US4745001A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of magnetic recording medium
Assignee: Fujifilm Holdings Corp
•
Filing: 1987-01-27
•
Granted: 1988-05-17
•
Expires: 2007-01-27
Abstract
Abstract Improvement in a process for the preparation of a magnetic recording medium which comprises the steps of applying a magnetic paint onto a surface of a nonmagnetic support to form a coated paint layer, said magnetic paint comprising magnetic recording layer-forming components including a ferromagnetic powder, an abrasive and a resin component dispersed in an organic solvent, and then subjecting the coated layer to magnetic orientation, in which a step of drawing the ferromagnetic powder in the coated magnetic paint toward the surface of the support by means of a magnet is arranged in advance of the orientation step.
Inventors
- 👤 Takahito Miyoshi
- 👤 Masaaki Fujiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:55
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/842; G11B5/845; G11B5/62; G11B5/68; G11B5/70; G11B5/708
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
140 words
In a process for the preparation of a magnetic recording tape which comprises the steps of applying a magnetic paint onto a surface of a running nonmagnetic support to form a coated paint layer, said magnetic paint comprising magnetic recording layer-forming components including a ferromagnetic powder, an abrasive and a resin component dispersed in an organic solvent, and then subjecting the coated layer on a running non-magnetic support to magnetic orientation for orienting the magnetic powder in the coated paint layer along the running direction, the improvement wherein a step of drawing said ferromagnetic powder in the coated magnetic paint layer toward the surface of the support by means of a magnet having a magnetic flux density of not less than 1,500 gauss is performed prior to subjecting the coated paint layer to the magnetic orientation along the running direction.
Claim 2
Dependent Claim
140 words
In a process for the preparation of a magnetic recording tape which comprises the steps of applying a magnetic paint onto a surface of a running nonmagnetic support to form a coated paint layer, said magnetic paint comprising magnetic recording layer-forming components including a ferromagnetic powder, an abrasive and a resin component dispersed in an organic solvent, and then subjecting the coated layer on a running non-magnetic support to magnetic orientation for orienting the magnetic powder in the coated paint layer along the running direction, the improvement wherein a step of drawing said ferromagnetic powder in the coated magnetic paint layer toward the surface of the support by means of a magnet having a magnetic flux density of not less than 1,500 gauss is performed prior to subjecting the coated paint layer to the magnetic orientation along the running direction.
Claim 3
Dependent Claim
70 words
The process as claimed in claim 1, wherein said ferromagnetic powder contained in the coated paint layer is drawn by means of a magnet which is placed in the vicinity of the nonmagnetic support on the back side free from the coated paint layer in the course of running the paint-coated support, keeping the back surface of the support essentially in contact with north or south pole of said magnet.
Claim 4
Dependent Claim
30 words
The process as claimed in claim 1 or 2, wherein said ferromagnetic powder is drawn in a magnetic field having a magnetic flux density of not less than 2,000 gauss.
Claim 5
Dependent Claim
37 words
The process as claimed in claim 1, wherein said abrasive is contained in the magnetic paint in an amount of not more than 15 parts by weight based on 100 parts by weight of the ferromagnetic powder.
Claim 6
Dependent Claim
51 words
The process as claimed in claim 1, wherein said abrasive is an inorganic powder made of at least one material selected from the group consisting of SiO 2 , TiO, TiO 2 , α-Al 2 O 3 , SnO 2 , Cr 2 O 3 and α-Fe 2 O 3 .
References Cited (Backward Citations)
US3630910A
Cited
US4652461A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-17 | 1991-11-16 | 1992-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-17 | 1995-11-16 | 1996-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-17 | 1999-11-16 | 2000-05-17 | $7700.00 | Window Closed / Lapsed |