Patent US4429024A successfully refreshed from Google Patents.
US4429024A
Expired / Lapsed
US
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Method of making antistatic magnetic recording tapes and recording tapes
Assignee: Shin-Etsu Chemical Co Ltd
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Filing: 1982-08-06
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Granted: 1984-01-31
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Expires: 2002-08-06
Abstract
Abstract The invention provides a novel means for solving and overcoming the problems in the magnetic recording tapes caused by the accumulation of static electricity during travelling of the tape affecting the quality of the reproduced sounds and picture images by playing the tape. The inventive method comprises providing at least one surface of the plastic-made film base with a layer of a plasma-polymerized gaseous compound of a specific type by exposing the surface of the film base to the atmosphere of low temperature plasma generated in the low pressure atmosphere of the gas or vapor of a compound such as an amine, organosilane, aliphatically unsaturated compound and aromatic compound, preferably, before coating the film base with a magnetic coating composition. The plasma-polymerized layer is effective to decrease the surface resistivity of the film base and to reduce the accumulation of static electricity induced by rubbing.
Inventors
- 👤 Susumu Ueno
- 👤 Hirokazu Nomura
- 👤 Kiyoshi Imada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:06
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/735; G11B5/739; G11B5/73923; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
47 words
An antistatic magnetic recording tape which comprises a film base made of a synthetic plastic resin, a layer of a plasma-polymerized gaseous compound provided on at least one surface of the film base and a magnetic layer provided on at least one surface of the film base.
Claim 2
Dependent Claim
47 words
An antistatic magnetic recording tape which comprises a film base made of a synthetic plastic resin, a layer of a plasma-polymerized gaseous compound provided on at least one surface of the film base and a magnetic layer provided on at least one surface of the film base.
Claim 3
Dependent Claim
43 words
The antistatic magnetic recording tape as claimed in claim 1 wherein the layer of the plasma-polymerized gaseous compound is provided on one of the surfaces of the film base and the magnetic layer is provided on the other surface of the film base.
Claim 4
Dependent Claim
43 words
The antistatic magnetic recording tape as claimed in claim 1 wherein the layer of the plasma-polymerized gaseous compound is provided on at least one surface of the film base and the magnetic layer is provided on the layer of the plasma-polymerized gaseous compound.
Claim 5
Dependent Claim
39 words
The antistatic magnetic recording tape as claimed in claim 1 wherein the magnetic layer is provided on at least one surface of the film base and the layer of the plasma-polymerized gaseous compound is provided on the magnetic layer.
Claim 6
Independent Claim
96 words
A method for the preparation of an antistatic magnetic recording tape which comprises exposing at least one surface of a film base made of a synthetic plastic resin to an atmosphere of low temperature plasma generated in a low pressure atmosphere of a gas or vapor of a gasifiable compound in the range from 0.001 Torr to 10 Torr to deposit a layer of the plasma-polymerized gasifiable compound on the surface of the film base and coating at least one surface of the film base with a magnetic coating composition to form a magnetic layer thereon.
Claim 7
Independent Claim
96 words
A method for the preparation of an antistatic magnetic recording tape which comprises exposing at least one surface of a film base made of a synthetic plastic resin to an atmosphere of low temperature plasma generated in a low pressure atmosphere of a gas or vapor of a gasifiable compound in the range from 0.001 Torr to 10 Torr to deposit a layer of the plasma-polymerized gasifiable compound on the surface of the film base and coating at least one surface of the film base with a magnetic coating composition to form a magnetic layer thereon.
Claim 8
Dependent Claim
59 words
The method for the preparation of an antistatic magnetic recording tape as claimed in claim 5 wherein only one of the surface of the film base is exposed to the atmosphere of low temperature plasma and the magnetic layer is formed on the other surface of the film base not exposed to the atmosphere of the low temperature plasma.
Claim 9
Dependent Claim
39 words
The method for the preparation of an antistatic magnetic recording tape as claimed in claim 5 wherein the gasifiable compound is selectded from the class consisting of amine compounds, organic silicon compounds, aliphatically unsaturated organic compounds and aromatic compounds.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-30 | 1987-08-01 | 1988-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-30 | 1991-08-01 | 1992-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-30 | 1995-08-01 | 1996-01-31 | $7700.00 | Window Closed / Lapsed |