JPH06220480A - Lubricating oil for shock absorber - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a lubricating oil for shock absorbers having excellent load resistance. [Structure] The lubricating oil for shock absorbers of the present invention has the general formula (1): (In the formula, R, R ′, and R ″ are a hydrocarbon group having 1 to 12 carbon atoms or a halogenated hydrocarbon group, x, y, and p are integers, x is 0 to 30, y is 1 to 30, p is 1 to 20), and is a mixed oil of a plurality of polyolefins having a viscosity ratio at 25 ° C. different by at least 1: 5, and a polyolefin oil having a viscosity at 25 ° C. of 5 cSt to 5000 cSt. Base oil, load-bearing additive and /
Alternatively, carbamates are added.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorber lubricating oil such as an auto tensioner oil.

[0002]

2. Description of the Related Art In an automobile, the rotation of an engine is used to rotate a camshaft timing pulley and a water pump pulley with a timing belt, and a hydraulic auto tensioner is used to maintain a constant belt tension. The belt has a long life and low noise.

A hydraulic type automatic tensioner has a structure in which a check ball and a spring for adjusting the oil movement by the movement of a rod are built in a cylinder, and a belt tension is made constant by pushing a tensioner idler by a spring through the rod. It is something to maintain.
When the engine speed rises, a high load is generated through the tensioner idler, and even if the rod tries to be pushed into the auto tensioner, the movement of the enclosed oil is blocked by a check ball to prevent high pressure. As a result, the rod is prevented from being pushed in, and on the contrary, when the belt becomes loose, the check ball is pushed open by the oil to allow the oil to move, and the spring pushes up the rod to keep the belt tension constant. It has the effect of maintaining.

[0004]

The oil used in such an autotensioner has an appropriate viscosity, has a small viscosity change with temperature, that is, has a high viscosity index, and has a heat resistance. Excellent load resistance and load resistance are required. To improve the viscosity index, it is generally considered to add a viscosity index improver to obtain a high viscosity index, or to use a base oil having a high viscosity index such as silicone oil.

However, the former one to which the viscosity index improver is added has a problem that the viscosity is lowered due to shearing or the like and the low temperature viscosity property is not good, which makes it difficult to put into practical use. When used as an oil, the viscosity index is high, but the lubricating oil properties are low, and the development of alkyl modification from the viewpoint of improving its lubricity and the development of antioxidants from the viewpoint of improving heat resistance have been promoted. Since there is a shortage, there is a problem that abrasion of the friction part occurs, and development of a lubricant for a shock absorber suitable as an autotensioner oil is required. An object of the present invention is to provide a shock absorber lubricating oil having excellent load resistance.

[0006]

The lubricating oil for shock absorbers of the present invention has the general formula (1).

[0007]

[Chemical 3]

(In the formula, R, R'and R "are hydrocarbon groups having 1 to 12 carbon atoms or halogenated hydrocarbon groups, x, y and p are integers, x is 0 to 30 and y is 1). ~ 30, p is 1
20), which is a mixed oil of a plurality of polyolefins having viscosity ratios at 25 ° C. different by at least 1: 5, and the viscosity of the mixed oil at 25 ° C. is 5 cSt to 50.
A polyolefin oil of 00 cSt is used as a base oil, and a load bearing additive and / or carbamate is added.

The lubricating oil for shock absorbers of the present invention is a mixed oil of a plurality of polyolefins represented by the above general formula (1) and having viscosity ratios at 25 ° C. different by at least 1: 5 or more. Has a viscosity of 5 cSt to 50 at 25 ° C.
A polyolefin oil and ester oil and / or an organopolysiloxane oil of 00 cSt are used as a base oil, and a load-bearing additive and / or a carbamate is added.

Furthermore, the shock absorber lubricant of the present invention is characterized in that an antioxidant is added to each of the shock absorber lubricants.

Hereinafter, the shock absorber lubricating oil of the present invention will be described in detail.

First, a polyolefin oil as a base oil is represented by the above general formula (1), and R in the general formula (1)
R ′ and R ″ are hydrocarbon groups having 1 to 12 carbon atoms, and are methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, t-butyl group,
Alkyl group such as n-pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, decyl group and octadecyl group, phenyl group, aryl group such as naphthyl group, benzyl group, 1-phenylethyl group , Aralkyl groups such as 2-phenylethyl group, o-, m-, p
-Alaryl groups such as diphenyl groups, 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-
It is a halogenated hydrocarbon group such as a propyl group. In particular, R, R ', and R "groups exclude aliphatic unsaturated groups 1
Preference is given to fluorinated hydrocarbon radicals having -8 carbon atoms, as well as alkyl radicals.

When the present invention uses the above polyolefins as a base oil, it is a mixed oil obtained by mixing a plurality of polyolefins having a viscosity ratio at 25 ° C. different by at least 1: 5, and the mixed oil at 25 ° C. Viscosity is 5c
By using St-5000 cSt as the base oil,
Improves viscosity-temperature characteristics when used as shock absorber lubricant,
It is possible to further prevent the occurrence of wear in the shock absorber.

The viscosity ratio of the plurality of polyolefins at 25 ° C. is at least 1: 5 or more, preferably 1: 5.
It is advisable to use a combination of 20 or more different polyolefins, and more preferably to combine 1: 100 or more different polyolefins. Mixing with a viscosity ratio below this range cannot improve the viscosity index, and cannot improve low-temperature viscosity characteristics.

Regarding the viscosity to be used in combination as a plurality of polyolefins having different viscosity ratios, and the mixing ratio thereof, the viscosity of the mixed polyolefin oil is from 5 cSt to 5000 cSt, preferably 50 cS.
There is no particular limitation as long as it is from t to 1000 cSt, but as a low-viscosity polyolefin, a viscosity at 25 ° C. is preferably 5 cSt to 1000 cSt, and as a high-viscosity polyolefin, preferably a viscosity at 25 ° C. is 100 cSt to 200,000 cSt. It is preferable to use one.

The ester oil which can be used in combination with the above polyolefin oil as the base oil is represented by the following general formula (2) to
A representative is the one represented by (7).

[0017]

[Chemical 4]

In the above general formulas (2) to (7), R and R '
Are hydrocarbon groups having 1 to 12 carbon atoms and halogenated hydrocarbon groups, such as methyl group, ethyl group, n-propyl group, i-
Alkyl groups such as propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, decyl group and octadecyl group, phenyl group, Aryl group such as naphthyl group, benzyl group, 1-phenylethyl group, 2-
Aralkyl groups such as phenylethyl group, o-, m-,
Alaryl groups such as p-diphenyl group, o-, m
-, P-chlorophenyl group, o-, m-, p-bromophenyl group, 3,3,3-trifluoropropyl group, 1,
Halogenated hydrocarbon groups such as 1,1,3,3,3-hexafluoro-2-propyl group, heptafluoroisopropyl group and heptafluoro-n-propyl group. Particularly preferred as R, R ', R "groups are fluorinated hydrocarbon groups having 1 to 8 carbon atoms excluding aliphatic unsaturated groups, and alkyl groups.

Preferably, the diester system represented by the general formula (4) is advantageous, and examples thereof include diisodecyl adipate, di-n-octyl adipate, di-2-ethylhexyl adipate and adipic acid-di-. Examples include adipic acid diesters such as isooctyl and adipic acid-di-sec-octyl, as well as azelaic acid diesters, sebacic acid diesters and dodecanedioic acid diesters.

Further, polyol esters such as trimethylolpropane trioleate and neopentyl glycol diolate represented by the above general formula (5) can be preferably used. These esters can be used alone or as a mixture.

As the organopolysiloxane, the average unit formula is

[0022]

[Chemical 5]

Wherein R has from 1 to 18 carbon atoms and is the same or different, optionally halogenated 1
A valent hydrocarbon group, and a is a number represented by 1.9 to 2.1.

