JPH0987840A - Magnetic recording medium and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a magnetic recording medium having a high output in a wide range by using a specified Fe-Ni alloy and forming a magnetic film having a specified composition ratio on a substrate. SOLUTION: A substrate 1 can be magnetic or nonmagnetic, however the nonmagnetic substrate is generally used. An olefinic resin, polymer, inorg. material and metallic material are exemplified. An Fe-Ni-N-O magnetic layer 21 is formed on the surface of the substrate 1, and a protective film 22 having about 10-200Å thickness is formed on the magnetic film 21. A lubricant layer 23 is formed on the protective film 22. A back coat layer 24 is formed on another side of the substrate 1. The magnetic film 21 contains, by atomic %, 40-80% Fe, 1-14% Ni, 5-40% N and 5-30% O, respectively as the element. A material to be plated in the vapor source to constitute the magnetic film 21 contains 1-17 atomic % Ni and the balance Fe with inevitable impurities. Consequently, a magnetic recording medium excellent in corrosion resistance is provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to Fe--Ni--N--
The present invention relates to a magnetic recording medium having an O-based metal magnetic film.

[0002]

A metal thin film type magnetic recording medium in which a magnetic film is formed by dry plating means such as vapor deposition or sputtering is widely known. There are various materials for forming the magnetic film. For example, Co-Ni and Co-Cr magnetic alloys have been mainly used so far.

However, Co, Ni, Cr, etc. are expensive. Because of this, attention has been paid to Fe. For example, Fe _1-XY N _X O _Y (however, 0.25 ≦ X + Y <
A magnetic recording medium having an iron oxynitride film of 0.60, X> Y) has been proposed (JP-A-61-54023).

This product has excellent magnetic properties, weather resistance and durability. However, the high reproduction output in the high range is not obtained. Further, in recent years, use has been increasing in more severe environments, and further corrosion resistance is required. Therefore, an object of the present invention is to provide a magnetic recording medium which can obtain a high reproduction output from a low range to a high range, is excellent in electromagnetic conversion characteristics, and is excellent in corrosion resistance.

[0005]

The object of the present invention is to provide N
i is 1 to 17 at. %, The balance being unavoidable impurities and an Fe—Ni-based alloy of Fe is used, and a magnetic film of Fe—Ni—N—O type is provided on a support. The ratio of Fe is 40 to 80 at. %,
The ratio of Ni in the magnetic film is 1 to 14 at. %, The ratio of N in the magnetic film is 5 to 40 at. %, The proportion of O in the magnetic film is 5 to 30 at. % Of the magnetic recording medium.

Particularly, Ni is 2 to 15 at. %, The balance being unavoidable impurities and an Fe—Ni based alloy of Fe is used, and a magnetic recording medium in which a Fe—Ni—N—O based magnetic film is provided on a support by an ion assisted deposition method,
The ratio of Fe in the magnetic film is 40 to 80 at. %, The ratio of Ni in the magnetic film is 1 to 14 at. %, The ratio of N in the magnetic film is 5 to 40 at. %, The proportion of O in the magnetic film is 5 to 30 at. %, The ratio of N in the magnetic film is O
Is achieved by a magnetic recording medium.

Further, Fe is 40 to 80 at. %, Ni is 1
~ 14 at. %, N is 5 to 40 at. %, O is 5 to 30
at. % Fe—Ni—N—O type magnetic film is provided, wherein said Fe—Ni—
Ni as a material to be placed in the evaporation source in order to form a -NO magnetic system is 1 to 17 at. %, The balance being unavoidable impurities and an Fe—Ni based alloy of Fe is used, and the Fe—Ni—N—O based magnetic film is formed by an ion assisted vapor deposition method. This is achieved by the manufacturing method.

