JP2787715B2 - Lubricating oil composition - Google Patents

Description

The present invention relates to an internal combustion engine oil, an external combustion engine oil, a working oil, a refrigerating machine oil, a compressor oil, a gear oil, and a lubricating oil composition for various machines.

[Conventional technology]

Conventionally, internal combustion engine oil, external combustion engine oil, hydraulic oil, refrigerating machine oil,
Compressor oil, gear oil and lubricating oil compositions for various machines use mineral oil, silicone oil, olefin oligomer, organic acid ester, synthetic oil such as alkylbenzene as base oil, etc. It is manufactured by adding an index improver, an antiwear agent and the like. In some cases, several types of base oils are mixed and used, but the base oils having compatibility are used in a mixture.

However, although the addition of additives is useful in one aspect in improving the performance of lubricating oil compositions, viscosity index improvers, for example, show a decrease in viscosity due to shearing of the polymer during use, and also have a resistance to viscosity. There is a problem in that the cost increases due to the addition of the abrasive.

[Problems to be solved by the invention]

The present invention, although unexpected by dispersing a high viscosity oil in a low viscosity oil, viscosity index improving effect,
It has been found that abrasion resistance and shear stability can be improved, whereby the present invention can omit or reduce the addition of a viscosity index improver or an antiwear agent, and prevent a decrease in viscosity of used oil. Another object of the present invention is to provide a long-life lubricating oil composition.

[Means for solving the problem]

The lubricating oil composition of the present invention comprises a low-viscosity oil as a dispersion medium and a high-viscosity oil as a dispersoid substantially incompatible with the dispersion medium.

Further, a dispersant is added to the lubricant composition to stably disperse the high-viscosity oil in the low-viscosity oil.

As the low-viscosity oil, silicone oil, olefin oligomer, mineral oil, organic acid ester, phosphate ester, polyalkylene glycol, alkylbenzene and derivatives thereof can be used.

The kinematic viscosity of the low-viscosity oil as a dispersion medium is 1 mm at 100 ° C.
² / ^s~100mm was ² / s, particularly preferably a kinematic viscosity 3 mm ² / s
~30mm it may prefer to use low-viscosity oil which is ² / s.

First, as silicone oil (Where R is a group selected from the group consisting of a monovalent hydrocarbon group, a monovalent halogenated hydrocarbon group and a cyanoalkyl group, and n is 0 or an integer of 1 or more). .

The olefin oligomer that can be used in the present invention has 2 to 14 carbon atoms, preferably 4 to 14 carbon atoms.
It is obtained by copolymerization of any one kind of homopolymer or two or more kinds selected from olefin hydrocarbons having or not having 12 branches, and has an average molecular weight of 10
It is selected from 0 to about 2000, preferably 200 to about 1000 products, especially those from which unsaturated bonds have been removed by hydrogenation. Preferred olefin oligomers include:
For example, polybutene, α-olefin oligomer, ethylene / α-olefin oligomer, and the like. As the polybutene, for example, those obtained mainly by isobutene and obtained by copolymerizing a monomer mixture of butene-1 and butene-2 are preferable. As the α-olefin oligomer, thermal decomposition of hydrocarbons or trimerization of lower olefins to 6
An α-olefin mixture having 6 to 12 carbon atoms obtained by quantification, for example, 25% to 50% by weight of hexene-1, 30% to 40% by weight of octene-1 and 25% by weight of decene-1
A copolymer obtained by copolymerizing a mixture of about 40% by weight can be used. Oligomers obtained from a single monomer such as decene are also suitable. Further, as the ethylene / α-olefin oligomer, 40% to 90% by weight of ethylene and 10% to 60% by weight of α-olefin, for example, propylene.
What mixed and polymerized the monomer of the ratio of weight% can be used.

These olefin oligomers can be produced using a Friedel-craft catalyst such as aluminum chloride and boron fluoride, an oxide catalyst such as Ziegler catalyst and chromium oxide, and the like. The hydrogenation of the olefin oligomer can be carried out by removing the catalyst from the reaction product and then contacting it with a hydrogenation catalyst such as nickel-molybdenum / alumina under heating and pressure.

Alkyl benzene can also be included as one of the low viscosity oils of the present invention. This is mainly of the alkylbenzene type, in which aromatic hydrocarbons such as benzene and toluene are alkylated by a Friedel-Crafts reaction or the like to produce mainly dialkylated aromatic hydrocarbons that are by-produced when producing detergent raw materials. Oil containing. As the alkyl group, straight-chain or branched ones belong to this.

The mineral oil is a hydrocarbon oil fraction having a lubricating viscosity.For example, a raffinate obtained by extracting a vacuum distilled distillate with a solvent such as phenol, furfural or N-methylpyrrolidone is used as a solvent in a solvent such as propane or methyl ethyl ketone. After the solvent dewaxing, the hydrocarbon distillate obtained after further subjecting it to hydrorefining to improve the hue and remove unstable substances as needed, or this hydrocarbon distillate and solvent Mixtures with residual oils that have been subjected to extraction, solvent dewaxing and solvent de-historing can be used. In some cases, catalytic dewaxing is performed instead of solvent dewaxing. These refined mineral oils may be paraffinic, naphthenic, etc. alone or may be a mixture of these hydrocarbon oils.

Next, as one of the organic acid esters, there is one obtained by reacting an aliphatic dibasic acid having 4 to 14 carbon atoms with an aliphatic alcohol having 4 to 14 carbon atoms.

As dibasic acids that can be used for the synthesis,
For example, succinic acid, glutaric acid, adipic acid, piperic acid, suberic acid, azelaic acid, sebacic acid, undecandioic acid, dodecandioic acid, brassic acid, and tetradecandioic acid, preferably adipic acid, azelaic acid, sebacic acid, dodecane Diacids and the like can be mentioned, and among these, adipic acid and sebacic acid are particularly preferable.

Examples of the aliphatic alcohol include n-butanol,
Isobutanol, n-amyl alcohol, isoamyl alcohol, n-hexanol, 2-ethylbutanol,
Cyclohexanol, n-heptanol, isoheptanol, methylcyclohexanol, n-octanol,
Dimethylhexanol, 2-ethylhexanol, 2,
4,4-trimethylpentanol, isooctanol,
Examples thereof include 3,5,5-trimethylhexanol, isononanol, isodecanol, isoundecanol, 2-butyloctanol, tridecanol, and isotetradecanol. Among them, 2-ethylhexanol, isodecanol and tridecanol are particularly preferable.

The synthesis of a diester from a dibasic acid and an alcohol,
It can be carried out by a conventional method, for example, a method of performing dehydration condensation under an acidic catalyst. The diester thus obtained is, for example, di- (1-ethylpropyl) adipate,
Di- (3-methylbutyl) adipate, di- (1,3-dimethylbutyl) adipate, di- (2-ethylbutyl)
Adipate, di (2-ethylhexyl) adipate,
Di- (isooctyl) adipate, di- (isononyl)
Adipate, di- (3,5,5 trimethylhexyl) adipate, di- (isodecyl) adipate, di- (undecyl) adipate, di- (tridecyl) adipate, di-
(Isotetradecyl) adipate, di- (2,2,4-
Trimethylpentyl) adipate, di- [mixed (2-ethylhexyl, isononyl)] adipate, di- (1-
Ethylpropyl) azelate, di- (2-ethylbutyl) azelate, di- (2-ethylhexyl) azelate, di- (isooctyl) azelate, di- (isononyl) azelate, di- (3,5,5 trimethylhexyl) azelate, Di- (isodecyl) azelate, di- (tridecyl) azelate, di- [mixed (2-ethylhexyl, isononyl)] azelate, di- [mixed (2-ethylhexyl, decyl)] azelate, di- [mixed (2-
Ethylhexyl, isodecyl)] azate, di- [mixed (2-ethylhexyl, 2-propylheptyl)] azelate, di- [mixed (2-ethylhexyl, decyl)] azelate, di- (n-butyl) sebacate, di- ( Isobutyl) sebacate, di- (1-ethylpropyl) sebacate, di- (3-methylbutyl) sebacate, di- (1,3-dimethylbutyl) sebacate, di-
(2-ethylbutyl) sebacate, di- (2-ethylhexyl) sebacate, di- [2- (2'-ethylbutoxy) ethyl] sebacate, di- (2,2,4-trimethylpentyl) sebacate, di- (isononyl) ) Sebacate,
Di- (3,5,5 trimethylhexyl) sebacate, di-
(Isodecyl) sebacate, di- (isoundecyl) sebacate, di- (tridecyl) sebacate, di- (isotetradecyl) sebacate, di- [mixed (2-ethylhexyl, isononyl)] sebacate, di- (2-ethylhexyl) glutarate , Di- (isoundecyl) glutarate and di- (isotetradecyl) glutarate.

Another type of organic acid ester is neopentyl polyol ester.

Neopentyl polyol esters are made by the synthesis of neopentyl polyols having 5 to 9 carbon atoms and organic acids having 4 to 18 carbon atoms. In the present invention, neopentyl polyol is a polyhydric alcohol having a neopentyl group, for example, 2,2-dimethylpropane-1,3-diol (that is, neopentyl glycol), 2-ethyl-2-
Butyl-propane-1,3-diol, 2,2-diethylpropane-1,3-diol, 2,2-dibutylpropane-1,3-
Diol, 2-methyl-2-propylpropane-1,3-
Diol, 2-ethyl-2-butylpropane-1,3-diol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, preferably neopentyl glycol, 2-methyl-2-propylpropane-1,3 -Diols, trimethylolpropane, pentaerythritol, particularly preferred are neopentyl glycol, trimethylolpropane, pentaerythritol. Organic acids include, for example, n-butanoic acid, isobutanoic acid, n-pentanoic acid, isopentanoic acid, n-hexanoic acid, 2-ethylbutanoic acid, cyclohexanoic acid, n-heptanoic acid, isoheptanoic acid, methylcyclohexanoic acid, n-octane Acid, dimethylhexanoic acid, 2-ethylhexanoic acid, 2,4,4-trimethylpentanoic acid, isooctanoic acid, 3,5,5-trimethylhexanoic acid, n-nonanoic acid, isononanoic acid, isodecanoic acid, isoundecanoic acid, 2-butyloctanoic acid, tridecanoic acid,
Tetradecanoic acid, hexadecanoic acid and octadecanoic acid, preferably heptanoic acid, n-octanoic acid and 2-ethylhexanoic acid.

The synthesis of neopentyl polyol ester from an organic acid and neopentyl polyol can be carried out by a conventional method, for example, a method of dehydration-condensation under an acidic catalyst.

For example, neopentyl polyol esters (hereinafter, neopentyl is NPG, trimethylolpropane is TM
P and pentaerythritol are abbreviated as PE. ), NGP di- (heptanoate), NPG di- (2-ethylbutyrate), NPG di- (cyclohexanoate), NPG di- (heptanoate), NPG di- (isoheptanoate) NPG di- (octylate), NPG di- (2-ethylhexanoate), NPG di- (isooctanoate), NPG di- (isononylate), NPG di- (isodecanoate), NPG .Di- ｛mixed (hexanoate,
Heptanoate)｝, NPG-di-mixed (hexanoate, octanoate)｝, NPG-di-mixed (hexanoate, nonylate)｝, NPG-di-mixed (heptanoate, octanoate)｝, NPG-di-mixed ( Heptanoate, nonylate), NPG di-mixed (heptanoate, isooctanoate), NPG di-mixed (heptanoate, isononylate), NPG di-
｛(Mixed (isooctanoate, isononylate)｝,
NPG di-mixed (butanoate, tridecanoate), NPG di-mixed (butanoate, tetradecanoate), NPG di-mixed (nobdate, hexadecanoate), NPG di- Mixed (butanoate, octadecanoate)｝, NPG di- {mixed (hexanoate, isooctanoate, isononylate)}, NPG di- {mixed (hexanoate, isooctanoate, isodecanoate)}, NPG di − {Mixing (heptanoate, isooctanoate, isononylate)}, NPG di-mixing (heptanoate, isooctanoate, isodecanoate), NPG di-mixing (octanoate, isononylate, isodecanoate), TMP Tri- (pentanoate), TMP ・ Tri-
(Hexanoate), TMP tri- (heptanoate), TMP tri- (octanoate), TMP tri-
(Nonylate), TMP tri (isopentanoate), TMP tri (2-ethylbutyrate), TMP tri (isopentanoate), TMP tri (isooctanoate), TMP・ Tri- (2-ethylhexanoate), TMP ・ Tri- (isononylate), TMP ・ Tri-
(Isodecanoate), TMP • tri- [mixture (butyrate, octadecanoate)], TMP • tri- [mixture (hexanoate, hexadecanoate)], TMP • tri-
[Mixing (heptanoate, tridecanoate)], TMP
・ Tri- [mixed (octanoate, decanoate)],
TMP • tri- [mixed (octanoate, nonylate)], TMP • tri- [mixed (butyrate, heptanoate, octadecanoate)], TMP • tri- [mixed (pentanoate, heptanoate, tridecanoate)], TMP • tri- [Mixed (hexanoate, heptanoate, octanoate)] Also, PE tetra (pentanoate), PE tetra (hexanoate), PE tetra (isopentanoate), PE tetra (2-ethylbutyrate), PE Tetra (isoheptanoate), PE
・ Tetra (isooctanoate), PE ・ Tetra (2-ethylhexanoate), PE ・ Tetra (isononylate)
And an ester of PE with a mixture of a linear or branched carboxylic acid having 4 to 8 carbon atoms.

In addition, NPG, neopentyl polyol other than TMP and PE,
That is, examples thereof include polyol esters of 2-methyl-2-propylpropane-1,3-diol, 2,2-diethylpropanediol, trimethylolethane, and trimethylolhexane with the above-mentioned organic acids alone or in combination.

As the phosphoric ester, tricresyl phosphate, tolyl phosphate, tri (2-ethylhexyl) phosphate, erkyphenyl phosphate, alkylphenylphenyl phosphate, and the like can be used.

The polyalkylene glycol is a ring-opening polymer or a ring-opening copolymer of a linear or branched alkylene oxide having 2 to 5, preferably 2 to 3 carbon atoms in the alkylene group. As the alkylene oxide, ethylene oxide, propylene oxide, butylene oxide, or a mixture thereof, preferably propylene oxide, preferably polyethylene glycol, polypropylene glycol can be mentioned, those having a molecular weight range of 100 to 2000, preferably 200 ~ 1000 things.

Next, the dispersoid dispersed in the low-viscosity oil will be described.

As the highly viscous oil which is a dispersoid, it is preferable to use silicone oil, fluorinated oil, olefin oligomer, short-chain polymethacrylate, polyalkylene glycol, or the like.

The kinematic viscosity of these highly viscous oils is 10 mm ² / s at 100 ° C.
~100,000mm a ² / s, particularly preferably a kinematic viscosity 30 mm ² /
s~30,000mm good to use a high viscosity oil is ² / s.

As silicone oil Wherein R is a group selected from the group consisting of a monovalent hydrocarbon group, a monovalent halogenated hydrocarbon group and a cyanoalkyl group, and n is 0 or an integer of 1 or more. It has an average molecular weight in the range of 500 to 200,000.

As the fluorinated oil, polychlorotrifluoroethylene represented by the following formula _{- (CF 2 -CFCl) n -} ( wherein, n 4 to 18) (kinematic viscosity 10 mm ² on a molecular weight 500～2,000,100 ° C. / s ~ 1,000m
m ² / s) formula, Molecular weight of 2,000 to 10,000, kinematic viscosity at 100 ° C of 10 mm
² / s to 50 mm ² / s or the like can be used.

As an α-olefin oligomer, a carbon number of 35 to 3,50
0, preferably having a branch in the range of 50 to 700, or obtained by copolymerization of any one kind of homopolymer or two or more kinds selected from olefinic hydrocarbons having no average molecular weight of 500 to 50,000, preferably 700 to 10,000
Which is preferably a product from which unsaturated bonds have been removed by hydrogenation. Preferred olefin oligomers include, for example, polybutene, α-olefin oligomer, ethylene / α-olefin oligomer, and the like. Kinematic viscosity at 100 ° C. can be used those 10mm ² / s~10,000mm ² / s.

