WO2001085394A1

WO2001085394A1 - Porous phenol resin grindstone and method for its preparation

Info

Publication number: WO2001085394A1
Application number: PCT/JP2001/003808
Authority: WO
Inventors: Akira Nagata; Osamu Kanai
Original assignee: Noritake Co., Limited; Asahi Organic Chemicals Industry Co., Ltd.
Priority date: 2000-05-10
Filing date: 2001-05-02
Publication date: 2001-11-15
Also published as: JPWO2001085394A1; AU5268101A

Abstract

A porous phenol resin grindstone (10) having a phenol resin binder (14) and abrasive grains (12) connected with one another by the resin, characterized in that the phenol resin binder (14) has a three-dimensional network structure and an extremely large number of fine through pores (16) having a diameter less than that of the abrasive grain. The grindstone (10) has a high porosity and is prone to have protrusions of abrasive grains on its abrasive surface, due to the three-dimensional network structure of the phenol resin binder, and thus exhibits excellent grinding characteristics. Further, the abrasive grain (12) being held in the phenol resin binder (14) of three-dimensional network structure having the above fine through pores (16) drops out by a relatively week force and thus is less prone to damage the surface of the material to be abraded.

Description

Description Porous phenolic resin grindstone and method for producing the same

The present invention relates to a porous resin grindstone using a phenol resin as a resin binder, that is, a phenol resin porous grindstone and a method for producing the same, and more particularly to a phenol resin porous grindstone having an increased porosity in tissue. It is. Technology background

Conventionally, whetstones that use phenolic resin as a binder to bind the abrasive grains to each other are prepared by coating powdered phenolic resin on the abrasive grains, loading the powdered phenolic resin in a prescribed state in a dry powder state, and press molding. Being manufactured.

On the other hand, in order to further improve the sharpness during grinding, that is, the grindability, it is required that the grinding wheel be made porous. Chips generated during grinding are trapped in the pores of the grindstone, so if the proportion of pores is large, clogging is likely to occur when the contact area is large or when grinding difficult-to-cut materials Since the clogging is also suitably prevented in the grinding process, the grindability is improved. However, as described above, the phenol resin porous grindstone which can be produced by press molding has a porosity of about 50% as a limit, and when trying to produce a phenol resin porous grindstone having a porosity higher than that, aging deformation occurs. There was a problem that the shape could not be maintained largely.

Also, in order to increase the porosity, a soft filler (for example, synthetic force) that does not hinder grinding may be mixed into the grindstone. In such a grindstone containing a filler, the filler acts as a pore because the filler has the retreating property at the grinding point, so high grindability can be obtained.However, even with a soft filler, There is a problem in that there is resistance, and the filler may damage the work surface. Disclosure of the invention

The present invention has been made in view of the above circumstances, and its purpose is to provide a phenolic resin porous grinding wheel having high grinding performance by increasing the porosity without mixing the filler. And a method of manufacturing the same.

The gist of the first invention for achieving the above object is a phenolic resin porous whetstone in which abrasive grains are mutually bonded by a phenolic resin binder, wherein the phenolic resin binder is three-dimensional. By having a network structure, a number of minute continuous ventilation holes having a smaller diameter than the abrasive grains are formed.

The phenolic resin porous whetstone thus configured has a high porosity because the phenolic resin binder that binds the abrasive grains has a three-dimensional network structure. High abrasiveness can be obtained because the protrusion of abrasive grains is easy to obtain. Furthermore, since the abrasive grains are held in the grindstone by a phenolic resin binder having a three-dimensional network structure innumerably forming micro communicating holes having a smaller diameter than the abrasive grains, the abrasive grains fall off with a relatively weak force. Therefore, it is difficult to damage the surface of the material to be ground.

Here, preferably, the phenolic resin porous grindstone has a large number of independent pores having a diameter sufficiently larger than that of the rescue reaming vent. The phenolic resin porous grinding wheel thus configured has a higher porosity because it has a large number of independent pores having a diameter sufficiently larger than the fine continuous pores. Since they are also trapped in independent pores, higher grindability can be obtained.

Further, a second invention for achieving the above object is an invention of a method for producing the phenolic resin porous whetstone of the first invention, and the gist of the invention is that abrasive grains are mutually interlinked by a phenolic resin binder. A method for producing a phenolic resin porous whetstone having a large number of pores in a structure formed by bonding to: (a-1) uniformly mixing and stirring abrasive grains, a phenolic resin aqueous solution, and a curing agent A mixing and stirring step of forming a fluid mixture, (b) a casting step of pouring the fluid mixture into a predetermined mold, (c) a curing step of curing the fluid mixture in the predetermined mold, (d) ) The cured molded body obtained by curing in the curing step is dried to remove moisture from the cured molded body. And the process.

In this way, in the curing step, the phenolic resin dissolved in the water of the fluid mixture poured into the predetermined mold in the pouring step is three-dimensionally cross-linked to form a rigid Erich molded article. And the phase is separated from water, and the hardened phenolic resin binds the abrasive grains as a binder, but the fluid mixture is formed by mixing the abrasive grains and the phenol resin aqueous solution in the mixing and stirring step. Because of the uniform mixing, the cured moldings have abrasive particles and water uniformly dispersed in the hardened phenolic resin binder. Then, in the drying step, water is removed from the cured molded body, and the portion becomes micro communicating pores. Thus, the phenolic resin porous whetstone manufactured in this manner has a three-dimensional mesh of phenolic resin binder. By having a structure, it has a structure in which micro communicating holes having a smaller diameter than abrasive grains are formed innumerably. Preferably, the method for producing a phenolic resin porous grindstone is the method according to the first invention. It is an invention of a method for producing a phenolic resin porous whetstone having a large number of independent pores having a diameter sufficiently larger than the minute interconnected pores, and the gist of the invention is that abrasive grains are mutually formed by a phenolic resin binder. A method for producing a phenolic resin porous whetstone having a large number of pores in a bonded structure, comprising: (a-2) abrasive grains, a phenolic resin aqueous solution, a hardener, and a surfactant By stirring the fluid mixture containing the mixing agent, the abrasive grains, the phenol resin aqueous solution, the curing agent and the surfactant are uniformly mixed, and a large number of air bubbles are created in the fluid mixture. Mixing and stirring, (b) pouring the fluid mixture into a predetermined mold, and (c) curing the fluid mixture by mixing a curing agent with the fluid mixture in the predetermined mold. And (d) drying the cured molded body obtained by curing in the curing step to remove moisture from the cured molded body. In this way, in the mixing and stirring step, the abrasive particles, the aqueous phenol resin solution, the hardener, and the fluid mixture in which the surfactant is mixed are agitated, so that the abrasive particles, the aqueous phenol resin solution, The surfactant and the surfactant are mixed uniformly, and a number of air bubbles are trapped inside the fluid mixture, resulting in the fluid mixture. Due to the foaming action and foam-regulating action of the contained surfactant, uniform air bubbles are generated and the state is maintained for a long time, so that they are poured into the mold in the pouring step and further hardened. Most of the created bubbles are maintained during the curing process. Therefore, the phenolic resin is cured in the curing step, and the phenolic resin porous grindstone obtained by removing the moisture in the cured molded body in the drying step has the fine pores in addition to the fine communication holes. It has a number of independent pores that are sufficiently larger in diameter than the continuous vents.

Preferably, the phenol resin aqueous solution is an alkaline aqueous solution, and the curing agent is an organic ester curing agent. This has the advantage that the phenolic resin in the fluid mixture can be rapidly cured at a relatively low temperature of about room temperature by the organic ester curing agent.

Preferably, the surfactant is an anionic or nonionic surfactant. When an anionic or nonionic surfactant is used as described above, the anionic or nonionic surfactant has a high foaming effect, so that there is an advantage that a grindstone having a higher porosity can be obtained. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an enlarged view of the surface of a phenolic resin porous grindstone of the present invention of the present invention.

FIG. 2 is a process chart showing a process for producing the phenolic resin porous stone of FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an enlarged view showing the surface of a phenolic resin porous grindstone 10 of the present invention. As shown in FIG. 1, the abrasive grains 12 are mutually bonded by a phenolic resin binder 14 having a network structure. Note that the phenolic resin binder 14 also has a three-dimensional network structure because the phenolic resin binder 14 has a network structure inside the phenolic resin porous grindstone 10. The space formed between the meshes of the phenolic resin binder 14 Since the communication holes are the communication holes 16 and the network structure of the phenol resin binder 14 is three-dimensionally expanded, the micro communication holes 16 are also connected to each other three-dimensionally. In addition, the independent pores 18 are sufficiently larger than the minute interconnected pores 16, and are distributed substantially uniformly in the tissue independently of each other.

The phenol resin porous grindstone 10 is manufactured, for example, according to the process shown in FIG. The aqueous phenol resin solution used in step 1 is obtained by condensing phenols and aldehydes in water at normal pressure in the presence of an alkaline catalyst such as potassium hydroxide or sodium hydroxide. In such a case, the above-mentioned alkaline catalyst is further added. The phenol resin contained in the phenol resin aqueous solution thus obtained is water-soluble, and has a weight average molecular weight Mw of 500 to 8,000.

The above phenols include, in addition to phenols, alkyl phenols such as cresol, 3,5-xylenol, nonylphenol, p-tert-butylphenol, isoprobenylphenol, phenylphenol, and the like, Polyphenols such as resorcinol, catechol, hydroquinone and phloroglysin may be used. In addition, a mixture of phenolic compounds such as power nut nut shell liquid, lignin and tannin can also be used as phenols. These various phenols can be used alone or in combination of two or more.

As the above aldehydes, for example, formaldehyde, paraformaldehyde, acetate aldehyde, furfural, dalioxal, etc. are used, and these can be used alone or in combination of two or more. The aldehyde may be in the range of 1.0 to 5 times the mole of the phenol, especially in the range of 1.0 to 3.0 times, and more preferably in the range of 1.5 to 2.5 times the mole of the phenol. More preferred. If the aldehyde is less than 1.0 times the molar amount of the phenol, sufficient strength will not be exhibited after crosslinking, and if it exceeds 5.0 times the working environment may be degraded due to unreacted aldehyde. It is.

Examples of the alkaline catalyst include, for example, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, alone or in combination of two or more. used. This alkaline catalyst is preferably used in a range of 0.01 to 2 times, more preferably in a range of 0.02 to 1.2 times, and more preferably in a range of 0.5 to 1.0 times the phenols. Good. If the amount of the alkaline catalyst is less than 0.01 times the molar amount of the phenols, it takes a long time to produce the resin, which is not sufficient.If the amount exceeds 2.0 times the molar amount, the curing agent is required in a large amount. This is because the working environment is not preferable.

The aqueous phenol resin solution is prepared so that the phenol resin component is 30 to 75% by mass. In addition, a conventionally known silane coupling agent may be added to the aqueous phenol resin solution as another additive in order to improve the adhesiveness of the abrasive grains. As the silane coupling agent, for example, an epoxy silane diaminosilane is preferable. Further, this silane coupling agent may be added in the mixing and stirring step of Step 1.

As the curing agent used in step 1, an organic ester curing agent, an acid curing agent, or the like can be used. As the organic ester curing agent, those conventionally used as a curing agent for an aqueous solution of an alkaline phenol resin can be used. For example, methyl formate, ethyl formate, ethyl acetate, ethyl lactate, methyl sebacate, ethylene Carboxylic acid esters derived from mono- or polyhydric alcohols having 1 to 10 carbon atoms, such as glycol diacetate, diacetin, and triacetin, and organic carboxylic acids having 1 to 10 carbon atoms, or abutyrolactone, a Lactones such as one strength prolactone, δ-valerolactone, 6 one strength prolactone, i3-propiolactone, ε-force prolactone, or ethylene carbonate, propylene strength one-piece, 4-ethylidene Oxolone, 4-butyldioxolone, 4,4-dimethyldioxolone, 4,5-dimethyldioxolone, etc. Jo alkylene force one port ne one bets, etc. are exemplified. Among them, for the purpose of solving odor and flammability problems, such as arptyrolactone, aprolactone, δ-valerolactone, δ-force prolactone,] 3-propiolactone, ε-force prolactone, etc. Are particularly preferably used. Examples of the acid curing agent include inorganic acids such as sulfuric acid and phosphoric acid, organic acids such as phenolsulfonic acid, p-toluenesulfonic acid, and xylenesulfonic acid, and mixtures thereof. In the mixing and stirring step of step 1, the phenol resin aqueous solution, the abrasive grains, and the curing agent are charged into a stirring mixer, and if necessary, a surfactant is also charged into the stirring mixer, and the mixture is stirred and mixed for a predetermined time. I do. When a surfactant is also mixed, the abrasive, the hardener and the surfactant are sequentially or simultaneously mixed with the aqueous phenol resin solution, but when these are sequentially mixed, the mixing order is first. May be. However, it is desirable to add the curing agent at the end of the mixing and stirring step to control the reaction, and then to stir for a predetermined time. In addition, since the mixing and stirring step only needs to obtain a fluid mixture in which the aqueous phenol resin solution, the granulated particles, the hardener, and the surfactant are mixed if necessary, the aqueous phenol resin solution is prepared in advance. In this mixing and stirring step, the water-soluble phenolic resin, water, alkali metal hydroxide, abrasive grains, hardener, and, if necessary, a surfactant are mixed in any order. A flowable mixture may be prepared. Further, a resin strength improver such as hexamine, a stabilizer such as adipic dihydrazide (AADH), a viscosity modifier such as aerosil, etc. may be appropriately mixed.

When the surfactant is not mixed in the fluid mixture, the stirring is performed with sufficient stirring intensity and time to uniformly disperse the abrasive grains 12 in the aqueous phenol resin solution. Good, but if the surfactant is mixed in the flowable mixture, the abrasive is used because the surfactant is mixed to generate uniform air bubbles in the flowable mixture. The stirring intensity and time are set to a value sufficient to uniformly disperse 12 and generate the desired amount of bubbles. The average pore diameter of the bubbles generated here is 50 m or more.

As the above-mentioned surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants (nonionic surfactants) and the like can be used, and preferably anionic surfactants or nonionic surfactants are used. Use agent. Examples of anionic surfactants include fatty acid salts such as sodium laurate, sodium stearate, and sodium oleate, sodium lauryl sulfate, triethanolamine lauryl sulfate, ammonium sulfate, sodium polyoxyethylene lauryl ether sulfate sodium phenyl ether sulfate. Sulfate Este Sodium salt, sodium dodecylbenzenesulfonate, sodium alkyldiphenylether disulfonic acid, sodium alkylnaphthalenesulfonic acid, disodium salt of higher alcohol phosphate monoester, sodium phosphate alkyl phosphate, zinc dialkyldithiophosphate Etc. can be used. Examples of the cationic surfactant include higher alkylamine salts such as laurylamine chloride, dihydroxyethylstearylamine, lauryltrimethylammonium chloride, mothates of triethanolamine monostearate, and stearamidethylethyl. Amine acetates, amine salts of higher fatty acids such as decenyl-hydroxyethyl imidazoline, etc., amine salts of higher alkyl halides such as cetyl pyridinium chloride, steaamide methyl pyridinium chloride, etc. An ammonium salt such as an amine salt of a higher aliphatic amide, a sulfonium salt or a phosphonium salt similar thereto, and the like can be used.

Examples of amphoteric surfactants include N-alkyltriglycine, dimethylalkylbetaine, N-alkyloxymethyl-N, N-getylbetaine, alkylbetaine, N-alkyl-β-aminopropionate , Alkyldi (aminoethyl) glycine hydrochloride, Ν-alkyltaurine salt, aminoethylimidazoline organic acid salt and the like. Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, poly Xyethylenealkylnaphthyl ether, polyoxyethylenated castor oil, boroxyshethylene aviethyl alcohol, polyoxyethylene alkylthioether, polyoxyethylene alkylamide, polyoxyethylene-polyoxypropylene glycol, polyoxyethylene Polyoxypropylene glycol allylene diamine, polyoxyethylene monofatty acid ester, polyoxyethylene difatty acid ester, polyoxyethylene propylene glycol fatty acid ester, polyoxyethylene sorbitan monofatty acid ester, polyoxyethylene sorbitan trifatty acid ester And other polyoxyethylene surfactants, ethylene glycol monofatty acid ester, propylene glycol monofatty acid ester, diethylene glycol monofatty acid ester Polyhydric alcohols such as ter, glycerin mono fatty acid ester, pen erythrit fatty acid ester, sorbitan mono fatty acid ester, sorbitan sesqui fatty acid ester, sorbitan tri fatty acid ester, sucrose fatty acid ester, fatty acid monoethanolamide, fatty acid monoisopropanolamide, etc. And alkylolamide surfactants, polyoxyethylene alkylamine, N-alkylpropylene diamine, N-alkyl polyethylene polyamine, N-alkyl polyethylene polyamine dimethyl sulfate, alkyl biguanide, amine such as long chain amine oxide Type surfactants can be used.

In the pouring step of the subsequent step 2, the fluid mixture sufficiently mixed and stirred in the step 1 is poured into a mold having an inner surface shape corresponding to the shape of the phenol resin porous grindstone 10.

In the subsequent step 3 of the curing step, the fluidity mixture poured into the mold is left for a predetermined period of time, or the fluidity mixture poured into the mold is heated to a predetermined temperature. The phenolic resin in the mixture is cured or crosslinked.

When the phenolic resin in the flowable mixture is cured, the flowable mixture becomes a cured molded article having the above-described inner shape. At this time, the phenol resin is hardened into a three-dimensional network shape, and the hardened phenol resin acts as a binder 14 to bind the abrasive grains 12 to each other. The mechanism by which the phenolic resin crosslinks into a three-dimensional network shape is not necessarily clear, but can be considered as follows. Note that the present invention is not limited by this mechanism.

That is, in the process of hardening the phenolic resin by the addition of a hardener, the water-soluble phenolic resin dissolved in water first loses its fluidity without being phase-separated from water (gelation). In this state, the appearance is transparent. As the reaction proceeds further, the cohesive force of the molecular chains acts and separates into a resin phase (solid phase) and an aqueous phase (solvent phase), resulting in a three-dimensional network shape. In this state, the appearance becomes opaque. The size of the three-dimensional mesh (the portion becomes the minute interconnected pores 16 when water is removed) is determined by the ratio of water-soluble phenol resin to water. The size of the mesh increases as the amount of water relative to the water-soluble phenol resin increases. By changing the ratio of the water-soluble phenolic resin to water in this way, the size of the minute interconnected pores 16 can be changed within a range of 5 or less. The diameter must be smaller than 1 and 2. This is because the phenolic resin binder 14 cannot support the abrasive grains 12 when the fine continuous air holes 16 have a larger diameter than the abrasive grains 12. When a surfactant is added, it is considered that the function of the surfactant makes the pore diameter of the micropores uniform.

When a surfactant is mixed in the fluid mixture, since the fluid mixture foamed in the mixing and stirring step contains a surfactant, the mixture is poured and cured in the process. No bubbles disappeared, and the foaming state at the end of stirring was maintained. For this reason, at the end of the stake, a large number of independent pores 18 derived from air bubbles are formed in the stake molded product as shown in FIG. Can be Since many pressures are not applied to the fluid mixture and the cured molded product obtained by curing the fluid mixture, the large number of closed pores 18 are formed in the shape of the bubbles generated in the mixing and stirring step. Have been. In order to produce a phenolic resin porous grindstone having no independent pores 18, even when a surfactant is not mixed into the fluid mixture, some bubbles are mixed due to mechanical action of stirring. However, it is not necessary to remove some of the independent pores 18 as long as the grinding performance is not adversely affected.

In the subsequent drying step 4, the cured molded body is dried to remove moisture in the cured molded body. When the moisture is removed from the hardened molded body, the water that has filled the space between the three-dimensional networks is replaced with air to form an infinite number of minute communication holes 16. It is made porous. The phenol resin porous grindstone 10 is manufactured by the above-mentioned drying step, but a heat treatment step may be provided to improve the strength, and the phenol resin porous grindstone 10 may be further heated.

Next, an embodiment of a method for manufacturing the phenol resin porous grindstone 10 will be described. The dimensions of the phenolic resin porous grindstone 10 were Φ300 × 20 × 127. First, in step 1, an alkaline phenol resin aqueous solution (HP 830 L (solid content: 48% by mass, average molecular weight: 200,000) manufactured by Asahi Organic Materials Co., Ltd.) was added by 40% by mass and an anionic surfactant was used. 5% by mass, 45% by mass of gay carbide # 3000 as abrasive, and 10% by mass of lactone ester curing agent were added to the mixer in the following order in the following order and mixed and stirred. . The mixer used was a TK homomixer manufactured by Tokushu Kagaku Kogyo Co., Ltd., and the stirring blades used were Edge Juicer bottles of the company, with a stirring rotation speed of 500 to 1500 rpm. The charging order is as follows. First, the mixture of the alkaline phenolic luster aqueous solution and the surfactant is stirred for 5 minutes to generate air bubbles. Subsequently, a predetermined amount of hexamine is added and mixed and stirred for 2 minutes. Add a predetermined amount of stabilizing agent (AAD H), mix and stir for 1 minute, then add a predetermined amount of aerosil, mix and stir for 1 minute, then add abrasive grains and mix and stir for 4 minutes. Finally, a predetermined amount of the lactone ester curing agent was added, and the mixture was further mixed and stirred for 1.5 minutes. As a result, a fluid mixture in which bubbles were uniformly dispersed was obtained.

In the following step 2, the fluid mixture obtained in the step 1 is poured into a polypropylene container having a predetermined shape to obtain a phenol resin porous grindstone 10 having a diameter of 300 30020Χ127. In 3, the fluid mixture poured into the container was left at room temperature for 12 hours to obtain a cured molded body.

In the subsequent drying step 4, the cured molded body obtained in the above step 3 is continuously heated from 60 ° C. to 60 ° C. for 48 hours, and then to 150 ° C. after 6 hours. By keeping the temperature at 150 ° C. for 1 to 2 hours, a phenol resin porous grindstone 10 having a porosity of 73% was obtained.

As Comparative Example 1, an attempt was made to manufacture a grindstone using only abrasive grains and powdered phenolic resin (resin pounds) by a conventional press molding method. During the heat treatment in C, the shrinkage increased, resulting in a porosity of 50% or less, and the shape could not be maintained.

As Comparative Example 2, a grindstone having the same porosity as the phenolic resin porous grindstone 10 of the above example and having a relatively high porosity by using a filler was produced. For the filler material, synthetic force was used, which would not interfere with grinding. The grinding test results of the phenolic resin porous grindstone 10 of the above-described example and the grindstone of Comparative Example 2 were compared. The results are shown below.

(Table 1) Whetstone structure-_

Abrasive grain rate (%) Bond rate (%) Filler rate (%) Porosity (%) Example 1 3 1 6 None 7 3

Comparative Example 2 _ 1 3 1 7 2 1 4 9

(The pound ratio is the ratio of phenolic resin.)

(Table 2) Grinding conditions

Grinding machine Double-sided surface grinder (Carrier plate diameter 5 inches)

Work material Aluminum hard disk plate

Processing time 10 minutes

Processing pressure 100 g / cm ²

Wheel rotation speed (upper wheel) 15 r. P. M. (Lower wheel) 45 r. P. M.

Grinding fluid Kanebo Co., Ltd. Berg-Iland # 3001 50-fold dilution

(Table 3) Grinding result ク Surface roughness 篡 Polishing rate Example 7 0 nmRa No scratch 3/2 m / min

Comparative Example 2 1 2 0 nmRa Scratched 1 m / min

(Note that Ra is the arithmetic average roughness.) As described above, according to the present embodiment, in the curing step (step 3), the fluidity poured into a predetermined mold in the pouring step (step 2) The phenolic resin dissolved in the water in the mixture cross-links three-dimensionally to form a cured molded body and separates from the water, and the cured phenolic resin is used as a binder 14 as abrasive particles 1 2 are connected to each other, but the above-mentioned fluid mixture is mixed in the mixing and stirring step (step 1). Since the abrasive grains 12 and the aqueous phenol resin aqueous solution are uniformly mixed, the hardened molded product contains the abrasive grains 12 and water evenly in the hardened phenol resin binder 14. Is dispersed. Then, in the drying step (step 4), moisture is removed from the cured molded body, and the portion becomes micro communicating holes 16. Thus, the phenolic resin porous grindstone 10 manufactured in this manner is Since the phenolic resin binder 14 has a three-dimensional network structure, the phenolic resin binder 14 has a structure in which micro communicating holes 16 smaller in diameter than the abrasive grains 12 are formed innumerably.

That is, the phenolic resin porous whetstone 10 of the present embodiment has a high porosity and a high calorific value because the phenolic resin binder 14 that combines the abrasive grains 12 has a three-dimensional network structure. In addition, since the abrasive grains 12 easily protrude from the grinding surface of the grindstone 10, high grindability can be obtained. Further, the abrasive grains 1 2 are held in the grindstone 10 by the phenolic resin binder 14 having a three-dimensional network structure in which the microscopic continuous air holes 16 having a smaller diameter than the abrasive grains 12 are formed innumerably. Therefore, the abrasive grains 12 fall off with a relatively weak force, so that the surface of the aluminum hard disk plate is not easily damaged.

Further, according to this embodiment, in the mixing and stirring step (step 1), the fluid mixture in which the abrasive grains 12, the aqueous alkaline phenol resin solution, the lactone ester hardener, and the anionic surfactant were mixed was stirred. As a result, the abrasive grains 12, the aqueous phenolic resin solution, the lactone ester curing agent, and the anionic surfactant are uniformly mixed, and a large number of air bubbles are entrained in the fluid mixture, causing the fluid to flow. The foaming action and foam-regulating action of the anionic surfactant contained in the ionic mixture generate uniform air bubbles and maintain the state for a long time, so that the pouring step (step 2) In the process of being poured into the mold at the time of, and in the process of being hardened in the curing step (step 3), most of the created bubbles are maintained. Therefore, the phenol resin is hardened in the curing step (step 3), and the phenol resin porous grindstone 10 obtained by removing the moisture in the cured molded body in the drying step (step 4) is obtained. Has a large number of independent pores 18 having a diameter sufficiently larger than that of the small continuous air holes 16 in addition to the small continuous air holes 16.

That is, the phenolic resin porous grinding wheel 10 of the present embodiment is the same as the fine continuous air holes 16. It has a higher porosity because it has a large number of independent pores 18 with a sufficiently large diameter, and is even higher because the chips generated during grinding are also trapped in the independent pores 18 Grindability S is obtained.

Further, according to this example, the phenol resin aqueous solution is an alkaline aqueous solution, and the curing agent is a lactone ester curing agent. Therefore, the lactone ester curing agent allows the phenol resin in the fluid mixture at room temperature. It has the advantage of being cured quickly.

Further, in this embodiment, since an anionic surfactant is used as a surfactant, there is an advantage that a grindstone having a higher porosity can be obtained by a high foaming action of the anionic surfactant.

As described above, one embodiment of the present invention has been described with reference to the drawings. However, the present invention can be implemented in another mode different from the above embodiment.

For example, in the above-described embodiment, the curing time was 12 hours, but the curing time may be about 20 minutes at room temperature. That level is sufficient to cure the fluid mixture to such a degree that it maintains a certain form. In addition, the fluid mixture may be heated in order to more securely cure the mixture in a short time. For example, curing may be performed by heating at 60 ° C. for 1 hour.

What has been described above is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist thereof.

Four

Claims

The scope of the claims

1. A phenolic resin porous whetstone in which abrasive grains are mutually bonded by a phenolic resin binder,

A phenol resin porous whetstone, characterized in that the phenol resin binder has a three-dimensional network structure so that a number of minute interconnected pores smaller in diameter than the abrasive grains are formed.

2. The phenolic resin porous grindstone according to claim 1, characterized by having a large number of independent pores having a diameter sufficiently larger than the minute interconnected pores.

3. A method for producing a phenolic resin porous whetstone having a large number of pores in a structure in which abrasive grains are mutually bonded by a phenolic resin binder,

A mixing and stirring step of uniformly mixing and stirring the abrasive grains, the aqueous phenol resin solution and the curing agent to form a fluid mixture,

A pouring step of pouring the fluid mixture into a predetermined mold,

A curing step of curing the fluid mixture in the predetermined mold,

A drying step of drying the cured molded article obtained by curing in the curing step, and removing water from the cured molded article;

A method for producing a phenolic resin porous grindstone, comprising:

4. A method for producing a phenolic resin porous whetstone having a large number of pores in a structure in which abrasive grains are mutually bonded by a phenolic resin binder,

By stirring the fluid mixture obtained by mixing the abrasive grains, the aqueous phenol resin solution, the hardener, and the surfactant, the abrasive grains, the aqueous phenol resin solution, the hardener, and the surfactant are uniformly dispersed. Mixing and agitating to create a number of bubbles in the fluid mixture;

A pouring step of pouring the fluid mixture into a predetermined mold,

A curing step of curing the fluid mixture in the predetermined mold,

A drying step of drying the cured molded article obtained by curing in the curing step, and removing water from the cured molded article; A method for producing a phenolic resin porous whetstone, comprising:

5. The method according to claim 3, wherein the aqueous phenol resin solution is an alkaline aqueous solution, and the curing agent is an organic ester curing agent.

6. The method for producing a phenolic resin porous grindstone according to claim 4, wherein the surfactant is an anionic or nonionic surfactant.