JPH07268126A - Lubricating resin composition - Google Patents

Abstract

PURPOSE:To obtain a slidable resin composition capable of using so as not to damage itself and the opposite even under sliding conditions using a soft metal as a pair and capable of sufficiently exhibiting wear resistance and non- aggressive property even under sliding conditions where a lubricating oil does not exist, by packing a carbon fiber CONSTITUTION:This lubricating resin composition is obtained by adding 5-40 pts. vol. of a solid lubricating agent such as polytetrafluoroethylene to 100 pts.wt. of a fiber reinforced resin consisting of 60-95vol.% of a synthetic resin such as polyphenylene sulfide, polyether nitrile, polyether ketone, polyamide, polyimide, polytetra-fluoroethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-perfluoroalkylvinyl ether and tetrafluoroethylene- hexafluoropropylene copolymer and 40-5vol.% of a carbon fiber having ;>=500m<2>/g specific surface area. A sliding bearing and a sliding sealing material are obtained by molding the lubricating resin composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating resin composition applicable to sliding materials such as sliding bearings and sliding sealing materials.

[0002]

2. Description of the Related Art Generally, sliding materials such as plain bearings, which are made of synthetic resin, are required to have required slidability and required mechanical strength, and heat resistance and easy molding. Therefore, it has been necessary to prepare various heat resistant synthetic resins, reinforcing materials and fillers as described below.

As the synthetic resin which is the main component of the sliding material, the heat deflection temperature (ASTM D 648) is 200 ° C.
It is preferable to use a so-called super engineering plastic having heat resistance and mechanical strength that exceeds the above in order to exhibit high function and high durability. Specific examples include polyphenylene sulfide (hereinafter, PPS).
Is abbreviated. ), Polyetherketone (hereinafter abbreviated as PEK), polyimide (hereinafter abbreviated as PI).
Etc.

When added to the main component, the moldability, mechanical strength,
Examples of additives for improving lubricity include glass fibers, carbon fibers, fibrous reinforcing agents such as whiskers, polytetrafluoroethylene (hereinafter abbreviated as PTFE) as a solid lubricant, molybdenum disulfide, and the like. Can be mentioned.

A sliding material formed by mixing such materials is usually used with lubricating oil intervening on the sliding surface. For example, a compressed medium such as a refrigerant gas in a refrigeration cycle is compressed. For sliding seals that prevent the leakage of compressed medium in compressors, or sliding seals for automobile automatic transmissions and brake devices, the sliding surface is fluid lubricated with lubricating oil under normal use. .

[0006]

However, the above-mentioned conventional synthetic resin sliding material may be subjected to boundary lubrication under some conditions during use. Even in such a case, a good sliding state can be obtained. Although the maintenance is important for improving the reliability and safety of the entire device, it cannot be improved yet.

Further, when the sliding mating material is a relatively soft metal such as an aluminum alloy or a stainless steel material, the added fibrous reinforcing material is liable to be worn and damaged, and in extreme cases, abnormal wear occurs. There is also a problem.

When the cause of such abnormal wear is investigated in detail, the tip of the relatively hard fibrous reinforcing material such as glass fiber or carbon fiber attacks the surface of the soft metal, and wear powder generated at that time occurs. Was observed to have a polishing action.

Pitch-based or pan-based carbon fibers are used as a sliding material to which carbon fibers having an excellent filling effect are added as a reinforcing material, and the difference in tensile elastic modulus and other physical properties can be utilized. There are improved techniques such as a technique of limiting the blending ratio within a predetermined range (Japanese Patent Publication No. 63-301258) and a technique of using one with a limited aspect ratio (Japanese Patent Laid-Open No. 2-219895), but filling with carbon fiber having a high reinforcing effect. In the resin composition described above, it was not possible to prevent the soft metal of the sliding partner from being damaged at all.

Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a slidable resin composition filled with a carbon fiber having a high reinforcing effect under sliding conditions against a soft metal such as an aluminum alloy. In addition, both of them can be used without any damage, and can exhibit sufficient wear resistance and non-aggressiveness even under sliding conditions in which no lubricating oil exists.

[0011]

In order to solve the above problems, in the present invention, fiber reinforced consisting of 60 to 95% by volume of synthetic resin and 40 to 5% by volume of carbon fiber having a specific surface area of 500 m ² / g or more. 5 to 40 parts by volume of the solid lubricant was added to 100 parts by volume of the resin to form the lubricating resin composition.

The synthetic resin may be polyphenylene sulfide, polyether nitrile, polyether ketone, polyamide, polyimide, polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and It is possible to employ one or more resins selected from the group consisting of tetrafluoroethylene-hexafluoropropylene copolymer.

The solid lubricant may be one or more solid lubricants selected from the group consisting of polytetrafluoroethylene, molybdenum disulfide and graphite. Then, the above-mentioned lubricating resin composition is molded into a sliding bearing or a sliding seal member.

The details will be described below. The synthetic resin used in the present invention includes a heat deflection temperature (ASTM D 6
It is preferable to use a heat resistant resin whose 48) exceeds 200 ° C., but a general resin material can be selected and used according to the application of the sliding material.

Specific examples of the above-mentioned heat resistant resin include polyphenylene sulfide, (hereinafter abbreviated as PPS) polyether nitrile (hereinafter abbreviated as PEN), and polyether ketone (hereinafter abbreviated as PEK). ), Polyamide (hereinafter abbreviated as PA), polyimide (hereinafter abbreviated as PI), polytetrafluoroethylene (hereinafter abbreviated as PTFE), tetrafluoroethylene-ethylene copolymer (hereinafter ETFE). , A tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (hereinafter abbreviated as PFA) and a tetrafluoroethylene-hexafluoropropylene copolymer (hereinafter abbreviated as FEP),
Polyether sulfone resin, polyether imide resin, polyamide imide resin, I type liquid crystal polymer (hereinafter,
Abbreviated as LCP. ) And the like.

As a typical example of the above PA, 4-
6 Nylon resin (hereinafter abbreviated as PA46) is preferable, and as typical examples of PEK, polyetheretherketone resin (hereinafter abbreviated as PEEK) and polyetherketoneetherketoneketone resin (hereinafter P).
Abbreviated as EKEKK. ) Is mentioned.

The following are some of the particularly marketed and preferred ones. PPS (Tosoh Steel Co., Ltd .: # 160, Topren Co., Ltd .: T4AG) PEN (Idemitsu Material Co., Ltd .: ID300) PEEK (ICI Co., Ltd .: Victorex PEEK) PEK (ICI Co., Ltd .: Victorex PEK) PEKEKK (BASF Co., Ltd.) Made: Ultra PEK) PI (Mitsui Toatsu Chemicals Inc .: Aurum) PA46 (Nippon Synthetic Rubber Co., Ltd .: KS300) LCP (Sumitomo Chemical Co., Ltd .: Sumika Super, Nippon Oil Co., Ltd .: Zaider) PTFE (Daikin Industries Co., Ltd .: M-15, Asahi Glass Co., Ltd .: G163, Mitsui DuPont Fluorochemical Co., Ltd .: 7
J) ETFE (manufactured by Asahi Glass Co., Ltd .: Aflon COP) PFA (manufactured by Asahi Glass Co., Ltd .: Aflon PFA) Next, the carbon fiber having a specific surface area of 500 m ² / g or more used in the present invention is a pitch-based or pan-based carbon fiber. Carbonized products that have been fired at about 1000 ° C (specific surface area 1 m ² /
g) is surface-treated with an oxidant in an inert gas atmosphere, and the surface is activated (made porous) like so-called activated carbon. When the specific surface area of the activated carbon fiber is less than 500 m ² / g, the resin composition containing the carbon fiber tends to attack the soft metal in a sliding state, which is not preferable. The specific surface area can be increased up to about 2000 m ² / g by adjusting the processing conditions such as the surface treatment time, but if it is too large, the mechanical strength such as elastic modulus decreases, and the original carbon fiber The composition does not have a reinforcing effect such as abrasion resistance. Considering such a tendency, a more preferable specific surface area is 700 to 1500 m ² /
It is g.

The fiber diameter of the carbon fiber having a predetermined specific surface area is preferably 20 μm or less, more preferably 10 to 15 μm, in which case the aspect ratio is preferably 5 to 80, More preferably 2
0 to 50. The reason is that if the aspect ratio is less than 5, it is difficult to improve the mechanical strength of the composition with good addition efficiency, and the reinforcing effect increases as the aspect ratio increases, but even if it exceeds 80, the composition is mechanical This is because the mechanical strength is not improved so much from the viewpoint of practicality.

As the solid lubricant used in the present invention, known solid lubricants can be used without limitation as long as they give the composition a desired sliding property.

Specific examples of such a solid lubricant include:
Examples thereof include PTFE, silicone resin, graphite, molybdenum disulfide and the like. Of these, PTFE is particularly preferable because it improves lubricity with good addition efficiency, and either a molding powder by a suspension polymerization method or a fine powder by an emulsion polymerization method may be used, but it is subjected to pressure / heat treatment. Then, the powdery PTFE having an average particle size of 10 μm or less after being pulverized and irradiated with γ-ray is preferable.

The mixing ratio of the raw materials of the composition of the present invention is
Synthetic resin 60-95% by volume, specific surface area 500 m ² / g
The solid lubricant is 5 to 40 parts by volume with respect to 100 parts by volume of the fiber-reinforced resin containing 40 to 5% by volume of the carbon fibers.

If the content of carbon fiber exceeds 40% by volume, the injection molding of the composition becomes difficult, and if it is less than 5% by volume, the reinforcement of the composition becomes insufficient and the abrasion resistance cannot be sufficiently obtained. Further, if the solid lubricant exceeds 40 parts by volume, injection molding becomes difficult and the wear resistance cannot be maintained at a required level. Also, if it is less than 5 parts by volume, the effect of imparting lubricity is poor and sufficient sliding characteristics cannot be obtained, which is not preferable.

Known additives as listed below may be added as long as the effects of the present invention are not impaired.

(1) Abrasion enhancer: boron fiber, aramid fiber, etc. (2) Conductivity improver: carbon, zinc oxide, titanium oxide, etc. (3) Cracking improver: graphite, mica,
Talc, wollastonite, etc. (4) Thermal conductivity improver: powdered metal oxide (5) Toughness improver: silicone resin, polyolefin resin, etc. The raw materials used in the present invention described above are mixed and kneaded. , To obtain a lubricating resin composition by molding, but the means for mixing and kneading is not particularly limited, and only powder raw materials are dry-mixed using a Henschel mixer, a ball mixer, a ribbon blender, an Ultra Henschel mixer, or the like. In addition, if it is a thermoplastic resin that can be injection molded,
Melt blending can be carried out with a biaxial melt mixer to obtain molding pellets (granules). As the molding method, an appropriate molding method may be appropriately adopted for the resin to be the matrix, for example, pressure compression molding, sintering molding, injection molding,
Hot homing molding or the like can be adopted.

[0025]

The lubricating resin composition of the present invention has lubricity due to the solid lubricant, the surface of the added carbon fiber is activated and has a predetermined specific surface area, and a lubricating oil is present. Under dynamic conditions, the lubricating oil can be adsorbed to the pores (micropores) and stable fluid lubrication can be performed.
It will keep the friction coefficient stable and at a low level.

Further, when the carbon fiber is destroyed by the shearing force during friction, only the load portion is partially collapsed, and the cut surface is gradually collapsed and rounded. It is considered difficult to do.

Further, the specific surface area of the carbon fiber is set within a predetermined range, and the composition itself containing the carbon fiber in a predetermined ratio has improved abrasion resistance and mechanical strength to a required degree.

[0028]

EXAMPLES The raw materials used in Examples and Comparative Examples are collectively shown below. In the table below, these abbreviations are shown in parentheses, and the mixing ratio is defined as 10% by volume of the mixing ratio of synthetic resin and carbon fiber.
The blending ratio of the solid lubricant is indicated as 0 part by volume.

(1) Polyphenylene sulfide resin [PPS] made by Topren: T4AG (2) Polyether nitrile resin [PEN] made by Idemitsu Material: ID300 (3) Polyether ether ketone resin [PEEK] made by ICI: Victorex PEEK (4) Polyimide resin [PI] Mitsui Toatsu Chemicals Inc .: Aurum 450 (5) Polyamide 4-6 resin [PA46] Nippon Synthetic Rubber Co., Ltd .: KS300 (6) Tetrafluoroethylene-ethylene copolymer [E
TFE] Asahi Glass Co., Ltd .: Aflon COP (7) Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer [PFA] Asahi Glass Co., Ltd .: Aflon PFA (8) Tetrafluoroethylene [PTFE] Asahi Glass Co., Ltd .: G163 (9) carbon fiber (Specific surface area 700 m ² / g) [CF-A
7] Osaka Gas Chemical Co., Ltd .: Fibrous activated carbon ADOL-A7 (10) Carbon fiber (specific surface area 1000 m ² / g) [CF
-A10] Osaka Gas Chemicals Co., Ltd .: Fibrous activated carbon ADOL-A10 (11) Carbon fiber (specific surface area 2000 m ² / g) [CF
-A20] Osaka Gas Chemical Co., Ltd .: Fibrous activated carbon ADOL-A20 (12) Carbon fiber (specific surface area of about 1 m ² / g) [CF] Kureha Chemical Co., Ltd .: M107T, carbonized product (13) Carbon fiber (specific surface area) About 1 m ² / g) [CF] Kureha Chemical Co., Ltd .: M207S, graphitized product (14) Polytetrafluoroethylene [PTFE] Kitamura Co., Ltd .: KTL610 (15) Graphite Nippon Graphite Co., Ltd .: ACP (16) Aramid Fiber Japan Aramid: Twaron, 0.25 mm (17) Activated carbon powder (specific surface area of about 2000 m ² / g) Average particle size 5 to 10 μm [Examples 1 to 14 and 16] Raw materials in a Henschel dry type at a compounding ratio shown in Table 1. Dry blend using a mixer,
Kneading was performed using a biaxial melt mixer to prepare granulated pellets. This pellet is φ15 × φ25 × 2 by injection molding machine
Φ17 × φ formed by cutting 0 (mm) blanks
A 21 × 10 (mm) ring-shaped test piece was obtained.

Using this test piece, the coefficient of dynamic friction, the amount of wear, and the degree of damage to the mating material under lubricating oil or unlubricated conditions were investigated, and the results are shown in Table 2.

A thrust type friction and wear tester was used as the tester, and the test conditions in the lubricating oil were aluminum die cast of the mating material (ADC12), peripheral speed of 60 m / min, load of 2
5 kgf / cm ² when immersed in suniso oil
The test was performed for 0 hours. The test conditions under non-lubricating conditions are aluminum die cast (ADC12) of the mating material,
The test was carried out at a peripheral speed of 60 m / min and a load of 2 kgf / cm ² for 50 hours. The degree of damage to the mating material was evaluated with the naked eye in three grades: ○ (no damage), Δ (slightly damaged), and × (damaged).

[0032]

[Table 1]

[0033]

[Table 2]

Example 15 The raw materials were dry blended in the blending ratios shown in Table 1 using a Henschel dry mixer, and φ was applied using a press at a pressure of 500 kgf / cm ^2.
Mold a 30 x 100 (mm) base material, 380 ℃, 5
Φ17 × φ21 × 10 by free-time heating and cutting
A ring-shaped test piece of (mm) was obtained.

Using this test piece, the dynamic friction coefficient, the amount of wear, and the degree of damage to the mating material under lubricating oil or no lubrication conditions were examined in exactly the same manner as in Example 1, and the results are also shown in Table 2.

[Comparative Examples 1 to 12 and 14] Ring-shaped test pieces were prepared in the same manner as in Example 1 except that the raw materials were mixed in the proportions shown in Table 3, and the test pieces were used in Examples. The dynamic friction coefficient, the amount of wear, and the degree of damage to the mating member under the condition of lubricating oil or no lubrication were examined in exactly the same manner as in No. 1, and the results are shown in Table 4.

[Comparative Example 13] A ring-shaped test piece was prepared in exactly the same manner as in Example 15 except that the raw materials were mixed in the proportions shown in Table 3, and this test piece was used in exactly the same manner as in Example 1. The coefficient of kinetic friction, the amount of wear, and the degree of damage to the mating material under the condition of lubricating oil or unlubricated oil were investigated,
It was shown to.

[0038]

[Table 3]

[0039]

[Table 4]

As is clear from the results shown in Tables 2 and 4, in Comparative Examples 1 to 3 in which the predetermined materials were used but the compounding ratios thereof were unsuitable, molding could not be performed or wear resistance was poor. It was the result.

In Comparative Examples 4 to 7 in which the predetermined carbon fiber or solid lubricant or both of them were not blended, one or more of the dynamic friction coefficient, the wear amount and the degree of damage of the mating material had a defect. .

In Comparative Examples 8 to 13, the mating material may not be attacked under the test conditions in the lubricating oil, but all the mating materials were attacked under the unlubricated condition. Also, the specific surface area is 500
Although it was m ² / g, Comparative Example 14 containing activated carbon which was not carbon fiber had a poor reinforcing effect on wear resistance.

On the other hand, the examples satisfying all the conditions were excellent in all of the dynamic friction coefficient, the amount of wear, and the degree of damage of the mating material not only under the test conditions in the lubricating oil but also under the unlubricated test conditions. .

Therefore, such a lubricating resin composition can be used in the vicinity of the engine of office equipment such as electronic copying machines, radial bearings for heat fixing parts of printers, heat insulating sleeves, automobiles, motorcycles, and heavy machinery for construction. It can be applied to bearings or wet friction materials. Further, it can be said that it can be applied as a sliding seal material for sealing refrigerant gas, oil, and air.

[0045]

As described above, according to the present invention, a solid lubricant and a carbon resin having a predetermined specific surface area whose surface is activated are added in predetermined amounts, respectively. It can be used so that neither oneself nor others will be damaged even under the sliding condition against the soft metal mentioned above, and it can exhibit sufficient wear resistance and non-aggressiveness even under the sliding condition in which no lubricating oil exists. There are advantages.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08L 33/18 LJK 71/10 LQJ LQK 77/00 KLC 79/08 LRB 81/02 LRG 101/00

Claims (5)

[Claims] 1. A solid lubricant 5-4 with respect to 100 parts by volume of a fiber-reinforced resin consisting of 60-95% by volume of synthetic resin and 40-5% by volume of carbon fiber having a specific surface area of 500 m ² / g or more.
A lubricating resin composition obtained by adding 0 parts by volume. 2. The synthetic resin is polyphenylene sulfide, polyether nitrile, polyether ketone, polyamide, polyimide, polytetrafluoroethylene,
The lubricity according to claim 1, which is one or more resins selected from the group consisting of a tetrafluoroethylene-ethylene copolymer, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer and a tetrafluoroethylene-hexafluoropropylene copolymer. Resin composition. 3. The lubricating resin composition according to claim 1, wherein the solid lubricant is one or more solid lubricants selected from the group consisting of polytetrafluoroethylene, molybdenum disulfide and graphite. 4. A plain bearing formed by molding the lubricating resin composition according to claim 1, 2, or 3. 5. A sliding seal material obtained by molding the lubricating resin composition according to claim 1, 2, 3, or 4.