Patent US4436786A successfully refreshed from Google Patents.
US4436786A
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US
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Magnetic recording medium
Assignee: TDK Corp
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Filing: 1982-03-31
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Granted: 1984-03-13
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Expires: 2002-03-31
Abstract
Abstract A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a higher fatty having a melting point of 44° C. or more into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH 3 , R' is CH 3 , C 6 H 5 or F and n is a number which determines a viscosity thereof. Such higher fatty acid is selected from lauric acid, myristic acid, palmitic acid, stearic acid, arachic acid, behenic acid and the like.
Inventors
- 👤 Takehisa Ohkawa
- 👤 Kuniichi Yoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:06
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
84 words
A magnetic recording medium comprising a base material and a magnetic coating layer thereon, said magnetic coating layer containing a binder, a highly viscous silicone oil having a viscosity of at least 100,000 centistokes and a higher fatty acid having a melting point of at least 44° C., said silicone oil in an amount of about 0.2% to about 2.0% by weight of said binder and said higher fatty acid in an amount of about 0.5% to about 4.0% by weight of said binder.
Claim 2
Dependent Claim
84 words
A magnetic recording medium comprising a base material and a magnetic coating layer thereon, said magnetic coating layer containing a binder, a highly viscous silicone oil having a viscosity of at least 100,000 centistokes and a higher fatty acid having a melting point of at least 44° C., said silicone oil in an amount of about 0.2% to about 2.0% by weight of said binder and said higher fatty acid in an amount of about 0.5% to about 4.0% by weight of said binder.
Claim 3
Dependent Claim
117 words
A magnetic recording medium comprising a base material and a magnetic coating layer thereon, said magnetic coating layer containing a binder, a highly viscous silicone oil having a viscosity of at least 100,000 centistokes and a higher fatty acid having a melting point of at least 44° C., said silicone oil being represented by the general formula: ##STR3## wherein R is CH 3 , R' is CH 3 , C 6 H 5 or F and n is a number which determines the viscosity thereof, said silicone oil in an amount of 0.2% to 2.0% by weight of said binder and said higher fatty acid in an amount of 0.5% to 4.0% by weight of said binder.
Claim 4
Dependent Claim
117 words
A magnetic recording medium comprising a base material and a magnetic coating layer thereon, said magnetic coating layer containing a binder, a highly viscous silicone oil having a viscosity of at least 100,000 centistokes and a higher fatty acid having a melting point of at least 44° C., said silicone oil being represented by the general formula: ##STR3## wherein R is CH 3 , R' is CH 3 , C 6 H 5 or F and n is a number which determines the viscosity thereof, said silicone oil in an amount of 0.2% to 2.0% by weight of said binder and said higher fatty acid in an amount of 0.5% to 4.0% by weight of said binder.
Claim 5
Dependent Claim
21 words
A magnetic recording medium as defined in claim 1 or 2 wherein the silicone oil has a viscosity of 300,000 centistokes.
Claim 6
Dependent Claim
23 words
A magnetic recording medium as defined in claim 2 wherein the silicone oil is a dimethyl polysiloxane having a viscosity of 100,000 centistokes.
Claim 7
Dependent Claim
23 words
A magnetic recording medium as defined in claim 2 wherein the silicone oil is a dimethyl polysiloxane having a viscosity of 300,000 centistokes.
Claim 8
Dependent Claim
32 words
A magnetic recording medium as defined in claim 1 wherein the higher fatty acid is selected from lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid and the like.
Claim 9
Dependent Claim
17 words
A magnetic recording medium as defined in claim 6 wherein the higher fatty acid is palmitic acid.
Claim 10
Dependent Claim
26 words
A magnetic recording medium as defined in claim 1 wherein the binder is a combination of a vinyl chloride/vinyl acetate copolymer resin with a polyurethane resin.
Claim 11
Dependent Claim
18 words
A magnetic recording medium as defined in claim 1 wherein the base material is a flexible plastics film.
Claim 12
Dependent Claim
30 words
A magnetic recording medium as defined in claim 1 wherein the magnetic coating layer further contains an antistatic agent and a dispersing agent which are conventionally used in the art.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-13 | 1987-09-12 | 1988-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-13 | 1991-09-12 | 1992-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-13 | 1995-09-12 | 1996-03-13 | $7700.00 | Window Closed / Lapsed |