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US4307154A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetic recording medium

Assignee: TDK Corp
•
Filing: 1979-11-09
•
Granted: 1981-12-22
•
Expires: 1999-11-09
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Abstract

Abstract A magnetic recording medium having improved electromagnetic conversion characteristics and physical properties prepared by using a three-component binder consisting of a polyurethane resin, a phenoxy resin and a vinyl chloride-vinylidene chloride resin.

Inventors

  • 👤 Akihiko Hosaka
  • 👤 Kazushi Tanaka

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 21:43
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; Y10T428/31511; Y10T428/31551; Y10T428/31565; Y10T428/31573; Y10T428/3158; Y10T428/31609

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 69 words
A magnetic recording medium comprising a base support and a layer of a magnetic coating material on said base support, said magnetic coating material comprising a magnetic material dispersed in a binder containing three resin components, namely from 30 to 70% of a polyurethane resin, from 15 to 45% of a phenoxy resin and from 5 to 45% of a vinyl chloride-vinylidene chloride resin, all percentages being by weight.
Claim 2
Dependent Claim 69 words
A magnetic recording medium comprising a base support and a layer of a magnetic coating material on said base support, said magnetic coating material comprising a magnetic material dispersed in a binder containing three resin components, namely from 30 to 70% of a polyurethane resin, from 15 to 45% of a phenoxy resin and from 5 to 45% of a vinyl chloride-vinylidene chloride resin, all percentages being by weight.
Claim 3
Dependent Claim 20 words
A magnetic recording medium according to claim 1, wherein said powdered magnetic material is Co-doped γ-Fe 2 O 3 .
Claim 4
Dependent Claim 16 words
A magnetic recording medium according to claim 1, wherein said base support is a polyester film.

References Cited (Backward Citations)

US3247017A Cited
US3320090A Cited
US3740266A Cited
US3689317A Cited
US3650828A Cited
US3840400A Cited
JPS5110914A Cited
US3911196A Cited
SU661600A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-12-21 1985-06-22 1985-12-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-12-21 1989-06-22 1989-12-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-12-21 1993-06-22 1993-12-22 $7700.00 Window Closed / Lapsed

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