JPS6124026A - Manufacture of magnetic recording medium - Google Patents

Abstract

PURPOSE:To suppress effectively fold by adjusting the surface temperature of a guide roll to >=15 deg.C so as to improve the mating with a base. CONSTITUTION:The base 6 made of a polyester film moves on a peripheral side face of a cylindrical can 5 from a supply roll 7 via guide rolls 8, 9 and wound on a winding roll 12 via 10, 11. Then a heater is incorporated in guide rolls 8-11 and the surface temperature is adjusted to 15-80 deg.C, the base 6 is run and guided while being adhered closely in an excellent way to the guide rolls. Further, since the base reaches a comparatively high temperature at the same time, the quantity of charge is decreased and folds are suppressed effectively.

Description

[Detailed Description of the Invention] [Technical Field and Objectives] The present invention relates to a method for manufacturing a magnetic recording medium having a ferromagnetic metal thin film layer as a recording layer, and its purpose is to reduce wrinkles that occur during the formation of the ferromagnetic metal thin film layer. It is an object of the present invention to provide a method for manufacturing the above-mentioned magnetic recording medium that suppresses wrinkles and is wrinkle-free.

[Background technology]

A magnetic recording medium having a ferromagnetic metal thin film layer as a recording layer is usually produced by guiding a substrate such as a polyester film along the circumferential side of a cylindrical can via various guide rolls disposed in a vacuum chamber. It is made by vacuum-depositing a ferromagnetic material onto this substrate.

However, with this manufacturing method, the substrate may stretch due to radiant heat from the ferromagnetic material evaporation source, friction between the extremely smooth substrate and each guide roll, or secondary electrons from the electron gun used to melt the ferromagnetic material. The running of the board may be hindered by static electricity caused by such things, and wrinkles may occur on the running board (particularly if the guide roll is relatively low temperature, the adhesion of the board to the guide roll is poor, and Wrinkles are likely to occur due to the large amount of lubricant.For this reason, it is necessary to improve the mechanical precision between each guide roll, or to moderate the surface roughness of the substrate and guide roll, and to apply lubricant to the back side of the substrate. Efforts have been made to eliminate the unbalance of tension applied to the substrate, reduce friction between the substrate and each guide roll, and the resulting electrical charge, and thereby suppress the occurrence of wrinkles, but this is still insufficient. The generation of wrinkles cannot be suppressed, and in particular, these methods cannot effectively suppress wrinkles that occur when the substrate is guided by relatively low-temperature guide rolls.

[Summary of the invention]

As a result of conducting various studies on guide rolls in order to improve this drawback, the present invention found that when the guide rolls are heated and their surface temperature is adjusted to a temperature of 15°C or higher, the adhesion of the substrate to the guide rolls improves, and the electrostatic charge increases. This was done based on the discovery that the amount of wrinkles was reduced, the compatibility with the substrate was improved, and the occurrence of wrinkles was effectively suppressed.The surface temperature of the guide roll was adjusted to a temperature of 15°C or higher, A ferromagnetic metal thin film layer is formed by directing a vapor flow of ferromagnetic material from a ferromagnetic material evaporation source onto a substrate that is guided by the guide rolls and moves along the substrate support. be.

The present invention will be described below with reference to the drawings.

Figure 1 shows a cross-sectional view of the vacuum evaporation equipment.
is a vacuum chamber, and the inside of this vacuum chamber 1 is divided into sections by a partition plate 2, and maintained in a vacuum by exhaust systems 3 and 4, respectively. Reference numeral 5 denotes a cylindrical can disposed in the center of the vacuum chamber 1 spanning the two compartmented chambers. It moves along the circumferential side of this cylindrical can 5 and is wound onto a winding roll 12 via guide rolls 10 and 11. During this time, a ferromagnetic material evaporation source 13 disposed at the bottom of the vacuum chamber 1 faces the substrate 6 moving along the circumferential side of the cylindrical can 5.
4 is heated and evaporated, and this vapor flow is directed toward the substrate 6 for vapor deposition.

Here, the guide rolls 8.9.10.11 have a built-in heater, and this heater adjusts the surface temperature to 15°C or higher, and the substrate 6 is placed on these heated guide rolls. Vacuum deposition is performed while being guided. Thus these guide rolls 8.9.10.1
1, the surface temperature of each of them is adjusted to a temperature of 15° C. or higher, so that the substrate 6 is guided while being in close contact with these guide rolls. At the same time, since the temperature of the substrate is heated to a relatively high temperature by these guide rolls, the amount of charge is also reduced, and the generation of wrinkles is effectively suppressed. In this way, these guide rolls have a surface temperature of 1
It is preferable to adjust the heating to a temperature of 5° C. or higher. If the surface temperature of the guide roll is lower than 15° C., the adhesion of the substrate 6 to the guide roll is poor and the amount of charge is large.
The generation of wrinkles cannot be suppressed well.

