JPS598132A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To prevent the bleeding of a lubricant by incorporating a mixture of 12-18C fatty acid with liq. paraffin and montan wax into the magnetic layer. CONSTITUTION:Stearic acid, myristic acid, oleic acid or the like is used as 12- 18C fatty acid having superior lubricity, and the desired amount is 0.5-2wt%. Liq. paraffin has 5-15C, and the amount is 0-1 equiv. weight of the fatty acid. By combining montan wax represented by the structural formulae with said lubricants, the bleeding of the lubricants is inhibited, and the lubricity can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording medium, and its purpose is to provide a magnetic recording medium that does not seep out of lubricant even after being stored or used for a long period of time, has stable running performance, and has excellent durability. The object of the present invention is to provide a magnetic recording medium that has a unique structure.

Magnetic recording media for computers, video cameras, audio systems, etc. come into strong sliding contact with magnetic heads during recording and reproduction, which can damage or abrade the magnetic layer, causing dropouts. Therefore, a magnetic recording medium with low surface friction resistance and excellent wear resistance is desired.

In particular, in Freonbitisf, 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, lubricants such as high-quality 1-mika acid and fluid rough-in have been mixed into magnetic recording media, but when this magnetic recording medium is applied to a polyester substrate and dried and hardened, it becomes lubricant. The agent seeps out onto the surface and evaporates, reducing the lubricating effect.

Even if the lubricant does not evaporate during drying and curing, if it is stored or used for a long time, the lubricant will seep out to the surface and be absorbed by the non-woven fabric lining the jacket, reducing its lubricating effect.

Conventional lubricants use higher fatty acids with 12 to 18 carbon atoms and liquid paraffin (6 to 15 carbon atoms), but these have relatively low molecular weight because their molecular weights are not large enough. If it is blended in an amount sufficient to easily migrate and obtain a sufficient lubricating effect, it will seep onto the surface of the magnetic layer.

The present invention has been made to improve these drawbacks. As mentioned above, if the molecular weight is not large enough, the lubricant will seep out from the surface, so it is necessary to use a hydrocarbon with a molecular weight of about 1000 or more. But 21. For C rough fish hydrocarbons, +
1';llu'+ is all solid, and it is difficult to knead it with pine goo. However, by using monotan wax together with higher fatty acids, liquid paraffin, etc., the seepage of the lubricant described in 1fj can be suppressed,
Durability can be improved.

The fatty acid used in the present invention preferably has 12 to 18 carbon atoms and has excellent lubricity. Examples of such fatty acids include stearic acid, myristic acid, and oleic acid. Used alone or in combination. The amount used is preferably 0.5 to 2.0% by weight; 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 will seep onto the surface of the magnetic layer.

In addition, liquid paraffin has approximately 5 to 15 carbon atoms.
If the amount is less than this, it will be a gas, and if it is more than this, it will be a solid. The amount used is preferably O to 1 equivalent weight to the fatty acid, and if it is more than that, there is a risk that it will seep onto the surface of the magnetic layer.

In addition, Toreni Montan wax ', c (Jl
By using the lubricant, seepage of the lubricant can be suppressed and lubricity can be improved. As this type of wax, HOECH8T Co., Ltd. Hegistwanox V
, H8-1, E, S, OP, KFO, etc.) Hekis\Tosoxox is effective even when used in small amounts, but it is preferable to use 0.5 to 2.0% by weight.

This Hexstowanox mainly has the following shapes.
In m, the fatty acids interact with each other and behave as if they had twice the molecular weight. For this reason +
Both type, n, and IU have sufficiently large molecular weights to suppress migration into the magnetic layer.

In order to contain a higher fatty acid having 12 to 18 carbon atoms or a mixture of this and liquid paraffin together with Hoechstoxox, these can be kneaded together with magnetic powder and pineapple to form a magnetic layer, or these can be mixed in an appropriate manner. This may be carried out by mixing in the presence of a suitable solvent and coating or spraying the mixture onto a pre-formed magnetic layer, or by immersing the magnetic layer in a mixed solution of these.

Next, specific examples of the present invention will be described.

(Example) Composition with stearic acid, liquid paraffin.

Try blending Hextowanox E (t18n) in the proportions shown in Table 1 (Nos. 1-2), knead these mixtures in a ball mill to make a magnetic coating, and dry it on both sides of a 75 μm thick polyester film. It was coated and dried to a thickness of 2.5 μm, then calendered and cured, and then punched out into a disk shape.

Both sides of the punched disk were further polished to make it smoother and placed in a PVC jacket lined with non-woven fabric to create a magnetic tissue.

(Noss Dingyihaku) Table 1 (Memorial positions are parts by weight) (Comparative example) In the paint composition of the example, only Hoechstsonox E was omitted from 1 trial shrine 1 (3, and the amount of lubricant was Sample 4 is a sample in which only Hoechstosox E is blended as a lubricant, and Sample 4 is a sample in which Hoechstosox E is not blended without changing the ratio of stearic acid and liquid paraffin in Test 11 and the total amount of lubricant. A magnetic disk was manufactured using sample 5 in the same manner as in the example.

The surface frictional resistance μk of the magnetic disks obtained in Examples and Comparative Examples was measured, and their durability was tested using a floppy disk driver. Surface Frictional Resistance Measurement The frictional resistance between the surface and the steel ball was measured using a DFPM model manufactured by Kyowa Risugaku Co., Ltd. For the durability test, JK-875 manufactured by Matsushita Tsushin Kogyo Co., Ltd. was used, a reliability of 125kH2 was recorded, and after running for 200 hours under the conditions of 400C18o%R,H, the output Quality was judged by observing deterioration, dropout, dirt on the magnetic head, and seepage of lubricant. Table 2 shows the results.

Table 2 As is clear from Table 2, it was found that sample 3 had low Iri, lubricating effect, and extremely poor wear resistance. Samples 4 and 5 had a lubricating effect, but the amount of medium-lubricant particles was high, and seepage onto the surface of the magnetic layer was observed. On the other hand, the device according to the present invention exhibits a sufficient lubricating effect, does not seep out of lubricant, and does not have any reduction in output.

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, has stable running, and has excellent durability.

Claims (1)

[Claims] A magnetic recording medium containing a fatty acid having 12 to 18 carbon atoms or a mixture thereof with liquid paraffin, and a montan wax wax.