JP2007223004A - Resinoid grinding wheel manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a resinoid grinding wheel, of which abrasive grains are fixed by a phenol resin binder and which has cavities in the structure thereof, is evened in size and distribution of cavities, and has good grinding performance improved in mechanical strength. <P>SOLUTION: In this manufacturing method of the resinoid grinding wheel, of which abrasive grains are fixed by the phenol resin binder and which has cavities in the structure thereof, the abrasive grains, the phenol resin binder, water and a forming agent are evenly mixed. A reinforcing agent is added, and a hardening agent is added and mixed evenly, thereafter, the obtained fluid mixture is run into a predetermined die, and primarily hardened by action of the hardening agent. At that time, bubbles are formed in the fluid mixture by a chemical reaction of the foaming agent, and moisture is eliminated from the obtained hardened body for drying. The hardening element after drying is further heated and secondarily hardened by action of the reinforcing agent. The bubbles formed by the reaction of the foaming agent become bubbles in the structure of the grinding wheel. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a resinoid grindstone.

  Grinding and polishing wheels can be broadly classified into vitrified wheels, resinoid wheels, metal wheels, and electrodeposition wheels depending on the type of binder used. Of these, resinoid grindstones are often used because they are sharp and easy to use in high-efficiency grinding. Generally, organic binders used in resinoid grinding wheels include phenolic resins, epoxy resins, PVA, and other organic resins such as urethane resins and melamine resins, but they have excellent durability and heat resistance. Therefore, phenol resin is mainly used.

  A resinoid grindstone using a phenolic resin as a binder is generally produced by filling a predetermined mold with a material mixture and press-molding it. The powdery phenol resin can be coated on the abrasive grains and filled in a dry state, or it can be produced by so-called casting by adding abrasive grains to a liquid phenol resin to form a liquid mixture.

  In the manufacture of a grindstone, in order to improve the sharpness at the time of grinding, that is, the grindability, it is required to increase the porosity of the grindstone. Grinding tips generated during grinding are trapped in the pores of the grindstone, so if you ensure a large proportion of pores in the grindstone, the contact area between the grindstone and the work material is large or difficult to cut Even in the case of a grinding process in which clogging is likely to occur, clogging is suitably prevented and grindability is improved.

  However, according to the above-mentioned pressure molding, which is a general method for producing a grindstone, the porosity of a resinotite grindstone using a phenol resin as a binder is about 50%, and it is matured if the porosity is further improved. There were problems such as large deformation and inability to maintain the shape.

  As an attempt to solve such a problem, a method for producing a phenol resin porous grindstone having a large number of pores in a structure in which abrasive grains are bonded to each other by a phenol resin binder, the abrasive grains, a phenol resin aqueous solution, a curing By stirring the fluid mixture obtained by mixing the agent and the surfactant, the abrasive grains, the aqueous phenol resin solution, the curing agent, and the surfactant are uniformly mixed, and a large number of the fluid mixture is contained in the fluid mixture. A mixing and stirring step for creating bubbles, a pouring step for pouring the fluid mixture into a predetermined mold, a curing step for curing the fluid mixture in the predetermined mold, and curing in the curing step. A method for producing a porous phenol resin grindstone comprising a drying step of drying the cured molded body to remove water from the cured molded body has been proposed (special feature). Document 1).

  According to the method disclosed in Patent Document 1, the pore creation mechanism is based on the traces of water evaporated in the drying process and by creating a large number of bubbles in the fluid mixture in the mixing and stirring process. Furthermore, the thing by the foaming action of the surfactant mixed in the fluid mixture, and the foam regulating action, etc. are mentioned.

  However, when bubbles are created by mixing and stirring, and bubbles are obtained by the foaming action and foam regulating action of the surfactant mixed in the fluid mixture, the size and distribution of pores formed in the grindstone structure is However, since it depends on the stirring conditions such as the viscosity of the fluid mixture and the strength of stirring, it is difficult to control, and the size and distribution of the pores finally formed may be less uniform.

  In addition, since a large amount of water is required to create bubbles by mixing and stirring, a large amount of water remains in the grindstone after curing, and it takes time to dry and remove it. In order to shorten the time, it is conceivable to increase the drying temperature. However, if the drying temperature is too high, there is a risk that cracks occur in the grindstone.

As a means for solving the above problems, the present inventors are a method for producing a resinoid grindstone in which abrasive grains are fixed by a phenol resin binder and have pores in the structure thereof, the abrasive grains, phenol resin, water, And the foaming agent are uniformly mixed, then the curing agent is added and mixed uniformly, the resulting fluid mixture is poured into a predetermined mold, cured by the action of the curing agent, and the cured product obtained Removing the moisture from the substrate, and drying, wherein bubbles are formed in the fluid mixture by a chemical reaction of the foaming agent and become pores in the grindstone structure after hardening. Proposed (Japanese Patent Application No. 2005-316204). According to this method, it has been found that the following effects can be obtained as compared with the prior art.
(1) Since the amount of water added to ensure pores is less than half that of the prior art, the drying time after curing can be shortened. In addition, the risk of cracks occurring in the grindstone is reduced with moisture evaporation due to drying.
(2) The amount of shrinkage of the grindstone in the drying process is reduced, thereby reducing the risk of cracks occurring in the grindstone, particularly when producing a grindstone with a high porosity.
(3) Since the pores are formed by the chemical reaction between the foaming agent and the base catalyst, the pore diameter and the amount of pores can be easily adjusted compared to the creation of pores by entrainment of air accompanying mixing and stirring. Small variation between and within production.
(4) A grindstone having a uniform pore size and distribution can be stably produced, and mechanical strength is improved as compared with a grindstone of the same composition produced by a conventional technique.
(5) Since the foaming agent foams at room temperature due to the chemical reaction of the foaming agent, there is less variation in pore creation compared to the foaming mechanism by the action of heat. In addition, since the foaming reaction proceeds rapidly, pores can be created in a short time.
(6) Since bubbles are rapidly generated at normal temperature by the foaming reaction, the fluid mixture can be rapidly cured as it is at normal temperature by the action of the curing agent after the bubbles are generated. By using the curing agent, unlike the conventional pressure molding, it is possible to stably manufacture from a small size to a large size grindstone.

  However, the phenol resin used as a binder in the above method is cured at a relatively low temperature of normal temperature to 60 ° C., so that the mechanical strength of the resin itself is low, so that the holding power of the abrasive grains is insufficient and good. There is a disadvantage that grinding performance cannot be obtained. In order to compensate for this drawback, in the method described in Japanese Patent Application No. 2005-316204, as an optional step, the cured product after drying is heated, for example, at 120 to 170 ° C., thereby adding phenol resin curing. In particular, the abrasive holding power of the resinoid grindstone may be increased. However, when an ester curable phenol resin is used, the curing is almost completed at a temperature of normal temperature to 60 ° C., so that even if a heating step at 120 to 170 ° C. is added, a great effect cannot be obtained.

Accordingly, a method for producing a resinoid grindstone having pores in a structure in which abrasive grains are fixed by a phenol resin binder, and a method for producing a grindstone having good grinding performance with improved mechanical strength is provided. desired.
WO01 / 85394 (Claim 1)

  The present invention is a method for producing a resinoid grindstone having pores in a structure in which abrasive grains are fixed by a phenol resin binder, the pores having a uniform size and distribution, and good mechanical strength. It is an object of the present invention to provide a method capable of producing a resinoid grindstone having grinding performance.

  As a result of intensive studies to solve the above problems, the present inventors, in the method described in Japanese Patent Application No. 2005-316204, use an ester curable phenol resin at a relatively low temperature of normal temperature to 60 ° C. The ester curing reaction to be cured is set as primary curing, and a step of curing by heating using a thermosetting phenol resin (for example, thermosetting resol type resin or novolac type resin) as a reinforcing agent is added as secondary curing. Thus, the present inventors have found that a resinoid grindstone having good grinding performance in which the mechanical strength of the phenol resin as a binder of the grindstone structure is improved and the holding power of the abrasive grains is improved can be obtained.

That is, the present invention is a method for producing a resinoid grindstone having pores in a structure in which abrasive grains are fixed by a phenol resin binder:
Uniformly mix abrasive, phenolic resin binder, water, and blowing agent;
Add stiffener, then add cure accelerator and mix uniformly;
The obtained fluid mixture is poured into a predetermined mold and subjected to primary curing by the action of the curing accelerator, whereby bubbles are formed in the fluid mixture by a chemical reaction of the foaming agent;
Removing the moisture from the resulting cured body and drying; and
Including further heating the cured body after drying to cause secondary curing by the action of the reinforcing agent, and bubbles formed by the reaction of the foaming agent become pores in the grindstone structure. .

  Preferably, the phenol resin binder is alkaline, the reinforcing agent is a thermosetting resol type phenol resin or a novolac type phenol resin, and the curing accelerator is an organic ester compound.

  The foaming agent is preferably powder or liquid, more preferably the foaming agent is a powder and is an azo compound and / or a hydrazide compound, and even more preferably, the foaming agent is 4,4 ′. -Oxybisbenzenesulfonyl hydrazide.

  In one aspect of the present invention, it may further include adding one or more selected from the group consisting of a base catalyst, a thixo material, a surfactant, and a filler and mixing them uniformly. Preferably, the base catalyst is an alkaline hydroxide, the thixo material is silica fine powder, and the surfactant is an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant. One of the agents.

  According to the method for producing a resinoid grindstone of the present invention, in addition to the effect of the method described in the above-mentioned Japanese Patent Application No. 2005-316204, in addition to the resinoid grindstone produced according to the conventional method, The effect of providing a resinoid grindstone with improved mechanical strength and good grinding performance can be obtained.

Hereinafter, preferred embodiments of the method for producing a resinoid grindstone of the present invention will be described.
The resinoid grindstone manufacturing method of the present invention is obtained by uniformly mixing abrasive grains, a phenol resin binder, water, and a foaming agent; adding a reinforcing agent and then adding a curing accelerator and mixing uniformly; The flowable mixture is poured into a predetermined mold, and is primarily cured by the action of the curing accelerator. At this time, bubbles are formed in the flowable mixture by a chemical reaction of the foaming agent; And dry; and
Including further heating the cured body after drying to cause secondary curing by the action of the reinforcing agent, and bubbles formed by the reaction of the foaming agent become pores in the grindstone structure. .

In the production method of the present invention, first, abrasive grains, a phenol resin binder, water, and a foaming agent are uniformly mixed.
Abrasive grains that can be used in the present invention include alumina-based abrasive grains, silicon carbide-based abrasive grains, zirconia-based abrasive grains, cerium oxide, silica, chromium oxide, CBN abrasive grains, and diamond abrasive grains. , Or a mixture of two or more. The type and combination of abrasive grains to be used are appropriately selected according to the grinding conditions and the material of the workpiece. Further, materials other than those listed above may be used without departing from the spirit of the present invention. The grain size of the abrasive can be widely used from 1 mm to submicron.

  The phenol resin binder for primary curing used in the present invention is a resol type phenol resin prepared as an aqueous solution by condensing phenols and aldehydes in water at normal pressure in the presence of a base catalyst. The resol type phenol resin is adjusted to be alkaline, but a neutral phenol resin may be used on condition that a base catalyst is added. A phenol resin binder reacts with the hardening accelerator mentioned later under alkaline conditions, and exhibits a primary hardening effect | action by ester hardening.

  Examples of phenols that can be used in the present invention include phenol, alkylphenols such as cresol, 3,5-xylenol, nonylphenol, p-tert-butylphenol, isopropenylphenol, and phenylphenol, resorcinol, catechol, hydroquinone, and fluoro. Examples thereof include polyhydric phenols such as glycine. Moreover, what consists of a mixture of phenolic compounds like cashew nut shell liquid, lignin, and tannin can also be used. These various phenols can be used alone or in admixture of two or more.

  Examples of aldehydes that can be used in the present invention include formaldehyde, paraformaldehyde, acetaldehyde, furfural, glyoxal, and the like, and these can be used alone or in admixture of two or more. Aldehydes should just be 1.0-5 times mole concentration with respect to phenols, Preferably, it is 1.0-3.0 times mole concentration, More preferably, 1.5-2. The concentration is 5 times molar. If the concentration of aldehydes is less than 1.0-fold mol with respect to phenols, sufficient strength will not be exhibited after crosslinking. Conversely, if it exceeds 5.0-fold mol, there is a concern about deterioration of the working environment due to unreacted aldehyde, It is inconvenient.

  Examples of the base catalyst that can be used in the present invention include alkaline hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, and these can be used alone or in admixture of two or more. The base catalyst may be in a concentration of 0.01 to 2 times mol, preferably 0.02 to 1.2 times mol, more preferably 0.5 to 1. The concentration is 0-fold molar. If the concentration of the base catalyst is less than 0.01-fold mol with respect to the phenols, it takes a long time to produce the resin, which is insufficient. If it exceeds 2.0-fold mol, a large amount of curing agent is required, Moreover, it is not preferable and inconvenient in the work environment.

The phenol resin thus obtained is water-soluble, and its weight average molecular weight _Mw is 500 to 8000. The aqueous phenol resin solution is prepared so that the phenol resin component is 30 to 75% by weight. As the phenol resin, a resol type phenol resin is used. In addition, you may add a known silane coupling agent to this phenol resin aqueous solution as another additive for the adhesive improvement of an abrasive grain. As the silane coupling agent, for example, epoxy silane and aminosilane are preferable. Further, this silane coupling agent may be added in a mixing step for obtaining a fluid mixture.

  In the case of a neutral phenolic resin aqueous solution, the above base catalyst is added in order to use as a reaction catalyst for the blowing agent. In the case of an aqueous alkaline phenol solution, the above basic catalyst can be added to adjust the reaction of the blowing agent.

The foaming agent that can be used in the present invention is a liquid foaming agent or a powder foaming agent.
Examples of liquid foaming agents include dialkylazo represented by the general formula ROOC-N = N-COOR (wherein R represents a lower alkyl group having 1 to 4 carbon atoms which may be linear or branched). Dicarboxylate is mentioned. A preferred dialkyl azodicarboxylate is diisopropyl azodicarboxylate. Other dialkyl azodicarboxylates that can be used in the present invention include dimethyl azodicarboxylate, diethyl azodicarboxylate, dipropyl azodicarboxylate, ditert-butyl azodicarboxylate, and mixtures thereof. Can be mentioned.

  Examples of the powder blowing agent include azo compounds such as azodicarbonamide and azobisisobutyronitrile, p, p′-oxybisbenzenesulfonyl hydrazide, 4,4′-oxybisbenzenesulfonyl hydrazide, dinitrosopentanemethylenetetramine. And hydrazide compounds such as benzenesulfonyl hydrazide and p-toluenesulfonyl hydrazide.

  These foaming agents may be used alone or in combination of two or more depending on the purpose. Moreover, unless it deviates from the meaning of this invention, substances other than illustrated can also be used as a foaming agent.

Furthermore, in the production method of the present invention, a reinforcing agent is added, and then a curing accelerator is added and mixed uniformly.
The reinforcing agent used in the present invention is a thermosetting resol type phenol resin or a novolac type phenol resin.

The thermosetting resol-type phenol resin is a phenol resin prepared by condensing phenols and aldehydes in water at normal pressure in the presence of a base catalyst. The phenols, aldehydes and base catalysts that can be used are as already described for the phenolic resin binder for primary curing. However, the aldehyde added in the resin synthesis is 0.5 to 3 times the concentration of the phenol and is added at a lower concentration than the phenol resin for primary curing. Moreover, since the phenol resin for primary curing (ester curing) needs to cause a curing reaction at a low temperature of normal temperature to 60 ° C., there are many methylol groups (—CH ₂ OH) which are reactive groups of the curing reaction, and specifically It is necessary to add _{2 to} 3 methylol groups (—CH ₂ OH) per benzene ring, but the thermosetting resol type phenol resin as a reinforcing agent in secondary curing is 120 to 170 ° C. It is intended to be cured by heating at a high temperature, and it is not necessary to add many methylol groups as reactive groups. Specifically, one or less (for example, 0.5) per benzene ring. : Means that there is one methylol group per two benzene rings) up to two methylol groups (—CH ₂ OH) are sufficient.

  The resol type phenol resin used as a reinforcing agent for secondary curing may have one or more (up to 4) benzene rings per repeating unit, but the amount of aldehydes added is 1 per benzene ring. It is not necessary to increase the number of benzene rings, specifically, it is in the range of 0.5 to 2 moles per mole of phenol resin. Specifically, it is in the range of 1.0 to 3 times mol per mol of phenol resin.

  The novolac type phenol resin is a phenol resin synthesized using an acid as a catalyst. Unlike the resole type, since the methyleneation reaction is more likely to proceed than the methylolation reaction, it is relatively polycyclic, has fewer methylol groups than the resol type, and is often powdered at room temperature. Therefore, as will be described later, in the primary curing performed at room temperature to 60 ° C., the novolac-type phenolic resin does not participate in the curing reaction, and is only involved in the curing reaction by heating to 120-170 ° C. in the secondary curing. It will be.

  The concentration ratio between the phenolic resin for primary curing and the phenolic resin as a reinforcing agent for secondary curing is typically 10: 0.1 to 10: 3 by weight of the resin, preferably 10: 1 to 10: 2.5.

  The curing accelerator used in the present invention is an organic ester compound. As the organic ester compound, those used as curing agents for known alkaline phenol resin aqueous solutions can be used. For example, methyl formate, ethyl formate, ethyl acetate, ethyl lactate, methyl sebacate, ethylene glycol diester Carboxylic acid esters derived from monohydric or polyhydric alcohols having 1 to 10 carbon atoms such as acetate, diacetin and triacetin and organic carboxylic acids having 1 to 10 carbon atoms, or γ-butyrolactone, γ-caprolactone, δ- Lactones such as valerolactone, δ-caprolactone, β-propiolactone, ε-caprolactone, or ethylene carbonate, propylene carbonate, 4-ethyldioxolone, 4-butyldioxolone, 4,4-dimethyldioxolone Rings such as 4,5-dimethyldioxolone Alkylene carbonates, and the like. Of these, lactones such as γ-butyrolactone, γ-caprolactone, δ-valerolactone, δ-caprolactone, β-propiolactone, and ε-caprolactone are particularly preferably used for the purpose of solving the problems of odor and flammability. be able to.

In one aspect of the present invention, one or more selected from the group consisting of a base catalyst, a thixo material, a surfactant, and a filler may be further added and mixed uniformly.
The base catalyst is preferably an alkaline hydroxide.

  Examples of the thixo material include silica fine powder. The thixo is used as needed to prevent the material with high specific gravity from sinking in the aqueous solution and making the grindstone structure non-uniform when the specific gravity distribution in the raw material in the fluid mixture is large. .

  Examples of the surfactant include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant (nonionic surfactant). Preferably, the anionic surfactant or nonionic surfactant is used. It is a surfactant.

  Anionic surfactants include fatty acid salts such as sodium laurate, sodium stearate, sodium oleate, sodium lauryl sulfate, triethanolamine lauryl sulfate, ammonium lauryl sulfate, polyoxyethylene lauryl ether sodium sulfate, polyoxyethylene alkylphenyl ether Sulfate esters such as sodium sulfate, sulfonates such as sodium dodecylbenzenesulfonate, sodium alkyldiphenyl ether disulfonate, sodium alkylnaphthalene sulfonate, disodium higher alcohol phosphate monoester, sodium alkylphosphate, dialkyldithiophosphate Examples thereof include phosphate ester salts such as zinc.

  Cationic surfactants include higher alkylamine salts such as laurylamine chloride, dihydroxyethyl stearylamine, lauryltrimethylammonium chloride, oxalate of triethanolamine monostearate, stearamide ethyl diethylamine acetate, 2-heptadecenyl- Ammonium salts such as amine salts of higher fatty acids such as hydroxyethylimidazoline, amine salts of higher alkyl halides such as cetylpyridinium chloride, amine salts of higher aliphatic amides such as stearamide methylpyridinium chloride, sulfonium salts or phosphonium salts similar to these Etc.

  Examples of amphoteric surfactants include N-alkyltriglycine, dimethylalkylbetaine, N-alkyloxymethyl-N, N-diethylbetaine, alkylbetaine, N-alkyl-β-aminopropionate, alkyldi (aminoethyl) glycine Examples thereof include hydrochloride, N-alkyl taurine salt, aminoethyl imidazoline organic acid salt and the like.

  Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl naphthyl ether, polyoxyethylenated castor oil, polyoxyethylene abiethyl alcohol, polyoxyethylene alkyl thioether, polyoxyethylene Ethylene alkylamide, polyoxyethylene-polyoxypropyleneglycol, polyoxyethylene-polyoxypropyleneglycol ethylenediamine, polyoxyethylene mono fatty acid ester, polyoxyethylene difatty acid ester, polyoxyethylene propylene glycol fatty acid ester, polyoxyethylene Polyoxyethylene types such as sorbitan monofatty acid ester and polyoxyethylene sorbitan trifatty acid ester Surfactant, ethylene glycol monofatty acid ester, propylene glycol monofatty acid ester, diethylene glycol monofatty acid ester, glycerin monofatty acid ester, pentaerythritol fatty acid ester, sorbitan monofatty acid ester, sorbitan sesquifatty acid ester, sorbitan trifatty acid ester, sucrose fatty acid ester Polyesters such as esters, fatty acid monoethanolamides, fatty acid monoisopropanolamides and alkylolamide surfactants, polyoxyethylene alkylamines, N-alkylpropylenediamines, N-alkylpolyethylenepolyamines, N-alkylpolyethylenepolyaminedimethyls Examples include amine type surfactants such as sulfates, alkyl biguanides, and long chain amine oxides.

  Moreover, a filler can be added as needed. For example, cryolite, barium sulfate, potassium sulfate, calcium carbonate and the like can be mentioned, and these can be appropriately selected depending on grinding conditions and the like.

  A predetermined amount of the above materials are weighed, put into a mixer and uniformly mixed to obtain a fluid mixture. Conditions such as the mixing time can be appropriately determined in consideration of the mixer to be used, the mixing capacity, the mixed material, the speed of the foaming reaction, and the like.

In the production method of the present invention, the obtained fluid mixture is then poured into a predetermined mold and subjected to primary curing by the action of a curing accelerator.
There is no restriction | limiting in particular in the shape and dimension of a type | mold, According to the shape and dimension of the grindstone to manufacture, it can select suitably.

  The temperature for primary curing is from room temperature to 60 ° C. By the ester curing reaction with the phenol resin binder and the curing accelerator, the fluid mixture is almost fixed as a solid after about 5 minutes from pouring into the mold. The solidified mixture is preferably left for 1 to 24 hours in order to be sufficiently cured. The standing time can be appropriately determined in consideration of the type of raw material and the molding size.

  In the production method of the present invention, bubbles are formed in the fluid mixture by the chemical reaction of the foaming agent, and these bubbles become pores in the structure after the grinding stone structure is hardened. The blowing agent plays a role of forming bubbles by reacting with the base catalyst to generate gas. The foaming reaction takes place immediately and usually ends when the curing is complete. The formed bubbles are fixed in the binder tissue in a uniformly dispersed state by the action of the curing agent.

  In the production method of the present invention, moisture is then removed from the obtained cured product and dried. Since the moisture entrained as a liquid in the binder tissue is vaporized and removed to the outside of the solid by the drying process, the drying flow path is formed, or the portion where the moisture remains is hollow and small. Continuous pores are formed. These become the pores of the resinoid grindstone according to the present invention together with the pores generated by the foaming agent.

  Drying may be performed while the solid is left in the mold, or may be removed from the mold and dried. The drying temperature is typically 60 to 100 ° C, but preferably 60 to 80 ° C. The drying temperature and drying time can be appropriately determined in consideration of the dimensions of the resinoid grindstone to be manufactured.

  In the production method of the present invention, the dried cured body is then further heated and secondarily cured by the action of the reinforcing agent. By heating, the added reinforcing agent can be hardened and the abrasive grain holding power of the resinoid grindstone can be increased. The heating temperature is, for example, 120 to 170 ° C.

  The composition of the resinoid grindstone manufactured according to the manufacturing method of the present invention described above is in the following range. That is, the abrasive grain volume ratio is a minimum of 5 volume% to a maximum of 55 volume%, the pore volume ratio is from 5 volume% to 85 volume%, and the binder ratio is a value obtained by subtracting the abrasive grain volume percentage and the pore volume percentage from 100%. It is. The specific gravity of the resinoid grindstone of the present invention is in the range of 0.5 to 2.5.

  Examples of the present invention will be described below together with comparative examples. However, these examples illustrate the feasibility and usefulness of the present invention, and do not limit the present invention.

1. Production of Grinding Wheel and Measurement of Physical Properties The physical properties of the resinoid grinding wheel produced according to the production method of the present invention and the method disclosed in Japanese Patent Application No. 2005-316204 were measured according to the following procedures. In the examples and comparative examples, the composition of the grindstone was adjusted so that the abrasive grain volume ratio = 22%, the binder volume ratio = 24%, and the pore volume ratio = 54%.
1-1. Production of grinding stone (Example)
1-1-1. Raw material Abrasive grain GC # 2000 1118g
Phenolic resin: 420 g of resol type phenolic resin (nonvolatile content 45%)
(Asahi Organic Materials Co., Ltd., product number: HPR830)
Curing accelerator: γ-butyrolactone 104g
Reinforcing agent: 42g of thermosetting resol type phenol resin (non-volatile content 90%)
(Sumilite resin manufactured by Sumitomo Bakelite Co., Ltd.)
Foaming agent (Otsuka Chemical, product number: Uniform AZ90) 47g
314g of water
1-1-2. Grinding stone manufacturing procedure Phenol resin, water and foaming agent are added to the mixer and mixed uniformly, then the abrasive grains are added and mixed uniformly, then the reinforcing agent is added, and then the hardening accelerator is added to uniformly. Mixed. The obtained fluid mixture was poured into a mold having an outer diameter of 240 × thickness of 30 × a hole diameter of 36 mm and left at room temperature for 1 hour to cure while foaming. The obtained cured product was removed from the mold and heated at 60 ° C. for 24 hours to dry the moisture. Further, the temperature was raised from 60 ° C. to 150 ° C. over 2 hours and kept at 150 ° C. for 4 hours to promote the curing reaction. The composition of the obtained grindstone was: abrasive volume ratio = 22.0%, binder volume ratio = 24.1%, pore volume ratio = 53.9%, and specific gravity was 0.996.
1-2. Production of grinding wheel (comparative example)
1-2-1. Raw material Abrasive grain GC # 2000 1018g
Phenolic resin: 420 g of resol type phenolic resin (nonvolatile content 45%)
(Asahi Organic Materials Co., Ltd., product number: HPR830)
Curing accelerator: γ-butyrolactone 104g
Foaming agent (Otsuka Chemical, product number: Uniform AZ90) 22g
Surfactant: (Shin-Etsu Chemical Co., Ltd. product number: F258) 26g
229 g of water
1-2-2. Grinding stone manufacturing procedure Phenol resin, water, surfactant and foaming agent were charged into a mixer and mixed uniformly, then abrasive grains were charged and mixed uniformly, and then a curing accelerator was charged and mixed uniformly. The obtained fluid mixture was poured into a mold having an outer diameter of 240 × thickness of 30 × a hole diameter of 36 mm and left at room temperature for 1 hour to cure while foaming. The obtained cured product was removed from the mold and heated at 60 ° C. for 24 hours to dry the moisture. Further, the temperature was raised from 60 ° C. to 150 ° C. over 6 hours and kept at 150 ° C. for 2 hours to promote the curing reaction. The composition of the obtained grindstone was: abrasive volume ratio = 22.7%, binder volume ratio = 24.7%, pore volume ratio = 52.6%, and specific gravity was 1.025 1-3. Measurement of physical properties of the grindstones The physical properties of the grindstones obtained in the above Examples and Comparative Examples were measured according to the following procedures. As for the grindstone, three samples were prepared for each of the example and the comparative example, and the physical properties were average values of the three samples.
1-3-1. Bending strength A grindstone is cut into a 40 × 10 × 15 mm cuboid, and is bent at three points at a span distance of 20 mm and a load drop rate of 0.1 mm / min according to JIS R1601-2004 (bending strength test method for fine ceramics). The strength was measured.
1-3-2. Flexural modulus (dry, wet)
According to JIS R1602-2004 (bending strength test method of fine ceramics), the elastic modulus was calculated from the distortion of the grindstone measured in the bending strength test.
1-3-3. Observation of the grinding wheel structure The grinding wheel after bending strength measurement was subjected to electron microscope observation after finishing the fracture surface with a lapping machine.
1-4. Measurement Results of Grinding Wheel Properties Bending strength and flexural modulus are shown in Table 1, and the grinding wheel structure is shown in FIG. 1 (Example) and FIG. 2 (Comparative Example).

  When compared with the comparative example, the bending strength was 70% or higher and the flexural modulus was 3 times or higher. The high flexural modulus in the examples is considered to be due to the high uniformity of the pores compared to the comparative example.

Comparing the grinding wheel structures, in the example shown in FIG. 1, the pore size is 10 to 100 μm, and the pore dispersion is uniform, whereas in the comparative example shown in FIG. 2, the pore dispersion is non-uniform. It was observed that there was. In the examples, it was observed that the abrasive grains were firmly held by the binder, and in the comparative examples, abrasive grains that were thought to have been released were observed. In the examples, it was considered that the resin strength was improved by the action of the reinforcing agent, thereby holding the abrasive grains firmly. On the other hand, in the comparative example, it was considered that the strength of the binder was weak, the holding power of the abrasive grains was insufficient, and the abrasive grains were released while finishing the fracture surface with a lapping machine.
2. Polishing performance test About the resinoid grindstone manufactured according to the manufacturing method of this invention and the method disclosed by Japanese Patent Application No. 2005-316204 specification, polishing performance was evaluated, respectively.
2-1. Manufacture of grinding wheel 2-1-1. Raw materials (Example)
Abrasive grain GC # 800 1118g
Phenolic resin: 420 g of resol type phenolic resin (nonvolatile content 45%)
(Asahi Organic Materials Co., Ltd., product number: HPR830)
Curing accelerator: γ-butyrolactone 104g
Reinforcing agent: 42g of thermosetting resol type phenol resin (non-volatile content 90%)
(Sumilite resin manufactured by Sumitomo Bakelite Co., Ltd.)
Foaming agent (Otsuka Chemical, product number: Uniform AZ90) 47g
314g of water
2-1-2. Raw materials (comparative example)
Abrasive grain GC # 800 1018g
Phenolic resin: 420 g of resol type phenolic resin (nonvolatile content 45%)
(Asahi Organic Materials Co., Ltd., product number: HPR830)
Curing accelerator: γ-butyrolactone 104g
Foaming agent (Otsuka Chemical, product number: Uniform AZ90) 22g
Surfactant: (Shin-Etsu Chemical Co., Ltd. product number: F258) 26g
229 g of water
2-1-3. Grinding stone manufacturing procedure For each of the Examples and Comparative Examples, the raw materials shown in Section 2-1 were used, and the manufacturing procedures shown in Section 1-1-2 (Example) and Section 1-2-2 (Comparative Example) were used. Therefore, a resinotite whetstone was molded. Furthermore, using the grindstones of Examples and Comparative Examples, a grinding grindstone as shown in FIG. 3 was produced.

In FIG. 3, member 1 is a core material having a hole diameter of 76.2 mm that rotates in the circumferential direction during polishing, and member 2 is a porous elastic body (for example, a sponge material) provided on the outer periphery of the core material. is there. The member 3 is a reinforcing layer provided on the outer periphery of the porous elastic body. The reinforcing layer is composed of a rubber layer fixed on the outer periphery of the porous elastic body and fibers provided inside the rubber layer. The member 4 is a polishing layer made of each of the grindstones of Examples and Comparative Examples.
2-2. Polishing Performance Test Using the polishing stones of Examples and Comparative Examples, 1500 polishing materials were processed according to the following polishing conditions, and the finished surface roughnesses R _a , R _z , R of the final processed polishing materials _Max was evaluated.
2-2-1. Polishing conditions Grinding wheel dimensions: outer diameter 150 mm x length 610 mm x hole diameter 76.2 mm
Material to be polished: Glass base epoxy resin copper clad laminate
Thickness: 0.8t
Dimensions: 510mm x 410mm
Polishing machine: Seiko C &E's printed circuit board polishing machine Grinding wheel rotation speed: 1800 rpm
Oscillation: 470 cpm
Number of passes: 1 pass Abrasive feed rate: 2 m / min
Polishing pressure: 2.0A
Number of processed materials: 1500 sheets 2-2-2. Polishing test results

  The example showing the workpiece processed by the resinoid grindstone manufactured according to the present invention has a low surface roughness and a fine surface compared to the comparative example showing the workpiece processed by the prior art grindstone. . It was considered that this is because the grindstone of the present invention has a stronger holding power of the abrasive grains than the conventional grindstone, so that the falling of the abrasive grains is suppressed and the amount of abrasive grains that become cutting edges is large.

  The grindstone manufactured according to the method of the present invention can be used for rough grinding and finish polishing, and can be applied not only to cylindrical grinding and surface grinding, but also to final finishing such as lapping and honing. Can be applied to ferrous materials as work materials or polishing materials, but can also be applied to non-ferrous metals such as copper, carbide, silicon, alumina, carbide, nitride, sapphire, quartz, various glasses, other ceramic materials, etc. It is suitably used for grinding or polishing non-ferrous materials typified by hard brittle materials.

FIG. 1 is an electron micrograph of the grindstone structure of the example. FIG. 2 is an electron micrograph of a grindstone structure of a comparative example. FIG. 3 is a schematic view of a polishing grindstone used in the polishing performance test.

Explanation of symbols

1: Core material 2: Porous elastic layer 3: Reinforcing layer 4: Polishing layer

Claims (10)

A method for producing a resinoid grindstone having pores in a structure in which abrasive grains are fixed by a phenol resin binder, comprising:
Uniformly mix abrasive, phenolic resin binder, water, and blowing agent;
Add stiffener, then add cure accelerator and mix uniformly;
The obtained fluid mixture is poured into a predetermined mold and subjected to primary curing by the action of the curing accelerator, whereby bubbles are formed in the fluid mixture by a chemical reaction of the foaming agent;
Removing the moisture from the resulting cured body and drying; and
Further comprising heating the cured body after drying to cause secondary curing by the action of the reinforcing agent, and the bubbles formed by the reaction of the foaming agent become pores in the grindstone structure, Method.   The method for producing a resinoid grindstone according to claim 1, wherein the phenol resin binder is alkaline.   The method for producing a resinoid grindstone according to claim 1 or 2, wherein the reinforcing agent is a thermosetting resol type phenol resin or a novolac type phenol resin.   The method for producing a resinoid grindstone according to any one of claims 1 to 3, wherein the curing accelerator is an organic ester compound.   The said foaming agent is a manufacturing method of the resinoid grindstone of any one of Claims 1-4 which is a powder or a liquid.   The method for producing a resinoid grindstone according to claim 5, wherein the foaming agent is a powder and is an azo compound and / or a hydrazide compound.   The method for producing a resinoid grindstone according to claim 6, wherein the foaming agent is 4,4'-oxybisbenzenesulfonyl hydrazide.   Furthermore, the resinoid grindstone according to any one of claims 1 to 7, wherein at least one selected from the group consisting of a base catalyst, a thixo material, a surfactant, and a filler is added and mixed uniformly. Production method.   The manufacturing method of the resinoid grindstone of Claim 8 whose said thixo material is a silica fine powder.   The method for producing a resinoid grindstone according to claim 8 or 9, wherein the surfactant is any one of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

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