Patent US4716077A successfully refreshed from Google Patents.
US4716077A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1986-07-11
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Granted: 1987-12-29
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Expires: 2006-07-11
Abstract
Abstract A magnetic recording medium is described, comprising a non-magnetic support and a magnetic layer, said magnetic layer containing as a binder at least one compound selected from each of compound groups (A) and (B) that has been exposed to radiation, wherein (A) is polyvinyl chloride type compounds containing at least one polar group and at least one carbon-carbon unsaturated bond per molecule; and (B) is polyurethane type compounds containing at least one --CO 2 H group and at lease one carbon-carbon unsaturated bond per molecule.
Inventors
- 👤 Tsutomu Okita
- 👤 Hiroshi Hashimoto
- 👤 Masashi Aonuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:48
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; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/31504; Y10T428/31551; Y10T428/31609; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
140 words
A magnetic recording medium comprising a non-magnetic support and a magnetic layer, said magnetic layer containing as a binder at least one compound selected from each of the compound groups (A) and (B) that has been exposed to radiation, wherein (A) is polyvinyl chloride type compounds having a molecular weight of 5,000 to 50,000 containing at least on CO 2 H group and at least one carbon-carbon unsaturated bond per molecule and having an acid value of from 1 to 30; and (B) is polyurethane type compounds having a molecular weight of 1,000 to 100,000 containing at least one --CO 2 H group and at least one carbon-carbon unasturated bond per molecule and having an acid value of from 1 to 30, wherein the mixing ratio of compound(s) (A) and compound(s) (B) is from 20/80 to 90/10 parts by weight.
Claim 2
Dependent Claim
140 words
A magnetic recording medium comprising a non-magnetic support and a magnetic layer, said magnetic layer containing as a binder at least one compound selected from each of the compound groups (A) and (B) that has been exposed to radiation, wherein (A) is polyvinyl chloride type compounds having a molecular weight of 5,000 to 50,000 containing at least on CO 2 H group and at least one carbon-carbon unsaturated bond per molecule and having an acid value of from 1 to 30; and (B) is polyurethane type compounds having a molecular weight of 1,000 to 100,000 containing at least one --CO 2 H group and at least one carbon-carbon unasturated bond per molecule and having an acid value of from 1 to 30, wherein the mixing ratio of compound(s) (A) and compound(s) (B) is from 20/80 to 90/10 parts by weight.
Claim 3
Dependent Claim
26 words
A magnetic recording medium as in claim 1, wherein the mixing ratio of compound(s) (A) and compound(s) (B) is from 30/70 to 80/20 parts by weight.
Claim 4
Dependent Claim
15 words
A magnetic recording medium as in claim 1, wherein (B) is polyurethane acrylate or methacrylate.
Claim 5
Dependent Claim
37 words
A magnetic recording medium as in claim 1, wherein ferromagnetic particles are used in the magnetic layer, and said particles are ferromagnetic alloy particles having a BET specific surface area of 30 m 2 /g or more.
Claim 6
Dependent Claim
17 words
A magnetic recording medium as in claim 1, wherein the acid value is from 3 to 20.
Claim 7
Dependent Claim
17 words
A magnetic recording medium as in claim 1, wherein the acid value is from 5 to 15.
Claim 8
Dependent Claim
23 words
A magnetic recording medium as in claim 1, wherein the average content of carbon-carbon unsaturated bonds is from 1.5 to 20 per molecule.
Claim 9
Dependent Claim
23 words
A magnetic recording medium as in claim 1, wherein the average content of carbon-carbon unsaturated bonds is from 2 to 15 per molecule.
Claim 10
Dependent Claim
23 words
A magnetic recording medium as in claim 5, wherein the average content of carbon-carbon unsaturated bonds is from 1.5 to 20 per molecule.
Claim 11
Dependent Claim
23 words
A magnetic recording medium as in claim 6, wherein the average content of carbon-carbon unsaturated bonds is from 2 to 15 per molecule.
Claim 12
Dependent Claim
17 words
A magnetic recording medium as in claim 3, wherein the acid value is from 3 to 20.
Claim 13
Dependent Claim
17 words
A magnetic recording medium as in claim 3, wherein the acid value is from 5 to 15.
Claim 14
Dependent Claim
25 words
A magnetic recording medium as in claim 3, wherein the average content of acryloyl or methacryloyl groups is from 1.5 to 10 groups per molecule.
Claim 15
Dependent Claim
25 words
A magnetic recording medium as in claim 3, wherein the average content of acryloyl or methacryloyl groups is from 2 to 8 groups per molecule.
Claim 16
Dependent Claim
21 words
A magnetic recording medium as in claim 4, wherein the BET specific surface area is 45 m 2 /g or more.
Claim 17
Dependent Claim
23 words
A magnetic recording medium as in claim 1, wherein the polyvinyl chloride type compound has a molecular weight of from 10,000 to 30,000.
Claim 18
Dependent Claim
22 words
A magnetic recording medium as in claim 1, wherein the polyurethane type compound has a molecular weight of from 3,000 to 30,000.
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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) | 1990-12-28 | 1991-06-29 | 1991-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-28 | 1995-06-29 | 1995-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-28 | 1999-06-29 | 1999-12-29 | $7700.00 | Window Closed / Lapsed |