TWI732823B - Method for manufacturing composite particles - Google Patents

Abstract

The purpose of the present invention is to provide a mirror surface that can realize the use of flow processing Grinding, long-term use, and less deterioration of performance over time, mainly used as abrasive composite particles, abrasive materials and composite particles manufacturing method using the composite particles. The composite particle of the present invention is characterized by including a plurality of particles including a material having a New Mohs hardness of 13 or more, and a resin containing polyvinyl alcohol. The material having a New Mohs hardness of 13 or more is preferably silicon carbide, and its resin preferably contains an elastomer.

Description

Method for manufacturing composite particles

The present invention relates to a composite particle mainly used as an abrasive grain, an abrasive material using the composite particle as an abrasive grain, and a method for producing the composite particle.

Silicon carbide (SiC, new mohs hardness: 13), boron carbide (B ₄ C, new mohs hardness: 14), diamond (new Mohs hardness: 15) and other materials are measured by new Mohs hardness With a high hardness of 13 or more, it can be used as a wire saw for cutting various ingots such as silicon and quartz or as free abrasive for wafer lapping.

In addition, the particle shape of these powders is usually a crushed shape in a pulverized state and becomes an indeterminate shape with sharp edges. Therefore, it is considered that the strong cutting force generated by the shape is effective for cutting or grinding. As this grinding process technology, jet processing in which the powder abrasive material collides with the object to be processed, or barrel grinding processing in which the object to be processed and the powder abrasive material are put into a drum and rotated, etc. are used.

Furthermore, in recent years, in order to perform surface grinding of parts with complex shapes, deburring of inner surfaces that cannot be reached by tools, R processing of edge parts, and processing of precision minute parts, a fluid (medium) in which abrasive grains are dispersed has also been used. ) The viscoelastic flow processing technology that presses and moves on the viscoelastic polymer material. In addition, all methods including wet and dry processing by flowing abrasive grains are referred to herein as "flow processing".

In these flow processing, the abrasive materials and abrasive grains can be selected according to the purpose, but the high hardness materials such as silicon carbide, boron carbide, diamond, etc. themselves cannot be used as the surface of the processed object due to the excessive cutting force and grinding force. Abrasive grains for mirror polishing that give gloss and polish it into a mirror surface.

Therefore, as abrasive grains for mirror polishing processing, materials such as alumina, zirconia, stainless steel, glass, etc., which are relatively spherical and have low hardness (New Mohs hardness of 12 or less) are used. However, even if these materials are used, when the processed object contains soft materials such as aluminum, copper, and plastic, the use conditions must be further limited.

However, as examples in which silicon carbide powder is used as an abrasive for fluid processing, for example, Patent Document 1 and Patent Document 2 are known. In Patent Document 1, in order to roughen the surface of parts made of stainless steel (SUS), titanium, aluminum, and molybdenum, an abrasive material of silicon carbide is used.

In addition, Patent Document 2 discloses a blast treatment method that can remove deposits without damaging the surface of the object to be treated. Here, the particle size of the abrasive grains containing silicon carbide or alumina is set to #400 to #800, and the pressure when the abrasive touches the surface of the object to be processed is further controlled.

According to Patent Document 1 and Patent Document 2, it is known that abrasive grains containing high-hardness materials such as silicon carbide are suitable for processing the surface to be rough or for cutting the surface. In the event of damage, the conditions of use must be extremely restricted.

On the other hand, in order to adjust the excessive grinding force of the abrasive grains, a method of using abrasive grains in combination with an elastic substance has been proposed. For example, Patent Document 3 discloses an abrasive material that allows abrasive grains to adhere to the surface of a water-containing core body such as gelatin. However, this abrasive material has the risk of losing water and lowering its performance due to long-term storage or use. worry. In addition, due to the solubility of the core body, there is also the disadvantage that it cannot be used for flow processing using water as a medium.

