JPH01165031A - Manufacture of magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a magnetic film medium having no wrinkles by sequentially contacting a high polymer substrate with a rotary drum from a central part to a peripheral part with respect to the direction of the width of the substrate at the time of contacting the high polymer substrate to the rotary drum. CONSTITUTION:The high polymer substrate 1 is brought into contacts with the rotary drum 2 through a roller 12 having a central part with a diameter of 63mm and end part with a diameter of 65mm and a concave bobbin form made of aluminum. At this time, the substrate 1 is sequentially contacted to the rotary drum 2 from the central part to the peripheral part with respect to the direction of the width of the substrate 1. The wrinkles of the substrate 1 are generated according to the friction of the drum 2 and the substrate 1. According to this method, at the time of starting to form the wrinkles, both the sides of the wrinkles are not simultaneously fixed but one side thereof sequentially contacts the drum 2, so that the substrate 1 contacts along the drum 2 to prevent the wrinkles.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a magnetic recording medium in which a magnetic thin film mainly composed of Go and Cr is formed on a polymer substrate by a vacuum evaporation method or a sputtering method. More specifically, the present invention relates to a method for manufacturing a magnetic recording medium that prevents wrinkles that occur when a polymer substrate comes into contact with a rotating drum.

[Conventional technology]

The perpendicular magnetic recording method is known as a recording method that provides high recording density. Media used in this recording method include Go-Cr'ai thin films, o-Ni-P plating films, and those coated with Ba-ferrite magnetic powder. Among them, Co-Cr 81 thin films have excellent recording properties. It has regenerative properties.

There are vacuum evaporation methods and sputtering methods for producing Go--Cr magnetic thin films, each of which has its own characteristics. Although the vacuum deposition method has a very high film formation rate.

A high substrate temperature is required to increase the coercive force Hcl in the direction perpendicular to the substrate. Although the sputtering method can obtain a sufficient coercive force Hcl at a lower substrate temperature than the vacuum evaporation method, the film formation rate is lower.From the viewpoint of mass production, the vacuum evaporation method can be said to be a method suitable for producing a Go-Or magnetic thin film.

However, no matter which production method is used, when the polymer substrate comes into contact with the rotating drum, in the production of the Co-Cr magnetic thin film,
There was a problem of wrinkles, which will be explained below.

Go-IO by vacuum evaporation method or sputtering method
The most common method for producing a magnetic thin film is to form the film while moving a polymer substrate along a rotating drum. FIG. 7 shows a schematic diagram of such a magnetic layer forming apparatus. A vacuum evaporation device or a sputtering device is used as the magnetic layer forming device, and the sputtering device has the same structure as the vacuum evaporation device except that the evaporation source 8 is replaced with a sputtering target. Polymer substrate 1
is a 0-rotation drum 2 that runs along the circumferential surface of the rotating drum 2.
The surrounding surface temperature can be set to any value up to 300°C. The Go and Cr atoms evaporated from the evaporation source 8 or the Co and Cr atoms sputtered from the sputtering target 8 have their incident angles restricted by the mask 7 and adhere to the polymer substrate 1 to form a magnetic thin film.

The coercive force Hcl of the thus obtained Go-Or magnetic thin film in the direction perpendicular to the substrate increases as the substrate temperature during film formation increases. Here, the substrate temperature is the temperature of the circumferential surface of the rotating drum. For practical purposes, at most 4006 e of HCl is required, but for this purpose the substrate temperature must be 80°C or higher for vapor deposition and 50°C or higher for sputtering.
As the substrate, a film made of polyethylene terephthalate, polyimide, or aramid is suitable from the viewpoint of mass production and dimensional stability.

However, when such a film is used to form a film at a circumferential temperature of the rotating drum of 80° C. or higher, when the polymer substrate 1 comes into contact with the rotating drum 2, the temperature of the rotating drum 2 is so high that the substrate l suddenly When gas is released from the substrate 1 at the surface in contact with the 0-rotation drum, which causes gas release from the substrate and thermal deformation of the substrate, a gap is created between the substrate 1 and the drum 2, which causes wrinkles and Moreover, the thermal deformation of the substrate is transported as it is and becomes wrinkles on the rotating drum.

