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US4431712A
Expired / Lapsed
US
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Magnetic recording medium of ferromagnetic particles and binder
Assignee: Fujifilm Holdings Corp
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Filing: 1982-02-10
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Granted: 1984-02-14
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Expires: 2002-02-10
Abstract
Abstract A magnetic recording medium having a non-magnetic base overlaid with a magnetic layer containing ferromagnetic particles and a binder is disclosed. The ferromagnetic particles are metal particles and the binder is composed of (a) carboxyl-containing vinyl chloride/vinyl acetate copolymer, (b) a polyurethane resin and (c) a polyisocyanate compound.
Inventors
- 👤 Akihiro Matsufuji
- 👤 Akira Kasuga
- 👤 Hajime Miyatsuka
- 👤 Masashi Aonuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; G11B5/7022; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
59 words
A magnetic recording medium, comprising: a non-magnetic support base; a magnetic layer overlaid on a surface of said non-magnetic support base, said magnetic layer comprising ferromagnetic particles and a binder, said ferromagnetic particles being metal particles and said binder comprising: (a) a copolymer of unsaturated carboxylic acid/vinyl chloride/vinyl acetate copolymer, (b) a polyurethane resin and (c) a polyisocyanate compound.
Claim 2
Dependent Claim
59 words
A magnetic recording medium, comprising: a non-magnetic support base; a magnetic layer overlaid on a surface of said non-magnetic support base, said magnetic layer comprising ferromagnetic particles and a binder, said ferromagnetic particles being metal particles and said binder comprising: (a) a copolymer of unsaturated carboxylic acid/vinyl chloride/vinyl acetate copolymer, (b) a polyurethane resin and (c) a polyisocyanate compound.
Claim 3
Dependent Claim
29 words
A magnetic recording medium as claimed in claim 1, wherein said component (a) is comprised of vinyl chloride:vinyl acetate:polymerizable unsaturated carboxylic acid, in a copolymerization ratio of 80-95:3-20:1-5, respectively.
Claim 4
Dependent Claim
22 words
A magnetic recording medium as claimed in claim 1, wherein said polyurethane resin has a molecular weight of from 10,000 to 200,000.
Claim 5
Dependent Claim
30 words
A magnetic recording medium as claimed in claim 1, wherein the weight ratio of (a) carboxyl-containing vinyl chloride/vinyl acetate copolymer to the (b) polyurethane resin is from 85:15 to 10:90.
Claim 6
Dependent Claim
17 words
A magnetic recording medium as claimed in claim 4, wherein said ratio is from 70:30 to 50:50.
Claim 7
Dependent Claim
42 words
A magnetic recording medium as claimed in claim 1, wherein the weight ratio of the (c) polyisocyanate compound to the sum of the (a) carboxyl-containing vinyl chloride/vinyl acetate copolymer and (b) polyurethane resin is within the range of from 40:60 to 10:90.
References Cited (Backward Citations)
US4289828A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-13 | 1987-08-15 | 1988-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-13 | 1991-08-15 | 1992-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-13 | 1995-08-15 | 1996-02-14 | $7700.00 | Window Closed / Lapsed |