JP5325070B2 - Fluorinated carbon fine particles - Google Patents

Description

  The present invention relates to fluorinated carbon fine particles. More specifically, for example, plating materials, paints, abrasives, lubricants, heat exchange fluid media, composite materials with resins and metals, electronic materials such as low dielectric films and emitter materials, DNA carriers, carriers for capturing viruses, etc. The present invention relates to a fluorinated carbon fine particle expected to be used for applications such as medical materials, a manufacturing method thereof, and a composite plating material containing the fluorinated carbon fine particle.

  Carbon fine particles having a primary particle size of several nanometers are expected to be applied to various applications by taking advantage of the size of the particles. For example, carbon fine particles typified by nanodiamond particles improve the wear resistance of plating films and coating films, and are therefore considered to be used for plating materials and paints.

  However, carbon fine particles, especially diamond fine particles with a primary particle size of several nanometers to several tens of nanometers, agglomerate very strongly, and usually exist as aggregates having a particle diameter of the order of micrometers. Yes. Therefore, the aggregated carbon fine particles not only have a poor dispersion stability in the plating material or paint, but also inhibit the smoothness of the plating film or coating film. It must be crushed and dispersed uniformly.

  As a dispersion of nanodiamond particles, an aggregate of nanodiamond particles is added to a mixed solvent of water and ethanol, a polymer azo polymerization initiator containing a polyethylene glycol unit is added thereto, and then heated. Proposed dispersions of nanodiamond particles and nanodiamond particle dispersions in which nickel sulfate is added to micelles composed of aggregates and polymers of nanodiamond particles have been proposed (for example, see Patent Document 1). However, these nanodiamond particle dispersions contain components other than nanodiamond particles, and have a drawback that these components act as impurities in plating materials and paints.

  As another nanodiamond particle dispersion liquid, a nonaqueous dispersion liquid of nanodiamond particles obtained by wet-pulverizing a mixture of nanodiamond particle aggregates and a nonaqueous liquid medium with a bead mill has been proposed. (For example, refer to Patent Document 2). However, since this non-aqueous dispersion of nanodiamond particles is obtained by wet pulverization with a bead mill, the dispersion stability is inferior over a long period of time, and aggregation occurs when used for plating materials containing ions. There is a disadvantage that it occurs.

  In recent years, fluorinated nanodiamond particles have attracted attention because they are useful as precision abrasives. However, fluorinated nanodiamond particles do not leak into examples and usually exist as aggregates. Inferior to Therefore, as a dispersion of fluorinated nanodiamond particles with improved dispersion stability of the fluorinated nanodiamond particles, a suspension of an aggregate of fluorinated nanodiamond particles and a liquid having a viscosity at 20 ° C. of 2.5 cP or less. Dispersion of the fluorinated nanodiamond particles obtained by classifying the obtained suspension and mixing the dispersion obtained by this classification with a liquid dispersion having a viscosity at 20 ° C. of 4 cP or more A liquid has been proposed (see, for example, Patent Document 3). However, this dispersion of fluorinated nanodiamond particles requires not only two types of solvents having different viscosities in order to produce the dispersion, but also has the disadvantage that the production process is complicated, To remove the fluorinated nanodiamond particles from the dispersion of fluorinated nanodiamond particles, the solvent is removed from the dispersion and the fluorinated nanodiamond particles are re-agglomerated when the fluorinated nanodiamond particles are dried. There is a drawback.

JP 2008-150250 A JP 2005-97375 A JP 2009-190902 A

The present invention, wherein has been made in view of the prior art, dispersed without aggregating in water, fluorinated carbon particles can be produced superior fluorinated carbon fine particles in the dispersion stability by a simple operation it is an object of the present invention to provide a manufacturing how.

The present invention provides a method for producing a fluorinated fluorinated carbon particulates from the carbon granules child, the carbon particles become aggregated primary particles of the diamond fine particle size is 1 to 30 nm, the particles An aggregate of diamond fine particles having a diameter of 0.1 to 10 μm, wherein the aggregate is fluorinated at a temperature of 5 to 200 ° C. under a reduced pressure of 0.1 to 80 kPa in a fluorine gas atmosphere. about the production how of fluorinated carbon particles.

