JPH0673177B2 - Magnetic storage body and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnetic storage body used for a magnetic storage device (a magnetic disk device and a magnetic drum device) and the like, and a manufacturing method thereof.

(Prior Art) Generally, there are roughly two types of recording / reproducing methods of a magnetic storage device, which mainly includes a recording / reproducing magnetic head (hereinafter referred to as a head) and a magnetic storage body, as follows. The first method is a method of making a space corresponding to an air layer between the head and the surface of the magnetic memory at the start of operation, and recording / reproducing in this state. In this method, the rotation of the magnetic storage body stops at the end of the operation, and at this time, the head and the surface of the magnetic storage body are in the contact friction state as at the start of the operation. The second method is to apply a required rotation to the magnetic memory in advance, and suddenly press the head against the surface of the magnetic memory to create a space corresponding to an air layer between the head and the magnetic memory. This is a method of storing and reproducing in the state. As described above, in the first method, the head and the magnetic memory surface are in a contact friction state at the start and end of the operation, and in the second method, the head is in a contact friction state when the head is pressed against the magnetic memory surface. The frictional force generated between the head and the magnetic memory body in these contact friction states may wear the head and the magnetic memory body, and eventually cause damage to the head and the metal magnetic thin film medium.

Further, in the contact state, a slight change in the posture of the head may make the load applied to the head non-uniform, and may scratch the head and the surface of the magnetic memory.

Further, the frictional force generated between the head and the magnetic memory in the contact friction state causes a large torque particularly when many heads are attached, and imposes an unfavorable burden on the motor for rotating the magnetic memory.

Further, during recording / reproduction, the head suddenly contacts the magnetic storage body, a large frictional force acts between the head and the magnetic storage body, and the head and the magnetic storage body are often destroyed.

In order to protect the head and the magnetic memory body from such contact frictional force between the head and the magnetic memory body, it is necessary to coat the surface of the magnetic memory body with a protective film. It is required to reduce the contact frictional force generated between the memory bodies (that is, reduce the frictional force).

Providing a lubricating layer on the surface of the magnetic memory is one method for reducing the contact frictional force. The lubricating layer must be well bonded to its substrate. If the lubrication layer is not sufficiently bonded to the substrate, it will be removed from the substrate due to contact friction between the head and the magnetic memory, or a large amount of lubricant will be generated around the head and between the head and the magnetic memory due to capillary action. In other words, the floating stability of the head during recording and reproduction is adversely affected.

The effect of reducing the contact frictional force between the lubricating layer and the head is achieved by interposing a non-polar molecular layer, which is unlikely to be adsorbed or adhered, at the interface between the head and the magnetic memory. That is, it is desirable that the lubricating layer be oriented in a portion that is coupled to the magnetic memory and a non-polar portion that is hard to adsorb to the head.

As such a lubricating layer, oils such as silicone oil, fluorine oil, fluorosilicone, silanes such as octadecyltrichlorosilane, hexamethyldisilazane, or silazanes have been proposed (Japanese Patent Publication No. 55-40932). Although these lubricating layers each have excellent characteristics, they do not have sufficient bonding force to chemically bond with amorphous inorganic oxides in oils, and they are adsorbed on the interface between the head and magnetic memory in silanes or silazanes. Or the molecular weight of the non-polar molecular layer, which is less likely to cause adhesion, is not sufficient. Therefore, there is a problem in that the effect of reducing the lubricant loss in the case of long-term use in oils and the effect of reducing the contact frictional force generated between the head and the magnetic memory in silane or silazane are not perfect.

An object of the present invention is to propose a magnetic memory body and a method for manufacturing the magnetic memory body which solve this problem.

(Means for Solving Problems) The gist of the present invention is that a substance having an alkoxysilyl group or a chlorosilyl group and an amino group is formed as a monomolecular layer on a magnetic memory body coated with an oxide film. ,
That is, a fluorinated carbon-based compound having a functional group that chemically bonds with an amino group is applied. That is, by using a monomolecular layer of a substance having an alkoxysilyl group or a chlorosilyl group and an amino group as a binder that firmly binds the oxide film and the fluorocarbon compound, and covering the surface of the base with a fluorinated compound, The surface energy on the body surface is sufficiently reduced to reduce the contact frictional force between the base body and the head. It is important to use a monomolecular film having an alkoxysilyl group or a chlorosilyl group as the binder and a fluorinated compound having a functional group that chemically bonds with the amino group.

(Function) As the amorphous inorganic oxide, it is preferable to use polysilicic acid or a sputtered film of SiO ₂ , glass, alumina or the like. The alkoxysilyl group or chlorosilyl group is highly reactive, and the silanol group (Si
-OH) and hydroxyl group (-OH) are chemically bonded to each other to form a monomolecular layer firmly bonded to the amorphous inorganic oxide. Since this monolayer has amino groups facing away from the substrate, it can form a chemical bond with a fluorinated compound having a carboxyl group or an acid chloride, so that the amorphous inorganic oxide and the fluorinated compound are strongly bonded to each other. Can act as a binder to bind to. On the other hand, fluorine or a compound lowers the surface energy and shows an excellent lubricating effect. Therefore, the general formula Or (Wherein at least one of X, Y and Z is an alkoxy group or chlorine and the other is an alkyl group), a monolayer of a substance and a fluorinated compound having at least one carboxyl group or acid chloride in the molecule are used. For example, an excellent lubricant that is firmly bonded to the base material can be obtained. As the fluorinated compound, any compound containing fluorine can be used, but considering the performance as a lubricant, it has 10 carbon atoms.
Fluorine-substituted products of long-chain hydrocarbons of up to 20 are preferable.

Although the adhesiveness between the base material and the polymer is still excellent as it is, the surface can be completely cleaned by forming the polymer film after treating it in plasma after forming the amorphous inorganic oxide. In addition, because of the fact that radicals that interact with the polymer are generated by the implantation of ions, the adhesion between the base and the lubricant is further improved.

Further, for recording and reproduction, it is advantageous that the spacing (the distance between the head and the magnetic memory at the time of recording and reproduction) is small. Therefore, it is desirable that the thickness of the lubricating layer is as thin as possible, but the monomolecular film and the fluorinated compound can form a very thin lubricating layer. After forming a monomolecular layer on an amorphous inorganic oxide and applying a fluorinated compound, a chemical reaction is caused to combine the monomolecular film and the compound, and then combined with the monomolecular layer by Freon cleaning. The excess lubricant not applied is removed, forming a very thin lubricating layer. The chemical reaction with the monolayer proceeds naturally after application, but it takes only a short time if baked.

(Example 1) Hereinafter, the present invention will be described in detail with reference to Examples. FIG. 1 is a sectional view showing the structure of the magnetic memory body of the present invention.
In the drawing, in the magnetic memory according to the present invention, a non-magnetic alloy layer 2 is coated on an alloy disk 1, and a metal magnetic thin film medium 3 is coated on the polishing surface of this coating. The oxide 4 is coated, and the lubricant 5 is further coated thereon.

Nickel-phosphorus as the non-magnetic alloy layer 2 on the disk-shaped aluminum alloy substrate finished on the surface having a sufficiently small waviness (50 μm or less in both the circumferential direction and the radial direction) by lathe processing and heat correction as the alloy disk 1 Ni-
P) An alloy is baked and plated to a thickness of 50 μm, and the Ni-P plated film is mechanically polished to a mirror finish to a surface roughness of 0.04 μm or less and a thickness of about 30 μm, and a metal magnetic thin film medium 3 is formed thereon. Cobalt-Nickel-Phosphorus (Co-Ni-P)
The alloy was plated to a thickness of about 0.05 μm. Furthermore, this Co-
A solution having the composition shown below was thoroughly mixed on the Ni-P alloy film, dust or deposited SiO ₂ was removed through a 0.5 μm filter film, and then applied by spin coating.

Tetrahydroxysilane 11% Ethyl alcohol solution: 20% by weight n-Butyl alcohol: 80% by weight After that, the disc substrate was baked at a temperature of 200 ° C. for 3 hours C
A polysilicic acid film was formed on the o-Ni-P alloy film.

This substrate is treated with 3-aminopropyritrimethoxysilane [H ₂
N (CH ₂ ) ₃ Si (OCH ₃ ) ₃ ] was held at room temperature for 30 minutes and then baked at 100 ° C. for 30 minutes to form a monomolecular film. A 5% by weight solution of nonadecafluorodecanoic acid in toluene was filtered through a 0.2 μm filter.
This solution was dropped onto the disk substrate on which a monolayer of 3-aminopropyltrimethosisilane was formed, baked at 100 ° C for 40 minutes, and then washed with Freon to remove unreacted nonadecafluoro. The decanoic acid was washed off.