As polymethacrylate, the formula (Wherein, R C ₁ ~C _18, n is an integer of five or more) can be used as the kinematic viscosity of 50mm ² / s~100,000mm ² / s at 100 ° C. represented by.

The polyalkylalkylene glycol is a ring-opening polymer or a ring-opening copolymer of a linear or branched alkylene oxide having 2 to 5, preferably 2 to 3 carbon atoms in the alkylene group. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide,
Or a mixture thereof, preferably propylene oxide, preferably polyethylene glycol or polypropylene glycol having a molecular weight of 500 to 20,000.

In the lubricating oil composition of the present invention, it is necessary that the low-viscosity oil that is the dispersion medium and the high-viscosity oil that is the dispersoid do not have compatibility. It is necessary that the combination has no compatibility.

First, when using silicone oil as a low-viscosity oil,
The above dispersoids are insoluble except for the high viscosity silicone oil, and can be used as the lubricating oil composition of the present invention. Particularly preferred is a case where polyethylene glycol or polypropylene glycol is used as the dispersoid.

When an olefin oligomer is used as a dispersion medium, silicone oil, short-chain polymethacrylate, polyethylene glycol, or polypropylene glycol may be used as a dispersoid having no compatibility.

When mineral oil is used as the dispersion medium, silicone oil, short-chain polymethacrylate, polyethylene glycol, or polypropylene glycol may be used as the dispersoid.

Further, when an organic acid ester is used as a dispersion medium, silicone oil is preferably used as a dispersoid.

When a phosphate is used as a dispersion medium, silicone oil and an olefin oligomer are preferably used as a dispersoid.

Further, when polyethylene glycol or polypropylene glycol is used as the dispersion medium, silicone oil or olefin oligomer may be used as the dispersoid.

The ratio of the kinematic viscosity of the low-viscosity oil to the high-viscosity oil at 100 ° C. in the present invention is 2 to 2 when the kinematic viscosity of the low-viscosity oil is 1.
The range is preferably 100,000, particularly preferably 5 to 3,000. The lubricating oil composition of the present invention is constituted by appropriately selecting such a kinematic viscosity ratio from the above-described dispersion medium and dispersoid. When the kinematic viscosity ratio is less than 2, the dispersion medium and the dispersion medium are dispersed. The viscosity of the oil is close, the viscosity of the high viscosity oil is too low and the characteristics are not clear compared with the dispersion medium alone, 100,000
Exceeding the range is undesirable because the oil becomes a solid state. The dispersoid may be used in a proportion of 0.5% by weight to 50% by weight, preferably 1% by weight to 30% by weight, based on the dispersion medium.

In order to disperse the dispersoid in the dispersion medium, the two liquid components may be mixed using a mixer, a roll mill, or the like. When the lubricating oil composition of the present invention is subjected to the action of flow, stirring, or the like during use, the dispersion medium and the dispersoid may be separated in the lubricating oil composition because they are dispersed during use. It is preferable to add a dispersant to the lubricating oil composition of the present invention and uniformly disperse it.

The dispersant is not particularly limited, a low molecular dispersant,
It may be appropriately selected from polymer dispersants. Specific low-molecular dispersants include aliphatic, aromatic carboxylic acid metal salts, or esters thereof, sulfate ester metal salts, sulfonate metal salts, phosphate ester metal salts,
Nonionic surfactants such as quaternary ammonium salts, polyoxyethylenes, polyhydric alcohols, and alkylolamides, and lipophilic polar substances such as polyesters, polyamides, polyamines and the like as polymer dispersants Derivatives, alkenyl succinimides, alkenyl benzylamines, petroleum resins (indene maron resins), various rosins, derivatives thereof and the like can be used.
The dispersant may be used in an amount of 0.05% by weight to 20% by weight, preferably 0.1% by weight to 10% by weight.

