JPH02276018A - Magnetic recording and reproducing method and magnetic recording medium - Google Patents

Abstract

PURPOSE:To decrease the friction between the magnetic recording medium and a magnetic head and to decrease the fluctuation thereof during durable traveling by providing a specific protective lubricating film on a magnetic layer and/or the magnetic head. CONSTITUTION:The magnetic recording medium 1 has the magnetic layer 4 of a continuous thin film type on a rigid substrate 2 and the protective lubricating film 6 is provided on this magnetic layer 4. The substrate 2 is formed by using surface tempered glass to withstand a heat treatment at the time of the formation of the magnetic layer 4 and for the purpose of controlling the surface roughness thereof. The magnetic layer 4 of the continuous thin film type essentially consisting of, for example, gamma-Fe2O3 is formed on the rigid substrate 2. The protective lubricating film 6 contg. alcohol with >=30 deg.C m.p. is installed on the magnetic layer 4. The magnetic recording medium having the high traveling property and durability is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a magnetic 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 N1-P underlayer on an Aρ-based disk-shaped metal plate, or by oxidizing the surface of this metal plate to form alumite. It is generally constructed by sequentially depositing a Cr layer, a metal magnetic layer such as Co--Ni, and a protective lubricant film such as C by sputtering.

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. 62-43819, are chemically stable, so there is no fear of corrosion, and they also have sufficient hardness. There is.

On the other hand, a flying type magnetic head is a magnetic head having a slider that generates buoyancy, and 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 is usually used.

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 type magnetic head, the base body functions as a slider.

In these floating magnetic heads, the slider is made of various ferrites, Ant Ox -T i C1Zr0□,
It is composed of various ceramics such as SiC and AβN.

In a magnetic disk device using a floating magnetic head, the floating surface of the floating magnetic head (the surface of the slider on the magnetic disk side) comes into contact with the magnetic disk during contact start/stop (C3S). 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 No. 62-43819, even if a lubricating film is formed on the surface of the magnetic disk. Or even if a protective film is provided, the head floating surface is easily scratched due to repeated C8S.
Furthermore, friction between the head and the disk tends to increase. Therefore, in such a combination, care must be taken in selecting the materials constituting the lubricating film or the protective film.

Moreover, a magnetic disk having an iron oxide magnetic layer and M n −
When used in combination with a floating head having a base made of Zn ferrite, such a problem becomes even more pronounced because the hardness of MnZn ferrite is lower than that of iron oxide.

Furthermore, for thin-film magnetic disks with iron oxide magnetic layers, Aj2t 0, which has higher hardness than Mn-Zn ferrite,
3-When using a floating magnetic head having a substrate of TiC, Zr0t, SiC, Aj2N, etc., the above-mentioned problems are solved to some extent, but in such a combination of a magnetic disk and a floating magnetic head, the magnetic layer and the slider both have high hardness, which requires higher lubrication and protection effects. In particular, when a thin-film floating magnetic head is used for high-density recording, the above problem becomes more pronounced.

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 bite) 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 C8S 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 The roughness is extremely 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 C8S 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, demagnetization occurs due to the action of the demagnetizing field in the magnetic layer, making it impossible to increase the recording density by more than a -window. It is difficult.

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 sputtered 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 magnetic head has a magnetic pole, a protective film, etc. 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 helad touch under high-speed recording and readout.

■High playback output.

■Low occurrence of modulation.

■High productivity.

etc.

In order to satisfy such performance, the present inventors developed a perpendicular magnetic recording medium that has a substrate, a soft magnetic film, a magnetic layer, a protective layer, and a lubricant layer in this order, and improved the physical properties and constituent materials of each component. We are proposing to limit the
197028).

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 one or more elements selected from metals or semimetals excluding ), O and N, and further containing 1 to 10 at% 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 conventional protective lubricating films.

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).
In other words, stick-slip occurs (<, the magnetic head is less likely to be attracted to the magnetic recording medium, and the magnetic head and magnetic recording medium are less likely to be scratched or damaged).
An object of the present invention is to provide a magnetic recording medium and a magnetic recording/reproducing method using the same.

Means for Solving the Problems> Such objects are achieved by the following inventions (1) to (9).

(1) Using a magnetic head with a ceramic base,
A method for recording and reproducing on a magnetic recording medium having a continuous thin film magnetic layer, characterized in that a protective lubricant film containing alcohol with a melting point of 30° C. or higher is provided on the magnetic layer and/or the magnetic head. A magnetic recording and reproducing method.

(2) The magnetic recording and reproducing method according to (1) above, wherein the protective lubricant layer further contains an ester.

(3) In the above (1) or (2), 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. The described magnetic recording and reproducing method.

(4) The magnetic recording and reproducing method according to (1) or (2) above, wherein the magnetic layer is a perpendicular magnetization film, and a solid protective layer is provided in contact with the perpendicular magnetization film.

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

(6) A continuous thin film magnetic layer mainly composed of γ-Fears is provided on a rigid substrate, and in the X-ray diffraction chart of this magnetic layer, Y-Fe, O
, the peak areas of plane index (40,0), plane index (222), and plane index (311) are P(400),
When P(222) and P(311), 0≦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 lubricant film containing alcohol having a melting point of 30° C. or higher on the magnetic layer.

(7) The magnetic recording medium according to (6) above, wherein the protective lubricant layer further contains an ester.

(8) A magnetic recording medium in which a soft magnetic film, a perpendicularly magnetized magnetic layer, 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 , represents one or more elements selected from rare earth elements including Y. 1 to 1 for
A magnetic recording medium containing 0 at% R, wherein the protective lubricant film contains alcohol having a melting point of 30° C. or higher.

(9) The magnetic recording medium according to (8) above, wherein the protective lubricant film further contains an ester.

<Function> In the present invention, on the continuous thin magnetic layer of the magnetic recording medium and/or
Or melting point 30℃ on the ceramic substrate of the magnetic head.
It has a protective lubricating film of alcohol.

The action of this protective lubricant film reduces the coefficient of friction between the magnetic recording medium and the magnetic head, and also reduces friction fluctuations.
In order to prevent stick-slip and film deterioration during durability running, it prevents damage to the medium and head when the magnetic head contacts the medium, and prevents the head from adhering to the surface of the medium.

Among these, in particular, the effect of reducing initial friction and the effect of reducing friction fluctuation after endurance running are the effects of solid or semi-solid media in a system using a medium with a continuous thin film magnetic layer and a thin film head with a ceramic substrate. This is the effect that alcohol selectively exerts.

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.

Nitrate, sulfate, etc. are used as the salt, 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 of using KNOI as an alkali molten salt and exchanging K ions with Na ions in the glass, and a method of exchanging Li ions in the glass with NaNO3. 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 number of participants is 100 people, preferably 40 to 80 people, and even more preferably 40 to 60 people. By setting the Rmax of the rigid substrate within this range, the durability of the magnetic recording medium is improved, and the Rmax of the surface on the magnetic layer side of the medium as described later is
can be easily obtained.

Note that Rmax 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 polishing 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 polishing, it is preferable to use glass that does not contain crystalline substances. This is because the grain boundaries are polished relatively quickly by mechanochemical polishing, making it impossible to achieve the above Rmax.

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-Fi1!201 as a main component is formed.

When this magnetic layer is subjected to X-ray diffraction, the peak area of each of the plane index (400), plane index (222), and plane index (311) of γ-Fe2em is P(400) in the X-ray diffraction chart. , P(222) and P(31
1), 0≦P(400)/P(3111≦1
．． 00≦P(222)/P(3), 1)≦0. 5, more preferably 0≦P(400)/P(311)≦0.60≦P(2
22)/P(311)≦0.3.

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

By having such a peak area ratio and Rmax, durability is improved, and in particular, C8S durability is improved.

To explain in more detail, an increase in P(222) means that the (222) plane and (111) plane are parallel to the magnetic layer plane.
) shows that the proportion of surfaces that exist increases. γ-
Fe2O3 has a spinel 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 (111) plane is large, that is, P(222)/P(311)
If the value of is large, the γ-Fears constituting the magnetic layer are likely to slip due to sliding with the magnetic head, and it is considered that durability is reduced.

When P(222)/P(311) exceeds the above range, durability is critically reduced.

The (100) plane that exists parallel to the (400) plane is (111)
) is considered to be the second most prone to slipping, so P(4
00)/P(311) exceeds the above range, durability is critically reduced.

Moreover, if Rmax of the magnetic layer side surface is within the above range,
In addition to improved durability, recording and reproducing can be performed while maintaining the distance between the surface of the magnetic layer and the floating surface of the floating magnetic head to 0.1 μm or less, and the attraction between the floating magnetic head and the magnetic recording medium is improved. High-density recording is possible.

Further, in the present invention, it is preferable that the magnetic layer contains α-FeJs. Durability is improved by containing α-Fears in the magnetic layer.

When the magnetic layer containing α-Fears was subjected to X-ray diffraction, in the X-ray diffraction chart, a-Fe
The peak area of the plane index (104) of 20a is P(104)
When, preferably 0.02≦P(104)/P
(311)≦0.20, more preferably 0.05≦P(104)/P(311)≦0.15.

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

To explain in more detail, when P(104)/P(311) is less than the above range, the durability improvement effect is relatively low, and when it exceeds the above range, 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, the X-rays irradiated from the X-ray source 101 are
Magnetic recording medium 10 via divergence slit DS
It is incident on the magnetic layer of No. 2 and diffracted, and the scatter slit S
After passing through S and receiving slit RS, it is reflected by a monochromator MM to become monochromatic light, and then passes through a receiving slit R3 and enters a counter tube 103, where the X-ray intensity is counted. recorded.

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-FeiOx is 33
．． It appears around 3°, and the surface index of γ-Fetus (400
), plane index (222) and plane index (311), respectively, have peaks of 43.5”, 37.3° and 35.
Appears around 6". 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-Fe2eg in this way, it is possible to further strengthen the surface part of the magnetic layer, which is easily damaged by the sliding of the magnetic head, and it is possible to further strengthen the surface part of the magnetic layer, which is easily damaged by the sliding of the magnetic head. The content of 820 g of α-F can be kept low.

In this case, 20 g of α-Fe 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 20 g of α-Fe 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 FIG. 3, the X-rays irradiated from the X-ray source 101 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 R8, 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 /dt.

In this device, by changing the angle β between the incident X-ray and the magnetic layer surface, α-
Feign's distribution can be obtained. Specifically, in order to analyze a portion close to the surface, it is sufficient to set β small; as β becomes larger, analysis results deeper into the magnetic layer can be obtained.

In the present invention, in such low incident angle X-ray diffraction, β
It is preferable that the smaller P(104)/P(311) becomes larger. For example, P(104)/P(311) measured when β=0.5° becomes smaller than P(104)/P(311) measured when β=2.0°. 1.5 of P(104)/P(311)
It is preferably 1.5 to 5 times, particularly 1.5 to 5 times.

The continuous thin film type magnetic layer whose main component is γ-F820g is
First, Fe5O4 is formed, and this Pe5o< is oxidized to form γ
-FeJs is preferably formed.

The method for forming Fe104 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 reactive sputtering to deposit Fe5O on a substrate.
This is a method of directly forming 4. Direct methods include an oxidation method using Fe as a target in an oxidizing atmosphere, a reduction method using 20 g of α-Fe as a target and using a reducing atmosphere, and a neutral method using Fe5Oa as a target. In the present invention, it is preferable to use the oxidation method because sputter control is easy and the film formation rate is high.

In the oxidation method, sputtering is performed by adding 02 gas as a reactive gas to an Ar gas atmosphere.

In order to obtain the above-described peak ratio of γ-Fears in X-ray diffraction, the partial pressure Po2 of 0□ gas and the total pressure P (Ar+(hl) of Ar gas and 02 gas are preferably , especially preferably.

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 (Ar+O□) in the present invention is I
X 10-' to I X 10-''Torr,
In particular, 5 x 10-' to 8 x 10-'' Torr.

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

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

For details on Fe504 thin film formation by direct method, see Journal of the Institute of Electronics and Communication Engineers '80/9 Vol. J63-CNo. 9 p.
, 609-616, and in the present invention, it is preferable to form the magnetic layer according to this method, and at that time, it is preferable to perform sputtering at a partial pressure of 0□ as described above.

In addition, the indirect method uses Fe as a target to form α-FeJa in an oxidizing atmosphere, and then reduces it to Fe3O4.
This is the way to obtain.

Fe50+ deposited by sputtering is γ-Fet
oxidized to US.

This oxidation occurs at a partial pressure of 02 gas of about 0.05 to 0.8 atm.
The heat treatment may be carried out in an atmosphere with 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 to 400°C, especially 25°C.
The temperature is preferably 0 to 350°C, and the temperature holding time is preferably 10 minutes to 10 hours, particularly 1 hour to 5 hours.

In order to easily obtain the peak area ratio as described above for 20 g of α-Fe, the heating rate must be set at 3.5 to 3.5
b b 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 holding temperature.