If the surface energy of the substrate before and after the surface of applying a fluorinated compound by measuring the contact angle of droplets with different surface tension is calculated by the following polymer coating from 43erg / cm ² on the polysilicic acid coating and 15erg / cm ² It was found that the surface energy was remarkably lowered and the effect of preventing the adhesion between the head and the base body was great.

Next, the coefficient of dynamic friction acting between the disk base and the head was measured. The dynamic friction coefficient was determined by connecting a strain gauge to the head, measuring the dynamic friction force between the head and the disk generated when the disk was rotated at a constant speed, and dividing this by the load applied to the head. Measurement is load 15g, sliding speed 1
It was performed under the condition of 00 mm / min. As a result, 0.171 was obtained as the value of the dynamic friction coefficient, which was 0.546 when the lubricating layer was not formed.
It was possible to reduce the value of the dynamic friction coefficient as compared with.

In addition, the contact friction test between the disk and the head was repeated 30,000 times using a disk base on which this lubricating layer was formed and a monolithic head with a load of 70 g, but there was no change in the surface condition of the disk due to head crash or contact friction by the head. Met.

(Example 2) A disk substrate prepared in the same manner as in Example 1 and having a polysilicic acid film formed thereon was held in vapor of 3-aminopropyltrimethoxysilane for 30 minutes and then baked at a temperature of 100 ° C for 30 minutes. A monolayer was formed. A 1% by weight toluene solution of nonadecafluorodecainoic acid chloride synthesized from thionyl chloride as a catalyst from nonadecafluorodecanoic acid was prepared and filtered through a 0.2 μm filter. This fluorinated compound was dropped on the disk substrate on which a monomolecular layer of 3-aminopropyltrimethoxysilane was formed, and the mixture was baked at a temperature of 100 ° C. for 40 minutes, and then unreacted nonadacafluorodecanoic acid chloride was removed with Freon. I washed it off. The values of the surface energy and the dynamic friction coefficient were obtained by the same method as in Example 1. As a result, the value of surface energy by applying a fluorinated compound is reduced from 43erg / cm ² on the polysilicic acid coating 17erg / cm ^2, the value of the dynamic friction coefficient was able to 0.187 smaller from 0.546.

Further, the abrasion resistance was evaluated in the same manner as in Example 1, but there was no change in the surface condition of the disk due to the contact friction test of 30,000 times.

(Example 3) Co-Ni of a disk substrate prepared by the same method as in Example 1
Instead of the polysilicic acid coating, Al ₂ O ₃ (amorphous alumina) was coated on the -P alloy film by the sputtering method. This disk substrate was baked in vapor of 3-aminopropyltrimethoxysilane at room temperature for 1 hour to form a monomolecular layer. Example 1
Add the fluorinated compound solution prepared in step 4.
After baking for 0 minutes, the unreacted fluorinated compound was washed off with Freon, and the surface energy was measured in the same manner as in Example 1.
The value of the dynamic friction coefficient was obtained. As a result, the surface energy is 45 erg / cm ² on amorphous alumina to 1 on fluorinated compounds.
It was reduced to 5 erg / cm ² and the value of the dynamic friction coefficient could be reduced from 0.270 to 0.175.

Further, the abrasion resistance was evaluated in the same manner as in Example 1, but there was no change in the surface condition of the disk due to the contact friction test of 30,000 times.

(Example 4) In the same manner as in Example 1, 3-aminopropyltrimethoxysilane was replaced with 3-aminopropyltriethoxysilane [NH ₂
Instead of (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃ ], the experiment was conducted under exactly the same other conditions. As a result, the surface energy value is reduced from 43erg / cm ² on the polysilicic acid to 15erg / cm ² on the polymer, after the fluorinated compound applied as the value of the dynamic friction coefficient 0.17
5 was obtained and could be made smaller than 0.546 on the polysilicic acid film.

Further, the abrasion resistance was evaluated in the same manner as in Example 1, but there was no change in the surface condition of the disk due to the contact friction test of 30,000 times.

(Example 5) In the same manner as in Example 1, 3-aminopropyltrimethoxysilane was replaced with 3-aminopropyltrichlorosilane [NH ₂ (C
H ₂ ) ₃ SiCl ₃ ], and other conditions were exactly the same. As a result, the surface energy value on polysilicic acid
Decreased from 43erg / cm ² to 14erg / cm ² on the polymer, 0.170 is obtained after fluorinated compounds applied as a value of dynamic friction coefficient,
It can be made smaller than 0.546 on the polysilicic acid film.

Further, the abrasion resistance was evaluated in the same manner as in Example 1, but there was no change in the surface condition of the disk due to the contact friction test of 30,000 times.

(Example 6) In the same manner as in Example 1, 3-aminopropyltrimethoxysilane was replaced with p-aminophenyltrimethoxysilane. Instead, the experiment was conducted under the same conditions other than the above. As a result, the surface energy value is 43 erg / cm ² on polysilicic acid.
To 16 erg / cm ² on the fluorinated compound, the coefficient of kinetic friction was 0.181 after coating the polymer, which was smaller than 0.546 on the polysilicic acid film.

Further, the abrasion resistance was evaluated in the same manner as in Example 1, but there was no change in the surface condition of the disk due to the contact friction test of 30,000 times.

(Example 7) Example 1 In the same manner as 3-aminopropyltrimethoxysilane 3-aminopropylmethyldiethoxysilane _{[NH 2 (CH 2) 3} Si (OC 2 H 5) 2 CH 3] Nikae, The experiment was conducted under the same conditions except that the substrate was kept in the vapor of this compound for 1 hour at room temperature. As a result, the value of the surface energy decreases from 43erg / cm ² on the polysilicic acid to 18erg / cm ² on the polymer, fluorinated compounds after coating 0.190 is obtained as the value of dynamic friction coefficient, on polysilicic acid coating 0.546
I was able to make it smaller than.

Further, the abrasion resistance was evaluated in the same manner as in Example 1, but there was no change in the surface condition of the disk due to the contact friction test of 30,000 times.

Example 8 A disk substrate prepared in the same manner as in Example 1 and having a polysilicic acid film formed thereon was placed in a parallel plate type etching apparatus,
Flow rate 18sccm, power density 0.35w / cm ² , pressure 1.3 using Ar
After etching for 2 minutes under the conditions of Pa and a bias potential of 1 KV, as in Example 1, holding in vapor of 3-aminopropyltrimethoxysilane for 30 minutes, the temperature was 100 ° C. for 30 minutes.
It was baked for a minute to form a monomolecular layer. The fluorinated compound solution prepared in Example 1 was dropped onto this disk substrate, and the temperature was raised to 100 ° C.
After baking for 40 minutes, the excess fluorinated compound was washed off with Freon, and the surface energy was measured in the same manner as in Example 1.
The value of the dynamic friction coefficient was obtained. As a result, the surface energy value was 50 erg / g on the polysilicic acid film after Ar plasma treatment.
Further drops than without the 14erg / cm ² and Ar plasma treatment on the fluorinated compounds from cm ^2, the value of the dynamic friction coefficient could be reduced to 0.101 after lubricating layer formed from 0.614 on polysilicic acid.

The polysilicic acid coating prepared in Example 1 is not sufficiently reduced in surface energy and dynamic friction coefficient even if the same treatment as in Example 1 is carried out if it is left for a long time after formation, but if it is treated with Ar plasma, it will take a long time. The same result was obtained, and it was found that the surface modification by Ar plasma treatment was effective.

Further, as in Example 1, there was no change in the disk surface state due to the contact friction test of 30,000 times.

Example 9 A disk substrate prepared by the same method as in Example 3 and coated with amorphous alumina was treated with Ar plasma under the same conditions as in Example 8. After that, the substrate was kept in vapor of 3-aminopropyltrimethoxysilane at room temperature for 30 minutes and then baked at 100 ° C. for 30 minutes to form a monomolecular layer. The fluorinated compound solution prepared in Example 2 was added dropwise.
After baking at a temperature of 100 ° C. for 40 minutes, excess polymer was washed off with Freon. The values of the surface energy and the dynamic friction coefficient were obtained by the same method as in Example 1. As a result, the surface energy value was 52 erg / cm on alumina treated with Ar plasma.
It was possible to reduce the value from ² to 0.177 after dropping the fluorinated compound.

