Stock material or miscellaneous articles – Composite – Of inorganic material
Patent
1990-09-05
1994-02-08
Thibodeau, Paul J.
Stock material or miscellaneous articles
Composite
Of inorganic material
428336, 428694BN, 428694BM, 428900, B32B 516, G11B 566
Patent
active
052847160
DESCRIPTION:
BRIEF SUMMARY
FIELD OF TECHNOLOGY
The present invention relates to improvements in a magnetic recording medium such as a magnetic tape, a magnetic sheet, a magnetic disk, and the like.
BACKGROUND OF TECHNOLOGY
Conventionally, a magnetic recording medium is manufactured by coating magnetic material to a support and then dried, wherein ferromagnetic particles, a hardening agent, a dispersion agent, an abrasive, a lubricant, a matting agent, an antistatic additive, and other additives are added into a binder of the magnetic coating material and an adequate solvent is also added if necessary.
In order to improve the chemical stability of magnetic material, the following conventional method is widely known: a small amount of nickel, cobalt, titanium, silicon, and aluminum is added into the magnetic material in the form of a metal, a salt or an oxide; or the surface of the magnetic material is treated by the elements described above.
Conventionally, identical magnetic materials have been used for both the upper and lower layers of a multilayer magnetic recording medium in which magnetic materials treated by silicon, aluminum, and the like are used. For that reason, the content of silicon, aluminum and the like of magnetic materials in the upper and lower layers are equal.
However, this type of magnetic recording medium has the following disadvantages: after drying in the manufacturing process, the conveyance rollers (the conveyance rollers will be called the rollers hereafter in this specification) to convey the magnetic recording medium are stained by the magnetic recording medium; and the running efficiency of the magnetic recording medium is lowered when the temperature and humidity are high.
The objects of the present invention are to provide a magnetic recording medium characterized in that: the magnetic recording medium does not stain the conveyance rollers to convey the magnetic recording medium after the drying process during manufacture; and the running efficiency of the magnetic recording medium is high even when the temperature and humidity are high.
Another object of the present invention is to provide a magnetic recording medium characterized in that: the electromagnetic conversion characteristics are excellent; both sliding noise and dropout (D/O) are low; and the magnetic recording medium is suited for video tape use.
DISCLOSURE OF THE INVENTION
The magnetic recording medium of the present invention comprises the first magnetic layer (the lower layer) and the second layer (the upper layer) provided on a nonmagnetic support. The magnetic recording medium of the present invention is composed in such a manner that A<B, wherein A wt parts of at least one of Si and Al are contained in 100 wt parts of the magnetic materials of the first magnetic layer and B weight parts of at least one of Si and Al are contained in 100 wt parts of the magnetic materials of the second magnetic layer. A or B is the sum of the weight parts of Si and Al in each magnetic material.
The magnetic materials used in each magnetic layer can contain either Si or Al, or can contain a mixture of Si and Al. The magnetic layer can contain both Si and Al. It is preferable that A and B are defined as 0<A<0.1 and 0.05<B<2.0. It is more preferable that B is not less than 0.1 and not more than 1.0.
In the case of A>0.1, the running efficiency of the magnetic recording medium tape is a little lowered and the tape edges tend to be damaged when the temperature and humidity are high.
When B is not more than 0.1, the conveyance rollers in the drying process and the heat rollers in the calender process tend to become stained.
On the other hand, when B is not less than 2, the conveyance rollers and heat rollers tend to become stained. In order to improve the dispersion of the ferromagnetic powder in the magnetic layer and to obtain excellent electromagnetic conversion characteristics and running efficiency, it is preferable that Si of 0.3 to 1.0 wt% or Al of 0.05 to 0.3 wt is contained in the magnetic materials of the second magnetic la
REFERENCES:
patent: 4323621 (1982-04-01), Kober et al.
patent: 4911951 (1990-03-01), Ogawa et al.
patent: 4980230 (1990-12-01), Saito et al.
patent: 5035856 (1991-07-01), Koyama et al.
Kawabe Shigetoshi
Koyama Noboru
Nakajima Takeshi
Nakano Yasushi
Namiki Takemasa
Bierman Jordan B.
Kiliman Leszek
Konica Corporation
Thibodeau Paul J.
LandOfFree
Magnetic recording medium does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetic recording medium, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic recording medium will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-696815