The occurrence of such wrinkles occurs when the surface temperature of the rotating drum is 80°C.
This phenomenon is more likely to occur when the thickness of the polymer substrate is more than 10 scales, and it becomes more noticeable as the thickness of the polymer substrate becomes smaller, especially when the thickness of the polymer substrate is less than 10 scales. Conventionally, methods such as a nip roller, a preheating roller, or heating with a halogen lamp on the preheating roller have been used to prevent wrinkles. However, studies by the present inventors have revealed that these methods are also insufficient. FIGS. 8 and 9 show the configuration of the above method. In other words, the nip roller 9 in FIG. 8 tries to prevent wrinkles by pressing the substrate 1 when it comes into contact with the rotating drum 2, but if the temperature of the rotating drum is high, even if it presses the substrate 1, wrinkles will not occur. The preheating roller 10 shown in FIG.
In this case, if the temperature of the rotating drum increases, the temperature of the preheating roller 10 must also increase, resulting in wrinkles on the preheating roller. Further, even if the film was heated with a halogen lamp 11 on a preheating roller, wrinkles that had once occurred were hardly improved.

As described above, in the conventional configuration, when depositing a Go-Orr magnetic thin film or forming a film by sputtering,
There was a problem in that the polymer substrate wrinkled on the rotating drum, making it unusable as a magnetic recording medium.

[Problem that the invention seeks to solve]

The present invention solves the above-mentioned problems and aims to provide a method for manufacturing a good wrinkle-free Co--Cr magnetic recording medium.

[Means for solving problems]

In the present invention, a polymer substrate is conveyed along a rotating drum heated to 80° C. or higher, and a magnetic layer mainly composed of Co and Cr is formed on the polymer substrate on the rotating drum by vacuum evaporation or sputtering. A method for producing a magnetic recording medium obtained by manufacturing a magnetic recording medium, characterized in that when the polymer substrate comes into contact with the rotating drum, the polymer substrate comes into contact with the rotating drum sequentially from the center to the periphery in the width direction of the substrate. By using the method of the present invention, a wrinkle-free magnetic recording medium can be obtained. When the polymer substrate contacts the rotating drum, in order to contact the rotating drum sequentially from the center to the periphery in the width direction of the substrate,
A guide having a concave center portion is installed on the transport path of the substrate at a position immediately in front of the drum on the side where the substrate surface contacts the rotating drum. This guide may be a rotating roller or a fixed rod.

The present invention will be explained below using the figures.

FIG. 1 is a front view of the inside of a magnetic layer forming apparatus showing one embodiment of the present invention. l is a polymer base, 2 is a rotating drum, 3
is a delivery roller, 4 is a take-up roller, and 5 and 6 are free rollers. 7 is a mask that limits the incident angle of evaporated atoms, 8 is an evaporation source, and 12 is a thread-type free roller in which the diameter of the center portion of the roller is smaller than the diameter of the end portions.

FIG. 2 shows the portion from the thread-type concave free roller 12 to the rotating drum 2. As shown in FIG.

With the above configuration, when the polymer substrate 1 comes into contact with the rotating drum 2, it comes into contact with the rotating drum 2 sequentially from the center toward the peripheral portion in the width direction of the substrate 1. This will be explained in detail as follows. In the conventional method, when the polymer substrate 1 comes into contact with the rotating drum 2, when wrinkles begin to form, both sides of the wrinkles are exposed to the rotating drum 2, as shown in FIG.
The polymer substrate 1 is in contact with the substrate 1, so that the wrinkles are fixed by the friction between the rotating drum 2 and the substrate 1, and the substrate is conveyed on the rotating drum. On the other hand, with the structure of the present invention, when wrinkles begin to form, both sides of the wrinkles are not fixed at the same time, but one side of the wrinkles contacts the rotating drum 2 sequentially, so that the substrate l rotates. It comes into contact with the drum 2 and can prevent wrinkles.

〔Example〕

Next, the present invention will be explained in more detail using examples.

Example 1 An aluminum roller with a length of 200 mm, a diameter of 85 m at the ends, and a diameter of 631 m at the center was installed as a concave free roller.