Further, when performing this heat treatment, Rmax on the magnetic layer side of the magnetic recording medium can be set within the above range by controlling the heat treatment temperature and time.

The magnetic layer formed in this way has a coercive force of 400 to 2
0000e, residual magnetization of 2000 to 3000 G, and magnetic properties of about 0.55 to 0.85 are obtained. Furthermore, there is almost no deterioration in magnetic properties due to the inclusion of α-Fe2O3.

Co, Ti, Cu, etc. may be added to the magnetic layer as necessary, and Ar, etc. contained in the film forming atmosphere may be contained.

The thickness of the magnetic layer is set at 50 mm in consideration of productivity, magnetic properties, etc.
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.

Alcohol having a melting point of 30° C. or higher is used for this protective lubricating film. Examples of such alcohols include the following.

As a monohydric saturated alcohol, CH-(CH2)+□0H CH, (CHI),,0H CH-(CHa) 1aOH CHs (CHz) +-0H CHs (CHI)+. 0H CHs (CHi) *+0H CHs (CHi) *5OH CHs (CHg), 0H CHI (CH2)*tOH CH, (CH,), CHOHC'H.

CHs (CHt) + s CHOHCHsCH
a (CHZ) I? CHOHCHa et al.

Monohydric or polyhydric natural alcohol, synthetic alcohol, etc.

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

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

The protective lubricating film may further contain one or more esters.

By adding ester, the fluctuation in friction after endurance running becomes even smaller.

Esters that can be suitably used include the following.

A, ester with a melting point of less than 30°C; C,,H,,C00CH.

C,,H,,C00CH.

C,,H2ICOOC,H8 C, aHaycOOcJs C1sH*+C00CJs C,,H2,C00C4H.

C,,H2,C00C4H.

C, @H31cOOc4H.

C,7H,,C00C4H.

C+-H-ycOOcsH C,? HssCOOC8H.

CHs (CHa)tcH”c)I(CH2)ycOo
(CHi)s-CH=CH(CHz)*CHx CH-(CHz)? CH:CH(CHz)7Coo(C
H-)*CHsCH3(CHz)tcH(CHt), C
00C) lacH(CH-)-OCO(CH,), CH
=(:H(CH,), CH.

B, ester with a melting point of 30°C or higher; CH, (CH,)　,4COOC)I.

CHI(CH,,,C00CR.

GHsCCHx +=C00CHz CHs (CH2□.C00CH.

CH-(CHz)a4cOOcHs CH-(CH21acOOcJs CHI(CH2,,C00C,H.

CHs(CH2)+5COOCalt and others Among these,
Preferably linear monovalent saturated or unsaturated carbon number of 1
It is a fatty acid ester of a fatty acid having 2 to 38 carbon atoms and a linear monovalent saturated or unsaturated alcohol having 3 to 30 carbon atoms in total.

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

It is preferable that one or more esters are mixed with the alcohol in a molar ratio of 9 or less, particularly in a molar ratio of 1 to 9.

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

There are no particular restrictions on the method for forming the protective lubricant film, and any suitable method may be selected from among the Langmuir-Prodgett (LB) method, coating method, and the like.

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 without compressing the interface to maintain a constant pressure. Then, transfer the monomolecular film onto the adherend substrate. Next, the attached water is dried as necessary. Furthermore, if necessary, a cumulative film is obtained 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 for the solution developed 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 and trobenzene, etc.), alcohols (ethyl alcohol, methyl alcohol,
propyl alcohol, etc.), ketones (acetone, etc.),
Examples include heterocyclic compound type (quinoline etc.), amine type, ether type, ester type, acid type and the like.

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

When using the coating method, the developing solution used in the LB method described above can be used as the coating solution. Further, as the coating method, spin cord, dipping, spray coating, etc. may be selected as appropriate.

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. If used,
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 IO shown in FIG.
and a protective layer 70 in this order. Further, 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, Rmax of the front surface is 200 Å.
Hereinafter, it is particularly preferable that the number of participants be 50 to 150 people. A magnetic head having such Rmax and the above-mentioned R m
By using it in combination with a magnetic recording medium having ax, the effects of the present invention are further improved.

The material of the coil layer 60 is not particularly limited, and a commonly used metal such as octabeta 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, in addition to the spiral type shown in the figure, the winding pattern is a 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 1000.
kgf/mm” or more, especially 1000 to 3000 kgf/
It is preferable to be made of a ceramic material with a size of about mm2. With this configuration, the effects of the present invention become even more remarkable.

Ceramic materials with a Vickers hardness of 1000 kgf/mm2 or more include ceramics whose main component is Al2xOs-TiC, ceramics whose main component is ZrO□, ceramics whose main component is SiC, or 6
Ceramics containing 42N as a main component are suitable. These also contain Mg, Y, Zr0t,
T i 02 etc. may be contained.

Among these, those particularly suitable for the present invention are All! 2
Ceramics containing 0s Tic as a main component, ceramics containing SiC as a main component, or ceramics containing AfiN as a main component are the most preferred among these, and the most suitable one is one that has the same hardness as the thin film magnetic layer containing iron oxide as a main component. Since the relationship is optimal, it is a ceramic whose main component is Aβ*Os-Tic.

Any conventionally known material can be used for the lower and upper magnetic pole layers 41, 45, such as permalloy, sendust, CO-based amorphous magnetic alloy, and the like.

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 layer 41 and the upper magnetic pole layer 45.

The gap layer 50 is made of A(1wOs, SiO□
It may be a known material such as.

The patterns, film thicknesses, etc. of the pole layers 41, 45 and the gap layer 50 may be any known ones.

Furthermore, in the illustrated example, the coil layer 6o is of a so-called spiral type, and the upper and lower magnetic pole layers 41 are arranged in a spiral shape.
．． 45, and an insulating layer 33.35 is provided between the coil layer 60 and the upper and lower magnetic pole layers 41.45.

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 forming a thin film by sputtering, SiO2, glass, /'1I220. etc. can be used.

Further, a protective layer 70 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, β20S can be used. Further, various resin coat layers or the like may be laminated thereon.

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

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 sputtering 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.

Disc rotation speed is about 200 C1 ~ 6000 rpm,
In particular, the speed is 2000 to 4000 rpm.

In addition, the flying height is 0.2 p or less, especially 0.15 μ or less, and even 0.1 or less, for example 0.01 to O, C9, +n.
At this time, good flying characteristics and C8
S durability can be obtained.

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

Furthermore, when a protective lubricant film as described above is formed on the front surface of the magnetic head, the C8S 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.
8S 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 film 6 on a substrate 2 as a support in this order.

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, these 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 is AI2. , Ti or other metals, or 5iOi, Six N4. A sputtered film of AAiOs, an inorganic oxide, nitride, or a mixture thereof such as a material constituting the solid protective layer to be described later is suitable, and a coated back coat layer may 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 constituent material, but polyimide, polyethylene terephthalate (
It is preferable to select from polymer materials such as PET), polyphenylene sulfide (PPS), polyamide, polyethylene naphthalate (PEN), and polyetheretherketone (PEEK), which have good heat resistance, dimensional stability, surface roughness, etc. Therefore, among these, 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 A°C, A2 alloy, various resins such as polyimide, polycarbonate, etc.
Among these, it is more preferable to use glass because it has good moldability in terms of heat shrinkage rate, surface roughness, etc.

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 preferable that it is ~1000 kgf/mm''. By setting the Young's modulus within this range, durability is improved and the head touch is good. When the Young's modulus is less than the above range, the head touch is good. However, when the Young's modulus exceeds the above range, the durability improves, but the head touch deteriorates.

The surface roughness (Rmax) of the substrate 2 is preferably O,o24 or less. When Rmax is within this range, the spacing cross that occurs between the head and the medium is reduced, and the recording density can be increased. When Rmax exceeds the above range, it is difficult to obtain sufficient recording density.

The above Rmax is preferably achieved on both sides of the substrate 2, but the above effect can be obtained if it is achieved at least on the surface where 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.

Fe-Ni alloys include Fe-Ni alloy (permalloy), Fe-Ni-Mo alloy, Fe-Ni-Cr alloy,
Fe-Ni-Nb alloy, Fe-Ni-Mn-Cu alloy,
Fe-Ni-Mo-Nb alloy, Fe-Ni-M
o -Cu alloy, Fe-Ni-31-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, these alloys may contain Ti, A℃, S
i, Mn, Cu, Ta, C, OlN, 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 200e. 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 magnetic film 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 sputtering.

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 magnetization film having an axis of easy magnetization in a direction perpendicular to the film surface.

A preferable material for forming the magnetic layer 4 is a Co-Cr alloy. As a Co-Cr alloy, Go-
Cr alloy, Co-Cr-B alloy, Co-Cr-M
n alloy, Co-CrM n -B alloy, Go-Cr-T
a alloy, C.

