Patent US4582759A successfully refreshed from Google Patents.
US4582759A
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Magnetic recording medium and process for producing same
Assignee: TDK Corp
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Filing: 1984-11-01
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Granted: 1986-04-15
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Expires: 2004-11-01
Abstract
Abstract A magnetic recording medium having a magnetic layer which is formed by dispersing a magnetic powder and further an abrasive when necessary into a binder containing a sugar alcohol. The magnetic recording medium has excellent glossiness, squareness ratio and other surface properties due to the improvement of dispersibility of the magnetic powder and/or an abrasive when necessary.
Inventors
- 👤 Hiroshi Ota
- 👤 Kinji Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:02
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/04; C08K5/05; C08K3/00; C08K3/18; C08K3/20; C08K3/22; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
26 words
A magnetic recording medium having a magnetic layer which includes a magnetic powder dispersed in a binder, comprising a sugar alcohol adsorbed onto the magnetic powder.
Claim 2
Dependent Claim
26 words
A magnetic recording medium having a magnetic layer which includes a magnetic powder dispersed in a binder, comprising a sugar alcohol adsorbed onto the magnetic powder.
Claim 3
Dependent Claim
14 words
A magnetic recording medium according to claim 1, which further comprises an abrasive therein.
Claim 4
Dependent Claim
37 words
A magnetic recording medium according to claim 1 or 2 wherein the sugar alcohol is contained in an amount of about 0.5 to about 10% by weight on the basis of the magnetic powder and abrasive weight.
Claim 5
Dependent Claim
37 words
A magnetic recording medium according to claim 1 or 2 wherein the sugar alcohol is contained in an amount of about 0.7 to about 5% by weight on the basis of the magnetic powder and abrasive weight.
Claim 6
Dependent Claim
29 words
A magnetic recording medium according to claim 1 or 2 wherein the sugar alcohol is selected from the group consisting of sorbitol, mannitol or dulcitol or a mixture thereof.
Claim 7
Dependent Claim
50 words
A process for producing a magnetic recording medium having a magnetic layer formed of a magnetic powder and an abrasive where necessary, dispersed in a binder, comprising thoroughly mixing a sugar alcohol with the magnetic powder and the abrasive where necessary and then mixing the resulting mixture with the binder.
Claim 8
Dependent Claim
50 words
A process for producing a magnetic recording medium having a magnetic layer formed of a magnetic powder and an abrasive where necessary, dispersed in a binder, comprising thoroughly mixing a sugar alcohol with the magnetic powder and the abrasive where necessary and then mixing the resulting mixture with the binder.
Claim 9
Dependent Claim
20 words
A process according to claim 6 wherein the sugar alcohol is in the form of a solution in a solvent.
Claim 10
Dependent Claim
13 words
A process according to claim 7 wherein the solvent is water or ethanol.
Claim 11
Dependent Claim
27 words
A process according to claim 6 or 7 wherein the sugar alcohol is selected from the group consisting of sorbitol, mannitol or dulcitol or a mixture thereof.
Claim 12
Dependent Claim
26 words
A process according to claim 7 or 8 wherein a concentration of sugar alcohol in the solvent ranges from about 2 to about 30% by weight.
Claim 13
Dependent Claim
26 words
A process according to claim 7 or 8 wherein a concentration of sugar alcohol in the solvent ranges from about 5 to about 20% by weight.
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) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |