JPH02202548A - Polyphenylene sulfide resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition capable of extremely reducing wear of object material, low specific gravity and excellent mechanical properties by blending polyphenylene sulfide with both potassium titanate fiber and aramid fiber in a specific ratio. CONSTITUTION:100 pts.wt. composition comprising (A) 30-90wt.% polyphenylene sulfide, (B) 3-50wt.% aramid fiber and (C) 3-40 wt.% potassium titanate fiber is blended with (D) 0-40 pts.wt. lubricant. Poly p-phenylene terephthalamide fiber, etc., having 1-15mm fiber length is used as the component B. A polyphenylene sulfide resin having 5-100mu average length, <=1/mu average diameter and >=10 aspect ratio is used as the component C.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a polyphenylene sulfide resin composition that has excellent abrasion resistance, is lightweight, and has excellent AM properties.

<Prior art> Polyphenylene sulfide resin (hereinafter abbreviated as PPS resin) is known as an engineering plastic with excellent heat resistance, chemical resistance, flammability, and dimensional stability, and is used in electrical and electronic parts, Widely used in fields such as automobile parts and films.

In recent years, PP has also been used for sliding applications such as bearings and gears.
S-resin sliding materials are attracting attention and demand is increasing.

Since PPS resin alone is extremely brittle, PPS sliding materials containing reinforcing materials such as glass fibers or carbon fibers and lubricants have been sold as molding compounds.

However, when glass a-fiber or carbon fiber is used as a reinforcing material, although the mechanical strength is improved, there is a problem in that the material to which the PPS resin is attached is subject to severe wear. In addition, pps1! contains only lubricant! Although the IJ resin composition can significantly reduce the wear of the mating material, there is a problem in that it is brittle and cannot withstand large mechanical loads.

Therefore, as a means to solve such problems, P l
) Resin compositions in which potassium titanate fibers are melt-blended with S resin (JP-A-59-215353) and resin compositions in which aramid fibers are melt-blended (JP-A-63-162727) are known. ing.

<Problems to be Solved by the Invention> However, the potassium titanate fibers disclosed in the above-mentioned conventional examples serve as reinforcing materials, and Ppsv! Although it has the effect of improving the mechanical strength of the resin and reducing the wear of the mating material, the wear reduction effect was insufficient when the mating material was a material with low hardness such as an aluminum alloy.

In addition, potassium titanate fiber has a high specific gravity of approximately 3°5, so PP5v! If a large amount is added to J fat, the specific gravity of the molded product becomes large, which limits its use as a sliding material.

On the other hand, the eta composition containing aramid fiber can significantly reduce wear even when the mating material is a material with low hardness such as an aluminum alloy, and has the advantage that the specific gravity of the molded product containing a large number of fibers is small. However, there was a problem in that a molded product with sufficient strength could not be obtained.

Therefore, an object of the present invention is to solve the problems that conventional ppsvA fat compositions have.

Therefore, an object of the present invention is to obtain a polyphenylene sulfide resin composition that can significantly reduce wear of a mating material, has a low specific gravity, and has excellent mechanical properties.

<Means for Solving the Problems> As a result of intensive studies to achieve the above object, the present inventors combined a specific proportion of potassium titanate fibers and aramid fibers with polyphenylene sulfide resin, and By adding a lubricant accordingly, ppst! meets the above objectives and has the desired balance of physical properties. The inventors have discovered that a fat composition can be obtained, and have arrived at the present invention.

That is, the present invention provides (a) polyphenylene sulfide 3
0 to 40 parts by weight of a lubricant to 100 parts by weight of a resin composition consisting of 0 to 90% by weight, (b) 3 to 50% by weight of aramid fibers, and (c) 3 to 40% by weight of potassium titanate fibers. The present invention provides a PPS resin composition comprising:

The PPS resin used in the present invention has a repeating unit represented by the structural formula +S) of 70 mol% or more, more preferably 90 mol% or more.
It is a polymer containing mol% or more of the above repeating unit, and if the content of the above repeating unit is less than 70 mol%, it is not preferable because the thermal properties are impaired.

Furthermore, less than 30 mol% of the repeating units in the PPS resin can be composed of repeating units having the following structural formula.

ppsw fat general 2, a polymer with a relatively small molecular weight obtained by the production method typified by Japanese Patent Publication No. 45-3368, and an essentially polymer obtained by the production method typified by Japanese Patent Publication No. 52-12240. There are linear polymers with relatively high molecular weight, and in the polymer obtained by the method described in the above-mentioned Japanese Patent Publication No. 45-3368, polymerization is carried out by heating in an oxygen atmosphere or by peroxidation. It is also possible to increase the degree of polymerization and use it by adding a crosslinking agent such as PPS resin and heating, and in the present invention, it is possible to use a PPS resin obtained by any method.

The aramid fiber used in the present invention is a fiber made of a polymer synthesized by polycondensation of an aromatic diamine and an aromatic dicarboxylic acid or a derivative thereof. Among these, polyvaraphenylene terephthalamide fibers and polymetaphenylene isophthalamide fibers are most preferred.

There is no particular restriction on the average fiber length of the aramid fibers, but the average fiber length is between 1 and
Preferably, the area covers 15 cities.

The amount of aramid fiber blended is 3 to 50% by weight, preferably 5% by weight.
-40% by weight.

If the blending amount is less than 3% by weight, the effect of reducing wear on the mating material will be small, and 50! If it exceeds Ji%, the dispersibility of the aramid fibers will decrease and the strength of the composition will decrease significantly, which is not preferable.

The potassium titanate fiber used in the present invention is a single crystal 1I made of potassium titanate represented by the following formulas I and .
It is fiber.

K20-n (Ti02)-4
20-n<TlO2>-1/2H20-n (in the formula, n
is an integer from 2 to 8) Specifically, it is a single composition and/or a mixture of potassium titanate fibers, potassium hexatitanate fibers, or potassium octatitanate fibers, and has an average fiber length of 5 to 100μ.
, an average IgI fiber diameter of 1 μ or less and an average fiber length/average fiber diameter (aspect ratio) of 10 or more can be used.

The blendability of the potassium titanate fibers is selected in the range of 3 to 40% by weight, preferably 5 to 35% by weight. The blending amount is 3
If it is less than 4% by weight, the effect of improving mechanical strength is small;
When the content is 0% or more, the specific gravity of the composition increases, and
This is undesirable because wear of the mating material becomes obvious.

The lubricant used in the present invention provides a lubricating effect to the resin composition of the present invention comprising a PPS resin, an aramid fiber, and a potassium titanate fiber within a range that does not impair its purpose.

Specific lubricants include, for example, polytetrafluoroethylene (hereinafter abbreviated as PTFB) powder, polyethylene powder, graphite powder 1, silicone and molybdenum disulfide powder, which may be used alone or in combination of two or more. Can be used in combination.

The blending amount of the lubricant is preferably less than 40% by weight, preferably less than 35% by weight, based on 100 parts by weight of the resin composition consisting of PP5vA fat, aramid fiber, and potassium titanate fiber, and if it is 40% by weight or more, R This is not preferable because mechanical strength decreases and practicality decreases.

The composition of the present invention may be produced by a method such as boat fishing, for example, mixing the components together at room temperature using a ribbon blade type mixer or a drum type rotary mixer. WA can be manufactured by melt-kneading the mixture using a single-screw extruder or kneader, and pelletizing it.

The melting and kneading temperature is PP5v! In order to sufficiently melt J resin, the temperature is preferably 280° C. or higher, and 340° C. or lower from the viewpoint of preventing thermal deterioration and gelation of the PPS resin.

The composition of the present invention may further contain antioxidants, heat stabilizers, lubricants, colorants, ultraviolet absorbers, various polymers, and the like within a range that does not impede the object of the present invention.

<Example> Hereinafter, the present invention will be specifically explained with reference to Examples.

Note that parts in the examples are based on weight.

Characteristic evaluations in this example were carried out in accordance with the following methods.

Tensile strength: ASTM-D638 Bending strength: ASTM-D790 Bending modulus: ASTM-D790 Izot impact strength: ASTM-D 256 Friction coefficient: Precious wood type abrasion tester Load 30 kgf/cd Speed 30 m/min Mating material SCM21 Mating Evaluation of agent damage: load 15krf/d, speed 30m
The I:1m surface of the aluminum alloy of test II f& was observed with a SEM for 1 hour under the condition of /min to determine the degree of scratches.

Reference Example 1 (Polymerization of PPS resin) Sodium sulfide 3.26 kz (25 mol, including 40% crystal water), thorium hydroxide 4K, sodium acetate trihydrate 1.36 kir (approximately 10 mol) and N were placed in an autoclave. -Methyl-2-pyrrolidone (hereinafter abbreviated as NMP) 7.9 was charged with +r, and while stirring, gradually added 20
The temperature was raised to 5°C, and distilled water containing 1.36 stg of water was produced.
5u was removed. The remaining mixture contained 1,4-dichlorobenzene3, 751qr (25,5 mol) and NMP2.
kg was added and heated at 265°C for 4 hours. The reaction product was washed 5 times with hot water at 70°C and dried under reduced pressure at 80°C for 24 hours to give a melt viscosity of 2,500 voids (320°C, shear distance). i, ooo seconds-1) powdered PP5VtJ resin approximately 2k
I got g.

Repeat the same operation and use it as an example.

Examples 1 to 3 PPS resin powder obtained in Reference Example 1 and aramid fibers such as "Geblar" manufactured by DuPont (diameter 0°3μφ, length 3μ)
and potassium titanate fiber manufactured by Otsuka Chemical Co., Ltd.
Teismo” (diameter 0゜2~0.5μφ, length 10~20
μ) were triblended with the compositions shown in Table 1, and then supplied to a 40 mm diameter single screw extruder set at 290 to 320° C., and melt-kneaded to obtain ppsVA fat composition pellets.

The pellets were supplied to an injection molding machine whose cylinder temperature was set at 280 to 320° C., and the temperature was set to 150° C., to mold a test piece.

Next, the physical properties and sliding properties of the resin composition were measured,
The results are shown in Table 1.

As is clear from Table 1, the PPS resin composition of the present invention has a significantly small wear coefficient and damage to the mating material (aluminum alloy), and has excellent mechanical properties such as strength, and has extremely practical value. It turned out to be a material for high-performance sliding parts.

Examples 4 to 5 Tetrafluoroethylene resin (PTFE) and graphite were further triblended as a lubricant with the composition shown in Table 1, and then tested and evaluated in the same manner as in Example 1.

The results are shown in Table 1, and the composition of this example has a low coefficient of friction, has sliding properties that cause extremely little damage to the mating material, and is a sliding material with excellent mechanical properties. One thing is clear.

Comparative Examples 1 to 4 Aramid fiber alone as reinforcing material (Comparative Example 1), potassium titanate A fiber alone (Comparative Example 2), mixture of potassium titanate fiber and glass fiber (Comparative Example 3), potassium titanate fiber and carbon Melt kneading and injection molding were carried out in exactly the same manner as in Example 1 except that the fiber mixture (Comparative Example 4) was used.
Each physical property was measured. The results are shown in Table 1, and no material was obtained that satisfied both sliding properties and mechanical properties.

<Effects of the Invention> The PPS resin composition of the present invention can significantly reduce wear even when the mating material is a material with low hardness such as an aluminum alloy, and has a low specific gravity and excellent mechanical properties. Therefore, it has extremely great practical value as a sliding material.

Claims (1)

[Claims] (a) Polyphenylene sulfide resin 30-90% by weight
, (b) Composition 100 consisting of 3 to 50% by weight of aramid fibers and (c) 3 to 40% by weight of potassium titanate fibers.
A polyphenylene sulfide resin composition comprising 0 to 40 parts by weight of a lubricant.