Patent US3290359A successfully refreshed from Google Patents.
US4409291A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1981-03-26
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Granted: 1983-10-11
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Expires: 2001-03-26
Abstract
Abstract A magnetic recording medium is described comprising a non-magnetic support having formed thereon a magnetic layer comprising a binder and fine ferromagnetic particles dispersed therein, said binder containing a polyester polyurethane prepared by reacting poly(1,6-hexane adipate) with 4,4'-diphenylmethane diisocyanate.
Inventors
- 👤 Hiroshi Ogawa
- 👤 Akira Kasuga
- 👤 Yasuo Tamai
- 👤 Yasuyuki Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:30
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; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31565; Y10T428/31609
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
83 words
A magnetic recording medium, comprising: a non-magnetic support; and a magnetic layer formed on a surface of said non-magnetic support, said layer comprising fine ferromagnetic particles dispersed in a binder, said binder comprised of: a polyester polyurethane in an amount of at least 5 wt%, said polyester polyurethane prepared by reacting poly(1,6-hexane adipate) with 4,4-diphenylmethane diisocyanate; and a vinyl chloride acetate resin selected from the group consisting of vinyl chloride/vinyl acetate copolymer, vinyl chloride/vinyl acetate/vinyl alcohol copolymer and vinyl chloride/vinyl acetate/maleic anhydride copolymer.
Claim 2
Dependent Claim
83 words
A magnetic recording medium, comprising: a non-magnetic support; and a magnetic layer formed on a surface of said non-magnetic support, said layer comprising fine ferromagnetic particles dispersed in a binder, said binder comprised of: a polyester polyurethane in an amount of at least 5 wt%, said polyester polyurethane prepared by reacting poly(1,6-hexane adipate) with 4,4-diphenylmethane diisocyanate; and a vinyl chloride acetate resin selected from the group consisting of vinyl chloride/vinyl acetate copolymer, vinyl chloride/vinyl acetate/vinyl alcohol copolymer and vinyl chloride/vinyl acetate/maleic anhydride copolymer.
Claim 3
Dependent Claim
21 words
A magnetic recording medium as in claim 1 wherein said polyester polyurethane has a molecular weight of from 50,000 to 200,000.
Claim 4
Dependent Claim
27 words
A magnetic recording medium as in claim 1 wherein said polyester polyurethane is prepared by reacting a poly(1,6-hexane adipate) terminated with a hydroxyl group with 4,4'-diphenylmethane diisocyanate.
Claim 5
Dependent Claim
28 words
A magnetic recording medium as in claim 1, 2, or 3, wherein the polyester polyurethane is prepared by conducting the reaction in the presence of a chain extender.
Claim 6
Dependent Claim
26 words
A magnetic recording medium as in claim 1, 2, or 3, wherein the binder contains said polyester polyurethane in an amount of at least 10 wt%.
Claim 7
Dependent Claim
48 words
A magnetic recording medium as in claim 1, 2, or 3, wherein polyisocyanate compound is used to cure the magnetic layer, and the binder contains said polyester polyurethane in an amount of at least 15 wt% and said polyisocyanate compound in an amount of at least 5 wt%.
Claim 8
Dependent Claim
50 words
A magnetic recording medium as in claim 1, 2, or 3, wherein polyisocyanate compound is used to cure the magnetic layer, and the binder contains said polyester polyurethane in an amount of at least 20 wt% and said polyisocyanate compound is used in an amount of at least 10 wt%.
Claim 9
Dependent Claim
36 words
A magnetic recording medium as in claim 1, 2, or 3, wherein the binder is used in an amount of from 10 to 50 parts by weight per 100 parts by weight of the ferromagnetic particles.
Claim 10
Dependent Claim
18 words
A magnetic recording medium as claimed in claim 1, wherein said resin is vinyl chloride/vinyl acetate/vinyl alcohol copolymer.
Claim 11
Dependent Claim
47 words
A magnetic recording medium as claimed in claim 9, wherein polyisocyanate compound is used to cure said magnetic layer, said binder containing said polyester urethane in an amount of at least 15 weight % and said polyisocyanate compound is an amount of at least 5 weight %.
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) | 1986-10-10 | 1987-04-11 | 1987-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-10 | 1991-04-11 | 1991-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-10 | 1995-04-11 | 1995-10-11 | $7700.00 | Window Closed / Lapsed |