JPH0680954A - Abrasive material - Google Patents

Abstract

PURPOSE:To obtain an abrasive material which is excellent in abrasive action and gives the surface of an abraded article a good roughness by grinding sprues, runners, defective moldings, etc., produced in molding a thermosetting resin molding material. CONSTITUTION:When a high hardness is required, an abrasive material pref. contains a phenol resin or a melamine resin as the resin component and glass or silica as the filler; when flexibility is required, an epoxy resin, a polyester resin, or a polyurethane resin as the resin component and a woodflour or pulp as the filler. The material usually has a particle size of 100-1,200mum and is suitable for deburring an electronic part, a molded plastic or a metal part, etc. An example of the material is obtd. by grinding sprues, runners, etc., produced in molding a phenol resin molding material contg. 50wt.% woodflour and has a particle size of 200-400mum. a true specific gravity of 1. 4, and a hardness of 110.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an abrasive suitable for deburring molded articles such as electronic parts, metal products, and plastic products.

[0002]

2. Description of the Related Art Conventionally, alumina has been used as such an abrasive.
Hard materials such as silicon carbide and glass, and soft materials such as nylon, polycarbonate and walnut shell powder have been used.
These abrasives are selected and used according to the purpose and application, but with hard materials, it is easy to scratch the mating material,
In the case of a soft material, the polishing force may be insufficient, and an intermediate hardness is required, and several types of such abrasives have been introduced, but there are problems in strength, durability and the like.

[0003]

The present inventors have made various studies on abrasives from such a viewpoint, and have completed abrasives having appropriate hardness and durability.

[0004]

The present invention relates to an abrasive having a predetermined particle size by crushing a cured product such as a sprue, a runner and a defective molded product generated during molding of a thermosetting resin molding material. , Such abrasive has hardness, durability,
Satisfying the cost, etc., it is possible to recycle and recycle what was used as a waste in the past. In the present invention, the thermosetting resin molding material contains a phenol resin, an epoxy resin, a melamine resin, a urea resin, a polyester resin, a polyurethane resin or the like as a resin component, in addition to the resin component, wood powder, organic matter such as pulp, or the like. It contains 30 to 70% of an inorganic substance such as calcium carbonate, talc, silica stone, or glass as a filler, and is used for producing molded articles such as electric parts and machine parts. Sprues, runners, or occasional defective moldings produced in the mold during the heat molding of such molding materials have been conventionally discarded. In recent years, the amount of waste has continued to increase, which leads to deterioration of living environment and waste of limited resources. Conversion to structure is important.

Under such circumstances, there has been a demand for recycling of renewable resources, and the present invention is also applicable to the purport thereof. Although the present invention serves the purpose of resource saving, it goes without saying that it is very useful in terms of quality as well as that. The cured product of the thermosetting resin molding material used in the present invention has many kinds of resins and fillers, and a wide selection can be made to meet fine requirements such as hardness and polishing performance depending on the purpose. Conventionally, one of the reasons why a cured product of a thermosetting resin is not used for such an application is considered to be poor pulverizability of the cured product. In particular, those containing inorganic fillers were difficult to commercialize because the abrasion of the crusher was remarkable, but the research of crushers has progressed rapidly in response to the demands of the times, and a crusher with good performance is being developed. As a result, a pulverized product of such a cured product can be easily obtained.

The cured product of the thermosetting resin molding material used for the abrasive of the present invention is, as described above, the type of the resin,
There are various kinds of fillers with different types and blending amounts,
When high hardness is required, phenol resin as resin component, melamine resin, glass as filler component, those containing silica are suitable, and when soft hardness is required, epoxy resin, polyester resin as resin component, Those containing a polyurethane resin and wood powder or pulp as a filler component are preferable. The particle size is also an important property as an abrasive, and currently, particles having a particle size of about 100 to 1200 μm are widely used. However, the abrasive of the present invention can be used for all particle sizes by appropriately selecting the grinding conditions. You can

[0007]

[Examples] Abrasives were prepared by crushing sprues and runners generated during molding of a phenol resin molding material containing 50% by weight of wood powder. Its characteristics are particle size 200-400μ
m, true specific gravity 1.4, hardness (Rockwell M scale) 1
It was 10. The abrasive material was used to deburr a phenolic resin molded product for electric parts (glass fiber filler). For comparison, deburring was performed using alumina and nylon as abrasives, respectively. The results are shown in Table 1.
It was the street.

[0008]

[Table 1]

[0009]

As is clear from the examples, the abrasive of the present invention has excellent polishing power and the surface roughness of the polished molded product is good. Further, various types of cured molding material can be selected depending on the hardness of the molded product to be polished. Furthermore, sprues, runners, etc., which have been conventionally discarded, can be recycled.

Claims (1)

[Claims] 1. An abrasive comprising a cured product such as a sprue, a runner, or a defective molding product generated during molding of a thermosetting resin molding material.