Patent US3929658A successfully refreshed from Google Patents.
US3929658A
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Magnetic recording compositions and elements of low abrasiveness and process for making them
Assignee: EIDP Inc
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Filing: 1974-12-02
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Granted: 1975-12-30
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Expires: 1994-12-02
Abstract
Abstract Magnetic recording compositions of low abrasiveness comprising, dispersed in an organic polymeric binder, ferromagnetic particles and finely divided particles of nonferromagnetic metal oxide having a Moh hardness of 5.5 or less, are formed into magnetic recording layers.
Inventors
- 👤 Grant A Beske
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:46
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/708; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
103 words
IN A MAGNETIC RECORDING COMPOSITION COMPRISING FERROMAGNETIC PARTICLES HAVING A MEAN PARTICLE LENGTH NOT GREATER THAN ABOUT 10 MICRONS DISPERSED IN AN ORGANIC POLYMERIC BINDER, THE IMPROVEMENT WHEREIN SAID COMPOSITION FURTHER COMPRISES FROM ABOUT 2 TO ABOUT 20 PERCENT, BASED UPON THE WEIGHT OF SAID FERROMAGNETIC PARTICLES, OF FINELY DIVIDED PARTICLES OF AT LEAST ONE NONFERROMAGNETIC METAL OXIDE HAVING A HARDNESS OF 5.5 OR LESS ON THE MOH SCALE SELECTED FROM THE GROUP CONSISTING OF AMATASE TITANIUM DIOXIDE, MOLYBDENUM TRIOXIDE, BRUCITE, CALAMINE, CHROMITE, CUPRITE, EMMONSITE, HAUSMANNITE, TENORITE AND ZINCITE AND A PARTICLE SIZE IN THE RANGE OF ABOUT 0.2 TO ABOUT 5.0 MICRONS.
Claim 2
Dependent Claim
103 words
IN A MAGNETIC RECORDING COMPOSITION COMPRISING FERROMAGNETIC PARTICLES HAVING A MEAN PARTICLE LENGTH NOT GREATER THAN ABOUT 10 MICRONS DISPERSED IN AN ORGANIC POLYMERIC BINDER, THE IMPROVEMENT WHEREIN SAID COMPOSITION FURTHER COMPRISES FROM ABOUT 2 TO ABOUT 20 PERCENT, BASED UPON THE WEIGHT OF SAID FERROMAGNETIC PARTICLES, OF FINELY DIVIDED PARTICLES OF AT LEAST ONE NONFERROMAGNETIC METAL OXIDE HAVING A HARDNESS OF 5.5 OR LESS ON THE MOH SCALE SELECTED FROM THE GROUP CONSISTING OF AMATASE TITANIUM DIOXIDE, MOLYBDENUM TRIOXIDE, BRUCITE, CALAMINE, CHROMITE, CUPRITE, EMMONSITE, HAUSMANNITE, TENORITE AND ZINCITE AND A PARTICLE SIZE IN THE RANGE OF ABOUT 0.2 TO ABOUT 5.0 MICRONS.
Claim 3
Dependent Claim
45 words
The magnetic recording composition of claim 1 wherein said ferromagnetic particles comprise particles of acicular chromium dioxide having a mean particle lengTh of less than about 10 microns, with no more than about 10 percent of the particles having a length greater than 10 microns.
Claim 4
Dependent Claim
29 words
The magnetic recording composition of claim 1 wherein said particles of nonferromagnetic metal oxide are selected from the group consisting of anatase titanium dioxide particles and molybdenum trioxide particles.
Claim 5
Dependent Claim
29 words
The magnetic recording composition of claim 2 wherein said particles of nonferromagnetic metal oxide are selected from the group consisting of anatase titanium dioxide particles and molybdenum trioxide particles.
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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) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |