JP2008272835A - Resinoid grinding wheel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resinoid grinding wheel free from the occurrence of chipping and microcrack in grinding, in particular, a hard fragile material, using epoxy resin as binder and to provide its manufacturing method. <P>SOLUTION: This resinoid grinding wheel is manufactured by fixing abrasive grains by an epoxy resin, which is a plastic epoxy resin, preferably, an epoxy resin modified by dimer acid. Preferably, rubber hardness of the resinoid grinding wheel is, measured by a rubber hardness A scale, 50-90, its 25% compression hardness (JIS K6767) is 1.0-35.0 MPa, and its elastic modulus is 5-20%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resinotite grindstone and a method for producing the same. More specifically, the present invention does not cause chipping or microcracking particularly in polishing of hard and brittle materials, and is excellent in deburring processing of stamped metal parts and polishing of uneven thin plate-like workpieces. The present invention relates to a resinoid grindstone using an epoxy resin as a binder and ensuring a good polished surface quality, and a method for producing the same.

  The resinoid grinding wheel is a grinding wheel that is widely used because of its sharpness and high-efficiency grinding. In general, phenolic resins, epoxy resins, PVA are used as organic binders used in resinoid grinding wheels, and urethane resins, melamine resins, and the like are used as other organic resins. Among these organic binders, a resinoid grindstone using an epoxy resin is suitably used for high-efficiency grinding such as deep cutting due to effects such as good wettability between the abrasive grains and the binder. In addition, the epoxy resin can be easily cast and the resinoid grindstone using the epoxy resin is easy to manufacture.

  As a kind of epoxy resin used for a resinoid grindstone, bisphenol A type epoxy resin or bisphenol F type epoxy resin is common. This is because, for example, these epoxy resins are easily available, the use of these epoxy resins as a binder improves the hardness and heat resistance of the grindstone itself, and provides a certain degree of abrasive adhesion. It can be maintained. Resinoid grindstones using an epoxy resin are disclosed in Patent Documents 1 and 2, for example.

  On the other hand, in order to obtain a resinoid grindstone having low grinding resistance and capable of achieving a good finished surface roughness, attempts have been made to make the resinoid grindstone porous using an epoxy resin as a binder. For example, in Patent Document 3, in a resinoid grindstone using a liquid epoxy resin as an organic binder, a porosity of 40% by volume or more, and 60 to 80% by volume as required is obtained by the action of the liquid foaming agent. Yes. As a result, when the obtained grindstone is used, low grinding resistance and good finished surface roughness are achieved. This is thought to be due to the decrease in the elastic modulus of the grindstone in addition to the high porosity.

JP-A-48-77489 Japanese Patent Laid-Open No. 10-202536 JP 2004-160646 A

In recent years, the demand for grinding and polishing IT-related parts such as silicon wafers and glass processing has been increasing, and the requirements for the processing characteristics have become severe.
Workpieces in this field are not iron-based materials that are the main work of grinding and polishing in the past, but glass and ceramic materials. These materials are so-called hard materials that are difficult to process compared to iron-based materials. It is a brittle material. In the processing of hard and brittle materials with fixed abrasive tools, there is a problem that chipping and microcracks are likely to occur.

  As an example of processing of hard and brittle materials, in TFT liquid crystal glass materials, edge processing is performed with a diamond wheel of a metal bond binder, but microcracks inherent in the processing streaks tend to induce subsequent dust generation. . Since dust generation leads to panel defects due to contamination and scratches in the subsequent process, in edge processing, a finish polishing process is often added which smoothes the streak and removes or reduces microcracks.

  When the grindstone using an epoxy resin as a binder described in Patent Documents 1 and 2 is used for finish polishing of glass, the streak of the pre-processing due to good adhesion between the binder and the abrasive grains. Although it is possible to ensure the sharpness of removing the wrinkles and the durability of the grindstone, the grindstone is poor in elasticity, and it is easy to generate further chipping and microcracks due to impact on the workpiece. For this reason, in order to prevent this and ensure a fine surface roughness, the abrasive grains used in the grindstone are made finer, the grindstone is made more porous, and the depth of cut and the pressure applied to the work material are reduced. In addition, it is necessary to set and control machining conditions such as strictly controlling.

In addition, when the porous grindstone disclosed in Patent Document 3 described above is used for polishing hard brittle materials, a certain degree of improvement effect was observed, but this is not always sufficient.
Also, in the deburring process of press-punched metal parts and polishing of uneven plate-like workpieces, it is required to ensure the quality of the polished surface and the durability of the grindstone in the same way as the polishing of the hard brittle material. ing.

  Therefore, in view of the above problems, the present invention is a resinoid grindstone comprising an epoxy resin as a binder, which can provide good sharpness and durability without causing chipping or microcracking particularly in polishing of hard and brittle materials. It is another object of the present invention to provide a manufacturing method thereof.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive research. The present inventors have found that the impact force is small and that it is possible to ensure a polishing force and good durability that can remove streaks on the pre-processed surface while preventing the occurrence of chipping and microcracks, thereby completing the present invention.

  In the first resinoid grindstone of the present invention, the abrasive grains are preferably fixed with an epoxy resin, and the epoxy resin is preferably a flexible epoxy resin. The flexible epoxy resin is preferably a dimer acid-modified epoxy resin.

  In the first and second resinoid grinding wheels of the present invention, the epoxy resin preferably contains an aromatic glycidyl ether type epoxy resin up to 40% by weight based on the total weight of the epoxy resin. The aromatic glycidyl ether type epoxy resin is preferably a bisphenol A type epoxy resin or a bisphenol F type epoxy resin.

In the first and second resinoid grindstones of the present invention, the resinoid grindstone is preferably made into multi-pores by using a powder or liquid foaming agent, an inorganic or organic pore-forming agent, or a surfactant. .
In the first and second resinoid grindstones of the present invention, the resinoid grindstone has a rubber hardness of 50 to 90 as measured by a rubber hardness A scale.

The first and second resinoid grinding wheels of the present invention are characterized in that the resinoid grinding wheel has a 25% compression hardness (JIS K6767) of 1.0 to 35.0 MPa.
In the first and second resinoid grindstones of the present invention, the resinoid grindstone has a rebound resilience of 5 to 20%.

  According to the present invention, there is provided a resinoid grindstone using an epoxy resin as a binder and a method for producing the same, which do not generate chipping particularly in grinding of a hard and brittle material. Since the resinoid grindstone of the present invention uses an epoxy resin, it uses an epoxy resin that has no problem in terms of durability because the adhesion between the binder and the abrasive grains is ensured. , The grinding resistance is low and chipping does not occur. In other words, good finished surface roughness can be imparted.

Hereinafter, preferred embodiments of the resinoid grindstone and the method for producing the same of the present invention will be described.
First, a preferred embodiment of the resinoid grindstone of the present invention will be described.
In order to solve the problems of the present invention, paying attention to the physical properties of the grindstone, flexibility characteristics are required for impact reduction in the polishing process of the hard and brittle material. Since the grindstone has such characteristics, generation of chipping and microcracks can be prevented.

  Also, in addition to the good adhesion between the binder and abrasive grains, if more flexibility is provided, the grindstone can also be used for deburring of stamped metal parts and polishing of uneven thin plate-like workpieces. , Ensuring a uniform ground surface of the work piece and durability of the grinding wheel, as opposed to using a conventional grinding wheel that can quickly adapt to the work material and has no flexibility Can do.

  The resinoid grindstone of the present invention is a grindstone in which abrasive grains are fixed with an epoxy resin. The epoxy resin that can be used in the present invention is a flexible epoxy resin. By using a flexible epoxy resin, the epoxy thermosetting resin composition that is a precursor composition for producing a grindstone and the grindstone that is a cured product thereof can have sufficient flexibility. Due to this flexibility, the resinoid grindstone of the present invention can exhibit high elongation over a wide temperature range from a low temperature range to a high temperature range.

  The flexible epoxy resin is not particularly limited as long as it can exhibit flexibility even after being cured with an epoxy resin curing agent. Examples of the flexible epoxy resin that can be used include, but are not limited to, diglycidyl ether of polyethylene glycol, diglycidyl ether of polypropylene glycol, and an alkylene group having 2 to 9 carbon atoms (preferably 2 to 4 carbon atoms). Polyglycidyl ether of long-chain polyols containing polyoxyalkylene glycol and polytetramethylene ether glycol, etc .; Copolymerization of glycidyl (meth) acrylate and radical polymerizable monomers such as ethylene, vinyl acetate or (meth) acrylate Compound: (Co) polymer mainly composed of conjugated diene compound or partially hydrogenated (co) polymer of epoxidized unsaturated carbon double bond; 1 or more per molecule, preferably 2 Polyester resin having at least one epoxy group; Urethane modified epoxy resin or polycaprolactone modified epoxy resin with tan bond or polycaprolactone bond introduced; dimer acid modified epoxy resin with epoxy group introduced into the molecule of dimer acid or its derivative; NBR, CTBN, polybutadiene, acrylic rubber, etc. Rubber modified epoxy resin in which an epoxy group is introduced into the molecule of the rubber component.

  A preferred flexible epoxy resin is a dimer acid-modified epoxy resin in which an epoxy group is introduced into the molecule of dimer acid or a derivative thereof that has a large effect of imparting flexibility and is easily available. Specifically, although not limited thereto, dimer acid diglycidyl ester represented by the following chemical formula is preferable.

  In the resinoid grindstone of the present invention, an aromatic glycidyl ether type epoxy resin may be used together with the flexible epoxy resin for imparting heat resistance and / or adjusting elasticity. The aromatic glycidyl ether type epoxy resin can be used up to 40% by weight based on the total weight of the epoxy resin used. If the amount of the aromatic glycidyl ether type epoxy resin exceeds 40% by weight based on the total weight of the epoxy resin to be used, the elasticity of the grindstone is lost, which is disadvantageous because the effects of the present invention are impaired.

Aromatic glycidyl ether type epoxy resins include aromatic diglycidyl ethers, aromatic triglycidyl ethers and aromatic polyglycidyl ethers.
Representative examples of aromatic glycidyl ether type epoxy resins include, but are not limited to, aromatic diglycidyl ethers:

Bisphenol A diglycidyl ether and the following formula:

Bisphenol F diglycidyl ether. These can be suitably used in the present invention because they show good adhesion to abrasive grains and are easily available.
Examples of other aromatic diglycidyl ethers include bisphenol S diglycidyl ether, resorcinol diglycidyl ether, and diglycidyl phthalate.

  Aromatic triglycidyl ethers include triglycidyl ether of trihydroxyphenylpropane, glycidyl ether of p-aminophenol, diglycidylamine, and diglycidyl ether glycidyl ester of 4,4-bis (4-hydroxyphenylpentanoic acid). Examples of aromatic polyglycidyl ethers include tetraglycidyl ether of tetraphenylene ethane, tetraglycidyl diaminodiphenylmethane, tetraglycidyl metaxylene diamine, and cresol novolac polyglycidyl ether.

Moreover, unless the effect of this invention is impaired, epoxy resins other than those exemplified above can also be used.
Therefore, the resinoid grindstone of the present invention is characterized by having specific flexibility. The flexibility of the resinoid grindstone of the present invention is defined by the following three parameters (rubber hardness, 25% compression hardness, rebound resilience).

1. Rubber hardness The rubber hardness is measured using a rubber hardness meter (A scale).
2.25% compression hardness 25% compression hardness is measured according to the following procedure specified in JIS K6767 (foamed plastic-polyethylene test method). A conceptual diagram showing the measurement method is shown in FIG.
(1) The test grindstone 2 is installed on the lower base 3 of a suitable testing machine.
(2) With the pressure direction 4 from the top to the bottom in the vertical direction, the load measuring pressure head 1 of the test machine compresses by 25% of the initial thickness of the test grindstone 2 at a compression speed of 10 mm / min and stops. The load (N) after 20 seconds is measured.
(3) A 25% compression hardness value (MPa) is obtained from the cross-sectional area of the test grindstone 2 and the load after 20 seconds by the following equation.
25% compression hardness value (MPa) = load after 20 seconds (N) / cross-sectional area of test wheel (mm ² )
3. Rebound resilience The rebound resilience is measured according to the following procedure with reference to JIS K6255 (Rebound resilience test method for vulcanized rubber and thermoplastic rubber). A conceptual diagram showing the measurement method is shown in FIG.
(1) Prepare 1/4 inch steel balls 5 for measuring Rockwell hardness.
(2) The test grindstone 2 is installed.
(3) The steel ball 5 is dropped from the test grindstone 2 at a drop height of 200 mm.
(4) The rebound height at which the 1/4 inch steel ball 5 hits the test grindstone 2 and bounces is measured.
(5) The rebound resilience (%) is obtained from the fall height and the rebound height by the following formula.
Rebound resilience (%) = rebound height (mm) / fall height (200 mm) × 100

  In the resinoid grindstone of the present invention, the rubber hardness is preferably 50 to 90 as measured by a rubber hardness meter A scale. When the rubber hardness is less than 50, the grindstone becomes soft and the polishing power is insufficient, which is inconvenient. On the other hand, when the rubber hardness is greater than 90, the grindstone becomes hard, the flexibility is lost, and chipping and microcracks tend to occur, which is disadvantageous. In the resinoid grindstone of the present invention, the hardness is more preferably 55 to 90, and most preferably 60 to 90, as measured by a rubber hardness meter A scale.

  In the resinoid grindstone of the present invention, the resilience modulus is preferably 5 to 20%. If the impact resilience is less than 5%, the grindstone becomes soft, the pressure responsiveness to the polishing pressure becomes poor, and the sharpness is lowered, which is inconvenient. Further, it is not preferable because the pressure response when the polishing pressure is changed is deteriorated. On the other hand, if the impact resilience exceeds 20%, the grindstone becomes hard and chipping and microcracks occur, which is inconvenient.

  In the resinoid grindstone of the present invention, the 25% compression hardness (JIS K6767) is preferably 1.0 to 35 MPa. If the 25% compression hardness is less than 1.0 MPa, the grindstone becomes soft and the polishing power is insufficient, which is inconvenient. On the other hand, if the 25% compression hardness is greater than 35 MPa, the grindstone becomes hard and the pressure responsiveness to the polishing pressure is deteriorated, chipping and microcracks are generated, and the grindstone is sometimes broken, which is inconvenient. In the resinoid grindstone of the present invention, the 25% compression hardness is more preferably 1.0 to 25 MPa, still more preferably 1.5 to 20 MPa, and most preferably 2.0 to 18 MPa.

  The abrasive grains that can be used in the present invention are not limited to these, but generally, alumina-based abrasive grains, silicon carbide-based abrasive grains, zirconia-based abrasive grains, cerium oxide, silica, chromium oxide, CBN abrasive grains And at least one selected from the group of diamond abrasive grains. The combination can be appropriately selected according to conditions such as grinding and the material of the material to be ground. Moreover, unless the effect of this invention is impaired, abrasive grains other than those exemplified above can also be used.

  The grain size of the abrasive grains can be applied from F4 (third stage sieve opening 4.75 mm) defined by JIS R6001 (grain size of abrasive for grinding wheel) to less than 1 μm and a minimum grain size of 0.1 μm.

  The resinoid grindstone of the present invention may contain a filler. Examples of the filler include silica, talc, cryolite, barium sulfate, potassium sulfate, calcium carbonate and the like, which can be appropriately selected depending on grinding conditions and the like.

  Furthermore, the resinoid grindstone of the present invention may be made porous in order to enhance the effect synergistically. By increasing the amount of pores in the grindstone and making the grindstone porous, grinding resistance can be reduced and grinding burn can be prevented. The pores may be added to the precursor composition of the grindstone in a surfactant, solid (eg, foamed polystyrene, polymethylmethacrylate, rubber or plastic foam) and / or liquid (eg, diisopropyl azodicarboxylate) pore former. Can be formed. The materials of the surfactant and the pore forming agent are not particularly limited as long as the effects of the present invention are not impaired. The pores may be formed by stirring the precursor composition of the grindstone and forcibly entraining the bubbles.

  In the resinoid grindstone of the present invention, the abrasive volume ratio is 5 volume% to 55 volume%, the pore volume ratio is 5 volume% to 80 volume%, and the binder ratio is 100% to the abrasive volume ratio. It is preferable that the pore volume ratio is reduced.

Next, a preferred embodiment of the method for producing a resinoid grindstone of the present invention will be described.
First, a flexible epoxy resin and optionally an aromatic glycidyl ether type epoxy resin are prepared in a liquid state and mixed. Then, an amount of curing agent based on the epoxy equivalent of the epoxy resin is added to these mixtures and mixed until uniform. Further, if necessary, a uniform mixture is obtained by adding and mixing a filler, a surfactant, a liquid and / or a solid pore forming agent. To this mixture, abrasive grains, and if necessary, other fillers, solid pore forming agents and the like are added and stirred to obtain a uniform dispersion. Next, this dispersion is poured into an arbitrary mold and heated at 40 to 90 ° C. for about 2 to 6 hours to obtain a primary cured product. After demolding the primary cured product and further heating at 120 to 160 ° C. for about 3 to 9 hours to complete the curing reaction, a resinoid grindstone according to the present invention is obtained. In the case of using a pore forming agent, the heating process promotes the formation of a porous structure.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, these illustrate the feasibility and usefulness of this invention, and do not limit the structure of this invention.

Example 1
Production of resinoid grinding wheel of the present invention using 80% by weight of dimer acid diglycidyl ester and 20% by weight of bisphenol F diglycidyl ether, which are flexible epoxy resins, as binders. did.
Abrasive grain: GC # 220 1000 parts by weight Binder: Dimer acid diglycidyl ester liquid 372 parts by weight (manufactured by Toto Kasei Co., Ltd., product number YD-171)
93 parts by weight of bisphenol F diglycidyl ether (manufactured by Toto Kasei Co., Ltd., product number YDF-170)
Curing agent: Amine-based curing agent 59 parts by weight Filler: Aerosil (silica fine powder) 1 part by weight Surfactant: Nonionic surfactant 10 parts by weight First, a predetermined part by weight of dimer acid dimer prepared in liquid form Glycidyl ester and bisphenol F diglycidyl ether and parts by weight of a curing agent based on the epoxy equivalent were added to a stirring vessel, and then a predetermined part by weight of Aerosil was added and mixed until uniform. Next, predetermined weight parts of abrasive grains were added to the mixture and mixed until uniform. The obtained mixture was poured into a mold having a predetermined size and heated at 70 ° C. for about 4 hours to obtain a primary cured product. After demolding the primary cured product, it was further heated at 145 ° C. for about 6 hours to complete the curing reaction. The resulting cured product was finished to obtain a grindstone. The composition of the produced grindstone was 28% abrasive volume, 40% binder, and 32% pore volume based on the total volume of the grindstone.

