US4798755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1986-05-01
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Granted: 1989-01-17
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Expires: 2006-05-01
Abstract
Abstract A magnetic recording medium is disclosed, comprising a non-magnetic support having provided on one side thereof a magnetic recording layer comprising a binder having dispersed therein fine ferromagnetic particles and on the other side thereof a backing layer, wherein at least one of said magnetic layer and backing layer contains (1) a vinyl chloride resin having --SO 3 M (wherein M is Li, Na, or K) groups and epoxy groups, and (2) polyurethane as binders. The medium has reduced output variation and improved running durability.
Inventors
- 👤 Yasuyuki Yamada
- 👤 Hajime Miyatsuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:42
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; Y10T428/24; Y10T428/24355; Y10T428/24942; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/31504; Y10T428/31551; Y10T428/31609; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
126 words
A magnetic recording medium comprising a non-magnetic support having provided on one side thereof a magnetic layer comprising a binder having dispersed therein fine ferromagnetic particles and on the other side thereof a backing layer, wherein both said magnetic layer and said backing layer contain (1) a vinyl chloride resin having --SO 3 M groups, wherein M is selected from Li, Na, and K, and epoxy groups, and (2) polyurethane as binders, wherein said vinyl chloride resin contains from 0.1 to 2.0% by weight --SO 3 M groups, and from 0.2 to 10% by weight epoxy groups, based on the total weight of the resin; and wherein the weight of the fine ferromagnetic particles to the binder is in the range of from 100/13 to 100/45.
Claim 2
Dependent Claim
126 words
A magnetic recording medium comprising a non-magnetic support having provided on one side thereof a magnetic layer comprising a binder having dispersed therein fine ferromagnetic particles and on the other side thereof a backing layer, wherein both said magnetic layer and said backing layer contain (1) a vinyl chloride resin having --SO 3 M groups, wherein M is selected from Li, Na, and K, and epoxy groups, and (2) polyurethane as binders, wherein said vinyl chloride resin contains from 0.1 to 2.0% by weight --SO 3 M groups, and from 0.2 to 10% by weight epoxy groups, based on the total weight of the resin; and wherein the weight of the fine ferromagnetic particles to the binder is in the range of from 100/13 to 100/45.
Claim 3
Dependent Claim
35 words
A magnetic recording medium as in claim 1, wherein said vinyl chloride resin comprises from 80 to 90% by weight vinyl chloride and from 10 to 20% by weight of at least one copolymerizable monomer.
Claim 4
Dependent Claim
22 words
A magnetic recording medium as in claim 1, wherein said polyurethane has a number average molecular weight of from 20,000 to 100,000.
Claim 5
Dependent Claim
41 words
A magnetic recording medium as in claim 1, wherein said vinyl chloride resin contains from 0.2 to 1.5% by weight --SO 3 M groups, and from 0.7 to 5% by weight epoxy groups, based on the total weight of the resin.
Claim 6
Dependent Claim
19 words
A magnetic recording medium as in claim 1, wherein said --SO 3 M groups are --SO 3 Na groups.
Claim 7
Dependent Claim
30 words
A magnetic recording medium as in claim 1, wherein the weight ratio of the --SO 3 M-- and epoxy-containing vinyl chloride resin to the polyurethane is from 95/5 to 50/50.
Claim 8
Dependent Claim
24 words
A magnetic recording medium as in claim 1, wherein at least one of said magnetic layer and said backing layer further contains a polyisocyanate.
Claim 9
Dependent Claim
21 words
A magnetic recording medium as in claim 7, wherein said polyisocyanate has an average molecular weight of from 150 to 2,000.
Claim 10
Dependent Claim
34 words
A magnetic recording medium as in claim 7, wherein said polyisocyanate is present in an amount of from 5 to 100% by weight based on the total weight of the binder forming said layer.
Claim 11
Dependent Claim
43 words
A magnetic recording medium as in claim 1, wherein said backing layer has a center-line average roughness (Ra), at a cut-off value of 0.08 mm, of not more than 0.05 μm, and that of said magnetic layer is not more than 0.02 μm.
Claim 12
Dependent Claim
43 words
A magnetic recording medium as in claim 10, wherein said blocking layer has a center-line average roughness (Ra), at a cut-off value of 0.08 mm, of not more than 0.024 μm, and that of said magnetic layer is not more than 0.02 μm.
Claim 13
Dependent Claim
24 words
A magnetic recording medium as in claim 1, wherein said vinyl chloride resin has a number average molecular weight of from 15,000 to 60,000.
Claim 14
Dependent Claim
22 words
A magnetic recording medium as in claim 12, wherein said polyurethane has a number average molecular weight of from 20,000 to 100,000.
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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) | 1992-01-17 | 1992-07-18 | 1993-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-17 | 1996-07-18 | 1997-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-17 | 2000-07-18 | 2001-01-17 | $7700.00 | Window Closed / Lapsed |