Patent US2197214A successfully refreshed from Google Patents.
US4497864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Holdings Corp
•
Filing: 1983-07-06
•
Granted: 1985-02-05
•
Expires: 2003-07-06
Abstract
Abstract A magnetic recording medium is disclosed. The medium is comprised of a support base having coated thereon a magnetic layer comprised of ferromagnetic particles dispersed in a binder and further comprised of at least one anhydrosorbitol di- and/or tetra-fatty acid non-hydroxy ester. By including the particularly disclosed fatty acid non-hydroxy ester the running properties of the magnetic recording medium are greatly improved.
Inventors
- 👤 Katsumi Ryoke
- 👤 Nobutaka Yamaguchi
- 👤 Takashi Yoneyama
- 👤 Eiichi Tadokoro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:41
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; Y10T428/25; Y10T428/26; Y10T428/266; Y10T428/27
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
84 words
A magnetic recording medium comprising a support base having coated thereon a magnetic layer comprised of ferromagnetic powders dispersed in a binder, and at least one of anhydrosorbitol fatty acid non-hydroxy ester compounds represented by the formula selected from the group consisting of (I), (II) and (III): ##STR4## and ##STR5## wherein R 1 , R 2 , R 3 and R 4 each represents a saturated alkyl group having 1 to 22 carbon atoms or an alkylene group having 2 to 22 carbon atoms.
Claim 2
Dependent Claim
84 words
A magnetic recording medium comprising a support base having coated thereon a magnetic layer comprised of ferromagnetic powders dispersed in a binder, and at least one of anhydrosorbitol fatty acid non-hydroxy ester compounds represented by the formula selected from the group consisting of (I), (II) and (III): ##STR4## and ##STR5## wherein R 1 , R 2 , R 3 and R 4 each represents a saturated alkyl group having 1 to 22 carbon atoms or an alkylene group having 2 to 22 carbon atoms.
Claim 3
Dependent Claim
67 words
A magnetic recording medium as claimed in claim 1, wherein the ferromagnetic powder is present in an amount of 50 to 2,000 parts by weight per 100 parts by weight of the binder and further wherein the anhydrosorbitol fatty acid non-hydroxy ester compound is present in an amount in the range of 0.05 to 20 parts by weight per 100 parts by weight of the ferromagnetic powder.
Claim 4
Dependent Claim
41 words
A magnetic recording medium as claimed in claim 2, wherein the anhydrosorbitol fatty acid non-hydroxy ester compound is present in an amount in the range of 0.1 to 10 parts by weight per 100 parts by weight of the ferromagnetic powder.
Claim 5
Dependent Claim
41 words
A magnetic recording medium as claimed in claim 3, wherein the anhydrosorbitol fatty acid non-hydroxy ester compound is present in an amount in the range of 0.5 to 5 parts by weight per 100 parts by weight of the ferromagnetic powder.
Claim 6
Dependent Claim
20 words
A magnetic recording medium as claimed in claim 2, wherein the magnetic layer is further comprised of a polyisocyanate compound.
Claim 7
Dependent Claim
37 words
A magnetic recording medium as claimed in claim 5, wherein the magnetic layer is further comprised of a carbon black having a specific surface area of more than about 30 m 2 /g and a viscosity-increasing function.
Claim 8
Dependent Claim
49 words
A magnetic recording medium as claimed in claim 1, wherein said anhydrosorbitol fatty acid non-hydroxy ester compound is selected from the group consisting of anhydrosorbitol di- and tetraacetate, anhydrosorbitol di- and tetrastearate, anhydrosorbitol di- and tetraoleate, anhydrosorbitol di- and tetrapalmitate, anhydrosorbitol di- and tetralaurate, and anhydrosorbitol di- and tetramyristate.
Claim 9
Dependent Claim
33 words
A magnetic recording medium as claimed in claim 7, wherein said anhydrosorbitol fatty acid non-hydroxy ester compound is selected from the group consisting of anhydrosorbitol di- and tetraacetate and anhydrosorbitol di- and tetrastearate.
Claim 10
Dependent Claim
26 words
A magnetic recording medium as claimed in claim 6, wherein the carbon black has an average particle diameter in the range of 10 to 300 mμ.
Claim 11
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 2, wherein the support base has a thickness in the range of 2.5 to 100μ.
Claim 12
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 10, wherein the support base has a thickness in the range of 3 to 40μ.
Claim 13
Dependent Claim
43 words
A magnetic recording medium as claimed in claim 1, wherein R 1 , R 2 , R 3 and R 4 each represents a saturated alkyl group having 1 to 18 carbon atoms or an alkylene group having 2 to 18 carbon atoms.
Claim 14
Dependent Claim
33 words
A magnetic recording medium as claimed in claim 1, wherein R 1 , R 2 , R 3 and R 4 each represents a saturated alkyl group having 1 to 18 carbon atoms.
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) | 1988-02-05 | 1988-08-06 | 1989-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-05 | 1992-08-06 | 1993-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-05 | 1996-08-06 | 1997-02-05 | $7700.00 | Window Closed / Lapsed |