Patent US4407697A successfully refreshed from Google Patents.
US4407697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making electrical insulating paper and the product thereof
Assignee: Cooper Industries LLC
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Filing: 1982-04-05
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Granted: 1983-10-04
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Expires: 2002-04-05
Abstract
Abstract The invention relates to a method for improving the thermal stability and dielectric integrity of a cellulosic web product. The cellulosic web is impregnated with a nitrogen donor compound such that the web contains not less than 0.2% by weight of the compound and thereafter impregnated with an aqueous vegetable protein solution at a pH of not less than about 8.5.
Inventors
- 👤 Fred S. Sadler
- 👤 Paul F. Hettwer
- 👤 Vu H. Viet
- 👤 Clarance R. Acker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:53
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/48; H01B3/52; D; D21; D21H; D21H17/00; D21H17/20; D21H17/21; D21H17/22; D21H17/33; D21H17/46; D21H17/47; D21H17/49; D21H17/50; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31725; Y10T428/31779; Y10T428/31783; Y10T428/31971; Y10T428/31993
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
97 words
A method for improving the thermal stability and dielectric integrity of cellulosic material especially adaptable for use as electrical insulation comprising: (a) forming a continuous web of cellulosic material, (b) impregnating said web with a nitrogen-donor compound in an amount sufficient to provide said web with a nitrogen content of not less than 0.2% by weight, (c) drying said web to a moisture content not greater than 10% by weight, (d) thereafter impregnating said web with an aqueous solution of a vegetable protein having a pH of not less than about 8.5, and (e) drying said web.
Claim 2
Independent Claim
97 words
A method for improving the thermal stability and dielectric integrity of cellulosic material especially adaptable for use as electrical insulation comprising: (a) forming a continuous web of cellulosic material, (b) impregnating said web with a nitrogen-donor compound in an amount sufficient to provide said web with a nitrogen content of not less than 0.2% by weight, (c) drying said web to a moisture content not greater than 10% by weight, (d) thereafter impregnating said web with an aqueous solution of a vegetable protein having a pH of not less than about 8.5, and (e) drying said web.
Claim 3
Dependent Claim
12 words
The method according to claim 1 wherein said nitrogen-donor compound is dicyandiamide.
Claim 4
Dependent Claim
13 words
The method according to claim 1 wherein said vegetable protein is soybean protein.
Claim 5
Dependent Claim
19 words
The method according to claim 1 wherein said web has a density not greater than 0.9 gm/cm 3 .
Claim 6
Dependent Claim
18 words
The method according to claim 1 wherein said aqueous solution of vegetable protein has a pH of 9-10.
Claim 7
Independent Claim
101 words
A method for improving the thermal stability and dielectric integrity of cellulosic material especially adaptable for use as electrical insulation comprising: (a) forming a continuous web of cellulosic material having a density of not greater than 0.9 gm/cm 3 , (b) impregnating said web with dicyandiamide in an amount sufficient to provide said web with nitrogen content of not less than 0.2% by weight, (c) drying said web to a moisture content not greater than 10% by weight, (d) thereafter impregnating said web with an aqueous solution of soybean protein having a pH of about 9-10, and (e) drying said web.
Claim 8
Independent Claim
101 words
A method for improving the thermal stability and dielectric integrity of cellulosic material especially adaptable for use as electrical insulation comprising: (a) forming a continuous web of cellulosic material having a density of not greater than 0.9 gm/cm 3 , (b) impregnating said web with dicyandiamide in an amount sufficient to provide said web with nitrogen content of not less than 0.2% by weight, (c) drying said web to a moisture content not greater than 10% by weight, (d) thereafter impregnating said web with an aqueous solution of soybean protein having a pH of about 9-10, and (e) drying said web.
Claim 9
Dependent Claim
8 words
The product of the process of claim 1.
Claim 10
Dependent Claim
20 words
A cellulosic product according to claim 7 wherein said web has a density not greater than 0.9 gm/cm 3 .
Claim 11
Dependent Claim
8 words
The product of the process of claim 6.
Claim 12
Dependent Claim
92 words
In an electrical apparatus comprising in combination a container, an electrical conductor disposed in the container, cellulosic insulation applied to the conductor, and a liquid dielectric within the container surrounding the conductor and impregnating the cellulosic insulation, the improvement comprising incorporating first in the cellulosic insulation a nitrogen-donor compound in an amount sufficient to provide said cellulosic insulation with a nitrogen content of not less than about 0.2% by weight, and thereafter incorporating in said cellulosic insulation a vegetable protein from an aqueous solution having a pH of not less than 8.5.
Claim 13
Dependent Claim
92 words
In an electrical apparatus comprising in combination a container, an electrical conductor disposed in the container, cellulosic insulation applied to the conductor, and a liquid dielectric within the container surrounding the conductor and impregnating the cellulosic insulation, the improvement comprising incorporating first in the cellulosic insulation a nitrogen-donor compound in an amount sufficient to provide said cellulosic insulation with a nitrogen content of not less than about 0.2% by weight, and thereafter incorporating in said cellulosic insulation a vegetable protein from an aqueous solution having a pH of not less than 8.5.
Claim 14
Dependent Claim
21 words
The electrical apparatus according to claim 10 wherein said cellulosic insulation has a density not greater than 0.9 gm/cm 3 .
References Cited (Backward Citations)
US2339707A
Cited
US3119732A
Cited
US3135627A
Cited
US3224902A
Cited
US3166466A
Cited
US3211516A
Cited
US3328184A
Cited
US3736178A
Cited
US3903352A
Cited
US3931027A
Cited
US4196044A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |