US4476035A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic coating for magnetic recording media
Assignee: Denka Co Ltd
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Filing: 1982-12-28
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Granted: 1984-10-09
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Expires: 2002-12-28
Abstract
Abstract A magnetic coating for a magnetic recording medium prepared by kneading a copolymer comprising vinyl chloride, a vinyl carboxylate ester, vinyl alcohol and an unsaturated dicarboxylic acid and/or an unsaturated dicarboxylic acid anhydride; a thermosetting resin; and a magnetic powder, in an organic solvent.
Inventors
- 👤 Shigeto Miyoshi
- 👤 Kanehisa Hanabusa
- 👤 Toshio Kagami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:04
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; Y10T428/31609
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
45 words
A magnetic coating for magnetic recording media comprising: a copolymer comprising: (A) vinyl chloride (B) a vinyl carboxylate ester (C) vinyl alcohol, and (D) an unsaturated dicarboxylic acid and/or an unsaturated dicarboxylic acid anhydride; a thermosetting polyurethane resin; a magnetic powder; and an organic solvent.
Claim 2
Dependent Claim
45 words
A magnetic coating for magnetic recording media comprising: a copolymer comprising: (A) vinyl chloride (B) a vinyl carboxylate ester (C) vinyl alcohol, and (D) an unsaturated dicarboxylic acid and/or an unsaturated dicarboxylic acid anhydride; a thermosetting polyurethane resin; a magnetic powder; and an organic solvent.
Claim 3
Dependent Claim
21 words
The magnetic coating according to claim 1, wherein the average degree of polymerization of said copolymer is from 100 to 900.
Claim 4
Dependent Claim
21 words
The magnetic coating according to claim 2, wherein the average degree of polymerization of said copolymer is from 150 to 750.
Claim 5
Dependent Claim
52 words
The magnetic coating according to claim 1, wherein said copolymer comprises 50%-90% by weight of component (A); 3%-20% by weight of component (C) based on the sum of the components (A), (B) and (C); and 0.1%-5% by weight of component (D) based on the sum of the components (A), (B) and (C).
Claim 6
Dependent Claim
54 words
The magnetic coating according to claim 4, wherein said copolymer comprises 50%-90% by weight of the component (A); 3%-20% by weight of component (C) based on the sum of the components (A), (B) and (C); and the 1%-5% by weight of component (D) based on the sum of the components (A), (B) and (C).
Claim 7
Dependent Claim
25 words
The magnetic coating according to claim 1, wherein said component (D) of said copolymer contains said unsaturated dicarboxylic acid and said unsaturated dicarboxylic acid anhydride.
Claim 8
Dependent Claim
27 words
The magnetic coating according to claim 6, wherein said unsaturated dicarboxylic acid anhydride is an intramolecular anhydride of the same dicarboxylic acid as said unsaturated dicarboxylic acid.
Claim 9
Dependent Claim
30 words
The magnetic coating according to claim 1, wherein said copolymer is prepared by copolymerizing three components corresponding to components (A), (B), and (D), and then partially saponifying the component (B).
Claim 10
Dependent Claim
29 words
The magnetic coating according to claim 1, wherein said component (D) is at least one compound selected from the group consisting of vinyl acetate, vinyl propionate, and vinyl stearate.
Claim 11
Dependent Claim
14 words
The magnetic coating according to claim 9, wherein said component (B) is vinyl acetate.
Claim 12
Dependent Claim
35 words
The magnetic coating according to claim 1, wherein said component (D) is at least one compound selected from the group consisting of maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid and fumaric anhydride.
Claim 13
Dependent Claim
17 words
The magnetic coating according to claim 11, wherein said component (D) is maleic acid and/or maleic anhydride.
References Cited (Backward Citations)
JPS54151406A
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JPS54151408A
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JPS54151416A
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JPS54151412A
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US4388376A
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US4323628A
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US4352859A
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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) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |