US4243708A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metallized textured surface polypropylene film
Assignee: General Electric Co
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Filing: 1979-04-16
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Granted: 1981-01-06
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Expires: 1999-04-16
Abstract
Abstract A metallized polypropylene film with improved surface impregnation properties for dielectric fluids is disclosed. The film has one predetermined textured surface and is characterized by a space factor of above about 5% and has an electrical conductive metallic coating on one surface.
Inventors
- 👤 John W. Eustance
- 👤 Stanley Y. Hobbs
- 👤 Emilie L. Carley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:21
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/14; H01G4/18; C; C23; C23C; C23C14/00; C23C14/06; C23C14/14; C23C14/20; H01G4/32; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/31; Y10T428/31504; Y10T428/31678; Y10T428/31692; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31938
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
82 words
A metallized film with improved surface impregnation properties for dielectric fluids which comprises a thin polypropylene film having one predetermined textured surface which is coextensively and uniformly covered by an overlapping pattern of fibroid irregularities comprising predominantly a stretched layer of Type I and Type II crystal structure, said film being characterized by a space factor of greater than about 5% and a haze measurement of greater than about 20%, and said film having an electrically conductive metallic coating on one surface.
Claim 2
Dependent Claim
82 words
A metallized film with improved surface impregnation properties for dielectric fluids which comprises a thin polypropylene film having one predetermined textured surface which is coextensively and uniformly covered by an overlapping pattern of fibroid irregularities comprising predominantly a stretched layer of Type I and Type II crystal structure, said film being characterized by a space factor of greater than about 5% and a haze measurement of greater than about 20%, and said film having an electrically conductive metallic coating on one surface.
Claim 3
Dependent Claim
48 words
The metallized film of claim 1, wherein said polypropylene film is produced by the steps of extruding polypropylene into a stalk, cooling the stalk to crystallize the polypropylene, passing the stalk through a heating zone and biaxially stretching the stalk through a heating zone into a thin film.
Claim 4
Dependent Claim
59 words
The metallized film of claim 2, wherein said stalk emanating from the extruder has a section primarily temperature controlled to the stalk velocity to cause extensive, continuous and uniform spherulite formation with a predominantly type III polypropylene crystal structure on the outer surface of the stalk, which upon subsequent inflation of the stalk caused the desired texture to occur.
Claim 5
Dependent Claim
13 words
The metallized film of claim 1, wherein said polypropylene consists of isotactic polypropylene.
Claim 6
Dependent Claim
53 words
The metallized film of claim 4, wherein one surface of the film is substantially smooth and flat and the opposite surface is a textured surface which is substantially uniform over the film to provide a space factor of above about 10% of the film having a thickness of between 12.5μ to 20 μ.
Claim 7
Dependent Claim
19 words
The metallized film of claim 4, wherein said polypropylene film has a textured surface as shown in FIG. 3.
Claim 8
Dependent Claim
19 words
The metallized film of claim 4, wherein said polypropylene film has a textured surface as shown in FIG. 4.
Claim 9
Dependent Claim
19 words
The metallized film of claim 4, wherein said polypropylene film has a textured surface as shown in FIG. 5.
Claim 10
Dependent Claim
35 words
The metallized film of claim 4, wherein the textured surface consists essentially of raised fibroids elevated 2 to 3 microns above the ordinary gage thickness of the film and coextensive over said one textured surface.
Claim 11
Dependent Claim
15 words
The metallized film of claim 1, wherein the metallic coating is on the textured surface.
Claim 12
Dependent Claim
19 words
The metallized film of claim 1, wherein the metallic coating is on the surface opposite to the textured surface.
Claim 13
Dependent Claim
12 words
The metallized film of claim 11, wherein the metallic coating is aluminum.
References Cited (Backward Citations)
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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) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |