JPH0430644B2 - - Google Patents

Description

[Detailed Description of the Invention] Background Technical Field of the Invention Signal relates to a method of manufacturing a magnetic recording medium by flying a magnetic material, and more specifically, a method of manufacturing a magnetic recording medium with improved electromagnetic conversion characteristics, magnetic characteristics, and physical and chemical characteristics. Regarding the method. BACKGROUND TECHNOLOGY Methods for manufacturing magnetic recording media can be classified into two types, those using a coating method and those using a flying or plating method. By coating method (Hereinafter, magnetic recording media obtained by this method are referred to as coating-type magnetic recording media.)
In this method, a magnetic paint obtained by mixing and dispersing ferromagnetic powder such as γ-F ₂ O ₃ and Fe with an appropriate binder is applied onto a non-magnetic substrate, and subjected to treatments such as magnetic field orientation, drying, and super calendering. This gives it properties as a magnetic recording medium. This coated magnetic recording medium is aimed at increasing coercive force, improving recording density, and making the magnetic layer thinner. However, in the method of coating a magnetic paint obtained by mixing ferromagnetic powder with a binder on a non-magnetic substrate,
There is essentially a limit to the effective filling rate of ferromagnetic powder, which makes it difficult to aim for higher density and thinner films. For this reason, in order to achieve higher density and thinner films, a continuous thin film of magnetic material is usually deposited on a non-magnetic substrate by flying the magnetic material using methods such as vacuum evaporation, sputtering, and ion plating. A method of forming the magnetic recording medium and a method of forming it by electrolysis or chemical plating (hereinafter, magnetic recording media obtained by these methods are referred to as thin-film magnetic recording media) have been adopted. This thin-film magnetic recording medium provides a magnetic recording medium that has characteristics not found in the coating-type magnetic recording media, such as high density and thin film. However, thin-film magnetic recording media generally have physical and chemical properties such as corrosion resistance and abrasion resistance, magnetic properties such as residual magnetic flux density, squareness ratio, coercive force, output level,
Improvements in electromagnetic conversion characteristics such as output fluctuation and still durability are required. The physical, chemical, magnetic, and electromagnetic properties of magnetic thin films created by vacuum evaporation, sputtering, ion plating, etc. are determined by the angle of incidence of the flying magnetic material on the substrate surface, the degree of oxidation, the rate of magnetic layer formation, It depends on the energy of the incident particle, etc. For improving physical and chemical properties such as corrosion resistance and abrasion resistance, reactive vapor deposition technology using reactive gases such as oxygen is known, and for improving magnetic properties and electromagnetic conversion properties, Kosho 41−
Techniques such as so-called oblique evaporation described in No. 19389 are known. Furthermore, in reactive vapor deposition, JP-A-57-
No. 88531 discloses that supplying oxygen gas having a flow generally opposite to the running direction of the substrate is effective in improving the above-mentioned properties. Furthermore, in JP-A No. 58-45625, a mask for regulating the angle of incidence is used, and a reactive gas is ejected from the side of the mask facing the flying vapor flow of a magnetic material to form a thin film and provide corrosion resistance. It improves physical and chemical properties such as hardness and abrasion resistance, as well as magnetic properties such as control of holding force.
A technique has been proposed to make the electromagnetic conversion characteristics uniform in the width direction and length direction of a magnetic recording medium. This publication discloses a group of small holes as a reactive gas outlet. However, when a group of small holes is used as the ejection port, when the reactive gas is ejected, the flow of gas molecules ejected from the small holes is greatly disturbed, and the magnetic properties of the formed magnetic recording medium in the width direction become non-uniform. It was inevitable that it would happen. In particular, the closer the reactive gas outlet is provided to the surface of the non-magnetic substrate, the greater the influence of turbulence on the gas molecular flow, and the more pronounced the non-uniformity of the magnetic properties. On the other hand, as mentioned above, the various characteristics of a thin film magnetic recording medium are greatly influenced by the incident angle of the flying magnetic material, the degree of oxidation, the reaction state, etc. It is necessary to install the jet port so as to provide a steady flow and a predetermined angle of incidence, and it has been desired to improve the shape and installation conditions of the reactive gas jet port. Purpose of the Invention The present invention has been made to solve the above-mentioned problems, and the first purpose of the present invention is to improve corrosion resistance,
An object of the present invention is to provide a method for manufacturing a magnetic recording medium having excellent physical and chemical properties such as wear resistance. A second object of the present invention is to provide a method for manufacturing a magnetic recording medium with excellent magnetic properties and electromagnetic conversion properties. A third object of the present invention is to provide a method for manufacturing a magnetic recording medium having uniform electromagnetic conversion characteristics and magnetic characteristics in the width direction and length direction. The fourth object of the present invention is to have excellent quality reliability;
An object of the present invention is to provide a method for manufacturing a magnetic recording medium with high productivity. The above-mentioned object of the present invention is to provide a method for manufacturing a magnetic recording medium in which a magnetic layer is formed by flying a magnetic material onto a non-magnetic substrate. A method for manufacturing a magnetic recording medium, wherein a magnetic layer is formed on the substrate by injecting gas from a slit-like jet nozzle having a long side in the width direction of the substrate, wherein the gas from the slit-like jet nozzle is 3 from the non-magnetic substrate surface
The injected gas is injected from a distance of 15 mm to 15 mm, and the injected gas passes through a slit-shaped outlet from a tank integrally formed in the mask for regulating the flying air inflow angle, and reaches a distance of 140 mm with respect to the normal line erected on the non-magnetic substrate. This is achieved by a method for manufacturing a magnetic recording medium characterized by jetting at an angle of 180° to 180°. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a sectional view of a main part of an embodiment of an apparatus used in the method of manufacturing a magnetic recording medium of the present invention. The inside of this device is hermetically sealed from the outside air by a casing 1, and the inside of the casing 1 is divided by a separation wall 2 into a chamber for sending out and winding up a non-magnetic substrate 3 and a deposition chamber. An exhaust pipe 4 is provided at the bottom of the tank, and the exhaust pipe 4 is connected to a vacuum exhaust device 5. The delivery/winding chamber has a delivery shaft 6, two free rollers 7, a substrate support 8, and a winding shaft 9 as a substrate running system. The vapor deposition chamber includes an electron beam generator 10, a crucible 11, and a crucible 11 as a vapor deposition system.
There is a magnetic material 12 to be coated therein, and further,
A mask 13 is provided that projects into the flying space formed between the substrate support 8 and the crucible 11, and is designed to regulate the angle at which the flying airflow of the magnetic material 12 is incident on the substrate 3. The mask 13 has a hollow structure, and is provided with a slit-shaped jet nozzle 14 having a long side in the width direction of the substrate 3 set on the substrate support 8 in the vicinity of its incident angle regulating tip. Gas G is introduced from a gas introduction pipe 15 and is ejected from a slit-shaped ejection port 14 toward the substrate 3 at a predetermined angle. The jet nozzle 14 of the mask 13 according to the present invention has a slit shape, as shown in FIGS. 2a and 2b. The slit may have a slit shape as a whole, and for example, a plurality of partition plates or the like may be provided parallel to the short side of the slit. The formation position of the jet nozzle 14 may be in the vicinity of the incident angle regulating tip of the mask 13. For example, as shown in FIG. It may be provided on the surface of the mask 13 where the tip of the regulating portion is formed, as shown in FIG. here,
Preferably, it is the one shown in FIG. 2a. Furthermore, the jetting direction of the reactive gas determined by the installation conditions of the jetting port 14 is determined by the relationship between the normal to the substrate surface at the position where the jetting gas collides with the substrate 3 and the gas jetting direction, as shown in FIG. The angle θ formed is preferably 90° or more, more preferably 140° to 180°. Further, the distance between the jet nozzle 14 and the substrate surface is preferably 15 mm or less, more preferably 3 to 10 mm. Appropriate values for the speed and amount of ejected gas and the width of the slit in the ejection port 14 are determined in correlation, but the width of the slit is preferably 5 mm or less, and more preferably 0.5 to 5 mm.
2mm, and the speed and amount of ejected gas are determined by the slit width.
2×10 ^-2 to 0.5 P _a cm ³ /s per 10 cm is preferable,
More preferably 0.1 to 0.3P _a per 10cm slit width
cm ³ /s. At this time, in order to improve the uniformity of the speed and amount of the ejected gas, it is a preferred embodiment to provide a tank between the introduction pipe 15 and the introduction port, as this further enhances the effects of the present invention. In addition, although cooling mechanisms for the substrate support, mask, etc. are omitted, techniques known in the industry are used.
They can be used selectively as long as they do not reduce the effects of the present invention. Furthermore, although an electron beam heating method is used in the embodiment, methods such as resistance heating and laser beam heating may also be used. The reactive gas used in the present invention includes oxygen,
Any gas may be used as long as it contains at least one selected from oxygen allotropes and oxygen active species. Other gases that can be used in combination with the gas include, for example, nitrogen (N ₂ ).
gas, inert gases such as helium gas (He), xenon gas (Xe), radon gas (Rn), argon (Ar), neon (Ne), carbon monoxide (CO),
Carbon dioxide (CO ₂ ), hydrogen (H ₂ ), water vapor (H ₂ O)
They can be used alone or in combination of two or more. The magnetic material that can be used in the method for manufacturing a magnetic recording medium according to the present invention may be any conventionally used and known magnetic material, such as Fe,
Metal-based magnetic materials such as Ni and Co: Fe-Ni-Co alloy, Fe-Mn-Zn alloy, Fe-Ni-Zn alloy, Fe-
Co-Ni-Cr alloy, Fe-Co-Ni-P alloy, Co-
Examples include various magnetic materials such as alloy-based magnetic materials containing Fe, Ni, and Co as main components, such as Ni alloy. Examples of methods for forming a magnetic layer by flying a magnetic material onto a nonmagnetic substrate include well-known vacuum evaporation, sputtering, and ion plating methods. In other words, "flying" in the present invention refers to various types of vapor deposition (including reactive vapor deposition), sputtering, CVD (Chemical
This refers to the deposition of a material onto a support through a flying space using methods such as vapor deposition and ion plating. Materials for the non-magnetic substrate include polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, polyolefins such as polypropylene, cellulose derivatives such as cellulose triacetate and cellulose diacetate, plastics such as polycarbonate, Cu, Al,
Metals such as Zn can be used, as well as glass and so-called new ceramics (such as boron nitride,
silicon carbide, etc.) are used. A plurality of non-flexible substrates such as glass can be held on a flexible substrate to form a magnetic layer continuously.
The form of the substrate as the final magnetic recording medium may be tape, sheet, card, disk, drum, etc., and various materials are selected as necessary depending on the form. The thickness of these substrates is approximately 3 to 10 μm in the case of a film or sheet, preferably 5 to 50 μm, and 30 μm to 10 mm in the case of a disk or card.
That's about it. Further, the method for manufacturing a magnetic recording medium according to the present invention includes forming the above-described magnetic layer on a substrate for the purpose of improving slipperiness, preventing static electricity, preventing transfer, improving storage stability, and improving wear resistance of the magnetic recording medium. After and/or before formation, an overcoat layer or a backcoat layer may be provided, for example, by a known coating method, vapor deposition method, etc. These coating methods and vapor deposition methods are described, for example, in JP-A-54-123922, JP-A-54-123923, and JP-A-56-
No. 71284, No. 56-71286, No. 56-71287, No. 56
-11626 and 57-135442. Materials for these overcoat layers and backcoat layers include various polymers (for example, urethane resin epoxy resin, vinyl chloride-vinyl acetate copolymer, etc.), organic oligomers and polymers such as silicone resin, and inorganic materials such as carbon black and alumina. : Various materials such as low molecular weight organic compounds such as antioxidants such as phenol derivatives and singlet oxygen quenchers such as amine derivatives can be used, as well as various lubricants, abrasives, antistatic agents, dispersants, etc. Various ingredients can be added and used. Specific Examples of the Invention Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Example 1 A magnetic recording medium was manufactured using the apparatus shown in FIG. 1 and a mask having a slit-shaped reactive gas outlet shown in FIG. 2a under the following conditions. Slit width 1.0 mm, length 20 cm Gas jet angle θ = 170° Distance between jet nozzle and substrate 7.0 mm A 12.5 μm thick polyethylene terephthalate board was run at a speed of 50 m/min at a pressure of 7 × 10 ^-3 Pa. Meanwhile, Co-Ni (80-20) magnetic material is evaporated by electron beam heating, and oxygen gas is released.
2.5Kg/cm ² , spouted from the spout at 1.0/min,
A magnetic layer with a thickness of 0.15 μm was formed. The obtained original magnetic recording medium was cut into tapes having a width of 12.65 mm to obtain example tapes. The example tapes were formed at each position during thin film formation, that is, in the width direction, the tape formed at the midpoint of the slit-shaped jet nozzle, and the tape formed at a certain width direction distance from the midpoint, and in the longitudinal direction, the thin film was formed at each position. Approximately 2000m from the beginning of formation
The following magnetic properties were measured over the entire range. The properties of the above example tape, including coercive force, residual magnetic flux, still durability, and C/N at 5 MHz and 0.75 MHz, were investigated. The results are shown in Table 1 and Figures 4a, b, c. (The example tape is indicated by a.) The holding force and residual magnetic flux were measured using a vibrating sample magnetic recorder manufactured by Toshiba Industries, and the still durability was measured using a commercially available VHS machine. We measured the time it took for the value to decrease by 3db. C/N
is the value at a relative speed of head and tape of 3.75 m/sec.

[Table] * Shows the maximum value of fluctuation.
** Indicates the average value of dispersion (average deviation).
Comparative Example 1 The same conditions as in Example 1 were carried out, except that a group of 11 small holes each having a diameter of 1 mm and arranged at 2 cm intervals in the width direction was used as the ejection port. The characteristics of the obtained magnetic recording medium are shown in Table 1, Figure 4a,
Shown in b. (Comparative Example 1 tape is represented by b.) Comparative Example 2 Example 1 except that oxygen is not spouted from the spout.
It was carried out under the same conditions. The characteristics of the obtained magnetic recording medium are shown in FIG. 4c.
(Comparative Example 2 tape is represented by c.) Each of the characteristic curves in FIGS. 4a, b, and c is expressed as a relative percentage, with the maximum value of each of the example tape and comparative example tape being 100. From the results in Table 1, it can be seen that the Example tape had smaller fluctuation ranges in the width direction and longitudinal direction in each of the characteristics of 5MHz and 0.75MHz C/N ratio and still durability than Comparative Example 1 tape. Furthermore, from FIG. 4a, it can be seen that not only the variation in the width direction of the residual magnetic flux characteristic of the Example tape has expanded by more than 90%, but also the variation of small irregularities seen in the Comparative Example 1 tape has disappeared. . From FIG. 4b, the variation in the width direction of the coercive force characteristics of the example tape is 95% or more in almost the entire width, and Comparative Example 1
It can be seen that the fluctuation range is smaller than that of tape, which shows that it is superior. From FIG. 4c, it can be seen that the variation in the longitudinal direction of the holding force property of the example tape is much smaller than that of the comparative example 2 tape and is excellent. Example 2 A magnetic recording medium was manufactured under the same conditions as in Example 1 except that the distance between the ejection port and the substrate was 15.0 mm, and the characteristics tests were conducted in the same manner as in Example 1. The test results are shown in Table 2. Comparative Example 3 A reactive gas supply pipe having a slit-shaped reactive gas outlet shown in FIG. 2a is installed in the apparatus shown in FIG. 1 so that the outlet is located below the separation wall 2 and near the substrate. Then, the reactive gas was ejected toward the substrate from a newly installed ejection port instead of the ejection port 14. A magnetic recording medium was manufactured using this apparatus under the same conditions as in Example 1, except that the pressure was maintained at 1×10 ^-4 Torr, and the characteristics tests were conducted in the same manner as in Example 2. The test results are shown in Table 2.

[Table] In other words, according to the method of the example, the reactive gas is sprayed immediately after the estimation of the deposited atoms is completed, so an oxide layer is mainly formed on the surface of the magnetic thin film, which deteriorates the magnetic properties, electrical properties, and durability. An excellent magnetic recording medium can be obtained. On the other hand, in the method of the comparative example, in which reactive gas is sprayed from the start of estimating the deposited atoms, an oxide layer is formed uniformly over the entire thin film, and deterioration of various properties may appear. Recognize. Specific Effects of the Invention As is clear from the above results, according to the material method for a magnetic recording medium according to the present invention, the obtained magnetic recording medium has excellent physical, chemical properties, magnetic properties, and electromagnetic conversion properties. Moreover, the medium has uniform properties in the width direction and longitudinal direction, and is also excellent in quality reliability, productivity is improved, and is economically practical.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a cross-sectional view of a main part of an apparatus used in the method of manufacturing a magnetic recording medium of the present invention, and FIGS.
FIG. 3 is an explanatory diagram showing the ejection angle; FIG.
Figure b is the characteristic curve diagram of the variation distribution of coercive force in the width direction, and Figure 4c is the characteristic curve diagram of the variation distribution of coercive force in the longitudinal direction (Example tape...a, Comparative example 1 tape...b, Comparative example 2 Tape...c. 1... Casing, 3... Substrate, 6... Delivery shaft, 8... Substrate support, 9... Winding shaft, 10...
Electron beam generator, 11... Crucible, 13...
Mask, 14... spout, 15... reactive gas supply pipe.

Claims (1)

[Scope of Claims] 1. In a method of manufacturing a magnetic recording medium in which a magnetic layer is formed by flying a magnetic material onto a non-magnetic substrate, a method for manufacturing a magnetic recording medium in which a magnetic material flying magnetic material is integrally attached to an incident angle regulating tip of a mask for regulating an inflow and incidence angle of flying air. A method for manufacturing a magnetic recording medium, wherein a magnetic layer is formed on the substrate by injecting gas from a slit-like jet nozzle having a long side in the width direction of the substrate, wherein the gas from the slit-like jet nozzle is A method in which the gas is injected from a distance of 3 mm to 15 mm from the surface of the non-magnetic substrate, and the injected gas passes through a slit-shaped outlet from a tank integrally formed within the mask for regulating the flying air inflow angle, and is erected on the non-magnetic substrate. A method for manufacturing a magnetic recording medium, characterized in that jetting is performed at an angle of 140° to 180° with respect to a line. 2. The method of manufacturing a magnetic recording medium according to claim 1, wherein the gas is a gas containing at least one selected from oxygen, an allotrope of oxygen, and an active species of oxygen.