Further, as in Example 1, there was no change in the surface condition of the disk due to the contact friction test of 30,000 times.

(Example 10) In the same manner as in Example 8, only 3-aminopropyltrimethoxysilane was replaced with 3-aminopropylmethyldiethoxysilane, and the other conditions were exactly the same. As a result, the value of surface energy is 50erg /
It drops from cm ² to 11Erg / cm ² on the polymer, 0.171 after fluorinated compound coating is obtained as the value of dynamic friction coefficient, compared to 0.546 on polysilicic acid coating, could be reduced.

Further, the abrasion resistance was evaluated in the same manner as in Example 1, but there was no change in the surface condition of the disk due to the contact friction test of 30,000 times.

(Example 11) In the same manner as in Example 1, only nonadecafluorodecanoic acid was replaced with pentadecafluorooctanoic acid, and other conditions were the same as in Example 1 for the experiment. As a result, the value of surface energy is
It decreased from 43erg / cm ² to 18erg / cm ² on the polymer, fluorinated compounds after coating 0.190 is obtained as the value of dynamic friction coefficient, compared to 0.546 on polysilicic acid coating, could be reduced.

Further, the abrasion resistance was evaluated in the same manner as in Example 1, but there was no change in the surface condition of the disk due to the contact friction test of 30,000 times.

(Effects of the Invention) As described above, the magnetic storage device according to the present invention has a great effect of reducing the contact frictional force generated between the head and the magnetic storage device, and is expected to be applied to magnetic disk devices, magnetic drum devices, and the like. Is.

[Brief description of drawings]

FIG. 1 is a view showing a cross section of a magnetic memory body of the present invention. In the figure, 1 is an alloy disk, 2 is a mirror-finished non-magnetic alloy layer, 3 is a metal magnetic thin film medium, 4 is an amorphous inorganic oxide, 5 is an oriented lubricant layer, and 6 is a protective film. It is composed of a crystalline inorganic oxide 4 and an oriented lubricating layer 5. The orientation lubricating layer 5 is composed of a monomolecular layer and a polymer coating film.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Alan Kent Engel 4-28-14-709, Asagaya Kita, Suginami-ku, Tokyo Asaya Corpora (56) References JP-A-54-45103 (JP, A) JP-A-SHO 62-145532 (JP, A) JP-A-54-40606 (JP, A)

Claims (3)

[Claims] 1. A metal magnetic thin film medium is coated on an alloy disc coated with a mirror-polished non-magnetic alloy layer or on a mirror-polished alloy disc, and an amorphous inorganic oxide layer is formed on the medium. In the magnetic memory, which is coated and further coated with an orientational lubricant capable of sticking to the amorphous inorganic oxide layer, the orientational lubricant is represented by the general formula: Or (At least one of X, Y and Z is an alkoxy group or chlorine, and the other is an alkyl group), and a fluorinated carbon-based compound containing a monomolecular layer of a substance and at least one carboxy group or acid chloride in the molecule. A magnetic memory comprising a reaction product with. 2. A metal magnetic thin film medium is coated on an alloy disc coated with a mirror-polished non-magnetic alloy layer or on a mirror-polished alloy disc, and an amorphous inorganic oxide layer is coated thereon. Further, on the above amorphous inorganic oxide, the general formula Or (At least one of X, Y, and Z is an alkoxy group or chlorine, and the other is an alkyl group) is vapor-deposited, and then at least one carboxyl group or acid chloride is contained in the molecule. A method of manufacturing a magnetic memory body, characterized in that the fluorinated carbon-based compound containing is applied or baked after applying to bond the amorphous inorganic oxide layer and the compound. 3. An alloy disc coated with a mirror-polished non-magnetic alloy layer or a mirror-polished alloy disc is coated with a metal magnetic thin film medium, and an amorphous inorganic oxide layer is coated thereon. Treated in plasma, on the amorphous inorganic oxide layer, the general formula Or (At least one of X, Y, and Z is an alkoxy group or chlorine, and the other is an alkyl group) is vapor-deposited, and then at least one carboxyl group or acid chloride is contained in the molecule. A method of manufacturing a magnetic memory body, characterized in that the fluorinated carbon-based compound containing is applied or baked after applying to bond the amorphous inorganic oxide layer and the compound.