Cr-3i-Al1. Alloys and the like are preferred.

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

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

In addition, these alloys include OIN, SL, A
12, Mn, Ar, etc. may be contained.

The perpendicular coercive force of the magnetic layer 4 is preferably 4000e 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 (D, . . . ) does not reach 100 KFRPI.

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

The solid protective layer 5 includes one or more elements selected from metals or semimetals excluding rare earth elements (Y means rank-made elements and actinide elements, hereinafter abbreviated as R) including Y, and O. and N, and further contains one or more elements selected from R for these elements.
It is preferable to contain 10 at%. Note that the solid protective layer is usually in an amorphous state.

The metal or metalloid other than R contained in the solid protective layer 5 is preferably Si, Al2, Ti, Zn, and B. It is preferable to make it contain in 5.

In addition to these elements, Fe, Mg, Ca, Sr%B
A, Ar, Mn, etc. may be contained in an amount of about 1 at% or less of the total.

More specifically, the composition of the solid protective layer 5 is preferably selected from the following range of compositions or compositions II.

! LLL [Metal or semimetal that requires Si and A° C.] Si and Afl 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 the composition process is preferably within the following range.

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

Al1: 1 to 30 at%, More preferably 2 to 10 at%.

O: 2 to 30 at%, 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 sum of metals or metalloid elements other than R contained in the protective layer, and O and N 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.

R in this composition includes Y, La, Ce, Pr,
1 of the elements 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 sputtering,
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.

La Yu [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 Os
and Ce 2 O2, but they may be other than these.

Either one or both of Ce and La may be contained, but when both are contained, the quantitative ratio thereof is arbitrary.

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

In addition to rare earth element oxides, the solid protective layer 5 contains Si.
Contains.

Si 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, 0, and N.
When expressed as at%, 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 5 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. Furthermore, reactive sputtering may also be used.

Note that when containing La and/or Ce as rare earth elements, oxides of pyrophoric alloys such as alanyl metal, huber metal, Mitsch metal, Welsbach metal, etc. can also be used as at least a part of the sputtering target.

In addition, for the formation of the solid protective layer 5, other vapor phase film formation 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. When the thickness is less than the above range, the protective effect is insufficient, and when it exceeds the above range, spacing loss increases and recording density cannot be improved.

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" or less.
It is preferably 0" or less.

By setting the contact angle with water within such a range, the lubricating film 6 can be formed uniformly. 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 is 1
The temperature is approximately 8 to 23°C and 40 to 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, a thin film magnetic pole layer made of metal such as Co-Nb-Zr amorphous is formed on the above-mentioned ceramic substrate such as Al203-TiC, and a thin film magnetic pole layer made of metal such as Co-Nb-Zr amorphous is further formed.
20. It is preferable to use a material coated with an inorganic protective film such as .

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. A polishing liquid containing colloidal silica was used for mechanochemical polishing.

Glass substrates having different R max were produced by changing the polishing conditions. Table 1 shows the Rmax 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
Gas was introduced and reactive sputtering was performed to form a Fear 4 film. Note that the 02 gas was introduced so as to be blown onto the substrate.

P (
Ar+Osl and P (hl P (Ar+(hl) are shown in Table 1.

After forming the Fe504 film, 1
Oxidation was carried out for ~5 h and γ-
A Fezes magnetic layer was used. Note that the thickness of the magnetic layer is 2
000 people.

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

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

X-ray diffraction was performed on the magnetic layer of each sample to create an X-ray diffraction chart.

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. Further, the X-ray diffraction charts of samples No. 1 and 2 are shown in FIG. 5 and FIG. 6, respectively.

Furthermore, P(400)/P(311) and P(222)/ of the magnetic layer due to changes in PO□/PI^r+0□)
The changes in P(3113) are shown in FIG.

Then, on the magnetic layer of each sample: C+sHs, o 6 mol of H and C+iHs. C00CH2
A 10-4 mol/j2 chloroform solution with 4 mol 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 20 people is set up. layer to form a protective lubricating film.

Regarding the thus obtained magnetic disk samples, C8S durability was measured by the following method. The results are shown in Table 1.

CS Dandankyukami ■Magnetic head used (magnetic head No. 1) A 722 with Vickers hardness 2200 kgf/mm
After forming a thin film magnetic head element on a 0 s 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. The Rmax of the magnetic head flying surface was set to 130 people.

(Magnetic head No. 2) This magnetic head was manufactured in the same manner as magnetic head No. 31, except that a SiC substrate with a Vickers hardness of 3000 kgf/mm was used.

