US4267206A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of making high-temperature magnetic tape
Assignee: EMAG LLC
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Filing: 1979-10-12
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Granted: 1981-05-12
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Expires: 1999-10-12
Abstract
Abstract An improved, conventionally-spoolable, magnetic tape which can be unspooled and read after exposure to very high temperatures. The improvement is largely in a thermally resistant, non-adhering, anti-static backing system, used in conjunction with magnetic face coatings.
Inventors
- 👤 Robert A. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:58
CPC Classifications
B; B05; B05D; B05D5/00; B05D5/12; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
77 words
A process for coating a pre-polymerized polyurethane based binder system, dispersed in a tetrahydrofuran solvent system onto a polyimide substrate comprising the step of incorporating a quantity of dimethylformamide (DMF) into said binder system before said coating is carried out, thereupon coating said binder system onto said substrate, and removing said DMF by evaporation, wherein said quantity of DMF is effective to form means to increase the adherence between said pre-polymerized polyurethane binder system and said substrate.
Claim 2
Dependent Claim
77 words
A process for coating a pre-polymerized polyurethane based binder system, dispersed in a tetrahydrofuran solvent system onto a polyimide substrate comprising the step of incorporating a quantity of dimethylformamide (DMF) into said binder system before said coating is carried out, thereupon coating said binder system onto said substrate, and removing said DMF by evaporation, wherein said quantity of DMF is effective to form means to increase the adherence between said pre-polymerized polyurethane binder system and said substrate.
Claim 3
Dependent Claim
59 words
A process as defined in claim 1 wherein said coating is carried out on the opposite side of said substrate from a magnetic face coating and wherein said composition being coated is an anti-static and anti-blocking coating comprising, by weight, about 5 to 10% of pyrogenic silica and about 0.5 to 2% of silicone-oil based lubricant in the coating.
References Cited (Backward Citations)
US3941911A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-11 | 1984-11-10 | 1985-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-11 | 1988-11-10 | 1989-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-11 | 1992-11-10 | 1993-05-12 | $7700.00 | Window Closed / Lapsed |