber, styrene butadiene rubber, ethylene copolymers, ethylene terpolymers, and mixtures thereof.
References Cited (Backward Citations)
US3133894A
Cited
US3325325A
Cited
US3096210A
Cited
US3529340A
Cited
US3725230A
Cited
US3793476A
Cited
US3991397A
Cited
US3925597A
Cited
US4150193A
Cited
US4303574A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-23 | 1986-11-22 | 1987-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-23 | 1990-11-22 | 1991-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-23 | 1994-11-22 | 1995-05-24 | $7700.00 | Window Closed / Lapsed |