JP2598960B2 - Glassy carbon composite material, method for producing the same, and sliding contact part - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a composite material having high wear resistance and low coefficient of friction. In particular, the present invention relates to a glassy carbon composite material and a method for producing the same, a sliding part, a mechanical device, and a magnetic recording device using the glassy carbon composite material.

〔Overview〕

The present invention provides a glassy carbon composite material having high wear resistance and a small wear coefficient by mixing specific ultrafine particles as a reinforcing component in a composite material mainly containing glassy carbon and a method for producing the same. Things.

Further, the present invention provides a sliding contact part, a mechanical device, and a magnetic recording device using the glassy carbon composite material.

[Conventional technology]

At present, various devices for performing recording and reproduction using a sheet or film having a magnetic layer or paper as a recording medium are commercially available. These recording / reproducing devices include a large number of components that constantly or temporarily slide in contact with a recording medium. Such components include a head slider of a flexible disk, a flying slider of a hard disk, a thermal paper print head, a magnetic head, and the like. These components are required to have excellent durability and not to damage a recording medium which is in sliding contact with the components. Also,
These parts, especially magnetic heads, require ultra-precision machining of several microns to several tens of microns, and require precise machining characteristics of the material.

As materials for such components, silicon dioxide, alumina, silicon carbide, hard glass, alumina-based ceramics, ferrite, calcium titanate, barium titanate, and the like are generally used. However, these materials are suitable for precision parts, but have high hardness and poor slidability with the recording medium, and thus may damage the recording medium.

A graphite material is known as a material having extremely good slidability, but has a high abrasion property, and it is difficult to maintain a stable shape over a long period of time. In addition, sufficient densities cannot be obtained due to the constituent particles, and thus they are not suitable for use as precision parts.

Therefore, the present applicant has conducted various studies in order to solve the above-mentioned drawbacks, and has found that glassy carbon can solve the above-mentioned drawbacks, and has previously filed an application. These applications are disclosed in JP-A-59-84.
No. 325, and Japanese Patent Application Laid-Open No. 59-144019.

Glassy carbon is a material with moderate lubricity,
When sliding with a mating material, the glassy carbon itself has a property of being worn first before the mating material is damaged.

Further, the present applicant has previously filed an application for a glassy carbon having particularly excellent wear properties and a method for producing a composite material using the glassy carbon as a matrix. Regarding the production method of glassy carbon, JP-A-59-169915, JP-A-60-131816, JP-A-60-171208, JP-A-60-171209, JP-A-60-171209 No. 171210, JP
It is published as Japanese Patent Application No. 60-171211.

[Problems to be solved by the invention]

However, as a result of further tests, it was found that the known glassy carbon material sometimes had insufficient wear resistance due to the roughness and hardness of the surface of the mating material.

The present invention provides a low frictional resistance with a mating material without applying a lubricant to the surface of the mating material to be in sliding contact and without providing a protective film on the surface of the mating material. It is an object of the present invention to provide a sliding contact part having excellent wear resistance and durability, a material capable of producing the same, and a method for producing the same.

[Means for solving the problem]

A first aspect of the present invention is a glassy carbon composite material, having glassy carbon as a main component and a reinforcing component,
It is characterized by containing at least one of α-alumina ultrafine particles and titanium compound ultrafine particles composed of titanium carbide TiC and titanium oxide TiO _x . Where x = 1
~ 2.

It is desirable that the surface of the α-alumina ultrafine particles and / or the titanium compound ultrafine particles is coated with silicon carbide SiC and / or silicon oxide SiO ₂ .

By coating the surface of the ultrafine particles by silicon carbide SiC and or silicon oxide SiO _2, the silicon compound at the interface between the carbon matrix and ultrafine filler is interposed. Thereby, the bonding strength between the filler and the matrix can be improved, the filler can be prevented from being lost during sliding, and the wear resistance can be improved.

Alumina has higher hardness in α-type than in γ-type crystals,
The wear resistance can be further improved.

The value of x in the compositional ratio and titanium oxide TiO _x of the two components of the titanium compound fine particles, the particle size of the titanium oxide to be mixed before firing, the amount of the added silane coupling down coupling agent, the firing temperature and firing It changes depending on the atmosphere inside. In the present invention, the molar ratio between titanium carbide TiC and titanium oxide TiO _x is TiO / TiO _x = 0.01 to 100, and x = 1 to 2.

Here, the ultrafine particles are particles having a particle diameter of 1 μm or less, preferably particles having a particle diameter of 0.1 μm or less. Methods for producing these ultrafine particles include gas-evaporation methods, plasma evaporation methods, and gas-phase chemical reaction methods using a gas-phase reaction, and precipitation methods, melt-spray pyrolysis methods using a liquid-phase reaction. The law is known. The present invention does not make the manufacturing method a problem.

Although the particle size of the ultrafine particles varies depending on the use of the glassy carbon composite material, the particle size is determined so as not to impair the homogeneity of the glassy carbon, and to mix and disperse with the precursor before curing, homogeneity and stability. Ultra fine particles of 0.1 μm or less are desirable.

Examples of such ultrafine particles include ultrafine aluminum oxide particles (alumina oxide C, particle size of about 0.02 μm, δ-alumina) manufactured by Nippon Aerosil Co., Ltd. converted into α-alumina by flash firing method (particle size). About 0.09 μm), ultrafine particles of titanium oxide (particle size: 0.01 to 0.03 μm, anatase) manufactured by Sumitomo Cement Co., Ltd. and others can be used.

The content of the ultrafine particles is desirably in the range of 0.005 to 0.2 in volume ratio to glassy carbon, and more preferably 0.005 to 0.1.
Is desirable. In this range, precision workability,
Excellent in wear resistance and coefficient of friction. When the content of the ultrafine particles is small, the effect of mixing cannot be obtained. On the other hand, if the amount is too large, the precision workability decreases, and the friction coefficient increases.

The glassy carbon which is a main component of the glassy carbon composite material of the present invention is a glassy carbon obtained by carbonizing a thermosetting resin such as a furan resin or a phenolic resin, or a glassy carbon obtained by carbonizing a phenolic resin. Glassy carbon or the like obtained by carbonizing a resin modified by polymerization or co-condensation is used.

In particular, nonporous glassy carbon obtained from a thermosetting resin which can contain 20% or more of water in the state of an initial condensate, that is, JP-A-60-171208, JP-A-60-17
No. 1209, JP-A-60-171210 or JP-A-60-171
It is desirable to use the glassy carbon disclosed in Japanese Patent No. 171211.

These glassy carbons are materials in an amorphous state, have moderate lubricity, and when the recording medium slides,
It is a material that wears itself before the surface film of the recording medium is damaged.

A second aspect of the present invention is a method for producing the above-mentioned glassy carbon composite material. That is, a glass comprising a curing step of mixing and curing ultrafine particles having an average particle diameter of 1 μm or less with a curing precursor of a thermosetting resin, and a carbonizing step of heating and carbonizing the resin obtained in the curing step. In the method for producing a fibrous carbon composite material, α
Using alumina ultra-fine particles and / or titanium oxide ultra-fine particles, as a carbonization step, a pre-treatment step of heat treatment at 800 to 1200 ° C., and after this step, applying a pressure of 1000 atm or more in an inert atmosphere at 1200 to 1700 ° C. And a pressure heat treatment step of heat treatment.

In this case, it is desirable to include a step of subjecting the α-alumina ultrafine particles and / or titanium oxide ultrafine particles to a surface treatment with a silane coupling agent.

In addition, the step of surface treating the silane coupling agent,
It can also be used when using silicon carbide SiC as ultrafine particles.

That is, the third aspect of the present invention is a curing step of mixing and curing silicon carbide ultrafine particles having an average particle diameter of 1 μm or less with a curing precursor of a thermosetting resin, and heating the resin obtained by the curing step. And a carbonizing step of carbonizing, comprising the step of surface treating silicon carbide ultrafine particles with a silane coupling agent, the carbonizing step is a pretreatment step of heat treatment at 800 to 1200 ° C. And a pressure heat treatment step of performing a heat treatment at 1200 to 1700 ° C. while applying a pressure of 1000 atm or more in an inert atmosphere after this step.

The crystal form of the silicon carbide ultrafine particles may be α-type or β-type. Examples of such ultrafine particles include silicon carbide ultrafine particles (having a particle size of about 0.06 μm, α-Si
C) can be used.

By treating the ultrafine particles with a silane coupling agent, the ultrafine particles can be prevented from condensing when mixed and dispersed in a liquid curing precursor, and the homogeneity and stability of the dispersion can be improved. it can. Further, the silane coupling agent is thermally decomposed in the firing step, and one or both of silicon carbide SiC and silicon oxide SiO ₂ can be formed at the interface between the matrix and the filler.

Here, the silane coupling agent is n = 2 or 3, R: methyl group or ethyl group, X: organic reactive group capable of binding to organic resin, vinyl,
It is a compound represented by, including amino, epoxy, methacryl, mercapto and others. Particularly desirable among such compounds are silane coupling agents having an amino or epoxy as an organic reactive group.

As the treatment with the silane coupling agent, the ultrafine particles may be directly processed, or may be added to a mixture of a thermosetting resin and an ultrafine particle filler.

The addition amount of the silane coupling agent is 0.2 to 3% by weight based on the thermosetting resin.

In order to apply pressure in the heat treatment step, a method of applying pressure directly or indirectly to the material being processed by applying a hydraulic pressure or other mechanical force from the outside to the sealed container is used. By this method, the pressure of the gas in the closed container is reduced.
The pressure can be increased to 1000 atmospheres or more, and the pressure of this gas can be used to apply an isotropic pressure to the sample inside. As this method, HIP (hot isostatic pressing) treatment is particularly preferred. HIP processing is a processing method in which the pressure of an inert gas is applied to an object to be processed at a high temperature.

By performing the pressure heat treatment step, it is possible to prevent the generation of voids during firing, to reduce the fine pores present in the glassy carbon, and to manufacture a dense glassy carbon composite material, And / or silicon oxide can be interposed to increase the bonding strength between the filler and the matrix. Thereby, wear resistance can be improved.

The temperature in the pretreatment step needs to be 800 ° C. to 1200 ° C., but is preferably 1000 ° C. to 1200 ° C.
If it exceeds 1200 ° C., the effect of the subsequent pressure heat treatment step cannot be obtained. Also, when the temperature is 800 ° C. or lower, the desired effect cannot be obtained in the pressure heat treatment step.

The temperature in the pressure heat treatment process is 1200 ℃ ~ 1700 ℃
Is required, and it is desirable that the temperature be 1400 ° C. or higher. 1700
If the temperature exceeds ℃, the matrix receives stress concentration on the filler surface, and the carbon around the filler is graphitized. In this case, the obtained glass-like carbon composite material has large abrasion due to delamination. Experiments have shown that when pressurized to a pressure of at least 1000 atm and baked at a temperature of at least 1700 ° C., wear is significantly increased. At this time,
When a wide-angle X-ray diffraction profile by Cu-Kα ray was examined, the appearance of a _d002 peak of graphite near 2θ = 26.4 ° was confirmed. With the appearance and growth of the graphite peak, the wear resistance was greatly degraded. From this, it was found that a treatment at a final temperature exceeding 1700 ° C. should not be performed.

A good effect can be obtained when the pressure in the pressure heat treatment step is 1000 atm or more, particularly 1500 atm or more, regardless of the type of the resin material.

The glassy carbon composite material of the present invention is a dense material in which inorganic ultrafine particles are uniformly dispersed in glassy carbon, and a filler and a matrix are strongly bonded to each other through silicon carbide and / or silicon oxide. For this reason, the wear resistance is further improved while maintaining the low friction coefficient of glassy carbon. Therefore, using this material, it is possible to manufacture a sliding contact part having a small friction resistance with the counterpart material, not damaging the counterpart material, and having excellent wear resistance and durability.

That is, a fourth aspect of the present invention is a sliding part using the above-mentioned glassy carbon composite material. That is, in a sliding contact part provided on a movable part of a mechanical element and sliding relatively temporarily or constantly in contact, at least the sliding contact surface is formed of the above-mentioned glassy carbon composite material. I do. Such sliding parts are
Available for general machinery and equipment.

The mating material of the sliding contact part differs depending on its use. For example, when the sliding parts are used for a magnetic head, a floppy disk head slider, or a hard disk flying slider, the mating material is a floppy disk, a hard disk, a magnetic tape, or the like. The material is paper or a polymer sheet, and is steel such as SUJ2 when used as a ball retainer for a bearing. As described above, the mating member may have any shape such as a flat surface, a curved surface, or a thread shape, and may have a shape that is not deformed or may be flexible.

Furthermore, it can be used for rings for high-speed twisting, blades for vane pumps, various bobbins and guides.

In particular, when this material is used for a sliding contact part with a recording medium, no lubricant is used between the recording medium and the lubricating property can be maintained for a long time, and the surface of the recording medium is damaged. In addition, there is an advantage that the wear of the material itself is small.

In addition, static electricity is not generated due to the conductivity of the glassy carbon, and there is an effect that dust hardly adheres to a portion in contact with the disk recording medium and the recording medium itself.

In other words, this sliding contact component can be used as a component that slides relatively or temporarily on a recording medium while temporarily or constantly in contact with the recording medium, and can be used for a magnetic recording apparatus.

The magnetic recording device according to the present invention includes a device for reproducing and / or recording information by using a magnetic recording medium such as a disk drive and a tape drive, and a case for accommodating the magnetic recording medium and other peripheral devices.

The sliding parts include a head and a head slider of a magnetic disk device, that is, a bulk head, a thin film head, other recording / reproducing elements, and a support thereof, and the shape of the spherical surface or the like does not matter. It also includes stabilizers, pads, regulating plates, and other stabilizing plates called by names, that is, those that mainly provide a relatively stable space between the medium and the head. Also includes a liner in the jacket. In the case of a magnetic tape device, not only the head and head slider, but also a cylinder that supports the head, guide pins and guide rollers that regulate the running of the tape, and a friction sheet that controls the winding characteristics and running properties of the tape in the tape cassette. , Guide pins and others. It also includes a floating head of a hard disk and a head slider. Further, it includes a part that may temporarily or always be in direct sliding contact with the magnetic recording medium and a part that comes into contact with the magnetic recording medium, such as a part where the multi-track head substrate directly contacts the medium.

By using the glassy carbon composite material of the present invention for such a sliding contact part, the sliding contact property with the medium is improved,
The frictional resistance is small, and the recording / reproducing characteristics can be provided for a long time without damaging the medium.

(Operation)

The vitreous carbon composite material of the present invention is a material in which inorganic ultrafine particles are dispersed in vitreous carbon to improve the abrasion resistance while maintaining the low friction property of vitreous carbon. Therefore, by using this composite material, it is possible to manufacture a sliding contact part having low friction resistance with a mating material, not damaging the mating material, and having excellent wear resistance and durability.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to the present invention. However, the following examples are merely examples, and do not limit the technical scope of the present invention. Further, “parts” in the examples all indicate “parts by weight”.

The particle size of ultrafine particles can be determined by microscopy, Coulter counter, centrifugal sedimentation, electromagnetic wave scattering, specific surface area measurement, etc., but the values shown below were measured by a scanning electron microscope (SEM). Things.

In addition, the particle size and dispersion state of the ultrafine particles in the glassy carbon composite material were analyzed using a scanning electron microscope image and an X-ray microanalyzer (EPMA) image. The crystal form of each ultrafine particle was analyzed with an X-ray diffractometer.

The silicon oxide SiC or silicon oxide SiO _{2 at} the interface between the filler and the glassy carbon matrix was observed by a transmission electron microscope (TEM) image and analyzed by selected area electron diffraction (SAD).

Example 1 500 parts of furfuryl alcohol and 480 parts of 92% paraformaldehyde were stirred and dissolved at 80 ° C., and a mixture of 520 parts of phenol, 8.8 parts of sodium hydroxide and 45 parts of water was added dropwise with stirring. After completion of the dropwise addition, the reaction was carried out at 80 ° C. for 3 hours.
Thereafter, a mixture of 80 parts of phenol, 8.8 parts of sodium hydroxide and 45 parts of water was further added, and the mixture was reacted at 80 ° C. for 4.5 hours. After cooling to 30 ° C., it was neutralized with 70% paratoluenesulfonic acid. The neutralized product is dehydrated under reduced pressure to 15
0 parts of water were removed and 500 parts of furfuryl alcohol were added. The viscosity of the obtained resin was 680 cps at 25 ° C. The amount of water that this resin could contain was 38%.

Ultrafine particles obtained by converting delta-alumina ultrafine particles (aluminum oxide C manufactured by Nippon Aerosil Co., Ltd.) having an average primary particle diameter of about 0.02 μm into α-alumina by a flash firing method are added to the thermosetting resin precondensate. (A particle size of about 0.09 μm) was added at a ratio of 2% by weight and dispersed and mixed with a sand mill.

This was poured into a 5 mm-thick strip-shaped mold and degassed under reduced pressure. Next, it heated at 50-60 degreeC for 3 hours, and also 90 degreeC for 5 days. The strip-shaped material thus obtained is placed in a tube furnace, and heated in a nitrogen atmosphere at a rate of 2 to 5 ° C./hour.
It was heated to 1200 ° C., kept at this temperature for 2 hours and cooled.

Next, this material was inserted into a sample chamber of a HIP device (hot isostatic pressing device), pressurized and treated at 1400 ° C. and 2000 atm for 2 hours.

When the obtained sample was measured by X-ray diffraction, α-
It was a composite of alumina and glassy carbon. The density and bending strength of this sample were 1.65 g / c ³ and 1240 g, respectively.
kg / cm ² .

(Example 2) The thermosetting resin precondensate obtained in Example 1 was added with an average particle size.
0.06 μm silicon carbide ultrafine particles (manufactured by Hakusui Chemical Co., Ltd.
α-SiC) was added at 2% by weight. Further, 1.0% by weight of a silane coupling agent (3-glycidoxypropyltrimethoxysilane) was added to the thermosetting resin initial condensate, and the mixture was dispersed and mixed with a sand mill. Thereafter, it was baked at 1200 ° C. in the same manner as in Example 1, and treated at 1400 ° C. and 2000 atm with a HIP apparatus.

When the obtained sample was measured by X-ray diffraction, it was a composite of α-type silicon carbide and glassy carbon. The density and flexural strength of these samples were 1.70 g / cm respectively.
³ , 1300 kg / cm ² .

(Example 3) Ultra-fine particles of delta alumina having an average primary particle size of about 0.02 µm (aluminum oxide C manufactured by Nippon Aerosil Co., Ltd.) were flash-fired with the thermosetting resin precondensate obtained in Example 1 Ultra-fine particles (particle size: about 0.09 μm) converted to α-alumina by 2% by weight, and further, 0.2% by weight of 3-glycidoxypropyltrimethoxysilane is added to the thermosetting resin. And dispersed and mixed.

This sample was fired at 1200 ° C. in the same manner as in Example 1, and the obtained fired product was inserted into the sample chamber of the HIP device and treated at 1400 ° C. and 2000 atm for 2 hours.

When the obtained sample was measured by X-ray diffraction, α-
It was a composite of alumina and glassy carbon. The density and bending strength of this sample were 1.65 g / cm ³ and 126, respectively.
It was 0 kg / cm ² .

