US4659626A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1985-07-01
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Granted: 1987-04-21
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Expires: 2005-07-01
Abstract
Abstract In a magnetic recording medium consisting of a base coated with a magnetic coating material, or a dispersion of magnetic particles in a resinous binder, the binder comprises a copolymer composed of vinyl chloride, a vinyl alkylcarboxylate, another monomer copolymerizable with vinyl chloride, and a saponified vinyl alkylcarboxylate and having an OH/CH absorption ratio according to the infrared absorption spectrum of 0.2 to 0.7, a polyurethane resin having in its molecule a --SO 3 M group wherein M represents an alkali metal atom, and a polyurethane resin or polyester resin or both containing no --SO 3 M group wherein M represents an alkali metal atom, and a polyisocyanate.
Inventors
- 👤 Kiyoto Fukushima
- 👤 Shigeru Takamatsu
- 👤 Eiji Kitaura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:31
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; Y10T428/31931; Y10T428/31935; Y10T428/31938
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
127 words
A magnetic recording medium which comprises a dispersion of magnetic particles in a resinous binder, and a base to which the dispersion is solidly applied, said resinous binder comprising a copolymer composed of vinyl chloride, a vinyl alkylcarboxylate, another monomer copolymerizable with vinyl chloride, and a saponified vinyl alkylcarboxylate and having an OH/CH absorption ratio according to the infrared absorption spectrum of 0.2 to 0.7, a polyurethane resin having in its molecule a --SO 3 M group in the range of about 10 to 1000 g equivalent 10 4 g and wherein M represents an alkali metal atom, and a rubbery binder ingredient comprising polyurethane resin or polyester resin or both containing no --SO 3 M group wherein M represents an alkali metal atom, and a polyisocyanate.
Claim 2
Dependent Claim
127 words
A magnetic recording medium which comprises a dispersion of magnetic particles in a resinous binder, and a base to which the dispersion is solidly applied, said resinous binder comprising a copolymer composed of vinyl chloride, a vinyl alkylcarboxylate, another monomer copolymerizable with vinyl chloride, and a saponified vinyl alkylcarboxylate and having an OH/CH absorption ratio according to the infrared absorption spectrum of 0.2 to 0.7, a polyurethane resin having in its molecule a --SO 3 M group in the range of about 10 to 1000 g equivalent 10 4 g and wherein M represents an alkali metal atom, and a rubbery binder ingredient comprising polyurethane resin or polyester resin or both containing no --SO 3 M group wherein M represents an alkali metal atom, and a polyisocyanate.
Claim 3
Dependent Claim
15 words
A magnetic recording medium according to claim 1 wherein the vinyl alkylcarboxylate is vinyl acetate.
Claim 4
Dependent Claim
15 words
A magnetic recording medium according to claim 1 wherein the vinyl alkylcarboxylate is vinyl propionate.
Claim 5
Dependent Claim
31 words
A magnetic recording medium according to claim 1 wherein another monomer copolymerizable with vinyl chloride is maleic acid, fumaric acid, acrylic acid, methacrylic acid, an ester thereof, or a combination thereof.
Claim 6
Dependent Claim
56 words
A magnetic recording medium according to any one of claims 1 to 4 wherein the copolymer comprises, all by weight on the basis thereof, 50 to 90% of vinyl chloride, 5 to 40% of a vinyl alkylcarboxylate, 0.5 to 5.0% of another monomer copolymerizable with vinyl chloride, and the remainder substantially of a saponified vinyl alkylcarboxylate.
Claim 7
Independent Claim
61 words
A medium according to any one of claims 1 to 4 wherein, on the basis of the total resin weight in the resinous binder, the copolymer accounts for 20 to 80%, the SO 3 M-containing polyurethane resin for 10 to 70%, the rubbery binder ingredient for 10 to 70%, and the polyisocyanate curing agent for 5 to 30%, all by weight.
Claim 8
Dependent Claim
44 words
A medium according to claim 6 wherein said copolymer accounts for 30 to 70%, said SO 3 M-containing polyurethane resin for 30 to 60%, said rubbery binder ingredients for 20 to 60%, and said polyisocyanate curing agent for 10 to 25%, all by 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) | 1990-04-20 | 1990-10-20 | 1991-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-20 | 1994-10-20 | 1995-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-20 | 1998-10-20 | 1999-04-21 | $7700.00 | Window Closed / Lapsed |