  According to the present invention, it is possible to produce fluorinated carbon fine particles that are dispersed without being aggregated in water and that are excellent in dispersion stability by a simple operation. In addition, the composite plating material of the present invention is a plating film formed from the plating material because the fluorinated carbon fine particles contained therein are dispersed without being aggregated in the plating material and are excellent in dispersion stability. Is excellent in abrasion resistance and composition uniformity.

2 is a scanning electron microscope (SEM) photograph of the fluorinated nanodiamond particles obtained in Examples 1 to 3 and Comparative Example 2 and the nanodiamond particles of Comparative Example 1 before fluorination. The C1s spectrum and F1s spectrum by X-ray optical spectroscopy (XPS) of the fluorinated nanodiamond particles obtained in Examples 1 to 3 and Comparative Example 2 and the nanodiamond particles before fluorination of Comparative Example 1 are shown. FIG. 6 is a drawing-substituting photograph before and after ultrasonic irradiation of a dispersion liquid of fluorinated nanodiamond particles obtained in Example 4. FIG. 4 is a graph showing the particle size distribution of fluorinated nanodiamond particles in a dispersion of fluorinated nanodiamond particles obtained in Example 4. 6 is a powder X-ray diffraction pattern of fluorinated nanodiamond particles obtained in Reference Example 2. FIG.

  In general, the carbon fine particles exist as aggregates on the order of micrometers. Among them, nanodiamond particles, which are diamond fine particles with a primary particle size of several nanometers to several tens of nanometers, are very strongly aggregated, and secondary diamond particles with a particle size of several micrometers or tertiary nanodiamond particles. It exists as an aggregate.

  The inventors of the present invention have intensively studied as a technical issue how to disintegrate aggregates of carbon fine particles, particularly nanodiamond particles, and disperse them in an aqueous solution close to primary particles. Surprisingly, when carbon fine particles are fluorinated in a fluorine gas atmosphere depressurized to a specific degree of decompression, the resulting fluorinated carbon fine particles are dispersed without agglomeration in water, and dispersion stability is improved. It was found to be excellent. The present invention has been completed based on such findings.

  As described above, the method for producing fluorinated carbon fine particles of the present invention is a method for producing fluorinated carbon fine particles in which carbon fine particles are fluorinated, and the aggregate of carbon fine particles is 0.1 to 80 kPa in a fluorine gas atmosphere. Fluorinated under reduced pressure. Since the fluorinated carbon fine particles obtained by the production method of the present invention are dispersed without agglomerating in water, for example, even when used in plating materials, paints, etc., they can be dispersed uniformly. The formed plating film or coating film is excellent in wear resistance and composition uniformity.

  Examples of the carbon fine particles include diamond fine particles, graphite fine particles, and fullerene fine particles. However, the present invention is not limited to such examples. The carbon fine particles may be hydrogenated if necessary.

  According to the production method of the present invention, among the carbon fine particles, the aggregates of nanodiamond particles formed by very strong aggregation of the primary particles of the diamond fine particles are also uniformly dispersed without being aggregated in water. Fluorinated nanodiamond particles can be produced, and the aqueous dispersion has excellent dispersion stability. The diamond fine particles contain, for example, a compound having a 4 to 15 carbon ring such as adamantane, a carbon raw material such as fullerene or carbon nanotube, and an explosive component as described in WO 2007/001031. Can be produced by exploding the explosive composition in a closed container or in water.

  The particle diameter of primary particles of carbon fine particles is usually several nanometers to several tens of nanometers. For example, diamond fine particles are generally produced by an impact compression method, and the primary particles have a particle size of 1 to 30 nm. Moreover, the particle diameter of the primary particles of the diamond fine particles obtained by the oxygen-deficient detonation method is usually about 3 to 8 nm. These diamond fine particles are generally referred to as nanodiamond particles.

  Aggregates of carbon fine particles used as a raw material are secondary particles or tertiary particles in which primary particles of carbon fine particles are aggregated, and usually have a particle diameter of about 0.1 to 10 μm.

  In fluorinating the aggregate of carbon fine particles, if the carbon fine particles contain moisture, there is a possibility that the moisture and fluorine react when the carbon fine particles are fluorinated. Therefore, when the carbon fine particles contain moisture, it is preferable to dry the carbon fine particles in advance. Examples of the method for drying the carbon fine particles include a reduced pressure drying method, a heat drying method, a drying method using a dehumidifying agent, and the like, but the present invention is not limited to such examples.

  The fluorination of the carbon fine particle aggregate is performed in a fluorine gas atmosphere. The fluorine gas atmosphere can be formed, for example, by removing the atmosphere by depressurizing the internal space of the reaction vessel that can form a closed space, and then introducing the fluorine gas into the internal space. Although it can be formed by a method of replacing the atmosphere with fluorine gas by directly introducing fluorine gas into the internal space of the reaction vessel, the present invention is not limited to such a method.

  When a reaction vessel capable of forming the closed space is used, it is preferable from the viewpoint of safety that the aggregates of carbon fine particles are fluorinated after the aggregates of carbon fine particles are placed in the reaction vessel.

  The fluorine gas atmosphere referred to in this specification is not limited to an atmosphere formed of only fluorine gas, but is within a range in which the object of the present invention is not impaired, for example, an inert gas such as helium gas, argon gas, nitrogen gas, etc. Means an atmosphere formed of fluorine gas diluted with Among these, from the viewpoint of increasing the efficiency of fluorination, it is preferable that the fluorine gas partial pressure in the fluorine gas atmosphere is high.

  When the carbon fine particle aggregate is fluorinated in a fluorine gas atmosphere, the pressure of the fluorine gas atmosphere in the fluorine gas atmosphere is controlled to a predetermined value of 0.1 to 80 kPa. In the present invention, there is one major feature in that the pressure of the fluorine gas atmosphere is controlled to a predetermined value as described above. Since the pressure of the fluorine gas atmosphere is controlled to be a predetermined value, It is possible to obtain fluorinated carbon fine particles that are dispersed without being dispersed and excellent in dispersion stability.

  The pressure of the fluorine gas atmosphere is from 0.1 to 80 kPa, preferably from 0.1 to 60 kPa, more preferably from the viewpoint of efficiently producing fine fluorinated carbon fine particles that are dispersed without being aggregated in water and are excellent in dispersion stability. Is 0.1 to 55 kPa, more preferably 0.3 to 55 kPa.

  The temperature of the fluorine gas atmosphere when the carbon fine particle aggregate is fluorinated is not particularly limited, but from the viewpoint of efficiently producing fine fluorinated carbon fine particles that are finely dispersed without being aggregated in water and excellent in dispersion stability. The temperature is preferably 0 to 500 ° C, more preferably 5 to 450 ° C, still more preferably 5 to 400 ° C, still more preferably 5 to 200 ° C, and particularly preferably 10 to 100 ° C.

  The fluorination of the aggregates of the carbon fine particles is preferably performed until the carbon atoms by the carbon fine particles are not detected by, for example, X-ray optical spectroscopic analysis.

  The time required for the fluorination of the carbon fine particle aggregate varies depending on the pressure and temperature of the fluorine gas atmosphere, the amount of the carbon fine particle aggregate, and the like, and therefore cannot be determined unconditionally. Usually, the time required to fluorinate the carbon fine particle aggregate in a fluorine gas atmosphere is finely dispersed without agglomerating in water and from the viewpoint of efficiently producing fluorinated carbon fine particles having excellent dispersion stability. Preferably it is 0.3-5 hours, More preferably, it is 0.5-3 hours, More preferably, it is 0.5-1.5 hours.

  By fluorinating the aggregate of carbon fine particles as described above, fluorinated carbon fine particles can be produced. The obtained fluorinated carbon fine particles, as will be clarified by the following examples, at least the surface of the particles are fluorinated, but the fluorination has not progressed to the center, Since the surface is appropriately fluorinated, it is considered that the surface is dispersed without agglomerating in water and is excellent in dispersion stability. The fluorinated carbon fine particles of the present invention are basically the same as the shape and size of the carbon fine particles before fluorination except that at least the surface of the particles is fluorinated.

  In addition, fluorine gas adheres to the surface of the obtained fluorinated carbon fine particles, and from the viewpoint of avoiding the reaction between the fluorine gas and moisture in the atmosphere, before removing the fluorinated carbon fine particles into the air. Moreover, it is preferable to remove the fluorine gas adhering to the surface with an inert gas. For example, when the reaction vessel is used, the fluorine gas adhering to the surface of the fluorinated carbon fine particles can be removed by replacing the fluorine gas in the reaction vessel with an inert gas. Examples of the inert gas include helium gas, argon gas, and nitrogen gas, but the present invention is not limited to such examples.

  The composite plating material of the present invention contains the fluorinated carbon fine particles. In this specification, the composite plating material means that the fluorinated carbon fine particles of the present invention are included in addition to a normal plating material.

  The plating material used in the composite plating material of the present invention is not particularly limited as long as it is a commonly used plating material such as a water-based plating bath. For example, nickel sulfamate aqueous solution etc. are mentioned.

  Although the content of the fluorinated carbon fine particles in the composite plating material of the present invention varies depending on the use of the composite plating material and the like, it cannot generally be determined. However, usually, the plating film has high hardness and imparts wear resistance. From this point of view, it is preferably in the range of about 0.05 to 10% by weight.

  The composite plating material of the present invention contains the fluorinated carbon fine particles, and the fluorinated carbon fine particles are dispersed without being aggregated in the plating material and are excellent in dispersion stability. The formed plating film is excellent in wear resistance and composition uniformity.

  Next, the present invention will be described in more detail based on examples, but the present invention is not limited to such examples.

Examples 1-3 and Comparative Examples 1-2
Nano diamond particles as carbon fine particles [manufactured by Nippon Kayaku Co., Ltd., hydrogenated nano diamond particles, trade name: Ustalla-Type C, average particle size of primary particles: 4 nm ± 1 nm, average particle size of secondary particles: 0.00. 5 μm ± 0.5 μm] 1.0 g was put in a nickel reaction tube, and after putting this reaction tube in a reaction vessel, the inside of the reaction vessel was depressurized to 1.0 × 10 ⁻¹ Pa at room temperature to obtain nanodiamonds. The particles were dried. The appearance of the dried nanodiamond particles was observed with a scanning electron microscope (SEM). The scanning electron micrograph is shown in FIG. 1 (a) (Comparative Example 1).

  Next, the fluorine gas is used until the pressure of the fluorine gas reaches 0.67 kPa (Example 1), 13.3 kPa (Example 2), 50.7 kPa (Example 3), or 101.3 kPa (Comparative Example 2) at room temperature. Was introduced into the reaction vessel, and fluorination of the nanodiamond particles was performed for 1 hour. Then, argon gas was introduced into the reaction vessel to perform argon gas substitution, and the reaction tube was taken out of the reaction vessel.

  Fluorinated nanodiamond particles (fluorinated nanodiamond particles) were taken out from the reaction tube, and the appearance was observed with a scanning electron microscope. Scanning electron micrographs of nanodiamond particles fluorinated at a fluorine gas pressure of 0.67 kPa, 13.3 kPa, 50.7 kPa, or 101.3 kPa are shown in FIG. 1B to FIG. 1E, respectively. In addition, the scale in each photograph is shown in the lower right of each photograph.

  From the results shown in FIG. 1, in the nanodiamond particles before fluorination (Comparative Example 1), almost no primary particles are observed [FIG. 1 (a)], and fluorinated at a fluorine gas pressure of 101.3 kPa. In the nanodiamond particles, it can be seen that a small amount of fine particles which have been crushed and approached the primary particles are present [FIG. 1 (e)]. On the other hand, in the nanodiamond particles fluorinated with a fluorine gas pressure of 0.67 to 50.7 kPa, it can be seen that a large number of microparticles close to primary particles exist [FIG. d)].

  Next, the fluorinated nanodiamond particles obtained in Examples 1 to 3 and Comparative Example 2 and the nanodiamond particles before fluorination of Comparative Example 1 were each separately 0.1 parts by mass per 100 parts by mass of water. When a dispersion was prepared by irradiating with ultrasonic waves for 1 hour with an ultrasonic cleaner, the dispersion containing the fluorinated nanodiamond particles obtained in Examples 1 to 3 was added. Became transparent.

  When the particle diameter of the fluorinated nanodiamond particles contained in the dispersion liquid of the fluorinated nanodiamond particles obtained in Examples 1 to 3 was measured, the particle diameter of the primary particles was about 10 nm or less. It was found that it was crushed into particles of a size close to.

  From the above, by controlling the pressure of the fluorine gas when fluorinating the nanodiamond particles, the primary particles of the spherical fluorinated nanodiamond particles or the particle diameter of the primary particles is close to the nanodiamond particles. It can be seen that fine secondary particles crushed to size can be formed.

  Next, X-ray photoelectron spectroscopy (XPS) of the nanodiamond particles before fluorination of Comparative Example 1 and the fluorinated nanodiamond particles obtained in each Example and Comparative Example 2 was performed. At that time, an X-ray photoelectron spectroscopy analyzer [manufactured by JEOL Ltd., product number: XPS-9010] was used, and X-ray photoelectron spectroscopy was performed under the conditions of X-ray: Mg-Kα ray, voltage: 10 kV, current: 2.5 mA. Analysis was performed. The charge correction was performed based on the binding energy of carbon 1s electrons. The C1s spectrum and F1s spectrum obtained by X-ray photoelectron spectroscopy (XPS) are shown in FIGS. 2 (a) and 2 (b), respectively.

  2A and 2B, p is the data of Comparative Example 1, q is the data of Example 1, r is the data of Example 2, s is the data of Example 3, and t is the data of Comparative Example 2. Indicates.

From the results shown in FIG. 2 (a), for the C1s electrons, the peak near the bond energy (BE) 288 eV to the nucleus is a carbon atom (—CHF— or —) bonded to one or more fluorine atoms. It is derived from CF _2- ) and is considered to have moved to a higher energy side by bonding with fluorine as compared with a peak derived from a carbon atom in pure diamond (around 285 eV).

  In addition, when reacted with fluorine gas, as the pressure increases, the binding energy (BE) to the nucleus increases for C1s electrons, and fluorine is sequentially introduced onto the surface of the nanodiamond particles. I understand that.

However, when the pressure of the fluorine gas increases, the peak top shifts to a lower energy side, and finally shows an asymmetric profile having a peak near the binding energy 289 eV to the nucleus. This is because, due to the introduction of an excessive amount of fluorine exceeding the number of bonds on the surface of the nanodiamond particles, partial bond breakage occurs, and carbon atoms having a bond state of —CHF— or —CF ₂ — are generated. As a result, a small amount of bonding state such as —CF ₃ is generated, and as a result, a peak of carbon atoms having a bonding state of —CHF— or —CF ₂ — in the vicinity of a binding energy of 288 eV to the nucleus and a basic structure inside the particle In addition to the peak near the bond energy 285 eV to the nucleus derived from the carbon supporting the carbon, the peak near the bond energy 290 eV to the nucleus derived from the carbon having the bond state of —CF ₃ is changed to a carbon atom in each bond state. The result is the addition of a strength ratio proportional to the concentration ratio on the sample surface and the appearance as a composite shape it is conceivable that.

  In addition, from the result shown in FIG. 2B, a peak in the vicinity of 689 eV of binding energy to the nucleus for the F1s electron considered to be based on the C—F bond is observed, and the intensity increases the pressure of the fluorine gas. Increased by doing.

  From the above, it can be seen that more fluorine is introduced to the surface of the nanodiamond particles as the pressure of the fluorine gas during the reaction increases.

Further experiments were conducted, and Ar ⁺ etching was performed on nanodiamond particles (Example 2) fluorinated at a fluorine gas pressure of 13.3 kPa. Both the C1sXPS spectrum and the F1sXPS spectrum were the same as before fluorination. Similar to the nanodiamond particles (Comparative Example 1). From this, it is considered that the fluorination proceeds only on the very surface of the nanodiamond particles, and the inside thereof is not fluorinated.

Example 4 and Comparative Example 3
In Example 1, the pressure of the fluorine gas and the fluorination time were changed from 0.67 kPa for 1 hour to 1.3 kPa for 1 hour (Example 4) or 101.32 kPa for 12 hours (Comparative Example 3). Except for the above, fluorinated nanodiamond particles were produced in the same manner as in Example 1.

  The fluorinated nanodiamond particles obtained in Example 4 are put into water at a ratio of 0.1 parts by mass per 100 parts by mass of water, and the resulting mixed solution is put into a transparent glass container and shaken lightly. Thus, a dispersion liquid was obtained. A drawing-substituting photograph of the obtained dispersion is shown in FIG. Moreover, the particle size distribution after leaving this dispersion for 24 hours was measured using a dynamic light scattering particle size distribution meter. The result is shown in FIG.

  Next, when this dispersion was irradiated with ultrasonic waves for 1 hour with an ultrasonic cleaner, the dispersion became transparent. A drawing-substituting photograph of the dispersion is shown in FIG. Further, the particle size distribution after leaving this dispersion for 24 hours was measured in the same manner as described above. The result is shown in FIG.

  From the result shown in FIG. 3B, it can be seen that the fluorinated nanodiamond particles obtained in Example 4 can be uniformly dispersed in water.

  Further, from the results shown in FIGS. 4A and 4B, the particle diameter of the fluorinated nanodiamond particles contained in the dispersion liquid of the fluorinated nanodiamond particles obtained in Example 4 is It can be seen that when dispersed with a sonic wave so as to have a uniform composition, the particles are crushed into particles having a size close to the particle size of primary particles of about 10 nm or less, and the dispersed state is maintained.

  From these, by dispersing fluorinated nanodiamond particles in water so as to have a uniform composition, primary particles or particles crushed to a size close to primary particles are generated, and the particles are stable. It can be seen that they are dispersed.

Reference example 1
In Example 1, except that the pressure of the fluorine gas was changed from 0.67 kPa to 6.66 kPa and the temperature at the time of fluorination was changed from room temperature to 400 ° C., it was fluorinated in the same manner as in Example 1. Nano-diamond particles were produced.

  Next, the powder X-ray diffraction of the fluorinated nanodiamond particles obtained above was examined. The powder X-ray diffraction was the same as the powder X-ray diffraction of the nanodiamond particles before fluorination in Comparative Example 1. It was the same. From this, it can be seen that even if the nanodiamond particles are fluorinated, the internal structure of the nanodiamond particles is not affected.

  The powder X-ray diffraction was measured using a powder X-ray diffraction measurement apparatus [manufactured by Shimadzu Corporation, trade name: powder X-ray diffraction measurement apparatus XD-6100]. : 40 kV, current: 30 mA, scanning mode: continuous scanning, scanning range: 40 to 160 °, scanning speed: 2.0 ° / min, atmosphere: air.

Reference example 2
The resulting fluorinated nanodiamond particles in Reference Example 1, further pressure 6.66kPa similar to a fluorine gas as in Reference Example 1, at a temperature 400 ° C. during the fluorination, repeated four times an operation of fluorinated Thereafter, the powder X-ray diffraction was examined. The powder X-ray diffraction pattern is shown as x in FIG.

  For reference, the powder X-ray diffraction of the nanodiamond particles of Comparative Example 1 before fluorination was also examined. The powder X-ray diffraction pattern is shown in y of FIG.

As shown in FIG. 5, the fluorinated nanodiamond particles obtained in Reference Example 2 were subjected to fluorination five times, and the X-ray diffraction of the fluorinated nanodiamond particles was compared. This was similar to the X-ray diffraction of nanodiamond particles before fluorination in Example 1.

  From this, even if the nanodiamond particles are fluorinated, the crystal structure thereof does not change. Therefore, it is considered that the fluorination proceeds only on the very surface of the nanodiamond particles and the inside thereof is not fluorinated.

Experimental example 1
0.01 g each of the fluorinated nanodiamond particles obtained in Examples 1-4, the nanodiamond particles of Comparative Example 1 and the fluorinated nanodiamond particles obtained in Comparative Examples 2-3 Weigh each sample in a separate test tube together with 10 mL of water, and irradiate with ultrasonic waves for about 1 hour with an ultrasonic cleaner to disperse the mixture so that it has a uniform composition with sufficient stirring at room temperature. A dispersion was obtained. In order to rapidly disperse the nanodiamond particles, a technique such as bead milling can be used.

  As physical properties of the obtained dispersion, dispersion stability and zeta potential were examined based on the following methods. The results are shown in Table 1. In Comparative Examples 2 and 3, since the dispersion stability was poor, the zeta potential was not measured.

(Dispersion stability)
The dispersion obtained above was held vertically and allowed to stand, and after 24 hours, the diameter of the precipitate formed at the round bottom of the test tube was measured and evaluated based on the following evaluation criteria.
(Evaluation criteria)
○: The diameter of the precipitate is less than 3 mm Δ: The diameter of the precipitate is 3 mm or more and less than 10 mm x: The diameter of the precipitate is 10 mm or more

[Zeta potential]
The zeta potential of the nanodiamond particles in the dispersion was determined using a zeta potential measurement system [manufactured by Otsuka Electronics Co., Ltd., product number: ELSZ-2].

