US4187341A
Expired / Lapsed
US
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Magnetic recording tape
Assignee: Fujifilm Holdings Corp
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Filing: 1977-11-17
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Granted: 1980-02-05
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Expires: 1997-11-17
Abstract
Abstract In a magnetic recording tape having a total thickness of 4.0 to 14.5 microns, the base thickness to magnetic layer thickness ratio is from 2:3 to 3:2, the base Young's modulus to magnetic layer Young's modulus ratio is from 1:2 to 2:1 and the tensile strength at 0.5% elongation is 2ROOT d/16 Kg or more to the total thickness d (micron).
Inventors
- 👤 Masaaki Suzuki
- 👤 Osamu Suzuki
- 👤 Goro Akashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:58
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/26; Y10T428/266
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
68 words
A magnetic recording tape comprising a base layer and a magnetic layer, said tape having a total thickness of 4.0 to 14.5μ, a base to magnetic layer thickness ratio of 2:3 to 3:2, a base to magnetic layer Young's modulus ratio of 1:2 to 2:1 and a tensile strength at 0.5% elongation of at least √d/16 (Kg), where d is the total thickness (in microns) of the tape.
Claim 2
Dependent Claim
68 words
A magnetic recording tape comprising a base layer and a magnetic layer, said tape having a total thickness of 4.0 to 14.5μ, a base to magnetic layer thickness ratio of 2:3 to 3:2, a base to magnetic layer Young's modulus ratio of 1:2 to 2:1 and a tensile strength at 0.5% elongation of at least √d/16 (Kg), where d is the total thickness (in microns) of the tape.
Claim 3
Dependent Claim
31 words
The magnetic recording tape as claimed in claim 1, wherein the base is of a material selected from the group consisting of polyesters, polyolefins, cellulose derivatives, polycarbonates, non-magnetic metals and ceramics.
Claim 4
Dependent Claim
19 words
The magnetic recording tape as claimed in claim 1, wherein the base has a thickness of 2.4 to 8.7μ.
Claim 5
Dependent Claim
20 words
The magnetic recording tape as claimed in claim 1, wherein the magnetic layer contains a magnetic powder and a binder.
Claim 6
Dependent Claim
53 words
The magnetic recording tape as claimed in claim 4, wherein the magnetic powder is selected from the group consisting of fine powders of γ-Fe 2 O 3 , Co-doped γ-Fe 2 O 3 , Fe 3 O 4 , Co-doped Fe 3 O 4 , CrO 2 , Co-Ni-P alloys and Co-Ni-Fe alloys.
Claim 7
Dependent Claim
24 words
The magnetic recording tape as claimed in claim 4, wherein the binder is selected from the group consisting of thermoplastic resins and thermosetting resins.
Claim 8
Dependent Claim
20 words
The magnetic recording tape as claimed in claim 1, wherein the magnetic recording layer further contains dispersing agents and lubricants.
Claim 9
Dependent Claim
33 words
The magnetic recording tape as claimed in claim 1, wherein the magnetic layer is formed by coating onto the support base a magnetic powder, binder, dispersing agent and lubricant with an organic solvent.
Claim 10
Dependent Claim
31 words
The magnetic recording tape as claimed in claim 8, wherein the organic solvent is selected from the group consisting of ketones, alcohols, esters, ethers, glycol ethers, aromatic hydrocarbons and chlorinated hydrocarbons.
Claim 11
Dependent Claim
25 words
The magnetic recording tape as claimed in claim 1, wherein the magnetic layer has a Young's modulus of about 700 to 1890 Kg/mm 2 .
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) | 1983-02-04 | 1983-08-06 | 1984-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-04 | 1987-08-06 | 1988-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-04 | 1991-08-06 | 1992-02-05 | $7700.00 | Window Closed / Lapsed |