JPH0388894A - Automotive lubricating oil composition - Google Patents

Abstract

PURPOSE:To provide the title composition excellent in viscosity index-improving effect, wear resistance and shear stability, thus to be used as engine oil, gear oil, chassis oil, etc., comprising a low-viscosity oil as dispersion medium and, as disperse phase, a high-viscosity oil incompatible with the low-viscosity oil. CONSTITUTION:The objective composition comprising (A) a low-viscosity oil as dispersion medium, consisting of silicone oil, olefin oligomer, mineral oil, organic acid ester, phosphoric ester, polyalkylene glycol, alkylbenzene or derivative thereof (esp. pref. with a kinematic viscosity of 3-30mm<2>/s at 100 deg.C) and (B) a high-viscosity oil as disperse phase, incompatible with the component A. such as silicone oil, fluorinated oil, olefin oligomer, short chain polymethacrylate or polyalkylene glycol (esp. pref. with a kinematic viscosity of 30-30000mm<2>/s at 100 deg.C).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides an automotive lubricating oil that is used as engine oil, gear oil, chassis oil, etc. and has excellent viscosity index improvement effect, wear resistance properties, and shear stability. Regarding the composition.

[Conventional technology]

Conventionally, automobile engine oils such as gasoline engine oil and diesel engine oil, as well as lugya oil in differential oil,
Lubricant oils such as transmission oil such as transmission gear oil, power steering oil, automatic transmission oil, chassis oil such as thick absorber oil, etc. Mineral oil, silicone oil, olefin oligomer, organic acid ester, alkylbenzene These synthetic oils are used as base oils and are manufactured by adding viscosity index improvers, anti-wear agents, etc. in order to improve their physical properties. Although several types of base oils may be used as a mixture, base oils that are compatible with each other are used as a mixture.

However, although the addition of additives is useful in improving the performance of lubricants and animals, for example, viscosity index improvers can reduce viscosity due to shearing of the polymer during use, and also improve wear resistance. There is a problem in that the addition of such agents increases costs.

[Problem to be solved by the invention]

The present invention has unexpectedly discovered that by dispersing a high viscosity oil in a low viscosity oil, the viscosity index improving effect, abrasion resistance, and shear stability can be improved. As a result, it is an object of the present invention to provide a lubricating oil composition that can omit or reduce the addition of a viscosity index improver or an anti-wear agent, prevents a decrease in the viscosity of the oil used, and has a long life.

[Means to solve the problem]

The lubricating oil composition of the present invention is characterized by comprising a low-viscosity oil as a dispersion medium and a high-viscosity oil as a dispersoid that is substantially incompatible with the dispersion medium.

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

As the low viscosity oil, silicone oil, olefin oligomer, mineral oil, organic acid ester, phosphoric acid ester, polyalkylene glycol, alkylbenzene and its 811 derivatives, etc. can be used.

The kinematic viscosity of the low viscosity oil used as the dispersion medium is 1 at 100°C.
It is advisable to use a low viscosity oil having a kinematic viscosity of tats''/s to 100 wm''/s, particularly preferably a kinematic viscosity of 3 +ms'/s to 30 vbm''/s.

First, as a silicone oil (hereinafter referred to as a blank) (herein, R is a group selected from the group consisting of a monovalent hydrocarbon group, a monovalent halogenated hydrocarbon group, and a sia and noalkyl group, and n is 0 or 1 (integer greater than or equal to).

In addition, the olefin oligomer that can be used in the present invention has 2 to 14 carbon atoms, preferably 4 to 14 carbon atoms.
Any II homopolymer selected from olefinic hydrocarbons with or without branching in the range of 12 or 2
Preferred olefins are those obtained by copolymerization of more than one species, and are selected from products with an average molecular weight of 100 to about 2000, preferably 200 to about 1000, and those with unsaturated bonds removed by hydrogenation are particularly preferred. Examples of the oligomer include polybutene, α-olefin oligomer, and ethylene/α-olefin oligomer. Preferably, the polybutene is one obtained by copolymerizing a monomer mixture of butene-1 and butene-2, with isobutene as the main component. Carbon number 6-12 obtained by 3fit-hexamerization of olefin
An α-olefin mixture of, for example, a mixture of 25% to 50% by weight of hexene-1, 30% to 40% by weight of octene-1, and 25% to 40% by weight of decene-1 is copolymerized. can be used. Also suitable are oligomers obtained from single monomers such as decene. Further, as the ethylene/α-olefin oligomer, use may be made by mixing and polymerizing monomers containing 40% to 90% by weight of ethylene and 10% to 60% by weight of α-olefin, such as propylene. I can do it.

