JPH06172774A - Composition for working, lubrication and fluid coupling - Google Patents

Abstract

PURPOSE:To obtain the subject composition excelling in heat resistance, scarcely undergoing a viscosity change and excelling in durability by adding an antiwear agent such as a (thio)phosphoric ester to an organopolysiloxane. CONSTITUTION:0.01-5wt.%, based on the organopolysiloxane, bis(thio)phosphoric ester of general formula I (wherein R1 to R7 are each a 1-6C bivalent hydrocarbon group; X1 to X4 and Ys are each O and S and may be the same or different from each other; R1 to R4 may be bonded to the P not through Y; and (n) is 0-2, provided that X2 and X3 are each S when (n)=0) or phosphoric ester of general formula II (wherein R1 and R2 are each H or a 1-20C monovalent hydrocarbon group; R8 is a 1-20C hydrocarbon group having at least one ester bond; and X1, X2 and Ys are each O and S and may be the same or different from each other) is added to an organopolysiloxane. 0.001-5wt.%, based on the organopolysiloxane, antioxidant may be added to this composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a durable composition for actuating / lubrication / fluid coupling, particularly for fan clutches, and for viscous couplings.

[0002]

2. Description of the Related Art For example, a fluid coupling has a viscous coupling, a fan clutch (fan coupling), etc. The viscous coupling has a plurality of inner plates arranged so as to be movable toward a drive shaft and a spacer. By alternately combining a plurality of outer plates fixed to the driven side so as to keep a constant interval and accommodating in the housing, as a viscous fluid for torque transmission,
It is configured by filling an organopolysiloxane oil of 1000 cSt to 300,000 cSt (25 ° C.), and the plate group is subjected to a shearing force, that is, a shearing torque, due to the difference in rotational speed between the driving shaft side and the driven shaft side. Is generated and torque is transmitted to the driven shaft.

A fan clutch, especially a fluid coupling type clutch, is attached to the tip of a pump shaft, and a groove on the disk surface on the pump shaft side and a groove on the wheel surface on the fan side mesh with each other. A so-called labyrinth is formed in the disk, and the disk has a structure that rotates while being immersed in an organopolysiloxane oil of 50 cSt to 20,000 cSt (25 ° C) in the body, and the disk rotates as the pump rotates, Due to the characteristics of siloxane oil, the fan is rotated by transmitting rotational power to the wheel side, and the maximum rotation can be limited without increasing the rotation of the fan used to cool the radiator to a certain speed or more. It is a thing.

In recent years, organopolysiloxane oils such as dimethylpolysiloxane and phenyl group-containing methylphenylpolysiloxane have been used as hydraulic fluids and hydraulic fluid working fluids, and generally have a high viscosity index (VI). Although used, it is difficult to maintain stable torque transmission over a long period of time under severe operating conditions such as high temperature. This is due to the low stability of the organopolysiloxane oil, especially at high temperatures. Therefore, in the composition for actuation / lubrication / fluid coupling mainly composed of organopolysiloxane oil,
There is an urgent need to improve its stability. Therefore, in order to prevent the oxidation and gelling action of this kind of operation / lubrication / fluid coupling composition, antioxidants such as iron octanoate, phenylamine derivatives, and ferrocene derivatives are added to organopolysiloxane oils. However, although a certain gelation-preventing effect at a high temperature can be obtained, the problem that the viscosity increases when it is continuously used in an actual fluid coupling actually occurs.

[0005]

The present invention is excellent in preventing thermal decomposition and gelation, and has stable operation, lubrication, and
An object is to provide a composition for a fluid coupling.

[0006]

Therefore, the composition for actuation / lubrication / fluid coupling of the present invention is characterized by adding an antiwear agent to organopolysiloxane.

The organopolysiloxane has the formula

[0008]

[Chemical 3]

## STR3 ## wherein R represents the same or different, optionally halogenated hydrocarbon radical having 1 to 18 carbon atoms, n being an integer from 1 to 3000. Is. If the fluid coupling is a viscous coupling, 1000 cSt to 300,000 cSt (25 ° C)
Organopolysiloxanes of 50 cSt to 20,000 cSt (25
C.) organopolysiloxanes are used.

