US4443490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Sony Corp
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Filing: 1982-11-18
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Granted: 1984-04-17
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Expires: 2002-11-18
Abstract
Abstract A magnetic recording medium carrying a magnetic layer thereon, the magnetic layer primarily composed of binder and magnetic powder, wherein the binder is composed of an acrylic compound having a plurality of unsaturated bonds in its molecule and a thermoplastic resin in a weight ratio of 80:20 to 20:80, and is hardened under irradiation.
Inventors
- 👤 Kaoru Nakajima
- 👤 Kunio Kobayashi
- 👤 Yoshiaki Hisagen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7023; G11B5/7026
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
108 words
A method of manufacturing a magnetic recording medium which comprises: coating a magnetic paint composed of magnetic powder and a binder on a non-magnetic substrate to form a coating layer, said binder containing an acrylic compound having at least two unsaturated bonds per molecule and a thermoplastic resin in a weight ratio of 80:20 to 20:80, preliminarily irradiating the coating layer with an ionizing radiation at a dose amount of 0.1 to 3 Mrad; subjecting the coating layer to a calender treatment; and irradiating the calendered coating layer with an ionizing radiation at a dose amount of from 1 to 10 Mrad to fully cure the coating layer.
Claim 2
Independent Claim
108 words
A method of manufacturing a magnetic recording medium which comprises: coating a magnetic paint composed of magnetic powder and a binder on a non-magnetic substrate to form a coating layer, said binder containing an acrylic compound having at least two unsaturated bonds per molecule and a thermoplastic resin in a weight ratio of 80:20 to 20:80, preliminarily irradiating the coating layer with an ionizing radiation at a dose amount of 0.1 to 3 Mrad; subjecting the coating layer to a calender treatment; and irradiating the calendered coating layer with an ionizing radiation at a dose amount of from 1 to 10 Mrad to fully cure the coating layer.
Claim 3
Dependent Claim
21 words
A method according to claim 1 wherein: the molecular weight of said acrylic compound is 100 to 10,000 per double bond.
Claim 4
Dependent Claim
21 words
A method according to claim 1 wherein: the molecular weight of said acrylic compound is 200 to 2,000 per double bond.
Claim 5
Dependent Claim
18 words
A method according to claim 1 wherein: said thermoplastic resin is a thermoplastic polyurethane or a thermoplastic polyester.
Claim 6
Dependent Claim
19 words
A method according to claim 1 in which: the irradiating is carried out by means of an electron beam.
Claim 7
Dependent Claim
22 words
A method according to claim 1 in which: the irradiating is carried out with a radiation energy of at least 100 keV.
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) | 1987-04-17 | 1987-10-17 | 1988-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-17 | 1991-10-17 | 1992-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-17 | 1995-10-17 | 1996-04-17 | $7700.00 | Window Closed / Lapsed |