(Example 4) 5% by weight of ultrafine titanium oxide particles (anatase type titania, manufactured by Sumitomo Cement Co., Ltd.) having an average primary particle size of 0.02 μm was added to the thermosetting resin precondensate obtained in Example 1. At the rate of Furthermore, 0.3% of 3-glycidoxypropyltrimethoxysilane was added to the thermosetting resin and dispersed and mixed by a sand mill. Thereafter, similarly to the first embodiment,
It was baked at 1200 ° C., and treated at 1400 ° C. and 2000 atm with a HIP device.

When the obtained sample was measured by X-ray diffraction, it was a composite of titanium carbide TiC, titanium oxide TiO, and glassy carbon. The density and flexural strength of this sample were 1.70 g / cm ³ and 1230 kg / cm ² , respectively.

(Comparative Example 1) In order to evaluate the test results for Examples 1 to 4, an alumina-based ceramic (manufactured by Nippon Electric Glass Co., Ltd., trade name "Neoceram") was used as Comparative Example 1.

Comparative Example 2 Similarly, calcium titanate (trade name “TC-105” manufactured by Sumitomo Special Metals Co., Ltd.) was used as Comparative Example 2.

(Comparative Example 3) In the same manner as in Example 1, 2 parts by weight of silicon carbide ultrafine particles were added to the thermosetting resin precondensate obtained in Example 1 and dispersed and mixed with a sand mill. No silane coupling agent was added. This was heat-treated at 1200 ° C. in the same manner as in Example 1, and was treated at 1400 ° C. and 2000 atm with a HIP apparatus.

When the obtained sample was measured by X diffraction, it was a composite of α-type silicon carbide and glassy carbon. The density and flexural strength of this sample were 1.68 g / cm ³ and 125, respectively.
It was 0 kg / cm ² .

(Comparative Example 3) In the same manner as in Example 2, delta-alumina ultrafine particles having an average primary particle size of about 0.02 μm (Nippon Aerosil Co., Ltd.) were added to the thermosetting resin precondensate obtained in Example 1. Aluminum oxide C) was added at a ratio of 2% by weight, and further, 0.2% of 3-glycidoxypropyltrimethoxysilane was added to the thermosetting resin and dispersed and mixed by a sand mill. Thereafter, similarly to Example 1, firing at 1200 ° C.
The treatment was performed at 1400 ° C. and 2000 atm with a HIP device.

When the obtained sample was measured by X diffraction, it was a composite of delta alumina and glassy carbon. The density and bending strength of this sample were 1.65 g / cm ³ and 126, respectively.
It was 0 kg / cm ² .

(Test Example 1) The samples obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were processed, and the friction coefficient and the wear amount were measured.

(I) Measurement of friction coefficient FIG. 1 shows the shape of a test piece used for measurement of the friction coefficient. For these test pieces, the samples obtained in the above Examples 1 to 4 and Comparative Examples 1 to 4 were 4.0 mm long a, 6.0 mm wide b,
A rectangular parallelepiped having a height h of 3.0 m was cut out, and the sliding surface A was gradually polished from rough polishing to fine polishing, and finally mirror-finished with emery paper # 15000. Further, the ridge surrounding the sliding contact surface A of the rectangular parallelepiped is chamfered with low-numbered emery paper, and then gradually radiused to 0.2 to 0.3 mm using high-numbered emery paper.
The test piece for measuring the coefficient of friction was rounded.

Using these test pieces, the coefficient of friction was measured by the so-called “pin disk method”. That is, a test piece for measuring the coefficient of friction was mounted on a gimbal spring used for a floppy disk drive, a load of about 20 g was applied from above, and a friction was applied to the spindle rotating at an arbitrary speed and the floppy disk mounted on a rotating plate. Slided. At this time, the frictional force was obtained by a strain gauge attached to the arm of the apparatus, and the friction coefficient μ was calculated.

As the disk, γ-Fe manufactured by Hitachi Maxell, Ltd.
_{A 2} O ₃ coated floppy disk (MD2-DD) and a flexible disk obtained by sputtering Co—Cr as a magnetic layer were used.

