Patent US4770932A successfully refreshed from Google Patents.
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 04:11
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.
References Cited (Backward Citations)
DE2250383A1
Cited
GB1416946A
Cited
GB2080319A
Cited
US4423452A
Cited
JPS595429A
Cited
JPS595430A
Cited
JPS595423A
Cited
US4547425A
Cited
US4532178A
Cited
US4515856A
Cited
DE3328594A1
Cited
US4592952A
Cited
US4584243A
Cited
US4544601A
Cited
US4501795A
Cited
US4615930A
Cited
US4640863A
Cited
US4664973A
Cited
US4670333A
Cited
US4649072A
Cited
US4634627A
Cited
US4720413A
Cited
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 |