These olefin oligomers include aluminum chloride,
It can be produced using a Friedelta-lat type catalyst such as boron fluoride, a Ziegler catalyst, and an oxide catalyst such as chromium oxide. Hydrogenation of the olefin oligomer can also be carried out by removing the catalyst from the reaction product and then bringing it into contact with a hydrogenation catalyst such as nickel-molybdenum/alumina under heat and pressure.

Alkylbenzenes can also be included as one of the low viscosity oils of the present invention. This is mainly of the alkylbenzene type, and is mainly dialkylated aromatic hydrocarbons, which are produced as by-products when aromatic hydrocarbons such as benzene and toluene are alkylated by the Friedel-Crach reaction to produce raw materials for detergents. Contains oil. The alkyl group includes either a straight chain or a branched alkyl group.

Mineral oils are hydrocarbon oil fractions with lubricating viscosity, such as raffinate obtained by extracting vacuum distillation distillate oil with a solvent such as phenol, furfural, or N-methylpyrrolidone. Hydrocarbon distillate oil obtained after solvent deasphalting treatment and, if necessary, further hydrorefining to improve hue and remove unstable substances, or this hydrocarbon distillate oil and solvent. Mixtures with residual oils from extraction, solvent dewaxing and solvent deasphalting processes can be used. Further, catalytic dewaxing treatment may be performed instead of solvent dewaxing treatment. These refined mineral oils are composed of paraffinic, naphthenic, etc.
Alternatively, it may be a mixed hydrocarbon oil.

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.

Dibasic acids that can be used for its synthesis include, for example, succinic acid, glutaric acid, adipic acid, piperic acid,
speric acid, azelaic acid, sebacic acid, undecanol, dodecanoic acid, brassylic acid, and tetradecanoic acid, preferably adipic acid, azelaic acid, sebacic acid,
Among these, adipic acid and sebacic acid are particularly preferred.

Examples of the aliphatic alcohol include n-butanol, isobutanol, n-amyl alcohol, isoamyl alcohol, n-hexanol, 2-ethylbutanol, cyclohexanol, n-heptatool, isoheptatool, methylcyclohexanol, n-octa Tool, dimethylhexanol, 2-ethylhexanol, 2.4
．． 4-trimethylpentanol, isooctatotool, 3
．． 5.5-trimethylhexanol, isononanol,
Examples include isodecanol, isoundecanol, 2-butyl octatool, tridecanol and isotetradecanol, but in particular 2-ethylhexanol,
Isodecanol and tridecanol are preferred.

A diester can be synthesized from a dibasic acid and an alcohol by a conventional method, for example, a dehydration condensation method under an acidic catalyst. The diesters obtained in this way are, for example, di(l-ethylpropyl)adipate, di(3-methylbutyl)adipate, di(1,3-dimethylbutyl)adipate, di(2-ethylbutyl)
adipate), ')-(2-ethylhexyl)adipate, di(isooctyl)adipate, di(isononyl)adipate, di(3,5,5)limethylhexyl)
Adipate, Di(isodecyl)adipate, Di(undecyl)adipate, Di(tridecyl)adipate, Di(isotetradecyl)adipate, Di(2,2
, 4-trimethylpentyl〉adipate, G [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) Limethylhexyl) azelate, di(isodecyl) azelate, di(tridecyl) azelate, di[mixed (2-ethylhexyl, isononyl)] azelate, di[mixed (2-ethylhexyl, isononyl)]
-ethylhexyl, decyl)] azelate, di[mixed (2-ethylhexyl, isodecyl)] azelate, di[mixed (2-ethylhexyl, 2-propylhexyl)] azelate, di[mixed (2-ethylhexyl, decyl)] azelate , di(n-butyl) sebacate,
Di(isobutyl) sebacate, di(l-ethylpropyl) sebacate, di(3-methylbutyl) sebacate, di(l,3-dimethylbutyl) sebacate, di(2-ethylbutyl) sebacate, di(2-ethylhexyl) sebacate, Di(2-(2'-ethylbutoxy)ethylbutanol, di(2,2,4-)limethylpentyl)sebacate, di(isononyl>sebacate, di(3,5゜5trimethylhexyl)sebacate,
Di(isodecyl) sebacate, di(isooundecyl) sebacate, di(tridecyl) sebacate, di(isotetradecyl> sebacate, di[mixed (2-ethylhexyl, isononyl)] sebacate, di(2-ethylhexyl) glutarate, di(isooundecyl) ) glutarate and di(isotetradecyl) glutarate.