The lubricating oil composition of the present invention may contain a metal detergent (eg, magnesium sulfonate), an ashless detergent / dispersant (eg, alkenyl succinimide), and an antioxidant (eg, phenol, zinc thiophosphate) as necessary. At least one additive such as an antifoaming agent (silicone-based or the like) can be added. In particular, 0.1% to 5.0% by weight of metal detergent, ashless detergent and dispersant
0.1% to 10.0% by weight, antioxidant 0.1% to 1.5%
% By weight, and the content of the antifoaming agent is preferably 0.001% by weight to 0.01% by weight.

[Action]

The lubricating oil composition of the present invention is prepared by dispersing a high-viscosity oil in a low-viscosity oil. Liquid high-viscosity oil swells at high temperatures and the volume fraction in lubricating oil increases, resulting in an increase in viscosity,
It is thought to improve the viscosity index (viscosity index improvement), and the high-viscosity particles in the friction plane support the load, retain the oil film, prevent friction between metals, and reduce friction and prevent wear. Can be
(Abrasion resistance improving property), as compared with a viscosity index improver which is usually used, it has been found that molecules are less likely to be cut by shearing and there is no decrease in viscosity (shear stability). is there.

Therefore, the lubricating oil composition of the present invention is particularly suitable when used as an internal combustion engine oil, an external combustion engine oil, a hydraulic oil, a refrigerating machine oil, a compressor oil, a gear oil and a lubricating oil composition for various machines. It can be done as an object.

Example 1 dispersion medium; mineral oil; 100 Neutral, a viscosity 4.3 mm ² / s (100 ° C.) dispersoid; polypropylene glycol (trade name LB-3000, Sanyo Kasei Co., Ltd., viscosity 90 mm ² / s
(100 ° C.) Dispersing agent: Alkenyl succinic ester (trade name: Lubrizol 926, manufactured by Lubrizol Co., Ltd.) was used, and the dispersoid was added to mineral oil in 1.0% by weight, 5.0% by weight, and 7.% by weight.
5% by weight, 10.0% by weight
The composition containing the composition by weight was mixed by a mixer to obtain a lubricating oil composition of the present invention.

The kinematic viscosity and the viscosity index of each lubricating oil composition of the present invention were measured according to JISK2283.

The result is shown as line A in FIG. Note that A
The numbers on the line indicate the content (% by weight) of the dispersoid.

For comparison, the same mineral oil as above was added with 7.0% by weight of a polymethacrylate (trade name; PLX-1019, manufactured by Nippon Acrylic Co., Ltd.) as a viscosity index improver, and the kinematic viscosity and viscosity index were measured. The same FIG. 1 shows by the B line.

Similarly, in the case of mineral oil having various kinematic viscosities obtained by mixing briquette with 100 neutral mineral oil, the viscosity indices were respectively measured, and the results are shown as a line C in FIG.

According to this, it is understood that the lubricating oil composition of the present invention has a higher viscosity index improving effect as compared with those in which a viscosity index improver is added and those in which mineral oil is used alone.

[Example 2] (Abrasion resistance test) Mineral oil 100 neutral contained 10% by weight of the polypropylene glycol used in Example 2 as a dispersoid, and 3% by weight of the succinate used in Example 1 as a dispersant. The mixture was dispersed by a mixer to prepare a lubricating oil composition of the present invention.

As a comparison of the present invention, polymethacrylate (; PLX-1019, manufactured by Nippon Acrylic Co., Ltd.) was added to mineral oil (100 neutral + bright stock) and mineral oil 100 neutral.
The gear oil additive oil contained in a weight percentage was used. Shows the viscosity of 6.3mm ² /s~6.7mm ² / s at even 100 ° C. Any oil. A comparative test for abrasion resistance was carried out using a shell four-ball abrasion resistance tester in accordance with ASTEM D4172, and the test conditions were set to 60.
The measurement was performed at 0 rpm, a load of 15 kg, a temperature of 60 ° C., and a time of 30 minutes, and the relationship between the load (kg) and the wear scar radius (mm) was determined. The result is shown by the broken line in FIG.

In addition, the circle mark on the broken line indicates the measurement result in the case of the lubricating oil composition of the present invention, and the square mark indicates the measurement result in the case of the oil added with the viscosity index improver for gear oil. According to this, it is understood that the lubricating oil composition of the present invention is superior in abrasion resistance as compared with the viscosity index improver oil for gear oil.

In addition, the lubricating oil composition of the present invention, the oil added with the viscosity index improver for gear oil, and the mineral oil alone each contained 0.5% by weight of zinc dialkyldithiophosphate as an antiwear agent, and abrasion resistance test was performed in the same manner as described above. Was carried out. This result is shown by a solid line in FIG.

The solid circles on the solid line indicate the case of the lubricating oil composition of the present invention, the solid squares indicate the case where the viscosity index improver for gear oil is added to the mineral oil, and the solid circle indicates the case where the mineral oil is used alone.

According to this, it is understood that the lubricating oil composition of the present invention is superior in abrasion resistance as compared with the viscosity index improver oil for gear oil. The addition of an antiwear agent can improve the abrasion resistance, but it can be seen that the effect is particularly remarkable as compared with oils added with a viscosity index improver for gear oils and mineral oils.

[Example 3] (Shear stability test) The lubricating oil composition of the present invention prepared in Example 2, oil containing a viscosity index improver for gear oil (containing 7% by weight of polymethacrylate), improvement of viscosity index for engine oil Oils (containing 5% by weight of polymethacrylate) and mineral oil (100 neutral + bright stock)
But in which at 0 ℃ tailored to the viscosity of 6.3mm ² /s~6.7mm ² / s, for each case alone, the lubricating oil shear stability test sample irradiation time to and 30, Petroleum Institute standard JPI −6S
-29-88. FIG. 3 shows the relationship between the shearing time (minutes) and the viscosity change rate, and FIG. 4 shows the relationship between the shearing time (minutes) and the viscosity index.

In the figure, the case of the lubricating oil composition of the present invention is indicated by a circle, the case of a viscosity index improver-added oil for gear oil is indicated by a triangle, the case of a viscosity index improver-added oil for engine oil is indicated by □, and mineral oil alone is used. ● the case
Shown by a mark.

This shows that the lubricating oil composition of the present invention exhibits excellent shear stability as compared with the viscosity index improver-added oil.

〔The invention's effect〕

The lubricating oil composition of the present invention comprises a low-viscosity oil which is a dispersion medium, a high-viscosity oil which is a dispersoid having substantially no compatibility with the dispersion medium, and a dispersant which is optionally contained. It has a high viscosity index improving effect and is excellent in wear resistance, and furthermore shows excellent shear stability, so that especially internal combustion engine oil, external combustion engine oil, hydraulic oil, refrigerating machine oil,
It is excellent as a compressor oil, a gear oil and a lubricating oil composition for various machines.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the improvement of the viscosity index of the lubricating oil composition of the present invention. FIG. 2 is a diagram for explaining the wear resistance of the lubricating oil composition of the present invention. FIG. 4 is a diagram for explaining the shear stability of the lubricating oil composition of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10M 129: 95) C10N 30:02 30:04 30:06 40:04 40:08 40:25 40:30 (56) References JP-A-63-210198 (JP, A) JP-A-61-264097 (JP, A) JP-A-59-129294 (JP, A) JP-A-56-76495 (JP, A) (58) (Int.Cl. ⁶ , DB name) C10M 171 / 00,169 / 04 C10N 30:02-30:06 C10N 40: 04,40: 08 C10N 40: 25,40: 30

Claims (2)

(57) [Claims] A kinematic viscosity at 100 ° C. as a dispersion medium of 1 to 3
0 mm ² / s low viscosity oil (A) and a kinematic viscosity at 100 ° C. of 30 to 10 which is a dispersoid substantially incompatible with the dispersion medium.
A lubricating oil composition comprising a high-viscosity oil (B) having a viscosity of 100,000 mm ^{2 and} a high-viscosity oil (B) having a low viscosity at 100 ° C. If the kinematic viscosity of the viscous oil is 1, 2 to 100,
000, and b) a viscosity index improving effect, wherein the high viscosity oil (B) is uniformly dispersed in the low viscosity oil (A).
A lubricating oil composition having excellent wear resistance and shear stability. 2. The lubricating oil composition according to claim 1, further comprising a dispersant (C).