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US4874633A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of producing magnetic recording medium

Assignee: Fujifilm Holdings Corp
•
Filing: 1986-10-17
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Granted: 1989-10-17
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Expires: 2006-10-17
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Abstract

Abstract A method of producing a magnetic recording medium comprises forming a magnetic layer by applying a magnetic film forming liquid onto a continuously running non-magnetic support, applying a magnetic field onto the magnetic film forming liquid before the magnetic film forming liquid has dried, and then drying the magnetic film forming liquid. A non-magnetic undercoating layer is formed on the support simultaneously with the step of forming the magnetic layer by simultaneously applying to the support a non-magnetic undercoating forming liquid and the magnetic film forming liquid. The magnetic field is applied before both the magnetic film forming liquid and non-magnetic undercoating forming liquid have dried.

Inventors

  • 👤 Kazunori Komatsu
  • 👤 Hiroshi Chikamasa
  • 👤 Tsunehiko Sato

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 22:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/842; G11B5/845; G11B5/62; G11B5/73; Y; Y10; Y10S; Y10S428/00; Y10S428/90

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 125 words
In a method for producing a magnetic recording medium by forming a magnetic layer by the steps of applying a magnetic film forming liquid onto a continuously running non-magnetic support, applying a magnetic field onto the magnetic film forming liquid before the magnetic film forming liquid has dried, and then drying the magnetic film forming liquid, the improvement comprising: forming a non-magnetic undercoating layer on the support simultaneously with forming the magnetic layer by simultaneously applying to the support a non-magnetic undercoating forming liquid and the magnetic film forming liquid, and applying the magnetic field before both the magnetic film forming liquid and non-magnetic undercoating forming liquid have dried, and wherein the magnetic layer is formed with a thickness of no more than 2 microns.
Claim 2
Dependent Claim 125 words
In a method for producing a magnetic recording medium by forming a magnetic layer by the steps of applying a magnetic film forming liquid onto a continuously running non-magnetic support, applying a magnetic field onto the magnetic film forming liquid before the magnetic film forming liquid has dried, and then drying the magnetic film forming liquid, the improvement comprising: forming a non-magnetic undercoating layer on the support simultaneously with forming the magnetic layer by simultaneously applying to the support a non-magnetic undercoating forming liquid and the magnetic film forming liquid, and applying the magnetic field before both the magnetic film forming liquid and non-magnetic undercoating forming liquid have dried, and wherein the magnetic layer is formed with a thickness of no more than 2 microns.
Claim 3
Dependent Claim 18 words
Method according to claim 1, wherein the magnetic layer is formed with a thickness of about 1 micron.

References Cited (Backward Citations)

GB1416200A Cited
US3920862A Cited
JPS53144705A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-10-16 1993-04-17 1993-10-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-10-16 1997-04-17 1997-10-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-10-16 2001-04-17 2001-10-17 $7700.00 Window Closed / Lapsed

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