Another type of organic acid ester is neopentyl polyol ester.

Neopentyl polyol ester is produced by combining a neopentyl polyol having 5 to 9 carbon atoms and an organic acid 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 (i.e. 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, 2methyl-2-propylpropane-1,3 -diol, trimethylolpropane, pentaerythritol, and particularly preferred are neopentyl glycol, trimethylolpropane, and pentaerythritol.

Further, organic acids include, for example, n-butanoic acid, isobutanoic acid, n-
Pentanoic acid, isopentanoic acid, n-hexanoic acid, 2-ethylbutanoic acid, cyclohexanoic acid, n-hebutanoic acid, isohebanoic acid, methylcyclohexanoic acid, n-octanoic acid, dimethylhexanoic acid, 2-ethylhexanoic acid, 2゜4.4-) Limethylpencunic 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 hebutanoic acid, n -Octanoic acid, 2-ethylhexanoic acid.

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

For example, as neopentyl polyol ester (hereinafter, neopentyl is NPC, trimethylolpropane is T
MP and pentaerythritol are collectively referred to as PE. )
, NPC G (Heptanony)), NPC G (
2-Ethylbutyrate>, NPC・G (cyclohexanoate), NPC・G (heptanoate), N
PC・G (isoheptanoate), NPC・G (octylate), NPC・G (2-ethylhexanony)), NPC・G (isooctanoate), NPC
・G (isononylate), NPC・G (isodecaneate), NPC・G (mixed (hexanoate, heptanony))), NPC・G (mixed (hexanoate, octanoate)), NPC・G (mixed (hexanoate, nonylate)), NPC G (mixed)
Heptanoate.

octanoate)), NPG-G (mixed (heptanoate, nonylate)), NPC-G (mixed (heptanoate, iso-octanoate)), NPC-G (mixed (heptanoate, isononylate)'t, NPC
・G (mixture (isooctanoate, isononylate))
, NPC・G (mixed (butanoate, tridecanoic acid)) , NPC・G (mixed (butanoate, tetrazocaate)) , NPC・G (mixed (
Butanoate.

hexadecanoate)), NPG-G (mixed (butanoate, octadecanoate)), NPG-G (mixed (hexanoate, isooctanoate, isononylate)), NPC-G (mixed (hexanoate, isooctanoate, isodecanoate))), NPC・G (mixed (heptanoate, isooctanoate, isononylate))), NPC・G (mixed (heptanoate, isooctanoate, isodecanate)), NPC
・G (mixture (octanoate, isononylate, isodecanoate)), TMP・tree (pentanoate) < TMP・tree (hexanony)), TMP・
Tory (Heptanoate), TMP Tory (Octanony)), TMP Tory (Nonyre)), TMP
・Tree (isopentanony)), TMP・Tree <2
-ethylbutyrate), TMP-tri(isopentanony)), TMP-tri(isooctanoate)
, TMP tri(2-ethylhexanoate), TM
P-tree (isononylate), TMP-tree (isodecanoate), TMP-tree [mixed butyrate, octadecanoate], TMP-tree [mixed (
hexanoate, hexadecanoate)), TMP・
Tory [mixed (heptanoate, tridecanoate)]
, TMP-tree [mixture (octanoate, decanoate)], TMP-tree [mixture (octanoate, nonylate)], TMP-tree [mixture (butyrate, heptanoate, octadecanoate)], TMP-tree [mixture (pentanoate, heptanoate, tridecanoate)), TMP/Tree [mixture (hexanoate, heptanoate, octanoate)], and PE
・Tetra (pentanoate), PR tetra (hexanoate), PR tetra (isopentanony), P
R.tetra(2-ethylbutyrate), PE.tetra(
isoheptanoate), PE tetra(isooctanoate), PE tetra(2-ethylhexanoate),
PE/tetra (isononylate) and PE and carbon number 4~
8 with a mixture of linear or branched carboxylic acids, etc.

Also, neopentyl polyols other than NPG, TMP and PE, i.e. 2-methyl-2-propylpropane-1,3
Examples include polyol esters of -diol, 2,2-diethylpropanediol, trimethylolethane, and trimethylolhexane and the above organic acids alone or in combination.

Phosphate esters include tricresyl phosphate,
Tritolyl phosphate, tri(2-ethylhexyl) phosphate, alkylphenyl phosphate, alkylphenyl phenyl phosphate, etc. can be used.

The polyalkylene glycol is a ring-opening polymer or a ring-opening copolymer of a linear or branched alkylene oxide in which the alkylene group has 2 to 5 carbon atoms, preferably 2 to 3 carbon atoms. Examples of alkylene oxide include ethylene oxide, propylene oxide, butylene oxide,
or a mixture thereof, preferably propylene oxide, preferably polyethylene glycol, polypropylene glycol, molecular weight range 1
00 to 2000, preferably 200 to 1000.

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

As the highly viscous oil which is a dispersoid, silicone oil, fluorinated oil, olefin oligomer, short chain polymethacrylate, polyalkylene glycol, etc. may be used.

The kinematic viscosity of these high viscosity oils is 10ms at 100°C.
"/s -100,000ms"/s, particularly preferably a kinematic viscosity of 30nn"/s to 30,000+s2/s
It is recommended to use high viscosity oil.

The silicone oil is represented by (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 O or an integer of 1 or more). The average molecular weight is in the range of 500 to 200,000.

Further, as the fluorinated oil, polychlorotrifluoroethylene (C1'5-CFCI) represented by the following formula is used.

(In the formula, n is 4 to 18) (Molecular M500 to 2,000.Kinematic viscosity at 100℃ 10
g++a"/s~1,000sm"/s〉formula, (wherein n is lO~60〉) Molecular weight 2,000~10,000.100℃
A material having a kinematic viscosity of 10 as'/s to 50 mm''/s can be used.

The α-olefin oligomer has 35 to 3 carbon atoms,
It is obtained by copolymerization of any type of homopolymer or two or more types selected from olefinic hydrocarbons having or not having branches in the range of 500, preferably 50 to 700, and having an average molecular weight of 500 to 700. 50,000. Preferably it is selected from 700-10,000 products, especially those with unsaturated bonds removed by hydrogenation. Preferred olefin oligomers include polybutene, α-olefin oligomer ethylene・α
-Olefin oligomers, etc.

The kinematic viscosity at 100°C is 10+u++”/s ” 1
0,000 m5''/s can be used.

In addition, polymethacrylate has a kinematic viscosity of 50 ms"/s at 100°C, represented by 10 o, ooo
Peng m”/s can be used.

The polyalkylene glycol is a ring-opening polymer or a ring-opening copolymer of a linear or branched alkylene oxide having an alkylene group having 2 to 5 carbon atoms, preferably 2 to 3 carbon atoms. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, or mixtures thereof, preferably propylene oxide, and preferably polyethylene glycol and polypropylene glycol having a molecular ff of 1500 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 have no compatibility. In the combination, it is necessary to make the combination non-compatible.

First, when silicone oil is used as the low viscosity oil, the dispersoid is insoluble except for the high viscosity silicone oil, and can be used as the lubricating oil M parabolite of the present invention. Particularly preferred is the case where polyethylene glycol or polypropylene glycol is used as the dispersoid.

Furthermore, when an olefin oligomer is used as a dispersion medium, silicone oil, short-chain polymethacrylate, polyethylene glycol, or polypropylene glycol may be used as the incompatible dispersoid.

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.

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

Furthermore, when f: acid ester is used as a dispersion medium, silicone oil or olefin oligomer is preferably used as a dispersoid.

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

Furthermore, in the present invention, the kinematic viscosity ratio at 100°C of low viscosity oil and high viscosity oil is 2 to
It is preferably in the range of 100,000, especially 5 to 3.00.
The lubricating oil composition of the present invention is preferably in the range of 0.0 The lubricating oil composition of the present invention is constituted by appropriately selecting such a kinematic viscosity ratio from the above-mentioned dispersion medium and dispersoid, and the kinematic viscosity ratio is If it is less than 2, the viscosity of the dispersion medium and dispersoid will be close, and the viscosity of the high viscosity oil will be so low that its characteristics will not be clear compared to the dispersion medium alone, and if it is more than 100,000, the oil will be in a solid state, which is preferable. In addition, the dispersoid is preferably used in a proportion of 0.5% to 50% by weight, preferably 1% by weight based on the dispersion medium.
It is preferable to use % to 30% by weight.

In order to disperse the dispersoid in the dispersion medium, it is preferable to mix the two liquid components using a mixer, a roll mill, etc. When the lubricating oil composition of the present invention is subjected to the effects of fluidization, stirring, etc. during use, Lubricating oil &
Although the dispersion medium and the dispersoid may be separated in the lubricating oil compound of the present invention, it is preferable to add a dispersant to the lubricating acid compound of the present invention to uniformly disperse it.

The dispersant is not particularly limited, but may be appropriately selected from low-molecular dispersants and polymer dispersants.

Specific examples of low-molecular dispersants include aliphatic or aromatic carboxylic acid metal salts or their esters, sulfate ester type metal salts, sulfonate ester type metal salts, phosphate ester type metal salts, and quaternary ammonium salts. etc., nonionic surfactants such as polyoxyethylene type, polyhydric alcohol type, alkylolamide type, etc., and as polymeric dispersants, lipophilic polar substances such as polyester, boria, boria, etc., and derivatives thereof. , alkenylsuccinimide, alkenylbenzylamine, petroleum resin (indencoumarone resin), various rosins and derivatives thereof, etc. The addition ratio of the dispersant is 0.05% by weight to 20% by weight.
% by weight can be used, preferably from 0.1% to 10% by weight.

The lubricating oil composition of the present invention may optionally contain a metal detergent (
At least one additive such as magnesium sulfonate, etc.), ashless detergent and dispersant (alkenyl succinimide, etc.), antioxidant (phenol, zinc thiophosphate, etc.), antifoaming agent (silicon, etc.) can do. In particular, metal detergents are 0.1% to 5.0% by weight, ashless detergent dispersants are 0.1% to 10.01i1%, and antioxidants are 0% by weight.
．． 1% to 1.5% by weight, antifoaming agent is 0.001%! i
It is preferable to set it as t% - 0.01 Tl amount %.

[Effect]

The lubricating oil composition of the present invention is prepared by dispersing a high viscosity oil in a low viscosity oil. It is thought that the liquid high viscosity oil swells at high temperatures and its volume fraction in the lubricating oil increases, resulting in an increase in viscosity and an improvement in the viscosity index (viscosity index improving property).
In addition, high viscosity particles support the load on the friction plane, maintain an oil film, and prevent metal-to-metal contact, reducing friction and preventing wear (improving wear resistance). Compared to commonly used viscosity index improvers, molecules are less likely to break due to shearing.
It was discovered that there was no decrease in viscosity (shear stability).

Therefore, the lubricating oil composition of the present invention is suitable for automobile engine oils such as gasoline engine oil and diesel engine oil, gear oils such as differential gear oil and transmission gear oil, power steering oil, automatic transmission oil, etc. ,
The lubricating oil composition is particularly suitable for use as an automotive lubricating oil and IIFc product such as a chassis oil such as a thick absorber oil.

[Example 1] Dispersion medium; Mineral oil; 100 neutral, viscosity 4.3 ms"/
3 (100℃) Dispersoid; Polypropylene glycol (trade name LB-3000, manufactured by Sanyo Kakai ■, viscosity 90+
ms”/s (100°C) