US4692837A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coextruded, biaxially oriented, multi-layer and capacitor made therefrom
Assignee: Hoechst AG
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Filing: 1986-11-12
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Granted: 1987-09-08
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Expires: 2006-11-12
Abstract
Abstract The multi-layer film comprises a propylene polymer base layer having a stabilizer content of up to 0.2% by weight and outer layers, also composed of propylene polymer, having a stabilizer content of at least 0.3% by weight. The outer layers contain 3 to 10 times the amount of stabilizer present in the base layer, as a result of which the initial value of the dielectric loss factor tan of the multi-layer film is kept low, and the loss factor exhibits only a slight increase with time.
Inventors
- 👤 Guenther Crass
- 👤 Lothar Bothe
- 👤 Gunter Schloegl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:11
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/18; B32B27/32; H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/44; H01B3/441; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/20; B32B2307/00; B32B2307/20; B32B2307/204; B32B2307/50; B32B2307/514; B32B2307/518; B32B2323/00; B32B2323/10; B32B2457/00; B32B2457/16
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
88 words
A coextruded, biaxially oriented, multi-layer film comprising: a base layer and two outer layers on either side of said base layer, said base layer and said two outer layers including a high-purity electrical insulation plastic film material, having a maximum residual ash content of less than about 100 ppm, and a stabilizer, wherein the ratio of the amount of said stabilizer present in said two outer layers and the amount of said stabilizer present in said base layer lies within the range from about 3:1 to about 10:1.
Claim 2
Dependent Claim
88 words
A coextruded, biaxially oriented, multi-layer film comprising: a base layer and two outer layers on either side of said base layer, said base layer and said two outer layers including a high-purity electrical insulation plastic film material, having a maximum residual ash content of less than about 100 ppm, and a stabilizer, wherein the ratio of the amount of said stabilizer present in said two outer layers and the amount of said stabilizer present in said base layer lies within the range from about 3:1 to about 10:1.
Claim 3
Dependent Claim
18 words
A film as claimed in claim 1, wherein said electrical insulation plastic film material comprises a propylene polymer.
Claim 4
Dependent Claim
23 words
A film as claimed in claim 2, wherein said propylene polymer has a maximum residual ash content of less than about 50 ppm.
Claim 5
Dependent Claim
30 words
A film as claimed in claim 1, wherein said stabilizer comprises a sterically hindered phenol, a thioether, a secondary aromatic amine, a phosphite and a phosphonite or a mixture thereof.
Claim 6
Dependent Claim
25 words
A film as claimed in claim 4, wherein said stabilizer comprises a sterically hindered phenolic stabilizer having a molecular weight greater than about 300 g/mol.
Claim 7
Dependent Claim
17 words
A film as claimed in claim 5, wherein said molecular weight is greater than about 1,000 g/mol.
Claim 8
Dependent Claim
45 words
A film as claimed in claim 4, wherein said stabilizer comprises a sterically hinded phenolic stabilizer in combination with a stabilizer comprising a phosphite or a phosphonite, and wherein the ratio of said combination lies within the range of from about 1:5 to about 5:1.
Claim 9
Dependent Claim
21 words
A film as claimed in claim 7, wherein said combination ratio is within the range from about 1:3 to about 3:1.
Claim 10
Dependent Claim
32 words
A film as claimed in claim 1, wherein said base layer comprises said stabilizer in an amount of up to about 0.2% by weight, calculated on total weight of said base layer.
Claim 11
Dependent Claim
34 words
A film as claimed in claim 1, wherein said two outer layers comprise said stabilizer in an amount of at least about 0.3% by weight, calculated on total weight of said two outer layers.
Claim 12
Dependent Claim
25 words
A film as claimed in claim 10, wherein said amount of stabilizer is within the range of from about 0.3 to about 1.0% by weight.
Claim 13
Dependent Claim
24 words
A film as claimed in claim 11, wherein said amount of stabilizer is within the range from about 0.3 to about 0.5% by weight.
Claim 14
Dependent Claim
19 words
A film as claimed in claim 1, having a total thickness of from about 4 to about 30 μm.
Claim 15
Dependent Claim
23 words
A film as claimed in claim 13, wherein the total thickness is within the range of from about 6 to about 20 μm.
Claim 16
Dependent Claim
25 words
A film as claimed in claim 1, wherein each of said two outer layers has a thickness of from about 0.3 to about 2.0 μm.
Claim 17
Dependent Claim
25 words
A film as claimed in claim 15, wherein each of said two outer layers has a thickness of from about 0.4 to about 0.8 μm.
Claim 18
Dependent Claim
16 words
A film as claimed in claim 15, wherein said two outer layers are of equal thickness.
Claim 19
Dependent Claim
33 words
A film as claimed in claim 15, wherein each of said two outer layers has a maximum surface roughness R z of up to about 1.5 μm, determined in accordance to DIN 4768.
Claim 20
Dependent Claim
21 words
A film as claimed in claim 18, wherein said surface roughness R z is from about 0.08 to about 0.35 μm.
Claim 21
Dependent Claim
18 words
A film as claimed in claim 18, wherein both of said two outer layers have identical surface roughness.
Claim 22
Dependent Claim
20 words
A film as claimed in claim 18, wherein the surface roughness of each of said two outer layers is different.
Claim 23
Dependent Claim
45 words
An electric film capacitor comprising: at least two films as claimed in claim 1, and at least two metal layers selected from the group consisting of aluminum, tin and lead/tin alloy, wherein the films and metal layers are contiguous to one another in alternating relationship.
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) | 1990-09-07 | 1991-03-09 | 1991-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-07 | 1995-03-09 | 1995-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-07 | 1999-03-09 | 1999-09-08 | $7700.00 | Window Closed / Lapsed |