US3840400A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording member
Assignee: Fujifilm Holdings Corp
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Filing: 1972-04-12
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Granted: 1974-10-08
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Expires: 1992-04-12
Abstract
Abstract A magnetic recording member in which a powder of a ferromagnetic -chromium dioxide or a derivative thereof is dispersed in a binder -and the dispersion is coated on a support, in which the binder is -a composition comprising at least three components, a vinyl chloridevinylidene -chloride copolymer an epoxy resin and a polyisocyanate is disclosed.
Inventors
- 👤 Y Yamada
- 👤 G Akashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; G11B5/7022; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12063; Y10T428/12104; Y10T428/12111; Y10T428/25; Y10T428/256; Y10T428/31504; Y10T428/31511; Y10T428/31515; Y10T428/31522; Y10T428/31529; Y10T428/31551; Y10T428/31573; Y10T428/3158; Y10T428/31605; Y10T428/31609
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
95 words
A MAGNETIC RECORDING MEMBER COMPRISING A NONMAGNETIC SUPPORT HAVING COATED THEREON A FERROMAGNETIC CHROMIUM DIOXIDE DISPERSED IN A BINDER, SAID BINDER COMPRISING A VINYL CHLORIDE-VINYLIDENE CHLORIDE COPOLYMER, AN EPOXY RESIN AND A POLYISOCYANATE, WHEREIN THE MOLAR RATIO OF SAID VINYL CHLORIDE TO SAID VINYLIDENE CHLORIDE RANGES FROM ABOUT 95:5 TO ABOUT 60:40, AND THE WEIGHT RATIO OF SAID COPOLYMER TO SAID EPOXY RESIN RANGES FROM ABOUT 5:95 TO ABOUT 80:20 AND WHEREIN THE AMOUNT OF SAID POLYISOCYANATE RANGES FROM ABOUT 9 TO ABOUT 40% BY WEIGHT BASED ON THE TOTAL WEIGHT OF SAID BINDER COMPOSITION.
Claim 2
Dependent Claim
95 words
A MAGNETIC RECORDING MEMBER COMPRISING A NONMAGNETIC SUPPORT HAVING COATED THEREON A FERROMAGNETIC CHROMIUM DIOXIDE DISPERSED IN A BINDER, SAID BINDER COMPRISING A VINYL CHLORIDE-VINYLIDENE CHLORIDE COPOLYMER, AN EPOXY RESIN AND A POLYISOCYANATE, WHEREIN THE MOLAR RATIO OF SAID VINYL CHLORIDE TO SAID VINYLIDENE CHLORIDE RANGES FROM ABOUT 95:5 TO ABOUT 60:40, AND THE WEIGHT RATIO OF SAID COPOLYMER TO SAID EPOXY RESIN RANGES FROM ABOUT 5:95 TO ABOUT 80:20 AND WHEREIN THE AMOUNT OF SAID POLYISOCYANATE RANGES FROM ABOUT 9 TO ABOUT 40% BY WEIGHT BASED ON THE TOTAL WEIGHT OF SAID BINDER COMPOSITION.
Claim 3
Dependent Claim
34 words
The magnetic recording of claim 1, wherein the weight ratio of the components of the binder composition are within the area enclosed by the curved line in the ternary phase diagram of the drawing.
Claim 4
Dependent Claim
20 words
The magnetic recording member of claim 1, wherein said support is a metal or a high molecular weight polymer film.
Claim 5
Dependent Claim
26 words
The magnetic recording member of claim 1, wherein the molar ratio of said vinyl chloride to said vinylidene chloride ranges from about 90:10 to about 70:30.
Claim 6
Dependent Claim
52 words
The magnetic recording member of claim 1, wherein the degree of polymerization of said copolymer ranges from about 0.3 to about 0.8 and the molecular weight of said epoxy resin ranges from about 300 to about 3,000, said epoxy resin having less than 0.5 free hydroxy group per 100g of epoxy resin.
Claim 7
Dependent Claim
77 words
The magnetic recording member of claim 1, wherein said ferromagnetic chromium dioxide is ferromagnetic chromium dioxIde or a modified ferromagnetic chromium dioxide material containing less than about 5% by weight based on the total weight of the material of an additive selected from the group consisting of ruthenium, tin, antimony, titanium, vandium, manganese, iron, cobalt, nickel, fluorine, phosphorus, arsenic, bismuth, niobium, tantalum, sodium, potassium, lithium, cesium, cadmium, tellurium, beryllium, boron, magnesium, zinc, ziroconium, platinum, gold, and mercury.
Claim 8
Dependent Claim
22 words
The magnetic recording member of claim 6, wherein said additive is present at a level of from 0.5 to 2% by weight.
Claim 9
Dependent Claim
23 words
The magnetic recording member of claim 6, wherein said ferromagnetic dioxide has a particle size ranging from about 0.3 to about 1 micron.
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) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |