Patent US3881046A successfully refreshed from Google Patents.
US3881046A
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1973-06-21
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Granted: 1975-04-29
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Expires: 1993-06-21
Abstract
Abstract A magnetic recording medium for use in recording shortwavelength which is excellent in easiness of marking by a black or dark color marking material, in easiness and validity of discrimination of the mark, and in antistatic effect can be prepared by providing a magnetizable layer on one side of a nonmagnetizable plastic film and providing a layer having a surface electric resistance of below 1 X 109 ohm on the opposite side and further, a white or light color layer thereon.
Inventors
- 👤 Goro Akashi
- 👤 Masaaki Fujiyama
- 👤 Yasuyuki Yama
- 👤 Tokuaki Miyake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:57
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/31504; Y10T428/31551; Y10T428/31609; Y10T428/31786; Y10T428/31797
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
73 words
A MAGNETIC RECORDING MEDIUM FOR USE IN RECORDING SHORTWAVELENGTH COMPRISING A NON-MAGNETIZABLE PLASTIC FILM SUPPORT HAVING A MAGNETIZABLE LAYER ON ONE SIDE THEREOF AND, ON THE OTHER SIDE THEREOF, A FIRST LAYER HAVING A SURFACE ELECTRIC RESISTANCE OF BELOW 1 X 10**9 OHM AND A SECOND LAYER COMPRISING A PIGMENT THAT CAN BE EASILY MARKED BY A MARKING MATERIAL AND PROVIDES EASY VISUAL DISCRIMINATIONN OF A MARK PRODUCED THEREON BY SAID MARKING MATERIAL.
Claim 2
Dependent Claim
73 words
A MAGNETIC RECORDING MEDIUM FOR USE IN RECORDING SHORTWAVELENGTH COMPRISING A NON-MAGNETIZABLE PLASTIC FILM SUPPORT HAVING A MAGNETIZABLE LAYER ON ONE SIDE THEREOF AND, ON THE OTHER SIDE THEREOF, A FIRST LAYER HAVING A SURFACE ELECTRIC RESISTANCE OF BELOW 1 X 10**9 OHM AND A SECOND LAYER COMPRISING A PIGMENT THAT CAN BE EASILY MARKED BY A MARKING MATERIAL AND PROVIDES EASY VISUAL DISCRIMINATIONN OF A MARK PRODUCED THEREON BY SAID MARKING MATERIAL.
Claim 3
Dependent Claim
38 words
The magnetic recording medium of claim 1, wherein said second layer comprising a pigment can be easily marked by a black marking material and provides easy visual discrimination of a mark produced thereon by a black marking material.
Claim 4
Dependent Claim
20 words
The magnetic recording medium of claim 1, wherein said first layer comprises an electrically conductive substance dispersed in a binder.
Claim 5
Dependent Claim
20 words
The magnetic recording medium of claim 3, wherein said electrically conductive substance comprises carbon black, graphite, copper, aluminum or silver.
Claim 6
Dependent Claim
18 words
The magnetic recording medium of claim 1, wherein said second layer comprises yellow pigment dispersed in a binder.
Claim 7
Dependent Claim
19 words
The magnetic recording medium of claim 5, wherein said colored pigment is lead yellow, zinc yellow, or cadmium yellow.
Claim 8
Dependent Claim
19 words
The magnetic recording medium of claim 1, wherein said second layer comprises a white pigment dispersed in a binder.
Claim 9
Dependent Claim
30 words
The magnetic recording medium of claim 7, wherein said pigment is white lead, zinc white, lithopone, titanium white, barite, barium sulfate, limestone, calcium carbonate, chalk, aluminum hydroxide, talc, or kaolin.
Claim 10
Dependent Claim
118 words
A magnetic recording medium for use in recording short-wavelength consisting essentially of a non-magnetizable plastic film support having a magnetizable layer on one side thereof, and on the other side thereof, a first layer having a surface electric resistance of below 1 X 109 ohm and a second layer coated onto said first layer consisting essentially of a pigment dispersed in a binder, said second layer can be easily marked by a marking material and provides easy visual discrimination of a mark produced thereon by said marking material, said magnetizable layer having a thickness of from 4 to 150 Mu and said first layer consisting essentially of a powder of an electrically conductive material dispersed in a binder.
Claim 11
Dependent Claim
118 words
A magnetic recording medium for use in recording short-wavelength consisting essentially of a non-magnetizable plastic film support having a magnetizable layer on one side thereof, and on the other side thereof, a first layer having a surface electric resistance of below 1 X 109 ohm and a second layer coated onto said first layer consisting essentially of a pigment dispersed in a binder, said second layer can be easily marked by a marking material and provides easy visual discrimination of a mark produced thereon by said marking material, said magnetizable layer having a thickness of from 4 to 150 Mu and said first layer consisting essentially of a powder of an electrically conductive material dispersed in a binder.
Claim 12
Dependent Claim
104 words
The magnetic recording medium of claim 10, wherein said powder of said electrically conductive material has a particle size of from 0.01 to 10 Mu , wherein said first layer has a thickness of from 0.3 to 5 Mu and wherein the weight ratio of said electrically conductive powder to said binder is from 10:1 to 1:2, wherein said pigment has a particle size of from 0.005 to 20 Mu , wherein the thickness of said second layer varies from 0.5 to 5 Mu and wherein the weight ratio of said pigment to said binder in said second layer varies from 10:1 to 1:2.
Claim 13
Dependent Claim
23 words
The magnetic recording medium of claim 11, wherein said magnetizable layer comprises a fine powder of a ferromagnetic material dispersed in said binder.
Claim 14
Dependent Claim
16 words
The magnetic recording medium of claim 11, wherein said magnetizable layer comprises a plated ferromagnetic film.
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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) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |