JPS601146B2 - Composition with improved grindability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition with improved grindability and greater grinding power.

More specifically, the present invention relates to a composition that improves and improves grinding force by increasing the adhesion between grinding abrasive grains and a thermoplastic polymer.

Conventionally, whetstones, abrasive paper, wire brushes, etc. have been used for polishing or grinding.

However, nuclear polishing and abrasive materials have poor compatibility with the object to be ground, making them unsuitable for objects to be ground with many curved surfaces.

Recently, abrasives with improved compatibility have been developed, such as those in which abrasive grains are fixed to synthetic polymer threads with adhesive, or those in which abrasive grains are incorporated into synthetic polymer threads. is being developed. It is true that this abrasive thread body has improved conformability, but due to insufficient adhesion between the abrasive grains and the thermoplastic polymer, voids are created between the two, and during the grinding process, the abrasive grains is peeled off or fallen off from the synthetic polymer, resulting in a decrease in the grinding force and premature wear of the grinding thread, so that it is only used for cleaning or, at most, for polishing.

On the other hand, the coating on steel materials etc. that has a strong oxide coating on the anchor
Currently, waste acid is generally removed using hydrochloric acid, but the treatment of waste acid is becoming a problem in terms of pollution.

The best way to eliminate such pollution is to mechanically remove it by grinding, but the conventional mechanical grinding methods each have their own shortcomings.

For example, there is a method of removing the coating on steel materials by spraying steel balls or abrasive grains under high pressure, but the equipment is expensive, the spraying pressure may damage the steel material, and the particle size of the steel balls or abrasive grains There are many problems in actual use, such as difficulty in selecting a suitable one, high noise and pollution. This invention was developed as a result of intensive research to solve these problems.
The present invention was achieved by discovering a thermoplastic composition for grinding that meets these requirements.

This invention consists of: (1) Thermoplastic polymer (2) Discussion: 0.0% ethylene-pinyl acetate copolymer containing 5 to 40% of bier acetate per 100 parts by weight of the thermoplastic polymer.
This is a composition with improved grinding properties consisting of grinding abrasive grains (parts by weight of 01 to 2).

Examples of thermoplastic synthetic polymers in this invention include nylon 6, nylon 6-6, nylon 6-JI0, nylon 6-12, nylon 11, nylon 12, polyamides such as copolymerized nylon containing these, and polyethylene terephthalate. , polybutylene terephthalate, polyesters containing copolymers thereof, polypropylene, polyvinyl alcohol, etc., and the effect is particularly remarkable when polyamides and polyesters are used.

In the ethylene-vinyl acetate copolymer, it is desirable that vinyl acetate be contained in an amount of 5 to 4% by weight.

When the vinyl acetate content is outside this range, the grinding ability decreases. The amount of the ethylene-vinyl acetate copolymer is preferably 0.01 to 20 parts by weight, most preferably 0.1 to 17 parts by weight, based on 100 parts by weight of the thermoplastic synthetic polymer. If it is less than 0.01 part by weight, the grinding force decreases, and if it exceeds the cloud amount part 2, the grinding molded object becomes soft and the grinding force decreases. The grinding abrasive material may be any commonly used material, including fused alumina, siliceous carbide zirconia, carbide, nitride, boride, artificial abrasive materials such as artificial diamond, diamond, corundum, etc.
Examples include emery, gokuru stone, poppy stone, natural abrasive material, and glass.

These may be used alone or in combination. The particle size of the grinding abrasive grains is preferably #40 to #1000.

4 The proportion of abrasive grains in the composition is preferably 10 to 7% by weight.
If L is less than 70%, no grinding force can be expected, and if L is more than 70%, molding becomes extremely difficult. The grinding composition of this invention can be obtained in various ways. For example, a method of melting a thermoplastic synthetic polymer and adding grinding abrasive grains and ethylene-pinyl acetate copolymer to it, or melting a thermoplastic synthetic polymer granule or powder as homogeneously as possible,
There is a method in which particles or powder of ethylene-vinyl acetate copolymer are mixed with grinding abrasive grains and molded while melting in an extruder. The composition of this invention is used for grinding and polishing in the form of yarn, film or other suitable form.

