JPS60252715A - Monofilament for abrasion - Google Patents

Abstract

PURPOSE:The titled monofilament that is produced by adding a specific amount of polyester elastomer to polybutylene terephthalate as a base polymer, combining the mixture with abrasive particles and extruding the composition into fiber, thus showing good abrasion, high toughness, water resistance, chemical resistance and flexural resistance. CONSTITUTION:A mixture of (A) 50-90pts.wt. of polybutylene terephthalate having a melt viscosity of more than 5,000ps, preferably less than 25,000ps with (B) 50-10pts.wt. of polyester elastomer is combined with 10-50wt% of abrasive particles such as coke powder and the resultant composition is melt-extruded into the objective monofilament. Component B is a polyester block copolymer composed of 15-90% of normal polyester hard segment and 85-10% of polyether soft segment of number-average molecular weight of 200-6,000.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This invention relates to a polishing monofilament that exhibits excellent effects in polishing applications such as (industrial application).

(Conventional technology) Traditionally, it has been used in fields such as industrial brushes.

It is well known that monofilaments obtained from synthetic resins containing abrasive particles are used, and polyamides such as nylon 6, nylon 66, and nylon 12, which have excellent toughness and spinnability, are mainly used as materials for this abrasive monofilament. Applied. However, when using an industrial brush to polish, for example, a metal surface, water or an acidic liquid is usually poured onto the polished surface in order to remove the heat generated by polishing and to keep the polished surface clean. Polishing monofilament, which is mainly made of polyamide, swells or becomes soft due to water absorption and loses its toughness when it is used in wet conditions. There is a problem that the durability life is likely to be adversely affected by exposure to heat. Therefore, when using abrasive monofilament mainly made of polyamide in a wet state, it is necessary to take measures that go against energy conservation and brush durability, such as increasing the number of rotations of the brush or increasing the pressing force. In this case, it is necessary to adjust the bristles and operating conditions of the brush according to swelling and contraction of the brush, making the work extremely complicated.

On the other hand, polyester has better water resistance than polyamide, and it is expected that the above-mentioned drawbacks of polyamide monofilament can be overcome by applying it to polishing monofilaments. However, polyethylene terephthalate, which is a typical polyester, has a high polybutylene terephthalate has a lower rigidity than polyethylene terephthalate, and while it has excellent brush properties, there are problems with the melt-spinning properties of the mixture with abrasive particles. Furthermore, there is a problem that the monofilament has poor bending resistance and grinding properties.

The inventors of the present invention conducted studies aimed at developing a polyester monofilament for polishing that eliminates these drawbacks, and found that
Polybutylene terephthalate having a specific high melt viscosity is used as the base resin, and a monofilament made by containing a specific amount of polyamide and abrasive particles has excellent abrasive properties, toughness, water resistance, bending resistance, and durability. It was proposed to the target that it had drug properties (patent application filed in 1973).
No. 8-97880). However, subsequent studies have shown that there is still room for improvement in the bending fatigue resistance of abrasive monofilaments made of polyethylene terephthalate as a base resin. It has been found that the root part of the flocked hair becomes brittle and tends to break easily at this part. This problem in bending fatigue resistance becomes more pronounced as the brush grinding conditions become more severe, and can be said to be a major defect as an industrial brush material.

(Problems to be Solved by the Invention) Therefore, the inventors of the present invention continued to study further in order to improve the bending fatigue resistance of the abrasive monofilament made from the polygutter wrench V phthalate base resin. As a result, by using a polyester elastomer instead of the above-mentioned polyamide as the other resin blended with the base resin polybutylene terephthalate, the above-mentioned excellent performance is maintained, and the bending fatigue resistance is extremely improved, as well as the yarn-spinning property. It was discovered that an improved top filament for polishing can be obtained, and the present invention was achieved.

(Means for Solving the Problems) That is, the present invention further comprises adding abrasive particles to a mixture consisting of 50 to 90 parts by weight of polybutylene terephthalate and 50 to 10 parts by weight of polyester elastomer having a melt viscosity of 0,000 Boices or more. Contains 10 to 50% by weight,
An abrasive monofilament made by melt-spinning this is provided.

