JPH01246078A - Abrasive stone and manufacturing method thereof - Google Patents

Abstract

PURPOSE:To prevent water from permeating into an abrasive stone deeply, to avoid the softening of the abrasive stone and to diminish the abrasion loss of the abrasive stone for prolong the life of the abrasive stone by making the abrasive stone contain water repellent agent at the rate of specified weight% to abrasive grains. CONSTITUTION:Mixture composed of abrasive grains and liquid binder(water for example) is compressed to for a compact. Water repellent agent(silicon oil or paraffin wax for example) is given to this compact to obtain a desired abrasive stone. In this case, the content of water repellent agent in the abrasive stone must be 0.05 through 5weight% or 1 through 3weight%, if possible, to the abrasive grains. As a result, even if polishing is done with the abrasive stone sprayed or poured water, the water will permeate to a fixed depth of the abrasive stone, but is prevented from permeating into the abrasive stone deeply by water repellent agent. For this reason the softening of the polishing stone is avoided, and the physical strength of the polishing stone is not deteriorated, and the abrasion loss of the polishing stone is diminished, which makes it possible to prolong the life of the polishing stone.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a grinding wheel suitable for precision polishing finishing materials to be polished such as hard brittle materials, metal materials, and synthetic resins. The present invention relates to a polishing whetstone that has a long polishing life and is not softened by the water even when polishing is performed while supplying water to the polishing surface.

[Prior Art] A liquid bond whetstone is a whetstone that is made by adding a small amount of liquid to abrasive grains, mixing them uniformly, putting them in a mold, and compression molding them. Widely used for precision polishing of glass, synthetic resin, etc.

Regarding this liquid bond grindstone, for example, "Tani, Kawada"
Development of high precision polishing method using liquid bond grindstone J E1 Transactions of the Japan Society of Mechanical Engineers Vol. 50 No. 471, 1986-11J
, F. Tani, Kawata, “Development of high-efficiency polishing method using liquid bond grindstone,” Production Research Vol. 37, No. 7.

1985, 7 J, "Tani, Kawada "Application of liquid bond grinding wheel to interface cutting" Proceedings of the 1985 Japan Society of Precision Machinery Autumn Conference Academic Lectures", R Tani, Kawada "High efficiency of silicon wafers using liquid bond grinding wheel""Polishing" 1985 Society for Precision Engineering Spring Conference Proceedings J, r Kawata "High efficiency and high precision polishing method using liquid bond grindstone" Journal of the Japan Society of Mechanical Engineers, Vol. 90, No. 821, 1986 4 It is listed in the 1st issue of the month.

The liquid bonded grindstone described in these documents sets the mixing ratio of abrasive grains and liquid to be between the pendular region and the funicular region, and performs mixing and compression.

This is a whetstone manufactured by manipulating molded grass.

In this case, since the mixing ratio of the liquid is small, the fluidity of the mixture is poor, and the abrasive grains and the liquid are mixed non-uniformly. Therefore, if the mixture is pressure-molded in the non-uniform mixed state, the formed liquid bond grindstone will have variations in density and hardness, and the grindstone may collapse within 1 minute during polishing.
The polishing finish is uneven. The mixing ratio of abrasive grains and liquid that is between the pendular region and the funicular region varies depending on the type of abrasive grains and liquid, the particle size and shape of the abrasive grains, etc. It is thought that it is about 10% to 20% of the total, which is extremely small.

The present applicant has proposed a liquid bond grindstone that eliminates the drawbacks of the liquid bond grindstone described in the above-mentioned document, although it is not yet publicly known.
By diluting the liquid that binds the abrasive grains with another liquid that is more volatile than this liquid, uniformly mixing an excess amount of the diluted liquid with the abrasive grains, and then removing the excess liquid,
Alternatively, the mixing ratio of the abrasive grains and the liquid can be arbitrarily set so that the conditions are convenient for mixing, compression, and molding operations, and the abrasive grains and the liquid are mixed, compression molded, and then dried. We propose a liquid bond grindstone that reaches the pendular region by reducing the liquid content, and as a polishing method that uses the liquid bond grindstone that reaches the pendular region. It is suggested that water or other liquids be added to the In the polishing method according to this proposal, since the filling form of the abrasive grains in the liquid bond grindstone reaches from the pendular region to the funicular region by adding water during polishing, it is possible to realize good precision polishing.

[Problems to be Solved by the Invention] Center cutting is performed using a conventionally known liquid bonded grindstone in which abrasive grains are bonded with a liquid so that the abrasive grains are filled between the pendulum castle and the funicular region. When carrying out processing operations,
In order to suppress the temperature rise of the polished material due to the frictional heat generated during polishing, or to remove chips that adhere to the surface of the liquid bond grindstone, water or an aqueous liquid is poured on the surface of the liquid bond grindstone. Alternatively, spraying is performed.

However, as mentioned above, when water or aqueous liquid is applied or sprayed during polishing, water infiltrates into the interior of the liquid bond grinding wheel, and as a result, the abrasive grains between the pendular region and the funicular region are The filling state rapidly becomes a capillary state or, in extreme cases, a slurry state, making polishing with a liquid bond grindstone impossible.

In addition, in the polishing method proposed by the present applicant, when polishing using a liquid bond whetstone in which the abrasive grain filling state has reached the pendulum range, water or By flowing or spraying an aqueous liquid, the filling state of the abrasive grains is changed from the pendular region to the funicular region, thereby achieving a good polishing state.

However, upon further study by the present inventors, it was found that in the polishing method proposed by the present applicant, the water added during polishing only penetrates to a very deep place from the polishing surface of the liquid bond grindstone. If not, good polishing will be achieved, but if the amount of water added to the liquid bond whetstone is not controlled during polishing, the added water will gradually penetrate deep into the liquid bond whetstone. It was found that the bonding agent was softened or liquefied, and the entire liquid bond grinding wheel was softened.

It is extremely complicated to strictly control the amount of water, etc. added to the liquid bond grindstone during polishing.

However, if you add an excessive amount of water without controlling the amount of water added, as mentioned above, the excess water will penetrate deep into the liquid bond grinding wheel, causing it to soften. , it collapses due to the pressing force during polishing, and the abrasive grains are scraped off.

If water intrudes into the liquid bond grindstone during polishing, the amount of abrasive grains worn out becomes abnormally large, shortening the life of the grindstone and eventually increasing processing costs.

As described above, in both the conventional liquid bond grindstone and the liquid bond grindstone proposed by the applicant, it is important to prevent the grindstone from softening due to water and other cooling liquids supplied to the polishing surface during polishing. It has become a challenge.

The object of the present invention is to solve the above-mentioned problems, and to provide a grinding wheel that prevents softening of the grindstone due to water or aqueous liquid supplied during polishing, or a grindstone that can be used without strictly controlling the amount of water added during polishing. It is an object of the present invention to provide a polishing wheel that does not easily soften due to water or the like even when added to the polishing wheel.Another object of the present invention is to provide a novel method for manufacturing the polishing wheel.

[Means and Functions for Solving the Problems] The invention as set forth in claim 1 for solving the above problems is such that a molded article formed by bonding abrasive grains with a liquid binder and compression molding is bonded to the abrasive grains. l)
This is a polishing whetstone characterized by containing a water repellent in a proportion of 01.05 to 5%.

The invention according to claim 2 for solving the above-mentioned XR problem is a manufacturing method of a polishing whetstone, characterized in that abrasive grains, a liquid binder, and a water repellent are mixed and compression molded. .

The IJI according to claim 3 for solving the above problem is characterized in that a mixture of abrasive grains and a liquid binder is compressed to form a molded body, and a water repellent agent of +1 is added to this molded body. This is a method for manufacturing a grinding wheel.

The abrasive grains constituting the polishing whetstone of the present invention include:

There are no particular restrictions as long as the particles have abrasive properties; for example, diamond, corundum, emery, garnet, silica, tripoli, calcined dolomite, fused alumina, artificial emery, silicon carbide, boron carbide, iron oxide, calcined alumina, chromium oxide, I can't list any of the following, including oxide, zirconium oxide, magnesium oxide, 'tRN calcium, silica, whitebait, etc.

The particle size of the abrasive grains is preferably fine powder of 30 pm. In addition,
The selection of abrasive grain size is basically based on the required finished surface roughness of the material to be polished, or the strength of the whetstone is determined by the finer the abrasive grains, the larger the abrasive grain size. Sometimes, fine abrasive grains can be mixed in to increase strength.

The liquid binder is not particularly limited as long as it can bind abrasive grains and form a molded product, such as water, an alkaline solution, an acidic solution, an aqueous solution containing other salts, or a polymer. Examples include solutions, oily liquids, magnetic fluids, and the like. Also, from a different perspective, the liquid binder may be a liquid binder containing an organic substance as an additive, or an inorganic substance as an additive (in this case, it does not contain metal).

) may be used.

Examples of the organic substances include phenolic resin, xylene resin, polyvinyl alcohol resin, acrylic resin, urethane resin, carboxymeral cellulose ((:
Examples include M(:), starch, petroleum resin, etc.

Examples of the inorganic substance include water glass and magnesium chloride.

The liquid state of the liquid binder is solution, emulsion,
Any form of suspension may be used.

As mentioned above, the liquid binder may be simply water as long as it can bind the abrasive grains, but it is usually preferable to use a liquid binder containing additives. This additive has the effect of further strongly bonding the abrasive grains to each other and significantly increasing the mechanical strength of the polishing wheel.

The content of the liquid binder in the polishing wheel is in a filling state between the abrasive grains and the pendular region and the funicular region.
Preferably, the content is within a range that provides a filling state in the granular region.

The content of the liquid binder varies depending on the type of abrasive grains, the average particle diameter of the abrasive grains, the type of liquid binder, and the type and amount of additives contained in the liquid binder. It cannot be generally specified, but it is normal.

When the content of the liquid binder is 10 to 20% by weight of the abrasive grains, it is possible to realize a filling state of the abrasive grains that is intermediate between the pendular region and the funicular region, and
If the abrasive grains are to be filled in the pendular region, the content of the liquid binder in the abrasive grains is usually 1 to 20% by weight, preferably 5 to 15% by weight of the abrasive grains.

If an additive is to be included in the liquid binder, the content of the additive in the polishing whetstone cannot be unconditionally determined as it varies depending on the abrasive grains, the type of liquid forming the liquid binder, etc. However, it is generally 1% by weight or less based on the abrasive grains.

As the water repellent, any substance that can impart water repellency can be used, such as silicone oil, silicone emulsion, water-soluble silicone, paraffin wax, natural wax, wax emulsion, and fluorine-based water repellent. Agents, etc. can be mentioned.

The content of the water repellent in the polishing whetstone is usually 0.05 to 5% by weight, preferably 1 to 3 tons, based on the abrasive grains! ,
;, %.

+iii. Containing water repellent agent 1. ) is less than 0.051<j%, the polishing whetstone will not have good water repellency;
In addition, if the content exceeds 5% by weight, the water repellency becomes too strong, and when water, etc. is added to the polished surface of the polishing wheel, water penetrates from the polished surface of the polishing wheel to a predetermined depth. I won't.

The amount of water repellent added is an important matter. This is because by containing a water repellent in the ratio in the above range, when water is added when polishing with a polishing whetstone, the wood etc. will penetrate to the specified depth from the time of polishing with the polishing whetstone. However, there is a subtle effect that prevents it from penetrating beyond that point. And, through such subtle effects,
During polishing of the cutting wheel, self-dressing is achieved without being inhibited, and water and the like do not penetrate deep into the polishing wheel, thereby preventing softening of the polishing wheel.

Note that this water repellent is also thought to have the function of binding abrasive grains in a polishing whetstone, similar to the liquid binder.

The polishing whetstone according to claim 11 can be manufactured by various methods, but it is particularly preferable to manufacture it by the methods according to claims 2 and 3.

The method according to claim 2 is characterized in that the abrasive grains, the liquid binder, and the water repellent are mixed and compression molded.

The mixing ratio of each component during mixing cannot be defined unconditionally as it varies depending on the type of each component, but generally speaking, it is determined whether the abrasive grains are abrasive grains or the ratio between the pendular region and the funicular region. It is within a content range such that it is in an intermediate filling state, preferably in a pendular region filling state.

When mixing, each component may be immediately mixed and kneaded in a proportion set so that the content falls within the above content range, but
The proportions of each component may be arbitrarily set so as to provide conditions convenient for mixing, compression, and molding operations, and then the components may be mixed.

For the mixing operation, an ordinary mixer or mixing granulator can be used.

The mixture obtained by mixing is first compressed and molded into a predetermined shape.

Compression molding can be performed using a normal compression molding machine.

The pressure required for compression molding is preferably 100 kg/cm2 or more, preferably 300 kg/cm2 or more.

In the invention according to claim 2, a mixture obtained by mixing abrasive grains, a liquid binder, and a water repellent is compression molded so that the abrasive grains in the molded body are in a filled state in the pendular region. It is preferable to subject the molded article obtained by liquid reduction treatment to reduce the liquid content. In addition, in some cases,
The liquid reduction treatment may be performed on a mixture obtained by mixing abrasive grains, a liquid binder, and a water repellent, or a mixture obtained by mixing abrasive grains, a liquid binder, and a water repellent. The liquid reduction treatment may be performed at the same time as compression molding.

