JP2999844B2 - Composition for operation, lubrication and fluid coupling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a working fluid composition for durable fluid couplings , especially for fan clutches or viscous couplings.

[0002]

2. Description of the Related Art For example, a fluid coupling includes a viscous coupling and a fan clutch (fan coupling). The viscous coupling includes a plurality of inner plates arranged so as to be movable toward a drive shaft and a spacer. A plurality of outer plates fixed to the driven side so as to keep a constant interval are alternately combined and housed in the housing, and as a viscous fluid for torque transmission,
It is constructed by filling an organopolysiloxane oil of 1000 cSt to 300,000 cSt (25 ° C.), and a shear force, that is, a shear torque is applied to the plate group due to a difference in rotation speed between the drive shaft side and the driven shaft side. Is generated to transmit torque to the driven shaft.

[0003] A fan clutch, especially a fluid coupling type clutch, is mounted on the tip of a pump shaft, and the groove on the disk surface on the pump shaft side and the groove on the wheel surface on the fan side are engaged with each other. A so-called labyrinth is formed in the body, and the disk has a structure in which it rotates while being immersed in an organopolysiloxane oil of 50 cSt to 20,000 cSt (25 ° C.) in the body. Due to the characteristics of the siloxane oil, the rotation power is transmitted to the wheel side to rotate the fan, and the maximum rotation can be limited without increasing the rotation of the fan used for cooling the radiator to a certain speed or more. Things.

In recent years, organopolysiloxane oils such as dimethylpolysiloxane and phenyl group-containing methylphenylpolysiloxane have been used as hydraulic system hydraulic fluids and working fluids for fluid coupling, and those having a generally high viscosity index (VI) have been used. Although it is used, it is difficult to stably maintain the torque transmission capability for a long time under severe use conditions such as high temperature. This is due to the low stability of the organopolysiloxane oil, especially at high temperatures. Therefore, there is an urgent need to improve the stability of a working fluid composition containing an organopolysiloxane oil as a main component. Therefore, this kind of operation
To prevent the oxidizing and gelling effects of the fluid composition, the organopolysiloxane oil can be used, for example, with iron octanoe-
Although antioxidants such as phenylamine derivatives and ferrocene derivatives have been added, a certain gelling prevention effect at high temperatures can be obtained, but the viscosity increases when used continuously in actual fluid couplings. Is actually happening.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a stable working fluid composition which is excellent in preventing thermal decomposition and gelation.

[0006]

SUMMARY OF THE INVENTION Therefore, the operation of the present invention is described.
The fluid composition is characterized by adding a specific antiwear agent to the organopolysiloxane.

As the organopolysiloxane, a compound represented by the formula

[0008]

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Wherein R represents the same or different, optionally halogenated, hydrocarbon radical having 1 to 18 carbon atoms, and n is an integer from 1 to 3000. It is. If the fluid coupling is a viscous coupling, 1000 cSt to 300,000 cSt (25 ° C)
Is used, and in the case of fan coupling, 50 cSt to 20,000 cSt (25 cSt).
° C) organopolysiloxane is used.

R represents 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, aryl groups such as phenyl group and naphthyl group, benzyl group, 1-phenylethyl group and 2-phenylethyl group Aralkyl, o-, m-, p-diphenyl and other aryl, o-, m-, p-chlorophenyl, 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 A halogenated hydrocarbon group such as Particularly, 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 preferable. Mixtures may be used.

The present invention is characterized in that an anti-wear agent, particularly a phosphorus-based or sulfur-based anti-wear agent, is added to the organopolysiloxane.

As the phosphorus-based antiwear agent, general formulas (1) to (1)
Examples of (6) include those having the following structures, and a compound containing at least one of them is effective.

[0013]

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(Wherein, R _{1 to} R ₄ are hydrogen or C 1
To 20 monovalent hydrocarbon groups, preferably a linear or branched alkyl group, an aryl group, an aralkyl group, an araryl group, or a halogenated hydrocarbon group; and R _{5 to} R ₇ are carbon atoms. A divalent hydrocarbon group of the formulas 1 to 6, preferably a linear or branched alkyl group, an aryl group, an aralkyl group, an araryl group, or a halogenated hydrocarbon group, wherein X _{1 to} X ₄ and Y are oxygen atoms Or a sulfur atom which may be the same or different, but R _{1 to} R ₄ may be directly bonded to a phosphorus atom without via Y, and n is 0 to 2
Wherein, when n is 0, X ₂ and X ₃ both represent a sulfur atom. ) Bisphosphoric acid esters,
Bisthiophosphate-based or bisdithiophosphate-based antiwear agents are also effective.
Are preferred from the viewpoints of surface adsorption to metals and solubility in organopolysiloxanes.

Bisphosphate esters are those in which X ₁ , X ₂ , X ₃ and X ₄ in the general formula (1) are all oxygen atoms.
Bisuchio phosphate system _{X 1, X 2, X 3} , 4 of the X ₄
When one to three are oxygen atoms and the rest are sulfur atoms, the bisdithiophosphate type is X ₁ , X ₂ , X ₃ ,
X ₄ is the case where all are sulfur atoms.

As the bisphosphate ester, bisthiophosphate ester or bisdithiophosphate ester wear inhibitors, those represented by the following general formulas (2), (3) and (4) are similarly used. It is valid.

[0017]

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Wherein R ₁ -R ₇ , X ₁ -X ₄ , Y and n
Represents the same content as in the general formula (1). )

[0019]

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

[0021]

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(Wherein R ₁ and R ₂ are hydrogen, having 1 to 2 carbon atoms)
0 is a monovalent hydrocarbon group, R ₈ is a hydrocarbon group having at least one ester bond having 1 to 20 carbon atoms, X ₁ , X _1
2 and Y are oxygen atoms or sulfur atoms, which may be the same or different. It should be noted that R ₁ to R 4 in the general formulas (1) to (4)
R ₄ includes a phenyl group and an alkylated phenyl group from the viewpoint of heat resistance.

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

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

[0025]

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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, etc .; lauryl acid phosphate, stearyl acid phosphate, di-phosphate
There are acidic phosphates such as 2-ethylhexyl phosphate.

The compound represented by the structural formula (2) includes
There are triarylphosphorothionate and the like, for example, triphenylphosphorothionate and alkyldiaryl phosphorothionate.

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

The compound represented by the structural formula (6) includes
And trilauryl thiophosphite.

Among them, triaryl phosphate,
Alternatively, a compound having a structure of triarylphosphorothionate has a remarkable effect on thermal stability.

In the general formula (6), R ₃ —Y _b —P = X _a (where 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, halogenated carbon It represents a hydrogen group and may be the same or different. The compound represented by ()) is also effective.

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

[0034]

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[0035]

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The following are specific compounds.

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

The compound represented by the structural formula (2) includes
and n-butyl-n-dioctyl phosphinate.

In addition,

[0040]

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The following are specifically mentioned.

The compound represented by the structural formula (1) includes
Hexamethylphosphoric triamide and the like.

The compound represented by the structural formula (2) includes
And dibutyl phosphoramidate.

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

The use ratio of the phosphorus-based antiwear agent is preferably 0.01 to 5% by weight, and more preferably 0.1 to 3% by weight, based on the weight of the organopolysiloxane. The phosphorus-based abrasion inhibitors may be used alone, but may be used in combination with each other in the above general formulas or in combination of two or more of the general formulas.

Next, diphenyl sulfide, diphenyl disulfide, di-n-butyl sulfide, di-n-butyl disulfide, di-tert-
Sulfides such as dodecyl disulfide and di-tert-dodecyl trisulfide, sulfurized fats and oils such as sulfurized palm oil and sulfurized dipentene, thiocarbonates such as xanthic disulfide, primary alkyl zinc thiophosphate, secondary Zinc thiophosphates such as zinc alkyl thiophosphate, zinc alkyl-allyl thiophosphate and zinc allyl thiophosphate can be used. The amount of the antiwear agent used is 0.01 to 0.01% based on the organopolysiloxane.
To 5% by weight, preferably 0.1 to 3% by weight.

The working fluid composition of the present invention may further contain an antioxidant. Such antioxidants include, for example, dioctyldiphenylamine, phenyl-
α-naphthylamine, alkyldiphenylamine, N-
Nitrosodiphenylamine, phenothiazine, N, N '
-Dinaphthyl-p-phenylenediamine, acridine,
Amine antioxidants such as N-methylphenothiazine, N-ethylphenothiazine, dipyridylamine, diphenylamine, phenolamine, 2,6-di-t-butyl-α-dimethylaminoparacresol; 2.6-di-
t-butylparacresol, 4.4'-methylenebis (2.6-di-t-butylphenol), 2.6-di-
Phenol antioxidants such as t-butylphenol; organic iron salts such as iron octoate, ferrocene and iron naphthoate; organic cerium salts such as cerium naphthoate and cerium toluate; zirconium It is preferable to use an organic metal compound based antioxidant such as an organic zirconium salt such as octoate. The above antioxidants may be used alone, but may be used in such a manner that a synergistic effect is exhibited by using two or more kinds in combination.

The proportion of the antioxidant used is preferably 0.001 to 5% by weight, and more preferably 0.01 to 2% by weight, based on the weight of the organopolysiloxane.

Further, various additives such as a metal deactivator and a corrosion inhibitor may be added to the working fluid composition of the present invention.

[0050]

The conventional working fluid composition has been improved mainly by improving the antioxidant from the viewpoint of preventing the thickening effect due to thermal deterioration accompanying the use at high heat. However, when the working fluid composition to which the antioxidant is added is applied to an actual fluid coupling, a viscosity increase still occurs.

The present inventors have considered that the cause cannot be solved simply by improving the effect of the antioxidant, and as a result of examining the cause, the metal contact between the disks in the viscous coupling is extremely large. Found to have an effect. That is, it is considered that the new surface of the metal plate generated by the abrasion from the metal contact acts as a catalyst for the organopolysiloxane degradation and acts on the degradation of the viscous coupling fluid.

Therefore, the present invention provides a viscous coupling fluid containing an anti-wear agent to form a film on a newly formed metal surface to suppress the catalytic action of the newly formed metal surface.
It can almost eliminate the phenomenon of thickening 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 an extremely large effect. That is, it is considered that the metal used as the material acts as a catalyst for the degradation of the organopolysiloxane and acts to increase the viscosity of the working fluid composition for a fan clutch.

Therefore, the present invention provides an operation for a fan clutch.
By adding a wear inhibitor to the fluid composition and forming a film on the metal surface to suppress the catalytic action of the metal, the thickening development of the working fluid composition for a fan clutch can be almost eliminated.

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

Further, in the working fluid composition of the present invention, when used together with an antioxidant, the heat resistance can be further increased, and the durability of the working fluid composition can be improved.

[0057]

[Reference Example 1] Dimethyl silicone (viscosity 1000 mm ² / s, 2
5 ° C.), 1.0 g of diphenylamine as an antioxidant
% Of working fluid , and tricresyl phosphate as an antiwear agent was added at the following addition ratio, and the working fluid composition was added to the fluid coupling at 25 ° C. at a filling volume of 30 ml. Filled.

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

After the lapse of time, the result of measuring the change in torque is shown in the following table. In the table below, the case where no wear inhibitor is added is also shown.

[0060]

[Table 1]

[0061]

[Reference Example 2] Dimethyl silicone (viscosity 1000 mm ² / s, 2
5%), 1.0% by weight of 4,4'-methylenebis (2,6-di-t-butylphenol) as an antioxidant,
The working fluid composition prepared by adding the anti-wear agent diphenyl disulfide at the following addition ratio was tested in the same manner as in Reference Example 1 .

