Patent US792126A successfully refreshed from Google Patents.
Patent US4154895A successfully refreshed from Google Patents.
US4154895A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording member
Assignee: Fujifilm Holdings Corp
•
Filing: 1977-12-20
•
Granted: 1979-05-15
•
Expires: 1997-12-20
Abstract
Abstract In a magnetic recording member comprising a non-magnetic support having provided thereon a magnetic layer comprising finely divided ferromagnetic powders dispersed in a binder, in which the binder comprises about 10 to about 70 wt% of (a) a polyester-polyurethane resin and about 30 to about 90 wt% of (b) a synthetic non-drying oil modified alkyd resin and (c) a polyisocyanate, wherein the molar ratio of the isocyanate groups present in the polyisocyanate (c) to the hydroxyl groups present in the synthetic non-drying oil-modified alkyd resin (b) ranges from about 0.8:1 to about 2.0:1. The binder system in accordance with the present invention provides excellent magnetic properties, particularly improved squareness ratio and 5 MHz output. The binder system of the present invention also enables the use of finely divided ferromagnetic alloy powders, with excellent magnetic properties being maintained when magnetic recording members are produced therefrom.
Inventors
- 👤 Hiroshi Ogawa
- 👤 Masashi Aonuma
- 👤 Matsuaki Nakamura
- 👤 Yasuo Tamai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:58
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70605; G11B5/70621; G11B5/702; G11B5/7021; G11B5/70615; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31565; Y10T428/31609
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
99 words
A magnetic recording member comprising a non-magnetic support having thereon a magnetic layer comprising finely divided ferromagnetic powders dispersed in a binder, said binder comprising about 10 to about 70 wt% of (a) a polyester-polyurethane resin and about 30 to about 90 wt% of (b) a synthetic non-drying oil-modified alkyd resin having a hydroxyl value of from about 50 to about 200 and (c) a polyisocyanate, wherein the molar ratio of the isocyanate groups present in the polyisocyanate (c) to the hydroxyl groups present in the synthetic non-drying oil-modified alkyd resin (b) ranges from about 0.8:1 to about 2.0:1.
Claim 2
Dependent Claim
99 words
A magnetic recording member comprising a non-magnetic support having thereon a magnetic layer comprising finely divided ferromagnetic powders dispersed in a binder, said binder comprising about 10 to about 70 wt% of (a) a polyester-polyurethane resin and about 30 to about 90 wt% of (b) a synthetic non-drying oil-modified alkyd resin having a hydroxyl value of from about 50 to about 200 and (c) a polyisocyanate, wherein the molar ratio of the isocyanate groups present in the polyisocyanate (c) to the hydroxyl groups present in the synthetic non-drying oil-modified alkyd resin (b) ranges from about 0.8:1 to about 2.0:1.
Claim 3
Dependent Claim
28 words
The magnetic recording member as claimed in claim 1, wherein said synthetic non-drying oil-modified alkyd resin is a branched chain alkyl monocarboxylic acid glycidyl ester modified alkyd resin.
Claim 4
Dependent Claim
45 words
The magnetic recording member as claimed in claim 1, wherein said polyisocyanate (c) is an adduct of a diisocyanate and a trihydric polyol, a pentamer of a diisocyanate, or a decarboxylation product obtained by reacting 3 mols of a diisocyanate and 1 mol of water.
Claim 5
Dependent Claim
42 words
The magnetic recording member as claimed in claim 1, wherein the molar ratio of the isocyanate groups present in said polyisocyanate (c) to the hydroxyl groups present in said synthetic non-drying oil-modified alkyd resin (b) ranges from about 1.0:1 to about 1.8:1.
Claim 6
Dependent Claim
31 words
The magnetic recording member as claimed in claim 1, wherein the proportion of said polyester-polyurethane (a) ranges from about 20 to about 40 wt% to the total amount of said binder.
Claim 7
Dependent Claim
21 words
The magnetic recording member as claimed in claim 1, wherein said finely divided ferromagnetic powders are finely divided ferromagnetic alloy powders.
Claim 8
Dependent Claim
26 words
The magnetic recording member as claimed in claim 6, wherein said finely divided ferromagnetic alloy powders are finely divided liquid phase reduction type ferromagnetic alloy powders.
Claim 9
Dependent Claim
37 words
The magnetic recording member as claimed in claim 1, wherein said synthetic non-drying oil is a paraffin oxidized aliphatic carboxylic acid, a Ziegler aliphatic carboxylic acid, an oxo aliphatic carboxylic acid or a Koch aliphatic carboxylic acid.
Claim 10
Dependent Claim
34 words
The magnetic recording member as claimed in claim 8, wherein said Koch aliphatic carboxylic acid is obtained using the Koch process by adding CO to an olefin in the presence of an acid catalyst.
References Cited (Backward Citations)
US4049871A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-14 | 1982-11-13 | 1983-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-14 | 1986-11-13 | 1987-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-14 | 1990-11-13 | 1991-05-15 | $7700.00 | Window Closed / Lapsed |