JPH0450297A - Composition for fluid coupling - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a composition for a clutch.

[Conventional technology]

Organopolysiloxane oils such as dimethylpolysiloxane and phenyl group-containing methylphenylpolysiloxane are used as working fluids in fan clutches.

A fan clutch, especially a fluid coupling type clutch, is attached to the tip of the pump shaft, and the grooves on the disk surface on the pump shaft side are engaged with the grooves on the wheel surface on the fan side, forming a so-called labyrinth between them. The disc has a structure in which it rotates inside the body while being immersed in organopolysiloxane oil.The disc rotates as the pump rotates, and the characteristics of the organopolysiloxane oil transmit rotational power to the wheel side, which drives the fan. It rotates, and can limit the maximum rotation of the fan used for cooling the radiator without increasing the rotation above a certain speed.

Organopolysiloxane oil with a high viscosity index (VI) is generally used in this type of clutch, but it is difficult to maintain stable torque transmission over a long period of time under severe operating conditions such as high temperatures. Have difficulty. this is,
This is due to the low heat resistance stability of organopolysiloxane oil, especially at high temperatures. Therefore, there is an urgent need to improve its heat resistance stability.

Antioxidants such as iron octanoate, phenylamine derivatives, and ferrocene derivatives have been added to organopolysiloxane oils in order to prevent their oxidation and gelling effects. Although adding an agent can provide a certain effect of preventing gelation under high heat, actual fan clutches actually have the problem of increased viscosity due to continuous use.

[Problem to be solved by the invention]

An object of the present invention is to provide a stable composition for fluid couplings that is excellent in preventing thermal decomposition and gelation.

[Means to solve the problem]

Therefore, the composition for fluid couplings of the present invention is a composition for fluid couplings using organopolysiloxane as a base oil, in which a sulfur-based wear inhibitor and/or a zinc thiophosphate-based wear inhibitor is added to the phosphorus-based wear inhibitor. It is characterized by what it did.

The organopolysiloxane has the formula % (wherein R represents the same or different optionally halogenated hydrocarbon group having from 1 to 18 carbon atoms, and n is an integer from 1 to 3000. ).

As R, methyl group, ethyl group, n-propyl group, l
-propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group, neopentyl group, hexyl group,
Alkyl groups such as heptyl group, octyl group, decyl group, and octadecyl group, aryl group such as phenyl group, naphthyl group, benzyl group, 1-phenylethyl group, 2
-aralkyl group such as phenylethyl group, o-1mp
-Araryl group such as diphenyl group, 0m-1p-
Chlorphenyl group, 0-1m-1p bromphenyl group,
3. 3. 3-) Lifluoropropyl group, 1. 1.
1. 3. 3. halogenated hydrocarbon groups such as 3-hexafluoro-2-propyl, heptafluoroisopropyl and heptafluoro-n-propyl. In particular, as the group R, fluorinated hydrocarbon groups having 1 to 8 carbon atoms excluding aliphatic unsaturated groups are advantageous, and methyl groups and phenyl groups are also advantageous, and methylpolysiloxanes and phenylpolysiloxanes are also preferable. Mixtures may also be used.

The present invention is characterized in that a combination of a phosphorus-based anti-wear agent, a sulfur-based anti-wear agent, and/or a zinc thiophosphate-based anti-wear agent is added as an anti-wear agent to this organopolysiloxane.

As a phosphorus-based wear inhibitor, the general formula is as follows:
Compounds containing at least one of (2) are effective. In the following formula, R may be hydrogen, an alkyl group, an aryl group, or a benzyl group, and may be the same or different.

R-0\ R-0\ \ ■　　　　RP=0 ■ \ R-P=0 ■ R-0-P=S ■ R-0-P=S \ ■　　　　RP=S ■ Hiroshi R-P=S R-3\ ■　R-3-P=O R-8/ ■ Rzu\ @R-3-P=O R/ R-3\ @R-3-P=S R-8/ (R)2N/ 2-o/ R-3\ (R)′ゝ＼ (R)・N\ (R)・ゝ＼ Specific compounds are shown below.

Compounds represented by the above structural formula include triaryl phosphates, such as benzyl diphenyl phosphate, aryl diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, ethyl diphenyl phosphate, and tributyl phosphate. , dibutyl phosphate, talesyl diphenyl phosphate, dicresyl phenyl phosphate, ethyl phenyl diphenyl phosphate, diethylphenyl phenyl phosphate, propylphenyl diphenyl phosphate, dipropylphenyl phenyl phosphate, triethylphenyl phosphate,
Tripropylphenyl phosphate, butylphenyl diphenyl phosphate, dibutylphenyl phenyl phosphate, tributylphenyl phosphate,
There are phosphoric acid esters such as a propylphenylphenyl phosphate mixture and a butylphenylphenyl phosphate mixture, and acidic phosphoric esters such as lauryl acid phosphate, stearyl acid phosphate, and di-2-ethylhexyl phosphate.

Examples of the compound represented by the structural formula (2) include di-n-butylhexylphosphonate.

The compound represented by the structural formula (■) is n-butyl-n-
Examples include dibutyl phosphate.

Examples of the compound represented by the structural formula (2) include triarylphosphorothionate, such as triphenylphosphorothionate and alkyldiarylphosphorothionate.

Examples of the compound represented by the structural formula (2) include triisopropyl phosphite and diisopropyl phosphite.

Examples of the compound represented by the structural formula (2) include trilaurylthiophosphite.

Examples of the compound represented by the structural formula (2) include hexamethylphosphoric triamide.

Examples of the compound represented by the structural formula include dibutylphosphoramidate.

Among the compounds represented by the structural formula (2), there are compounds in which R is an octyl group.

Among the compounds represented by the structural formula (2), there are compounds in which R is an octyl group.

Among these, compounds having the structure of triaryl phosphate or triaryl phosphorothionate have remarkable effects in terms of thermal stability.

The proportion of the phosphorus anti-wear agent used is 0.01% to 5% by weight, preferably 0.1% by weight based on the organopolysiloxane.
It is preferable to use it in an amount of 3% to 3% by weight.

Further, the above-mentioned phosphorus-based wear inhibitors may be used alone, but two or more types can also be used in combination.

In addition, examples of sulfur-based wear inhibitors include diphenyl sulfide, diphenyl disulfide, dibutyl sulfide,
Sulfides such as di-n-butyl disulfide, di-tert-dodecyl disulfide, di-tert-dodecyl trisulfide, sulfurized oils and fats such as sulfurized palm oil and sulfurized dipentene, and thiocarbonates such as xantic disulfide. Zinc thiophosphate-based antiwear agents such as zinc thiophosphate, primary alkylthiophosphate, zinc alkyl-allylthiophosphate, zinc allylthiophosphate, etc. can be used. The total usage ratio of the sulfur-based wear inhibitor and/or the zinc thiophosphate wear-resistant agent to the phosphorus-based wear inhibitor is 0.01 to 5% by weight, preferably 0.
．． It is preferable to use 1 to 3% by weight, and the proportion of the phosphorus-based antiwear agent to the entire antiwear agent is preferably 5 to 95% by weight.

Moreover, an antioxidant may be further added to the fluid coupling composition of the present invention.

Examples of antioxidants include dioctyl diphenylamine, phenyl-α-naphthylamine, alkyldiphenylamine, N-nitrosodiphenylamine, phenothiazine, N, N'-dinaphthyl-p-phenyl diamine, acridine, N-methylphenothiazine, N-
Ethylphenothiazine, dipyridylamine, diphenylamine, phenolamine, 2,6-di-t-butyl-
Amine antioxidants such as α-dimethylamino para-cresol, 2.6-di-t-butyl para-cresol, 4.4
- Phenolic antioxidants such as methylenebis(2,6-di-t-butylphenol) and 2,6-di-t-butylphenol, organic iron salts such as iron octoate, ferrocene, and iron naphtonite, cerium naphtonite, and cerium tol. It is preferable to use organic metal compound antioxidants such as organic cerium salts such as ate, organic siliconium salts such as siliconium octoate, and the like. Further, the above antioxidants may be used alone, but they can also be used in combination of two or more to produce a synergistic effect.

The usage ratio of the above antioxidant is 0.001 to 5% by weight, preferably 0.01 to 5% by weight based on the organopolysiloxane.
It is recommended to use 2% by weight.

[Function] In conventional compositions for fluid couplings, from the viewpoint of preventing thickening effect due to thermal deterioration accompanying use under high heat,
Improvements have been made mainly by improving fluid coupling compositions by adding antioxidants. However, when a fluid coupling composition containing an antioxidant is applied to an actual fluid coupling, an increase in viscosity still occurs.

The present inventors considered that the cause could not be solved simply by improving the effect of antioxidants, and as a result of examining the cause,
We have discovered that the contact between silicone oil and materials such as wheels and disks in fluid couplings has a very large effect.

That is, it seems that the metal used as the material acts as a catalyst for the deterioration of the organopolysiloxane, thereby acting on the deterioration of the fluid coupling composition.

As anti-wear agents, phosphorus-based anti-wear agents, sulfur-based anti-wear agents, zinc thiophosphate-based anti-wear agents, etc. are effective to the extent that they can be added alone to the fluid coupling composition, but the present invention By blending a specific amount of a phosphorus-based wear inhibitor, a sulfur-based wear inhibitor, and/or a zinc thiophosphate-based wear inhibitor into a composition for fluid joints, the synergistic effect is obtained.
They discovered and completed that it is possible to suppress the catalytic action of the metal by forming a film on the metal surface, thereby almost eliminating the thickening phenomenon.