In addition, when melt-extruding this thermoplastic molding mixture, it is preferable to maintain the temperature at or above the softening point of the thermoplastic synthetic polymer used.

When the composition of the present invention is used for grinding and polishing, it exhibits remarkable grinding ability compared to when conventional grinding materials are used.

Next, examples of this invention will be shown.

Example 1 An ethylene-vinyl acetate copolymer containing 4% by weight of vinyl acetate (molecular weight 1
0000) 2 parts by weight and silicon carbide abrasive grains #100 (
Add 4 parts by weight of T13 standard) and mix.

This mixture was melted at 26,000 yen using a melt extruder, passed through a spinneret into water at 2 room temperature, and after being drawn three times, a monofilament with a diameter of 1.0 mm was produced.

On the other hand, as a comparative example, a monofilament was manufactured under exactly the same conditions except that no ethylene-vinyl acetate copolymer was added.
Threads made of both compositions were cut into 10 fibers with a diameter of 30 cm (
Trim) 5-arc roll brush. 2000'mi
At a peripheral speed of n, the length of the middle school student is 35 meters, and the speed is 30 m/mjn.
Table 1 shows the grinding ability of the stainless steel plate.

As shown in the results in Table 1, it can be seen that the brush made of the abrasive thread produced using the composition of the present invention has significantly improved grinding power compared to the comparative example.

Example 2 100 parts by weight of nylon 6 chips with a relative viscosity of 3.2,
0.01 part by weight of an ethylene-vinyl acetate copolymer (molecular weight 30,000) containing 8% by weight of vinyl acetate and 25 parts by weight of fused alumina abrasive grains #240 are thoroughly mixed.

This mixture was melted at 260 q○ using a melt extruder and extruded through a paper thread nozzle into water at room temperature to produce a monofilament with a diameter of 1.0 mm after being stretched three times.
On the other hand, as a comparative example, a Mo-Z nofilament was produced under exactly the same conditions except that the ethylene-vinyl acetate copolymer was not added. These threads were made into a brush in the same manner as in Example 1.

Table 2 shows the grinding ability for stainless steel plates. Table 2 J As shown by the results in Table 2, it can be seen that the brush made of the abrasive thread produced using the composition of the present invention has significantly improved grinding power compared to the comparative example.

Example 3 Ethylene-vinyl acetate copolymer (molecular weight 50,000) containing 25% by weight of pinyl acetate in 100 parts by weight of polyethylene terephthalate of $p/c (19 polymers/100 units of chlorophenol liquid) 0.6 and 19 parts by weight of silicon carbide low particles #180 were added and mixed well.

This mixture was melted at 300 qo using a melt extruder, extruded into water through a paper thread nozzle, and stretched 5 times to a diameter of 1.0 qo.
A skin-like monofilament was produced.

On the other hand, as a comparative example, a monofilament was produced under exactly the same conditions except that the ethylene-vinyl acetate copolymer was not added. These threads were made into a brush in the same manner as in Example 1.

Table 3 shows the grinding ability for stainless steel plates. As shown in the results in Table 3, it can be seen that the brush made of the abrasive thread produced using the composition of the present invention has significantly improved grinding power compared to the comparative example.

Claims (1)

[Claims] 1 (1) Thermoplastic polymer (2) 0.01 to 20 ethylene-vinyl acetate copolymer containing 5 to 40% by weight of vinyl acetate based on 100 parts by weight of the thermoplastic polymer Parts by weight (3) A composition with improved grindability consisting of grinding abrasive grains. 2. In claim 1, the thermoplastic polymer is nylon 6, nylon 6-6, nylon 6-10, nylon 6-12, nylon 11, nylon 12, copolymerized nylon containing these, polyethylene terephthalate. A composition with improved grindability, which is a thermoplastic polymer selected from polybutylene terephthalate, polybutylene terephthalate, and copolyester containing these. 3. In claim 1, the composition has improved grindability, wherein the grinding abrasive grains are an artificial grinding material selected from fused alumina, silicon carbide, zirconia carbide, nitride, boride, and glass artificial diamond. thing. 4. A composition with improved grindability as set forth in claim 1, wherein the abrasive grains are a natural abrasive selected from diamond, corundum, emery, and garnet pumice.