US4615949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1985-07-12
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Granted: 1986-10-07
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Expires: 2005-07-12
Abstract
Abstract A magnetic recording medium comprises a magnetic coating material, or a dispersion of magnetic particles in a resinous binder, and a base to which the coating material is solidly applied, the resinous binder comprising as its ingredients a copolymer composed of vinyl chloride, vinylidene 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 at least 0.2, a polyurethane resin having in its molecule a --SO 3 M group wherein M represents an alkali metal atom, and a polyisocyanate.
Inventors
- 👤 Kuniichi Yoda
- 👤 Yuji Ishihara
- 👤 Hitoshi Azegami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:41
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; G11B5/7022; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/31504; Y10T428/31551; Y10T428/31609; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
98 words
A magnetic recording medium comprising a magnetic coating material, or a dispersion of magnetic particles in a resinous binder, and a base to which the coating material is solidly applied, said resinous binder comprising as ingredients thereof a copolymer composed of vinyl chloride, vinylidene 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 at least 0.2, a polyurethane resin having in the molecule thereof a --SO 3 M group wherein M represents an alkali metal atom, and a polyisocyanate.
Claim 2
Dependent Claim
98 words
A magnetic recording medium comprising a magnetic coating material, or a dispersion of magnetic particles in a resinous binder, and a base to which the coating material is solidly applied, said resinous binder comprising as ingredients thereof a copolymer composed of vinyl chloride, vinylidene 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 at least 0.2, a polyurethane resin having in the molecule thereof a --SO 3 M group wherein M represents an alkali metal atom, and a polyisocyanate.
Claim 3
Dependent Claim
22 words
A magnetic recording medium according to claim 1 wherein the vinyl alkylcarboxylate is selected from vinyl acetate, vinyl propionate and vinyl Versatate.
Claim 4
Dependent Claim
15 words
A magnetic recording medium according to claim 2 wherein the vinyl alkylcarboxylate is vinyl acetate.
Claim 5
Dependent Claim
33 words
A magnetic recording medium according to claim 1 wherein another monomer copolymerizable with vinyl chloride is selected from maleic acid, fumaric acid, acrylic acid, methacrylic acid, an ester thereof, and a combination thereof.
Claim 6
Dependent Claim
18 words
A magnetic recording medium according to claim 4 wherein another monomer copolymerizable with vinyl chloride is maleic acid.
Claim 7
Dependent Claim
26 words
A magnetic recording medium according to claim 1 wherein the SO 3 M group of the polyurethane resin is --SO 3 Na or --SO 3 K.
Claim 8
Dependent Claim
42 words
A magnetic recording medium according to claim 1 wherein the proportion of the SO 3 M group, wherein M represents an alkali metal atom, contained in the polyurethane resin is in the range of about 10 to 1000 g equivalent/10 4 g.
Claim 9
Dependent Claim
57 words
A magnetic recording medium according to claim 1 wherein the copolymer comprises, all by weight on the basis thereof, 50 to 85% of vinyl chloride, 5 to 40% of vinylidene chloride, 5 to 40% of a vinyl alkylcarboxylate, 1.0 to 5.0% of another monomer copolymerizable with vinyl chloride, and the remainder substantially of a saponified vinyl alkylcarboxylate.
Claim 10
Dependent Claim
48 words
A medium according to claim 1 wherein, on the basis of the total resin weight in the resinous binder, the SO 3 M group-containing polyurethane resin is used in the amount of 20 to 80%, the polyisocyanate 5 to 30%, and the copolymer the remainder, all be weight.
Claim 11
Dependent Claim
37 words
A medium according to claim 9 wherein the SO 3 M group-containing polyurethane resin is used in an amount of 30 to 70%, the polyisocyanate 10 to 25%, and the copolymer 70 to 30%, all by weight.
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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) | 1989-10-06 | 1990-04-07 | 1990-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-06 | 1994-04-07 | 1994-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-06 | 1998-04-07 | 1998-10-07 | $7700.00 | Window Closed / Lapsed |