The results are shown in the table below.

[0063]

[Table 2]

[0064]

Example 1 Dimethyl silicone (viscosity 10,000 mm ² / s,
25 ° C)

[0065]

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The bisdithiophosphate represented by the formula:
The working fluid composition for viscous coupling, which was adjusted by changing the addition amount as shown in the following table, was added at 25 ° C., 8
It was filled into a viscous coupling having 111 disks at a filling factor of 5% by volume.

The viscous coupling has a rotational difference of 50r.
pm, kept in a bath maintained at 130 ° C., 50
Driving for hours.

After the lapse of time, the results of measuring the change in viscosity and the change in torque are shown in the following table. In the table below, the case where 1.0% by weight of diphenylamine was further added as an antioxidant is also shown.

[0069]

[Table 3]

[0070]

Example 2 Dimethyl silicone (viscosity 10,000 mm ² / s,
25 ° C)

[0071]

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The bisdithiophosphate represented by the formula:
The working fluid composition for viscous coupling, which was adjusted by changing the addition amount as shown in the following table, was added at 25 ° C., 8
It was filled into a viscous coupling having 111 disks at a filling factor of 5% by volume.

The viscous coupling has a rotational difference of 50r.
pm, kept in a bath maintained at 130 ° C., 50
Driving for hours.

After the lapse of time, the results of measuring the change in viscosity and the change in torque are shown in the following table. In the table below, the case where 1.0% by weight of diphenylamine was further added as an antioxidant is also shown.

[0075]

[Table 4]

[0076]

Example 3 The antiwear agent in Example 1 was replaced by a compound represented by the formula

[0077]

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The working fluid composition for viscous coupling, which was changed to the dithiophosphate shown by
Filled into a viscous coupling having 111 disks at a filling rate of 85% by volume at ° C.

The viscous coupling has a rotational difference of 50r.
pm, kept in a bath maintained at 130 ° C., 50
Driving for hours.

After the lapse of time, the results of measuring the change in viscosity and the change in torque are shown in the following table.

[0081]

[Table 5]

[0082]

The working fluid composition of the present invention is excellent in heat resistance and therefore hardly changes in viscosity, and is excellent in durability.

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI // C10N 30:06 30:08 40:04 (56) References JP-A-64-65195 (JP, A) JP-A-61-12794 ( JP, A) JP-A-2-91196 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C10M 169/04 C10M 107/50 C10M 137/00-137/14

Claims (4)

(57) [Claims] 1. An organopolysiloxane to which at least one anti-wear agent selected from bisphosphates, bisthiophosphates, bisdithiophosphates, and derivatives thereof represented by the following general formula (A) is added. A working fluid composition, characterized in that: Embedded image (Wherein, R _{1 to} R ₄ are hydrogen, a monovalent hydrocarbon group having 1 to 20 carbon atoms, R _{5 to} R ₇ are a divalent hydrocarbon group 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 a phosphorus atom without via Y, and n represents an integer of 0 to 2 However, when n is 0, X ₂ and X ₃ both represent a sulfur atom.) 2. The method according to claim 1, wherein at least one anti-wear agent selected from a phosphoric acid ester, a thiophosphoric acid ester, and a dithiophosphoric acid ester represented by the following general formula (B) or a derivative thereof is added to the organopolysiloxane. A working fluid composition characterized by the following: Embedded image (Wherein R ₁ and R ₂ are hydrogen, a monovalent hydrocarbon group having 1 to 20 carbon atoms, R ₈ is a hydrocarbon group having at least one ester bond having 1 to 20 carbon atoms, X ₁ and X ₂ And Y are oxygen or sulfur and may be the same or different.) 3. For a fluid coupling which is a fan coupling.
Any of claims 1 or 2, characterized in that the need 1
The working fluid composition according to the above item. 4. A fluid coupling which is a viscous coupling.
3. A method as claimed in claim 1, wherein the method is used.
The working fluid composition according to claim 1.