US3650828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic coating formulation for recording tape
Assignee: Karex Inc
•
Filing: 1969-09-04
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Granted: 1972-03-21
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Expires: 1989-09-04
Abstract
Abstract A polymeric binder for magnetic coating exhibiting excellent wear and aging characteristics comprised of a mixture of a high molecular weight vinyl chloride-vinyl acetate or a polyvinyl acetal having a glass transition temperature (Tg) in excess of 70* C. and a thermoplastic polyurethane-polyurea, hydroxylfunctional elastomer which is a reaction product of a mixture of a polyesterdiol, a hydrocarbon diol, a diphenyl sulfone diamine and an organic diisocyanate.
Inventors
- 👤 Louis M Higashi
- 👤 Herbert R Mcevers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:02
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; G11B5/7022; C; C08; C08K; C08K3/00; C08K3/02; C08K3/04; C08K3/18; C08K3/20; C08K3/22; C08L; C08L27/00; C08L27/02; C08L27/04; C08L27/06; C08L29/00; C08L29/14; C08L75/00; C08L75/04; C09; C09D; C09D127/00; C09D127/02; C09D127/04; C09D127/06; C08L75/12; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31565; Y10T428/31573; Y10T428/31576; Y10T428/3158; Y10T428/31609
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
22 words
A magnetic recording medium in accordance with claim 1 wherein said modifier is further characterized as being derived from a diamine sulfone.
Claim 2
Dependent Claim
141 words
A magnetic recording medium in accordance with claim 1 wherein said thermoplastic polyurethane-polyurea modifying resin is the cured reaction product of from about 1.5-1.7 mols of an organic diisocyanate with a mixture which comprises from about 0.4 to about 0.6 mol of a hydrocarbon diol having from two to about 10 carbon atoms and having terminal hydroxyl groups, from about 0.03 to about 0.05 mol of a diamine diphenyl sulfone, and 1.0 mol of a polymeric polyester condensation reaction product of 1,4-butane diol and adipic acid having a molecular weight of from about 700 to about 1,500 and an acid number of less than about 10, wherein the isocyanate groups of the diisocyanate are equal to from about 92 to about 97 percent of the total reactive hydrogens supplied by the polymeric polyester, the hydrocarbon diol, and the diamine diphenyl sulfone.
Claim 3
Dependent Claim
43 words
A magnetic recording medium in accordance with claim 1 wherein said coating includes about 65-85 parts by weight of said magnetic particles and further includes about 1.4-2.7 parts by weight of a dispersing agent, and about 0.4-1.5 parts by weight of a lubricant.
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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) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |