US4409300A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1982-03-31
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Granted: 1983-10-11
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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 sorbitan fatty acid ester 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 sorbitan fatty acid ester is selected from sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, sorbitan tristearate, sorbitan monooleate and the like.
Inventors
- 👤 Takehisa Ohkawa
- 👤 Kuniichi Yoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:56
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; G11B5/702; G11B5/7028; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
137 words
A magnetic recording medium comprising a base material and a magnetic coating layer thereon comprised of a magnetic material dispersed in a binder, characterized in that the magnetic coating layer contains a highly viscous silicone oil having a viscosity of 100,000 centistokes or more in combination with a sorbitan fatty acid ester, 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 of said silicone oil; and wherein said silicone oil is used in an amount of from 0.2 to 2 percent by weight, and the sorbitan fatty acid ester is used in an amount of from 0.5 to 4 percent by weight, each based on the weight of the binder.
Claim 2
Dependent Claim
137 words
A magnetic recording medium comprising a base material and a magnetic coating layer thereon comprised of a magnetic material dispersed in a binder, characterized in that the magnetic coating layer contains a highly viscous silicone oil having a viscosity of 100,000 centistokes or more in combination with a sorbitan fatty acid ester, 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 of said silicone oil; and wherein said silicone oil is used in an amount of from 0.2 to 2 percent by weight, and the sorbitan fatty acid ester is used in an amount of from 0.5 to 4 percent by weight, each based on the weight of the binder.
Claim 3
Dependent Claim
19 words
A magnetic recording medium as defined in claim 1 wherein the silicone oil has a viscosity of 300,000 centistokes.
Claim 4
Dependent Claim
23 words
A magnetic recording medium as defined in claim 1 wherein the silicone oil is a dimethyl polysiloxane having a viscosity of 100,000 centistokes.
Claim 5
Dependent Claim
23 words
A magnetic recording medium as defined in claim 1 wherein the silicone oil is a dimethyl polysiloxane having a viscosity of 300,000 centistokes.
Claim 6
Dependent Claim
31 words
A magnetic recording medium as defined in claim 1 wherein the sorbitan fatty acid ester is selected from sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, sorbitan tristearate, sorbitan monooleate and the like.
Claim 7
Dependent Claim
18 words
The magnetic recording medium as defined in claim 5 wherein the sorbitan fatty acid ester is sorbitan monostearate.
Claim 8
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 9
Dependent Claim
18 words
A magnetic recording medium as defined in claim 1 wherein the base material is a flexible plastics film.
Claim 10
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) | 1986-10-10 | 1987-04-11 | 1987-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-10 | 1991-04-11 | 1991-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-10 | 1995-04-11 | 1995-10-11 | $7700.00 | Window Closed / Lapsed |