JPS59179655A - Oil-containing synthetic resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has improved frictional and wear characteristics and moldability and reduced coefficient of friction, by blending a liquid lubricant, a specified additive, a nonionic surfactant and a solid lubricant with a synthetic resin. CONSTITUTION:The titled compn. is obtd. by blending 2-15pts.wt. liquid lubricant, 0.1-2pts.wt. at least one member selected from higher fatty acids, their salts and their alkyl esters (e.g. stearic acid, zinc stearate or butyl stearate) and further 0.2-15pts.wt. nonionic surfactant (A) and 5-30pts.wt. solid lubricant (B) such as graphite with 100pts.wt. synthetic resin such as polyacetal. By blending component A, the liquid lubricant is prevented from separating, and the frictional and wear characteristics as well as moldability can be improved. By blending component B, the coefficient of friction can be further reduced in conjunction with the liquid lubricant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oleoresin synthetic resin, t, J1 composition.

Oil-containing synthetic resin compositions take advantage of their properties such as low friction and wear resistance, and are used in parts that require good sliding, such as bearings, cams, gears, and sliding plates, in other words, sliding parts. has been done.

Conventionally, such oil-containing synthetic resin compositions include 3, for example, as disclosed in Japanese Patent Publication No. 46-4.2217,
It is known to mix lubricating oil with powder such as polyacecool or polyamide and knead it in an extruder or injection molding machine to make it oil-impregnated, but the lubricating oil tends to separate during kneading, and it lacks processing stability. When feeding pelletized material using a screw in an injection molding machine, the material tends to be poorly bited into the screw, and this method is unsuitable for high-cycle molding.

Also, as disclosed in Japanese Patent Publication No. 4.6-5321, after mixing powder such as polyacetal in excess lubricating oil at a temperature equal to or higher than the melting point of the resin.

It is also known that the resin that has been cooled and precipitated is turned into powder, but the process is complicated and it is difficult to adjust the oil content to a predetermined value.

Furthermore, it is also known to use a porous material such as activated carbon as an oil-absorbing carrier, and to mix the oil-absorbed porous material with a thermoplastic resin and knead it into pellets using a twin-screw press ratio machine. Oil-absorbing carriers such as 1 friction.

Regarding the wear characteristics, there is a problem in that it acts as a negative factor, and it is not possible to sufficiently improve the friction and wear characteristics, especially under conditions of high load and high speed sliding.

In view of this point, the present invention has been developed by blending a liquid lubricant and auxiliary agents such as higher fatty acids, higher fatty acid salts, and higher fatty acid alkyl esters into a synthetic resin, as well as a small amount of nonionic surfactant.

It prevents liquid lubricant from separating, improves friction and wear characteristics, and improves moldability.

Appropriate amount of solids? By blending a lubricant, an oil-containing synthetic resin composition is provided which, in combination with the liquid lubricant described above, further reduces the coefficient of friction.

That is, the oil-containing synthetic resin composition according to the present invention contains 2 to 15 parts by weight of a liquid lubricant and one of higher fatty acids, higher fatty acid salts, higher fatty acid alkyl esters, or 100 parts by weight of synthetic resin. 2+i is o, i to 2.0 parts by weight, and the nonionic surfactant is 0.2 to 15 parts by weight.2 The solid lubricant is 5 to 30 parts by weight.

As the synthetic resin, those having excellent self-lubricating properties and wear resistance such as 5-polyacecool, polyamide, polybutylene terephthalate, polypropylene, polyethylene, polysulfone, polycarbonate, and polyarylate are used.

Liquid lubricants include aromatic lubricants such as spindle oil, turbine oil, machine oil, and dynamo oil.

Naphthenic lubricating oil, paraffinic lubricating oil or hydrocarbon,
Commonly used lubricating oils are used, such as synthetic lubricating oils such as esters, polyglycols, and silicones. This liquid lubricant is 2 to 15 parts by weight per 100 parts by weight of the synthetic resin.
It is added in parts by weight, but if it is less than 2 parts by weight, the friction and wear characteristics cannot be sufficiently improved, and if it exceeds 15 parts by weight, the physical properties of the synthetic resin will be impaired, which is not preferable.

Stearic acid is an auxiliary agent for higher fatty acids.

Higher fatty acids such as zinc stearate and butyl stearate, higher fatty acid salts, and higher fatty acid alkyl esters are used. Such auxiliary agents 1 have a high affinity with the synthetic resin and 5 enhance the chemical interaction between the synthetic resin and the liquid lubricant.
Acts as an internal or external lubricant. This auxiliary agent is 9 synthetic resin 1 o.

It is blended in 0.1 to 2.0 parts by weight, but 0.
．． If the amount is less than 1 part by weight, the above chemical interaction cannot be sufficiently enhanced, leading to problems in the molding process, especially in the plasticizing process in the injection molding machine.

A problem arises in that the liquid 7rJJ/il agent is likely to separate. On the other hand, if the amount of the auxiliary agent exceeds 2.0 parts by weight, bleeding of the auxiliary agent will occur, causing problems in molding processing and use of the molded product.

As the nonionic surfactant, an alkylphenol type, sorbitan ester type, or ether type is used. This nonionic surfactant enhances the chemical interaction between the synthetic resin and the liquid lubricant and acts as an internal lubricant or an external lubricant. The nonionic surfactant is blended in an amount of 0.2 to 15 parts by weight per 100 parts by weight of one synthetic resin, but if it is less than 0.2 parts by weight, the above chemical interaction cannot be sufficiently enhanced and the molding process is difficult. Particularly during the plasticizing process, separation of liquid lubricants is likely to occur.

If the amount exceeds 15 parts by weight, bleeding of the nonionic surfactant will occur, causing problems in processing and use of molded products.

The above-mentioned higher fatty acid-based auxiliary agent and nonionic surfactant are:
Both have similar effects, but by using both together, they can synergistically improve the friction and wear characteristics of the oil-containing synthetic resin composition, as well as the moldability. be. In other words, if higher fatty acid-based auxiliary agents and nonionic surfactants are used alone, there is a limit to the amount they can be added to each synthetic resin. Although there is a limit to the ability to improve the physical properties of the composition, the combination of the two makes it possible to incorporate more additives that act as internal or external lubricants into the synthetic resin. and.

By blending this nonionic surfactant, the liquid lubricant is uniformly dispersed in the form of microparticles in the oil-containing synthetic resin composition, and even if the amount of liquid lubricant added is increased, separation of the liquid lubricant during molding will not occur. Since poor biting of the material into the screw of the injection molding machine is prevented, together with the action of the higher fatty acid-based auxiliary agent, processing stability 5 friction characteristics and wear characteristics can be improved.

In particular, when only a higher fatty acid-based auxiliary agent is added.

Insufficient compatibility between synthetic resin and liquid lubricant.

Molding becomes virtually impossible. On the other hand, when only a nonionic surfactant is added, although the coefficient of friction can be reduced and the wear resistance improved to some extent, problems remain in terms of compatibility between the synthetic resin and the liquid a lubricant.

The solid lubricant exhibits the effect of increasing lubricity in combination with the liquid lubricant, and graphite, molybdenum disulfide, ethylene tetrafluoride resin, etc. are used as the solid lubricant. This solid lubricant is blended in 5 to 30 parts by weight with respect to 100 parts by weight of the synthetic resin, but if it is less than 5 parts by weight, the lubricity cannot be sufficiently improved, and if it exceeds 30 parts by weight, the lubricity is not improved. Not only can you not expect much improvement, but you also have the problem that the molded product becomes brittle and difficult to process.

The graphite used is natural graphite (V4 flakes).

Scale-like, earth-like) 3 artificial graphite, etc. are used, and the solid lubricant is made as fine as possible in particle size in order to improve dispersibility and lubricity.

The present invention will be explained below based on two examples and a comparative test with a comparative example.

<Example> The blending ratios in this example are as follows.

Polyacecool resin 100 parts by weight (Duracon M 90-00 flakes manufactured by Polyplastics Co., Ltd.) Mechanic oil 4 parts by weight Zinc stearate 0.5 parts by weight Nonionic surfactant 1.0 parts by weight Fluorinated ethylene resin
Using a material obtained by mixing 10 parts by weight of the above ingredients in a super mixer, kneading and pelletizing in a twin-screw extruder,
A test piece was created using an injection molding machine.

Comparative example 1> The blending ratios in this example are as follows.