In particular, Fe is 40 to 80 at. %, Ni is 1 to 14 at. %, N is 5 to 40 at. %, O is 5 to 3
0 at. %, And a Fe—Ni—N—O based magnetic film in which the proportion of N is higher than the proportion of O. A Fe—Ni—N—O based magnetic film is provided. 2 to 15 at.% Ni as a material to be placed in the evaporation source in order to form the magnetic film. %, The rest are inevitable impurities and Fe
Fe-Ni based alloy is used, and the Fe-Ni-N-O based magnetic film is formed by an ion assisted vapor deposition method.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The magnetic recording medium of the present invention contains 1 to 17 at. %, The rest are inevitable impurities and Fe of Fe
A magnetic recording medium comprising a support and a Fe—Ni—N—O magnetic film formed of a —Ni alloy,
The ratio of Fe in the magnetic film is 40 to 80 at. %, The ratio of Ni in the magnetic film is 1 to 14 at. %, The ratio of N in the magnetic film is 5 to 40 at. %, The proportion of O in the magnetic film is 5 to 30 at. % Is satisfied. In particular, N
i is 1 to 17 at. %, The balance being unavoidable impurities and an Fe—Ni based alloy of Fe is used, and a magnetic recording medium in which a Fe—Ni—N—O based magnetic film is provided on a support by an ion assisted deposition method, The ratio of Fe in the magnetic film is 40 to 80 at. %, The ratio of Ni in the magnetic film is 1 to 14 at. %, The ratio of N in the magnetic film is 5 to 4
0 at. %, The proportion of O in the magnetic film is 5 to 30 at.
% Is satisfied. Further, Ni is 2 to 15 at. %,
The rest are unavoidable impurities and Fe—Ni based alloys of Fe are used, and Fe—Ni—N—O is formed by the ion assisted vapor deposition method.
A magnetic recording medium comprising a support and a magnetic film of a series of 40 at. % ≦ Fe ratio in the magnetic film ≦ 8
0 at. %, 1 at. % ≤ Ni ratio in the magnetic film ≤
14 at. %, 5 at. % <Ratio of N in the magnetic film ≤
40 at. %, 5 at. % ≦ O ratio in the magnetic film ≦
30 at. %, The ratio of O in the magnetic film <the ratio of N in the magnetic film.

The method of manufacturing the magnetic recording medium of the present invention is
Fe is 40 to 80 at. %, Ni is 1 to 14 at. %,
N is 5 to 40 at. %, O is 5 to 30 at. % Fe-
A method of manufacturing a magnetic recording medium provided with a Ni—N—O based magnetic film, wherein Ni is used as a material placed in an evaporation source to form the Fe—Ni—N—O based magnetic film. Is 1 to 17 at. %, The rest are inevitable impurities and Fe of Fe
A —Ni-based alloy is used, and the Fe—Ni—N—O-based magnetic film is formed by an ion assisted deposition method. In particular, 40 at. % ≦ Fe ratio in magnetic film ≦ 80
at. %, 1 at. % ≦ Ni ratio in magnetic film ≦ 14a
t. %, 5 at. % <Ratio of N in magnetic film ≤ 40 at.
%, 5 at. % ≦ O ratio in magnetic film ≦ 30 at. %,
Fe satisfying the ratio of O in the magnetic film ≦ the ratio of N in the magnetic film
A method of manufacturing a magnetic recording medium provided with a —Ni—N—O based magnetic film, wherein a material placed in an evaporation source for forming the Fe—Ni—N—O based magnetic film Ni
Is 2 to 15 at. %, The rest are inevitable impurities and Fe F
An e-Ni based alloy is used, and the Fe-Ni-N-O based magnetic film is formed by an ion assisted deposition method.

The magnetic recording medium of the present invention will be described as follows, for example, by using an evaporation method with a high film formation rate as an example. First, for example, Fe + Ni is 95 to 9 in all metal components.
8.5 wt% (so-called purity is 95 to 98.5 wt%),
The total amount of Au, Pt, and Ag is 0 to 0.05 wt% (It is good that it is 0, but it may be contained as an unavoidable impurity to some extent. The total amount of Ag is as small as possible, for example 0.0
A Fe + Ni-based alloy (Fe + Ni alloy) material, which is 5 wt% or less) and the rest is other metal components (eg, Co, Mn, Cr, etc.), is put into the crucible of the oblique vapor deposition apparatus. The reason why the alloy material having such a purity (95 to 98.5 wt%) is used is that it is much cheaper than the case where a high-purity alloy material having a purity of 99.95 wt% or more is used. It should be noted that the use of a high-purity material having a purity of 98.5 wt% or more is not excluded. Then, the inside of the oblique vapor deposition apparatus is evacuated to a predetermined vacuum degree, the Fe—Ni alloy material is evaporated by an electron gun or other means, and the Fe—Ni alloy particles are attached and deposited on the running support. During this attachment / deposition, the Fe-Ni alloy particles or the deposition surface is irradiated with nitrogen gas (or nitrogen ions), oxygen gas (or oxygen ions), etc., and the magnetic film provided on the non-magnetic support is Fe. -Ni-NO system film. During this film formation, the relationship between nitrogen gas (or nitrogen ions) and oxygen gas (or oxygen ions) is adjusted.

Since the Fe--Ni alloy material placed in the evaporation source does not have a purity of 100 wt%,
The metal magnetic film formed contains a metal element other than Fe and Ni. For example, Co, Mn, Cr, etc. are included.
Also, although it is a trace amount, Au, Pt, Ag, etc. are 0.05 w
It may be contained at t% or less. But anyway,
Since the content of metal elements other than Fe and Ni is about 5 wt% or less, the variation due to these metal elements is slight,
Specified by Fe, Ni, N, O.