R in this average unit formula is methyl group, ethyl group, n-propyl group, i-propyl group, n
-Butyl group, i-butyl group, t-butyl group, n-pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, decyl group, alkyl group such as octadecyl group, phenyl group, naphthyl group, etc. Aralkyl groups such as aryl group, benzyl group, 1-phenylethyl group and 2-phenylethyl group, o-, m-, araryl groups such as p-diphenyl group, o-, m-, p-chlorophenyl group, o-, m-, p-bromophenyl group, 3,
3,3-trifluoropropyl group, 1,1,1,3
Halogenated hydrocarbon groups such as 3,3-hexafluoro-2-propyl group, heptafluoroisopropyl group and heptafluoro-n-propyl group. In particular, as the R group, a fluorinated hydrocarbon group having 1 to 8 carbon atoms excluding an aliphatic unsaturated group and an alkyl group are preferable, and a mixture of the above-mentioned organopolysiloxanes having different R is preferable. May be used. The organopolysiloxane oil represented by the average unit formula has a viscosity at 25 ° C. of 5 cSt.
It is possible to preferably use one having a viscosity of up to 5000 cSt.

As the base oil in the lubricating oil for shock absorbers of the present invention, the above-mentioned mixed polyolefin oil is used alone as the base oil, or the above-mentioned ester oil and / or organopolysiloxane oil is mixed with the mixed polyolefin oil to obtain 25 ° C. The viscosity range may be adjusted to be 5 cSt to 5000 cSt. In this case, the proportion of the mixed polyolefin oil in the base oil is at least 40% by weight, preferably 60% by weight or more. The viscosity of the base oil in the present invention is 5 cSt to 5000 cSt, preferably 5 cSt.
It is 0 cSt to 1000 cSt.

The load-bearing additive may be a sulfur-based, zinc thiophosphate-based or phosphorus-based load-bearing additive, but is limited to phosphorus-based and zinc thiophosphate-based load-bearing additives in the present invention. . The phosphorus-based load-bearing additive is represented by the following general formulas (8) to (14), and compounds containing at least one of them are effective.

[0027]

[Chemical 6]

(In the formula, R _{1 to} R ₄ are hydrogen, or have 1 carbon atoms.
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 but 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 additives are effective, and among them, those having 1 to 10 carbon atoms are preferable from the viewpoint of surface adsorbability to metals and solubility in base oils.

The bisphosphoric acid ester is a case where X ₁ , X ₂ , X ₃ and X ₄ in the general formula (8) 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 additives, those represented by the following general formulas (9), (10) and (11) are also effective. Is.

[0031]

[Chemical 7]

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

[0033]

[Chemical 8]

(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. )

[0035]

[Chemical 9]

(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 in} the general formulas (8) to (11)
About R ₄ to R ₄ , a phenyl group and an alkylated phenyl group are preferable from the viewpoint of heat resistance.

Further, in the general formula (12) (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 (12) include:

[0039]

[Chemical 10]

Specific compounds are shown below.
Examples of the compound represented by the structural formula (1) in the general formula (12) include triaryl phosphate and the like. For example, benzyl diphenyl phosphate, allyl diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, and the like. 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 diphenyl phosphate, dibutyl phen Phosphate esters such as ruphenyl phosphate, tributyl phenyl phosphate, propyl phenyl phenyl phosphate mixture, butyl phenyl phenyl phosphate mixture, etc., and acidic such as lauryl acid phosphate, stearyl acid phosphate, di-2-ethylhexyl phosphate, etc. There are phosphate esters. Examples of the compound represented by the structural formula (2) include triarylphosphorothionate and the like, for example, triphenylphosphorothionate, alkyldiarylphosphorothionate and the like. Examples of the compound represented by the structural formula (5) include triisopropyl phosphite and diisopropyl phosphite. Examples of the compound represented by the structural formula (6) include trilauryl thiophosphite. Among them, a compound having a structure of triaryl phosphate or triaryl phosphorothionate is remarkably effective in terms of thermal stability.

[0041] Also, the general formula _{(13) (R-Y b} ) 3 -P = X a ( wherein X, Y is a sulfur atom or an oxygen atom, 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 (13) include:

[0043]

[Chemical 11]

Specific compounds are shown below.
Examples of the compound represented by the structural formula (1) in the general formula (13) include di-n-butylhexylphosphonate. Examples of the compound represented by the structural formula (2) include n-butyl-n-dioctylphosphinate. Other,

[0045]

[Chemical 12]

And the like. In the formula, R is a general formula (13).
The same as R in the above, and specifically includes the following. Examples of the compound represented by the structural formula (1) in [Chemical Formula 12] include hexamethylphosphoric triamide. Examples of the compound represented by the structural formula (2) include dibutylphosphoroamidate.

