US3634137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1969-09-24
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Granted: 1972-01-11
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Expires: 1989-09-24
Abstract
Abstract A magnetic recording medium comprising a polypropylene film as a support and a magnetic layer of magnetic powders dispersed in chlorinated polypropylene as a binder.
Inventors
- 👤 Goro Akashi
- 👤 Yasuyuki Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:26
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31855; Y10T428/31859; Y10T428/3187; Y10T428/31873; Y10T428/31877; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
26 words
The magnetic recording medium of claim 1 wherein the ratio by weight of said magnetic powders to said chlorinated polypropylene binder varies from 300:70 to 300:150.
Claim 2
Dependent Claim
36 words
The magnetic recording medium of claim 1 wherein said magnetic powders comprise at least one member selected from a group consisting of gamma -Fe2O3, Fe3O4, chromium dioxide, iron-cobalt-copper alloy, barium ferrite powders and zinc ferrite powders.
Claim 3
Dependent Claim
25 words
The magnetic recording medium of claim 1 wherein x varies from 0.29 to 0.77 and wherein n is an integer of from 400 to 600.
Claim 4
Dependent Claim
74 words
A magnetic recording medium comprising a polypropylene film support and a magnetic recording layer disposed thereon comprising magnetic powders dispersed in a binder comprising at least 50 percent by weight chlorinated polypropylene and up to 50 percent by weight of a resin compatible with said chlorinated polypropylene, said chlorinated polypropylene being represented by the formula -(C3H6-xClx)n -, wherein x varies from 0.27 to 2.60 and n is an integer of from 300 to 800.
Claim 5
Dependent Claim
23 words
The magnetic recording medium of claim 5 wherein the weight ratio of said magnetic powders to said binder varies from 300:70 to 300:150.
Claim 6
Dependent Claim
36 words
The magnetic recording medium of claim 5 wherein said magnetic powders comprise at least one member selected from a group consisting of gamma -Fe2O3, Fe3O4, iron-cobalt-copper alloy, chromium dioxide, barium ferrite powders and zinc ferrite powders.
Claim 7
Dependent Claim
25 words
The magnetic recording medium of claim 5 wherein x varies from 0.29 to 0.77 and wherein n is an integer of from 400 to 600.
Claim 8
Dependent Claim
38 words
The magnetic recording medium of claim 5 wherein said binder comprises from 70 to 50 percent by weight of said chlorinated polypropylene and from 30 to 50 percent by weight of said resin compatible with said chlorinated polypropylene.
Claim 9
Dependent Claim
26 words
The magnetic recording medium of claim 9 wherein said binder contains from 5 to 10 percent by weight of said resin compatible with said chlorinated polypropylene.
Claim 10
Dependent Claim
41 words
The magnetic recording medium of claim 5 wherein said resin compatible with said chlorinated polypropylene is a butylated urea resin, a phenol resin, a maleic acid resin, an epoxy resin, an acrylonitrile copolymer or an alkyd resin modified by acrylic acid.
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |