JPH01258226A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain the magnetic recording medium having an excellent traveling property and electromagnetic conversion characteristics by blowing gas to the high incident side and/or low incident side of the vapor flow of magnetic material particles and forming diagonal columnar parts and perpendicular columnar parts in a columnar structure. CONSTITUTION:A vapor source 9 consisting of Co-2ONi; in a crucible 8 below a cylindri cal can roll 6 is evaporated by heating and while the incident angle of the vapor flow 11 is controlled to 90-50 deg. by using protective plates 10a, 10b, the magnetic layer is formed on a substrate 4 delivered from a delivery roll 3 in a vacuum vessel 2 the inside of which is evacuated by a vacuum system 1. The magnetic layer having a required surface shape is formed by adjusting the rate and direction of the gas to be blown to the vapor flow 11 at the time of diagonal vapor deposition. The magnetic film having the projecting part which is nearly the same as the shape of a perpendicu larly vapor deposited film on the surface can be formed while the formed film is the diagonally vapor deposited film which allows high-density recording; therefore, the magnetic recording medium having the excellent traveling property and head touch is obtd. regardless of the traveling direction of a magnetic head. The S/N of color signals is improved if the parts near the peaks of the columnar particles are risen and the diagonal columnar parts are decreased.

Description

[Detailed description of the invention] [Industrial use! PF1 The present invention relates to a method of manufacturing a magnetic recording medium. More specifically, the present invention relates to a method for manufacturing a magnetic recording medium in which a magnetic layer having a columnar structure is formed by a continuous oblique M-striking method, and the columnar structure is composed of an oblique columnar portion and a vertical columnar portion.

[Prior Art] So-called non-binder type magnetic recording media, in which a magnetic thin film is formed by physical vapor deposition of magnetic particles on a non-magnetic substrate, have excellent electromagnetic conversion characteristics in the short wavelength region, so they can be used at high density. Suitable for recording purposes.

In order to function as a high-density recording medium, it is preferable to increase the smoothness of the medium surface and reduce spacing loss as much as possible. However, if the medium surface is made too flat, the magnetic head will have poor contact and running performance.

As a means to solve this problem, Japanese Patent Laid-Open No. 59-924
No. 28 proposes a magnetic recording medium in which a ferromagnetic thin film is formed on a plastic film surface provided with an underlayer having particle projections.

In the medium disclosed in this publication, F having particulate protrusions is used.
When magnetic particles are superimposed and vapor-deposited on the surface of the plastic film provided with the base layer, convex portions corresponding to the protrusion shapes of the base layer are formed on the surface of the magnetic layer.

[Problems to be Solved by the Invention] However, when magnetic particles are obliquely deposited, as shown in FIG. Instead, an irregularly shaped convex portion having a gentle slope portion A and a steep slope portion B is formed.

When the magnetic head runs from a gentle slope direction to a steep slope direction, the effect of improving running performance originally brought about by the shape of the protrusions of the underlayer is not so noticeable. Conversely, when the head runs from a steep slope direction to a gentle slope direction, the head gets caught on the steep slope, causing deterioration of durability.

Therefore, when magnetic particles are deposited obliquely on the surface of a plastic film provided with an underlayer having particulate protrusions, the head touch and runnability are not affected as much as when they are deposited vertically.

Compared to the eastward deposited magnetic film, the obliquely deposited magnetic film is more suitable for forming an in-plane recording film capable of high-density recording.

This invention solves the drawback of the prior art described in -1 U, which is the disorder of the protrusion shape on the surface of the magnetic layer that occurs when magnetic particles are deposited by the oblique deposition method, and improves runnability and durability. Another object of the present invention is to provide a magnetic recording medium with excellent electromagnetic conversion characteristics and a method for manufacturing the same.

[Means for Solving the Problems] As a result of extensive research and experiments carried out by the present inventor over many years, it was found that when a columnar structure magnetic layer of magnetic particles is formed on a non-magnetic substrate i- by a continuous oblique evaporation method, the above-mentioned By blowing gas on the high incidence side and/or the low incidence side of the vapor flow of magnetic particles, the above-mentioned drawbacks of the prior art are overcome by forming oblique columnar portions and vertical columnar portions in the columnar structure. It was discovered that The present invention was completed based on this knowledge.

Preferably, the oblique columnar portion is formed closer to the base of the columnar structure, and the vertical columnar portion is formed closer to the top.

Although the substrate in the magnetic recording medium of the present invention may be a smooth substrate, substrates having protrusions of various shapes on the surface are particularly preferred.

[Function] When a magnetic film of magnetic particles having a columnar structure consisting of an oblique columnar portion and a vertical columnar portion is laminated on a substrate having such protrusions, when the vertices of the vertical columnar portions are connected, the shape of the protrusion below will change. A convex portion having approximately the same shape is formed.

In this way, although it is an obliquely deposited film, it is possible to form a magnetic film that has convex portions on its surface that are approximately the same shape as those of a vertically deposited film.

Furthermore, regardless of the presence or absence of protrusions on the surface of the substrate, it can be expected that the color signal S/N will be improved by raising the top portion of the columnar particles by ~γ and reducing the diagonal columnar portions.

[Example] Hereinafter, specific examples of the present invention will be described in more detail with reference to the drawings.

FIG. 1 shows an example of a continuous oblique evaporation apparatus used for manufacturing the magnetic recording medium of the present invention, where J<a4.

In the vacuum chamber 2 evacuated by the vacuum system 1, the substrate 4 sent out from the delivery roll 3 moves along the cylindrical can roll 6 via the guide roll 5, and is wound up again via the guide roll 5. It is wound up on roll 7. At this time, a crucible 8 placed under the cylindrical can roll 6
The evaporation source 9 made of Co-2ONi set in the interior is heated and evaporated, and the Co-
A magnetic layer of Co--2ONi with a thickness of 1500 layers is formed on the substrate 4 at a deposition rate of 600 layers/sec while regulating the incident angle of the 2ONi vapor flow 11 within the range of 90 to 50''.

A polyethylene terephthalate film with a thickness of 9 μm and having 10 6 protrusions/mta2 with an average diameter of about 500 on the surface was used as the substrate.

Actual 1j1- As shown in FIG. 2(a), a cylindrical can roll 6
C incident on the substrate 4 moving along.

The gas Suita [
] 12 to produce magnetic recording media by spraying Ar gas in various flows M.

As shown in FIG. 2(b), the cylindrical can roll 6
C incident on the substrate 4 moving along.

Magnetic recording media were fabricated by spraying Ar gas at various flow rates from the gas outlet 13 onto the high incidence angle portion B of the -2ONi vapor flow 11.

Support Gosho 1 As shown in Figure 2 (C), cylindrical can roll 6
C incident on the substrate 4 moving along.

Low incidence angle part A and high incidence angle part B of vapor flow 11 of -2ONi
A of various flow rates from the gas outlet 12 and 13, respectively.
A magnetic recording medium was produced by spraying r gas.

FIG. 3(a) shows a cross section of the magnetic recording medium manufactured by blowing gas to the low incident angle portion of the vapor flow in Example 1.
). As shown in the figure, as the columnar structure of the magnetic particles 20 is raised toward the top, the oblique component decreases and the structure becomes closer to a vertical columnar structure.

FIG. 3(b) is a cross-sectional view of the magnetic recording medium manufactured in Example 2. The gas is blown to the high incidence angle part of the magnetic vapor flow, and the base of the columnar structure has a flattened shape, while the top has a vertically sitted shape.

FIG. 3(C) is a cross-sectional view of the magnetic recording medium manufactured in Example 3. Gas is blown into the low incidence angle and high incidence angle parts of the magnetic vapor flow, and the base of the columnar structure is raised up, and the top is also tilted 8 degrees, making the columnar structure look like an S-shape. It will look like this.

When there are protrusions 14 on the surface of the base 4, magnetic particles J'20
As shown in FIG. 4, a convex portion is formed corresponding to the position and shape of the protrusion. This is shown in Figure 3 (a)-(
It is equally formed by magnetic particles having any of the columnar structures shown in C). The width near the top of the columnar structure is 11″1′
I think it's because he's being blown away by the cane.

As a result of observing the surface shape, it was confirmed that in all Examples, the larger the gas flow, the more the surface shape of the magnetic layer could be obtained, which was closer to the surface shape of the base film.

In this way, by adjusting the bottle and direction of the gas that is blown onto the vapor flow of magnetic particles during oblique deposition, it is possible to easily form a magnetic layer with the required surface shape on base films of various shapes. can get.

If the gas flow rate is increased, the rise of the columnar structure will also be increased. As a general indicator, the gas flow rate is 200-100
It is within the range of 0J/win. In the case of 200 J/win droplets, the columnar structure's elongation effect is negligible. −・
On the other hand, if it exceeds 1000 J/win, it becomes difficult to form a columnar structure due to turbulence in the vapor flow.

The gas used for spraying is not only Ar, but also nitrogen, helium,
It may be mixed with a gas such as 002, an ionized gas thereof, or an oxidizing gas such as oxygen, and the effect remains the same; a gas with a large amount of carbon has a large oxidizing effect.

The number and direction of gas blowing [-1 are not limited to those exemplified in the above embodiments. As long as the direction of the vapor flow of the magnetic particles can be changed, the number and direction of the spraying holes are not particularly limited, and the same columnar structure q] - effect can be obtained.

The lower the density of the vapor flow of magnetic particles, the greater the effect, but if the density is too low, it becomes difficult to control the shape.

Although the ratio of the gas flow rate to the deposition rate of magnetic particles is not an essential requirement of the present invention, it is generally 80%
Preferably, the ratio is in the range of 1 to 180:1.

The surface shape of each magnetic recording medium obtained in Examples 1 to 3 was observed using a scanning electron microscope (Hitachi Model 8520-LB), and the roughness of the magnetic layer surface was measured using a $1 type surface roughness meter. was determined as a1.

In each example, the total flow rate of the gas to be blown was 2001
FIG. 5 shows the measurement results of the surface roughness of the magnetic tapes obtained using the case of /win as a reference. gas flow rate,
It is understood that the surface roughness changes depending on the direction of spraying.

In this example, a polyethylene terephthalate film was used as the substrate, but any substrate that is generally used for continuous oblique vapor deposition can be used in the magnetic recording medium of the present invention.

In addition, the shape of the protrusions on the surface of the base is wrinkle-like, earthworm-like,
The method of the present invention can be used regardless of the shape or density as long as the shape can be formed on the surface of the substrate, such as grain compaction.

The magnetic material used for the evaporation source is not limited to CoNi, but also Co-Cr+ Co-Few Co-Mn5.
Co-Ti+ Ni-Cr, N1-Fee Ni-Fe
-Cr, Co-N1-Crq Cot Nie Fe
Any commonly used materials can be used.

Furthermore, the method of the present invention can be used for purposes other than forming magnetic layers. For example, the method of the present invention can be used in any case where a film such as a base layer or a protective layer is formed using a continuous oblique evaporation method.

[Effects of the Invention] As explained above, the magnetic recording medium obtained by the manufacturing method of the present invention has an obliquely deposited magnetic film suitable for forming an in-plane recording film capable of high-density recording. is formed by magnetic particles having a columnar structure consisting of an oblique columnar part and a straight columnar part.

If there is an overlapping columnar part near the top of the columnar structure, even if magnetic particles are obliquely deposited on a substrate with protrusions on the surface,
A convex portion having approximately the same shape as the protrusion of the knife is formed at a position corresponding to the position of the lower protrusion.

In this way, although it is an obliquely deposited film, it is possible to form a magnetic film that has convex portions on its surface that are approximately the same shape as those of a vertically deposited film. As a result, a magnetic recording medium that is independent of the running direction of the magnetic head and has excellent running properties and head touch can be obtained.

It was also confirmed that, regardless of the presence or absence of protrusions on the surface of the substrate, when the columnar particles were raised near the top and the oblique columnar portions were reduced, the color signal S/N was improved by about +1.0 dB.

[Brief explanation of the drawing]

FIG. 1 is a W1 haze diagram showing an example of a continuous oblique evaporation apparatus used for manufacturing the magnetic recording medium of the present invention, and FIG.
) to (C) are configuration diagrams showing the manner in which gas is sprayed onto the vapor flow of the magnetic material, and FIGS. 3(a) to (C) are cross-sectional views of the columnar structure formed on the smooth part of the base. , FIG. 4 is a cross-sectional view of the columnar structure formed on the protruding portion of the base,
Fig. 5 is a characteristic diagram showing the relationship between the surface roughness of the magnetic layer and the amount of gas sprayed, and Fig. 6 is a characteristic diagram showing the relationship between the surface roughness of the magnetic layer and the amount of gas sprayed. FIG. 2 is a cross-sectional view of a recording medium. DESCRIPTION OF SYMBOLS 1... Vacuum system, 2... Vacuum Sakaki, 3... Delivery roll, 4... Substrate, 5... Kite roll, 6... Can roll, 7... Winding roll, 8 ... Crucible, 9.
...Evaporation source, 10a.

Claims (3)

[Claims] (1) In a method for manufacturing a magnetic recording medium, which comprises forming a columnar structured magnetic layer of magnetic particles on a non-magnetic substrate by continuous oblique vapor deposition, 1. A method of manufacturing a magnetic recording medium, characterized in that a diagonal columnar portion and a vertical columnar portion are formed in the columnar structure by spraying gas on an incident side. (2) The method for manufacturing a magnetic recording medium according to claim (1), wherein the columnar structure has an oblique columnar portion closer to the base. (3) A magnetic layer in which protrusions are distributed on the surface of the nonmagnetic substrate, and magnetic particles having a columnar structure consisting of oblique columnar portions and vertical columnar portions have convex portions that follow the shape of the protrusions. 2. The method of manufacturing a magnetic recording medium according to claim 1, further comprising forming a surface.