(Ii) Measurement of wear amount FIG. 2 shows the shape of a test piece used for measurement of the wear amount.
These test specimens have a width w in the lateral direction on a sliding surface A of the specimen used for the measurement of the friction coefficient by a slicing machine.
The groove is formed with a depth d of 0.5 μm and a depth d of several μm.
The distance r from the end of this groove is 2.0 mm. The cross-sectional curve of the groove was determined using a precision roughness measuring instrument (HIPOSS ET-10 manufactured by Kosaka Laboratory Co., Ltd.), and the groove depth was measured. The test piece was mounted on a gimbal spring and mounted on the head of a floppy disk drive. A load of 20 g was applied to the test piece to cause friction sliding with the floppy disk, and the head was moved by one track per rotation of the floppy disk to wear the test piece.

The groove depth of the test piece was measured over time to determine the wear depth.

(Iii) Test results The above test results are shown in Tables 1 and 2. Table 1 shows the test results of Examples 1 to 4, and Table 2 shows Comparative Examples 1 to 4.
4 shows the test results. In these tables, "addition amount"
Indicates the volume part of the additive with respect to 100 parts by volume of glassy carbon, and "A" in the column of "disc type" indicates
Indicates a Fe ₂ O ₃ coated floppy disk, also denoted by “B”
Indicates a Co-Cr sputter disk.

Regarding the amount of wear, in the case of a γ-Fe ₂ O ₃ coating type floppy disk, the depth of wear after 200 hours was measured, and Co-C
r In the case of a sputter disk, the depth of wear after 100 hours was measured.

(Test Example 2) The material prepared in Examples 3 and 4 was cut into square bars of 2 mm x 2 mm x 20 mm, and 2 mm x 2 mm using a precision lathe and a spherical polishing machine.
The surface of mm was processed into a spherical surface with a radius of curvature of 20 mm, and cut into a length of 3 mm.

In order to evaluate this material, a test was performed by replacing the head portion of the 2-inch flexible magnetic disk drive with the above-mentioned material. That is, a 2-inch metal-coated medium (manufactured by Sony Corporation) was used, the head protrusion amount was 60 μm, and the medium was rotated at a peripheral speed of 7.5 m / sec. In this state, the head portion was moved by one track each time the medium rotated once, and this was repeated 10 million times. After this, visual observation revealed no damage to the flexible magnetic disk.

(Test Example 3) The materials of Examples 1 to 4 were processed into the shape shown in Fig. 3 and mounted as shown in Fig. 4 to perform a test. That is, a groove was cut out at a length of a = 18 mm, a width of b = 12 mm, and a height of h = 2.5 mm, and a groove having a depth of d = 0.5 mm was provided in a horizontal direction on the upper surface. This sliding contact part was used as a pad 1, and a magnetic head 2 was projected into a groove of the pad 1, and a flexible magnetic disk 3 was passed between the pad 1 and the magnetic head 2 to perform a durability test. The flexible magnetic disk 3 was rotated at 3600 rpm, and the position of the magnetic head 2 was 20 mm from the center of rotation. The peripheral speed at this time is 7.54 mm. The protrusion amount p of the magnetic head 2 is 60
μm. As the magnetic head 2, a 2-inch video floppy disk was used, and as the flexible magnetic disk 3, a 2-inch metal-coated video floppy (manufactured by Sony Corporation) was used.

The magnetic head 2 was moved by one track each time the flexible magnetic disk 3 made one rotation, and this was repeated 10 million times. Upon visual observation, no damage was found on the flexible magnetic disk 3, and stable output characteristics were obtained. Microscopic observation also confirmed that pad 1 had substantially no wear. The running stability was also very good.

(Test Example 4) The material of Example 3 was processed into a thin plate having a thickness of 0.5 mm,
The surface was finally mirror-finished with a # 10000 alumina grinding wheel.

To measure the coefficient of friction of this material against the raw magnetic tape, fix the magnetic tape on a flat surface plate with adhesive tape, fix the material to be measured with a jig and make surface contact with the magnetic tape surface, Pulled by Tensilon. The relative speed with respect to the magnetic tape was set to 200 mm / min, and the friction coefficient was determined from the ratio of the weight of the material to the tension.