In addition, for example, Patent Document 4 discloses an abrasive material that can make the surface of an object to be processed mirror-finished and glossy-finished by spray processing. This is to attach and fix abrasive grains to the surface of an elastic core body as an abrasive. However, when manufacturing the abrasive, it is necessary to repeat the steps of attaching and pressing abrasive grains, and further requires a step of sieving abrasive grains. Therefore, there is a problem that the manufacturing steps are complicated. In addition, the abrasive grain layer on the surface is changed to a masonry structure, thereby prolonging the service life or suppressing performance degradation. However, if the abrasive grain layer carried on the surface is consumed, the abrasive grain layer must be lost as an abrasive material. Ability.

Furthermore, for example, Patent Document 5 and Patent Document 6 disclose an abrasive material in which abrasive grains are dispersed in an elastomer such as rubber, acrylic resin, or urethane resin. These abrasives have the advantage of simplifying manufacturing compared to abrasives that carry abrasive grains on the surface of the core body. However, these abrasives also have the following problem: the abrasive grains exposed on the surface wear out and the performance is deteriorated. The processing conditions will change when used repeatedly. In addition, since abrasive grains are also present in the elastomer, it is necessary to increase the proportion of the elastomer in order to obtain the desired elasticity. As a result, the number of abrasive grains exposed on the surface is reduced, so there is also a problem that the life as an abrasive material is shortened.

In this way, as for the abrasive materials used for mirror polishing by flow processing, several types of abrasive materials have been proposed so far, but there is still a problem of insufficient performance.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 11-28666

[Patent Document 2] Japanese Patent Laid-Open No. 2007-237389

[Patent Document 3] Japanese Patent Laid-Open No. 2001-207160

[Patent Document 4] International Publication No. VVO2013/094492

[Patent Document 5] Japanese Patent Publication No. 55-98565

[Patent Document 6] Japanese Patent Laid-Open No. 2015-20241

Therefore, the present invention was developed to eliminate the disadvantages of the prior art, and its purpose is to provide a composite particle that can realize mirror polishing using flow processing, can be used for a long time, and has less performance degradation over time, and a polishing method using the same. Material and its manufacturing method.

The present invention relates to a composite particle characterized by comprising a plurality of particles containing a material having a New Mohs hardness of 13 or more, and a resin containing polyvinyl alcohol. Furthermore, the composite particles preferably contain 95 wt% or less of particles and at least 5 wt% or more of resin.

In addition, a material having a New Mohs hardness of 13 or more is preferably silicon carbide, and its resin preferably contains an elastomer. The elastomer is a thermosetting elastomer, and its resin preferably contains a thermosetting resin.

The present invention relates to an abrasive material, which includes the composite particles as abrasive particles, and the average particle diameter of the composite particles is preferably 0.1 mmΦ~3.0 mmΦ.

In addition, the present invention relates to a method for manufacturing composite particles, which is characterized by It consists of a first step, dispersing a powder containing a material with a new Mohs hardness of 13 or more in an aqueous solution containing polyvinyl alcohol and an alkali metal salt of alginic acid; the second step is to make the powder obtained through the first step The dispersion liquid is contacted with the aqueous solution containing the cation-containing compound; and the third step is to dry the formed product obtained by the second step.

If the composite particles of the present invention are used as abrasive grains for abrasives, the cutting force and abrasive force of the particles exposed on the surface of the composite particles and the elasticity of the resin constituting the composite particles can be used to make it impossible to pass through high-hardness silicon carbide powder. To achieve the use of flow processing mirror polishing.

In addition, when the composite particles of the present invention contact the object to be treated as abrasive particles, the particles exposed on the surface are worn away, and the polyvinyl alcohol-containing resin gradually wears down from the surface. Therefore, even if the most surface particles are consumed, New particles appear from below, so there is little degradation in performance as an abrasive, and a longer life can be achieved.

1: Resin containing PVA

2: Particles containing materials with a new Mohs hardness of 13 or more

3: Composite particles

4: Object to be processed

M: Motor

Fig. 1 is a schematic diagram of the composite particle of the present invention.

FIG. 2 is a schematic diagram of the device used in Example 1. FIG.

FIG. 3 is a schematic diagram of the device used in Example 3. FIG.

Fig. 4 is a schematic diagram of a polishing test device used in Examples and Comparative Examples.

Hereinafter, an embodiment of the present invention will be described in detail, but the present invention It is not limited in any way by this embodiment.