  From the results shown in Table 1, the fluorinated nanodiamond particles obtained in each example are the same as the nanodiamond particles in Comparative Example 1 and the fluorinated nanodiamond particles obtained in Comparative Examples 2 to 3. In contrast, it can be seen that the dispersion stability in the supernatant is good and the dispersion stability in the dispersion is excellent.

  Further, since the zeta potential in the supernatant and dispersion obtained in each example is equivalent to that in Comparative Example 1 and is a positive value, the fluorinated nanoparticle obtained in each Example It can be seen that none of the diamond particles cause a decrease in eutectoid efficiency when used for composite plating by eutectoid with metal ions (positive ions).

  Furthermore, the particle diameter in the dispersion liquid of the (fluorinated) nanodiamond particles obtained in each comparative example is mainly 100 nm or more, whereas the fluorinated nanodiamond particles obtained in each example. The particle size in the dispersion was about 10 nm. This shows that the fluorinated nanodiamond particles obtained in each example are excellent in dispersion stability.

  From the above, each of the fluorinated nanodiamond particles obtained in each example has both a good dispersion state and a charge state suitable for the plating process. It can be seen that it is suitable for a composite plating solution containing nanodiamond particles at a high concentration.

Experimental example 2
1.0 g of the fluorinated nanodiamond particles obtained in Example 4 and Comparative Example 3 are separately added to 100 mL of a 60 wt% aqueous nickel sulfamate solution, and sufficiently stirred to have a uniform composition. A plating bath was prepared.

A constant-current power source was soaked in the plating bath obtained by immersing two electrodes, a nickel plate as an anode and an iron-made hull cell plate (surface area: 18 cm ² ) treated with an alkali as a cathode, so that the current density was 0.05 Acm ^−1. While controlling the voltage using [Hokuto Denko Co., Ltd., product number: HA-105B], energization is performed between both electrodes until reaching a preset energization amount, and the nickel plating film has a film thickness of 1 μm. Formed. Thereafter, the electrode was removed from the plating bath, washed with pure water, and sufficiently dried.

  As physical properties of the plating film formed on the electrode, the wear resistance was examined based on the following method. As a result, the nickel plating film in which the fluorinated nanodiamond particles were combined was superior in wear resistance as compared to the nickel plating film in which the fluorinated nanodiamond particles were not combined.

[Measurement method of wear resistance]
Using a ball-on-disk friction tester (Resca Co., Ltd., product number: FPR-2000), press the stainless steel spheres with a constant load of 5 N against the plated film surface of the sample on which the plated film is formed. Was slid at a constant relative speed, and the wear resistance was evaluated by measuring the change of the friction coefficient with respect to the relative movement distance.

  In the nickel plating film composited with the fluorinated nanodiamond particles obtained in Example 4, the relative movement distance until the friction coefficient starts to be changed is 50 m, whereas the fluorine obtained in Comparative Example 3 is used. It was confirmed that the relative moving distance was 30 m, which was about 60%, in the nickel plating film in which the nanodiamond particles were combined.

  From this, it can be seen that by using the fluorinated nanodiamond particles obtained in Example 4, a composite plating film having excellent wear resistance can be formed.

  From the above results, according to the method for producing fluorinated carbon fine particles of the present invention, it is possible to produce fluorinated carbon fine particles that are dispersed without agglomerating in water and that are excellent in dispersion stability by a simple operation. Recognize. Moreover, since the composite plating material of the present invention disperses the fluorinated carbon fine particles contained therein without agglomerating in the plating material and is excellent in dispersion stability, the plating film formed from the plating material is It can be seen that the wear resistance is excellent.

The fluorinated carbon fine particles of the present invention include, for example, plating materials, paints, abrasives, lubricants, heat exchange fluid media, composite materials with resins and metals, electronic materials such as low dielectric films and emitter materials, DNA carriers, It is expected to be used for medical materials such as carriers for capturing viruses.

Claims (1)

A method of manufacturing a fluorinated fluorinated carbon particulates from coal elementary particle element, wherein the carbon particles become aggregated primary particles of the diamond fine particle size is 1 to 30 nm, particle size 0 Fluorinated carbon, characterized in that it is an aggregate of diamond fine particles of 1 to 10 μm, and the aggregate is fluorinated at a temperature of 5 to 200 ° C. under a reduced pressure of 0.1 to 80 kPa in a fluorine gas atmosphere. A method for producing fine particles.