JPH02219895A - Composition for sliding member material - Google Patents

Abstract

PURPOSE:To obtain the title compsn. capable of decreasing remarkably frictions of itself and a mating material and having excellent sliding characteristics under a high PV condition especially to a soft mating materials by mixing each a specified amt. of each a specified carbon fiber, Ca compd. powder and tetrafluoroethylene resin. CONSTITUTION:The title compsn. comprises 2-30wt.% carbon fiber with a mean fiber diameter of 1-20mu and an aspect ratio of 1-50, 0.5-50wt.% Ca compd. (e.g. CaCO3) powder as the essential ingredients and the balance of a tetrafluoroethylene resin.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a composition for a sliding part material essential for mechanical elements.

[Conventional technology] Tetrafluoroethylene resin has excellent heat resistance, chemical resistance, and sliding properties, so it is widely used as a sealing material1. However, when using this resin alone, the amount of deformation due to external force is large. Also, since the amount of wear is large, attempts have been made to improve these drawbacks by adding various fillers. For example, glass fiber, carbon fiber, metal powder, etc. are used as fillers, but in recent years there has been an increase in consideration of their use under harsh conditions, and conventional fillers have limited PV values (here, P
The V value is used to express bearing characteristics and serves as a guideline for mutual comparison of bearing materials.It is expressed as a function of pressure P and sliding surface speed V, and the higher this value, the better the pressure resistance and durability. However, due to the low speed (which means that it has excellent speed), it has become impossible to meet such demands. In addition, aluminum is increasingly being used as a mating material for sliding parts due to the recent trend toward weight reduction, but conventional materials for sliding parts wear out the mating aluminum material, so it is difficult to use when using it. There were many difficulties.

[Problem to be solved by the invention]

In this way, conventional technology has been able to create a slide that has a high limit PV value, hardly wears out soft mating materials such as aluminum, and can withstand the usage conditions that have become particularly severe in recent years. There is a problem in that a composition for a sliding part material having dynamic properties has not been obtained, and it has been an issue to solve this problem.

[Means for Solving the Problems] In order to solve the above problem 11B, the present invention uses 112 to 30% by weight of carbon having an average fiber diameter of 1 to 20 and an aspect ratio of 1 to 50, and an average particle diameter of 112 to 30% by weight. is 0.5~40JI
- 035 to 50% by weight of calcium compound powder as an essential component, and the remainder is tetrafluoroethylene resin. The details will be described below.

First, the tetrafluoroethylene resin (hereinafter P
(abbreviated as TFE) is a homopolymer of tetrafluoroethylene, manufactured by Montegisson in Italy: Hyflon, manufactured by DuPont in the United States: Teflon, and manufactured by ICI&! in the United Kingdom. =
It is a type of fluororesin that is commercially available under the respective registered trademark names such as Fluon and Polyflon (manufactured by Daikin Industries, Ltd.), and although it is compression moldable, ordinary injection molding is not possible.

Next, the carbon fiber in this invention has an average fiber diameter of 1
~20/III, preferably 5 to 15 μm, and an aspect ratio of 1 to 50, preferably 5 to 30. This is because if the average fiber diameter is less than 1μ, the fibers will aggregate, making uniform dispersion difficult, and
If the aspect ratio exceeds 0, it will wear out the soft mating material, if the aspect ratio is less than 1, the reinforcing effect of the matrix itself will be impaired and the mechanical properties will deteriorate, and if it exceeds 50, the uniform dispersion during mixing will deteriorate. This is because it is extremely difficult and undesirable as it impedes the wear characteristics and leads to quality deterioration.

And, such desirable carbon fibers are manufactured by Toshisha:
Trading car LD-30, manufactured by Kureha Chemical Industry Co., Ltd.: Credit card M2O
Examples include 1S and M2O07S.

Furthermore, the calcium compound in this invention is a carbonate, sulfate, oxide, or hydroxide of calcium, and calcium carbonate and calcium sulfate are particularly preferred.
The reason why the average particle size of these calcium compounds is limited to a range of 0.5 to 40 μm, preferably 1 to 30 μm is that 0.5
This is because if the particle size is less than itm, agglomeration between particles will occur, making uniform dispersion difficult, and if the particle size is larger than 40u+, the surface smoothness will deteriorate, which is undesirable.

The blending ratio of these essential components in this invention is 112% to 1% carbon fiber, preferably 5% to 20% carbon fiber.
, calcium compound 0.5-50% by weight, preferably 2
~35% by weight, with the remainder being tetrafluoroethylene resin.The reason is that if the amount of carbon fiber is less than the lower limit, little improvement in wear resistance can be expected, and if the amount exceeds the upper limit, Calcium compounds start to wear out the soft mating material, and when the calcium compound is in a small amount below the lower limit above, it also wears out the soft mating material, and on the other hand, when the calcium compound is in a large amount exceeding the upper limit, it causes a decrease in mechanical properties, which is undesirable. It is from.