The present invention includes a plurality of particles including a material having a new Mohs hardness of 13 or more, and a resin containing polyvinyl alcohol (PVA), and the plurality of particles includes a material having a new Mohs hardness of 13 or more.

In this way, if a relatively high hardness material with a new Mohs hardness of 13 or more is used, when it is combined with a resin containing PVA, the necessary abrasive force can be obtained. On the other hand, when a material with a new Mohs hardness of 12 or less is used, the polishing force is reduced, and therefore, sufficient polishing processing cannot be performed.

Examples of materials having a New Mohs hardness of 13 or more include silicon carbide, boron carbide, diamond, and the like. Among them, silicon carbide is low in price and preferable. In addition, the particle shape is preferably a crushed shape in a pulverized state, and an indefinite shape with sharp edges. The reason is that such particles are easy to obtain, and by having edges of the particles, an appropriate abrasive force can be obtained.

FIG. 1 is a diagram showing the outline of the composite particle of the present invention, including a resin 1 containing PVA and a particle 2 containing a material having a new Mohs hardness of 13 or more.

In addition, the particle diameter of the particles constituting the present invention is preferably 0.01% to 10% of the particle diameter of the final composite particle, and more preferably 0.1% to 1%. The reason is that if the particle size of the particles is too large with respect to the particle size of the final composite particles, sufficient elasticity may not be obtained and the object to be processed may be damaged. In addition, even if it is too small, sufficient grinding power cannot be obtained.

The ratio of the particles constituting the composite particles is not particularly limited, and can be changed according to the use and purpose. However, since a certain degree of elasticity is required, the proportion of particles is preferably at most 95 wt% or less, and more preferably 90 wt% or less.

In addition, in order to express the abrasive power, the particles constituting the composite particles are required, which is excellent It is selected to contain at least 10 wt% or more, and more preferably 20 wt% or more. In the present invention, even when the proportion of particles is reduced and the particles exposed to the surface are reduced, although the polishing force is adjusted, the life as an abrasive is not immediately shortened.

The present invention includes a resin containing PVA. By containing PVA in the resin, it can be used as a composite particle that is most suitable for mirror polishing using flow processing and can be repeatedly used for a long time.

In the prior art, by carrying abrasive grains on the surface of an elastomer or dispersing abrasive grains in the elastomer, it is also possible to adjust the abrasive force of the abrasive and realize mirror polishing using flow processing. However, any abrasive material has the following Disadvantages: If the abrasive grains on the surface are worn away, the performance will decrease and the service life will not be sufficient.

In contrast, in the present invention, the problem is solved by including PVA in the resin. That is, when the present invention is used as abrasive particles, the particles on the surface are worn away, and the resin containing PVA is also gradually abraded from the surface, so the particles initially buried in the resin appear on the surface with repeated use. It can achieve long life as an abrasive material.

Therefore, if the composite particles of the present invention are used as abrasive grains of an abrasive, there is little performance degradation caused by repeated use, and therefore the processing conditions can be easily determined. In addition, not only the particles exposed on the surface but also the particles inside are used, so it has the advantages of long life and saving.

The average degree of polymerization of the PVA used in the present invention is preferably 300 or more, and particularly more preferably 500 or more. The degree of saponification is preferably 70 mol% or more, particularly more preferably 90 mol% or more.

In addition, in order to modify the resin constituting the present invention, other components may be added. For example, in order to adjust elasticity, etc., an elastomer may be added. Among them, thermal hardening is preferred Chemical elastomers include, for example, natural rubber, acrylonitrile·butadiene copolymer, acrylate·butadiene copolymer, styrene·butadiene copolymer, acrylic·urethane copolymer, etc.

Furthermore, acrylic resin or phenol resin of thermosetting resin, melamine resin, epoxy resin, urethane resin, urea resin, etc. can also be added.

In order to adjust the physical properties of the composite resin of the present invention, these components may be selected in accordance with the material of the object to be processed, etc., but a plurality of components may be added.

The resin constituting the present invention preferably has a ratio of at least 5 wt% or more, and more preferably 10 wt% or more. In addition, it is preferably contained at most at a ratio of 90% by weight or less, and more preferably 80% by weight or less.

Furthermore, it is preferable that 60 wt% or more of the entire resin constituting the composite resin is PVA, and more preferably 80 wt% or more. The reason is that if the content of PVA is too small, the resin is too easy to be thinned, or it is difficult to be thinned due to the additive components, and therefore the performance as an abrasive material is deteriorated or the life is shortened.

The shape of the composite particles of the present invention is preferably substantially spherical without edges or the like as a whole, and is suitable for jet milling or flow processing.

The composite particles of the present invention can be used as abrasive grains, and their aggregates can be used as abrasives. The abrasive may contain media such as water, oil, and polymer materials.

At this time, the average particle diameter of the composite particles used as abrasive grains is preferably 0.1 mmΦ to 3.0 mmΦ, and more preferably 0.3 mmΦ to 2.0 mmΦ. The average particle diameter of the composite particles can be changed as needed, but if it is in the above numerical range, it is easy to produce relatively uniform, substantially spherical particles, which is preferable.

The composite particles of the present invention are manufactured through the following steps, which include the first step of dispersing a powder containing a material with a new Mohs hardness of 13 or more in In an aqueous solution containing polyvinyl alcohol and an alkali metal salt of alginic acid; in the second step, the dispersion obtained in the first step is brought into contact with an aqueous solution containing a cation-containing compound; and in the third step, in the second step The obtained molded product is dried.

Here, as the alkali metal salt of alginic acid, sodium alginate is preferred, and as the cation, alkaline earth metal ions such as magnesium ion and calcium ion are preferred. In addition, as the cation-containing compound, calcium chloride is preferred.

In the first step of the production method of the present invention, first, an aqueous solution of an alkali metal salt of alginic acid and a resin containing PVA is prepared. The concentration of the PVA-containing resin at this time may be freely determined in accordance with the strength or elasticity of the target composite particles. However, low resin concentration becomes advantageous in terms of raw material cost and productivity. In addition, the concentration of the alkali metal salt of alginic acid is preferably adjusted so that it becomes 0.5 wt% to 2.0 wt% with respect to the mixed aqueous solution.

Next, a powder containing a material having a New Mohs hardness of 13 or more is dispersed in the prepared mixed aqueous solution to prepare a raw material dispersion. At this time, the content ratio of the powder (abrasive grain ratio: the weight ratio of the powder containing the alkali metal salt of alginic acid and the resin component containing PVA) can be freely determined according to the grinding force of the target composite particles. The higher the powder content, the higher the grinding force and cutting force.

Then, in the second step, the raw material dispersion liquid is brought into contact with an aqueous solution containing a cation-containing compound. At this time, the concentration of the cation-containing compound is preferably 0.5 mol/l to 2.0 mol/l. By the contact method at this time, the particle size or shape of the composite particles can be controlled.

In order to make the composite particles substantially spherical, the following method can be used. For example, the method is as follows: drop the raw material dispersion from a tubular die, or spray from a spray die, or spread from the outer circumference of a disk-shaped rotating body, thereby generating droplets of the raw material dispersion, and making it Contact with an aqueous solution containing a cation-containing compound. If so In this way, roughly spherical composite particles can be produced. In addition, the particle size of the composite particles can be changed by adjusting the diameter of the die, the spray pressure, the rotation speed of the rotating body, the amount of dripping, and the viscosity of the solution.

In the method of dispersing the raw material dispersion from the outer periphery of the disk-shaped rotating body, the particle size can be reduced by increasing the rotation speed of the disk. However, if the particle size is to be 0.3mmΦ or less, the shape will easily collapse. It becomes more remarkable in the case of 0.1mmΦ or less.

In addition, the method of dropping the raw material dispersion liquid from the tubular die is easy to produce composite particles with a relatively large particle size, but if the particle size is to be 2.0mmΦ or more, the shape will easily collapse, and it will become less than 3.0mmΦ. More significant.

When used as abrasive particles, the collapse of such particle shapes may cause damage to the processed object. In addition, the actually manufactured composite particles must pass through a sieve to make the particle size uniform, but composite particles with collapsed shapes cannot pass through the sieve, resulting in a decrease in output.

The aqueous solution containing the cation-containing compound may be in a static state, but by stirring with a stirrer or the like, the reaction of the molded product is promoted, and the adhesion of the molded product to each other can be prevented. In addition, it is preferable to use a silicone tube and a roller pump for the feed of the raw material dispersion, so that the dropping amount can be fixed, and a molded product with a relatively uniform shape can be obtained.

Finally, in the third step, the molded product obtained by contacting the raw material dispersion with the aqueous solution containing the cation-containing compound is thermally dried at 60°C or higher to shrink and thermally harden the composite of the present invention. particle.

The particle size distribution and particle size of the produced composite particles can be measured by a dry sieving test (Japanese Industrial Standards (JIS) Z 8815-1994). Here, use different sieve with pore size of 45μm~22.4mm to test The sample is sieved, the mass of the sample remaining on each sieve is measured, and the particle size distribution is obtained. In addition, in this specification, the cumulative distribution is described in the graph, and the particle size at the point where the cumulative value becomes 50% is defined as the average particle size.

[Example]

Hereinafter, embodiments of the present invention will be described in detail.

<Example 1>

In Example 1, first, PVA (the degree of polymerization is 1700, the degree of saponification is 99 mol%) was added to water and stirred, and then treated at 95° C. for 2 hours or more to obtain a PVA aqueous solution. In addition, sodium alginate was added to the water and stirred until it became transparent to obtain a sodium alginate aqueous solution.

Then, the sodium alginate aqueous solution was added to the PVA aqueous solution and stirred, and a mixed solution was prepared so that the concentration of PVA became 10.0% by weight and the concentration of sodium alginate became 2.0% by weight.

In addition, GC#3000 (average particle size: 4 μm) silicon carbide powder was added to the mixed aqueous solution and stirred to obtain a raw material dispersion. At this time, the ratio of silicon carbide was 85.0 wt% with respect to the total weight of silicon carbide, PVA, and sodium alginate.

Then, as shown in Figure 2, M is a motor for rotating a stirrer and a disc-shaped workpiece (processed object). A roller pump equipped with a silicone tube with a 0.8mmΦ die opening at the front end is used. The obtained raw material dispersion was transported at 3 ml/min, and was dropped to the center of the upper surface of a Φ80 mm disc-shaped rotating body rotating at 800 rpm. The dropped raw material dispersion was spread from the outer periphery of the disk-shaped rotating body, and was brought into contact with an aqueous calcium chloride solution with a concentration of 1.0 mol/l that was stirred with a stirrer.

The raw material dispersion in contact with the calcium chloride aqueous solution becomes roughly spherical shaped 物 and sedimentation. This molded product was separated from the calcium chloride aqueous solution and washed with water. At this time, it was passed through a sieve with a hole diameter of 3 mm to remove the molded product that collapsed and became a continuous droplet shape.

Then, the obtained molded product was dried at 60°C. As a result, composite particles having an average particle diameter of 0.6 mm were obtained by thermal hardening and shrinking. Through this operation, the finally obtained composite particles became 54 g, and the yield was 92%.

The produced aggregates of composite particles were used as abrasive grains of the abrasive material, and a flow polishing test was performed. Here, fluid grinding in a liquid considered suitable for grinding of relatively soft materials is performed.

In the flow polishing test, as shown in FIG. 4, first, an aluminum plate with a diameter of 5 cm is prepared as the to-be-processed object 4, and it is attached to the tip of a stainless steel rod with a diameter of 8 mm. Next, 100 ml of composite particles of 200 ml of water and abrasive material were added to a 500 ml beaker, and the aluminum plate was rotated at 800 rpm for 1 hour to polish the surface of the plate.

In addition, the polishing performance was evaluated by measuring the surface roughness Ra and gloss before and after the treatment. Here, SV-3100 manufactured by Mitutoyo Co., Ltd. was used to measure the arithmetic average surface roughness Ra in accordance with the surface roughness specification of JIS B 0601:1994. In addition, MULTI GLOSS 268 manufactured by Konica Minolta (Co., Ltd.) was used to measure the specular gloss at a measurement angle of 60° in accordance with the specular gloss measurement method of JIS Z 8741:1997.

As a result of the flow polishing test of Example 1, the surface roughness Ra before the treatment was approximately 0.20 μm, and the surface roughness Ra after the treatment was approximately 0.03 μm or less. In addition, in the measurement of the gloss with a gloss meter, it was about 200 before the treatment, and it was about 500 after the treatment.

In addition, Table 2 shows the results of repeated use of abrasive materials to conduct a flow polishing test.

From the above results, it can be seen that the composite particles of Example 1 can be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, performance degradation is small and the life span is long.

<Example 2>

In Example 2, the composite particles were produced in the same manner as in Example 1, except that the rotation speed of the disk-shaped rotating body was changed to 350 rpm. The average particle size of the composite particles was 1.6 mm, and the yield was 86%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 2 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, performance degradation is small and the life span is long.

<Example 3>

In Example 3, as shown in FIG. 3, the same raw material dispersion as in Example 1 was dropped from a tube-shaped die with a diameter of 0.8 mm into a calcium chloride aqueous solution with a concentration of 1.0 mol/l. The raw material dispersion liquid contacted with the calcium chloride aqueous solution becomes a substantially spherical shaped product and precipitates. This molded product was separated from the calcium chloride aqueous solution and washed with water. At this time, a sieve with a hole diameter of 5 mm was passed through to remove a molded product that collapsed and became a continuous droplet shape.

Then, as a result of drying the obtained molded product at 60° C., composite particles having an average particle diameter of 2.5 mm were obtained, and the yield was 70%. In addition, as a result of visual observation of the produced composite particles, compared with Example 1 and Example 2, Saw many particles with collapsed shapes.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 3 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, performance degradation is small and the life span is long.

<Example 4>

In Example 4, composite particles were produced in the same manner as in Example 3 except that a tubular die with a diameter of 1.2 mm was used. The average particle size of the composite particles is 3.5 mm, and the yield is 60%. In addition, as a result of visual observation of the produced composite particles, compared with Example 1, Example 2, and Example 3, many particles with collapsed shapes were seen.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 4 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, performance degradation is small and the life is long.

<Example 5>

In Example 5, composite particles were produced in the same manner as in Example 1, except that the rotation speed of the disk-shaped rotating body was changed to 1200 rpm. The average particle size of the composite particles is 0.3 mm, and the yield is 80%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 5 can also be used as In addition, even if the abrasive grains of this abrasive are repeatedly used, there is little performance degradation and a long life.

<Example 6>

In Example 6, the composite particles were produced in the same manner as in Example 1, except that the rotation speed of the disk-shaped rotating body was changed to 2000 rpm. The average particle size of the composite particles is 0.2 mm, and the yield is 75%. In addition, as a result of observing the produced composite particles with a magnifying glass, compared with Example 1, Example 2, and Example 5, many particles with collapsed shapes were seen.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 6 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, performance degradation is small and the life is long.

<Example 7>

In Example 7, the composite particles were produced in the same manner as in Example 1, except that the rotation speed of the disk-shaped rotating body was changed to 2500 rpm. The average particle size of the composite particles is 0.1 mm, and the yield is 65%. In addition, as a result of observing the produced composite particles with a magnifying glass, compared with Example 1, Example 2, Example 5, and Example 6, many particles with collapsed shapes were seen.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 7 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, performance degradation is small and the life span is long.

<Example 8>

In Example 8, the ratios of silicon carbide, PVA, and alginic acid were changed as shown in Table 1, and composite particles were produced in the same manner as in Example 1. The average particle size of the composite particles was 0.7 mm, and the yield was 89%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 8 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, there is little performance degradation and a long life.

<Example 9>

In Example 9, the ratios of silicon carbide, PVA, and alginic acid were changed as shown in Table 1, and composite particles were produced in the same manner as in Example 1. The average particle size of the composite particles is 0.7 mm, and the yield is 85%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 9 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, performance degradation is small and the life span is long.

<Example 10>

In Example 10, acrylonitrile·butadiene-based latex with a solid content of 40% was further added to the mixed aqueous solution of the PVA aqueous solution and the sodium alginate aqueous solution, and the silicon carbide, PVA, and alginic acid were adjusted as shown in Table 1. Except for the ratio of acrylonitrile to butadiene rubber, composite particles were produced in the same manner as in Example 1. The average particle size of the composite particles was 0.7 mm, and the yield was 86%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 10 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, there is little performance degradation and a long life.

