JPS63263631A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a good lubricating characteristic and durability over a wide temp. range by incorporating oleic acid and isotridecyl oleate into a magnetic layer at the time of forming high-density magnetic recording media such as floppy disks, video tapes and digital audio tapes. CONSTITUTION:The oleic acid to be incorporated into the magnetic layer is unsatd. fatty acid of 18C and the isotridecyl oleate is the ester of oleic acid of 18C and isotridecyl alcohol which is primary alcohol of 13C. These lubricants are mixed with a magnetic coating compd. consisting of magnetic powder, binder resin, org. solvent, etc., in order to incorporate said lubricants into the magnetic layer. These lubricants or otherwise dissolved in an org. solvent such as methyl ethyl ketone and the soln. is coated or sprayed on the previously formed magnetic layer. The magnetic recording medium having a high density and high capacity is thus adequately formed.

Description

[Detailed description of the invention] Industrial applications The present invention applies to floppy disks and video tapes.

It relates to high-density magnetic recording media such as digital audio tapes. - Conventional technology In recent years, magnetic recording media made by coating a base film such as polyester with magnetic paint made of magnetic powder, binder resin, organic solvent, etc. have become higher in density and capacity. During use, wear of the magnetic layer caused by contact with magnetic heads, pads, etc. at high speeds has become a problem. Many methods of increasing the durability of magnetic recording media include lowering contact resistance and reducing wear by mixing or overcoating a substance that promotes surface lubrication (hereinafter referred to as a lubricant) into the magnetic layer. It is used. Liquid paraffin is one such lubricant.

Higher fatty acids and esters of higher fatty acids are often used. For example, JP-A No. 60-138726, JP-A No. 60-138728, and JP-A No. 60-256919.
Publications, etc.

Problems to be Solved by the Invention However, despite the above efforts, the durability of magnetic recording media has not yet been sufficiently improved.

In view of the above-mentioned problems, it is an object of the present invention to provide a magnetic recording medium whose magnetic layer has good lubrication properties over a wide temperature range and is excellent in durability.

Means for Solving the Problems In order to solve the above problems, the present invention produces a magnetic recording medium configured to contain oleic acid and isotridecylolate in the magnetic layer.

Effect of the present invention With the above-described configuration, it is possible to maintain extremely low friction when the surface of the magnetic layer comes into contact with a magnetic head, pad, etc. over a wide temperature range, and as a result, the wear resistance of the magnetic layer is significantly improved. See improvement.

Example An embodiment of the present invention will be described below.

The oleic acid used in the present invention has 18 carbon atoms.
It is an unsaturated fatty acid with good lubricating properties over a wide temperature range. Isotridecyl oleate is an ester of oleic acid, which has 18 carbon atoms, and isotridecyl alcohol, which is a primary alcohol with 13 carbon atoms. It is appropriate that the blending amount of isotridecyl oleate is within the range of 2 to 9% by weight based on the magnetic powder.If it is less than this, the lubricating effect will be lacking, and if it is too much, the magnetic powder will not be effective. It bleeds out onto the surface of the layer, contaminating the magnetic head and causing a reduction in output.

In order to incorporate olein M and intridecyl oleate as lubricants in the magnetic layer, the magnetic layer is formed by mixing them with a magnetic paint consisting of magnetic powder, binder resin, Ja-containing solvent, etc. These can be obtained by dissolving these in a suitable organic agent such as methyl ethyl ketone to prepare a solution and coating or spraying it onto a previously formed magnetic layer, or by dipping the magnetic layer in the solution.

Example 1 A magnetic paint was prepared by mixing and dispersing the compositions shown in Tables 1 and 2 using a ball mill.
A dry thickness of 2 on both sides of a 5 micron polyester film.
Apply to a thickness of about microns. After drying this,
A magnetic floppy disk was produced by cutting out a donut shape. Among the examples shown in Table 2, 5 from B to F
An example is one in which the amounts of oleic acid and isodecyl oleate are within the appropriate amount ranges indicated above.

(Margins below) (Margins below) Comparative Example In the composition shown in Example No. 2 shown in Table 2, isodecyl oleate was placed in ethyl oleate, tA, t, and all others were magnetically applied using magnetic paint prepared in the same manner. I made a floppy disk.

The magnetic floppy disks obtained in the above Examples and Comparative Examples were inserted into a dirt-preventing cover jacket and loaded into a recording/reproducing device, and the pad pressure was set at 25g10! under conditions of 0°C to 50°C. It was rotated at 300 rpm+s while being brought into contact with a magnetic head, and the running time until the output decreased to 80% was measured. Table 3 shows the results, and it is clear that among the Examples, Examples B to F in which appropriate amounts of oleic acid and isotridecylolate were mixed had excellent durability.

Effects of the Invention As shown above, the magnetic recording medium obtained by the present invention has excellent durability over a wide temperature range, and the present invention can produce a high-density, high-capacity magnetic recording medium. This is an extremely important invention.

Claims (1)

[Claims] A magnetic recording medium having a magnetic layer containing oleic acid and isotridecylolate.