The mixture blended in the above proportions can be molded under the usual molding conditions for PTFEI with fillers that have been widely used in the past (for example, PTF [!, carbon fiber , the three components of the calcium compound are dry mixed, put into a mold and preformed by applying a pressure of 380 to 600 kg/i, and then the compression molded body taken out from the mold is
℃ sintering, batch compression molding while heating and pressurizing oil, or continuous extrusion using a ram extruder. In addition, in the resin composition of the present invention, As in the case of ordinary resin compositions, within a range that does not impede the main purpose of this invention,
For example, solid lubricants such as carbon powder, silica powder, and molybdenum disulfide; reinforcing agents such as glass fiber, boron fiber, silicon carbide fiber, asbestos, rock wool, and metal fiber; flame retardants such as antimony dioxide and magnesium carbonate; , mica,
Electrical property improvers such as asbestos, silica, and graphite, acid resistance improvers such as barium sulfate and silica, glass beads,
Glass bulbs, alumina, talc, diatomaceous earth, hydrated alumina, shirasu balloons, fillers such as other metal oxides, and even pigments, all of which are stable at high temperatures of about 380°C or higher, are appropriately mixed. Good too.

When such additives are added, the blending ratio of the remaining fluorinated ethylene resin is preferably not less than 151° C. mass %.

〔Example〕

The raw materials used in the Examples and Comparative Examples described below are listed below. In addition, the respective abbreviations are written in brackets [ ], and the blending ratio is in weight %.

■Tetrafluoroethylene resin (PTFII) (manufactured by Null DuPont Fluorochemical Co., Ltd.: Teflon 7J.

powder), ■Carbon fiber (CF-1) (manufactured by Toshisha: Torayka MLD30, average ta fiber diameter 7 μm,
Aspect ratio 1 to 30), ■Carbon fiber [CF-2] (manufactured by Kureha Chemical Industry Co., Ltd.; Kureki-2013, average 1m diameter 1
2.5 JI Peng, aspect ratio 1-40), ■ Calcium carbonate (CaC05) (manufactured by Nichiryo Kogyo Co., Ltd. = N^600, average particle size 7 μm), ■
Calcium sulfate (CaOs) (manufactured by Wako Pure Chemical Industries, Ltd.: reagent grade, average particle size Iμ-), Examples 1 to 5: Each raw material was dry blended in the proportions shown in Table 1, and this was put into a mold. After preforming under a pressure of 550 kg/c-,
The compression molded body taken out from the mold was sintered at 370° C., and test pieces having dimensions and shapes specified in various test methods were produced from this molded body. The various test methods are as follows.

(]) Tensile strength (kg/ej) and elongation (%) AS
Based on Tl'l-0638, (2) Linear expansion coefficient (XIO-'/'C)^5T)1-D
695, (3) Friction test Sliding speed by thrust type friction tester 150 m/min, 1
Find the friction coefficient under forced lubrication conditions, weight 1.1 kg/cj, mating material 〇 (knee 12 (T6 treatment), lubricant Suniso 4GS).

(4) Wear coefficient (xlO-”cj/kg-m) Low P
The V conditions were a sliding speed of 96 m/min using a thrust type abrasion tester, a load of 5 kg/cd, and a mating material ^0C12.
('r6 processing), select the forced lubrication conditions of lubricating oil Suniso 4GS and find its wear coefficient. In addition, as a high PV condition,
A sliding speed of 128 m/min using a thrust type abrasion tester, a load of tokg/e+J, and the other conditions are the same as those for the low PV condition described above, and the wear coefficient at that time is determined.

The results obtained from each of the above tests are also listed in Table 1.

Comparative Examples 1 to 4; Test pieces were prepared in exactly the same manner as Examples 1 to 5, except that the proportions of each raw material were as shown in Table 2, and various tests were conducted. The obtained results are also listed in Table 2.

Table 1, Section 2'a The following is clear from Tables 1 and 2. In other words, the molded bodies obtained in Examples 1 to 5 comprising the composition for sliding article materials of the present invention all exhibited balanced mechanical properties, and exhibited a high resistance to heart motion under high PV conditions relative to the soft mating material. The properties are also very good, and the balance on both sides is very good. On the other hand, in Comparative Example 2, in which the amount of carbon fiber added was outside the limited range of the present invention, the wear coefficient was large especially under high PV conditions, and in Comparative Example 4, the wear of the mating material was large and the friction The coefficient was also high, and furthermore, the tensile elongation, which is one of the mechanical properties, was significantly reduced. In addition, the molded body in Comparative Example 1, in which the amount of calcium compound added was outside the limited range of the present invention, had a large amount of wear on the mating material, and the molded body in Comparative Example 3 also had large wear, especially under high PV conditions (friction coefficient Furthermore, the tensile elongation, which is one of the mechanical properties, was also significantly decreased.
It was considerably inferior to any of the above, and was not desirable.

〔effect〕

The composition for sliding article materials of the present invention, which is obtained by blending carbon fibers and calcium compounds with tetrafluoroethylene resin, has a higher self- and Abrasion of the mating material can be significantly reduced, and the sliding properties are particularly excellent against soft mating materials under high PV conditions.For example, sliding parts such as seal rings for compressors under high PV conditions of aluminum mating materials. It can be a very advantageous material for manufacturing.

Patent applicant: Western Bear Rulon Industrial Co., Ltd. Agent: Aya Kamata

Claims (1)

[Claims] (1) 2 to 30% by weight of carbon fibers with an average fiber diameter of 1 to 20 μm and an aspect ratio of 1 to 50, and 0.5 to 30% of calcium compound powder with an average particle diameter of 0.5 to 40 μm.
50% by weight as an essential component, and the remainder being tetrafluoroethylene resin.