JPH083542A - Abrasive material - Google Patents

Abstract

PURPOSE:To obtain an abrasive material high in abrasive power, high in the roughness of a molded product surface abraded, thus suitable for removing burrs developed during the molding process for electronic parts or plastic molded products (esp., resin-sealed ICs or LSIs). CONSTITUTION:This abrasive material is obtained by grinding a cured product obtained by hot-pressing a thermosetting resin composition, a homogeneous blend comprising 10-35wt.% of an epoxy resin, 5-20wt.% of a novolak-type phenolic resin, and 45-85wt.% of silica powder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abrasive suitable for removing burrs generated during molding of electronic parts, plastic products and the like.

[0002]

2. Description of the Related Art Conventionally, hard materials such as alumina, silicon carbide, and glass, and soft materials such as nylon, polycarbonate, and walnut shell powder have been mainly used as abrasives for post-treatment such as deburring of molded products. Has been done. In addition to these, recently, an abrasive of a thermosetting resin cured product having intermediate characteristics between the hard material and the soft material has been developed. This thermosetting resin cured material has a hardness that conventional materials do not have, and has come to be used considerably. However, the applications of molded products have been diversified year by year, and the characteristics required for abrasives have become strict and diversified. Especially for molded products related to electric parts, required characteristics such as dimensional accuracy are strict, and various measures are being taken to meet them.

[0003]

The present inventor examined various abrasives for post-treating a molded product from such a viewpoint, and completed an abrasive having appropriate hardness, abrasivity and durability. It is a thing.

[0004]

DISCLOSURE OF THE INVENTION The present invention comprises 10 to 35% by weight of an epoxy resin and 5 to 2 novolac type phenolic resins.
The present invention relates to an abrasive obtained by heating and pressurizing a thermosetting resin composition obtained by uniformly mixing 0% by weight and 45 to 85% by weight of silica powder, and pulverizing the cured product. It has abrasiveness and durability.

Abrasives have hitherto been used for removing burrs from metal products, plastic products, etc., removing deposits, surface treatments, etc.
An inorganic abrasive, depending on the quality of the object to be polished and the purpose of polishing,
Organic abrasives, metal abrasives, etc. have been used. Recently, the materials to be polished are diversified and the shapes are complicated,
Some have not been compatible with existing abrasives. The abrasive of the present invention has good polishing power and further has appropriate flexibility as compared with inorganic abrasives such as alumina, so that it does not damage the object to be polished and has good durability characteristics. is there.

The epoxy resin, which is the organic binder component of the abrasive of the present invention, has appropriate elasticity and high toughness,
The binding force with the filler is also very good. The silica powder itself may be used as an abrasive, but its polishing power is too strong and there is a great risk of damaging the object to be polished. The abrasive of the present invention has the feature that it does not damage the object to be polished by utilizing the polishing power of silica and binding it with an epoxy resin.

As described above, since the abrasive material of the present invention contains 45 to 85% by weight of silica powder in the epoxy resin composition as a raw material, it has excellent abrasiveness and does not damage the object to be abraded. Good durability. That is, by using the above-mentioned composite composition as the abrasive composition, it has both the polishing power of the inorganic abrasive and the flexibility of the organic abrasive.

The resin component consists of an epoxy resin and a novolac type phenol resin, and is 15 to 55% by weight in the composition.
Is. If it is less than 15% by weight, the silica content is large and the polishing force becomes too strong, and the bonding force becomes insufficient, resulting in poor durability. If it exceeds 55% by weight, the polishing power will decrease. The epoxy resin is preferably a novolac type or biphenol type epoxy resin from the viewpoint of toughness and bonding strength, and particularly preferably a cresol novolac type epoxy resin. On the other hand, the novolac type phenolic resin is preferably an alkylphenol, alkylbenzene or dicyclopentadiene modified novolac type phenolic resin having excellent flexibility.

The grain size of the abrasive of the present invention is usually 60 to 10.
It is in the range of 00 μm, but preferably 100 to 800 μm. If the particle size is smaller than this, the polishing power is small, and if the particle size is too large, the object to be polished may be damaged.

[0010]

EXAMPLE A composition having the following composition was molded by a transfer molding machine at 175 ° C. for 3 minutes to obtain a hardened material, which was crushed to remove fine powder to produce an abrasive having a particle size of 200 to 400 μm. Cresol novolac type epoxy resin 20 parts by weight Novolac type phenolic resin 10 Silica powder (average particle size 15 μm) 70 Wax 0.3 Carbon black 0.2 The obtained abrasive has a true specific gravity of 1.9 and hardness (Rockwell
M scale) 110.

Using this abrasive, burrs were removed from the epoxy resin molded product for electric parts. For comparison, deburring was performed using a cured melamine resin and glass beads as an abrasive. Table 1 shows the measurement results of the polishing characteristics (polishing power, surface roughness of the molded product).

[0012]

[0013]

As is clear from the above examples, the abrasive of the present invention has a good polishing power and a good surface roughness of the abraded molded product, which occurs during the molding of electronic parts and plastic molded products. Suitable for removing burrs, especially IC and L sealed with resin
It is suitable for removing burrs such as SI.

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Claims (4)

[Claims] 1. Epoxy resin 10 to 35% by weight, novolac type phenol resin 5 to 20% by weight, and silica powder 4
An abrasive comprising a thermosetting resin composition in which 5 to 85% by weight is uniformly mixed, and a cured product obtained by heating and pressurizing the pulverized product. 2. The abrasive according to claim 1, wherein the epoxy resin is a novolac type or biphenol type epoxy resin. 3. The abrasive according to claim 1, wherein the epoxy resin is a cresol novolac type epoxy resin. 4. The abrasive according to claim 1, wherein the novolac type phenol resin is an alkylphenol, alkylbenzene or dicyclopentadiene modified novolac type phenol resin.