Patent US4731495A successfully refreshed from Google Patents.
US4731495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical insulating oils
Assignee: Idemitsu Kosan Co Ltd
•
Filing: 1986-05-19
•
Granted: 1988-03-15
•
Expires: 2006-05-19
Abstract
Abstract This invention relates to an electrical insulating oil consisting essentially of a oil having a boiling point of not less than 150 DEG C., a viscosity of 2 to 500 centistokes (at 40 DEG C.), a pour point of not more than -35 DEG C., a sulfur content of from more than 5 ppm to not more than 1,000 ppm and an aromatic hydrocarbon content (% CA) of more than 5%.
Inventors
- 👤 Takao Katayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:13
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
65 words
An electrical insulating oil consisting essentially of an oil having a boiling point of not less than 150° C., a viscosity of 2 to 500 centistokes (at 40° C.), a pour point of not more than -35° C., a sulfur content of from more than 5 ppm to not more than 800 ppm and an aromatic hydrocarbon content (%C A ) of more than 5%.
Claim 2
Dependent Claim
65 words
An electrical insulating oil consisting essentially of an oil having a boiling point of not less than 150° C., a viscosity of 2 to 500 centistokes (at 40° C.), a pour point of not more than -35° C., a sulfur content of from more than 5 ppm to not more than 800 ppm and an aromatic hydrocarbon content (%C A ) of more than 5%.
Claim 3
Dependent Claim
14 words
The oil as claimed in claim 1, wherein the oil is a mineral oil.
Claim 4
Dependent Claim
102 words
The oil as claimed in claim 1, wherein the oil is composed of 99.5 to 50% by weight of a mineral oil having a boiling point of not less than 150° C., a viscosity of 2 to 500 centistokes (at 40° C.), a pour point of not more than -35° C., a sulfur content of not more than 5 ppm and an aromatic hydrocarbon content (%C A ) of not more than 5%, and 0.5 to 50% by weight of at least one oil selected from the group consisting of a mineral oil and a synthetic oil, each containing an aromatic hydrocarbon.
Claim 5
Dependent Claim
25 words
The oil as claimed in claim 1, wherein the oil is a mineral oil having a boiling point of from 200° C. to 600° C.
Claim 6
Dependent Claim
25 words
The oil as claimed in claim 1, wherein the oil is a mineral oil having a viscosity of 3 to 40 centistokes (at 40° C.).
Claim 7
Dependent Claim
17 words
The oil as claimed in claim 1, wherein the oil is a not more than -40° C.
Claim 8
Dependent Claim
25 words
The oil as claimed in claim 1, wherein the oil is a mineral oil having a sulfur content of from 6 ppm to 800 ppm.
Claim 9
Dependent Claim
27 words
The oil as claimed in claim 1, wherein the oil is a mineral oil having an aromatic hydrocarbon content (%C A ) of from 6% to 30%.
Claim 10
Dependent Claim
67 words
The oil as claimed in claim 1, wherein the oil is a mineral oil having a boiling point of from 200° C. to 600° C., a viscosity of 3 to 40 centistokes (at 40° C.), a pour point of not more than -40° C., a sulfur content of from 6 ppm to 800 ppm and an aromatic hydrocarbon content (%C A ) of from 6% to 30%.
Claim 11
Dependent Claim
29 words
The oil as claimed in claim 1, wherein the oil is a mineral oil which is prepared by subjecting a distilled oil to two or three sequential hydrogenation treatments.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-15 | 1991-09-14 | 1992-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-15 | 1995-09-14 | 1996-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-15 | 1999-09-14 | 2000-03-15 | $7700.00 | Window Closed / Lapsed |