Patent US4429017A successfully refreshed from Google Patents.
US4429017A
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1982-12-06
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Granted: 1984-01-31
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Expires: 2002-12-06
Abstract
Abstract A magnetic recording medium is disclosed. The medium is comprised of a non-magnetic support base having a magnetic layer thereon. Magnetic layer is comprised of a binder having a ferromagnetic powder dispersed therein. The binder is comprised of a copolymer of vinyl chloride/vinylidene chloride/vinyl alcohol in a ratio of 20 to 89 wt % of vinyl chloride: 10 to 60 wt % of vinylidene chloride: 1 to 20 wt % of vinyl alcohol. By utilizing the particularly disclosed polymer as the binder the magnetic recording medium has a superior capacity with respect to reproducing original sound and images and also has improved running properties and durability.
Inventors
- 👤 Hiroshi Ogawa
- 👤 Yasuo Tamai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:51
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7023; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31605; Y10T428/31609; Y10T428/31678; Y10T428/31692; Y10T428/31699
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
60 words
A magnetic recording medium comprising a non-magnetic support base having thereon a magnetic recording layer having a ferromagnetic powder dispersed in a binder, the binder being comprised of a copolymer of vinyl chloride/vinylidene chloride/vinyl alcohol in a ratio of 20 to 89 wt% of vinyl chloride: 10 to 60 wt% of vinylidene chloride: 1 to 20 wt% of vinyl alcohol.
Claim 2
Dependent Claim
60 words
A magnetic recording medium comprising a non-magnetic support base having thereon a magnetic recording layer having a ferromagnetic powder dispersed in a binder, the binder being comprised of a copolymer of vinyl chloride/vinylidene chloride/vinyl alcohol in a ratio of 20 to 89 wt% of vinyl chloride: 10 to 60 wt% of vinylidene chloride: 1 to 20 wt% of vinyl alcohol.
Claim 3
Dependent Claim
40 words
A magnetic recording medium, as claimed in claim 1, wherein the ratio of the vinyl chloride/vinylidene chloride/vinyl alcohol is 35 to 75 wt% of vinyl chloride: 10 to 60 wt% of vinylidene chloride: 3 to 15 wt% of vinyl alcohol.
Claim 4
Dependent Claim
40 words
A magnetic recording medium as claimed in claim 2, wherein the ratio of the vinyl chloride/vinylidene chloride/vinyl alcohol is 35 to 75 wt% of vinyl chloride: 20 to 50 wt% of vinylidene chloride: 3 to 15 wt% of vinyl alcohol.
Claim 5
Dependent Claim
40 words
A magnetic recording medium as claimed in claim 1, wherein the ratio of the vinyl chloride/vinylidene chloride/vinyl alcohol is 20 to 89 wt% of vinyl chloride: 20 to 50 wt% of vinylidene chloride: 3 to 15 wt% of vinyl alcohol.
Claim 6
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 1, wherein the copolymer has a degree of polymerization of about 200 to about 700.
Claim 7
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 1, wherein the binder is comprised of 40% by weight or more of the copolymer.
Claim 8
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 6, wherein the binder is comprised of 60% by weight or more of the copolymer.
Claim 9
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 7, wherein the binder is comprised of 80% or more by weight of the copolymer.
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) | 1987-01-30 | 1987-08-01 | 1988-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-30 | 1991-08-01 | 1992-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-30 | 1995-08-01 | 1996-01-31 | $7700.00 | Window Closed / Lapsed |