For polishing wheels obtained through such processing,
The liquid contained therein is adsorbed onto the surface of the abrasive grains, resulting in a stable state in which the liquid does not easily separate from the abrasive grains. Therefore, a polishing whetstone that is filled with abrasive grains does not change its mechanical strength even when stored for a long period of time. Since the ring does not open or break easily, it can be easily transported and attached to equipment.

Examples of the liquid reduction treatment include a drying treatment using a dryer, a liquid absorption treatment in which a liquid absorbing agent is brought into contact with the liquid, and the like.

When a drying process is employed as a liquid reduction process, drying is preferably performed at 50 to 70°C for 10 hours to several tens of hours, in stages or in multiple stages, to reduce the liquid content in the polishing wheel to about 5%.
It is preferable to make it less than % by weight.

Furthermore, even when a liquid absorption process is adopted as the liquid reduction process, it is preferable to perform the liquid absorption process so that the liquid content in the polishing grindstone is within the above range.

The method according to claim 3 is characterized in that a mixture of abrasive grains and a liquid binder is compressed to form a molded body, and a water repellent is applied to this molded body.

The mixing ratio of abrasive grains and liquid binder during mixing differs depending on the type of each component and cannot be unconditionally defined, but generally speaking, it is determined that The content is in a filling state intermediate between that of the Pendular region, and preferably within the content range of the Pendular region.

When mixing, each component may be immediately mixed and kneaded in a proportion set so that the content falls within the above content range, but
The proportions of each component may be arbitrarily set so as to provide conditions convenient for mixing, compression, and molding operations, and then the components may be mixed.

The mixing operation and the compression molding operation after mixing are the same as in claim 2 above.

In addition, the liquid content is added to the molded product obtained by compression molding the mixture obtained by mixing the abrasive grains and the liquid binder so that the abrasive grains in the molded product are in a filled state in the pendular region. Preferably, a liquid reduction process is performed to reduce the amount of liquid. In addition,
In some cases, the liquid reduction treatment may be performed on a mixture obtained by mixing abrasive grains and a liquid binder,
Further, the liquid reduction treatment may be performed simultaneously with compression molding of the mixture obtained by mixing the abrasive grains and the liquid binder.

The liquid reduction process is the same as in claim 2 above.

The molded article thus obtained is subjected to a water repellent treatment in which a water repellent is applied.

The water repellent treatment is carried out by a dipping operation in which the molded body is immersed in a liquid containing a water repellent or the water repellent itself, a spraying operation in which a water repellent-containing liquid containing a water repellent or a water repellent is sprayed, etc. be able to.

The concentration of the water repellent in the liquid containing the water repellent in the dipping operation can be determined as appropriate, and the dipping time and the number of dipping times can also be determined depending on the concentration of the water repellent.

The concentration of the water repellent in the water repellent-containing liquid in the spraying operation, the spraying time, and the number of uni cycles can also be appropriately determined according to the above-mentioned dipping treatment.

Since this water repellent also has the effect of binding abrasive grains, it is desirable to remove the excess water repellent after the water repellent treatment.

The polishing whetstone according to claim 1 obtained by the method according to claims 2 and 3 has water repellency, but when water or the like is applied to this polishing whetstone, the surface of the polishing whetstone It has a unique property that trees etc. can only penetrate to a certain depth.

Therefore, when polishing a material to be polished using the polishing wheel of the present invention, if the polishing is performed while spraying or pouring water on the polishing wheel, at that time, a certain level from the surface p1 of the polishing wheel Water penetrates to the depth, but does not penetrate deep inside, which prevents the polishing whetstone from softening. Moreover,
During polishing, at the sliding part between the polishing wheel and the material to be polished,
The abrasive grains convert to a funicular state, and the self-dressing function is further promoted, resulting in a good abrasive layer state.

[Example] The present invention will be explained in detail below.

(Example 1) Alumina W cloud 1000 abrasive grains (average diameter of abrasive grains 154 m)
) 500g, solvent-type xylene resin (solid content 45!i!
%) and 1% by weight of silicone oil (methylhydrodiene polysiloxane) to the grinding wheel.
Then mixed in a mixing granulator.

The granules were granulated, placed in a mold, compressed at 180 kg/cm'' and compression-molded, and the molded product was taken out and dried at 95°C for 8 hours to obtain a grindstone for polishing. The grindstone had good water repellency with a contact angle of 110°.The obtained grindstone also had a hardness HR of 50 (according to J I 5Z2245) and a bending strength of 15, which is sufficient for polishing the material to be polished. g/cm" and a compressive strength of 10 Kg/cm".