It is thought that phosphorus-based, sulfur-based, zinc thiophosphate-based anti-wear agents, etc. exhibit adsorption to metals in a specific temperature range depending on their thermal stability. In the present invention, the environmental temperature within the fluid coupling main body is thought to vary over a wide range depending on its operating conditions, and this can be accommodated by combining and adding anti-wear agents with different adsorption properties.

Moreover, by using an antioxidant together with the fluid coupling composition of the present invention, the heat resistance can be further improved, and the durability of the fluid coupling composition can be improved.

[Example 1] Dimethyl silicone (viscosity 1000 mm'/s, 25°C
), 1.0% by weight of diphenylamine was added as an antioxidant, and tricresyl phosphate (phosphorus-based) and dibenzyl disulfide (sulfur-based) were added as anti-wear agents.
A composition for a fluid coupling prepared by adding the following at the following addition rate was filled into a fluid coupling at 25° C. and in a filling amount of 30 mf.

Fluid coupling is 1 at rotation speed 650 Or pm
I drove for 00 hours.

The results of measuring changes in viscosity and torque after the test are shown in the table below. In addition, in the table below, a case where an anti-wear agent was added separately is also shown as a comparative example.

As can be seen from the above table, when a surface wear inhibitor is added to a fluid coupling composition at the same time, there is a decrease in viscosity change and torque change compared to when either one of the wear inhibitors is added. It can be seen that the effects have improved in both cases.

Furthermore, in the fluid coupling composition in Example 1,
preparing a composition for a fluid coupling without adding an antioxidant;
The results of measuring viscosity changes and torque changes in the same manner as above are shown in the table below. In addition, in the table below, a case where an anti-wear agent was added separately is also shown as a comparative example.

(Left below) In addition, a composition for a fluid coupling was prepared and tested in the same manner as in Example 1, and the viscosity change and torque change were measured. The results are shown in the following table.

As can be seen from the table above, it can be seen that similar compositions for fluid couplings can be obtained without adding an antioxidant.

Furthermore, in the fluid coupling composition in Example 1, 0.20% by weight of di-5ec-butyldithiophosphate (zinc thiophosphate) anti-wear agent was further added to prepare a fluid coupling composition, and the same composition as above was prepared. When tested, there was a viscosity change of +2% and a -torque change of 10 degrees, indicating that by combining phosphorus-based, sulfur-based, and zinc thiophosphate-based wear inhibitors, an excellent composition for fluid couplings can be made. .

[Example 2] In the sample of Example 1, instead of the dibenzyl disulfide (sulfur-based) anti-wear agent, sulfurized olefin was added as a sulfur-based anti-wear agent at the following addition ratio [Example 3] The sample of Example 1 In place of the tricresyl phosphate (phosphorus-based) anti-wear agent, aminodibutyl phosphonate (phosphorus-based) anti-wear agent was added in the following ratio to prepare a fluid coupling composition, and the same procedure as in Example 1 was carried out. The following table shows the results of testing and measuring changes in viscosity and torque.

In addition, the table below also shows a case where no sulfur-based material was added as a comparative example.

(Left below) [Example 4] In the sample of Example 1, zinc di-5ec-butyl ditheophosphate (
A fluid coupling composition was prepared by adding zinc thiophosphate (Zinc thiophosphate) in the following proportions, and tested in the same manner as in Example 1. The results of measuring changes in viscosity and torque are shown in the following table.

In addition, the table below also shows a case where phosphorus is not added as a comparative example.

[Example 5] In the sample of Example 1, instead of the tricresyl phosphate (phosphorus-based) wear inhibitor, a triphenyl phosphorothionate (phosphorus-based) wear inhibitor was added in the following ratio to create a fluid joint. A composition was prepared and tested in the same manner as in Example 1,
The results of measuring changes in viscosity and torque are shown in the table below.

In addition, the table below also shows a case where no sulfur-based material was added as a comparative example.

[Effects of the Invention] The fluid coupling composition of the present invention includes a combination of a phosphorus-based wear inhibitor, a sulfur-based wear inhibitor, and/or a zinc thiophosphate-based wear inhibitor added to an organopolysiloxane as a base oil. As a result, in operation in a fluid coupling, heat resistance can be further improved, there is almost no change in viscosity, and durability can be achieved.

Claims (2)

[Claims] (1) A composition for fluid couplings using organopolysiloxane as a base oil, characterized in that a sulfur-based wear inhibitor and/or a zinc thiophosphate-based wear inhibitor is added to a phosphorus-based wear inhibitor. Composition. (2) In the composition for fluid couplings using organopolysiloxane as a base oil, it is confirmed that a sulfur-based wear inhibitor and/or a zinc thiophosphate-based wear inhibitor and an antioxidant are added to the phosphorus-based wear inhibitor. Characteristic composition for fluid couplings.