US4363850A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Maxell Ltd
•
Filing: 1980-10-24
•
Granted: 1982-12-14
•
Expires: 2000-10-24
Abstract
Abstract A magnetic recording medium which comprises a base material and a magnetic layer provided thereon. The magnetic layer comprises magnetic particles, a cellulose resin and a polyurethane resin as the binders and α-Fe 2 O 3 particles, whereby the dispersibility of the magnetic particles in the magnetic layer is enhanced without deterioration of the durability of the magnetic layer.
Inventors
- 👤 Masaaki Yasui
- 👤 Takeshi Matsuura
- 👤 Seiji Watatani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:48
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/708; G11B5/702; G11B5/7021; G11B5/7022; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/31504; Y10T428/31551; Y10T428/31609
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
85 words
A magnetic recording medium comprising a base material and a magnetic layer provided on the surface of said base material, said magnetic layer consisting essentially of magnetic particles and α-Fe 2 O 3 granular particles dispersed in a binder consisting essentially of a cellulose resin and a polyurethane resin, said α-Fe 2 O 3 particles being present in an amount of 0.5 to 10 percent by weight based on the weight of the magnetic particles, and having an average particle size of 0.5 to 2.0μ.
Claim 2
Dependent Claim
85 words
A magnetic recording medium comprising a base material and a magnetic layer provided on the surface of said base material, said magnetic layer consisting essentially of magnetic particles and α-Fe 2 O 3 granular particles dispersed in a binder consisting essentially of a cellulose resin and a polyurethane resin, said α-Fe 2 O 3 particles being present in an amount of 0.5 to 10 percent by weight based on the weight of the magnetic particles, and having an average particle size of 0.5 to 2.0μ.
Claim 3
Dependent Claim
48 words
The magnetic recording medium according to claim 1 wherein the magnetic layer further contains a trifunctional isocyanate compound having a low molecular weight in an amount of 5 to 25 parts by weight to 100 parts by weight of the combined amount of the cellulose and polyurethane resin.
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) | 1985-12-13 | 1986-06-14 | 1986-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-13 | 1990-06-14 | 1990-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-13 | 1994-06-14 | 1994-12-14 | $7700.00 | Window Closed / Lapsed |