Patent US4833019A successfully refreshed from Google Patents.
US4833019A
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Magnetic recording tape comprising a support film having a high transverse direction modulus
Assignee: 3M Co
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Filing: 1987-02-17
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Granted: 1989-05-23
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Expires: 2007-02-17
Abstract
Abstract The invention provides a magnetic recording tape having a substantial increase in electromagnetic and head cleaning capabilities comprising a thin magnetic layer carried on a non-magnetic support film, the film having a ratio of Young's modulus in the longitudinal direction to Young's modulus in the transverse direction sufficiently low, typically between about 0.3 and 0.5, to provide a tape with the improved properties.
Inventors
- 👤 Nat J. Suwarnasarn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:02
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/739; G11B5/73923; G11B5/73927; G11B5/736; G11B5/73929; G11B5/74; G11B5/78; G11B2220/00; G11B2220/90; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31786
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
64 words
A magnetic recording tape comprising: a magnetic layer carried on a non-magnetic support film, said support film having a thickness of between about 5 and 25 microns, a Young's modulus in the longitudinal direction of at least 350 Kg/mm 2 and a ratio of Young's modulus in the longitudinal direction of Young's modulus in the transverse direction of between about 0.3 and about 0.45.
Claim 2
Dependent Claim
64 words
A magnetic recording tape comprising: a magnetic layer carried on a non-magnetic support film, said support film having a thickness of between about 5 and 25 microns, a Young's modulus in the longitudinal direction of at least 350 Kg/mm 2 and a ratio of Young's modulus in the longitudinal direction of Young's modulus in the transverse direction of between about 0.3 and about 0.45.
Claim 3
Dependent Claim
34 words
The magnetic recording tape of claim 1 wherein said support film has a ratio of Young's modulus in the longitudinal direction to Young's modulus in the transverse direction is between about 0.34 and 0.45.
Claim 4
Dependent Claim
21 words
The magnetic recording tape of claim 1 wherein said support film has a thickness of between about 8 and 16 microns.
Claim 5
Dependent Claim
22 words
The magnetic recording tape of claim 1, wherein said Young's modulus in the longitudinal direction is at least 430 kg/mm 2 .
Claim 6
Dependent Claim
21 words
The magnetic recording tape of claim 1 wherein said magnetic layer has a thickness of between about 0.005 and 10 microns.
Claim 7
Dependent Claim
20 words
The magnetic recording tape of claim 5 wherein said magnetic layer comprises a magnetic pigment dispersed in a resinous binder.
Claim 8
Dependent Claim
21 words
The magnetic recording tape of claim 6 wherein said magnetic layer has a thickness of between about 1.5 and 7.5 microns.
Claim 9
Dependent Claim
44 words
The magnetic recording tape of claim 1 wherein said magnetic layer has a Young's modulus in the longitudinal direction of between about 350 and 2800 Kg/mm 2 and a Young's modulus in the transverse direction of between about 200 and 1500 Kg/mm 2 .
Claim 10
Dependent Claim
44 words
The magnetic recording tape of claim 8 wherein said magnetic layer has a Young's modulus in the longitudinal direction of between about 700 and 2100 Kg/mm 2 and a Young's modulus in the transverse direction of between about 350 and 1100 Kg/mm 2 .
Claim 11
Dependent Claim
50 words
A non-magnetic film having a thickness of between about 5 and 25 microns, a Young's modulus in the longitudinal direction of at least 350 Kg/mm 2 and a ratio of Young's modulus in the longitudinal direction to Young's modulus in the transverse direction of between about 0.3 and about 0.45.
Claim 12
Dependent Claim
50 words
A non-magnetic film having a thickness of between about 5 and 25 microns, a Young's modulus in the longitudinal direction of at least 350 Kg/mm 2 and a ratio of Young's modulus in the longitudinal direction to Young's modulus in the transverse direction of between about 0.3 and about 0.45.
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) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |