KR900002613B1 - The method of producing magnetic recording carrier - Google Patents

Abstract

A method for producing a magnetic recording carrier comprises (a) dispersing magnetic substance and lubricant [N-substd. fatic acid amide deriv. of formula (I) having polyoxyethylene gp., 0.5-10 wt.% to adhesive into high mol. wt. resin adhesive to prep. a magnetic paint and (b) painting it onto the base film. In (I), R is C5-21 fatty acid hydrocarbon; x and y are each 1-10.

Description

Method of manufacturing magnetic recording medium

The present invention relates to a method of manufacturing a magnetic recording medium, and more particularly, to a method of manufacturing a magnetic recording medium having excellent wear resistance and runability by using a nitrogen-substituted fatty acid amide derivative having the following structural formula as a lubricant.

Wherein R is a _C5-21 fatty acid hydrocarbon, x, y is an integer from 1 to 10.

In general, the magnetic recording medium should be excellent in running because it has to run for a long time through a magnetic head or various guide rolls. If the driving is unstable, the electronic conversion characteristics are deteriorated and the magnetic recording medium tends to be easily worn. In the case of manufacturing a recording medium, it is necessary to first put emphasis on excellent wear resistance and runability.

For this reason, as a method for improving the runability of a magnetic recording medium, esters of higher fatty acids and higher alcohols, silicone compounds, or phosphate esters have been used as lubricants. For example, US Pat. It is described that esters of alcohols are added as lubricants in the preparation of the magnetic recording medium.

However, when the fatty acid ester is added to a certain level or less, the effect on the runability of the magnetic recording medium does not appear. On the contrary, when the excessive amount is used, the interaction between the polymer resin adhesives is rather reduced. There is a possibility that the magnetic layer is softened due to poor properties, so that the control of the amount of addition was quite difficult.

On the other hand, US Patent Nos. 4,171,406 and 4,156,052 use a silicone compound as a lubricant unlike the above technique, but in this case, the silicon compound used in this case is also poorly compatible with the polymer resin adhesive, and formed by magnetic recording. The drawback is that the adhesion of the media increases.

On the other hand, US Patent No. 4,018,968 discloses a technique for using a phosphate ester compound as a lubricant, unlike the above technique, but at this time, due to the intrinsic properties of the phosphate ester, phosphate ester is a binder used in the preparation of the medium. It is not good because it hydrolyzes the polymer resin adhesive, and the trace amount of phosphoric acid contained in the phosphate ester is a disadvantage that the magnetic properties tend to deteriorate because it corrodes or damages the magnetic body.

Accordingly, the present invention is to solve the conventional defects of the present invention, a method of manufacturing a magnetic recording medium having excellent compatibility with the polymer resin adhesive, excellent wear resistance and running performance without deteriorating the magnetic layer or contaminating the magnetic head. The purpose is to provide.

Hereinafter, the present invention will be described in detail.

The present invention is to prepare a magnetic paint by dispersing a magnetic material in a polymer resin adhesive and applying it on a base film to prepare a magnetic recording medium, which is represented by the following structural formula as a lubricant in the manufacture of the magnetic paint and has a polyoxyethylene group nitrogen It is a method for producing a magnetic recording medium, characterized in that about 0.5 to 10% by weight of the substituted fatty acid amide derivative is added to the polymer resin adhesive.

Wherein R is a _C5-21 fatty acid hydrocarbon, and x and y are integers from 1 to 10.

In this compound, if the carbon number of the fatty acid hydrocarbon group is less than 5 or more than 21 and x and y are less than 1 or more than 10, the lubrication is insufficient, but the reason is not clear.

Meanwhile, in the present invention, for example, the polymer resin adhesive may be selected from polyvinyl chloride copolymer, nitrocellulose or polyurethane, and as the lubricant, a polyoxymethylene group having a nitrogen-substituted amide derivative represented by the above structural formula is used. However, the addition amount is preferably used in the range of 0.5 to 10% by weight with respect to the polymer resin adhesive as a binder as described above, if it is added below 0.5% by weight, the lubrication action is not good, on the contrary 10 weight If it is added in excess of%, it is not good because the magnetic layer softens and shows adhesiveness.

This invention is described in more detail in the following examples as follows.

Numerical evaluation method of the embodiment in the present invention is evaluated by the following criteria.

[Friction coefficient]

Measured according to ADTM D 1894-73, the smaller the coefficient of friction, the better.

[Still Duration]

Using a magnetic recording medium as a video tape, an image is first recorded on a tape and a still image is reproduced at the time of reproduction. At this time, measure the time from the stop time until the image is distorted. The longer the time, the better the driving performance and the better the durability.

[Adhesiveness]

Implemented according to JIS K6280, the better the physical properties of the magnetic recording medium, the better the adhesion.

EXAMPLE

16 g of nitrocellulose was dissolved in 250 g of a solution of methyl ethyl ketone and toluene of 1: 1, and 160 g of magnetic material was added and dispersed for 24 hours under a bowl. Then, 16 g of polyurethane and 1 g of a nitrogen-substituted fatty acid amide derivative having a polyoxyethylene group having the above structural formula were added to 50 g of a solution having a ratio of 1: 1 of methyl ethyl ketone and toluene, and then dispersed for 8 hours under a bowl, followed by polyisocyanate. Add 6 g.

The magnetic coating thus obtained was applied onto a polyethylene terephthalate base film, oriented and dried, and then the surface of the magnetic layer was treated with hot-pressed calenderol and heat treated at 60 ° C. for 24 hours. The product thus cut is cut to an appropriate width to make a magnetic recording medium.

[Comparative Example]

All procedures were carried out in the same manner as in the above embodiment, but instead of the nitrogen-substituted fatty acid amide derivatives used as lubricants, sorbitol distearate was used to make a magnetic recording medium. The results obtained through the above evaluation test for the samples obtained in Examples and Comparative Examples are shown in Table 1 below.

TABLE 1

As described above, the magnetic recording medium prepared according to the present invention, unlike the conventional magnetic recording medium, has a polyoxyethylene group as a lubricant and is compatible with the polymer resin adhesive by using a nitrogen-substituted fatty acid amide derivative represented by the above structural formula. In this case, even when a small amount is used, the magnetic layer does not deform or deteriorate, and shows excellent lubrication, and even when the magnetic recording medium is traveling, friction between the magnetic head and various guide rolls is reduced, which may contaminate or damage the magnetic head or guide roll. At the same time, wear resistance and running performance are excellent.

Claims (1)

In preparing a magnetic paint by dispersing a magnetic material in a polymer resin adhesive and applying the same on a base film, the magnetic recording medium is represented by the following structural formula as a lubricant in the manufacture of the magnetic paint, and is a nitrogen-substituted fatty acid amide derivative having a polyoxyethylene group. Method of producing a magnetic recording medium, characterized in that by adding about 0.5 to 10% by weight based on the polymer resin adhesive.

Wherein R is a _C5-21 fatty acid hydrocarbon, and x and y are integers from 1 to 10.