JPH06212080A - Lubricating resin composition - Google Patents

Abstract

PURPOSE:To obtain a lubricating resin composition exhibiting excellent lubricating characteristics without damaging the counter material even in the case of using a soft material such as aluminum alloy as the counter material slidably contacting with the composition. CONSTITUTION:This lubricating resin composition is produced by compounding a thermoplastic resin such as polyphenylene sulfide resin with 5-35vol.% of powdery fluororesin for molding or fluororesin fine powder for solid lubricant (e.g. polytetrafluoroethylene resin) and 3-35vol.% of powdery tin oxide having particle diameter of 0.1-100mum such as stannous oxide (SnO) or stannic oxide (SnO2) as essential components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating composition used as a material for various sliding parts.

[0002]

2. Description of the Related Art In recent years, in response to the demand for weight reduction of mechanical products, techniques for replacing conventional metal machine parts with synthetic resin parts are being developed in various fields, and sliding parts such as bearings are also being developed. Technologies corresponding to this have been developed.

When imparting lubricity to a thermoplastic synthetic resin, a composite material to which a lubricant or the like is added must be added. As the lubricant used in that case, for example, graphite, tetrafluoroethylene resin, lubricating oil, silicate,
There are aromatic polyamide resins and the like.

In addition, an inexpensive aluminum alloy A5056 or the like is often used as a mating member that is slidably held on the bearing.

[0005]

However, the above-mentioned conventional lubricating composition which is a material for bearings is not sufficient in that it exhibits good friction and wear characteristics under high load conditions. In particular, a composite material in which a tetrafluoroethylene resin and a heat-resistant synthetic resin powder are added to a thermoplastic resin damages the sliding partner material of an aluminum alloy of a soft metal, and damages it, causing friction. -There is a problem that wear characteristics deteriorate rapidly.

Therefore, the present invention solves the above-mentioned problems and provides a good lubricating property without damaging the lubricating composition even when the sliding material is a soft material such as an aluminum alloy. The challenge is to bring out the characteristics.

[0007]

In order to solve the above-mentioned problems, the present invention uses a thermoplastic resin, a fluororesin 5 to 3
This is because a structure in which 5% by volume and 3 to 35% by volume of tin oxide are added is adopted.

The details will be described below. First, the thermoplastic resin in the present invention is not particularly limited, and the following resins can be adopted.

That is, vinyl chloride resin, vinyl chloride
Resin, polyethylene (low density, high density or ultra polymer
Quantity), chlorinated polyolefin, polypropylene,
Modified polyolefin, water-crosslinked polyolefin, ethylene
-Vinyl acetate copolymer, ethylene-ethyl acrylate
Rate copolymer, polystyrene, ABS resin, polyamid
De, methacrylic resin, polyacetal, polycarbonate
G, cellulose resin, polyvinyl alcohol, polyuret
Tan elastomer, thermoplastic polyimide, polyether
Imide, polyamide imide, ionomer resin, polyf
Enylene oxide, methyl pentene polymer, polyene
Ryl sulfone, polyallyl ether, polyether A
Terketone, polyphenylene sulfide, polysulfone
Polyester, wholly aromatic polyester, polyethylene terephthalate
, Thermoplastic polyester elastomer, and various other
Select and use thermoplastic polymer alloy, etc.
It is possible.

Among the above-mentioned thermoplastic resins, polyphenylene sulfide (hereinafter abbreviated as PPS) resin is mentioned as one having excellent heat resistance and excellent mechanical strength. The PPS resin may be represented by the following chemical formula 1, but the one represented by the chemical formula 2 below is commercially available from Philips Petroleum Company, USA under the trade name of "Ryton", and its manufacturing method is U.S. Pat. No. 3,354,129.
It is disclosed in Japanese Patent Publication No. 45-3368. According to it, the PPS resin is produced by reacting p-dichlorobenzene and sodium disulfide in N-methylpyrrolidone under pressure conditions at 160 to 250 ° C., and there is no cross-linking in the resin. Those having various degrees of polymerization, such as those having a partial cross-linking property, can be freely produced by a post heat treatment step, and those having a straight-chain nourishing structure without a crosslinked structure can also be produced. As described above, as the PPS resin, it is possible to arbitrarily select and use a resin having an appropriate melt viscosity characteristic for the intended solvent blend, and it is also a preferable material in the present invention.

