JPS6352973A - Bristles for polishing brush - Google Patents

Abstract

PURPOSE:To aim at enhancing the polishing ability, a heat resistance, chemical resistance and durability of bristles for a polishing brush, by using monofilaments which are formed by spinning a molten material which is composed of substantially linear polyphenylene sulfide having a melt flow rate of less than 200, and a predetermined weight percent of abrasive particles having a predetermined grain size, contained in the former. CONSTITUTION:As bristles for polishing brushes adapted to polish metal and wood materials, there are used filaments which are formed by spinning such a molten material that 5 to 40 weight percent, preferably 10 to 30 weight percent of abrasive particles having a grain size of #1,500 to #60 is contained in polyphenylene sulfide which is linear polymer including substantially no cross- linked components and having a melt flow rate of less than 200, preferable less than 180. The above-mentioned abrasive particles is made of coke powder, polishing agent of almina group, silicon carbide group, natural product group, cabrbonized material group, zirconia group, glass group or the like. Thus, bend recovery, polishing ability, heat resistance, chemical resistance and durability of the bristles are may be made to be uniform and excellent.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a bristle material for polishing brushes suitable for polishing the surfaces of metals, wood, etc. under particularly harsh conditions. Bending recovery, polishability, heat resistance,
This invention relates to a bristle material for abrasive brushes that has excellent chemical resistance and durability.

(Prior art) Traditionally, in the field of industrial brushes for grinding and polishing,
It is well known that monofilaments made of synthetic resin containing abrasive particles are used as bristle materials for brushes. As the synthetic resin material for this brush bristle material, polyamides such as nylon 6, nylon 66, or nylon 612, and polyesters such as polybutylene terephthalate have been mainly used.

(Problems to be Solved by the Invention) When these industrial brushes are put to practical use, it is necessary to diffuse the frictional heat generated during the grinding and polishing process to prevent heat accumulation and to normalize the grinding and polishing surfaces. In most cases, liquids such as water, hot water, various emulsions, and weakly acidic or slightly alkaline liquids are sprayed onto the areas where the brush comes into contact with the grinding or polishing surface. The wood will be placed under moist conditions.

In addition, in the grinding and polishing process mentioned above, the diffusion of frictional heat is still insufficient, so the temperature of the polishing surface and the brush part in contact with it becomes considerably high. In order to increase the temperature, the above temperature must be set higher and higher.

However, under such operating conditions, the nylon 6
Conventional polishing monofilaments made of polyamide such as nylon 66 or nylon 612 containing abrasive particles swell due to moisture absorption and become extremely soft.
As the stiffness of the bristle material weakens, it also becomes more abrasive, which inevitably reduces the grinding and polishing power, and also creates unevenness on the brush surface, making it impossible to achieve uniform grinding and polishing effects.

Furthermore, polishing monofilament made from polybutylene terephthalate is not inherently hygroscopic, so although it maintains its hardness during operation, it suffers from bending fatigue due to the continuous repetition of bending and recovery of the bristles, that is, its bending recovery properties are poor. For,
During operation, the monofilament tends to break at the bend in a relatively short time, which is an undesirable phenomenon.

Therefore, the present inventors conducted extensive research with the aim of obtaining a bristle material for polishing brushes that has a good balance of abrasiveness, heat resistance, chemical resistance, and durability, and is suitable for polishing work under particularly harsh conditions. The inventors have discovered that by using polyphenylene sulfide having a specific viscosity as a synthetic resin material, an industrial brush bristle material that satisfactorily meets the above objectives can be obtained, and the present invention has been achieved.

(Means for Solving the Problems) That is, the present invention has a melt flow rate of 200 or less and a substantially linear polyphenylene sulfide, and abrasive particles having a particle size of R1500 to #60 are added to
The object of the present invention is to provide a bristle material for an abrasive brush characterized by comprising a monofilament containing 40% by weight of bristle material and melt-spun from the monofilament.

The polyphenylene sulfide polymer used in the method of the present invention is basically produced by the method described in Japanese Patent Publication No. 52-12240, and 80 mol% or more of the constituent units are p-phenylene sulfide units. Consisting of
The copolymerization component can be contained in a proportion of 20 mol% or less. In addition, polyphenylene sulfide can be blended with other thermoplastic polymers in small proportions, and may further include heat-resistant agents, light-resistant agents, weather-resistant agents, antistatic agents, plasticizers, lubricants, flame retardants, It may contain conventional additives such as dyes and pigments.

However, the polyphenylene sulfide polymer used in the present invention is a linear high polymer substantially free of crosslinking components, and has a melt flow rate (hereinafter referred to as M
FR) is required to be in the range of 200 or less, particularly 180 or less.

If the polyphenylene sulfide polymer is branched or cross-linked with a cross-linking component such as trichlorobenzene, the spinning state may become uneven and breakage may occur during drawing, resulting in unstable spinning. Not only does the flexibility of the monofilament decrease, but the bending recovery of the monofilament also decreases.
Further, when the VFR exceeds 200, the degree of polymerization of the polymer is low and it is not possible to obtain a monofilament that is uniform and has sufficient strength, which is not preferable.

The abrasive particles used in the present invention include alumina-based abrasives such as coke powder, bauxite, and alumina powder, carbide silica-based abrasives such as white silica and nail powder, and natural abrasives such as diamond, emery, and garnet. Examples include abrasives, carbide-based abrasives, zirconia-based abrasives, and glass-based abrasives, and two or more of these can be used in combination. The particle diameter of these abrasive particles is JIS R6001 (195
The particle size specified in 6) is R1500 to R60, especially R
A particle size in the range of #1300 to #80 is preferable, and if the particle size is larger than R60, the spinnability and toughness of the monofilament will deteriorate, and if it is smaller than R1500, the abrasiveness will deteriorate, which is not preferable.

The blending amount of the abrasive particles with respect to polyphenylene sulfide is preferably in the range of 5 to 401%, particularly 10 to 30% by weight, and if it is less than 5% by weight, desired grinding and abrasive properties cannot be obtained, and 40% by weight. Exceeding this is undesirable because it leads to increased monofilament diameter variation, decreased strength, and reduced stiffness.

Melt spinning of the bristle material for abrasive brushes (monofilament containing abrasive particles) of the present invention can be carried out by, for example, adding abrasive particles to polyphenylene sulphide, melt-mixing the mixture, and then -H pelletizing. Alternatively, it can be obtained by directly applying it to a melt extrusion spinning hall without pelletizing, spinning it out from a spinneret, cooling it, and stretching it if necessary.

Specifically, a mixture of polyphenylene sulfide and abrasive particles is heated to a temperature 10 to 60° C. higher than the melting point of the normal polymer, and then melt-extruded and spun.

Next, it is desirable to cool and solidify the melt-spun yarn in hot water of 60°C or higher; if the cooling temperature is lower than 60°C,
If the cooling rate is too fast, the running of the yarn becomes unstable, uniform stretching is impossible, and the strength level of the obtained monofilament is also lowered, which is not preferable.

Note that the holding time of the yarn after it is melt-extruded from the spinneret until it reaches the hot water bath at 60° C. or higher is usually within 2 seconds, but it is particularly preferable to set it to 0.1 to 1.0 seconds. be.

Subsequently, the obtained undrawn monofilament is usually drawn at a temperature higher than its glass transition point temperature, but multi-step drawing of two or more steps is preferable, and the total drawing ratio is 3.
A range of ~5 times is suitable.

As the stretching atmosphere, a warm water bath, an air bath, a steam bath, etc. are suitably used.

The drawn monofilament must be subjected to a heat treatment to further improve the strength level, which heat treatment may be carried out at temperatures between 150 and 280'C, particularly between 200 and 270'C.
It is important to do this in a relaxed state in an air bath.

If the heat treatment temperature is less than 150°C, a monofilament with high strength cannot be obtained, and if it exceeds 280°C, thread breakage is likely to occur, and the strength of the monofilament will actually decrease, which is not preferable.

Further, the heat treatment must be carried out in a relaxed state with a winding ratio of 0.95 times or less, and heat treatment under tension is not preferable because the strength of the obtained monofilament is significantly reduced.

Here, the cross-sectional shape of the monofilament single yarn containing abrasive particles can be oval, triangular, rectangular, or other irregular shapes other than circular, and the average diameter thereof is usually 0.2 to
A range of 2.5 m is preferred. If the diameter of the monofilament is less than 0.2 rNn, it is not preferable to cause yarn breakage, and the polishing effect is also small, and if it exceeds 2.5, the monofilament itself becomes brittle and easily breaks, which is not preferable.

The polishing brush bristle material of the present invention thus obtained is cut to a desired length, formed into a brush shape by bundling, implanting, gluing, intertwining, etc., and then hung into a rotating or reciprocating brush or a sash. It is preferably applied to industrial grinding and polishing means for surfaces such as metal, painted surfaces, wood and concrete, such as passing a non-abrasive object under it, but also as a household brush for kitchen utensils etc. It can be used effectively.

The polishing brush bristle material of the present invention has the ability to sufficiently maintain its properties even when exposed to particularly harsh polishing conditions, and for example, it can remove scale attached to work rolls in a cold rolling line for steel plates. In polishing work, 5~
10% acid (hydrochloric acid) or alkali (caustic soda)
Even when the brush is operated in a high-temperature atmosphere of about 60 to 80° C. while spraying, its polishing properties and durability are very good.

EXAMPLES The effects of the present invention will be briefly described below with reference to Examples.

(Example-1) The following three types of polymer A as polyphenylene sulfide
, B and C prepared MFR crosslinking component (TCB%) Polymer △-1...130 0 Polymer A-2
・・・・・・170 0 Polymer A-3・・・・・・
150 0.2 On the other hand, the following two types of abrasive particles were prepared.

Grinding B-1...Silicone carbide abrasive particles C-180 (#180) made by Showa Denko ■ Grinding B-2...Alumina abrasive particles A- made by Showa Denko ■ 40 (#320) 23% by weight of each of the above abrasive particles was mixed with the above polymer, and each was subjected to an extruder of 40 sψ, and the extrusion temperature was 300.
Melt-spun from the spinneret at 'C, and 60
After quenching in a hot water bath at 160'C, 4.
It was stretched 5 times.

The drawn monofilament was then heat-treated in an air bath at 250° C. at a take-up ratio of 0.90 times, and then wound up to obtain three kinds of abrasive particle-containing polyphenylene sulfide monofilaments each having a diameter of 0.7 trm.

Table 1 shows the results of evaluating the number of times of bending fatigue and the number of thread breakages during spinning and drawing for each of the obtained monofilaments 1 to 1.
Shown below.

The monofilament was evaluated according to the following method.

(Bending fatigue resistance) Fix one end of the hair material with a length of 10 cm, apply a load of 'I Kl in the vertical direction of the other end, and bend the other end at a speed of 180 times/min so that the bending angle is 90°. When the hair material is bent repeatedly, the number of bends (times) until the hair material breaks is read.

(Number of thread breaks during spinning and drawing) Monofilament 1. The value converted per OKg to the number of yarn breakages during spinning and drawing.

As is clear from the results in Table 1, the bristles for polishing brushes of the present invention (Nα1 to 4) have a high bending fatigue count and are excellent in spinning and drawing properties.

On the other hand, those made of polyphenylene sulfide containing a crosslinking component (Nα5 and 6) have a low number of bending fatigues and have many yarn breakages during spinning and drawing.

(Example 2) The monofilaments of Nα1 and 3 obtained in Example 1 were
50 meters of condolence letters were used as brush bristle material, and this amount was 300 meters.
A disc-shaped rotating brush was created by bundling the hair and planting it on a base of 300 mφ x 400 sL, and used it as a cleaning solution at 85°C under the conditions of a brush rotation speed of 1000 times/min and a pressing pressure of '1.5 to 3/cm. The surface of a 95HS work roll in an aluminum rolling operation was polished while pouring a 10% hydrochloric acid aqueous solution or an 8% caustic soda aqueous solution.

As a result, the rotating brush made of the bristle material for polishing brushes of the present invention operated normally for 10 consecutive days no matter which cleaning solution was used, and exhibited excellent polishing power without causing any wear or breakage of the brush. .

On the other hand, for comparison, Showa Denko Aji's silicon carbide abrasive particles C-
A 0.7 #71 diameter nylon 6 monofilament and a polybutylene terephthalate monofilament each containing 23 wt. As a result, in the case of nylon 6 monofilament, when a 10% hydrochloric acid aqueous solution at 85°C was used as the cleaning solution, the grinding force decreased two days after the start of operation, causing some breakage of the bristles, while in the case of polybutylene terephthalate monofilament, When an 8% aqueous solution of caustic soda at 85°C was used as the cleaning liquid, the grinding force decreased significantly and the bristles began to break 2.5 days after the start of operation.

(Effects of the Invention) As explained above, the bristle material for abrasive brushes of the present invention has an excellent balance of bending recovery properties, abrasive properties, heat resistance, chemical resistance, and durability, and is particularly suitable for polishing under harsh conditions. work to do,
For example, it is extremely useful for brush applications such as grinding and polishing the surface of iron plates in steel manufacturing and cold rolling processes, grinding and polishing work roll surfaces in aluminum and rolling processes, and deburring and polishing machine parts.

Claims (1)

[Claims] For polyphenylene sulfide that has a melt flow rate of 200 or less and is substantially linear, the particle size is #
A bristle material for an abrasive brush comprising a monofilament containing 5 to 40% by weight of abrasive particles of #1500 to #60 and formed by melt-spinning the same.