Among these guide rolls 8.9.10.11, the guide rolls 8 and 9 completely prevent wrinkles from occurring on the substrate 6 on the surface of the cylindrical can 5 after that when the surface temperature thereof is set to 40°C or higher. Therefore, it is more preferable to adjust the temperature to 40°C or higher, and the guide roll 10
It is more preferable to adjust the surface temperature of 11 to 35° C. or higher, since wrinkles that are subsequently introduced into the winding roll 12 can be completely prevented. However, when using a substrate with a low heat-resistant temperature, such as a polyester film, if the surface temperature of any guide roll reaches 80°C or higher, outgas from the surface of the polyester film will cause the cylindrical can 5 to 8.9.10.1 These guide rolls may cause poor adhesion or heat shrinkage.
The temperature adjustment in step 1 is preferably carried out within the range of 15 to 80°C. In addition, when suppressing the occurrence of wrinkles by adjusting the surface temperature of these guide rolls, the reduction in wrinkles becomes more pronounced as the thickness of the substrate becomes thinner, and the longer the contact length with the guide rolls 10 and 11, the longer the contact time increases. The more you use it, the better the results will be.

As the substrate for forming the ferromagnetic metal thin film layer, a plastic film made of commonly used polymer moldings such as polyester, polyimide, polyamide, etc. and a nonmagnetic metal plate such as copper are used to form the ferromagnetic metal thin film layer. includes elemental metals such as cobalt, nickel, and iron, as well as their alloys or oxides, and Co-Ps Co-Ni.
- It is formed by vacuum deposition of a commonly used ferromagnetic material such as P.

〔Example〕

Next, embodiments of the invention will be described.

Example 1 Using the vacuum evaporation apparatus shown in FIG.
Cobalt 14 was moved along the circumferential side of the cylindrical can 5 via guide rolls 10 and 9, and set to be wound up on a take-up roll 12 via guide rolls 10 and 11, and cobalt 14 was set in the ferromagnetic material evaporation source 13. . Next, the inside of the vacuum chamber 1 was evacuated to 5×10″5 torr using the exhaust systems 3 and 4, and the cobalt 14 was heated and evaporated, and the polyester film 6 was run at a speed of 10 m/min.
The temperature of guide rolls 10 and 11 is -10°C to 80°C.
A thin ferromagnetic metal 11 made of cobalt having a thickness of 1000 mm is deposited on the polyester film 6 by vacuum deposition with various adjustments within the range of . ! formed a layer. Afterwards, this was cut to a predetermined width to make magnetic tape. In addition, both Gai and Troll 8.9.10.11 have a surface roughness of 0. An IS with a diameter of 4 cm was used.

Example 2 A magnetic tape was produced in the same manner as in Example 1, except that in implementation pIJ 1, a guide roll 10 with a surface roughness of Q and Is and a diameter of 16 cm was used instead of the guide roll lO with a diameter of 4 cm. It was.

Example 3 The procedure was the same as in Example 1, except that the running speed of the polyester film 6 was changed from 10 m/min to 20 m/min, and the cobalt deposition speed was changed to match the running speed of the polyester film 60. I made magnetic tape.

Example 4 In Example 1, the temperature of guide rolls 10 and 11 was not adjusted, and instead of these guide rolls, the temperature of guide rolls 8 and 9 was adjusted variously within the range of -10°C to 80°C. A magnetic tape was made in the same manner as in Example 1.

Example 5 A magnetic tape was produced in the same manner as in Example 1, except that the temperatures of guide rolls 8 and 9 were also varied within the range of -10°C to 80°C.

Comparative Example 1 A magnetic tape was produced in the same manner as in Example 1 except that the temperature adjustment of guide rolls 10 and 11 was omitted, and the total length of wrinkles per 100 m was 1.2 m. 1.2-0.5 m~1.
It was 2+0.8 m.

The total wrinkle length per 100 m was determined for the magnetic tape obtained in each example. Figure 2.

Figure 6 shows the total wrinkle length obtained in this way,
Figure 2 shows the results obtained in Example 1, Figure 3 shows the results obtained in Example 2, and Figure 4 shows the results obtained in Example 2. 3
FIG. 5 shows the results obtained in Example 4, and FIG. 6 shows the results obtained in Example 5.

〔Effect of the invention〕

As is clear from FIGS. 2 to 6, conventional magnetic tapes often have wrinkles, whereas the magnetic tape of the present invention obtained by heating and adjusting the surface temperature of the guide roll to 15°C or higher ( 2 to 6), the generation of wrinkles is effectively suppressed. Therefore, according to the manufacturing method of the present invention, the generation of wrinkles is extremely well suppressed, and the wrinkle-free magnetic It can be seen that a recording medium is obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a vacuum evaporation apparatus used to carry out the manufacturing method of the present invention, and FIGS. 2 to 6 show 100% of the magnetic tape obtained in Examples 1 to 5.
It is a graph showing what the total wrinkle length per m is plotted against the surface temperature of the guide roll. 1... Vacuum chamber, 5... Cylindrical can, 6... Substrate, 8.9.10.11... Guide roll, 13...
Ferromagnetic material evaporation source, 14...Ferromagnetic material Fig. 1 Fig. 2 Guide roll surface temperature (0c) Fig. 4 Guide roll table 111111i1 degree (0c) Fig. 5

Claims (1)

[Claims] 1. In a vacuum atmosphere, the surface temperature of the guide roll that guides the substrate to move along the substrate support is set to 15℃.
The temperature is adjusted to above, and a ferromagnetic metal thin film layer is formed by directing a vapor flow of ferromagnetic material from a ferromagnetic material evaporation source onto the substrate, which is guided by the guide rolls and moves along the substrate support. A method for manufacturing a magnetic recording medium characterized by forming