As the zinc thiophosphate-based load-bearing additive, zinc primary alkylthiophosphate, zinc secondary alkylthiophosphate, zinc alkyl-arylthiophosphate, zinc arylthiophosphate and the like can be used.

The load-bearing additive is used in the lubricating oil for shock absorbers in an amount of 0.01% by weight to 10.0% by weight, preferably 0.1% by weight to 5.0% by weight. The load bearing additives may be used alone or in combination of two or more.

Further, carbamates may be used as an additive together with the load bearing additive or in place of the load bearing additive. Examples of the carbamates include dithiocarbamate, dithiocarbamate derivatives, and metal salts of thiocarbamic acid. The proportion of carbamates used is 0.01% by weight to 10.0% in the lubricating oil for shock absorbers.
%, Preferably 0.01 to 3.0% by weight. The carbamates may be used alone or in combination of two or more.

An antioxidant may be added to the lubricating oil for shock absorbers of the present invention, if necessary. Examples of the antioxidant include dioctyldiphenylamine, phenyl-α-naphthylamine, alkyldiphenylamine, N-nitrosodiphenylamine, phenothiazine, N, N′-dinaphthyl-p-phenylenediamine, acridine, N-methylphenothiazine, N-ethylphenothiazine, Dipyridylamine, diphenylamine, phenolamine,
Amine-based antioxidants such as 2,6-di-t-butyl-α-dimethylaminoparacresol, 2.6-di-t-butylparacresol, 4.4′-methylenebis (2.6-
Di-t-butylphenol), phenolic antioxidants such as 2.6-di-t-butylphenol, organic iron salts such as iron octoate, ferrocene and iron naphthoate, and cerium naphthoate. -Organic compound-based antioxidants such as organic cerium salts such as cerium and cerium toluate, and organic zirconium salts such as zirconium octoate. The above antioxidants may be used alone,
By using two or more kinds in combination, they can be used so as to produce a synergistic effect. The proportion of the antioxidant used is 0.01% by weight to 1 in the lubricating oil for shock absorbers.
0.0% by weight, preferably 0.1% to 3.0% by weight
It is good to contain.

[0051]

In the conventional lubricants for shock absorbers such as autotensioner oils, from the viewpoint of preventing thickening action due to thermal deterioration due to use under high heat, improvement of antioxidants, and Alkyl modification of dimethyl silicone oil has been attempted from the viewpoint of improving lubricity. However,
When this conventional lubricating oil for shock absorbers is applied to an actual shock absorber, there still arises a problem that wear of the friction portion occurs.

As a base oil in a lubricant for a shock absorber, the present inventors mix polyolefins having different viscosities to form a base oil, or, if necessary, add an ester oil and / or an organo oil to the mixed polyolefin oil. By adding polysiloxane oil as a base oil and adding load-bearing additives and / or carbamates as a lubricant for shock absorbers, it was found that the occurrence of wear in shock absorbers such as auto tensioners can be eliminated. It is a thing. The shock absorber lubricating oil of the present invention can be used for shock absorber oil and the like in addition to auto tensioner oil.

The present invention will now be described with reference to examples.
The friction and wear tests adopted in Examples 1 and 2 and Comparative Examples 1 to 4 were carried out by using a vibration friction and wear tester in a point contact of a sphere / plane disc, and the measurement condition was a load of 50.
N, amplitude 2.5 mm, frequency 15 Hz, temperature 130 ° C. Observe friction coefficient and wear scar width after measurement for 30 minutes.
evaluated. Further, the friction and wear test adopted in Example 3 and Comparative Examples 5 to 6 was carried out by using a vibration friction and wear tester in a point contact of a sphere / plane disc, and the measurement conditions were a load of 30 N and an amplitude. It was 2.0 mm, the frequency was 70 Hz, and the temperature was 100 ° C., and the friction coefficient and the abrasion scar width after measurement for 30 minutes were observed and evaluated.