[0011]

[Chemical 1]

[0012]

[Chemical 2]

The fluororesin in the present invention is a tetrafluoroethylene resin (hereinafter abbreviated as PTFE), ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene. -Hexafluoropropylene copolymer, polytrichlorofluoroethylene, polytetrafluoroethylene-chlorotrifluoroethylene resin, vinylidene fluoride resin and the like can be mentioned, but PTFE is particularly suitable. The PTFE may be a powder for molding as its form, or may be a so-called fine powder for a solid lubricant, and as a commercially available example, Teflon 7J, TL manufactured by DuPont Mitsui Fluorochemical Co., Ltd.
P-10, Asahi Glass Co., Ltd .: Fluon G163, Daikin Industries Co., Ltd .: Polyflon M15, Lubron L5 and the like.

The tin oxide used in the present invention may be either stannous oxide (SnO) or stannic oxide (SnO ₂ ). These are usually in the form of powder, and various appearances can be obtained by the production method, but they can be used without particularly limiting such a shape. The particle size in the case of powder is 0.1 to 100.
The range of μm is preferable, and more preferably 0.5 to 60 μm.
m. This is because it is not suitable in terms of technology and cost for obtaining powder having a particle size of less than 0.1 μm, and a large diameter exceeding 100 μm is not preferable because the friction and wear characteristics are not stable.

In the present invention, the amount of fluororesin is 5 to.
The reason for limiting the content to 30% by volume is that if it is less than 5% by volume, the lubricating properties are poor, and if it exceeds 35% by volume, the formability is remarkably impaired. The reason for limiting the amount of tin oxide to 3 to 35% by volume is that the lubricating properties are poor outside this range, and if it exceeds 35% by volume, the composition obtained becomes extremely brittle.

Here, the method of mixing the additives having a fixed blending ratio is not particularly limited, and a method that is generally widely used, for example, a resin as a main component and other various raw materials are individually added. Or a Henschel mixer,
After appropriately dry-mixing with a mixer such as a ball mill or a tumbler mixer, supply it to an injection molding machine or a melt extrusion machine with good melt mixing properties, or melt it beforehand with a hot roll, kneader, Banbury mixer, melt extruder, etc. A method such as mixing may be used. Further, in molding the composition of the present invention, the method is not particularly limited, and it may be a usual method such as compression molding, extrusion molding, injection molding, or after the composition is melt-mixed and then jet-milled. It is also possible to pulverize with a freeze pulverizer and classify it to a desired particle size, or to perform fluidized dip coating, electrostatic powder coating, etc. using the powder obtained without classifying. It is also possible to disperse the obtained powder in a solvent and perform spray coating or dip coating.

Various additives may be added to the lubricating composition containing the thermoplastic resin of the present invention as a main component, as long as the lubricating properties are not deteriorated. In addition, in order to further improve the lubricity, various abrasion resistance improvers may be added. Preferred examples of such abrasion resistance improvers include aromatic polyamide fibers, graphite, aromatic polyester resins and the like.

[0018]

The above-mentioned composition of the present invention is obtained by using a fluororesin and tin oxide in combination as essential components,
A sliding film with good lubricity is formed on the surface of the sliding mating material, and even if the mating material is a soft metal such as an aluminum alloy, it does not damage it and shows good lubricating properties.

[0019]

EXAMPLES First, the raw materials used in Examples and Comparative Examples are collectively shown as follows. The blending ratio of each component is% by volume.

(1) PPS resin (made by Tososa Steel Co., Ltd .: PPS # 160) (2) PPS resin (made by Kureha Chemical Co., Ltd .: KPS-W20)
5) (3) Nylon 66 (manufactured by Toray Industries: Amilan CM3001)
N) (4) Polyacetal (manufactured by Polyplastics: Duracon M90-02) (5) Tin oxide: SnO (manufactured by Wako Pure Chemical Industries, Ltd .: Reagent) (6) Tetrafluoride ethylene resin (Mitsui DuPont Fluorochemical Co., Ltd.) (Teflon 7J) (7) Aromatic polyamide fiber (Teijin: Conex fiber, 1 mm) (8) Aromatic polyester resin (Sumitomo Chemical Co., Ltd .:
Econol E101M) (9) Graphite (Nippon Graphite Co., Ltd .: ACP) (10) Copper oxide: CuO (Wako Pure Chemical Industries, Ltd .: Reagent) [Examples 1 to 3] Raw materials were blended in the proportions shown in Table 1. . When molding the composition, first, the raw materials are thoroughly mixed with a Henschel mixer, supplied to a twin-screw melt extruder, extruded under the melt-mixing conditions shown in Table 2 to granulate, and the obtained pellets are injected into an injection molding machine. And a ring-shaped test piece having an outer diameter of 35 mm, an inner diameter of 25 mm and a width of 6 mm was molded under the injection molding conditions shown in Table 2, and the following high temperature radial friction and wear test was performed using this test piece.

(A) High-temperature radial friction and wear test: An aluminum alloy (A5056) cylindrical mating member was fitted on the coaxial outer periphery of a rotating shaft driven in a sealed atmosphere of 200 ° C., and the outer periphery of this mating member was fitted. A ring-shaped test piece rotatably fitted to the peripheral surface of the mating member with a pressure of 2.7 kgf / cm ² and a torque meter attached to the rotary shaft.
After continuously rotating for 168 hours so that the peripheral speed is 3 m / min,
Abrasion amount of test piece (mg), torque of rotating shaft (kgf ・ c
m) was measured and the degree of damage to the mating material was observed. Regarding the degree of damage, a transition film is formed on the mating material and it is not damaged (marked with ○), slightly damaged (marked with △) or damaged (×)
It is represented by a three-level evaluation (mark). The results obtained are summarized in Table 3.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

[Table 3]

Comparative Examples 1 to 5 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 1, various characteristics were obtained, and the obtained results are shown in Table 3. I also wrote it down.

[Examples 4 to 5] The raw materials were mixed in the proportions shown in Table 1. In molding, first, the raw materials were thoroughly mixed with a Henschel mixer, then fed to a twin-screw extruder, extruded under the melt-mixing conditions shown in Table 2, granulated, and the pellets fed to an injection molding machine, Under the injection molding conditions shown in Table 2, inner diameter 17 mm, outer diameter 21 mm, length 10 m
A ring-shaped test piece of m was molded. A friction wear test was conducted using this ring-shaped test piece, and the results are summarized in Table 4.

(B) Friction and wear test: A thrust type wear tester was used, aluminum alloy A5056 was used as a sliding mating material, sliding speed was 32 m / min, and load was 3.1 kgf / cm ^2.
Under the above conditions, a continuous test was conducted for 100 hours to examine the friction coefficient, the wear coefficient and the degree of damage to the mating material. The evaluation method of the degree of damage is shown in two stages, with the one not damaging the mating material being marked with O and the one damaging the mating material being marked with x.

[0028]

[Table 4]

[Comparative Examples 6 and 7] Under the compounding ratios, mixing conditions and molding conditions shown in Tables 1 and 2, test pieces similar to those of Examples 4 and 5 were prepared and the above-mentioned test (b) was conducted. The coefficient of friction, the coefficient of wear, and the degree of damage to the mating material were investigated.

From the results shown in Table 3, in Comparative Examples 1 to 5, the wear amount and the rotating torque are all large, and in Comparative Examples 1, 2, 4 and 5, the mating material after the continuous rotation is largely damaged. It was On the other hand, in Examples 1 to 3, both the wear amount and the rotation torque are small, and it is understood that the aluminum alloy of the mating material is not damaged.

From the results shown in Table 4, Comparative Examples 6 and 7
In both cases, the wear coefficient was large, and the degree of damage to the mating material was also large. On the other hand, in Examples 4 and 5, the wear coefficient was small, and the aluminum alloy of the mating material was not damaged.

[0032]

[Effect] As described above, the lubricating resin composition of the present invention has excellent wear resistance against a soft material such as an aluminum alloy as a sliding partner, and such sliding partner material is not damaged. Therefore, it can be said that it has extremely excellent physical properties as a sliding material such as a bearing material. Further, since a thermoplastic resin is used, it can be easily molded by melt molding, and if a heat resistant resin such as PPS resin is adopted, abrasion resistance is required with a soft material as a sliding partner material under high temperature conditions. It also has the advantage of being a cool fit.

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Claims (1)

[Claims] 1. A lubricating resin composition comprising a thermoplastic resin and 5 to 35% by volume of a fluororesin and 3 to 35% by volume of tin oxide.