US4770932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium having an improved back coat layer
Assignee: Victor Company of Japan Ltd
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Filing: 1986-05-28
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Granted: 1988-09-13
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Expires: 2006-05-28
Abstract
Abstract A magnetic recording medium which comprises a non-magnetic substrate, a magnetic recording layer formed on one side of said substrate, and a back coat layer formed on the other side of the substrate. The back coat layer is made of a composition which comprises particles of carbon black, titanium monoxide or a mixture thereof having an average size not larger than 1 micrometer and a resin binder dispersing the particles therein. The particles are individually precoated with an isocyanate compound. When coated titanium monoxide particles are used singly, non-coated carbon black is effectively used in combination.
Inventors
- 👤 Yukio Matsumoto
- 👤 Hiroshi Togashi
- 👤 Hiroshi Ogino
- 👤 Kumiko Ojima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:28
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/735; G11B5/7356; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998; Y10T428/31504; Y10T428/31551; Y10T428/31609
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
112 words
In a magnetic recording medium which comprises a non-magnetic substrate, a magnetic recording layer formed on one side of said substrate, and a back coat layer formed on the other side of said substrate, the improvement characterized in that said back coat layer is made of a composition which comprises 25 to 400 parts by weight of particles of carbon black, titanium monoxide or a mixture thereof having an average size not larger than 1 micrometer, the individual particles being precoated with an isocyanate compound in an amount of from 1 to 100 weight percent of the particles, and 100 parts by weight of a resin binder dispersing the precoated particles therein.
Claim 2
Dependent Claim
112 words
In a magnetic recording medium which comprises a non-magnetic substrate, a magnetic recording layer formed on one side of said substrate, and a back coat layer formed on the other side of said substrate, the improvement characterized in that said back coat layer is made of a composition which comprises 25 to 400 parts by weight of particles of carbon black, titanium monoxide or a mixture thereof having an average size not larger than 1 micrometer, the individual particles being precoated with an isocyanate compound in an amount of from 1 to 100 weight percent of the particles, and 100 parts by weight of a resin binder dispersing the precoated particles therein.
Claim 3
Dependent Claim
46 words
A magnetic recording medium according to claim 1, wherein said particles are particles of carbon black having an average size of from 0.01 to 0.05 micrometers and a specific surface area of not larger than 800 m 2 /g when determined by the BET absorption method.
Claim 4
Dependent Claim
25 words
A magnetic recording medium according to claim 1, wherein the amount of the isocyanate compound coating ranges from 5 to 40 wt% of the particles.
Claim 5
Dependent Claim
16 words
A magnetic recording medium according to claim 1, wherein said particles are particles of titanium monoxide.
Claim 6
Dependent Claim
22 words
A magnetic recording medium according to claim 1, wherein said particles are particles of a mixture of carbon black and titanium monoxide.
Claim 7
Dependent Claim
143 words
In a magnetic recording medium which comprises a non-magnetic substrate, a magnetic recording layer formed on one side of said substrate, and a back coat layer formed on the other side of said substrate, the improvement characterized in that said back coat layer is made of a composition which comprises 25 to 400 parts by weight of carbon black particles having an average size not larger than 1 micrometer, titanium monoxide particles having an average size not larger than 1 micrometer and individually precoated with an isocyanate compound in an amount of from 1 to 100 weight percent of said titanium monoxide particles, said titanium monoxide particles being used in an amount of from 0.5 to 70 wt% of said carbon black particles, and 100 parts by weight of a resin binder dispersing the carbon black particles and the precoated titanium monoxide particles.
Claim 8
Dependent Claim
143 words
In a magnetic recording medium which comprises a non-magnetic substrate, a magnetic recording layer formed on one side of said substrate, and a back coat layer formed on the other side of said substrate, the improvement characterized in that said back coat layer is made of a composition which comprises 25 to 400 parts by weight of carbon black particles having an average size not larger than 1 micrometer, titanium monoxide particles having an average size not larger than 1 micrometer and individually precoated with an isocyanate compound in an amount of from 1 to 100 weight percent of said titanium monoxide particles, said titanium monoxide particles being used in an amount of from 0.5 to 70 wt% of said carbon black particles, and 100 parts by weight of a resin binder dispersing the carbon black particles and the precoated titanium monoxide particles.
Claim 9
Dependent Claim
26 words
A magnetic recording medium according to claim 6, wherein the amount of the isocyanate compound ranges from 5 to 40 wt% of the titanium monoxide particles.
Claim 10
Dependent Claim
31 words
A magnetic recording medium according to claim 6, wherein the amount of the coated titanium monoxide particles is in the range of from 10 to 40 wt% of the carbon black.
Claim 11
Dependent Claim
22 words
A magnetic recording medium according to claim 6, wherein the back coat layer has a thickness of from 0.3 to 4 micrometers.
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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) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |