KR950005073B1 - Diamond-resin wheel manufacturing method for grinding - Google Patents

Abstract

The method is for mass-producing the diamond resin wheel, specially used for high-precision grinding of crystal oscillators, Brown tubes and others. The diamond resin wheel production method comprises the steps of: heating the mixture of heat-hardening resin and synthetic diamond powder; crushing the hardened mixture; molding the crushed particles of the hardened mixture and an elastic resin.

Description

Manufacturing method of abrasive elastic diamond-resin wheel

The present invention relates to an abrasive diamond elastic wheel and a method for manufacturing the same, more specifically, an elastic diamond-resin used for polishing quartz crystal oscillator, crystal, CRT, special glass, ordinary glass, cemented carbide, heat-treated metal, ceramics, etc. It relates to a manufacturing method of a wheel.

Conventionally, the diamond wheel, which has been used for polishing quartz crystal, crystal, CRT, special glass, general glass, cemented carbide, heat treated metal, ceramic, etc., has excellent grinding power due to the characteristics of synthetic diamond, but has a high scratching effect due to its sharp cross section. It has also been pointed out as a problem that is inadequate for polishing irregular planes or curved surfaces.

In order to prevent such a scratch phenomenon, the development of polycrystalline diamond has been promoted and has been put into practical use. However, these diamonds have solved the scratch prevention, but the grinding power is superior to general synthetic diamonds, and the life is only 1/3, the price is 7 to 10 times higher, and the irregular flat or It is pointed out as a problem that it is inadequate for polishing a curved surface.

In addition, a problem of the prior art is that polishing must be performed in multiple stages. That is, in the case of the conventional metal wheel or resin wheel, it is possible to grind stepwise from 60 mesh to 100 mesh, 140 mesh, 500 mesh, and more than 500 mesh is impossible in the automatic line, for example, super precision such as polishing of semiconductor crystal oscillator In the case of polishing, the polishing should be carried out step by step by changing the abrasive to 1000, 1500, 2000, 4000 mesh by manual polishing method, which requires a lot of labor and time, and also poor polishing quality.

As a solution to this, attempts have been made to achieve polishing of a wide mesh range without scratching with an elastic resin wheel molded with industrial synthetic diamond particles and elastic rubber. There was a problem such as easy separation from the rubber was not possible for performance.

Accordingly, the present inventors have continually researched to solve the above problems of the prior art and to provide a method of manufacturing an elastic polishing wheel with improved performance. Thus, diamond particles and thermosetting resins are mixed and heat-cured to be pulverized. When molding a particulate diamond-thermosetting resin binder and an elastic resin together, the particulate diamond-thermosetting resin binder in which the diamond is firmly bonded by the thermosetting resin has a larger bonding surface than the diamond particles and the elastic resin of the thermosetting resin Excellent adhesion to the diamond prevents diamond particles from desorption from the wheel, and by polishing, the new diamond surface is sequentially exposed to the surface of the particulate diamond-thermosetting resin assembly, thereby revealing a new face as if the polycrystalline diamond were polished. It does not cause scratches because of the elasticity of the wheel and the elasticity of the wheel. Also, the wheel's elasticity can be used for grinding on the irregular flat or curved surface and directly in the range of 15,000 mesh from 500 mesh. In addition, it has been found that not only enables ultra-precision polishing, but also provides a highly reliable elastic diamond-resin wheel capable of mass production at a low price with little defects.

Therefore, the method for producing the abrasive elastic diamond-resin wheel of the present invention is a 20-160 mesh particulate diamond-thermosetting resin obtained by pulverizing a mixture of 100 parts by weight of the thermosetting resin and 20 to 70 parts by weight of the synthetic diamond powder together. It is characterized in that the molded body and the molding together with the binder resin.

In the present invention, other additives may be incorporated into the particulate diamond-thermosetting resin assembly according to the use of the elastic wheel. Examples of such optional additives include abrasives other than diamond powder, fillers, curing accelerators, and pore-forming agents. The other abrasives are selected from the group consisting of particulate iron oxide, chromium oxide, cerium oxide, silicon carbide, alumina, silica, garnet, or mixtures of two or more thereof, and are particles thereof. The filler is selected from the group consisting of SiO ₂ , limestone, bentorite, wood flour or mixtures of two or more thereof, the permissible amount being up to two times the thermosetting resin content. The pore-forming agent is dissolved after the formation of the particulate diamond-thermosetting resin binder to form a plurality of pores in the particulate diamond-thermosetting resin binder to further improve the competencies between the particulate diamond-thermosetting resin binder and the elastic resin and improve the grinding force of the abrasive wheel. Functioning is crystalline sodium sulfate or anhydrous sodium chloride, the allowable amount of which is up to 1.5 times the thermosetting resin content. A hardening accelerator is for promoting hardening of a thermosetting resin, for example, magnesium oxide.

In the present invention, preferred examples of the thermosetting resin constituting the particulate diamond-thermosetting resin binder together with the diamond powder or other optional additives include phenol resins, phenol modified resins, epoxy resins, epoxy modified resins, and the like.

Elastomeric resins that are molded and molded with the particulate diamond-thermosetting resin binder include natural or synthetic rubbers, elastomers, and the like, and preferred examples thereof include polyurethane, polyurethane elastomer, polyurethane foam, and acrylonitrile. Butadiene rubber (NBR) and neoprene rubber.

In the present invention, the granular diamond-thermosetting resin binder is formed into a thin thread, or formed into a hot die, for example, by continuously passing a mixture of a thermosetting resin and a synthetic diamond powder through a plurality of extruders whose nozzle diameter gradually decreases. It is preferable to obtain by forming into a thickness that is easy to pulverize, then curing and pulverizing. In particular, the extrusion method is more preferable because the shape of the extruder nozzle can be easily obtained by changing the shape of the extruder nozzle into, for example, a triangle, a square, a polygon, a circle, or the like, so as to easily obtain a granular diamond-thermosetting resin binder suitable for a specific wheel application. .

Hereinafter, the present invention will be described more clearly by illustrating non-limiting examples. In the embodiments to be described later, ratios and percentages, which are not otherwise defined, are based on weight.

Example 1

An elastic diamond-resin wheel was manufactured through the following process.

① Step 1: Add 80g of phenolic resin powder, 55g of synthetic diamond powder of 15,000 ~ 20,000 mesh, 15g of magnesium oxide, 300g of 1μ silicon carbide of particle size and 150g of anhydrous sodium sulfate in a ballistic ball mill and mix for 12-14 hours.

② Second step: 600g of the summed powder obtained in the first step and 100g of phenolic resin solution of 74% of solids content are mixed firstly in a blender, and then secondly mixed using a mixing three-stage roller, and then the temperature is 50 ° C and the nozzle diameter. After passing through a hydraulic extruder of 30 ~ 50mm extruded into a rod shape and cut to a certain length, it is extruded again in a hydraulic ultra-high pressure extruder having a temperature of 50 ~ 60 ℃, a nozzle diameter of 0.5mm.

③ The third step: wrap the filamentary extrudate obtained in the second step in the rectangular steel frame at 0.2 ~ 0.5mm interval, put it in the oven, heat it up to 50 ℃ instantaneously, and raise it to 160 ℃ by 10 ℃ every hour. After holding for 16 hours at 160 ° C., turn off the power, cool slowly in the oven, take out of the oven, and remove the hardened filament from the mold.

④ 4th step: Put the cured product obtained in the 3rd process into the grinder composed of two high carbon steel rollers with the irregularities of 0.3 ~ 0.5mm on the surface and grind it with 50 mesh at the rotation speed of 60 ~ 180rpm.

⑤ The fifth step: The particulate diamond-thermosetting resin conjugate obtained in the fourth step was added to a stirring tank containing 50-70 ° C. hot water, stirred for 10-30 minutes, and the anhydrous sodium sulfate introduced in the first step was eluted, and the slurry was The vacuum is filtered, dehydrated in a centrifuge and dried.

⑥ Step 6: Mix 110 g of the particulate diamond-thermosetting resin mixture obtained in Step 5 while maintaining a foamable monomer mixture composed of 45 g of polyol, 37 g of polyisocyanate, and a small amount of blowing agent at a temperature of 20 to 40 ° C. After filling the mold and held for 5 to 10 minutes, it was removed from the mold and maintained for 12 hours at a temperature of 35 to 40 ℃ in an oven to prepare an elastic diamond-resin wheel in which a particulate diamond-thermosetting resin mixture was incorporated into the urethane foam. do. The prepared resin wheel was found to have a sponge structure when observed under a microscope. In addition, as a result of using the prepared sponge-like elastic wheel for the polishing of irregular flat or curved plate glass, even if it was polished for a long time, the desquamation of the diamond node and the scratch on the surface of the plate glass did not occur. Irregular planes or curved surfaces were polished with high precision over a wide mesh range and no excessive heat of polishing occurred.

Example 2

A polishing wheel was manufactured in the same manner as in Example 1, except that 100 g of the diamond-thermosetting resin binder was used in phase 6 without using a blowing agent. As a result of using the prepared elastic wheel for the polishing of irregular flat or curved plate glass, the diamond particles and the scratching of the glass surface did not occur even after long term polishing. It was polished with high precision over the mesh range and no excessive heat of polishing was generated.

Example 3

60 g of phenolic resin powder, 20 g of synthetic diamond powder of 15,000-20,000 mesh, 6 g of magnesium oxide, and 100 g of alumina having a particle size of 1 μ were mixed in an elastic ball mill and mixed for 12 to 14 hours. After molding under pressure at a temperature of ˜175 ° C. for 10 to 20 minutes, the molded product was removed from the mold and subjected to post curing for 16 hours at a temperature of 160 ° C. in an oven. The obtained hardened | cured material is put into the grinding | pulverizer which consists of two high carbon steel rollers which formed the unevenness | corrugation of 0.3-0.5 mm on the surface, and grind | pulverizes to 50 meg at the rotation speed of 60-180 rpm. 110 g of the particulate diamond-thermosetting resin mixture obtained by grinding and 45 g of polyol isocyanate and 37 g of polyisocyanate and a trace amount of a foaming agent were mixed and filled into a mold kept at 45 ° C. for 5 to 10 minutes. After maintaining, the resultant was removed from the mold and maintained at an oven temperature of 35-40 ° C. for 12 hours to prepare an elastic diamond-resin wheel in which a particulate diamond-thermosetting resin mixture was mixed in a urethane foam.

As a result of using the produced elastic wheels for the polishing of irregular flat or curved plate glass, the diamond particles did not scratch or scratch on the glass surface even after prolonged polishing. Polished with high precision over a wide mesh range, no excessive heat of polishing was generated.

Claims (2)

In the manufacturing method of the abrasive elastic diamond-resin wheel, a 20-60 mesh particulate diamond-thermosetting resin mixture obtained by pulverizing a mixture of 100 parts by weight of the thermosetting resin and 20 to 70 parts by weight of the synthetic diamond powder and Manufacturing method characterized in that the molding with the elastic resin. The thermosetting resin according to claim 1, wherein the thermosetting resin is selected from the group consisting of phenol resins, phenol modified resins, epoxy resins, epoxy modified resins, and the elastic resins are polyurethanes, polyurethane elastomers, polyurethane foams, acrylonitrile- A manufacturing method selected from the group consisting of butadiene rubber and neoprene rubber.