JPS61214135A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To control the generation of creases of the titled medium by bringing a substrate after a ferromagnetic material is vapor-deposited on the substrate into contact with a guide roll immediately before a winding roll and winding the substrate on the guide roll. CONSTITUTION:When a substrate 4 after a ferromagnetic material is vapor- deposited on the substrate is wound by a winding roll 12, the substrate 4 is wound by the winding roll 12 while being pressed at appropriate contact pressure by a guide roll 11, even when the winding diameter of the winding roll 12 is changed. Moreover, the contact angle theta between the guide roll and the substrate 4 is not changed. Consequently, the generation of creases when the substrate 4 is wound by the winding roll 12 is effectively controlled and the creases taken in by the winding roll 12 is completely eliminated.

Description

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

[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 roll, or secondary electrons from the electron gun used to melt the ferromagnetic material. This may hinder the running of the board due to electrostatic charges, etc., which may cause wrinkles on the running board. Wrinkles are likely to occur because the diameter changes and the contact angle of the substrate changes.For this reason, it is necessary to improve the mechanical precision between each roll, or to moderate the surface roughness of the substrate and guide roll, and to improve the surface roughness of the substrate. Attempts are being made to suppress the occurrence of wrinkles by applying lubricant to the back surface, etc., to eliminate the unbalanced tension on the substrate, reduce the frictional force between the substrate and each roll, and the static electricity generated by this. However, it is still not possible to sufficiently suppress the occurrence of wrinkles, and in particular, these methods cannot effectively suppress wrinkles caused by changes in the winding diameter of the take-up roll.

[Summary of the invention]

In order to improve this drawback, this invention has made various studies in particular regarding the relationship between the take-up roll and the guide roll immediately before it, and as a result, the take-up roll is brought into contact with the guide roll immediately before it, and this guide roll If the substrate after material deposition is wound up while being sandwiched between the take-up rolls, the contact angle of the substrate in contact with the guide rolls will not change even if the winding diameter of the take-up rolls changes, and the substrate This was achieved by discovering that since the material is appropriately pressed against the take-up roll, the generation of wrinkles can be effectively suppressed, and wrinkles introduced into the take-up roll can be completely prevented. In a method for manufacturing a magnetic recording medium in which 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 continuously moved by a substrate moving support device, A guide roll immediately in front of the take-up roll that winds up the substrate after vapor deposition is brought into contact with the take-up roll, and the substrate after evaporation of the ferromagnetic material is wound up by this guide roll while being sandwiched between the take-up roll and the take-up roll. It is something to do.

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

Figure 1 shows a cross-sectional view of the vacuum evaporation apparatus,
is a vacuum chamber, and the inside of this vacuum chamber 1 is maintained in a vacuum by an exhaust system 2. 3 is a cylindrical can disposed in the center of the vacuum chamber 1, and a substrate 4 such as a polyester film is moved from a raw roll 5 to a guide roll 6 and a tension roll 7.
It moves along the circumferential surface of the cylindrical can 3 via a guide roll 8 and is wound up onto a take-up roll 12 via a guide roll 9, a tension roll 10, and a guide roll 11. During this time, the ferromagnetic material 14 is heated and evaporated by the ferromagnetic material evaporation source 13 disposed at the bottom of the vacuum chamber 1, facing the substrate 4 moving along the circumferential side of the cylindrical can 3, and this vapor flow is transferred to the substrate 4. 4 for vapor deposition.

Here, the guide roll 11 just before the take-up roll 12 is arranged so as to be in contact with the take-up roll 12, and the substrate 4 after the ferromagnetic material has been deposited is sandwiched between the take-up roll 12 by the guide roll 11. It is wound up on a winding roll 12. Further, the winding roll 12 is mounted so as to be movable left and right, and is adjusted so as to correspond to the winding diameter of the winding roll 12, which changes as the substrate 4 on which the ferromagnetic material has been deposited is wound up. Therefore, when the substrate 4 after ferromagnetic material deposition is wound around the take-up roll 12, even if the winding diameter of the take-up roll 12 changes, the substrate 4
The substrate 4 is always sandwiched between the guide rolls 11 and taken up by the take-up roll 12, and the contact angle θ of the substrate 4 in contact with the guide roll does not change, so when the substrate 4 is taken up by the take-up roll 12 The generation of wrinkles can be effectively suppressed, and wrinkles introduced into the take-up roll 12 can be completely prevented.