I [80 mm, thickness 7.5 μs, 9
JL11, using a 12.5 μs polyimide film,
A Co-Or magnetic thin film having a thickness of 0.4 μs was deposited on the polyimide film L at a peripheral surface temperature of the rotating drum of 240° C. The polyimide film did not wrinkle when it came into contact with the rotating drum 2, and there were no wrinkles in the obtained magnetic thin film, and the coercive force Hc in the direction perpendicular to the film surface was 8000e.
Met.

Embodiment 2 As shown in FIG. 5, a curved bar 13 is mounted on a rotating drum 2.
It was installed on the conveyance path located just in front of.

The bar 13 is made of aluminum, has a length of 200 mm, a layer of 10 m in diameter, and is bent in a concave shape at the center by 1 inch with respect to the ends. The surface of the bar 13 is coated with a fluororesin to reduce the frictional force when the polymer base l contacts the concave portion of the bar 13.

An aramid film with a width of 80 cm, a thickness of 6 μs, and 12 mm was used as the polymer substrate, and the peripheral surface temperature of the rotating drum was set to 2.
0.4 thickness of Co-
A Cr magnetic thin film was deposited. No wrinkles were generated in the aramid film when it came into contact with the rotating drum 2, and there were no wrinkles in the obtained magnetic thin film. Also, what is the coercive force Hci in the direction perpendicular to the film surface? It was 000e.

Example 3 As shown in FIG. 6, a free roller 14 having a smaller diameter at its center than at its ends was installed on a conveyance path located immediately in front of the rotating drum 2. The free roller 14 is made of aluminum and has a total length of 200 mm and a diameter of 85 mm, and the small diameter portion at the center has a length of 70 mm and a diameter of 83 mm.

A PET film with a width of 80 m and a thickness of 7 and 10 μs was used as the polymer substrate l, and a permalloy layer with a thickness of 0.4 u was placed on the PET film with the circumferential temperature of the rotating drum set at room temperature.
Next, the surrounding surface temperature was set to 90°, and the Co-C with a thickness of 0.2 tiles was
The r layer was formed by sputtering.

No wrinkles were generated in the PET film when it came into contact with the rotating drum 2, and there were no wrinkles in the obtained magnetic thin film. In addition, the coercive force HCL in the direction perpendicular to the film surface of Go-Or tlI
It was 8000e.

〔Effect of the invention〕

According to the method of the present invention, when the polymer substrate comes into contact with the rotating drum, by installing guides so as to contact the rotating drum sequentially from the center to the periphery in the width direction of the substrate,
Conventionally, wrinkles that occur when a polymer substrate comes into contact with a rotating drum when depositing a magnetic thin film containing CO and Cr as main components on a polymer substrate or when forming a film by sputtering can be removed. It is possible to obtain a magnetic thin film medium free of .

[Brief explanation of the drawing]

Figure 1 is a front view of the inside of the magnetic layer forming apparatus of the present invention, Figure 2 is a perspective view of the rotating drum section inside the magnetic layer forming apparatus used in the present invention, and Figures 3.4 are wrinkles on the rotating drum. 5.6 is a perspective view of the rotating drum inside the magnetic layer forming apparatus showing the guide used in the present invention, and FIG. 7.8.9 is a sectional view of the polymer substrate to show the situation of Co- FIG. 2 is a front view of the inside of a conventional magnetic layer forming apparatus for producing an 0r magnetic thin film. 1 is a polymer substrate, 2 is a rotating drum, 3 is a delivery roller, 4 is a take-up roller, 5 and 6 are free rollers, 7 is a mask, 8 is an evaporation source or sputtering target,
9 is a nip roller, 10 is a preheating roller, 11 is a halogen lamp, 12 is a thread-type roller, 13 is a bar, and 14 is another deformation roller. Patent applicant Canon Co., Ltd. Representative Tadashi Wakabayashi Figure 3
M4 figure

Claims (1)

[Claims] 1) A polymer substrate is conveyed along a rotating drum heated to 80° C. or higher, and a magnetic layer mainly composed of Co and Cr is formed on the polymer substrate on the rotating drum by vacuum evaporation or sputtering. In the method for manufacturing the obtained magnetic recording medium, the polymer substrate is brought into contact with the rotating drum sequentially from the center to the periphery in the width direction of the substrate. Production method.