Polyacecool resin 100 parts by weight (Duracon M 90-00 flakes manufactured by Polyplastics Co., Ltd.) Mechanic oil 4 parts by weight Zinc stearate 0.5 parts by weight Nonionic surfactant 1.0 parts by weight 1. Mixed ingredients in 1. Using the mixed materials, which were kneaded and pelletized using a twin-screw extruder, test pieces were prepared using an injection molding machine.

Comparative example 2> The blending ratios in this example are as follows.

Polyacecool resin 100 parts by weight (Duracon M 90-00 flakes manufactured by Polyplastics Co., Ltd.) Mechanic oil 4 parts by weight Zinc stearate 0.5 parts by weight Activated carbon
1.0 parts by weight of the above compounding ingredients were mixed in a super mixer in the same manner as in the examples, kneaded and pelletized in a twin-screw extruder, and a test piece was prepared in an injection molding machine.

In the comparative test, friction and wear characteristics were investigated using a journal test. The test piece has an inner diameter of 8 iris and an outer diameter of 151. This test specimen shaft was fitted into a cylinder body having a length of 1511 mm, and the shaft was rotated at a predetermined speed while a load was applied in the vertical direction of the shaft.

The friction coefficient and the amount of wear on the test pieces were measured. The shaft is 345C and has a surface roughness of 3S. The test results are shown in the table below. In addition, under the test conditions, the load was 5 kg/c
a, the speed is 2Qm/min, and the test time is 100 hours.

As shown in this table, the coefficient of friction is lower in the example than in either Comparative Example 1.2.

Because solid lubricants contribute to lowering the coefficient of friction (I understand.

In this case, the lubricity of the sliding surface is maintained extremely well due to the synergistic effect of the solid lubricant exposed on the sliding surface of the test piece and the liquid lubricant supplied to this sliding surface from inside the specimen. It is recognized that an attempt has been made to reduce the above-mentioned coefficient of friction.

When graphite or molybdenum disulfide is used as a solid lubricant, the friction and wear characteristics are slightly inferior to those of tetrafluoroethylene resin, but graphite and molybdenum disulfide also improve friction when combined with liquid lubricants. This has a great effect on reducing the coefficient.

Furthermore, in the molding of the above test pieces, in the examples, no separation of oil during extrusion pelletization or failure of the pellets to be bitten into the screw of the injection molding machine was observed. On the other hand, in Comparative Example 2, oil separation and poor biting of the pellet into the screw were observed, and processing stability tended to be lacking.

Furthermore, the coefficient of friction decreases as the amount of nonionic surfactant increases; however, when the amount of nonionic surfactant increases, it exhibits a plasticizer-like effect.

The thermal deformation temperature of the molded product becomes low, causing the molded product to melt when running under high load. for example.

In Comparative Example 1, the amount of nonionic surfactant was 1
5 parts by weight, load 5 kg/cnt, speed 40
When tested under conditions of m/min, melting of the test piece was observed within a short period of time. Therefore, it can be seen that products containing a large amount of nonionic surfactant are mainly suitable for use at low loads.

The amount of nonionic surfactant added is preferably about 25% of the amount of liquid lubricant added. If it is less than 25%, the liquid lubricant will not be sufficiently soaked, and if it is more than 25%, the heat of the molded product will increase. Although the deformation temperature will decrease slightly, 12
Of course, it is possible to use it at 5% or more or less.

As described above, according to the present invention, a liquid lubricant and a higher fatty acid-based auxiliary agent are used for one synthetic resin.

By incorporating a small amount of nonionic surfactant, separation of liquid lubricant during molding process and failure to feed the material into the screw of the injection molding machine are prevented, improving process stability, and solid lubrication. By blending an appropriate amount of the agent, the above liquid if,! In combination with a lubricant, it is possible to reduce the coefficient of friction, and when applied to bearings, cams, gears, etc., an excellent effect can be obtained in that the friction and wear characteristics can be improved.

Continuation of page 1 1100 1100 27/18) (C08L 101100 1100 1102 27/18)

Claims (1)

[Scope of Claims] (1) 2 to 15 parts by weight of a liquid lubricant, a higher fatty acid, and a higher fatty acid salt per 100 parts by weight of a synthetic resin. 0.1 parts of one or two of higher fatty acid alkyl esters. ~2.0 parts by weight, 0.2 parts by weight of nonionic surfactant
15 parts by weight of a solid lubricant and 5 to 30 parts by weight of a solid lubricant.