US3617438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric insulating paper and its production process
Assignee: Tomoegawa Paper Manufacturing Co Ltd
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Filing: 1970-02-12
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Granted: 1971-11-02
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Expires: 1990-02-12
Abstract
Abstract A process for the production of an electric insulating paper and the insulating paper thus produced, having superior characteristics such as a low dielectric constant, a low dielectric loss tangent, and a high dielectric strength, is disclosed. The process comprises the steps of preparing a graftcellulose solution, or a mixed solution or suspension consisting of a synthetic polymer mixed into a cellulose solution or a graft-cellulose solution, solidifying the solution, mixed solution, or suspension into a regenerating substance such as air or a precipitant, forming the regenerated substance thus solidified into a pulplike substance adapted to be fabricated into a paper, and forming the pulplike substance only or the pulplike substance mixed with the ordinary beaten pulp into an insulating paper.
Inventors
- 👤 Osakazu Nakao
- 👤 Juichi Hirose
- 👤 Toshio Nakamura
- 👤 Hiroyuki Yamamoto
- 👤 Shinji Matsuda
- 👤 Hidetaro Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:14
CPC Classifications
D; D21; D21H; D21H11/00; D21H11/02; D21H11/04; D21H11/16; D21H11/20; D21H5/00; D21H5/12; D21H5/14; D21H5/141; D21H5/143; H; H01; H01B; H01B3/00; H01B3/18; H01B3/48; H01B3/485
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
15 words
The process of claim 1 wherein said liquid mixture of step (1) is a solution.
Claim 2
Dependent Claim
15 words
The process of claim 1 wherein said liquid mixture of step (1) is a dispersion.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said medium of step (2) is air.
Claim 4
Dependent Claim
15 words
The process of claim 1 wherein said medium of step (2) is a liquid precipitant.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein said configuration of step (3) is pulp.
Claim 6
Dependent Claim
22 words
The process of claim 1 wherein said polymer cellulose of step (4) is blended with additional beaten pulp containing no synthetic polymer.
Claim 7
Dependent Claim
15 words
The process of claim 7 wherein said configuration of step (3) is a granular configuration.
Claim 8
Dependent Claim
121 words
The method of claim 1 wherein the synthetic polymer cellulose liquid mixture is prepared using a solvent system selected from the group consisting of (a) a system consisting of an organic solvent, sulfurous acid anhydride, and an amine, selected from the group consisting of aliphatic primary amines, aliphatic secondary amines, aliphatic tertiary amines and alicyclic secondary amines, (b) a system consisting of an organic solvent, and nitrogen dioxide, (c) a system consisting of an organic solvent and nitrosyl chloride, (d) a system consisting of an organic solvent, and chloral anhydride, and (e) a system consisting of liquefied sulfurous acid and an amine selected from the group consisting of aliphatic primary amines, aliphatic secondary amines, aliphatic tertiary amines and alicyclic secondary amines.
Claim 9
Dependent Claim
46 words
The method of claim 1 wherein said synthetic polymer is selected from a group consisting of a polycarbonate, a polyphenylenoxide, a polysulfone, a polystyrene, a cross-linked polyethylene, a polytetrafluoroethylene, a polytrifluorochloroethylene, a polypropylene, a polyacetal, a poly-4-methyl pentane-1, a polyvinylcarbazole, a polyester, and a polyfluoroethylenepropylene copolymer.
Claim 10
Dependent Claim
27 words
The method of claim 1 wherein said graft cellulose is selected from the group consisting of a styrene grafted cellulose, a silicone-grafted cellulose, and a vinyl-grafted cellulose.
Claim 11
Dependent Claim
110 words
An electric insulating paper having superior electrical characteristics, produced by the steps (1) preparing a synthetic polymer cellulose liquid mixture by mixing a synthetic polymer with a member selected from the group consisting of a cellulose solution and a grafted cellulose solution; (2) extruding the thus prepared liquid mixture into a medium for regenerating the polymer cellulose as a solid; (3) forming the regenerated polymer cellulose into a configuration adapted to be processed into a paper; and (4) processing the thus formed polymer cellulose into a paper of Sheet form; said paper in a sheet form containing a synthetic polymer in a range of from 20 to 80 weight percent.
Claim 12
Dependent Claim
47 words
The electric insulating paper of claim 12 wherein said synthetic polymer is selected from the group consisting of a polycarbonate, a polyphenyleneoxide, a polysulfone, a polystyrene, a cross-linked polyethylene, a polytetrafluoroethylene, a polytrifluorochloroethylene, a polypropylene, a polyacetal, a poly-4-methylpentane-1, a polyvinylcarbazole, a polyester, and a polyfluoroethylenepropylene copolymer.
Claim 13
Dependent Claim
27 words
The electric insulating paper of claim 12 wherein said grafted cellulose is selected from the group consisting of a styrene-grafted cellulose, silicone-grafted cellulose, and a vinyl-grafted cellulose.
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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) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |