JPH0358302A - Method of magnetic recording/reproducing and magnetic recording medium - Google Patents

Abstract

PURPOSE:To reduce friction between a magnetic recording medium and a magnetic head and to prevent sticking or damage by specifying materials to constitute the medium such that a protective lubricating film provided on a magnetic layer contains an alcohol having >=30 deg.C m.p., fatty acid and ester. CONSTITUTION:The magnetic recording medium 1 consists of a rigid substrate 2 as a supporting body, magnetic layer 4 of a continuous thin film type formed on the substrate, and a protective lubricating film 6 on the magnetic layer 4. The substrate 2 is preferably made of glass having partly or wholly reinforced surface, on which the magnetic layer 4 of a continuous thin film type essentially comprising iron oxide is provided. The protective lubricating film 6 formed on the magnetic layer 4 contains each one or more kinds of alcohol having >=30 deg.C m.p., fatty acid and ester. By adding the fatty acid, the coefft. of friction and changes in friction after duration of traveling becomes extremely small. The magnetic layer 4 is a perpendicular magnetization film. Recording and reproducing is performed in the magnetic recording medium 1 with a floating type magnetic head.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a six-layer recording medium having a protective lubricant film having lubricating and protective functions, and a magnetic recording and reproducing method using the same.

<Prior Art> A hard type magnetic disk in which a magnetic layer is formed on a rigid substrate and a floating magnetic head are used in magnetic disk drives used in computers and the like.

Conventionally, coated magnetic disks have been used in such magnetic disk drive devices, but as the capacity of magnetic disks has increased, sputtering methods have been used because they are advantageous in terms of magnetic properties, recording density, etc. Thin-film magnetic disks having a continuous thin-film magnetic layer formed by a vapor phase deposition method or the like have come to be used.

Thin-film magnetic disks are made by plating an Ni-P underlayer on an Afi-based disk-shaped metal plate, or by oxidizing the surface of this metal plate to form alumite. Generally, a Cr layer, a metal magnetic layer such as Co--Ni, and a protective lubricant film such as C are sequentially deposited by a sputtering method.

However, a metal magnetic layer such as Co--Ni has low corrosion resistance and low hardness, causing problems in reliability. On the other hand, magnetic thin films mainly composed of iron oxide, such as those described in JP-A No. 62-438-19, are chemically stable, so there is no fear of corrosion, and they also have sufficient hardness. are doing.

On the other hand, a floating magnetic head is a magnetic head having a slider that generates buoyancy, and is usually a composite type in which the core is integrated with the slider, or a monolithic type in which the core also serves as a slider.

Furthermore, in addition to these, so-called thin-film floating magnetic heads are attracting attention because they are capable of high-density recording. A thin-film floating type magnetic head has a magnetic pole layer, a gap layer, a coil layer, etc. formed on a ceramic substrate by a vapor phase deposition method or the like. In such a thin-film floating magnetic head, the base body functions as a slider.

In these floating magnetic heads, the slider is made of various types of ferrite, AA20--TiC, Z
rO2, SiC. It is composed of various ceramics such as Aj2N.

In a magnetic disk device using a floating magnetic head, the floating surface of the floating magnetic head (surface on the magnetic disk side of the slider) of the floating magnetic head comes into contact with the magnetic disk during contact start/stop (CSS). At this time, the magnetic disk and the floating magnetic head are likely to be scratched or damaged, or the floating magnetic head is likely to be attracted to the magnetic disk. For this reason, proposals have been made to provide various protective films or lubricant films on the surfaces of magnetic disks or magnetic heads.

In particular, since iron oxide has higher hardness than metals such as Co-Ni, in a magnetic disk having an iron oxide magnetic layer as described in JP-A-62-438-19, even if the surface of the magnetic disk is Even if lubrication or a protective film is provided, the head floating surface is likely to be damaged by repeated CSS, and the friction between the head and disk is likely to increase.

Therefore, in such a combination, care must be taken in selecting the materials constituting the lubricating film or the protective film.

In addition, magnetic disks with iron oxide magnetic layers and Mn-Zn
When used in combination with a floating head having a ferrite base, such problems become even more pronounced because the hardness of Mn-Zn ferrite is lower than that of iron oxide.

Furthermore, for thin-film magnetic disks with iron oxide magnetic layers, Al203-, which has higher hardness than Mn-Zn ferrite,
Tic. ZrO2, SiC. When using a floating magnetic head having a substrate such as Aj2N, the above problems are solved to some extent, but in such a combination of a magnetic disk and a floating magnetic head, both the magnetic layer and the slider have high hardness. Therefore, higher lubrication and protection effects are required. In particular, when a thin-film flying type magnetic head is used for high-density recording, the above problems become more serious.

In other words, in a magnetic disk drive device that uses a thin-film floating magnetic head, the distance between the magnetic disk and the magnetic head (flying height) can be set extremely small in order to perform high-density recording. This is because if a contact accident occurs between the magnetic disk and the floating magnetic head due to an external shock or the like, or if the flying bite is small, the damage to the magnetic head and magnetic disk during CSS will be greater.

In particular, a magnetic disk having a magnetic thin film mainly composed of iron oxide, as described in JP-A No. 62-43819, uses a glass substrate with a mirrored surface, and the surface of the magnetic layer is Chew is very small.

Therefore, unless a suitable protective film is selected, the friction between the magnetic disk and the magnetic head will increase, causing problems such as stick-slip or adsorption of the magnetic head during CSS or the like. Therefore, even in such a combination, care must be taken in selecting the materials constituting the lubricating film or the protective film.

Various lubricants are used in protective lubricant films provided on the above-mentioned flying magnetic heads and magnetic recording media.

On the other hand, the recording density of magnetic recording media continues to increase, but in the conventionally widely used in-plane recording method of the magnetic layer, M magnetism is generated due to the action of the demagnetizing field in the magnetic layer, making it difficult to increase the recording density beyond a certain level. Have difficulty.

Perpendicular magnetic recording media have been proposed for such longitudinal recording.

Perpendicular magnetic recording is a method of recording by magnetizing a magnetic layer in the perpendicular direction. In perpendicular magnetic recording, demagnetization decreases as recording density increases, so extremely high density recording can be performed without being affected by demagnetization.

Perpendicular magnetic recording media include soft magnetic films such as permalloy and Co-
A device in which spattered magnetic layers of Cr alloy are sequentially formed is well known.

Further, a thin film type magnetic head is suitable as a magnetic head for performing high density recording on such a perpendicular magnetic recording medium. A thin film type magnetic head has a magnetic pole, a protective film, and the like laminated on a ceramic substrate by a thin film forming method such as a sputtering method.

As described above, perpendicular magnetic recording media are suitable for high-density recording in principle, but when considering practical use, the following performance is required.

■High durability.

■High corrosion resistance and weather resistance.

■Good head touch under high-speed recording/reading.

■High playback output.

■Low occurrence of modulation.

■High productivity.

etc.

In order to satisfy such performance, the present inventors developed a substrate,
In a perpendicular magnetic recording medium that has a soft magnetic film, a magnetic layer, a protective layer, and a lubricating layer in this order, we have proposed limiting the physical properties and constituent materials of each component (Japanese Patent Laid-Open No. 63-1
97028).

In addition, the present inventors further developed this proposal and R(
However, R represents one or more elements selected from rare earth elements including Y. Perpendicular magnetic recording comprising a solid protective layer containing l or more elements selected from metals or semimetals excluding ), O and N, and further containing 1 to loat% of R with respect to these elements We are proposing media (
(Japanese Patent Application No. 1996-96964), and has also proposed regulating the contact angle of the surface of the solid protective layer with water (Japanese Patent Application No. 1-96964).
-98077).

The magnetic recording media proposed in these proposals satisfy the above-mentioned performance items 1 to 2 at a high level, and are particularly durable, corrosion resistant, and
Weather resistance is extremely high. Furthermore, uneven wear of the magnetic head is also prevented.

However, since perpendicular magnetic recording media perform extremely high-density recording, even higher reliability is required.

In each of the above proposals, since the magnetic head is constantly sliding against the magnetic recording medium, the selection of the lubricant film provided on the solid protective layer is important in order to ensure reliability.

That is, in addition to being naturally required to have a low coefficient of friction, it is also required that the friction reduction effect does not decrease even after repeated use.

Problems to be Solved by the Invention> However, in the media and heads of these various systems, a sufficient protective lubricating effect cannot be obtained with the conventional protective lubricating film.

Further, with conventional protective lubricant films, it is difficult to form a thin and uniform film on a magnetic recording medium or a magnetic head. For this reason, the friction between the magnetic recording medium and the magnetic head changes significantly between the initial stage and after running, resulting in stick-slip and further deterioration of the protective lubrication effect.

The object of the present invention is to reduce the friction between the magnetic recording medium and the magnetic head and to reduce its fluctuation during endurance running, that is, to prevent stick-slip from occurring, and to reduce the friction between the magnetic head and the magnetic recording medium. It is an object of the present invention to provide a magnetic recording medium that is less likely to be attracted and moreover less likely to cause scratches or damage to the magnetic head and the magnetic recording medium, and to provide a magnetic recording and reproducing method using the same.

Means for Solving the Problems> Such objects are achieved by the following inventions (1) to (6).

(1) A method for recording and reproducing information on a magnetic recording medium having a continuous thin magnetic layer using a magnetic head having a ceramic substrate, the melting point A magnetic recording and reproducing method comprising a protective lubricating film containing alcohol at 30° C. or higher and further containing a fatty acid and an ester.

(2) The magnetic recording according to (1) above, wherein the magnetic layer has iron oxide as a main component, the magnetic recording medium has this magnetic layer on a rigid substrate, and the magnetic head is of a floating type. How to play.

(3) The magnetic recording and reproducing method according to (1) above, wherein the magnetic layer is a perpendicularly magnetized film, and a solid protective layer is provided in contact with the perpendicularly magnetized film.

(4) The ceramic substrate has a Vickers hardness of 10
00 or more, and the magnetic head has a thin film magnetic pole layer on the ceramic substrate.

(5) Continuous thin 'Aa Fa mainly composed of γ-FeJ3
In the X-ray diffraction chart of this magnetic layer, γ-Fe*O
Surface index of s (400). The peak area of each of the plane index (2 2 2) and plane index (311) is P (400)
．． When P(222) and P(311), O≦P(400)/P(311)≦1.00≦P(22
2)/P(311)≦0. 5, the surface roughness (Rmax) of the rigid substrate is 10 to 100, and the surface roughness (Rmax) of the surface on the magnetic layer side is 50 to 100.
200 C. A magnetic recording medium having a protective lubricating film on the magnetic layer containing an alcohol having a melting point of 30° C. or higher and further containing a fatty acid.

(6) A magnetic recording medium in which a soft magnetic film, a perpendicular magnetization film, a solid protective layer, and a protective lubricant film are provided in this order on a support, the solid protective layer being R (where R is Y O and N, and one or more elements selected from rare earth elements including O and N. ~1
A magnetic recording medium containing 0 at% R, wherein the protective lubricant film contains an alcohol having a melting point of 30° C. or higher, and further contains a fatty acid and an ester.

Effect> In the present invention, on the continuous thin film layer of the magnetic recording medium and/or on the ceramic substrate of the magnetic head,
In addition to alcohol at temperatures above ℃, it has a protective lubricating film containing fatty acids and alcohol.

The action of this protective lubricant film reduces the coefficient of friction between the magnetic recording medium and the magnetic head, reduces the tendency of friction fluctuations,
To prevent stick-slip and film scratching during durability running, to prevent damage to the medium and head when the magnetic head contacts the medium, and to prevent the head from adhering to the surface of the medium.

Of these, in particular, the effect of reducing initial friction and the effect of reducing friction fluctuation after endurance running are the effects of a compound of the above three in a system using a medium having a continuous thin film magnetic layer and a thin film head having a ceramic substrate. This effect is selectively and significantly expressed when used in combination.

Specific composition> Hereinafter, a specific configuration of the present invention will be explained in detail.

A magnetic recording medium 1 according to a first embodiment of the present invention shown in FIG. It has a membrane 6.

The substrate used in the present invention simplifies the manufacturing process as there is no need to provide an underlayer, etc., and it is easy to polish and control the surface roughness. Because it can withstand heat treatment for roughness control, etc.
Preferably, glass is used.

As the glass, it is preferable to use tempered glass, particularly surface-strengthened glass obtained by chemical strengthening.

In general, surface-strengthened glass replaces alkali ions near the glass surface with other types of alkali ions supplied from the outside at a temperature below the glass transition temperature, and the difference in occupied volume of these ions causes the glass surface to grow. This takes advantage of the fact that compressive stress is generated.

Ion replacement is carried out by immersing the glass in a molten salt of alkali ions.

As the salt, nitrate, sulfate, etc. are used, the temperature of the molten salt is about 350 to 650°C, and the immersion time is about 1 to 24 hours.

More specifically, examples include a method in which KNO3 is used as the alkali molten salt to exchange K ions with Na ions in the glass, and a method in which Na ions in the glass are exchanged with NaN03. Further, Na ions and Li ions in the glass may be exchanged at the same time.

Since the reinforced layer obtained in this way, that is, the compressive stress layer, exists only near the surface of the glass substrate, it becomes surface-strengthened glass. The thickness of the compressive stress layer is 10 to 200 μm
In particular, it is preferably 50 to 150 μm.

Note that such surface reinforcement may be applied to the entire surface of the glass substrate, or may be applied to a part of the surface.

The glass substrate preferably has a contact angle with water of at least the surface on the magnetic layer side of 20'' or less, particularly preferably 10'' or less.

By setting the contact angle with water within such a range, the adhesion of a continuous thin film type magnetic layer containing iron oxide as a main component as described later is improved. Note that there is no particular restriction on the lower limit of the contact angle, but it is usually about 2° or more.

The contact angle with water may be measured, for example, after dropping pure water on the surface of the glass substrate and 30 seconds later.

The measurement atmosphere is approximately 18 to 23°C and 40 to 60% RH.

In order to obtain such a contact angle, the glass substrate is preferably subjected to the following treatment.

First, the surface of the glass substrate is polished, then subjected to the above-described strengthening treatment, and then the surface of the glass substrate is polished again.

It is preferable to achieve the surface roughness described later by this polishing.

After cleaning the polished glass substrate with pure water, it is preferable to perform further cleaning through the steps of detergent cleaning, pure water cleaning, and organic solvent vapor drying.

Note that this step may be combined with brush scrub cleaning as appropriate.

The surface roughness (Rmax) of the rigid substrate is preferably 10 to
The capacity is 100 people, more preferably 40 to 80 people, and even more preferably 40 to 60 people. By setting the R max of the rigid substrate within this range, the durability of the magnetic recording medium is improved, and the R m of the surface on the magnetic layer side of the medium as described later is improved.
ax can be easily obtained.

Note that R max may be measured according to JIS B 0601.

Such surface roughness is described, for example, in Japanese Patent Application Laid-Open No. 62-4381.
It can be obtained by mechanochemical boiling as described in Japanese Patent No. 9 and Japanese Patent No. 63-175219.

The material of the glass substrate is not particularly limited and can be appropriately selected from borosilicate glass, aluminosilicate glass, quartz glass, titanium silicate glass, etc. However, aluminosilicate glass is particularly preferred because of its high mechanical strength. It is preferable to use

Note that when the surface of the glass substrate is smoothed by mechanochemical boring, it is preferable to use glass that does not contain crystalline substances. This is because the grain boundaries are polished relatively quickly by mechanochemical boring, making it impossible to achieve the above R max.

Although there are no particular restrictions on the shape and dimensions of the glass substrate, it is usually disk-shaped, with a thickness of about 0.5 to 5 mm and a diameter of about 25 to 300 mm.

On the rigid substrate 2, a continuous thin film type magnetic layer 4 containing γ-Fe20s as a main component is formed.

When this magnetic layer was subjected to X-ray diffraction, the surface index of γ-Fear3 was (400) in the X-ray diffraction chart. The respective peak areas of plane index (222) and plane index (311) are calculated as P(400), P(222) and P(31).
1), 0≦P(400)/P(311)≦
1.00≦P(222)/P(311)≦0. 5
and more preferably O≦P(400)/PC311)≦0.60≦P(22
2)/P(311)≦0. It is preferable that it is 3.

At the same time, the surface roughness (R
max) is 50 to 200 people, preferably 80-1
50 people, more preferably 80 to 120 people, even more preferably 90 to 120 people.

By having such a peak area ratio and R max, durability is improved, and in particular, CSS durability is improved.

To explain in more detail, an increase in P(222) means that the (222) plane and (1 1
1) It shows that the proportion of faces that exist increases.
γ-Fezes has a Subinel structure, and in the spinel structure, the (111) plane is the most slippery plane.

Therefore, if the peak area of the (222) plane parallel to the (1 1 1) plane is large, that is, P(222)/P(31
If the value of 1) is large, it is considered that the γ-Fe 20a constituting the magnetic layer tends to slip due to sliding with the magnetic head, resulting in decreased durability.

When P(222)/P(3111) exceeds the above range, durability is critically reduced.

The (100) plane that exists parallel to the (400) plane is (1 1
1) P is considered to be the second most prone to slipping after surface
When (400)/P(311) exceeds the above range, durability is critically reduced.

Furthermore, if R max of the surface of the 6a magnetic layer is within the above range, the durability is improved, and the distance between the surface of the magnetic layer and the floating surface of the floating magnetic head is maintained at 0.1 μm or less for recording and reproduction. Furthermore, there is no adhesion between the floating magnetic head and the magnetic recording medium, and high-density recording is possible.

Further, in the present invention, it is preferable that the magnetic layer contains α-Fears. Containing α-FeaO3 in the magnetic layer improves durability.

When the magnetic layer containing α-Fear was subjected to X-ray diffraction, in the X-ray diffraction chart, a-Fe
The peak area of the plane index (104) of 2r3 is P(104)
When, preferably 0.02≦P(104)/P
(311)≦0.20, more preferably 0.05≦P(104)/P(311)≦0, l5.

If the magnetic layer has such a peak area ratio, the durability will be further improved.

To explain in more detail, P(104)/P(311)
is less than the above range, the durability improvement effect is relatively low;
When the above range is exceeded, the recording and reproducing output decreases.

The X-ray diffraction chart is preferably created, for example, as follows.

FIG. 2 shows an example of an X-ray diffraction apparatus.

In FIG. 2, X-rays irradiated from an X jI source 101 enter the magnetic layer of the magnetic recording medium 102 through a divergence slit DS, are diffracted, and after passing through a scatter slit SS and a receiving slit RS. The X-rays are reflected by the monochrome make MM to become monochromatic light, and then enter the counter tube 103 through the receiving slit RS, where the X-ray intensity is counted and usually recorded by a rate meter or the like.

Note that during measurement, the magnetic recording medium 102 has a scanning speed dθ
/dt, the members constituting the optical path below the scatter slit SS are rotated at a scanning speed of 2dθ/dt.

For each peak in the obtained X-ray diffraction chart, a portion excluding the background is integrated to calculate the above-mentioned area ratio.

In addition, in the optical arrangement shown in FIG. 2 using CuKα as the X-ray source, the peak of the plane index (104) of α~Fear3 is 33
．． It appears near 3@, and the plane index of y-Fe203 (400
). The peaks of plane index (222) and plane index (311) are 43.5° 37.3” and 35.6, respectively.
``Appears nearby.

In addition, when α-Fears are contained in the magnetic layer, α
-Fears may be contained uniformly, but it is preferable that the content is higher on the surface side of the magnetic layer, that is, on the side opposite to the substrate.

By containing α-FeJs in this way, it is possible to further strengthen the surface part of the magnetic layer that is easily damaged by the sliding of the magnetic head, and moreover, it is possible to further strengthen the surface part of the magnetic layer, which is easily damaged by the sliding of the magnetic head. α-Fe2e! content can be kept low.

In this case, α-Fezes may gradually increase toward the surface side of the magnetic layer, or may not exist on the substrate side but only on the surface side.

The content of α-Fe20a near the surface of the magnetic layer is preferably analyzed, for example, as follows.

FIG. 3 shows an example of a low incidence angle X-ray diffraction device.

In Figure 3, the X-rays irradiated from the X-ray source Lot are
The light passes through the solar slit S1, enters the magnetic layer of the magnetic recording medium 102 at an angle β with the surface thereof, and is diffracted.

After passing through the solar slit S2, the diffracted X-rays are reflected by a monochromator MM to become monochromatic light,
Furthermore, the X-rays enter the counter tube 103 through the receiving slit RS, and the X-ray intensity is counted.

In this low-incidence-angle X-ray diffraction device, unlike the device shown in FIG. 3, the magnetic recording medium 102 is fixed with respect to the incident X-rays during measurement, and the members constituting the optical path below the Solar slit 82 control the scanning speed. It is rotated by 2dθ/dt.

In this device, by changing the angle β between the incident X-ray and the magnetic layer surface, α-
The distribution of Fe20s can be determined. Specifically, in order to analyze a portion close to the surface, it is sufficient to reduce β, and as β becomes larger, analysis results deeper into the magnetic layer can be obtained.

In the present invention, in such a low incident angle / P(311), β=2.0
Measured as m, data P(104)/P(311)+
7) It is preferably 1.5 to 10 times, particularly 1.5 to 5 times.

A continuous thin film type magnetic layer containing γ-FeJa as a main component is made by first forming FesO+, and then oxidizing this FIB304 to form γ.
It is preferable to form one Feign.

The method for forming FesOn may be a direct method or an indirect method, but it is preferable to use a direct method because the above-mentioned peak area ratio can be easily obtained and the process is simple. .

The direct method uses the reactive sputtering method to deposit Fes0 on the substrate.
This is a method of directly forming 4. The direct method includes an oxidation method using Fe as a target in an oxidizing atmosphere, and an oxidation method using α-Fe as a target. Examples include a reduction method using Os in a reducing atmosphere and a neutral method using FesO as a target. However, in the present invention, the oxidation method is used because it is easy to control spatter and has a high film formation rate. It is preferable to use

In the oxidation method, 02 gas is added as a reactive gas to an Ar gas atmosphere to perform sputtering.

In order to obtain the above-mentioned peak ratio of γ-Fe2ts in X-ray diffraction, it is necessary to obtain the peak ratio of 02 gas. It is preferable that the pressure PO■ and the total pressure P fAr+oi of Ar gas and 02 gas are as follows, and in particular, ? It is preferable that there be.

Further, during sputtering, it is preferable that the 02 gas be introduced into the vacuum chamber by spraying it onto the substrate.

The preferred range of P(^rho■) in the present invention is I
X 1 0-4 to I X 1 0-”Torr,
Especially 5 X 1 0-' to 8 X 1 0-3To
It is rr.

Note that it is preferable to use RF sputtering as the sputtering method.

There is no particular limit to the power input to the spatter, but it is 0.2 to 2 kW.
It is particularly preferable to set it as 0.4-1.5kW.

For details on Fez04 thin film formation by direct method, please refer to the following. IEICE Journal '80/9 Vol. J63-C No. 9
p. 609-616, and in the present invention, it is preferable to form the magnetic layer according to this, and at that time, it is preferable to perform sputtering at the above-mentioned 02 partial pressure.

Note that the indirect method uses Fe as a target to form α-FezOs in an oxidizing atmosphere, and then reduces it to FeO
This is the way to get 4.

FesO< formed by sputtering is γ-Fez
It is oxidized to 03.

This oxidation occurs at a gas partial pressure of 0.05~0. The heat treatment may be carried out in an atmosphere of about 8 atmospheres or a total pressure of about 0.5 to 2 atmospheres, and it is usually preferable to carry out the heat treatment in the atmosphere.

The holding temperature during heat treatment is 200-400℃, especially 25
The temperature is preferably 0 to 350°C, and the temperature holding time is
Preferably, the time is 10 minutes to 10 hours, particularly 1 hour to 5 hours.

In order to easily obtain the above-mentioned peak area ratio of α-FeJs, the heating rate must be set at 3.5 to 2.
0℃/min, especially 5.0-12℃/min
It is preferable to set it to n.

Note that the temperature increase rate may be constant, gradually increased or decreased, or a plurality of temperature increase rates may be combined to increase the temperature to the retention level.

In addition, when performing this heat treatment, by controlling the heat treatment temperature and time, R max on the magnetic layer side of the magnetic recording medium can be
can be within the above range.

The magnetic layer formed in this way has a coercive force of 400 to 2
000 0e. Magnetic properties with a residual magnetization of 2000 to 3000 G and a squareness ratio of about 0.55 to 0.85 are obtained. Furthermore, there is almost no deterioration in magnetic properties due to the inclusion of Q-Fe203.

In the magnetic layer, Co. Ti. Cu or the like may be added, or Ar or the like contained in the film forming atmosphere may be contained.

Does the thickness of the magnetic layer take productivity, magnetic properties, etc. into account? 50
It is preferable to set the number to about 0 to 3000 people.

A protective lubricant film 6 is provided on the magnetic layer 4 as described above.

This protective lubricating film contains alcohol with a melting point of 30°C or higher,
One or more of fatty acids and esters are used.
Examples of such alcohols include the following.

A. Alcohol monohydric saturated alcohol having a melting point of 30°C or higher, CH. (CHI), ■OH CHs (CHz)+sOH CHs (CH2) 150H CH. (CH.). ? OH CH3 (cHt) 190H CHs (CHg) 210H CH3 (CHa)'*sOH CH. (CHI)zsOH CH. (CHI). , OH C H s ( C H 2) + − C H O
H C H aCH. (CH2) . 8CH
OHCH. CH3 (CH.) . ,CHOHCH
．． etc.

l-hydric to polyhydric natural alcohol, synthetic alcohol, etc.

Among these, monovalent saturated alcohols are preferred, and linear or branched monovalent saturated alcohols are more preferred.

One type or two or more types of the above alcohols are used for the protective lubricant film. Therefore, a uniform thin film can be formed.

Such a protective lubricating film further contains one or more fatty acids.

By adding fatty acids, the coefficient of friction and the fluctuation in friction after endurance running become extremely small.

Examples of fatty acids include the following:

Bl. Monounsaturated fatty acids with a melting point of less than 30°C; Naso monoenoic acids such as 9-undecylenic acid, 10-undecylenic acid, oleic acid, etc.

As di-, tri-, etraenoic acid, linoleic acid Linolenic acid etc.

B2. Monovalent saturated fatty acid with melting point less than 30'C; CH
a (CHa)ecOOH etc.

B3. Examples of monounsaturated fatty acid direct monoenoic acids with a melting point of 30°C or higher include 2-balmitoleic acid and elaidic acid.

As di-, tri-, and tetraenoic acid, sorbic acid alpha-eleostearic acid β-eleostearic acid α-valinaric acid β-parinaric acid etc.

? 4. Monovalent saturated fatty acid with a melting point of 30°C or higher; CH3C
H2 acOOH CH. CHI. oCOOH CH3 CH2 +2COOH CH3 CH* 14cOOH CHs CHa ,acOOH CH3 C82■COOH CH. CH2')2. COO}l CHa CHz■. COOH CI{a(CHa a4COOt{ CH. CH2 2ecOOll CHs CH2 211COOll C}Is CHi s. COOH CH. CH. ... COOH CHa CHx 34COOH B5. Natural fatty acid (1.2-hydroxystearin acid,
lanolin fatty acids, etc.); B6. Various synthetic fatty acids; B7. Fatty acid derivatives, etc.

Among these, preferable are linear monovalent saturated or unsaturated fatty acids having a melting point of 30'C or more and a total carbon number of 10 to 36.

The protective lubricating film further contains one or more esters.

By adding ester, the coefficient of friction and the fluctuation in friction after endurance running become extremely small.

Esters that can be suitably used include the following.

C.I. Ester with melting point below 30°C; C. l{gacOOcHs C+sHatCOOCHs C+ +HazCOOC-Ha C1sH*γCOOCzHs C. ．． H. , COOC. }I. C+ JasCOOC4H@C. ,}12,C:00C. H. C. -Ha +COOC4Ha c, ,HsaCOOC. He C,. Il. , COOC. H. ．． C. , [{. ．． COOC. H. CHx (CH.), CH=CH(CH2), COO(
CHI)a-CI-1=cH(CH.). CH3 CL (Cll2)? CI{=CH (CHI)?
COO (CH2). CH3CHs (C}121?
cH(CH8)7COOCll2Cl{(CH!)-O
CO(CL), CH=CH(CL)7CLC2. Melting point 3
Ester of 0'C or more; CH3 (CHI) l
．． COOCH3CI{3(CH2} 1 6GOOCH
3CH3CH2)18cOOcH3 CH3CHa)2oCOOCH3 CHs CH2)24COOCHz CI13 CH2) + ecOOcJsC,}+3
(CH2)a4cOOc2HsCHz(CH2)+sf
:00CeH+t and others, preferably linear 1
Total saturated or unsaturated carbon number of 10 to 36, especially 12
It is a fatty acid ester of ~30 fatty acids and a linear, monovalent, saturated or unsaturated alcohol with a total carbon content of l~30.

Of these, in order to obtain a higher protective lubrication effect,
Esters with a melting point of 30°C or higher are preferred.

One or more of these alcohols with a melting point of 30°C or higher, fatty acids, and esters are
~80 mol%, fatty acids 5-75 mol%, esters 5
It is mixed so that it becomes 75 mol%.

In the present invention, the thickness of the protective lubricating film is preferably about 4 to 100 layers. If the number is less than 46, the sufficient effect of the present invention cannot be obtained and the durability is particularly poor, and if the number exceeds 100, attraction may occur and the magnetic head may crash. In addition, the more preferable monthly thickness is 4 to 80 people,
A more preferable film thickness is 5 to 40 people. In particular, those consisting of a monomolecular layer are preferred.

There are no particular restrictions on the method of forming the protective lubricant film, and Langmuir Projet (LB)/removal/application can be used. You can choose from among the above.

For example, when using the LB method, the adherend substrate (magnetic recording medium or floating magnetic head) is immersed in an aqueous phase. Next, a predetermined amount of a predetermined alcohol developing solution is uniformly dropped onto the aqueous phase to develop a monomolecular film.

Next, after compressing the gas-liquid interface until the surface pressure reaches a predetermined tension, the adherend substrate is lifted almost vertically out of the aqueous phase at a predetermined speed while compressing the interface to maintain a constant pressure. , transfer the monolayer onto the adherend substrate. Next, the attached water is dried if necessary. Furthermore, if necessary,
Obtain a cumulative film by repeating the same operation.

The cumulative number is preferably about 1 to 20 layers, more preferably about 1 to 5 layers, particularly preferably one layer, that is, a monomolecular layer.

Note that the surface of the adherend substrate may be treated to make it hydrophobic or hydrophilic, and an organic film may be formed thereon by the LB method.

Further, the hydrophilic treatment may be performed by a plasma method, a sputtering method, a solvent, ion bombardment, reverse sputtering, or the like.

The solvent used in the LB method includes hydrocarbons (xylene, benzene, etc.) and halogenated hydrocarbons (
Chlorinated solvents such as chloroform, fluorinated solvents such as CFCs, etc.), nitrated hydrocarbons (nitrobenzene, etc.),
Alcohols (ethyl alcohol, methyl alcohol, proyl alcohol, etc.), ketones (acetone, etc.)
, heterocyclic compound type (quinoline etc.), amine type, ether type, ester type, acid type, etc.

In addition to the LB method, the protective lubricant film of the present invention can also be formed by a coating method.

When a coating method is used, the developing solution used in the LB method described above can be used as the coating solution. Further, the coating method may be appropriately selected from spin coating, dipping, spray coating, etc.

The magnetic recording medium of the present invention is effective when recording and reproducing is performed using a known composite floating magnetic head, monolithic floating magnetic head, etc., but is particularly effective when used in combination with a floating thin film magnetic head. When used with
Shows extremely high effectiveness.

FIG. 4 shows an example of a thin-film floating type magnetic head which is a preferred embodiment of the magnetic head used in the present invention.

The floating magnetic head 10 shown in FIG.
and a protective layer 70 in this order. Furthermore, at least the front surface, ie, the floating surface, of such a floating magnetic head 10 may be provided with a lubricating film similar to that described above, if necessary.

In addition, in the present invention, R max of the front surface is 200
The number of participants is preferably 50 to 150, particularly 50 to 150.
A magnetic head having such R max and the above-mentioned R
The effects of the present invention are further improved by using it in combination with a magnetic recording medium having max.

There is no particular restriction on the material of the coil layer 60, and a commonly used metal such as A.degree. C. or Cu may be used.

There are no restrictions on the winding pattern or winding density of the coil, and known patterns may be appropriately selected and used. For example, as for the winding pattern, in addition to the spiral type shown in the figure, the laminated type,
It may be of any type, such as a zigzag shape.

Further, the coil layer 60 may be formed using various vapor deposition methods such as sputtering.

The base body 20 may be made of a known material such as Mn-Zn ferrite.

When such a magnetic head is used for the magnetic recording medium of the present invention, the base body 20 has a Vickers hardness of 100
0 kgf/mm2 or more, especially 1000~3
It is preferable that the structure is made of a ceramic material of about 0 0 0 kgf/mm''. By configuring it in this way, the effects of the present invention become even more remarkable.

Ceramic materials with a Vickers hardness of l○O kgf/mm2 or more include ceramics mainly composed of AI2z 03-TiC, ceramics mainly composed of ZrO2, ceramics mainly composed of SiC, or ceramics mainly composed of A42N. Ceramics as a component are suitable.

These also contain Mg, Y. ZrOa
, TiO2, etc. may be contained.

Among these, those particularly suitable for the present invention are Aβa O
3- Ceramics mainly composed of T i C, Si
Ceramics containing C as a main component or ceramics containing A42N as a main component are the most preferred among these because they have an optimal relationship with the hardness of the thin film magnetic layer containing iron oxide as a main component. It is a ceramic mainly composed of Os-Tic.

As the material for the lower and upper magnetic pole layers 41 and 45, any conventionally known material can be used, such as vermalloy, sendust, Co-based amorphous alloy, etc.

The magnetic poles are usually provided as a lower magnetic pole layer 41 and an upper magnetic pole layer 45 as shown, and a gap layer 50 is formed between the lower magnetic pole 1141 and the upper magnetic pole 1i145.

? The cap layer 50 is made of AAz 03 . It may be a known material such as Si02.

The patterns, film thicknesses, etc. of these magnetic pole layers 4l, 45 and gap layer 50 may be any known ones.

Furthermore, in the illustrated example, the coil layer 60 is of a so-called spiral type, and the upper and lower magnetic pole layers 41 are arranged in a spiral shape.
, 45, and insulating layers 33, 35 are provided between the coil layer 60 and the upper and lower magnetic pole layers 4l, 45.

Further, an insulating layer 31 is provided between the lower magnetic pole layer 41 and the base body 20.

As the material for the insulating layer, any conventionally known material can be used. For example, when a thin film is formed by a sputtering method, SiO2, glass, AI2-Os, etc. can be used.

Further, a protective layer 7o is provided on the upper magnetic pole 45. Any conventionally known material can be used as the material for the protective layer, and for example, AAtOs or the like can be used. Further, various resin coat layers or the like may be laminated thereon.

The manufacturing process for such a thin film floating type magnetic head usually consists of forming a thin film and forming a pattern.

As mentioned above, to create the thin films constituting each of the above layers,
A conventionally known vapor phase deposition method such as a vacuum evaporation method, a spatter method, or a plating method may be used.

Pattern formation of each layer of the floating magnetic head can be performed by conventionally known selective etching or selective deposition. Wet etching or dry etching can be used as the etching.

Such a floating magnetic head is used in combination with a conventionally known assembly such as an arm.

The magnetic recording medium of the present invention using such a magnetic head,
In particular, when recording and reproducing information on a magnetic disk, the magnetic head is made to float while the magnetic disk is being rotated.

The disk rotation speed is approximately 2,000 to 6,000 rpm, particularly 2,000 to 4,000 rpm.

Also, the floating height is 0. 2,in or less, especially 0.15μs or less, even 0.1 μs or less, for example 0.01 to 0.0
9 pm, and in this case, good flying characteristics and CSS durability can be obtained.

The flying height is adjusted by changing the slider width and the load on the magnetic head.

Further, if a protective lubricant film as described above is formed on the front surface of the magnetic head, the CSS durability is further improved.

Also, when a magnetic head having a protective lubricant film as described above is used for a magnetic recording medium having a magnetic layer like the above-described magnetic recording medium of the present invention, a good C.sub.
SS durability can be obtained.

FIG. 10 shows a preferred embodiment of the magnetic recording medium according to the second aspect of the present invention.

The magnetic recording medium 1 of the present invention has a soft magnetic film 3, a continuous thin film perpendicularly magnetized magnetic layer 4, a solid protective layer 5, and a protective lubricant IlI 6 in this order on a substrate 2 as a support.

Note that when the support 2 is made of a flexible material, the soft magnetic film is 3. The magnetic layer 4, solid protective layer 5 and lubricating film 6 are preferably provided on both sides of the substrate 2, as shown in FIG.

However, they can also be provided on one side of the substrate 2.

When a flexible support is used for the substrate 2, warpage of the substrate 2 can be prevented by providing a back coat layer on the other side. In this case, the back coat layer may be made of metal such as 84, Ti, or Sins. Sis Na. A (2203) A spatter film made of an inorganic oxide, nitride, or a mixture thereof, such as a solid protective layer structure or material described later, is suitable, and a coated back coat layer can also be used.

The substrate 2 may be flexible or rigid, and may be disk-shaped or tape-shaped, and may be selected depending on the intended use of the magnetic recording medium 1.

When the substrate 2 is made flexible, there are no particular restrictions on its structure or material, but polyimide, polyethylene terephthalate (
PET). Polyphenylene sulfide (PPS). It is preferable to select polymer materials such as polyamide, polyethylene naphthalate (PEN), and polyether ether ketone (PEEK), since they have good heat resistance, dimensional stability, surface roughness, etc. It is more preferable to use polyimide.

In addition, when the substrate 2 is made rigid, there is no particular restriction on its constituent material, but various types of glass, various ceramics, various metals,
For example, it is preferable to select from Aj2, 8β-based alloys, various resins such as polyimide, polycarbonate, etc. Among these, glass is preferred because it has good moldability in terms of heat shrinkage rate, surface roughness, etc. It is more preferable.

In addition, since it is preferable that the magnetic layer composed of a Co-Cr alloy is subjected to heat treatment in order to improve its magnetic properties, the material of the base 2 in this case should be one that can withstand heating of about 120°C or more. It is preferable to select

If the substrate 2 is flexible, its Young's modulus is 300
It is preferably 1,000 kgf/mm''.

By setting the Young's modulus within this range, durability is improved and head touch is improved. When the Young's modulus is less than the above range, the head touch is good, but the durability is reduced. Furthermore, if the Young's modulus exceeds the above range, side effects will improve, but head touch will deteriorate.

The surface roughness (Rmax) of the substrate 2 is preferably 0.02 or less. If R max is in this range,
Spacing loss occurring between the head and the medium is reduced, and recording density can be increased. When R max exceeds the above range, it is difficult to obtain sufficient recording density.

It is preferable that R max as described above is achieved on both sides of the substrate 2, but the above effect can be obtained if it is achieved at least on the surface on which the magnetic layer is provided.

Note that the substrate 2 may contain a filler to reduce the coefficient of friction, if necessary.

When the substrate 2 is disk-shaped, its diameter may be selected as an appropriate value depending on the application, and is usually 50 to 130 mm.
That's about it. The thickness of the substrate 2 is about 7 to 80 μm when it is flexible, more specifically about 20 to 50 μm when used as a floppy disk, and about 7 to 15 μm when used as a magnetic tape. , that is, when used as a hard disk, 0.8~
It is about 2 mm.

A soft magnetic film 3 is provided on the substrate 2 .

The soft magnetic film 3 is provided to improve reproduction output.

The material constituting the soft magnetic film 3 is preferably a Fe-Ni alloy.

Examples of Fe-Ni alloy include Fe-NL alloy (Vermalloy). Fe-Ni-Mo alloy, Fe-Ni-Cr alloy,
Fe-Ni-Nb alloy, Fe-Ni-Mn-Cu alloy,
Fe-Ni-Mo-Nb alloy, Fe-Ni-Mo-Cu
An alloy, Fe-Ni-Si-Aj2 alloy, etc. can be preferably used.

In addition to the Fe-Ni alloy, a Fe-Co-■ alloy can also be preferably used.

In addition, Ti, Aff, and S are added to these alloys as necessary.
i. Mn. Cu. Ta,C. O. N, Ar, Ca. Cr
etc. may be contained.

The coercive force of the soft magnetic film 3 in the in-plane direction is preferably 6 to 200 e. When the coercive force is within this range, high reproduction output is obtained and modulation is reduced to 20% or less. If the coercive force is less than the above range, the reproduction output will improve, but the modulation will increase; if it exceeds the above range, the modulation will decrease, but the reproduction output will decrease.

The thickness of the soft membrane 3 is preferably 0.2 to 0.5 μm. If the film thickness is less than this range, productivity will improve, but sufficient reproduction output will not be obtained; if it exceeds this range, reproduction output will increase, but film formation will take time and productivity will decrease.

Note that the soft magnetic film 3 is preferably formed by a sputtering method.

Since the magnetic recording medium of the second aspect of the present invention performs perpendicular magnetic recording, the magnetic layer 4 is preferably a perpendicular E-type film having an axis of easy magnetization perpendicular to the film surface.

A preferable material for forming the magnetic layer 4 is a Co-Cr alloy. As the Co-Cr alloy, Co-
Cr alloy, Co-Cr-B alloy, Co-Cr
- Mn alloy, Co-Cr-Mn, 1B alloy, Co-
Cr-Ta alloy, Co-Cr-Si-A°C alloy, etc. are preferred.

Note that the Cr content in the Co-Cr alloy is 16 to 23
It is preferably about at%.

In addition to the Co-Cr alloy, a Co-V alloy can also be preferably used.

In addition, these alloys may contain O, N. Si. A
I2. Mn. Ar or the like may be contained.

The perpendicular coercive force of the magnetic layer 4 is preferably 400 De or more. If the vertical coercive force is less than this range, the reproduction output will be insufficient. Although there is no particular upper limit to the perpendicular coercive force, it can usually be easily manufactured up to about 15,000e.

The thickness of the magnetic layer 4 is preferably 0.05 to 0.2 μm. If the thickness is less than this range, the reproduction output will decrease and the S/N will decrease.

Moreover, when this range is exceeded, the recording density decreases, and for example, the recording density (Dso) does not reach 100 KFRPI.

The magnetic layer is preferably formed by a vapor phase deposition method, and particularly preferably by a sputtering method.

The solid protective layer 5 is made of 1 selected from metals or semimetals excluding rare earth elements including Y (Y means lanthanoid elements and actinide elements, hereinafter abbreviated as R).
contains at least one element, O and N, and further contains one or more elements selected from R for these elements.
It is preferable to contain up to 10 at%. Note that the solid protective layer is usually in a non-quality state.

The metals or semimetals other than R contained in the solid protective layer 5 include Si%AI2, Ti. Zn and B are preferable, and among these, it is preferable to make R and Si essential or to make Si and AI2 essential and include them in the solid protective layer 5.

In addition to these elements, Fe. Mg, Ca. Sr. B
a. Ar. Mn and the like may be contained in an amount of lat% or less of the total.

To explain in more detail, the composition of the solid protective layer 5 is preferably selected from the range of composition I or group II below.

LLL [Metal or semimetal that requires Si and Aβ] Si and An are usually contained in the form of oxides and nitrides.

The above compounds in the solid protective layer 5 may deviate from the stoichiometric composition.

Corrosion resistance is improved by containing these elements and oxygen and nitrogen.

The content of each element in the solid protective layer 5 in Composition I is preferably within the following range.

Si: 20 to 80 at%,
More preferably 40 to 70 at%.

A (2:1 ~ 30at%% More preferably 2 to 10 at%.

0: 2-3 0at%. More preferably 2 to 20 at%.

N: 5 to 45 at%, More preferably 15 to 35 at%.

The solid protective layer having such a composition further contains R, as described above.

As R, Y and a lanthanide element are preferable.

The content of R is 1 to 10 at%, preferably 2 to 8 at%, when the total of metals or metalloid elements other than R, O and N contained in the protective layer is 100 at%.
t%.

By containing R at such a content rate, durability, weather resistance, and corrosion resistance are further improved, and in particular, durability becomes extremely high.

In this composition, R is Y. La, Ce, Pr.
l of an element selected from the group consisting of Nd, Sm and Eu
It is preferable that Y is more than one species, and it is particularly preferable that Y is essential. The ratio of Y in R is preferably 50% or more.

At this time, better results can be obtained in terms of durability, weather resistance, corrosion resistance, etc.

Furthermore, when forming the solid protective layer 5 by the subac method,
By containing these elements in the target used, a dense target can be obtained, and as a result, the cooling efficiency of the target is improved and radiant heat during sputtering is suppressed.

R may be contained in the solid protective layer 5 in the form of either a simple element or a compound. When contained as a compound, it is usually preferably contained in the form of an oxide.

LL! L [Metal or metalloid that requires Si] R in this composition includes at least La and C.
It is preferable that one or more types of e are included.

La and Ce are usually contained as oxides.
The stoichiometry of these oxides is Laa O.
and C e O 2 , but other derivatives of these may also be used.

Ce-1; and La may be either one,
Both may be contained, but when both are contained, their quantitative ratio is arbitrary.

In addition to La and/or Ce, other rare earth elements including Y, such as Y. Although Er etc. may be contained,
The ratio of La and/or Ce in R is preferably 50% or more.

In addition to the rare earth element oxide, the solid protective layer 5 contains SL
Contains.

St is usually contained as an oxide or a nitride, but the stoichiometric composition may be deviated.

The content of each element in the solid protective layer 5 in composition H is preferably within the following range.

Si: 10 to 80 at%, more preferably 20 to 60 at%.

O: 10 to 80 at%, More preferably 15 to 60 at%.

N: 2 to 60 at%, More preferably 3 to 50 at%.

The content of R is the sum of metals or metalloid elements other than R contained in the protective layer, O, and N.
at% when bound, 1 to 10 at%, preferably 2 to 8
It is at%.

By containing R at such a content rate, durability, weather resistance, and corrosion resistance are improved, and in particular, durability becomes extremely high.

The content of each element in the solid protective layer S is Auger, ESC
A. It may be measured by SIMS or the like.

The formation of the solid protective layer 5 having such a composition is preferably carried out by a vapor phase deposition method, and particularly preferably by a sputtering method.

In the sputtering method, a sintered body having the above composition may be used as a target, or multi-source sputtering using two or more types of targets may be used. Additionally, reactive spatter can also be used.

Note that when containing La and/or Ce as the rare earth element, oxides of ignition alloys such as Auermetal, Hubermetal, Mischmetal, Welsbach metal, etc. can also be used as at least a part of the sputtering target.

In addition, other vapor phase deposition methods,
For example, it is also possible to use a CVD method, a vapor deposition method, an ion blating method, etc. as appropriate.

The solid protective layer 5 preferably has a Vickers hardness of 700 or more in order to ensure sufficient durability, but if the composition as described above in the present invention is selected, a Vickers hardness of 700 or more can be easily obtained. . In particular, when containing R, a Vickers hardness of 1000 or more can be obtained.

The thickness of the solid protective layer 5 is between 30 and 200, especially between 30 and 1
It is preferable to set the number to 00 people. If the thickness is outside the above-mentioned range, the protective effect will be insufficient, and if it exceeds the above-mentioned range, the spacing loss will increase, making it impossible to improve the recording density.

In the present invention, the contact angle of the surface of the solid protective layer 5 with water is 80" or less, preferably 60" or less, more preferably 4
It is preferably 0″′ or less.

By setting the contact angle with water within such a range, the lubricant III 6 can be uniformly formed. Note that the contact angle of the solid protective layer 5 with water is usually about 8° or more.

The contact angle with water may be measured, for example, after dropping pure water on the surface of the solid protective layer and 30 seconds later. The measurement atmosphere was 18
-23°C, about 40-60% RH.

The protective lubricant film 6 provided on the solid protective layer 5 is as described above.

The magnetic recording medium of the second aspect of the present invention having the configuration as described above is applied as a perpendicular magnetic recording medium to floppy disks, hard disks, magnetic tapes, and the like.

Furthermore, there are no particular limitations on the perpendicular recording magnetic head used for recording and reproducing the magnetic recording medium of the second aspect of the present invention;
The magnetic recording medium of the second aspect of the present invention particularly exhibits friction reduction and stabilization effects when used in combination with the thin film type perpendicular magnetic head.

As a thin film magnetic head, AA. O. A thin film magnetic pole layer made of a metal such as Co-Nb-Zr amorphous is formed on the above-mentioned ceramic substrate such as TiC, and then AAtO
It is preferable to use one coated with an inorganic protective film such as s.

The aforementioned protective lubricant film may be provided on the front surface of this head.

Note that the vertical magnetic head may be a floating type.

Example Hereinafter, the present invention will be explained in detail by way of practical examples.

[Example 1] <Preparation of magnetic disk sample> An aluminosilicate glass substrate with an outer diameter of 130 mm, an inner diameter of 40 mm, and a thickness of 1.9 mm was polished and further subjected to chemical strengthening treatment. The chemical strengthening treatment was performed by immersing it in molten potassium nitrate at 450°C for 10 hours.

Next, the surface of this glass substrate was smoothed by mechanochemical polishing. For mechanochemical polishing, a polishing liquid containing colloidal silica was used.

Glass substrates having different R max were produced by changing the polishing conditions. Table 1 shows the R max of the glass substrate used for each magnetic disk sample.

After cleaning these glass substrates, a magnetic layer was formed on the surface of each glass substrate in the following manner.

First, preliminary sputtering is performed in an Ar gas atmosphere, and F
e The oxide film on the target surface was removed. Then 02
A Feig4 film was formed by introducing gas and performing reactive sputtering. Note that the 02 gas was introduced so as to be blown onto the substrate.

The Fes04 film shape of each magnetic disk sample is P (
Arrow) and P.O. /P (^r+(h) is shown in Table 1.

After forming the FesO4 film, 1
Oxidation was carried out for ~5 hours resulting in γ-FeaOsla layers with different Rmax. The thickness of the magnetic layer was 2000.

Table 1 shows R max on the magnetic layer side of each magnetic disk sample.

Note that R max was measured using a stylus type surface roughness meter.

Perform X-ray diffraction on the magnetic layer of each sample. , an X-ray diffraction chart was created.

Note that X-ray diffraction was performed using the apparatus shown in FIG.

Table 1 shows the analysis results of the X-ray diffraction chart of each sample. Also, sample No. The X-ray diffraction charts of 1 and 2 are shown in FIGS. 5 and 6, respectively.

Furthermore, P (400) / P (311) and P (22
23/P(3113 changes are shown in FIG. 7.

Next, on the magnetic layer of each sample, 5 moles of C H s(C Ha) +, OH and CH
x (CHg) + aCOOCH 32 moles and C H s (
C H 2) l■ 10-4 mol/with 3 mol of COOH
2. A chloroform solution was prepared and used as a developing solution.

First, an object to be treated (a magnetic disk) was immersed in an aqueous phase, and then a developing solution was uniformly dropped onto the surface of the aqueous phase to develop a monomolecular film.

Next, the interface is compressed until the surface pressure reaches a predetermined pressure, and the object to be treated is raised almost vertically at a constant speed to transfer the monomolecular film onto the object to be treated, and a monomolecular film of 20λ is deposited. It was also used as a protective lubrication agent.

Regarding the magnetic disk samples thus obtained, CSS durability was measured by the following method. The results are shown in Table 1.

±i Main star △Δ ■Magnetic head used (magnetic head No. 1) Vickers hardness 2 2 0 0 kgf/mm2 A
After forming a thin film magnetic head element on a Q20m-T i C substrate, it was processed into a magnetic head shape and attached to a support spring (gimbal) to produce an air bearing type floating magnetic head. Rma of magnetic head flying surface
x is 130 people.

(Magnetic head No. 2) Si with Vickers hardness of 3000 kgf/mm2
Magnetic head No. 1 was used except that C substrate was used. It was produced in the same manner as 1.

The flying bite of these magnetic heads was adjusted to 0.1 μm by adjusting the slider width and gimbal load.

■CSS Using the above magnetic head, a CSS test was conducted at 25° C. and a relative temperature of 50%. CSS was performed by repeating the cycle shown in Figure 8. , CSS durability was measured by measuring the number of times until the recording/reproducing output decreased to less than half of the initial value, and was evaluated on the following five levels.

0: 10,000 times or more ○; 50,000 times or more and less than 100,000 times △: 20,000 times or more and less than 50,000 times ×: 10,000 times or more and less than 20,000 times xx: t less than 10,000 times The effects of the present invention are clear.

That is, the R of the magnetic layer side surface of the substrate and magnetic disk
Samples with max within the range of the present invention have high CSS durability, and also have P(400)/P(311) and P
(222)/PC311) within the range of the present invention, even when using a magnetic head with a high base hardness, C
Excellent SS durability.

[Example 2] Magnetic recording disk samples were prepared by changing the compounds contained in the protective lubricant film as shown in Tables 2 and 3. Sample No. prepared in Example 1 except for the protective lubricant film. Same as 2. Also, the magnetic head is No. l was used.

For these samples, the initial friction coefficient and the friction coefficient after durability running were measured.

Note that the protective lubricant film was formed as follows.

(LB method) A solution of 10 −4 mol/flood chloroform of the compounds shown in Tables 2 and 3 was prepared and used as a developing solution.

First, the object to be treated is immersed in the aqueous phase, and then developed and dissolved. The solution was evenly dropped onto the surface of the aqueous phase to develop a monolayer.

Next, the interface is compressed until the surface pressure reaches a predetermined pressure, and the object to be treated is raised almost vertically at a constant speed to transfer the monomolecular film onto the object to be treated, and then the object to be treated is lowered and raised. This process was repeated to accumulate a monomolecular film, forming a protective moisture film.

(Coating method) The compounds shown in Tables 2 and 3 were dissolved in chloroform and used as a coating solution. Concentration is 0.1wt% for dipping
In the case of Subin coat, the content was 0.2 wt%.

Ancestor JLI Rainbow Five Calendar above magnetic head No. 1, 20°C, 80% R
The coefficient of dynamic friction was measured at 1 rpm for 1 minute under H conditions.

The results are shown in Tables 2 and 3.

Using the above magnetic head No. 1 with Ir of '-'', contact running was performed at 100 rpm for 30 minutes at 20°C and 80% RH, and then dynamic friction was applied at 1 rpm for 1 minute. The coefficient was measured.

The results are shown in Tables 2 and 3. Note that the changes in the friction coefficient shown in Tables 2 and 3 are the minimum and maximum values during measurement.

Scraping of the protective lubricant film after the above-mentioned endurance running was visually observed.

From the results shown in Tables 2 and 3, the effects of the present invention are clear.

That is, the sample having the protective lubricant film of the present invention has a small coefficient of friction even after endurance running. Furthermore, by further adding ester, the coefficient of friction and its fluctuation after endurance running are reduced.

[Example 4] <Preparation of magnetic disk sample> A magnetic disk sample was prepared in the same manner as in Example 1 using a glass substrate having R max shown in Table 4.

However, P (Arrow) and P 02/ P (Ar+
02) are L X I O-”Torr and 0, respectively.
．． It was set as 058.

Further, the oxidation after the formation of the Fear 4 film was performed by heat treatment in the air under the conditions shown in Table 3 to form a γ-Fe20s magnetic layer. The thickness of the magnetic layer was 2000.

Table 4 shows the R max on the magnetic layer side of each magnetic disk sample.
Shown below.

The magnetic layer of each sample was subjected to X-ray diffraction in the same manner as in Example 1 to create an X-ray diffraction chart.

Table 4 shows the analysis results of the X-ray diffraction chart of each sample.

Also, sample No. 32 X-ray diffraction chart,
As shown in the figure.

As shown in Figure 9, this chart shows α-Fe2
A peak of surface index (104) of es was observed.

Further, the magnetic layer of this sample was analyzed using a low-incidence-angle X-ray diffractometer shown in FIG.
X-ray diffraction was performed at 2.0".

The obtained X-ray diffraction chart is shown in FIG.

As shown in FIG. 10, P(
104)/P(311) is P( at β=2.0°
104) / PC311) about 3 (@, a −F
It was confirmed that the content of ears was high on the surface side of the magnetic layer.

Note that when similar measurements were performed on other samples shown in Table 4, almost the same results were obtained.

Next, the same lubricant film as in each sample of Example 1 was formed on the magnetic layer of each sample.

The sliding durability and reproduction output of the magnetic disk samples thus obtained were measured by the following methods. The results are shown in Table 4.

After forming a thin film magnetic head element on an Aj20a-TiC substrate with a Vickers hardness of 2 200 kgf/+++ m2, it was processed into the shape of a magnetic head and attached to a support spring (gimbal). An air bearing type floating magnetic head was fabricated.

The Rmax of this magnetic head floating surface was 130 people.

The slider width was 150 um, and the gimbal load was 25 g.

(Sliding Durability) Using the above magnetic head, a sliding durability test was conducted at 25° C. and 50% relative humidity.

The above magnetic head is pressed against the magnetic disk sample, and the relative speed between the magnetic disk and the magnetic head is 20 m/
The magnetic disk was rotated so that At this time, it was confirmed by an AE (acoustic emission) sensor that the magnetic head was constantly sliding without floating.

Durability was evaluated based on the time until scratches appeared on the magnetic disk.

0: 60 minutes or more ○: 40 minutes or more and less than 60 minutes △: 20 minutes or more and less than 40 minutes ×: less than 20 minutes This sliding durability test is a more severe durability test method than the CSS durability test. .

The reproduction output of each sample shown in Table 4 was measured to examine the decrease in reproduction output due to the inclusion of α-Fears.

The evaluation was conducted using sample No. 2, which does not contain α-Fe2r. 3
The reproduction output of No. 1 was set to 100, and ○: 90 or more ×: less than 90.

From the results shown in Table 4, the effects of the present invention are clear.

In addition, when a CSS durability test was conducted on each of the above samples, the same tendency as in the sliding durability test was observed.

In addition, for each sample shown in Table 4, the initial friction coefficient and the friction coefficient after endurance running were measured in the same manner as in Example 3. Similar results were obtained for each sample.

Further, each of the above lubricant films was formed on the front surface of the magnetic heads used in Examples 1 to 4, and measurements similar to those described above were performed in combination with each of the magnetic disk samples prepared in Examples 1 to 3.

As a result, when combined with a magnetic disk having a lubricating film, the effect was further improved than in the above embodiment.

[Example 5] Various magnetic disk samples having the configuration shown in FIG. 11 and having different solid protective layer compositions were produced. The details of the configuration of each part are shown below.

[Substrate diameter 86 mm, thickness 40 μm, Young's modulus 900 kgf/mm”, surface roughness (Rmax
) 0.015 μm polyimide was used.

[D in an Ar atmosphere of 2X10-'Pa containing soft magnetic 11I1 2%02
80at%Ni-Fe by C magnetron sputtering method
The alloy was formed into a film having a thickness of 0.45 gm.

The coercive force of the soft magnetic film in the in-plane direction was 90e.

[Magnetic layer] 2 oat% Cr due to DC magnetron spa/sota removal
-Co alloy was formed into a film with a thickness of 0.18 um.
The atmosphere during film formation was the same as that for forming the soft magnetic film.

The perpendicular coercive force of the magnetic layer was 7200e.

[Solid protection N] In an Ar atmosphere of IXIO-'Pa containing 2% 02, R
By removing the F magnetron scatter, solid protective layers having various compositions shown in Table 5 below were formed to a thickness of 0.01 μm.
Note that the target used for sputtering was a sintered body having a composition corresponding to the solid protective layer.

Table 5 shows the Vickers hardness of each solid protective layer. The Vickers hardness was measured using a film formed to a thickness of 2 LLm under the same conditions as the solid protective layer of each magnetic disk sample.

[Protective lubricant film] Protective lubricant film of Example 1 The following tests were conducted on each of the obtained samples.

(1) Durability test A A needle scratch test was conducted to evaluate durability.

The radius of curvature of the needle tip is 100 μm, the load is log, and the relative speed between the needle and sample is 10? 0 in m/sec Durability was evaluated based on the width of scratches present on the sample surface after the test.

At this time, if the width of the scratch exceeds 5 μm, problems will arise in practical use, and the width is preferably 3 μm or less.

(2) Weather resistance test After storage for 100 days under conditions of 70° C. and 90% RH, the size of speckled stains that appeared on the surface of the magnetic layer was measured.

(3) Measurement of electromagnetic conversion characteristics Magnetic pole thickness 0.2 μm. Using a main pole excitation type single pole thin film head with a magnetic pole width of 50 LLm, the relative speed between the head and the disk is 2.
The f characteristic was measured in m/sec and evaluated by Dso.

The thin film head has eight parts. 0. -Co-Nb on TiC substrate
A -Zr amorphous magnetic pole and an Af2203 protective film were formed by a spatter method.

(4) Head wear test A The head and disk were tested at a load of 10 g and a relative speed of 2 m.
/sec, and the amount of head wear after 1000 hours was measured. The amount of head wear was determined by measuring the shape of the head at the start of running and 1000 hours after the start of running using a stylus type surface roughness meter, and comparing these measurements.

The head used was the thin film head shown in (3) above, and the worn parts were mainly the magnetic pole and the protective film.

The results of these tests are shown in Table 5.

From the results shown in Table 5, the effects of the present invention are clear.

That is, samples in which the composition of the solid protective layer was within the range of the present invention gave good results in each test. On the other hand,
Samples with solid protective layers having compositions with R contents of less than lat% and greater than 1Oat% had poorer performance.

[Example 6] Same as Example 5 except that the solid protective layer forming method was changed,
Various magnetic disk samples were prepared. The method for forming the solid protective layer is shown below.

[In an atmosphere containing solid protective layer Ar, 02 and/or N2,
By the RF magnetron back method, a solid protective layer having various compositions and contact angles shown in Table 6 below was formed to a thickness of 0.01 mm.
It was formed in μm.

In addition, the Ar pressure is IXIO-'Pa, and 1-10
The contact angle was changed by adding %02 and/or N2. Note that among the samples shown in Table 6, those with contact angles exceeding 80' were formed by adding only 02.

The contact angle was measured 30 seconds after dropping pure water onto the surface of the solid protective layer. The atmosphere during contact angle measurement was 20°C, 55°C.
%RH.

The target used for sputtering was a sintered body having a composition corresponding to the solid protective layer.

Table 6 shows the Vickers hardness of each solid protective layer. The Vickers hardness was measured using a film formed to a thickness of 2 μm under the same conditions as the solid protective layer of each magnetic disk sample.

In addition to the (2) weather resistance test and (3) measurement of electromagnetic conversion characteristics in Example 5, the following tests (5) and (6) were conducted on each sample thus obtained.

(5) Durability Test B Each sample was mounted on a floppy disk drive for perpendicular magnetic recording, and the number of buses when the output decreased to 70% of the initial output was determined.

A thin film head for perpendicular recording is used as the magnetic head, and the load is log. The sliding speed was 2 m/s.

(6) Head Wear Test B In (4) Head Wear Test A of Example 5, the sliding conditions were made more severe.

That is, the head and disk were slid at a load of 15 g and a relative speed of 2 m/sec, and the amount of head wear after 1000 hours was measured.

The amount of head wear is measured at the start of running and 1 000 at the start of running.
The shape of the head after a certain period of time was measured using a stylus type surface roughness meter, and the results were compared.

The results of these tests are shown in Table 6.

From the results shown in Table 6, it can be seen that the contact angle of the solid protective layer is 80'
It can be seen that the results of each test are favorable when the following values are met.

[Example 7] Various magnetic disks were manufactured by changing the composition of the protective lubricant film as shown in Tables 7 and 8. Example 6 except for the protective lubricant film
Sample No. prepared in Same as 52.

However, a glass substrate was used as the substrate.

A glass substrate was produced as follows.

An aluminosilicate glass plate with an outer diameter of 130 mm, an inner diameter of 40 mm, and a thickness of 1.9 mm was polished and further subjected to chemical strengthening treatment. The chemical strengthening treatment was performed by immersing it in molten potassium nitrate at 450°C for 10 hours.

Next, the surface of this glass plate was smoothed by mechanochemical polishing. For mechanochemical polishing, a polishing liquid containing colloidal silica was used. Next, it was washed to obtain a glass substrate.

The surface roughness of the glass substrate thus obtained (Rma
x) was 50 people.

For these test samples, the initial friction coefficient and the friction coefficient after endurance running were measured.

Side 11 Elephant 1'' L number Using the magnetic head used in (3) measurement of electromagnetic conversion characteristics in Example 5, the coefficient of dynamic friction was measured at 20° C. and 60% RH atmosphere at 1 rpm for 1 minute.

The results are shown in Tables 7 and 8.

,'-',,i,, After performing contact running at 100 rpm for 30 minutes at 20°C and 80% RH atmosphere using the same magnetic head as above, the coefficient of kinetic friction was determined for 1 minute at 1 rpm. was measured.

The results are shown in Tables 7 and 8. Note that the changes in the friction coefficient shown in Tables 7 and 8 are the minimum and maximum values during measurement.

From the results shown in Tables 7 and 8, the effects of the present invention are clear.

Effects of the Invention> According to the present invention, a magnetic recording medium with high runnability and durability and a highly reliable magnetic recording and reproducing method are realized.

[Brief explanation of drawings]

FIGS. 1 and 11 are partial cross-sectional views showing preferred embodiments of the magnetic recording medium of the present invention, respectively. ? FIG. 2 is a schematic diagram of an X-ray diffraction apparatus. FIG. 3 is a schematic diagram of a low-incidence-angle X-ray diffractometer. FIG. 4 is a partial sectional view of a magnetic head used in the present invention. FIGS. 5 and 6 are X-ray diffraction charts of the γ-FeaOa magnetic layer. Figure 7 shows the changes in P(400)/P(311) and P(2
22)/P(311). FIG. 8 is a graph showing one cycle of CSS. FIG. 9 is an X-ray diffraction chart of the γ-Fe20s magnetic layer. FIG. 10 is an X-ray diffraction chart of the γ-Fea03Eet layer prepared using a low incident angle X-ray diffractometer. Explanation of symbols 1...Magnetic recording medium 2...Substrate 3...Soft magnetic film 4...Magnetic layer 5...Solid protective layer 6...Protective lubricant film 10...Magnetic head 101. ... X-ray source 102 ... Magnetic recording medium 103 ... Counter tube DS ... Divergence slit SS ... Scatter slit RS ... Receiving slit MM ... Monochromator S1, S2 ... ...Solar Slit petition doujin TDC Corporation Patent attorney Yo Ishii

Claims (6)

[Claims] (1) Using a magnetic head with a ceramic base,
A method for recording and reproducing information on a magnetic recording medium having a continuous thin film magnetic layer, the method comprising: containing an alcohol having a melting point of 30° C. or more on the magnetic layer and/or the magnetic head, and further containing a fatty acid and an ester. 1. A magnetic recording and reproducing method characterized by having a protective lubricating film. (2) The magnetic recording and reproducing device according to claim 1, wherein the magnetic layer has iron oxide as a main component, the magnetic recording medium has the magnetic layer on a rigid substrate, and the magnetic head is of a floating type. Method. (3) The magnetic recording and reproducing method according to claim 1, wherein the magnetic layer is a perpendicularly magnetized film, and a solid protective layer is provided in contact with the perpendicularly magnetized film. (4) The ceramic substrate has a Vickers hardness of 10
4. The magnetic recording and reproducing method according to claim 1, wherein the magnetic head has a thin film pole layer on the ceramic substrate. (5) A continuous thin film magnetic layer containing γ-Fe_2O_3 as the main component is provided on a rigid substrate, and in the X-ray diffraction chart of this magnetic layer, the plane index of γ-Fe_2O_3 is (400), the plane index (22
2) and the respective peak areas of surface index (311) are P(400), P(222) and P(311), 0≦P(400)/P(311)≦1.0 0≦P (222)/P(311)≦0.5, and the surface roughness (Rmax) of the rigid substrate is 10 to 100 Å.
, the surface roughness (Rmax) of the magnetic layer side surface is 50 to 200 Å, and a protective lubricant film containing alcohol with a melting point of 30° C. or more and a fatty acid is provided on the magnetic layer. Features of magnetic recording media. (6) A magnetic recording medium in which a soft magnetic film, a perpendicular magnetization film, a solid protective layer, and a protective lubricant film are provided in this order on a support, the solid protective layer being R (where R is Y represents one or more elements selected from rare earth elements including ~1
A magnetic recording medium containing 0 at% R, wherein the protective lubricant film contains an alcohol having a melting point of 30° C. or higher, and further contains a fatty acid and an ester.