JPH0236076A - Monofilament for polishing brush - Google Patents

Abstract

PURPOSE:To obtain a monofilament having the characteristic optimum for a polishing brush by using a polyetherketonepolymer excellent in heat resistance, chemical resistance, wear resistance, etc. CONSTITUTION:A monofilament for a polishing brush is formed by the monofilament which is virtually composed of an aromatic polyether-ketone and whose strength is >=3g/d, elongation 20-50% and initial Young's modulus 40-80g/d. The monofilament having the characteristic optimum for a polishing brush is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a monofilament for a polishing brush used for polishing metal surfaces and the like.

(Prior Art) For polishing metal surfaces, etc., a roll-type polishing Iff brush is used, which is made up of bristles made by cutting 9 synthetic resin monofilaments into appropriate lengths.

Since such polishing brushes come into contact with hot metal surfaces while rotating at high speed in the presence of alkaline or acidic water or oil emulsions, monofilaments for polishing brushes must have appropriate rigidity and wear resistance suitable for polishing. In addition to strength, heat resistance and chemical resistance are also required.

Traditionally, monofilament for polishing brushes.

Polyamides such as nylon 6 and nylon 66 and polyesters such as polyethylene terephthalate have been used, but it has been difficult to fully satisfy the above-mentioned required properties.

In other words, polyamide swells due to water absorption,
I'*J properties may deteriorate, and polyester has problems such as insufficient hydrolysis resistance and a tendency to reduce strength.

On the other hand, polyetherketone is known as a polymer with excellent heat resistance and chemical resistance (Japanese Patent Laid-Open No. 54-90296
issue).

Efforts have been made to take advantage of the characteristics of this polymer to produce fibers suitable for industrial material applications.

It is also considered to use the obtained fibers as heat-resistant and chemical-resistant brushes (for example, Japanese Patent Application Laid-Open No. 57-191
No. 322, No. 62-231016, etc.).

However, for polyetherketone monofilament which has properties particularly suitable for polishing brushes, Lr:'
! It has not been.

(Problems to be Solved by the Invention) The present invention aims to provide a monofilament made of polyetherketone polymer with excellent heat resistance, chemical resistance, abrasion resistance, etc., and having characteristics suitable for use in polishing brushes. It is something to do.

(Means for Solving the Problems) The present invention solves the above problems, and is a monofilament consisting essentially of aromatic polyetherketone, having a strength of 3 g/d or more and an elongation of The gist of the present invention is a monofilament j. for polishing brushes characterized by having an initial Young's modulus of 20 to 50% and 40 to 80 g/d.

What is aromatic polyetherketone as used in the present invention?

This is a polymer in which the repeating position m is represented by (+), (If) or (I■) below.

-0-◎-0-◎-c o -◎-(II)00-■-
〇-◎-co-@-(III) (1) is polyetherketone (PEIO, (n) is polyetheretherketone (PEEK), (I[[) is polyetherketoneketone (P E K K) This is a well-known polymer.

The monofilament of the present invention comprises such a polymer,
It is obtained by melt-spinning and stretching under appropriate conditions and, if necessary, heat-treating.

The first feature of the monofilament of the present invention is that it has a strength of 2 and 3.
If the zero strength, which is g/+1 or more, is less than 3 g/d, it is difficult to put it to practical use as a polishing brush.

Moreover, the second feature is that the elongation is 20 to 50%, preferably 30 to 40%. If the elongation is lower than this range, the rigidity will be poor and the brush will not return easily when being polished, which is undesirable. On the other hand, if the elongation is higher than this range, it will elongate due to the heat treatment under tension that is performed to correct curling curls, making handling a national problem.

Furthermore, the third feature is that the initial Young's modulus is 40 to 80 g.
/d. If the initial Young's modulus is lower than this range, the rigidity will be poor and the polishing efficiency will be poor. On the other hand, if the initial Young's modulus is higher than this range, the rigidity will be too high, the wear resistance will be poor, and the product will not be able to withstand long-term use.

The monofilament has a diameter of approximately 0.1 to 0.5 mm.

Next, two methods of manufacturing the monofilament of the present invention will be explained.

First, a polyetherketone polymer is melt-spun to obtain an undrawn monofilament. The polymer used for spinning has an intrinsic viscosity of 0.6 or more, preferably 0.7, as measured at 25°C using 96% sulfuric acid as a solvent. Those with higher viscosity are used. However, if a material with too high a viscosity is used, the spinning temperature must be set to a very high temperature, which may cause problems such as gelation of the polymer. It is appropriate to use

Further, it is preferable to blend about 5 to 30% by weight of abrasive fine powder into the polymer, since this can increase the polishing efficiency. Examples of such abrasives include alumina, emery, silicon carbide, silicon nitride, etc., and in consideration of spinning and drawing properties, fine powders of about 80 to 00 mesh are preferable. Furthermore, in addition to the abrasive, additives such as a matting agent 1 coloring agent may be added.

Polyetherketone polymers have high melting points.

And because of its high viscosity, it requires a higher temperature than the normal melt spinning method.

That is, it is discharged from a spinneret maintained at a temperature 20 to 80° C. higher than the melting point, and passed through a high-temperature atmosphere (heating hood) directly below the spinneret. The length of the heating hood is suitably 5 to 20 cm, preferably 5 to 15 am, from the spinneret surface, and the temperature is 200 to 400°C, preferably 250 to 350°C. If the length of the heating hood is too short or the temperature is too low, the spinneret will be cold, resulting in poor spinning properties.On the other hand, if the length of the heating hood is too long or the temperature is too high,
The spinneret surface becomes extremely dirty and energy is wasted.

The yarn passed through the heating hood is usually cooled and solidified in a water cooling tower at 50 to 80°C, and taken off at a speed of 20 to 2000 m/win, preferably 50 to 1000 m/tain.

The undrawn monofilament thus obtained is then drawn either after being wound up or continuously after being taken up.

Stretching is usually carried out in a first stage of stretching at a stretching ratio of 1.5 to 2.7 in an air bath or heat medium bath at a temperature above the glass transition point and below 230°C, and then at a temperature lower than the temperature of the first stage stretching. The total stretching a ratio is 2.5 to 6.0 at a temperature that is 30°C or more higher and lower than the melting point of the monofilament. Preferably, this is carried out by a method of second-stage stretching so that the stretching angle is 3.0 to 5.0.

After stretching, heat treatment is performed as necessary.

Note that the measurement method in the present invention is as follows.

1JfJ! J! J! Watari After conditioning the sample at 20° C. and 65% R11 for 24 hours.

Autograph DSS-500 manufactured by Shimajiru Seisakusho was used.

Measurement was performed with a sample length of 25 cm and a tensile speed of 30 cm/min.

-Young Dormitory It was determined from the initial slope of the load-elongation curve during the above-mentioned strength elongation measurement.

(Example) The present invention will be explained in more detail below with reference to Examples.

EXAMPLE A monofilament was manufactured using PEEK having an intrinsic viscosity of 1.1 in the following manner.

Using a regular extruder type melt spinning device.

A heating hood with an inner diameter of 60mm, a length of 100mm, and an ambient temperature of 250°C was installed directly below the spinneret, and the spinning temperature was set at 400°C.
C.

The residence time was 10 minutes or less, the spinning was carried out through a spinneret having a diameter of 1.5 as and a length of 3 mm, and the spinneret was cooled by being introduced into a water cooling tower at 70°C.
The monofilament was wound up at a speed of min to obtain an undrawn monofilament.

The obtained undrawn monofilament was drawn in two stages at various magnifications and temperatures to obtain a monofilament having a diameter of 0.3 u+ (830 denyl).

Table 1 shows the characteristic values of the drawn monofilament obtained.

Table 1 (Effects of the Invention) According to the present invention, it is made of a polyetherketone polymer having excellent heat resistance, chemical resistance, abrasion resistance, etc.

A monofilament is provided that has properties suitable for use in abrasive brushes.

Claims (1)

[Claims] (1) A monofilament consisting essentially of aromatic polyetherketone, with a strength of 3 g/d or more and an elongation of 2
A monofilament for an abrasive brush, characterized in that it has an initial Young's modulus of 0 to 50% and an initial Young's modulus of 40 to 80 g/d.