JPS6317594B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a rubber elastic grindstone using composite abrasive grains and a method for manufacturing the same, and particularly to providing a grindstone that has good conformability and excellent uniform polishing when processing curved surfaces having complex shapes with severe irregularities. Various known flexible and elastic grindstones have been developed as conventional elastic grindstones, and although their structures and materials are manufactured in a variety of ways, the term "elastic grindstone" generally refers to rubber-elastic or elastic grindstones such as plastic foam. It is often thought that conventional elastic whetstones have the same elasticity as these, but the elastic whetstones used as rotary abrasive tools have an elasticity that is far from what is commonly thought of. Therefore, there was an urgent need to develop an elastic grindstone suitable for machining curved surfaces with highly uneven and complex shapes. Therefore, an elastic material such as a flexible sponge rubber with desired pores has a completely suitable structure for curved surface machining and is suitable for the purpose of following the conformability, but it cannot withstand the conditions of practical use as a rotary grindstone. The most important problem is that it has not been possible to find a good bond between the abrasive grains and the porous rubber material. Therefore, the inventor of the present invention conducted basic experiments regarding this important issue and found the following conclusion. That is, in the method of bonding abrasive grains and porous rubber, first, in order to bond a chemically non-polar rubber with a polar abrasive, both the polar and non-polar parts must be bonded. It is necessary to use a substance that has the following characteristics, and the substance must have an excellent adhesive effect.However, if such a substance impairs rubber elasticity or inhibits foaming, the purpose cannot be achieved. I can't. It has been difficult to find a desired organic binder to firmly bind such contradictory polar substances because the particles of the abrasive grains are too large. Next, in order to physically join, an appropriate number of abrasive grains are aggregated into a lump using a ceramic sintering agent to form granules of an appropriate size with pores. In addition to the rubber dough,
The porous rubber obtained through the pressurization and vulcanization process with the addition of a foaming agent enters the pores of the composite abrasive grains, and the terpene-modified phenol resin with good compatibility is added to the 100% rubber. It has been found that by adding 5 to 20% of the abrasive grains, the adhesion is improved by improving the "wetting" between the abrasive grains and the rubber material, and the bond is slightly stronger due to the crosslinking of the rubber material or the bonding with the rubber material by the methylol group. Ta. As a result, we succeeded in developing a rubber elastic grindstone using composite abrasive grains that is completely different from conventional elastic grindstones and can withstand practical use conditions.The gist of this invention is as follows. . That is, the first aspect of the present invention is that the main body of the grinding wheel is made of a rubber-elastic compound using composite abrasive grains, which is made by integrally bonding inorganic composite abrasive grains having pores on the outer surface to a rubber-elastic compound having a spongy pore structure. The second type is a grindstone, in which a suitable amount of rubber is mixed with a vulcanizing agent, a vulcanization accelerator, a softening agent, an inorganic filler, a terpene-modified phenolic resin, a blowing agent, etc., and there are pores on the outer surface. The dough mixed with an appropriate amount of inorganic composite abrasive grains is vulcanized and foam-molded, or after vulcanization and foaming, the grinding wheel itself is formed into a spongy pore structure. This is a method for manufacturing rubber elastic grindstones using composite abrasive grains. Note that the inorganic composite abrasive grains in the present invention are obtained by adding and firing an appropriate amount of an inorganic binder and a pore-forming agent that forms pores to an appropriate number of abrasive grains, and
This term refers to the binder that has a large number of pores on its outer surface, etc., and is in the form of granules (agglomerates) of a suitable particle size. Furthermore, the inorganic binder here is: If an organic binder is used for composite abrasive grains, the organic chemicals (hardening agent, accelerator) will inhibit the foaming of the whetstone body, preventing it from becoming spongy, and the cost of manufacturing the composite abrasive grains in granular form will increase. This is because the amount increases. In each of the above-mentioned aspects of the present invention, the abrasive grains are made of inorganic composite abrasive grains with pores, and the main body of the whetstone is made of a spongy continuous pore structure. This is because the effects can be expected. (1) Since inorganic composite abrasive grains with pores on the outer surface are used, the rubber elastic compound easily enters into the pores of the composite abrasive grains due to the intervention of terpene-modified phenolic resin when forming the abrasive stone, and the vulcanization process Together with this, the rubber elastic compound that has entered the composite abrasive grains becomes one with each other, and the bonding force between the abrasive grains and the rubber material is very strong, eliminating the risk of them coming off and scattering during use. (2) The main body of the whetstone has a spongy continuous pore structure, so it has excellent cushioning properties.
The conformability to curved surfaces is ideal. In addition, since it has excellent rebound resilience, even if the abrasive material is rough, it is possible to obtain a soft, uniform polished surface and a good finished surface even if the abrasive material is rough. (3) Since it is porous due to its continuous pore structure, it has excellent heat dissipation effects and does not cause polishing burns or clogging. (4) Due to the cushioning effect unique to the porous material, there is little vibration or resistance during use, allowing workers to perform comfortable polishing work without feeling fatigued, and also preventing injury if they come into contact with the grindstone during use. There is no such danger. In order to clarify the above-mentioned gist of the present invention and to specifically explain the structure and effects of the present invention, an example of a rubber elastic grindstone using composite abrasive grains according to the present invention will be described in detail as follows. That's right. It goes without saying that the present invention is not limited to the following examples. In other words, the applicant first developed the patent application in 1973.
69665 (Japanese Patent Publication No. 56-52714), by adding an appropriate amount of an inorganic binder and an appropriate amount of a pore-forming agent that forms pores by firing,
The granules are made into granules of an appropriate particle size, which are fired, and the inorganic composite abrasive grains having a large number of pores on the outer surface of the binder and the rubber elastic compound are mixed in the following compounding ratio (all weight ratios). The mixture was mixed and kneaded well.

【table】

[Table] Crush the kneaded dough as described above into suitable sizes, or cut sheets of suitable thickness into grindstone-sized pieces, place them in a mold, and perform primary processing at a temperature of 139°C. After vulcanization, this is transferred to a secondary mold and subjected to secondary vulcanization at a temperature of 160℃, which increases the foaming ratio.
This is a rubber elastic grindstone that uses flat composite abrasive grains that have 2.4 times better cushioning properties. The rubber elastic grindstone using the composite abrasive grains produced as described above has many of the excellent effects described above, and is practical as a rotary abrasive tool. When used for this purpose, it exhibited remarkable effects that could not have been predicted previously. Therefore, an example of this effect is as follows. Ceramics such as bowls and plates have an unglazed base part to prevent fusion during the firing process, and conventionally, the base part is post-processed (polished) by hand. Pressure welding of thin ceramics using conventional grindstones with poor elasticity poses a danger to the human body due to damage to the ceramics, and the grinding process is also insufficient because it does not conform to curved surfaces. This is a process that workers avoid because it generates a lot of abrasive dust. When the rubber elastic grindstone using the composite abrasive grains of the above example was compared with the elastic grindstone conventionally used in the conventional manual polishing method, excellent effects as shown in the table below were confirmed.

【table】

[Table] In addition, we have improved the work environment using conventional elastic grindstones and automated ceramic polishing, which is a process that suffers from high costs.
Many attempts have been made in the past, but as is clear from the table above, various drawbacks and the development of an appropriate grinding wheel that can be automated have delayed the realization of an automatic polishing machine. The development of the rubber elastic grindstone according to the present invention, which has a foaming ratio of 2.4 times, has made automatic grinding possible, and the productivity has been reduced to 350 pieces/grinding compared to conventional manual grinding.
Processing production has significantly improved to 700 to 800 pieces per hour, and the polished surface has achieved excellent results that are incomparable to previous models. In addition, by changing the foaming ratio, the conformability and abrasiveness also change, and in addition to the above-mentioned ceramic polishing, the former can realistically express the three-dimensional effect of the wood grain without causing burns, for example, in embossing the wood grain or cutting stainless steel plates. The latter showed a good cutting effect, with no burr-like cutting debris and sharp cutting ability. In addition, in this invention, the respective components of the inorganic composite abrasive grains and rubber elastic compound, as well as the molding and vulcanization method of the grinding wheel, etc., may be appropriately selected within the scope of achieving the above-mentioned objectives and the above-mentioned effects of this invention. Needless to say, it is fine to have such regulations. As will become clear from the above description, according to the present invention, the drawbacks of conventional elastic grinding wheels can be very easily and effectively improved, and the particle size and granule size of the abrasive grains can be adjusted to suit processing purposes. It must be said that the practical benefits brought about by this invention are great because it can be used in a very wide range by selecting an appropriate expansion ratio.

Claims (1)

[Scope of Claims] 1. Composite abrasive grains characterized in that the main body of the whetstone is formed by integrally bonding inorganic composite abrasive grains having pores on the outer surface to a rubber elastic compound having a sponge-like pore structure. Rubber elastic grindstone used. 2 Add a vulcanizing agent, a vulcanization accelerator, a softening agent to an appropriate amount of rubber,
An inorganic filler, a terpene-modified phenolic resin, a foaming agent, etc. are added thereto, and an appropriate amount of inorganic composite abrasive grains having pores on the outer surface are added thereto, and the mixed dough is vulcanized and foam-molded, or vulcanized. A method for producing a rubber elastic grindstone using composite abrasive grains, which comprises foaming the whetstone with sulfur, and then molding the main body of the whetstone, thereby making the main body of the whetstone have a spongy pore structure.