In this way, the contact pressure between the guide roll 11 and the take-up roll 12 when the guide roll 11 is brought into contact with the take-up roll 12 and the substrate 4 is taken up while being sandwiched therebetween is very small (but does not cause wrinkles). can be suppressed, but 0.
It is more preferable to clamp them at a pressure of 1 kg/cn1 or more, and a stronger contact pressure will completely prevent wrinkles from forming. However, if the contact pressure becomes too large, plastic deformation will occur in the substrate after the ferromagnetic material has been deposited, so the contact pressure is preferably within a range that does not cause plastic deformation in the substrate.

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, Co-P, 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 As shown in FIG. 1, a vacuum evaporation apparatus was used in which a guide roll 11 was placed in contact with a take-up roll 12, and the Young's modulus of a film having a thickness of 12μ was different as shown in Table 1 below. The polyester film 4 is moved along the circumferential side of the cylindrical can 3 from the raw roll 5 through the guide roll 6, tension roll 7, and guide roll 8, and then through the guide roll 9, tension roll 10, and guide roll 11. , the tension was 0.5 kg/co+ and the contact pressure was varied as shown in Table 1 below, and cobalt 14 was placed in the ferromagnetic material evaporation source 13 while being set to be wound on the winding roll 12. Next, the inside of the vacuum chamber 1 is evacuated to 5X10-5 Torr using the exhaust system 2, and the cobalt 14 is heated and evaporated to form a layer of 1.1 mm thick on the polyester film 4.
A ferromagnetic metal thin film layer made of cobalt was formed. Afterwards, this was cut to a predetermined width to make magnetic tape.

Comparative Example 1 As shown in FIG. 2, the same vacuum evaporation equipment as shown in FIG. A magnetic tape was produced in the same manner as in Example 1, except that the formed polyester film 4 was wound around the guide roll 11 and wound without being sandwiched between the rolls 2.

In Example 1 and Comparative Example 1, the presence or absence of wrinkles and plastic deformation of the substrate when it was wound up on a take-up roll were observed.

Table 1 below shows the results.

Table 1 [Effects of the Invention] As is clear from the above table, wrinkles were observed in Comparative Example 1, but no wrinkles were observed in Example 1. There is no plastic deformation of the substrate unless it is 2 or more, which shows that according to the manufacturing method of the present invention, the generation of wrinkles can be effectively suppressed and a wrinkle-free magnetic recording medium can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an example of a vacuum evaporation apparatus used to carry out the manufacturing method of the present invention, and FIG. 2 is a schematic sectional view of a conventional vacuum evaporation apparatus. ■... Vacuum chamber, 3... Cylindrical can, 4... Substrate, 5... Raw roll, 6.8.9.11... Guide roll, 12... Winding roll, 13...Ferromagnetic material evaporation source, 14...Ferromagnetic material patent applicant Hitachi Maxell Ltd. Figure 1 Figure 2

Claims (1)

[Claims] 1. A method for producing a magnetic recording medium in which a ferromagnetic material vapor flow is directed from a ferromagnetic material evaporation source onto a substrate that is continuously moved by a substrate moving support device in a vacuum chamber to form a ferromagnetic metal thin film layer. In this method, a guide roll just in front of the take-up roll for winding up the substrate on which the ferromagnetic material has been vapor-deposited is brought into contact with the guide roll, and the board on which the ferromagnetic material has been vapor-deposited is wound up while being sandwiched between the take-up roll and the guide roll. A method for manufacturing a magnetic recording medium characterized by