Polybutylene terephthalate (hereinafter FB) used in the present invention
It is abbreviated as 'l'. ) is essentially a polyester obtained by esterifying or transesterifying terephthalic acid or its ester-forming derivative with 1,4-butanediol or its ester-forming derivative, followed by polycondensation. If the proportion is high, other dicarboxylic acids such as isophthalic acid, phthalic acid, natu- dicarboxylic acid, adipic acid, sebacic acid, ethylene glycol, etc.
Propylene glycol/I/, neopentyl glycol,
It may contain other diols such as cyclohexane diol and polyalkylene glycol.

In addition, the PBT used is a heat stabilizer, antioxidant, weathering agent,
It may contain conventional additives such as colorants, lubricants, flame retardants and antistatic agents.

Generally, when PBT is melt-spun into monofilament, a relatively low-viscosity polymer with a melt viscosity of 5,00 oJ is used.
When melt spinning is performed with abrasive particles contained, the outflow state of the molten polymer discharged from the spinning nozzle becomes unstable as described above, causing diaphragm and thread breakage, making it impossible to perform stable melt spinning. However, in the present invention, the melt viscosity is s
, o o o boys and above, especially aoo.

It is characterized by the use of PBT with a high viscosity that far exceeds the standards for so-called melt spinning, which is higher than Boise, and this improves the affinity between the abrasive particles and the polymer, making it possible to use adhesives. Monofilament having excellent grinding and abrasive power can be stably and efficiently melt-spun without any process.

Although there is no particular limit to the upper limit of the melt viscosity of PBT used in the present invention, the upper limit of the melt viscosity of PBT obtained by solid state polymerization is generally about 30,000 voices, and 25. If this happens, melt spinning becomes difficult.
It is preferable to use a material having 000 voids or less.

In addition, the melt viscosity as used in the present invention is measured using a Koka type flow tester, pressure 20 kg/Iff'', mouth diameter a, s+m%.
This is a value measured at a temperature of 240 to 250°C.

On the other hand, the polyester elastomer used in the present invention includes a polyester hard segment and a number average molecular weight of about 200 to
000 polyester soft segment: 1'. A, 1 go, 1 ah...
2, -, discoloration 724. The ratio of raft segments is 15~
90% by weight versus 85-10% by weight. Examples of the carbonic acid component forming the polyester hard segment include terephthalic acid, isophthalic acid, phthalic acid, 2.6
- and 1,5-naphthalene dicarboxylic acid, bis(p-
Carboxyphenylene/I/) methane, anthocenedicarboxylic acid + aromatic dicarboxylic acid such as 4.4'-diphenyletherdicarboxylic acid + 1.4-cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, 4.4'-dicyclohexyl Examples include alicyclic dicarboxylic acids such as dicarboxylic acids, and aliphatic dicarboxylic acids such as adipic acid, sepacic acid, azelaic acid, and dimic acid.2 At least 50 mol% or more is aromatic in terms of mechanical properties and heat resistance. Preference is given to using dicarboxylic acids, and in particular terephthalic acid is recommended.

The diol components constituting the hard segment include aliphatic or alicyclic diols having 2 to 12 carbon atoms, ie, ethylene glycol, propylene glycol, 1.
4-butanediol, neopentylglyco-y, I, 5
-pentanedio-A/, +, 6-hexanediol, decamethylene glycol, cyclohexane dimetatool, C bis(p-hydroxy)diphenyl, bis(p-hydroxypheni/I/)methane, bis(p-hydroxyphenyl) Although bisphenols such as globan and mixtures thereof can be used, aliphatic or alicyclic diols having 2 to 8 carbon atoms are particularly preferably used. .

The poly(alkylene oxide) glycols constituting the polyether soft segment include polyethylene glycol, poly(1,3- and 1,2-propylene) glycol, poly(tetramethylene oxide) glycol,
These include polyethylene glyco-μm polypropylene glycol block copolymer, polyethylene glyco-μm poly(tetramethylene oxide) glycol random copolymer, etc., and poly(tetramethylene oxide) glycol is particularly preferred, and of course a combination of these is also possible. The number average molecular weight of these ether glycols is approximately '2
It ranges from 0G to 4000.

Among the above polyester elamethomers, those consisting of mototerephthalic acid, 1,4-butanediol and poly(tetramethylene oxide) glycol having a number average molecular weight of about 300 to 6,000 can be preferably used.

Although there is no particular restriction on the melt viscosity of the polyester elastomer, it is particularly desirable to use a melt viscosity of t,oooyg or higher.

A suitable mixing ratio of the above PBT and polyester elastomer is 50 to 90 parts by weight, especially 70 to 90 parts by weight for the former, 50 to 50 parts by weight for the latter, and especially 30 to 10 parts by weight (total 100 parts by weight). If the polyester elastomer is less than 10 parts by weight, the bending fatigue resistance of the polishing monofilament cannot be sufficiently improved, and if it exceeds 50 parts by weight, the water resistance, chemical resistance, toughness, etc. of the polishing monofilament will be impaired. Undesirable.

The abrasive particles used in the present invention are coke powder.

Alumina-based abrasives such as bauxite and alumina powder, silicon carbide-based abrasives such as white silica and mineral powder, natural product-based abrasives such as diamond, emery, and garnet, carbide-based abrasives, zirconia-based abrasives, and Examples include glass-based materials and abrasives.

Two or more of these can be used in combination. The particle size of these abrasive particles is preferably in the range of 60 to +5OO1, especially 80 to 800, as defined in J.K. 5R600+ (1956). If the toughness is less than +500, the abrasiveness may decrease, which is not preferable.

In the present invention, the amount of abrasive particles added is suitably 10 to 50% by weight, especially 15 to 40% by weight, based on the mixture of PBT and polyester elastomer; if it is less than 10% by weight, the desired abrasive effect cannot be obtained; Exceeding this percentage by weight is not preferable because the toughness and melt spinnability of the monofilament deteriorate.

There are no particular restrictions on the method for preparing a composition consisting of PBT, polyester elastomer, and abrasive particles, such as tri-blending all the ingredients at once, or adding abrasive particles to a mixture of PET and polyester elastomer. Examples include a method of mixing the mixture and applying it to an extruder to obtain pellets, or a method of directly forming monofilaments without pelletizing.

Melt-spinning of monofilaments can be carried out in the same way as the usual melt-extrusion spinning method for polyester, with extremely good spinning properties, and the monofilaments after melt-spinning can be appropriately stretched and heat-set to impart further toughness. It is also possible to do so.

There is no limit to the diameter of the abrasive monofilament of the present invention made by straining as described above, and it can be freely selected by changing the diameter of the spinneret or setting the drawing conditions depending on the use of the monofilament. is about 0.2 to 2.0
A range of 111 is appropriate. Furthermore, compared to conventional monofilaments made of polyamide and abrasive particles, the polishing monofilament of the present invention has the same bending hardness even if it has a smaller diameter, so it can be made thinner than conventional monofilaments, making it easier to use when using a brush. Not only is it economical because the pressing force and rotational speed can be reduced, but it also has the advantage that the polished surface can be finished finely.

The effects of the present invention will be explained in more detail below with reference to Examples.

(Example 1) Melt viscosity 650017) PBT (Toshiku Co., Ltd.) CM+
200) and the following two types of polyester elastomer A
, B were mixed in the proportions shown in Table 1, and in addition, 20% by weight of alumina oxide abrasive (Showa Denko Co., Ltd. Ii!, Chemical Random A-40) with a particle size of 100 was added as abrasive particles. Tri blended.

Block copolymer of polyester elastomer A to PBT6G and 40 parts by weight of poly(tetramethylene oxide) glyco-1v having a molecular weight of +400 (melt viscosity, +200) Polyester elastomer B+-23180 parts by weight and poly(tetramethylene oxide) having a molecular weight of 1000 Block copolymer with 20 parts by weight of glycol (melt viscosity, +000) Next, the above mixture was melt-mixed using a φ40 stage melt extruder, and the resin temperature was 270°C and the extrusion pressure was 20 kg/lx.
', spun from a nozzle at a discharge rate of 10,061 min, cooled and assimilated in a cooling water bath at room temperature, taken up at a speed of 35 m/min, and stretched approximately 50 times in a hot air circulation bath at 120°C; Furthermore, it was passed through a hot air circulation bath at 150° C. for 5 seconds and heat-fixed to obtain a monofilament containing abrasive particles having a diameter α of 55 gm.

Table 1 shows the results of evaluating the following properties of the obtained monofilament.

(1) When a monofitment with a length of 501o+ is placed between the two prongs of the bending hardness interval + Ogm and a pullout load is applied to the central part of the monofit, the maximum load when the sample curves and passes between the fulcrums. value.

(Drying)...24 in an atmosphere of 20℃ and 65% humidity.
Measurement after standing for a period of time (wet): Measurement after immersing a dry sample in water at room temperature for 24 hours (2) Bending recovery rate Monofilament bent 360 degrees.・Measure the recovery angle (′
g on this load side at a bending angle of 260 degrees 180 times/
After making a reciprocating motion for a minute, the fixed mole beak '4'''''y) Cut the root xyl part 7'! ″″″′Back and forth 1′ Measure the number of movements.

(4) Create a brush with an outer diameter of 270 by implanting 3.5W monofilament into Gufunlo /I/ with a grinding force width of 200m,
Using this, the grinding amount (μ) of the iron plate surface is measured when the surface of the iron plate (ss41) is ground for 5 minutes under the conditions of lap amount 3M, 900 r, p, m, and hot water injection.

(5) Stretchability The maximum stretchable monofilament diameter (φ) when producing a monofilament stretched 50 times in a hot air circulating bath at 120°C is shown. (The larger the number, the larger the applicable range of stretching, and the better the stretching property.) It is clear from the results in Table 1 that the monofilament (Cliff 1) made of YogukopBT/abrasive particles has excellent grinding properties, but it is resistant to bending. Poor fatigue properties.

However, the polishing monofilament of the present invention (graves 5 to 6), which is made of a composition in which a specific amount of polyester elastomer is blended together with abrasive particles, has A1 and p
Monofilament consisting of BT/nylon 6/abrasive particles)
(A2) Compared to C, bending hardness, water resistance, bending recovery rate, bending fatigue resistance, grinding force, and stretchability are well balanced, and among them, the effect of improving bending fatigue resistance is remarkable.

However, if the blending amount of polyester efstomer exceeds 50 parts by weight, the rigidity will decrease and the rigidity will decrease.
If the amount is less than part by weight (cliff 7), the bending fatigue resistance cannot be sufficiently improved.

(Example 2) A rotating brush was made by bundling 150 f4 monofilaments obtained in Example 1, and it was rotated at a rotation speed of 1000 times/minute and applied to the surface of a rusted iron plate while pouring water onto the polished surface. As a result of pressing and polishing, a beautiful mirror-like polished surface could be obtained, and the brush was extremely durable. (Effects of the Invention) The abrasive monofilament of the present invention obtained by stable and efficient melt spinning is strong and does not expand or contract due to water absorption, and has extremely excellent abrasiveness, grinding force, bending fatigue resistance, and yarn spinning properties. There is.

Therefore, the abrasive monofilament of the present invention can be made into a brush by bundling, implanting, gluing, entangling, etc., and can be applied to metal, painted surfaces, and wood.

It is used in industrial plans for polishing and grinding surfaces such as stone and concrete, as well as general household punches such as kitchen utensils, and is characterized by excellent effects.

Claims (1)

[Claims] A mixture of 50 to 90 parts by weight of polybutylene terephthalate and 50 to 10 parts by weight of polyester elastomer having a melt viscosity of 5.0.00 poise or more is further added with 10 to 50 parts by weight of abrasive particles, and this is melt-spun. Monofilament for polishing.