US4336308A
Expired / Lapsed
US
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Magnetic recording media
Assignee: Fujifilm Holdings Corp
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Filing: 1979-09-11
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Granted: 1982-06-22
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Expires: 1999-09-11
Abstract
Abstract A magnetic recording medium and, more particularly, a magnetic recording medium based on a magnetic composition exhibiting high dispersibility of finely divided ferromagnetic powders and having excellent abrasion resistance is disclosed wherein the binder for the magnetic composition contains a 2-chloroacrylonitrile polymer and a thermoplastic polyurethane resin; in another embodiment of the invention the binder additionally contains a polyisocyanate.
Inventors
- 👤 Yasuyuki Yamada
- 👤 Kenichi Masuyama
- 👤 Nobuo Tsuji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:34
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; Y10T428/31609; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
36 words
In a magnetic recording medium comprising a nonmagnetic support and a recording layer comprising a finely divided ferromagnetic powder dispersed in a binder, the improvement wherein said binder comprises a 2-chloroacrylonitrile polymer and a thermoplastic polyurethane.
Claim 2
Dependent Claim
36 words
In a magnetic recording medium comprising a nonmagnetic support and a recording layer comprising a finely divided ferromagnetic powder dispersed in a binder, the improvement wherein said binder comprises a 2-chloroacrylonitrile polymer and a thermoplastic polyurethane.
Claim 3
Dependent Claim
15 words
The magnetic recording medium of claim 1, wherein said binder additionally contains a polyisocyanate compound.
Claim 4
Dependent Claim
34 words
The magnetic recording medium of claims 1 or 2, wherein said binder is present in an amount of about 10 to 80 parts by weight per 100 parts by weight finely divided ferromagnetic powder.
Claim 5
Dependent Claim
24 words
The magnetic recording medium of claim 2, wherein said polyisocyanate is an aliphatic diisocyanate, a cycloaliphatic diisocyanate, or an aromatic diisocyanate, and adducts thereof.
Claim 6
Dependent Claim
36 words
The magnetic recording medium of claim 2, wherein said polyisocyanate is present in an amount of about 5 to 60 parts by weight per 100 parts by weight of the mixture of 2-chloroacrylonitrile and the polyurethane.
Claim 7
Dependent Claim
22 words
The magnetic recording medium of claim 1, wherein said 2-acrylonitrile polymer has a weight average molecular weight of about 10,000 to 300,000.
Claim 8
Dependent Claim
19 words
The magnetic recording medium of claim 1, wherein said thermoplastic polyurethane is a polyester polyurethane or a polyether polyurethane.
Claim 9
Dependent Claim
21 words
The magnetic recording medium of claim 1, wherein said polyurethane has a weight average molecular weight of about 10,000 to 300,000.
Claim 10
Dependent Claim
26 words
The magnetic recording medium of claim 1, wherein said 2-chloroacrylontrile polymer and said polyurethane resin are present in a weight ratio of about 1:9 to 9:1.
Claim 11
Dependent Claim
26 words
The magnetic recording medium of claim 9, wherein said 2-chloroacrylonitrile polymer and said thermoplastic polyurethane are present in a weight ratio of about 3:7 to 7:3.
Claim 12
Dependent Claim
49 words
The magnetic recording medium of claim 1, wherein said 2-chloroacrylonitrile polymer is a homopolymer or a copolymer of 2-chloroacrylonitrile and up to 30 mol% of a monomer selected from the group consisting of vinyl chloride, vinyl acetate, vinylidene chloride, acrylonitrile, and an alkyl (C 1-8 ) acrylate or methacrylate.
Claim 13
Dependent Claim
40 words
The magnetic recording medium of claim 11, wherein said acrylate or methacrylate is ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, heptyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, heptyl methacrylate or octyl methacrylate.
Claim 14
Dependent Claim
16 words
A magnetic coating composition comprising a finely-divided ferromagnetic powder, 2-chloroacrylonitrile polymer and a thermoplastic polyurethane resin.
Claim 15
Dependent Claim
16 words
A magnetic coating composition comprising a finely-divided ferromagnetic powder, 2-chloroacrylonitrile polymer and a thermoplastic polyurethane resin.
Claim 16
Dependent Claim
15 words
The magnetic coating composition of claim 13, wherein said binder additionally contains a polyisocyanate compound.
Claim 17
Dependent Claim
34 words
The magnetic coating composition of claim 13 or 14, wherein said binder is present in an amount of about 10 to 80 parts by weight per 100 parts by weight finely divided ferromagnetic powder.
Claim 18
Dependent Claim
24 words
The magnetic coating composition of claim 14, wherein said polyisocyanate is an aliphatic diisocyanate, a cycloaliphatic diisocyanate, or an aromatic diisocyanate, and adducts thereof.
Claim 19
Dependent Claim
36 words
The magnetic coating composition of claim 14, wherein said polyisocyanate is present in an amount of about 5 to 60 parts by weight per 100 parts by weight of the mixture of 2-chloroacrylonitrile and the polyurethane.
Claim 20
Dependent Claim
49 words
The magnetic coating composition of claim 13, wherein said 2-chloroacrylonitrile polymer is a homopolymer or a copolymer of 2-chloroacrylonitrile and up to 30 mol% of a monomer selected from the group consisting of vinyl chloride, vinyl acetate, vinylidene chloride, acrylonitrile, and an alkyl (C 1-8 ) acrylate or methacrylate.
Claim 21
Dependent Claim
42 words
The magnetic coating composition of claim 18, wherein said acrylate or methacrylate is ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, heptyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, heptyl methacrylate or octyl methacrylate.
Claim 22
Dependent Claim
22 words
The magnetic coating composition of claim 13, wherein said 2-acrylonitrile polymer has a weight average molecular weight of about 10,000 to 300,000.
Claim 23
Dependent Claim
19 words
The magnetic coating composition of claim 13, wherein said thermoplastic polyurethane is a polyester polyurethane or a polyether polyurethane.
Claim 24
Dependent Claim
21 words
The magnetic coating composition of claim 13, wherein said polyurethane has a weight average molecular weight of about 10,000 to 300,000.
Claim 25
Dependent Claim
26 words
The magnetic coating composition of claim 13, wherein said 2-chloroacrylonitrile polymer and said polyurethane resin are present in a weight ratio of about 1:9 to 9:1.
Claim 26
Dependent Claim
26 words
The magnetic coating composition of claim 23, wherein said 2-chloroacrylonitrile polymer and said thermoplastic polyurethane are present in a weight ratio of about 3:7 to 7:3.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-21 | 1985-12-21 | 1986-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-21 | 1989-12-21 | 1990-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-21 | 1993-12-21 | 1994-06-22 | $7700.00 | Window Closed / Lapsed |