An audio cassette was assembled by inserting a molded body of the material to be measured so as to be in sliding contact with the edge of the magnetic tape between the cassette tape and the inner wall of the cassette, and the winding torque of the audio cassette was measured.

The friction coefficient was 0.10 to 0.13, which was 80% or less as compared with a commercially available graphite filler solidified with a resin. The winding torque was 1.5 to 8.5 gcm, which was about 70% of the value obtained by solidifying a commercially available graphite filler with a resin.

This property of the material indicates that it can be applied not only to the slide sheet in the cassette but also to the guide pins and cylinders of the magnetic tape device.

〔The invention's effect〕

As described above, the glassy carbon composite material of the present invention is a material that is excellent in wear resistance, has a small coefficient of friction, and can be processed precisely. It is also excellent in strength.

When sliding contact parts are manufactured using the glassy carbon composite material of the present invention, lubricating properties can be maintained for a long time without using a lubricant between the mating material and the surface of the mating material. An excellent effect can be obtained without damaging the material and with less wear of the material itself. In addition, since the glassy carbon as the main component has conductivity, static electricity is not generated, and there is an effect that dust hardly adheres to a partner material and a contact portion thereof.

Further, the glassy carbon composite material of the present invention can be used for fuel cell separators, mechanical parts, various jigs, and the like by utilizing its strength.

[Brief description of the drawings]

FIG. 1 is a view showing the shape of a test piece used for measuring a friction coefficient. FIG. 2 is a view showing a shape of a test piece used for measuring a wear amount. FIG. 3 is a view showing the shape of a test piece used in Test Example 3. FIG. 4 is a diagram showing a test method of Test Example 3.

Claims (8)

(57) [Claims] 1. A glassy carbon composite material containing glassy carbon as a main component and ultrafine particles having an average particle diameter of 1 μm or less as a reinforcing component, wherein the ultrafine particles are α-alumina ultrafine particles, and titanium carbide.
A glassy carbon composite material comprising at least one of a titanium compound ultrafine particle composed of TiC and titanium oxide TiO _x . However, x = 1 to 2. 2. The glassy carbon composite material according to claim 1, wherein the molar ratio between titanium carbide TiC and titanium oxide TiO _{x in the} titanium compound ultrafine particles is TiC / TiO _x = 0.01 to 100. 3. The ultrafine particles are silicon carbide SiC and silicon oxide SiO.
_2. The glassy carbon composite material according to claim 1, which is a material coated with at least one of ( ₂₎ and (3). 4. The glassy carbon composite material according to claim 1, wherein the content of the ultrafine particles is 0.005 to 0.2 in volume ratio to the glassy carbon. 5. A curing precursor of a thermosetting resin having an average particle size of 1
a hardening step of mixing and hardening ultrafine particles of not more than μm, and a carbonizing step of heating and carbonizing the resin obtained in the hardening step, wherein the ultrafine particles are α- The carbonization step includes at least one of alumina ultrafine particles and titanium oxide ultrafine particles, and the carbonization step includes a pretreatment step of performing a heat treatment at 800 to 1200 ° C. A pressure heat treatment step of heat-treating at a temperature of 1700 ° C. to 1700 ° C. 6. The method for producing a glassy carbon composite material according to claim 5, further comprising a step of subjecting the ultrafine particles to a surface treatment with a silane coupling agent. 7. A curing precursor of a thermosetting resin having an average particle size of 1
a hardening step of mixing and hardening ultrafine silicon carbide particles having a particle size of not more than μm, and a carbonizing step of heating and carbonizing the resin obtained in the hardening step. The carbonization step includes a pre-treatment step of heat treatment at 800 to 1200 ° C., and after this step, a step of applying a pressure of 1,000 atm or more in an inert atmosphere to the carbonization step. A pressure heat treatment step of heat-treating at 1700 ° C., comprising: 8. The glass according to claim 1, wherein at least a sliding contact surface is provided on a movable portion of the mechanical element and slides relatively or temporarily while always in contact. A sliding contact part characterized by being formed of a carbon-like composite material.