Patent US4091924A successfully refreshed from Google Patents.
US4091924A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermally resistant magnetic tape enclosed in protective container
Assignee: EMAG LLC
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Filing: 1976-01-02
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Granted: 1978-05-30
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Expires: 1996-01-02
Abstract
Abstract An improved magnetic tape having the property of retaining magnetic data even when spooled and subjected to high temperature environments. This thermal resistance is suitably achieved by providing a backing coating which contacts the magnetic-particle-bearing facing coating of the tape and is chemically incompatible therewith. Pairs of chemically-incompatible coatings include polyester polyurethane-polyether-polyurethane; polyfluorinated hydrocarbons-polyurethane. A conductive furnace carbon black is advantageously used in the backing coating, and the substrate is, suitably, temperature-resistant polyimide.
Inventors
- 👤 Gerald S. Newton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:16
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; G11B5/73; G11B5/735; G11B5/7356; G11B5/7358; Y; Y10; Y10S; Y10S206/00; Y10S206/819; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31562; Y10T428/31609; Y10T428/31721
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
88 words
In a magnetic recording apparatus of the type wherein a reeled magnetic tape is enclosed in a sealed, protective container, the improvement wherein said tape is a magnetic tape comprising a substrate formed of a synthetic organic resin, a first magnetic pigment containing coating on one side of said substrate and a second non-magnetic conductive pigment containing coating on the other side of said substrate wherein one of said coatings has a polyester polyurethane resin matrix and the other of said coatings has a polyether polyurethane resin matrix.
Claim 2
Dependent Claim
88 words
In a magnetic recording apparatus of the type wherein a reeled magnetic tape is enclosed in a sealed, protective container, the improvement wherein said tape is a magnetic tape comprising a substrate formed of a synthetic organic resin, a first magnetic pigment containing coating on one side of said substrate and a second non-magnetic conductive pigment containing coating on the other side of said substrate wherein one of said coatings has a polyester polyurethane resin matrix and the other of said coatings has a polyether polyurethane resin matrix.
Claim 3
Dependent Claim
16 words
Apparatus as defined in claim 1 wherein said resins are crosslinked by a polyfunctional cross-linking agent.
Claim 4
Dependent Claim
72 words
In a magnetic recording apparatus of the type wherein a reeled magnetic tape is enclosed in a sealed, protective container, the improvement wherein 1. said tape has a polymeric coating on each face thereof and each of said coatings has a different synthetic polymer matrix for the pigment contained therein, and said different synthetic polymers are chemically incompatible with each other, and 2. the non-magnetic conductive pigment is a conductive carbon black.
Claim 5
Dependent Claim
72 words
In a magnetic recording apparatus of the type wherein a reeled magnetic tape is enclosed in a sealed, protective container, the improvement wherein 1. said tape has a polymeric coating on each face thereof and each of said coatings has a different synthetic polymer matrix for the pigment contained therein, and said different synthetic polymers are chemically incompatible with each other, and 2. the non-magnetic conductive pigment is a conductive carbon black.
Claim 6
Dependent Claim
16 words
A recording apparatus a defined in claim 3 wherein said carbon black is a furnace black.
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) | 1981-05-29 | 1981-11-28 | 1982-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-29 | 1985-11-28 | 1986-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-29 | 1989-11-28 | 1990-05-30 | $7700.00 | Window Closed / Lapsed |