JPH01242662A - Sliding resin composition - Google Patents

Abstract

PURPOSE:To provide a sliding resin composition suitable as a material for a sliding part which can withstand high-temperature and high-load conditions, by adding a specified amount of a carbon fiber and a carbon powder of a controlled particle diameter to an aromatic polyetherketone resin. CONSTITUTION:60-5wt.% carbon fiber (B) and 30-5wt.% carbon powder (C) of a mean particle diameter of 1-200mum (e.g., natural graphite powder or carbon black) are added to 10-90wt.% aromatic polyether ketone resin (A) containing repeating units of formula I and, optionally, repeating units of formulas II, III, IV or the like, and the obtained mixture is mixed with a Henschel mixer or the like and pelletized with a melt extruder or the like to produce a sliding resin composition. A molding of the obtained resin composition is small in anisotropy, excellent in heat resistance, sliding property, mechanical properties, etc., and can be suitably used as a material for sliding parts suck as pistons, and bearings.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a sliding resin composition for sliding member materials that are exposed to high temperatures and high loads.

[Conventional technology]

Conventionally, polyetherketone resins have attracted attention as engineering plastics with excellent heat resistance, flame retardance, chemical resistance, etc., particularly in the fields of electrical and electronic equipment and vehicle equipment such as automobiles. However, this resin is used for general industrial use where mechanical properties such as strength, rigidity, and friction and wear resistance are strongly required. In the field of appliances, this is not satisfactory, and improvements in strength and rigidity using fibrous reinforcing agents such as glass fiber have been proposed for such resins.
Various attempts have been made to improve wear resistance using solid lubricant powders such as tetrafluoroethylene resin and molybdenum disulfide. In order to ensure sufficient abrasion resistance under such an atmosphere, it is necessary to add a considerably large amount, and the balance of mechanical properties that the resin composition should have cannot be maintained. Further, when a fibrous reinforcing agent is added alone, anisotropy and warpage occur due to the orientation of the fibrous reinforcing agent, and in addition, sufficient sliding properties cannot be obtained.

[Problem to be solved by the invention]

In this way, in conventional technology, in addition to excellent heat resistance, chemical resistance, abrasion resistance, etc., the thermal expansion coefficient is small, anisotropy is extremely low, mechanical strength is high, and load resistance is excellent. Moreover, there was a problem that it was impossible to obtain a sliding resin composition that could be used at high temperatures and high loads and had structural material elements such as being able to be injection molded, and it was a challenge to solve this problem. .

[Failure to solve the problem]

In order to solve the above problems, this invention combines 10 to 90% by weight of aromatic polyetherketone resin with 5 to 90% carbon fiber.
This method employs a method of forming a sliding resin composition to which 60% by weight and 5 to 30% by weight of carbon powder having an average particle size of 1 to 200 mm is added, and the details thereof will be described below.

First, the aromatic polyetherketone used in this invention contains repeating units alone or together with other repeating units, and has an intrinsic viscosity of 0.7 to 2.6, preferably 0.8 to 168. belongs to. Here, other repeating units may be contained in an amount of less than 25% by weight, but a polymer containing more than 25% by weight is not preferred because the original properties of polyetherketone are lost. In addition, the intrinsic viscosity is the intrinsic viscosity measured for a polymer solution in concentrated sulfuric acid with a density of 1.84 g/cIIl containing 0.1 g of polymer per 100 cffl of the solution, and the measurement takes about 2 minutes for the solvent to flow out. I used a meter. This intrinsic viscosity is a value that uniquely corresponds to the molecular weight of the polymer, and polyetherketones with an intrinsic viscosity lower than 0.7 have low heat resistance and are extremely brittle even if molded products are obtained;
If the melt viscosity exceeds this value, the melt viscosity is too high, resulting in poor processability and cannot be used generally.

Further, the carbon IHt that can be used in the present invention may be any one of acrylonitrile type, pinch type, cellulose type, etc., and preferably has a fiber length of 0101 to 10 mo+, so 61I1m or 31% of fiber length is preferably used as a resin filler. Chirambued fibers, rovings, etc. of a certain length can be used. It is preferable to use carbon fibers whose surfaces have been treated with a treatment agent such as epoxy resin, polyamide resin, polycarbonate resin, or polyacetal resin, but are not limited thereto.

Examples of such carbon fibers include Vercules Co., Ltd.'s Magnamite to S1 Magnamite 1 (Mon), Toshi Co., Ltd.'s Trading Card T300A, and Toho Rayon Co., Ltd.'s Besphi!-HTA.
, Hesphi order 0OO1 Kureha Chemical Industry Co., Ltd.! ! ! : Examples include Credit Card M and Credit Card C.

Further, the carbon powder used in the present invention is not limited to one with a perfect graphite structure, but can also be an imperfect amorphous carbon powder. In the case of graphite, any of natural graphite, artificial graphite, quiche graphite, etc. may be used, and any type of graphite known as natural graphite, such as flaky, lumpy, granular, acicular, or beaded, can be used. In the case of amorphous carbon, any of coke, gas carbon, anthracite, carbon blank, lamp blank, animal charcoal, charcoal, and other carbon-like substances can be used. And these particle sizes have an average particle size of 1 to 200p, especially 2 to 10p.
The shape is preferably 0, but the shape is not particularly limited, such as spherical, acicular, flaky, hollow spherical, etc. Here, the reason why the average particle size is limited as described above is that even fine particles below IQ or large particles exceeding 200 tns are undesirable because they reduce the mechanical strength of the composition to which they are added. It is from. Examples of carbon powders that can be used in this invention include ACP manufactured by Nippon Graphite Co., Ltd., G117 manufactured by Tokai Carbon Co., Ltd., G117 manufactured by Kureha Chemical Industry Co., Ltd., and Tarekas Fair A-50 manufactured by Kureha Chemical Industry Co., Ltd. Manufactured by: mesocarbon microbeads, etc.

When blending the above aromatic polyetherketone resin, carbon fiber, and carbon powder with an average particle size of 1 to 200 μm, the aromatic polyetherketone resin should be added in an amount of 10 to 90% by weight.
It is desirable that the carbon fiber content be 5 to 60% by weight, and the carbon powder with an average particle size of 1 to 200 μm be 5 to 30% by weight. This is because the total amount of carbon fiber and carbon powder is 90% of the resin composition.
If the content of the aromatic polyether carbon resin exceeds 10% by weight, the resin itself will lose its fluidity, and even if a molded product is obtained by injection molding, its mechanical strength will be very low. If the carbon fiber and carbon powder filling amounts are both less than 5% by weight, the reinforcing effect will not appear and the effect of improving anisotropy such as thermal expansion coefficient and molding shrinkage rate will not be sufficient. be.

Various operations such as blending, heating, melting, and mixing of these layer materials are carried out using heated rollers, Banbury mixers, blinders, extruders, etc.
The process may be continued until a homogeneous mixture is obtained at 0 to 380"C, but after pre-mixing the various layer materials in a mortar, Henschel mixer, ball mill, ribbon blender, etc. 30 using a molding machine etc.
It may be appropriately formed into pellets, wires, rods, plates, sheets, and other arbitrary shapes at a temperature of 0 to 400°C, preferably 320 to 380°C.

In the resin composition of the present invention, solid lubricants such as silica powder, molybdenum disulfide, and fluororesin, J Reinforcing materials such as lath fibers, boron fibers, silicon carbide fibers, asbestos, rock wool, and metal fibers, flame retardants such as antimony dioxide, magnesium carbonate, and calcium carbonate, electrical property improvers such as clay, mica, asbestos, and silica, and sulfuric acid. Acid resistance improvers such as barium, silica, calcium metasilicate, fillers such as glass peas, glass bulbs, calcium carbonate, alumina, talc, diatomaceous earth, hydrated alumina, shirasu balloons, and other metal oxides, and pigments. A substance that is stable at high temperatures of about 350° C. or higher may be mixed as appropriate.

〔Example〕

The raw materials used in the Examples and Comparative Examples are listed below. That is, ■ Aromatic polyetherketone resin (manufactured by ICI, UK: Udel-P)
EEK 150P) (abbreviated as PEEK), ■Carbon fiber (Kureka M2O7S, manufactured by Kureha Chemical Co., Ltd.), ■
Same as above (manufactured by Toshisha: Trading card T3008), ■ Carbon powder
(manufactured by Nippon Graphite Industries Co., Ltd.: ACP), Examples 1 to 5: The above raw materials were blended in the proportions shown in Table 1, thoroughly mixed using a Henschel mixer, and then mixed using a twin-screw melt extruder (
Ikegai Tekko Co., Ltd.: PCM-30 type) with a diameter of approximately 2.
Granulated into 5+m pellets. The obtained pellets were put into an injection molding machine with a barrel temperature of 310 to 380° C., a mold temperature of 200° C., and an injection pressure of 1500 kg/cd to prepare a predetermined test piece. And as for mechanical properties, ASTM-
Bending strength (kg/cfll) based on 0790, ^S
The heat distortion temperature ('C) and sliding properties based on TM-0648 (load 18.6 kg/c-d) were measured using a Nilast type friction/wear tester manufactured by Yobea Rulon Industries Co., Ltd. and a wear ring specimen of the same size. Used, PV 2000kg/
cd-1* The wear coefficient was determined under the conditions of 7 minutes, mating material FC-25, and Suniso 4GS oil atmosphere. In addition, a prismatic test piece (length 2m+, width 2m, length 10m+
) as a sample, and measured the expansion amount of the sample from room temperature to 150°C when the heating rate was 5°C per minute using a thermomechanical analyzer TM-30 (manufactured by Shimadzu). The linear expansion coefficients in the flow direction and in the direction perpendicular to the flow direction were determined using the following method. The measured values obtained are summarized in Table 1.

Comparative Examples 1 to 5 in Table 1: Test specimens were prepared in exactly the same manner as in Example 1 □ 5, except that the layered materials ■ to ■ were blended in the proportions shown in Table 2. Strength, wear coefficient, thermal distortion temperature and linear expansion coefficient were measured. The results obtained are summarized in Table 2.

Here, when comparing Examples 1 to 5 and Comparative Examples 1 to 5 from Tables 1 and 2, it can be seen that the blending ratios of Examples 1 to 5 are all within the desired range of the present invention, so the mechanical properties It has excellent thermal properties and lubricating properties. However, in Comparative Examples 1 to 5, even one of the blending ratios of aromatic polyether ketone, carbon fiber, and carbon powder deviated from the desirable range of the present invention, resulting in poor characteristics as described in the examples. It is impossible to satisfy all. That is, when the amount of carbon fiber is less than 5% as in Comparative Example 1, and when the amount of aromatic polyetherketone resin is more than 90% as in Comparative Example 3, the linear expansion coefficient is large and the mechanical When the strength is low and the wear coefficient is high, or when the amount of carbon powder is less than 5% as in Comparative Example 2,
It has high mechanical strength but a large coefficient of linear expansion.

Table 2 Also, when the amount of carbon fiber exceeds 60% as in Comparative Example 4, the mechanical strength is low, the abrasion coefficient is large, and anisotropy occurs in the linear expansion coefficient. Furthermore, when the amount of carbon powder exceeds 30% as in Comparative Example 5, the mechanical strength is low.

[Effects] As described above, the sliding resin composition of the present invention is suitable as a material for sliding parts that can withstand high temperatures and high loads, and molded products obtained by injection molding or compression molding have anisotropic properties. It has extremely low thermal properties (heat resistance), mechanical properties, and sliding properties. Therefore, this material is suitable as a material for sliding parts that have excellent mechanical properties such as pistons, piston rings, bearings, combination parts, thrust washers, rotating body insulation sleeves, and printer parts. It can be said that the significance of the invention is extremely large.

Claims (1)

[Claims] (1) Aromatic polyetherketone resin 10-90% by weight
5-60% by weight of carbon fiber, average particle size 1-200μ
A sliding resin composition characterized in that 5 to 30% by weight of carbon powder of m is added.