R is a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl group, an n-pentyl group, a neopentyl group,
Alkyl groups such as hexyl group, heptyl group, octyl group, decyl group, and octadecyl group, phenyl groups, aryl groups such as naphthyl group, benzyl group, 1-phenylethyl group, 2-phenylethyl group, etc. Aralkyl group, o-, m-, araryl group such as p-diphenyl group, o-, m-, p-chlorophenyl group, o-, m
-, P-bromophenyl group, 3,3,3-trifluoropropyl group, 1,1,1,3,3,3-hexafluoro-2-propyl group, heptafluoroisopropyl group and heptafluoro-n-propyl group A halogenated hydrocarbon group such as a group. In particular, as the group R, a fluorinated hydrocarbon group having 1 to 8 carbon atoms excluding an aliphatic unsaturated group is advantageous, a methyl group and a phenyl group are advantageous, and a methylpolysiloxane and a phenylpolysiloxane are preferred. Mixtures may be used.

The present invention is characterized in that an organopolysiloxane is added with an antiwear agent, particularly a phosphorus-based or sulfur-based antiwear agent.

The phosphorus-based antiwear agent is represented by the general formula (1)
Examples of (6) include those having the following structures, and compounds containing at least one of them are effective.

[0013]

[Chemical 4]

(In the formula, R _{1 to} R ₄ are hydrogen or have 1 carbon atom.
To 20 monovalent hydrocarbon groups, preferably linear or branched alkyl groups, aryl groups, aralkyl groups, araryl groups, and halogenated hydrocarbon groups as the hydrocarbon groups, and R _{5 to} R ₇ are carbon atoms. A divalent hydrocarbon group of formulas 1 to 6, preferably a linear or branched alkyl group, aryl group, aralkyl group, araryl group or halogenated hydrocarbon group, wherein X _{1 to} X ₄ and Y are oxygen atoms Or sulfur atoms which may be the same or different, R _{1 to} R ₄ may be directly bonded to the phosphorus atom without interposing Y, and n is 0 to 2
In the case where n is 0, both X ₂ and X ₃ represent a sulfur atom. ) Phosphoric acid ester system represented by
Bisthiophosphoric acid ester-based or bisdithiophosphoric acid ester-based antiwear agents are also effective, and among them, those having 1 to 10 carbon atoms.
The ones are preferable from the viewpoints of surface adsorption to metals and solubility to organopolysiloxanes.

The bisphosphate ester is a case where X ₁ , X ₂ , X ₃ and X ₄ in the general formula (1) are all oxygen atoms,
The bisthiophosphoric acid ester type has four types of X ₁ , X ₂ , X ₃ and X ₄ .
When 1 to 3 of them are oxygen atoms and the rest are sulfur atoms, the bisdithiophosphate ester system is X ₁ , X ₂ , X ₃ ,
This is the case where all X ₄ are sulfur atoms.

As the bisphosphoric acid ester-based, bisthiophosphoric acid ester-based, or bisdithiophosphoric acid ester-based antiwear agents, those represented by the following general formulas (2), (3), and (4) are also the same. It is valid.

[0017]

[Chemical 5]

(Wherein R _{1 to} R ₇ , X _{1 to} X ₄ , Y and n
Shows the same contents as in the general formula (1). )

[0019]

[Chemical 6]

(In the formula, R _{1 to} R ₄ are hydrogen or a carbon number of 1
To 20 monovalent hydrocarbon groups, preferably linear or branched alkyl groups, aryl groups, aralkyl groups, araryl groups, and halogenated hydrocarbon groups as the hydrocarbon groups, and R ₅ and R ₆ are carbon atoms. A divalent hydrocarbon group of formulas 1 to 6, preferably a linear or branched alkyl group, aryl group, aralkyl group, araryl group or halogenated hydrocarbon group, wherein X _{1 to} X ₄ and Y are oxygen atoms Or sulfur atoms which may be the same or different but R _{1 to} R ₄ may be directly bonded to the phosphorus atom without interposing Y, and n is 0 to 2
Represents the integer. )

[0021]

[Chemical 7]

(In the formula, R ₁ and R ₂ are hydrogen and have ₁ to ₂ carbon atoms.
A monovalent hydrocarbon group of 0, R ₈ is a hydrocarbon group having 1 to 20 carbon atoms and having at least one ester bond, X ₁ , X
₂ and Y are oxygen atoms or sulfur atoms and may be the same or different. ) Incidentally, R _{1 of} the general formulas (1) to (4)
Examples of R ₄ include a phenyl group and an alkylated phenyl group from the viewpoint of heat resistance.

Further, in the general formula (5) (RY) ₃ -P = X _a (wherein X and Y are sulfur atoms or oxygen atoms, a is 0 or 1,
R represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group, aryl group, aralkyl group, araryl group or halogenated hydrocarbon group as the hydrocarbon group, which may be the same or different. May be. The compounds shown in () are also effective.

Specific examples of the compound represented by the general formula (5) include:

[0025]

[Chemical 8]

Specific compounds are shown below.

Examples of the compound represented by the above structural formula (1) include triaryl phosphate and the like. For example, benzyl diphenyl phosphate, allyl diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, ethyl diphenyl phosphate. ,
Tributyl phosphate, dibutyl phosphate,
Cresyl diphenyl phosphate, dicresyl phenyl phosphate, ethyl phenyl diphenyl phosphate, diethyl phenyl phenyl phosphate, propyl phenyl diphenyl phosphate, dipropyl phenyl phenyl phosphate, triethyl phenyl phosphate, tripropyl phenyl phosphate, butyl phenyl Phosphate esters such as diphenyl phosphate, dibutyl phenyl phenyl phosphate, tributyl phenyl phosphate, propyl phenyl phenyl phosphate mixture, butyl phenyl phenyl phosphate mixture, lauryl acid phosphate, stearyl acid phosphate, di-
There are acidic phosphoric acid esters such as 2-ethylhexyl phosphate.

As the compound represented by the structural formula (2),
There are triarylphosphorothionates and the like, for example, triphenylphosphorothionate, alkyldiarylphosphorothionates and the like.

As the compound represented by the structural formula (5),
Examples include triisopropyl phosphite, diisopropyl phosphite, and the like.

As the compound represented by the structural formula (6),
Examples include trilauryl thiophosphite.

Among these, triaryl phosphate,
Alternatively, a compound having a structure of triarylphosphorothionate has a remarkable effect in terms of thermal stability.

In the general formula (6), R ₃ —Y _b —P═X _a (wherein X and Y are sulfur atoms or oxygen atoms, a is 0 or 1,
b is an integer of 0 to 2, R is hydrogen, or a hydrocarbon group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group, aryl group, aralkyl group, araryl group, or halogenated carbon group as a hydrocarbon group. It represents a hydrogen group and may be the same or different. The compounds shown in () are also effective.

Specific examples of the compound represented by the general formula (6) include:

[0034]

[Chemical 9]

[0035]

[Chemical 10]

Specific compounds are shown below.

Examples of the compound represented by the structural formula (1) include di-n-butylhexylphosphonate.

As the compound represented by the structural formula (2),
n-butyl-n-dioctylphosphinate and the like.

In addition,

[0040]

[Chemical 11]

Specific examples include the following.

As the compound represented by the structural formula (1),
Hexamethylphosphoric triamide and the like.

As the compound represented by the structural formula (2),
There are dibutyl phosphoramidate and the like.

Among the phosphorus-based antiwear agents mentioned above, the general formulas (1) to (4) are particularly suitable for the viscous coupling fluid.

The proportion of the phosphorus-based antiwear agent used is 0.01 to 5% by weight, preferably 0.1 to 3% by weight, based on the organopolysiloxane. The above phosphorus-based antiwear agents may be used alone, or may be used in a combination of the compounds represented by the above general formulas or two or more compounds represented by the general formulas.

Next, as a sulfur-based antiwear agent, diphenyl sulfide, diphenyl disulfide, di-n-butyl sulfide, di-n-butyl disulfide, di-tert-
Sulfides such as dodecyl disulfide, di-tert-dodecyl trisulfide, sulfurized spalm oil, sulfurized fats and oils such as sulfalized dipentene, thiocarbonates such as xanthic disulfide, zinc primary alkylthiophosphate, secondary Zinc thiophosphates such as zinc alkyl thiophosphate, zinc alkyl-allyl thiophosphate, zinc allyl thiophosphate and the like can be used. The proportion of antiwear agent used is 0.01 with respect to the organopolysiloxane.
It is recommended to use -5% by weight, preferably 0.1-3% by weight.