By the way, F by the ion assisted vapor deposition method
When forming the e-Ni-N-O magnetic film, the Fe-Ni alloy may not be used if the binary vapor deposition method is used.
However, the Fe—Ni—N—O type magnetic film thus obtained did not provide a high reproduction output in the high range as in the present invention. The reason for this was considered as follows. Fe-
Since the Ni alloy is obtained by melting Fe and Ni, it is considered that Fe and Ni are also microscopically mixed with each other. When the material placed in the evaporation source is a Fe-Ni alloy, the evaporated particles in the future are also Fe-Ni particles, and even if the deposited film is observed microscopically, Fe-Ni particles are deposited. is there. That is, the deposited Fe-Ni- from the Fe-Ni alloy placed in the evaporation source.
Microscopic observation of the N-O magnetic film on the order of μm and c
Fe- in any macroscopic observation in the m-order
The deposited Fe—Ni particles in the Ni—N—O system magnetic film are
It consists of Fe-Ni alloy particles.

On the other hand, one evaporation source is Fe,
When Ni is placed as another evaporation source and a binary vapor deposition method is used, a Fe—Ni—N—O system magnetic film is obtained, but when this is observed on the order of μm, Fe of the intended composition is obtained. -Different from that of Ni alloy particles. From this, the obtained Fe-Ni-N-O-based magnetic film differs in a microscopic state depending on whether or not the material placed in the evaporation source is an alloy. Fe-Ni
Comparing the X-ray diffraction pattern of the --N--O system magnetic film with the X-ray diffraction pattern of the Fe--Ni--N--O system magnetic film formed by binary vapor deposition from metallic Fe and metal Ni, the Fe--Ni alloy The Fe-Ni-N-O-based magnetic film has a small peak full width at half maximum and a large saturation magnetic flux density. Due to this, the magnetic film of the present invention is considered to have a high reproduction output even in a high range, and the nitriding Is efficiently performed, and the productivity and the corrosion resistance are high.

FIG. 1 shows an ion assisted vapor deposition apparatus (in particular, an ion assisted oblique vapor deposition apparatus) used in the present invention.
In FIG. 1, 1 support 2a is a supply side roll of the support 1 and 2a
b is a roll on the winding side of the support 1, 3 is a cooling can roll,
4 is a shielding plate, 5 is a crucible, 6 is Ni at 2 to 15 at.
%, The balance is unavoidable impurities and Fe-Ni alloy of Fe, 7
Is an electron gun, 8 is a vacuum container, 9 is an oxygen gas supply nozzle, 1
0 is an ion gun. Instead of irradiating the oxygen gas supply nozzle 9 with O-activated species such as oxygen gas, one ion gun 10 may be used to irradiate both nitrogen ions and oxygen ions, or two ion guns may be used to separately supply nitrogen ions. And oxygen ions may be irradiated. And
The Fe—Ni—N—O system magnetic film according to the present invention can be obtained by performing the same method as the ordinary ion-assisted oblique vapor deposition except that the material placed in the crucible 5 is a specific Fe—Ni alloy.

The magnetic recording medium according to the present invention thus obtained is shown in FIG. In FIG. 2, 1 is a support. The support 1 may be magnetic or non-magnetic, but is generally non-magnetic. For example, polyester such as polyethylene terephthalate, polyamide, polyimide, polysulfone, polycarbonate,
Polymer materials such as olefin resins such as polypropylene, cellulose resins and vinyl chloride resins, inorganic materials such as glass and ceramics, and metal materials such as aluminum alloys are used. An undercoat layer for improving the adhesion of the magnetic film is provided on the surface of the support 1 as needed. That is, to improve the adhesion of the magnetic film formed by ion-assisted oblique vapor deposition by appropriately roughening the surface roughness, and further to improve the runnability by making the surface roughness of the magnetic recording medium surface moderate. The undercoat layer is formed by providing a coating film containing particles such as SiO ₂ and having a thickness of 0.01 to 0.5 μm.

