JPS62236141A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To make mass production of magnetic recording media having a good shape and dimensional stability by forming respective films dividedly by vapor deposition in the thickness direction and executing the vapor deposition under the conditions of different substrate temps. at the time of forming a magnetic recording layer on one face of a high-polymer film and a thin film layer on the other face by a vacuum deposition method. CONSTITUTION:An SiO layer 25 is deposited by evaporation to 0.07mum on, for example, a PE terephthalate film 23 having 10mum thickness by maintaining the temp. of a cylindrical can 13 at -20 deg.C, then Co-Ni is formed to 0.05mum as the 1st magnetic recording layer 24 in oxygen kept under 1X10<-4>(Torr) by maintaining the 2nd cylindrical can 14 at -20 deg.C. The taking up direction in this treatment is an R direction. The direction is then changed over to the R direction and the taking up is executed. The can temps. are respectively maintained at 60 deg.C and the SiO layer 0.07mum 27 and the 2nd magnetic recording layer 0.05mum 26 are formed. The magnetic recording media which are free from the shape and dimensional changes are thus obtd. in a large quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a magnetic recording medium suitable for high-density magnetic recording.

Conventional technology In the field of magnetic recording, higher recording densities and shorter wavelengths of recording signals are progressing. Vapor deposition tapes produced by directly forming ferromagnetic metal thin films on polyester films using ferromagnetic metal materials such as Mi alloys using thin film forming methods such as electron beam evaporation are seen as promising, and improvements are being made in various fields. It is being [For example, foreign journal i.
IICHICTran
actions on Magnetics) vol.
MAG-21, No-3, P, P, 1217~=12
20 (1985)) Measure-3 Figure 3 is an example of a vapor deposition machine used in the production of conventional vapor deposition tape. In Figure 2, 1 is an electron gun, 2 is an evaporation source,
3 is a deposition prevention plate, 4 is a vapor deposition drum, 6 is a guide roll, 6 is a glow discharge electrode, 7 is a shutter, 8 is a sending shaft, 9
is the winding shaft.

The process of forming a Co-Ni-0 obliquely vapor-deposited film on a polyethylene terephthalate film using the apparatus shown in FIG.
The surface of the deposition drum 4 is cooled to reduce the thermal effect on the polyethylene terephthalate film used.

In particular, as the polyethylene terephthalate film used becomes thinner, its mechanical strength weakens, so cooling of the deposition drum has become important.

Problems to be Solved by the Invention However, with the above-mentioned configuration, when applied to recording equipment for outdoor use where the magnetic tape is stored in a wide range of environmental conditions, changes in shape and dimensions may affect the characteristics. This poses a big problem in practice. The present invention has been made in view of the above-mentioned circumstances, and provides a method for manufacturing a magnetic recording medium that can produce a large amount of magnetic recording media in which the occurrence of changes in shape and two dimensions during storage can be almost ignored. It is.

Means for Solving the Problems In order to solve the above problems, the method for manufacturing a magnetic recording medium of the present invention includes forming a magnetic recording layer on one side of a polymer film and a thin film layer on the other side by vacuum evaporation. Each layer is divided into layers in the thickness direction and deposited under different substrate temperature conditions.

Effect The method for producing a magnetic recording medium of the present invention has the above-described structure, and by vapor depositing on both sides of a polymer film at multiple temperature stages, the stress balance can be maintained over a wide range, so it can be used in a wide range of environments. Magnetic recording media with very good shape and dimension stability can be manufactured in large quantities.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a vapor deposition apparatus used to carry out the manufacturing method of the present invention. FIG. 2 is an enlarged sectional view of a magnetic recording medium obtained according to the present invention. In FIG. 1, 10 is a web, 11 is a first shaft, 12 is a second shaft, 13 is a first cylindrical can, 14 is a second cylindrical can, 16 is a first evaporation source, 16 is a second evaporation source, and 17 is a The first vapor stream, 18 is the second vapor stream, 1
9 is a first mask, 2o is a second mask, 21 is a shielding plate,
Reference numeral 22 denotes a guide roll, which can be wound in both the F direction and the R direction shown by arrows in the figure.

In FIG. 2, 23 is a polymer film, 24 is a first magnetic recording layer, 26 is a first thin film layer, 26 is a second magnetic recording layer, 2
7 is a second thin film layer.

The present invention will be outlined in FIGS. 1 and 2.

Using the apparatus shown in FIG. 1, a 5i0 layer 25 (first thin film layer) of 0.07 μm was deposited on the polyethylene terephthalate film 23 with a thickness of 10 μm by first setting the temperature of the first cylindrical can 13 to −20″C, and then 2nd cylindrical can 1 by oblique deposition
4 to the same <-20"C, Go-Ni (Ni 20"
wt%) was formed as a 0.06 μm first magnetic recording layer 24 in oxygen at 1×10 (Torr). [
In this process, the winding direction is the F direction. ] Next, switch to the R direction, wind up, set the can temperature to 60°C, and form an 8i0 layer of 0.07p Ia2.
7 (second thin film layer) and a second magnetic recording layer 26 having a thickness of 0.05 μm were formed in the same manner.

This was inserted into a cassette as an 8InI 1-width magnetic tape, stored at -10°C, 20'C, and 60''Cl8o'C for one month, and then stored at 23°C to check for changes in dimensions from the initial stage. Evaluation was made by measuring skew.

For comparison, a polyethylene terephthalate film with a thickness of 10 μm was used, and Go-Ni (ui 2ow
t%) in oxygen at 1x 10 (Torr)
．． A magnetic recording layer was formed by oblique vapor deposition of 1 μm under the same incident angle conditions, and a flattened tape (comparative example) was used.

As a result of research using 8mm video specifications, the product of the present invention showed -1 in 40 arbitrarily selected cassettes (1 environment, 10 cassettes).
4 to 6 at 0°Cl2o''C, 60'C, and 80''C (
μ5ec), s ~6.7 (μ5ec), e
, e ~ B, 0 (μ5ec), 4. e ~s, s
(Hec)t, while the tapes of comparative examples were 19 to 3B (μ5ec).

11~1e (μ5ec), 5~22 (μ5ec
), 7-31 (μ5ec), the variation was large, the skew was also large, and there were many parts that caused practical problems.

In the example, the vapor deposition was performed in two parts, but if necessary, the vapor deposition may be performed three to four times, or the vapor deposition could be continued at different temperatures using an apparatus configured without winding in both directions. You can also do it by Note that satisfactory results can be obtained by performing vapor deposition near the upper and lower limits of the temperature range in which reliability must be ensured.

The order of vapor deposition, that is, whether or not to deposit the magnetic recording layer first, and whether or not to start from the low temperature side can be selected as appropriate.

Note that the manufacturing method of the present invention can be used for both magnetic tapes and magnetic disks.

Effects of the Invention As described above, the method for manufacturing a magnetic recording medium of the present invention has the advantage that it is possible to obtain a large quantity of magnetic recording media with almost no change in shape or dimension even if the storage temperature range is widened. You can get the same effect.

[Brief explanation of drawings]

Figure 1 is a block diagram of the main parts of a vapor deposition apparatus used to carry out the manufacturing method of the present invention, Figure 2 is an enlarged sectional view of a magnetic recording medium that can be manufactured by the present invention, and Figure 3 is a conventional magnetic recording medium. FIG. 2 is a configuration diagram of main parts of a vapor deposition apparatus used for manufacturing. 10... Web, 13... First cylindrical can, 14... Second cylindrical can, 16...
...First evaporation source, 16... Second evaporation source, 23... Polymer film, 24...
First magnetic recording layer, 26...First thin film layer, 2
6... Second magnetic recording layer, 27... First thin film layer.

Claims (1)

[Claims] When forming a magnetic recording layer on one side of a polymer film and a thin film layer on the other side using a vacuum evaporation method, each layer is vapor-deposited separately in the thickness direction, and the layers are vapor-deposited under different substrate temperature conditions. A method for manufacturing a magnetic recording medium.