The .alpha.-olefin oligomer having a viscosity of 20 cSt at 25.degree.
Chemical Product SHF-21 (8 cSt, a
28% by weight of SHF-41 (31 cSt,
(at 25 ° C.) 72 wt% is mixed. The α-olefin oligomer having a viscosity of 8 cSt at 25 ° C. used in Example 3 is S manufactured by Mobil Chemical Products.
HF-21 was used as is. 2 used in Example 4
The α-olefin oligomer having a viscosity of 40 cSt at 5 ° C is SHF-41 manufactured by Mobil Chemical Products.
(31 cSt, at 25 ° C.) 54 wt% same as SHF-6
1 (55 cSt, at 25 ° C.) 46% by weight is mixed.

The ethylene-α-olefin oligomer having a viscosity of 500 cSt at 25 ° C. used in Examples 1 and 2 was the Lucant series HC-20 (337 cSt, at 25 ° C.) manufactured by Mitsui Petrochemical Co., Ltd. 57 wt% and same as HC-40 (880 cSt, at 25 ° C) 43 wt%
Is a mixture of. 25 ° C. used in Examples 3 to 4
The ethylene-α-olefin oligomer having a viscosity at 100,000 cSt is a Lucant series HC-2000 (100,000 cS manufactured by Mitsui Petrochemical Industry Co., Ltd.).
t, at 25 ° C.) was used as it was.

[0056]

Example 1 An α-olefin oligomer having a viscosity of 20 cSt at 25 ° C. and an ethylene-α-olefin oligomer having a viscosity of 500 cSt at 25 ° C. in a weight ratio of 2:
The mixture was mixed at a ratio of 8 to obtain a base oil having a viscosity of 220 cSt at 25 ° C. The following load-bearing additives or carbamates (A) to (F) were added to this base oil as shown in Table 1 below to prepare sample oils 1 to 10 and a friction wear test was conducted. The results are also shown in Table 1.

[0057]

Comparative Example 1 An organopolysiloxane oil having a viscosity of 220 cSt at 25 ° C. was used as a base oil, and the following load-bearing additives (D) to (F) were added as shown in Table 1 below. Was prepared and a friction wear test was carried out. The results are also shown in Table 1.

[0058]

Comparative Example 2 Using the same base oil as in Example 1, the following load bearing additives (G) and (H) were added as shown in Table 1 below.
Comparative oils 4-5 were prepared and a friction wear test was conducted. The results are also shown in Table 1.

(Load-bearing additive) (A): n-dodecylthio-N, N-diethyldithiocarbamate (B): dilaurylphosphite (C): Sb-dialkyldithiocarbamate (D): tricresylphosphate (E): Carbamate derivative mixture (F): Zn-sec-alkyldithiophosphate (G): Dibenzyl disulfide (H): Xanthene disulfide

[0060]

[Table 1]

As can be seen from the table, the shock absorber lubricant of the present invention suppresses wear and is an excellent shock absorber lubricant.

[0062]

Example 2 An α-olefin oligomer having a viscosity of 20 cSt at 25 ° C. and an ethylene-α-olefin oligomer having a viscosity of 500 cSt at 25 ° C. in a weight ratio of 2:
8% by weight based on this mixed oil
Diisooctyl adipate was added at a ratio of to prepare a base oil having a viscosity of 180 cSt at 25 ° C.

The above load-bearing additives or carbamates (A) to (F) were added to this base oil as shown in Table 2 below to prepare sample oils 21 to 30 and a friction wear test was conducted. The results are also shown in Table 2.

[0064]

Comparative Example 3 Organopolysiloxane oil having a viscosity of 180 cSt at 25 ° C. was used as a base oil, and the above load-bearing additives (D) to (F) were added as shown in Table 2 below, and Comparative oils 6 to 8 were added. Was prepared and a friction wear test was carried out. The results are also shown in Table 2.

[0065]

Comparative Example 4 Using the same base oil as in Example 2, the following load-bearing additives (I) and (J) were added as shown in Table 2 below,
Comparative oils 9-10 were prepared and a friction wear test was conducted. The results are also shown in Table 2.

(Load-bearing additive) (I): Benzotriazole (J): Indazole

[0067]

[Table 2]

As can be seen from the table, the shock absorber lubricant of the present invention suppresses wear and is an excellent shock absorber lubricant.

[0069]

Example 3 An α-olefin oligomer having a viscosity of 8 cSt at 25 ° C. and a viscosity of 100,000 c at 25 ° C.
An ethylene-α-olefin oligomer which is St is mixed in a weight ratio of 7: 3, and further 2 is added to this mixed oil.
Diisooctyl sebacate was added at a ratio of 5% by weight,
A base oil having a viscosity at 25 ° C. of 160 cSt was used.

The above load-bearing additives or carbamates (A) to (F) were added to this base oil as shown in Table 3 below to prepare sample oils 21 to 30 and a friction wear test was conducted. The results are also shown in Table 3.

[0071]

Comparative Example 5 Comparative oils 11 to 13 were prepared by using an organopolysiloxane oil having a viscosity of 160 cSt at 25 ° C. as a base oil and adding the load-bearing additives (D) to (F) as shown in Table 3 below. Was prepared and a friction wear test was carried out. The results are also shown in Table 3.

[0072]

Comparative Example 6 The same base oil as in Example 3 was used, and the load bearing additives (I) and (J) were added as shown in Table 3 below.
Comparative oils 14 to 15 were prepared and a friction wear test was conducted.
The results are also shown in Table 3.

[0073]

[Table 3]

As can be seen from the table, the shock absorber lubricant of the present invention is an excellent shock absorber lubricant that suppresses wear.

[0075]

Example 4 An α-olefin oligomer having a viscosity of 40 cSt at 25 ° C. and a viscosity of 100,000 at 25 ° C.
An ethylene-α-olefin oligomer which is cSt was mixed at a weight ratio of 8: 2, and diisodecyl adipate was added at a ratio of 20% by weight to the mixed oil,
The base oil had a viscosity at 25 ° C. of 350 cSt.

To this base oil, the load-bearing additives (D) to
(F) is added as shown in Table 4 below, and sample oils 31 to 3 are added.
3 was prepared and attached to a commercially available piston type shock absorber,
The vertical movement was repeated with an oblique load at a frequency of 100 Hz. After running for 500 hours, the shock absorber was disassembled and the condition of the piston was observed. In addition, the amount of iron in the shock absorber lubricating oil was measured. The results are also shown in Table 4.

[0077]

Comparative Example 7 A comparative oil 16 was prepared by using an organopolysiloxane oil having a viscosity of 350 cSt at 25 ° C. as a base oil and adding the above load-bearing additive (E) as shown in Table 4 below. 4 was tested in the same manner. The results are also shown in Table 4.
Shown in.

[0078]

Comparative Example 8 The same base oil as in Example 4 was used, the above load-bearing additive (G) was added as shown in Table 4 below, Comparative Oil 17 was prepared, and tested in the same manner as in Example 4. The results are also shown in Table 4.

[0079]

[Table 4]

As can be seen from the table, the shock absorber lubricant of the present invention suppresses wear and is an excellent shock absorber lubricant.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication C10M 105: 32 107: 02 135: 18) C10N 20:02 30:06 40:08 (72) Invention Person Taisei Ueda 1-3-1, Nishitsurugaoka, Oi-cho, Iruma-gun, Saitama Prefecture Tonen Corporation Research Institute

Claims (2)

[Claims] 1. A compound represented by the general formula (1): (In the formula, R, R ′, and R ″ are a hydrocarbon group having 1 to 12 carbon atoms or a halogenated hydrocarbon group, x, y, and p are integers, x is 0 to 30, y is 1 to 30, p is 1 to 20), and is a mixed oil of a plurality of polyolefins having a viscosity ratio at 25 ° C. different by at least 1: 5, and a polyolefin oil having a viscosity at 25 ° C. of 5 cSt to 5000 cSt. Base oil, load-bearing additive and /
Alternatively, a lubricating oil for shock absorbers, which is obtained by adding carbamates. 2. A compound represented by the general formula (1): (In the formula, R, R ′, and R ″ are a hydrocarbon group having 1 to 12 carbon atoms or a halogenated hydrocarbon group, x, y, and p are integers, x is 0 to 30, y is 1 to 30, p is 1 to 20) and a mixed oil of a plurality of polyolefins having a viscosity ratio at 25 ° C. different by at least 1: 5, wherein the mixed oil has a viscosity at 25 ° C. of 5 cSt to 5000 cSt, and A lubricant for a shock absorber, comprising an ester oil and / or an organopolysiloxane oil as a base oil, and a load-bearing additive and / or a carbamate.