An antioxidant may be further added to the composition for actuation / lubrication / fluid coupling of the present invention. Examples of this type of antioxidant include dioctyldiphenylamine, phenyl-α-naphthylamine, alkyldiphenylamine, N-nitrosodiphenylamine, phenothiazine, N, N′-dinaphthyl-p-phenylenediamine, acridine, N-methylphenothiazine, N-ethyl. Phenothiazine, dipyridylamine, diphenylamine, phenolamine, 2,6-di-t-butyl-α-
Amine-based antioxidants such as dimethylaminoparacresol, 2.6-di-t-butylparacresol, 4.4 '
-Methylenebis (2.6-di-t-butylpheno-
Phenol) such as 2.6-di-t-butylphenol
-Based antioxidants, organic iron salts such as iron octoate, ferrocene and iron naphthoate, organic cerium salts such as cerium naphthoate and cerium toluate, and organic zirconium salts such as zirconium octoate. It is preferable to use an organometallic compound-based antioxidant such as The above-mentioned antioxidants may be used alone, or may be used in combination of two or more so as to exert a synergistic effect.

The above-mentioned antioxidant is used in an amount of 0.001 to 5% by weight, preferably 0.01 to 2% by weight, based on the weight of the organopolysiloxane.

Various additives such as metal deactivators and corrosion inhibitors may be added to the composition for actuation / lubrication / fluid coupling of the present invention.

[0050]

[Function] In the conventional composition for actuation / lubrication / fluid coupling, from the viewpoint of preventing the thickening effect due to the thermal deterioration due to the use under high heat, the improvement is focused on the improvement of the antioxidant. It has been planned. However, when the composition for actuation / lubrication / fluid coupling to which an antioxidant is added is applied to an actual fluid coupling, the viscosity still rises.

The inventors of the present invention have considered that the cause cannot be solved only by improving the effect of the antioxidant, and as a result of investigating the cause, in the viscous coupling, the metal contact between the discs is extremely large. It was found to have an impact. That is, it is considered that the new surface of the metal plate caused by the abrasion due to the metal contact acts as a catalyst for the deterioration of the organopolysiloxane and acts on the deterioration of the fluid for viscous coupling.

Therefore, in the present invention, an antiwear agent is added to the fluid for viscous coupling to form a film on the newly-formed metal surface to suppress the catalytic action by the newly-formed metal surface.
It is possible to almost eliminate the thickening phenomenon of the viscous coupling fluid.

On the other hand, in the fan clutch, it has been found that the contact between the material such as the wheel and the disk and the silicone oil has a great influence. That is, it is considered that the metal used as a material acts as a catalyst for the deterioration of the organopolysiloxane and acts to increase the viscosity of the fan clutch composition.

Therefore, in the present invention, an anti-wear agent is added to the composition for fan clutches to form a film on the metal surface to suppress the catalytic action of the metal, so that the thickening development of the composition for fan clutches is almost eliminated. Is something that can be done.

The fluid of the present invention can also be used in compositions using polysiloxanes for shock absorbers, dampers, lash adjusters, auto tensioners, G-sensors and the like.

Further, in the composition for working / lubricating / fluid coupling of the present invention, the heat resistance can be further enhanced by using it together with an antioxidant, and the durability of the composition for working / lubricating / fluid coupling can be improved. It is possible to improve the sex.

[0057]

Example 1 Dimethyl silicone (viscosity 1000 mm ² / s, 2
Diphenylamine as an antioxidant at 1.0
The composition for working / lubrication / fluid coupling prepared by adding tricresyl phosphate as an antiwear agent at the following addition ratio was added to the fluid coupling at 25 ° C and a filling amount of 30 ml during fluid coupling. Filled.

The fluid coupling has a rotation speed of 6500r.
It was driven for 50 hours at pm.

The results of measuring the change in torque after the passage of time are shown in the following table. In the table below, the case where no antiwear agent is added is also shown.

[0060]

[Table 1]

[0061]

Example 2 Dimethyl silicone (viscosity 1000 mm ² / s, 2
4,4'-methylenebis (2,6-di-t-butylphenol) 1.0 wt% as an antioxidant at 5 ° C),
A working / lubrication / fluid coupling composition prepared by adding an antiwear agent diphenyl disulfide in the following addition ratio was tested in the same manner as in Example 1.

The results are shown in the table below.

[0063]

[Table 2]

[0064]

Example 3 Dimethyl silicone (viscosity 10000 mm ² / s,
25 ° C) as an antiwear agent

[0065]

[Chemical 12]

The bisdithiophosphate ester represented by
The composition for viscous coupling prepared by changing the addition amount as shown in the table below was prepared at 25 ° C. and 85% by volume.
At a filling factor of 1 to fill a viscous coupling with 111 discs.

The viscous coupling has a rotational speed difference of 50r.
pm, keep in a constant temperature bath at 130 ℃, 50
I drove for hours.

The results of measuring the change in viscosity and the change in torque after the passage are shown in the table below. In the table below, the case where 1.0% by weight of diphenylamine is further added as an antioxidant is also shown.

[0069]

[Table 3]

[0070]

Example 4 Dimethyl silicone (viscosity 10000 mm ² / s,
25 ° C) as an antiwear agent

[0071]

[Chemical 13]

The bisdithiophosphate ester represented by
The composition for viscous coupling prepared by changing the addition amount as shown in the table below was prepared at 25 ° C. and 85% by volume.
At a filling factor of 1 to fill a viscous coupling with 111 discs.

The viscous coupling has a rotational speed difference of 50r.
pm, keep in a constant temperature bath at 130 ℃, 50
I drove for hours.

The results of measuring the change in viscosity and the change in torque after the passage are shown in the table below. In the table below, the case where 1.0% by weight of diphenylamine is further added as an antioxidant is also shown.

[0075]

[Table 4]

[0076]

Example 5 The anti-wear agent in Example 3 was replaced by the formula

[0077]

[Chemical 14]

The composition for viscous coupling prepared by changing the amount of the dithiophosphoric acid ester represented by the formula (3) and varying the addition amount as shown in the following table was added at a filling rate of 85% by volume at 25 ° C. Filled into a viscous coupling with a disc.

The viscous coupling has a rotational speed difference of 50r.
pm, keep in a constant temperature bath at 130 ℃, 50
I drove for hours.

The results of measuring the change in viscosity and the change in torque after the passage are shown in the table below.

[0081]

[Table 5]

[0082]

The composition for actuation / lubrication / fluid coupling of the present invention is excellent in heat resistance and therefore hardly changes in viscosity and excellent in durability.

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Claims (6)

[Claims] 1. A composition for working / lubrication / fluid coupling, comprising an organopolysiloxane and an antiwear agent added thereto. 2. Operation / lubrication characterized by adding an antiwear agent and an antioxidant to organopolysiloxane.
Composition for fluid coupling. 3. The working / lubrication / fluid according to claim 1, wherein the antiwear agent is a bisphosphoric acid ester, a bisthiophosphoric acid ester, a bisdithiophosphoric acid ester represented by the following general formula (A), or a derivative thereof. Composition for joints. [Chemical 1] (In the formula, R _{1 to} R ₄ are hydrogen, a monovalent hydrocarbon group having 1 to 20 carbon atoms, R _{5 to} R ₇ are divalent hydrocarbon groups having 1 to 6 carbon atoms, X _{1 to} X ₄ and Y is an oxygen atom or a sulfur atom and may be the same or different, but R _{1 to} R ₄ may be directly bonded to the phosphorus atom without interposing Y, and n represents an integer of 0 to 2. However, when n is 0, both X ₂ and X ₃ represent a sulfur atom.) 4. The composition for working / lubrication / fluid coupling according to claim 1, wherein the antiwear agent is a phosphoric acid ester, a thiophosphoric acid ester, a dithiophosphoric acid ester represented by the following general formula (B) or a derivative thereof. . [Chemical 2] (In the formula, R ₁ and R ₂ are hydrogen, a monovalent hydrocarbon group having 1 to 20 carbon atoms, R ₈ is a hydrocarbon group having 1 to 20 carbon atoms and having at least one ester bond, X ₁ and X ₂ And Y are oxygen atoms or sulfur atoms and may be the same or different.) 5. The composition for working / lubrication / fluid coupling according to claim 1, 2 or 3, wherein the fluid coupling is a fan coupling. 6. The composition for working / lubrication / fluid coupling according to claim 1, 2 or 3, wherein the fluid coupling is a viscous coupling.