Furthermore, using this liquid bond grindstone, silicon nitride, which is a hard and brittle material, was processed at a processing pressure of 10 kg/c while flowing water on the polishing surface.
m2 relative rotational speed 30 m/win, sliding.

When polished, the grinding rate was 1.2 gm/mi, and the amount of wear of the grinding wheel in one hour of polishing time was 2.
It was 0 mm. This indicates that self-tressing was active, that clogging of the grindstone was sufficiently suppressed, and that it was possible to polish at a high Te ratio for a long period of time.

(Example 2) A paraffin wax emulsion of 1.5 to 3.01i% based on the abrasive grains was dropped onto 1 kg of silicon carbide (SiC) C cloud 3000 abrasive grains and 250 g of acrylic emulsion as a binder, and then The mixture was mixed and granulated using a mixing granulator, put into a mold, compressed and molded at 400 kg/cm2, and the molded product was taken out and dried at 60 to 70°C for 6 hours to obtain a grindstone for polishing. . The polishing wheel thus obtained had good water repellency with a contact angle of 100°.

The obtained whetstone has a hardness of HRR90, which is sufficient for polishing the material to be polished, a bending strength of 30 g/cm", and a compressive strength of 15.
g7cm”.

Furthermore, using this liquid bond grindstone, a silicon single crystal with a diameter of 3 inches, which is a hard brittle material, was polished by sliding it at a processing load of 120 kg and a relative rotational speed of 30 m/@in while flowing water on the polishing surface. The processing efficiency was 10 g, m/inch, and the amount of wear of the processing grindstone during one hour of polishing time was 0.4 mm. This indicates that self-dressing occurred actively, clogging of the grindstone was sufficiently suppressed, and moreover, it was possible to polish with high efficiency over a long period of time.

(Example 3) 350 g of CMC solution (concentration 3%), which is a water-soluble binder without water resistance, is added to 1 kg of silicon carbide C11000 abrasive grains.
20 g of silicone (dimethylpolysiloxane) emulsion was added dropwise to the mixture and granulated. The granulated product was placed in a mold and compressed at 300 kg/cm 2 to form the product, and the molded product was taken out and dried at 50° C. for 8 hours to obtain a grindstone for polishing. The polishing wheel obtained in this way has a contact angle of 100
It had good water repellency of °. In addition, the obtained whetstone has a hardness of HR, 30, which is sufficient for polishing the material to be polished.
Bending strength: 25 Kg/cm", compressive strength: 10 Kg/c
+s”.

Furthermore, using this liquid bond grindstone, the metal material aluminum, which is a hard and brittle material, was processed at a processing pressure of 20% without running water on the polishing surface.
When sliding and polishing was carried out at a relative rotational speed of 70 m/cm and a relative rotational speed of 0 g/am'', the cutting loss rate was 160, and the amount of wear of the processing whetstone in 10 minutes of polishing time was 50 pLm. This indicates that self-dressing was active, clogging of the grindstone was sufficiently suppressed, and it was possible to polish with high efficiency over a long period of time.

[Effects of the Invention] According to the invention described in claim 1, even when polishing while spraying or pouring water, the water penetrates to a certain depth from the surface of the polishing whetstone, and the water penetrates deep inside. Since water does not penetrate up to the point, the polishing whetstone is prevented from softening or IF, and the physical strength of the whetstone is not reduced, so the amount of wear on the whetstone is reduced and its lifespan is extended, and the dressing action is actively performed. New cutting edges are constantly generated for ultra-precise centering.

Therefore, this polishing whetstone can be applied to precision polishing of glass, ceramics, cemented carbide, metal silicone, various metals, plastics, and other materials.

Furthermore, according to the invention described in claims 2 and 3, claim 1
The polishing wheel having the excellent performance described in can be manufactured by a simple operation.

Patent applicant Taiho Ichi Kogyo Co., Ltd. Agent
Patent attorney Naoki Fukuso r, continuation amendment 1-inch

Claims (3)

[Claims] (1) For polishing, characterized in that the molded product formed by bonding abrasive grains with a liquid binder and compression molding contains a water repellent at a ratio of 0.05 to 5% by weight based on the abrasive grains. Whetstone. (2) A method for manufacturing a polishing whetstone, which comprises mixing abrasive grains, a liquid binder, and a water repellent, and compression molding the mixture. (3) A method for manufacturing a polishing whetstone, which comprises compressing a mixture of abrasive grains and a liquid binder to form a molded body, and applying a water repellent to this molded body.