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

(2) C8S Using the above magnetic head, a C8S test was conducted at 25° C. and 50% relative humidity. C8S was carried out by repeating the cycle shown in FIG. C8S durability was determined by measuring the number of times until the recording and reproducing output decreased to less than half of the initial level, and was evaluated on the following five levels.

o: 100,000 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 × ×: 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)/P(311) within the range of the present invention, even when using a magnetic head with a high base hardness, C8
S Excellent durability.

[Example 2] Magnetic recording disk samples were prepared by changing the compounds contained in the protective lubricant film as shown in Table 2.

Sample No. prepared in Example 1 except for the protective lubricant film,
Same as 2. Also, the magnetic head is No. 1
It 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 10-4 mol/β chloroform solution of the compound shown in Table 2 was prepared and used as a developing solution.

First, an object to be treated 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 then the object to be treated is lowered and raised. This process was repeated to accumulate a monomolecular film, forming a protective lubricant film.

(Coating method) A chloroform solution of the compound shown in Table 2 was used as a coating solution. The concentration was 0.1 wt% for dipping and 0.2 wt% for spin code.

Side” L11 ■ L number Using the above magnetic head No. 1, 20°C, 6°% R
The coefficient of dynamic friction was measured at 1 rpm for 1 minute under H conditions.

The results are shown in Table 2.

,'-'7, Using the above magnetic head No. 1, 20"C16°%
After running in contact at 100 rpm for 30 minutes under RH conditions, the coefficient of dynamic friction was measured at 1 rpm for 1 minute.

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

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

From the results shown in Table 2, the effects of the present invention are clear.

[Example 3] In exactly the same manner as in Example 2, the performance of the lubricating film having the composition shown in Table 3 was evaluated.

However, friction coefficient measurement and durability running were conducted at 20°C and 80°C.
The condition was %RH.

The results are shown in Table 3.

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 Rmax shown in Table 4.

However, P (Ar4 (hl) and P ox/P (Ar4
(hl are I x 10-” Torr and 0.0 Torr, respectively.
It was set as 058.

Further, the oxidation after the formation of the Fe*Oa film was performed by heat treatment in the air under the conditions shown in Table 3 to obtain a γ-FeJs magnetic layer. The thickness of the magnetic layer was 2000.

Table 4 shows Rmax on the magnetic layer side of each magnetic disk sample.

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.

In addition, the X-ray diffraction chart of sample No. 32 was
As shown in the figure.

As shown in FIG. 9, this chart shows α-Fet
A peak with a surface index (104) of us was observed.

Further, the magnetic layer of this sample was analyzed using a low-incidence-angle X-ray diffraction apparatus 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)/P (311), which is about three times as large as a-F
It was confirmed that the content of ezOs was high on the surface side of the magnetic layer.

Incidentally, 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.

ffliiL Momme 5 ■ Magnetic head used A120s with Vickers hardness of 2200 kgf/mm2
- After forming a thin film magnetic head element on a TiC 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.

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

The slider width was 150 μm, 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 was pressed against the magnetic disk sample, and the relative speed between the magnetic disk and the magnetic head was 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 O: 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 C8s durability test. .

The reproduction output was measured for each sample shown in Table 3, and α-
The reduction in reproduction output due to the inclusion of FeJx was investigated.

Evaluation was made for sample No. 3, which does not contain α-F620a.
1 (1) The reproduction output was set to 100, and ○: 90 or more and ×: less than 90.

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

In addition, when a C8S 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 the same measurements as 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/mm2. Surface roughness (Rmax) 0.
015 μm polyimide was used.

[Soft magnetic film] D in an Ar atmosphere of 2×10-'Pa containing 2%0
80at%Ni-Fe by C magnetron sputtering method
The alloy was formed into a film having a thickness of 0.45 μm.

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

[Magnetic layer] 2 at% Cr-C by DC magnetron sputtering
It was formed by forming a film of o alloy to a thickness of 0.18 μm. 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 protective layer] 2%0. In an Ar atmosphere of lXl0-'Pa containing R
Solid protective layers having various compositions shown in Table 5 below were formed to a thickness of 0.01 μm by F magnetron sputtering. 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 μm 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 was 100 μm, the load was Log, and the relative speed between the needle and the sample was 10 mm/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 (rust) that appeared on the surface of the magnetic layer was measured.

(3) Measurement of electromagnetic conversion characteristics Using a main pole-excited single-pole thin film head with a magnetic pole thickness of 0.2 μm and a magnetic pole width of 50 μm, the relative speed between the head and the disk was 2.
Measure the f characteristic at m/sec, D. Evaluated by.

The thin film head consists of Co-N on Aρ103 TiC substrate.
A b-Zr amorphous magnetic pole and an A.degree. C. gos protective film formed by sputtering were used.

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

[Solid protective layer] In an atmosphere containing Ar, 0□ and/or N2,
A solid protective layer having various compositions and contact angles shown in Table 6 below was formed to a thickness of 0.01 mm by RF magnetron sputtering.
It was formed in μm.

In addition, the Ar pressure is 1X10-'Pa, and 1 to 10
The contact angle was changed by adding %02 and/or N. Note that among the samples shown in Table 6, those with contact angles exceeding 80° were formed by adding only 0□.

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 was used as the magnetic head, the load was Log, and 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/s, 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 results.

The results of these tests are shown in Table 6.

From the results shown in Table 6, 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 Table 7. The sample No. 52 prepared in Example 6 was the same except for the protective lubricant film.

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. A polishing liquid containing colloidal silica was used for mechanochemical polishing. 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.

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

The results are shown in Table 7.

・'-' 1. After indirect contact was performed for 30 minutes at 100 rpm in an atmosphere of 20° C. and 60% RH using the same magnetic head as above, the coefficient of dynamic friction was measured for 1 minute at 1 rpm.

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

[Example 8] In exactly the same manner as in Example 7, a magnetic disk having a protective lubricant film shown in Table 8 was produced.

These properties are shown in Table 8. Note that the friction coefficient measurement and durability running in Table 8 were performed in an atmosphere of 20° C. and 80% RH.

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 the X-ray diffraction apparatus. FIG. 3 is a schematic diagram of a low incidence angle X-ray diffraction device. FIG. 4 is a partial sectional view of a magnetic head used in the present invention. 5 and 6 are X-ray diffraction charts of the γ-Fe20a magnetic layer. Figure 7 shows the P(400)/P(311) and P(22
2) is a graph showing changes in P(311). FIG. 8 is a graph showing one cycle of C8S. FIG. 9 is an X-ray diffraction chart of the γ-Fears magnetic layer. FIG. 10 is an X-ray diffraction chart of the γ-Fe203 magnetic layer prepared for 5 seconds using a low incident angle X-ray diffraction device. 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 R3 ... Receiving slit MM ... Monochromator Sl, S2 ... Solar Slit Applicant: Representative of TDT-K Co., Ltd. Patent Attorney: Hikaru Ishii, Patent Attorney
Increase 1) Tatsuya FIG, 7 PO2/ P (Ar+02) (o/,) FIG, 8 8 Terama (male)

Claims (9)

[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 magnetic layer, characterized in that a protective lubricant film containing alcohol having a melting point of 30° C. or higher is provided on the magnetic layer and/or the magnetic head. A magnetic recording and reproducing method. (2) The magnetic recording and reproducing method according to claim 1, wherein the protective lubricant layer further contains an ester. (3) The magnetic layer according to claim 1 or 2, 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. Recording and playback method. (4) Claim 1 or 2, wherein the magnetic layer is a perpendicular magnetization film, and a solid protective layer is provided in contact with the perpendicular magnetization film.
The magnetic recording and reproducing method described in . (5) The ceramic substrate has a Vickers hardness of 10
5. The magnetic recording and reproducing method according to claim 1, wherein the magnetic head has a thin film pole layer on the ceramic substrate. (6) A continuous thin film magnetic layer containing γ-Fe_2O_3 as a 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 (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.
A magnetic recording medium characterized in that the surface roughness (Rmax) of the magnetic layer side surface is 50 to 200 Å, and a protective lubricant film containing alcohol having a melting point of 30° C. or higher is provided on the magnetic layer. (7) The magnetic recording medium according to claim 6, wherein the protective lubricant layer further contains ester. (8) A magnetic recording medium in which a soft magnetic film, a perpendicularly magnetized magnetic layer, 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 , represents one or more elements selected from rare earth elements including Y), O and N, and one or more elements selected from metals or semimetals excluding Against 1-1
A magnetic recording medium containing 0 at% R, wherein the protective lubricant film contains alcohol having a melting point of 30° C. or higher. (9) The magnetic recording medium according to claim 8, wherein the protective lubricant film further contains ester.