(Example 2)
Production of resinoid grindstone of the present invention using 90% by weight of dimer acid diglycidyl ester and 10% by weight of bisphenol F diglycidyl ether, which are flexible epoxy resins, as binders The same raw materials as shown in Example 1 were used. The grindstone of the present invention was manufactured according to the procedure.
Abrasive grain: GC # 220 1000 parts by weight Binder: Dimer acid diglycidyl ester liquid 423 parts by weight (manufactured by Toto Kasei Co., Ltd., product number YD-171)
47 parts by weight of bisphenol F diglycidyl ether liquid (manufactured by Toto Kasei Co., Ltd., product number YDF-170)
Curing agent: Amine-based curing agent 53 parts by weight Filler: Aerosil (silica fine powder) 1 part by weight Surfactant: Nonionic (nonionic) surfactant 10 parts by weight The composition of the manufactured wheel is based on the total volume of the wheel The abrasive volume ratio was 26%, the binder volume ratio was 37%, and the pore volume ratio was 37%.

(Comparative Example 1)
Production of Porous Resinoid Grindstone Using Bisphenol F Diglycidyl Ether as Binder A prior art grindstone disclosed in Japanese Patent Application Laid-Open No. 2004-160646 was produced using the raw materials shown below.
Abrasive grain: GC # 1000 1000 parts by weight Binder: bisphenol F diglycidyl ether liquid 755 parts by weight (manufactured by Toto Kasei Co., Ltd., product number YDF-170)
Curing agent: amine-based curing agent 191 parts by weight Surfactant: nonionic surfactant 10 parts by weight Filler: talc 380 parts by weight Liquid blowing agent: diisopropyl azodicarboxylate 30 parts by weight First, predetermined parts by weight A liquid epoxy resin (bisphenol F diglycidyl ether), a curing agent and a surfactant were put into a stirring vessel and mixed until uniform. Next, a predetermined part by weight of talc and abrasive grains were added and mixed until uniform. Next, a predetermined part by weight of diisopropyl azodicarboxylate was added, and the mixture was further stirred until it was in a desired bubble entrainment state and mixed until uniform. The obtained mixture was poured into a casting mold and heated at 90 ° C. for 1 hour to obtain a primary cured product. After demolding the primary cured product, it was further heated at 150 ° C. for about 6 hours to complete the curing reaction. The resulting cured product was finished to obtain a grindstone. The composition of the manufactured grindstone was an abrasive grain volume ratio of 7.5%, a binder volume ratio of 22.5%, and a pore volume ratio of 70%, based on the total volume of the grindstone.

(Physical property evaluation test)
About the grindstone manufactured in Examples 1-2 and the comparative example 1, according to the following procedures, the physical-property evaluation test of rubber hardness, a resilience elastic modulus, and 25% compression hardness was done.
1. Physical property evaluation procedure 1-1. Rubber hardness Hardness was measured using a rubber hardness meter (A scale).
1-2.25% Compressive Hardness According to the following procedure specified in JIS K6767 (foamed plastic-polyethylene test method), a 25% compressive hardness value was measured. A conceptual diagram showing the measurement method is shown in FIG.
(1) The grindstones obtained in the examples and comparative examples are cut into a 127 × 35 × 85 mm rectangular parallelepiped and prepared as a test grindstone 2.
(2) A 127 × 35 mm surface of the test grindstone 2 is used as a compression surface, and is set on the lower base 3 of an autograph AG-10TD testing machine manufactured by Shimadzu Corporation.
(3) With the pressure direction 4 from the top to the bottom in the vertical direction, the load measuring pressure head 1 of the test machine compresses by 25% of the initial thickness of the test grindstone 2 at a compression speed of 10 mm / min and stops. The load (N) after 20 seconds is measured.
(4) A 25% compression hardness value (MPa) is obtained from the cross-sectional area of the test grindstone 2 and the load after 20 seconds by the following equation.
25% compression hardness (MPa) = load after 20 seconds (N) / cross-sectional area of test wheel (mm ² )
1-3. Rebound resilience The rebound resilience was measured according to the following procedure with reference to JIS K6255 (Rebound resilience test method for vulcanized rubber and thermoplastic rubber). A conceptual diagram showing the measurement method is shown in FIG.
(1) Prepare 1/4 inch steel balls 5 for measuring Rockwell hardness.
(2) The grindstones obtained in the examples and comparative examples are cut into a 127 × 35 × 85 mm rectangular parallelepiped and prepared as the test grindstone 2.
(3) The steel ball 5 is dropped from the test grindstone 2 at a drop height of 200 mm.
(4) The rebound height at which the 1/4 inch steel ball 5 hits the test grindstone 2 and bounces is measured.
(5) The rebound resilience (%) is obtained from the fall height and the rebound height by the following formula.
Rebound resilience (%) = rebound height (mm) / fall height (200 mm) × 100
2. Test Results Table 1 shows the physical property evaluation test results of the grindstones manufactured in Examples 1-2 and Comparative Example 1.

2-1. Rubber hardness value The rubber hardness was 84 in Example 1 and 75 in Example 2, which was lower than 98 in Comparative Example 1. This result shows that the grindstone of the present invention is soft.
2-2.25% Compressive Hardness 25% Compressive Hardness was 7.3 MPa in Example 1 and 4.4 MPa in Example 2, but in Comparative Example 1, the grindstone was broken and could not be measured. This result shows that the grindstone of the present invention is less brittle than the prior art grindstone of Comparative Example 1.
2-3. Rebound resilience The rebound resilience was 16% in Example 1 and 13.5% in Example 2, which was lower than the 25% in Comparative Example 1. This result shows that the grindstone of the present invention has a high ability to absorb impact or load.

(Grinding test)
A grinding test was performed using the test grindstones manufactured in Examples 1 and 2 and Comparative Example 1, and the grinding performance of the grindstone was evaluated by measuring the grinding resistance, the work material removal amount, and the finished surface roughness.
1. Grinding conditions A grinding test was performed according to the following conditions.
Grinding wheel Dimensions: Outer diameter 200mm x Thickness 15mm x Hole diameter 50.8mm
Shape: 1A type work material Material: TFT LCD glass Dimensions: Length 100mm x Width 100mm (cut out)
Grinding fluid Name: Crecat NS201
Concentration: 2%
Flow rate: 500 ml / s (30 l / min)
Grinding machine Type: horizontal axis surface grinding machine manufactured by Okamoto Engineering Model: CNC-52B (7.5kw)
Truing, dressing conditions Truer: Taishi dresser Wheel speed: 40m / s
Truing feed speed: 8.3 mm / s
Truing lead: 0.16mm / rev
Grinding conditions Grinding method: Plane plunge grinding
Wheel peripheral speed: 40 m / s
Table speed: 83.3 mm / s
Cutting depth: 0.5 μm / pass
1. Work surface roughness before grinding test: Adjust to 3.0 μm Rz JIS Test Results Grinding performance of the grindstone was evaluated by measuring grinding resistance, removal amount of work material, and finished surface roughness.
2-1. Grinding resistance Table 2 shows the results of grinding resistance.

In the grinding test using the grindstone of Comparative Example 1, the grinding resistance increased at a set depth of 100 μm and showed an abnormal value, so the subsequent grinding test was stopped. As a result, although the grindstone of Comparative Example 1 is a porous grindstone, since a non-flexible epoxy resin is used as the binder, the set incision can be absorbed by the binder component. This is probably due to the abnormal load. On the other hand, although the resinoid grindstone according to the present invention of Examples 1 and 2 has a lower porosity than the grindstone of Comparative Example 1, no abnormal increase in grinding resistance was observed. This result is considered to be due to the fact that the set incision was absorbed by the binder component because a flexible epoxy resin was used as the binder.
2-2. Workpiece removal amount Table 3 shows the results of the workpiece removal amount.

Since the conditions of the grinding test are intended for finishing, the amount of work material removal was generally small compared to the normal case. Excluding Comparative Example 1 in which the grinding test was stopped, when the grindstone of Example 1 was used, the amount of work material removed was larger than that of Example 2. This result is considered to be due to the fact that the quantitative ratio between the flexible epoxy resin used as the binder and the aromatic glycidyl ether type epoxy resin matched the grinding conditions. Therefore, in the present invention, a grindstone suitable for the grinding conditions can be provided by appropriately changing the quantitative ratio of the flexible epoxy resin and the aromatic glycidyl ether type epoxy resin.
2-3. Finished surface roughness Table 4 shows the results of the finished surface roughness of the work material.

  Generally, in the relationship between the grain size of the abrasive grains and the finished surface roughness, the finished surface roughness is usually rougher as the average grain size of the abrasive grains is larger. However, looking at the results in Table 4, in the grindstones of Examples 1 and 2 in which # 220 abrasive grains having a large average particle diameter were used, Comparative Example 1 in which # 1000 abrasive grains having a small average particle diameter were used. Compared with the whetstone of this invention, it was ground especially to the setting incision of 300 micrometers, and almost the same finishing surface roughness was obtained.

  Conventionally, in order to prevent chipping and microcracks, it is common to use abrasive grains having a small average particle diameter. If # 1000 abrasive grains are used, the influence of chipping is considered to be minimized. According to the results of the grinding test, Examples 1 and 2 in which # 220 abrasive grains having a large average grain size were used and Comparative Example 1 in which # 1000 abrasive grains having a small grain size were used were used. Therefore, the resinoid abrasive grains according to the present invention are considered to have achieved good surface roughness by preventing chipping and microcracks by using a flexible epoxy resin as a binder. It is done.

  The resinoid grindstone according to the present invention can be used for cylindrical grinding, surface grinding and internal grinding for the purpose of rough grinding and finish polishing, and can also be applied to final finishing such as honing. As the work material, it can be applied to ferrous materials and non-ferrous materials, especially grinding and polishing of hard and brittle materials such as carbide, silicon, alumina, carbide, nitride, sapphire, quartz, various glass and other ceramic materials. In particular, it is preferably used for finish polishing of the edge of a TFT liquid crystal glass material. In addition, the resinoid grindstone according to the present invention can also be suitably used for deburring of press punched metal parts, polishing of thin plate-like workpieces with unevenness, and control grindstones for centerless grinding.

FIG. 1 is a conceptual diagram showing a method for measuring the rebound resilience of a grindstone. FIG. 2 is a conceptual diagram showing a method for measuring a 25% compression hardness value of a grindstone.

Explanation of symbols

1 Load measurement Pressurizing head 2 Grinding wheel for test 3 Lower base 4 Pressing direction (vertical direction from top to bottom)
5 Steel balls

Claims (8)

  A resinoid grindstone in which abrasive grains are fixed with an epoxy resin, wherein the epoxy resin is a flexible epoxy resin.   The resinoid grindstone according to claim 1, wherein the flexible epoxy resin is a dimer acid-modified epoxy resin.   The resinoid grindstone according to claim 1 or 2, wherein the epoxy resin contains an aromatic glycidyl ether type epoxy resin up to 40% by weight based on the total weight of the epoxy resin.   The resinoid grindstone according to claim 3, wherein the aromatic glycidyl ether type epoxy resin is a bisphenol A type epoxy resin or a bisphenol F type epoxy resin.   The said resinoid grindstone is made into a multi-pore by using a powder or liquid foaming agent, an inorganic or organic pore-forming agent, or surfactant, The any one of Claims 1-4 characterized by the above-mentioned. The resinoid grinding wheel according to 1.   The resinoid grindstone according to any one of claims 1 to 5, wherein the resinoid grindstone has a rubber hardness of 50 to 90 as measured by a rubber hardness A scale.   The resinoid grindstone according to any one of claims 1 to 6, wherein a 25% compression hardness (JIS K6767) of the resinoid grindstone is 1.0 to 35.0 MPa. The resinoid grindstone according to any one of claims 1 to 7, wherein a rebound elastic modulus of the resinoid grindstone is 5 to 20%.

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