<Example 11>

In Example 11, a phenol resin solution was further added to the mixed aqueous solution of the PVA aqueous solution and the sodium alginate aqueous solution, and the ratios of silicon carbide, PVA, alginic acid, and phenol resin were adjusted as shown in Table 1. In addition, The composite particles were produced in the same manner as in Example 1. The average particle size of the composite particles is 0.7 mm, and the yield is 85%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 11 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, there is little performance degradation and a long life.

<Example 12>

In Example 12, an acrylonitrile·butadiene-based latex and acrylic resin solution with a solid content of 40% was further added to the mixed aqueous solution of the PVA aqueous solution and the sodium alginate aqueous solution, and the silicon carbide, Except for the ratios of PVA, alginic acid, acrylic resin, and acrylonitrile·butadiene rubber, composite particles were produced in the same manner as in Example 1. The average particle size of the composite particles is 0.7 mm, and the yield is 85%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 12 can also be used as abrasive particles that can realize mirror polishing by flow processing. In addition, even if the abrasive particles of the abrasive material are repeatedly used, performance degradation is small and the life is long.

<Example 13>

In Example 13, except for adding GC#3000 (average particle size of 4μm) boron carbide powder instead of GC#3000 (average particle size of 4μm) silicon carbide powder, the composite was produced in the same manner as in Example 1. particle. The average particle size of the composite particles is 0.7 mm, and the yield is 85%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 13 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, performance degradation is small and the life span is long.

<Example 14>

In Example 14, the composite particles were produced in the same manner as in Example 1, except that GC#3000 (average particle size: 4μm) diamond powder was added instead of GC#3000 (average particle size: 4μm) silicon carbide powder. . The average particle size of the composite particles is 0.7 mm, and the yield is 85%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Example 14 can also be used as abrasive grains that can realize mirror polishing by flow processing. In addition, even if the abrasive grains of the abrasive material are repeatedly used, performance degradation is small and the life span is long.

Hereinafter, a comparative example will be described.

<Comparative Example 1>

In Comparative Example 1, except for adding GC#3000 (average particle size of 4μm) alumina powder instead of GC#3000 (average particle size of 4μm) silicon carbide powder, the composite was produced in the same way as in Example 1. particle. The average particle size of the composite particles is 0.7 mm, and the yield is 80%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can be seen that the composite particles of Comparative Example 1 cannot be mirror-polished by flow processing, and cannot be used as a polishing material for mirror-polishing.

<Comparative Example 2>

In Comparative Example 2, composite particles were produced in the same manner as in Example 1, except that a phenol resin was used instead of PVA. The average particle size of the composite particles is 0.6 mm, and the yield is 85%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can also be seen that the composite particles of Comparative Example 2 can also be subjected to mirror polishing by flow processing, but the polishing performance is reduced compared to the case of using PVA, and the performance degradation caused by repeated use is large.

<Comparative Example 3>

In Comparative Example 3, composite particles were produced in the same manner as in Example 1, except that a melamine resin was used instead of PVA. The average particle size of the composite particles is 0.6 mm, and the yield is 85%.

Table 2 shows the result of performing the same flow polishing test as in Example 1 using the produced aggregate of composite particles as the abrasive grains of the abrasive.

It can also be seen that the composite particles of Comparative Example 3 can also be subjected to mirror polishing by flow processing, but the polishing performance is reduced compared to the case of using PVA, and the performance degradation caused by repeated use is large.

If the composite particles in the above Example 1 to Example 14 and Comparative Example 1 to Comparative Example 3 are summarized, they are as shown in Table 1 below. In addition, if the results of the flow grinding test are summarized, they are as shown in the following table. 2.

1: Resin containing PVA

2: Particles containing materials with a new Mohs hardness of 13 or more

Claims (1)

A method for manufacturing composite particles, which is characterized in that it comprises a first step of dispersing a powder containing a material with a New Mohs hardness of 13 or more in an aqueous solution containing polyvinyl alcohol and an alkali metal salt of alginic acid; and the second step , Contacting the dispersion liquid obtained in the first step with an aqueous solution containing a cation-containing compound; and in the third step, drying the formed product obtained in the second step.

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