JPS598130A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To prevent the bleeding of a lubricant by incorporating fatty acid ester consisting of 18C satd. fatty acid and 3-6C aliphatic alcohol, liq. paraffin, and 12-18C fatty acid into the magnetic layer. CONSTITUTION:n-Butyl stearate, n-hexyl stearate or the like is used as fatty acid ester consisting of 18C satd. fatty acid and 3-6C aliphatic alcohol, having superior lubricity, and effective in improving wear resistance, and the desired amount is 0.5-2.0wt%. Stearic acid, myristic acid, oleic acid or the like is used as 12-18C fatty acid having a superior lubricating effect, and the preferred amount is 1/3-1 equiv. weight of the fatty acid ester. By combining liq. paraffin with said lubricants, the bleeding of the lubricants is inhibited, and the lubricating action is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording medium, and its object is to provide a magnetic recording medium that does not seep out of lubricant even when used for a long time, runs stably, and has excellent durability. It is about providing.

Magnetic recording media for computers, video, and audio come into intense sliding contact with magnetic heads during recording and playback, which can damage or abrade the magnetic layer, causing dropouts. . Therefore, it is desired that the material has excellent wear resistance. In particular, in floppy rollers, the magnetic recording medium is housed in a vinyl chloride jacket lined with non-woven fabric, so the lubricant that seeps out is absorbed by the non-woven fabric, reducing the lubricating effect at the head sliding contact area. This causes problems such as unstable running performance and further damage to the magnetic layer by the head.

Conventionally, higher fatty acids, higher aliphatic alcohols, higher fatty acid esters, and the like have been mixed into magnetic recording media as lubricants, but when a floppy disk is stored or used for a long time, the lubricants ooze out.

As a result of various studies to improve these drawbacks, the present invention has developed a combination of saturated fatty acids having 18 carbon atoms and 3 to 6 carbon atoms.
When the magnetic layer contains a fatty acid ester consisting of an aliphatic alcohol, liquid paraffin, and a fatty acid having 12 to 18 carbon atoms, the lubricant does not ooze out even when stored or used for a long time, and the running performance is improved. This was made based on the discovery that it increases stability and improves wear resistance.

The fatty acid ester used in the present invention has excellent lubricity,
Preferred fatty acid esters are saturated fatty acids having 18 carbon atoms and aliphatic anocols having 3 to 6 carbon atoms, which are effective in improving wear resistance.As such fatty acid esters, n- Examples include butynodostearate and n-hexyl stearate, which may be used alone or in combination. The amount used is 0.6-2.0% by weight
However, if it is less than that, a sufficient lubricating effect cannot be obtained, and if it is more than that, there is a risk that it may seep onto the surface of the magnetic layer.

In addition, fatty acids have 12 or more carbon atoms and have excellent lubricating effects.
18 is preferable, and examples of such fatty acids include stearic acid, myristic acid, oleic acid, etc.
These can be used alone or in a mixture of several kinds.The amount used is preferably V3 to 1 equivalent weight of fatty acid ester.If it is less than that, sufficient lubricating effect will not be obtained, and if it is more than that, it will seep onto the surface of the magnetic layer. There is a risk.

Furthermore, by using this together with the fluid rough-in, it not only suppresses the seepage of the lubricant, but also further improves the lubricating effect. Although this fluid/rough-in is effective even when used in small amounts, It is preferable to use A to 2 equivalent weights based on the total amount of the fatty acid ester and the fatty acid. The magnetic layer contains a saturated fatty acid having 18 carbon atoms and 3 to 3 carbon atoms.
In order to contain a fatty acid ester consisting of an aliphatic alcohol of 6, a liquid para-7, yne, and a fatty acid having 12 to 18 carbon atoms, these can be kneaded together with magnetic powder and a binder to form a magnetic layer. Alternatively, these may be mixed in the presence or absence of a suitable solvent and applied or sprayed onto a pre-formed magnetic layer, or by immersing the magnetic layer in a mixture of these. can also be done.

Next, a specific example of the present invention will be described.0 (Example) These kneaded materials were kneaded in a ball mill to make a magnetic paint, and a dry thickness of 2
．． It is coated and dried to a thickness of 6 μm, then calendered and cured, and then punched out into a disk shape. Both sides of the punched disks were further polished and placed in a handmade jacket lined with non-woven fabric to create a magnetic disk.

(Comparative Example 1) A magnetic disk was made in the same manner as in the example except that liquid paraffin was omitted from the paint composition of the example. (Comparative example 2) In the paint composition of the example, n-butyl stearate 3
A magnetic disk was produced in the same manner as in Example except that the weight part was changed to 1 part by weight of Otsu, 2.6 parts by weight of palmitic acid was changed to 5.9 parts by weight, and liquid paraffin was omitted.

The surface frictional resistance μk of the magnetic disks obtained in Examples and Comparative Examples 1 and 2 was measured, and their durability was tested using a floppy disk driver. The surface frictional resistance measuring device was a DFPM model manufactured by Kyowa Kagaku Co., Ltd., and measured the frictional resistance between the surface and the steel ball. In addition, the durability test was conducted using JK-875 manufactured by Matsushita Tsushin Kogyo Co., Ltd.
z signal was recorded and then heated at 40°C, 80% R. H.
After running for 200 hours under the following conditions, the quality of the test was judged by observing a decrease in output, drop-out, staining of the magnetic head, and seepage of lubricant. The table below shows the results.O As is clear from this table, the product obtained in Comparative Example 1 has no lubricating effect and has poor durability, while the product obtained in Comparative Example 2 has a lubricating effect but is lubricating. There was some oozing of the agent, and the results were not very good. On the other hand, in the case of the present invention, the lubricating effect is sufficient, the lubricant does not seep out, and the output does not decrease at all.

As described above, according to the present invention, it is possible to obtain a magnetic recording medium that does not seep out of lubricant even when used for a long time, runs stably, and has excellent durability.

Claims (1)

[Claims] Magnetic recording medium 0 containing a fatty acid ester consisting of a saturated fatty acid having 18 carbon atoms and an aliphatic alcohol having 3 to 6 carbon atoms, liquid paraffin, and a fatty acid having 12 to 18 carbon atoms