A coercive force Hc of 10 is formed on the undercoat layer by the ion assisted oblique vapor deposition apparatus shown in FIG.
00 Oe or more, particularly 1200 to 1600 Oe, saturation magnetic flux density Bs 4000 to 7000 G, Fe 40 to 80 a
t. %, Ni is 1 to 14 at. %, N is 5 to 40 at.
%, O is 5 to 30 at. %, Especially 40 at. % ≦ Fe ratio ≦ 80 at. %, 1 at. % ≦ Ni ratio ≦ 14a
t. %, 5 at. % ≦ N ratio ≦ 40 at. %, 5a
t. % ≦ O ratio ≦ 30 at. %, O ratio <N ratio Fe—Ni—N—O based metal thin film type magnetic film 2
1 is 1500-2500Å, especially 1800-2200Å
It is formed thick. The minimum incident angle in oblique deposition is 30 ° to 8
It is 0 °, preferably about 45 ° to 70 °.

Reference numeral 22 denotes an Fe-Ni-NO magnetic system film 21.
It is a protective film with a thickness of about 10 to 200Å provided on the top surface. The protective film 22 is composed of, for example, a carbon film such as diamond-like carbon or graphite, or a silicon-containing film such as silicon oxide or silicon carbide. Among these, diamond-like carbon is preferable. 23 is
This is a lubricant layer provided on the protective film 22. That is, about 2 to 50Å by applying a coating agent containing a hydrocarbon-based lubricant or a fluorine-based lubricant such as perfluoropolyether, particularly a fluorine-based lubricant, by a predetermined means,
A lubricant layer 23 having a thickness of preferably about 10 to 30Å is provided.

Reference numeral 24 is a back coat layer having a thickness of about 0.1 to 1 μm, which is provided on the other surface of the support 1 and contains carbon black or the like. The back coat layer 24 is
It may be formed by vapor-depositing a metal such as an Al-Cu alloy. The Fe—Ni—N—O magnetic film of the present invention may have a single layer or two or more layers. Fe-Ni-
When there are two or more N—O based magnetic films, the composition of the Fe—Ni—N—O based magnetic film on the upper layer side should satisfy the above requirements. Further, a magnetic film other than the Fe-Ni-N-O based magnetic film may be provided. Even in this case,
It suffices if the Fe—Ni—N—O magnetic film is provided on the uppermost layer.

The magnetic recording medium configured as described above was excellent in corrosion resistance and electromagnetic conversion characteristics.

[0021]

Example 1 A PET film 1 having a thickness of 6.3 μm was mounted on the ion-assisted oblique vapor deposition apparatus shown in FIG.
PET film 1 in a vacuum atmosphere of 0 ^-6 Torr
Is being driven. Crucible 5 made of magnesium oxide
Fe-Ni (Fe; 98 at.%, Ni; 2 at.
%) Alloy 6 is contained, and the 10 kw electron gun 7 is operated to evaporate Fe-Ni, so that the PET film 1 has Fe-
Ni alloy particles were deposited. At this time, nitrogen gas was supplied to the ion gun 10 at a rate of 5 sccm, and oxygen gas was supplied from the oxygen gas supply nozzle 9 at a rate of 6 sccm.

After the Fe-Ni-N-O-based metal magnetic film was formed, a diamond-like carbon film was provided on the Fe-Ni-N-O-based metal magnetic film to a thickness of 100 Å. Furthermore, on top of this, perfluoropolyether (FO
MBLIN ZDOL (made by Montecatini Co.) is diluted with a fluorine-based inert liquid (Fluorinert FC-77 Sumitomo 3M Co., Ltd.) so as to have a concentration of 0.05 wt%, and a metal is formed by a die coating method so that a dry film thickness becomes 20 liters. It was applied onto the magnetic film and dried at 105 ° C.

On the back surface of the PET film 1 opposite to the Fe-Ni-N-O type metal magnetic film, the average particle size is 40 nm.
Of carbon black having a mean particle size of 80 nm is mixed at a ratio of 2: 1 and dispersed in a binder resin of urethane resin and vinyl chloride resin to form a back coat paint by a dry coating method by a die coating method. It was applied to a thickness of 0.5 μm and dried.

Then, it was slit into a width of 8 mm to obtain a magnetic tape for 8 mm VTR of the type shown in FIG. 2 (thickness of magnetic film; 1860Å, coercive force Hc; 1170 Oe, saturation magnetic flux density Bs; 6000 G).

[0025]

Examples 2 to 4 In Example 1, the Fe-Ni alloy put in the crucible 5, the amount of nitrogen gas introduced into the ion gun 10,
And the amount of oxygen gas introduced into the oxygen gas supply nozzle 9
8 mmV was performed according to Example 1 except that
A magnetic tape for TR was produced. Table-1 Fe-Ni alloy (at.%) Nitrogen gas amount Oxygen gas amount FeNi (sccm) (sccm) Example 2 95 5 7 8 Example 3 90 10 14 15 Example 4 85 15 35 35 10

[0026]

[Comparative Examples 1 to 3] In Example 1, the Fe-Ni alloy contained in the crucible 5, the amount of nitrogen gas introduced into the ion gun 10,
And the amount of oxygen gas introduced into the oxygen gas supply nozzle 9
8 mmV was performed according to Example 1 except that
A magnetic tape for TR was produced. Table-2 Fe-Ni alloy (at%) Nitrogen gas amount Oxygen gas amount Fe Ni (sccm) (sccm) Comparative Example 1 100 (Fe only) 7 11 Comparative Example 2 50 50 35 7 Comparative Example 3 80 20 507

[0027]

Comparative Examples 4 and 5 According to Examples 1 and 4, except that metallic Fe and metallic Ni were used instead of using the Fe-Ni alloy and binary vapor deposition was used in Examples 1 and 4. Then, a magnetic tape for 8 mm VTR was produced. The metal F
The use ratio of e and metallic Ni was the same as the composition ratio of Fe and Ni in the alloy used in the corresponding examples.

[0028]

[Characteristics] Regarding the magnetic tapes obtained in the above examples, Fe-N
The film composition, the coercive force Hc, and the saturation magnetic flux density Bs of the i-N-O magnetic film were examined, and the results are shown in Table-3. Table-3 Film composition (at%) Hc Bs Fe Ni 2 N 2 O (Oe) (G) Example 1 80 2 10 8 1170 6000 Example 2 71 5 14 10 1280 5600 Example 3 587 20 15 13 1310 4900 Implementation Example 4 51 9 30 10 1420 4700 Comparative Example 1 80-5 15 650 7000 Comparative Example 2 30 30 30 10 10 1150 3800 Comparative Example 3 40 10 40 10 1350 2800 Comparative Example 4 80 2 10 8 1190 5400 Comparative Example 5 51 9 30 10 1340 4500 Further, the corrosion resistance ΔBs (60 ° C., 9
The sample was left for 1 week in an environment of 0% RH, and the reproduction output at 1 to 15 MHz was examined, and the results are shown in Table-4.

Table-4 Corrosion resistance ΔBs reproduction output (dB) (%) 1 MHz 5 MHz 10 MHz 15 MHz Example 1 3 +5 +6 +5 +4 Example 2 3 +4 +5 +5 +5 Example 3 2 +3 +4 +6 +6 Example 4 1 +3 +4 +5 +5 Comparative Example 1 17 +4 0 -2 -4 Comparative Example 2 3 +2 +1 -1 -2 Comparative Example 3 2 0 0 0 0 Comparative Example 4 5 +3 +4 +3 +2 Comparative Example 5 3 0 +1 +2 +2

[0030]

The output is high in a wide range from the low range to the high range and the corrosion resistance is excellent.

[Brief description of drawings]

FIG. 1 is a schematic view of an apparatus for manufacturing a magnetic recording medium of the present invention.

FIG. 2 is a schematic diagram of a magnetic recording medium of the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H01F 41/20 H01F 41/20 (72) Inventor Junko Ishikawa 2606 Akabane, Kai Town, Haga-gun, Tochigi Prefecture Kao Co., Ltd. Information Science Research Institute (72) Inventor Katsumi Endo 2606 Akabane, Kaigacho, Haga-gun, Tochigi Prefecture Kao Co., Ltd. Information Science Research Institute

Claims (4)

[Claims] 1. Ni of 1 to 17 at. %, The balance is unavoidable impurities and Fe-Ni based alloys of Fe are used.
A magnetic recording medium comprising a Ni—N—O based magnetic film provided on a support, wherein the ratio of Fe in the magnetic film is 40-80 at. %, The ratio of Ni in the magnetic film is 1 to 14 at. %, The ratio of N in the magnetic film is 5 to 40 at. %, The proportion of O in the magnetic film is 5 to 30 at. % Is a magnetic recording medium. 2. The magnetic recording medium according to claim 1, wherein the ratio of N in the magnetic film is higher than the ratio of O. 3. Fe of 40 to 80 at. %, Ni is 1 to
14 at. %, N is 5 to 40 at. %, O is 5 to 30a
t. % Fe—Ni—N—O type magnetic film is provided, and a magnetic recording medium is provided on an evaporation source to form the Fe—Ni—N—O type magnetic film. As a material to be burned, Ni is 1 to 17 at. %, The balance being unavoidable impurities and Fe—Ni-based alloys of Fe, and Fe—Ni—N by the ion assisted deposition method.
A method of manufacturing a magnetic recording medium, which comprises forming an -O-based magnetic film. 4. The method of manufacturing a magnetic recording medium according to claim 3, wherein the ratio of N in the magnetic film is higher than that of O.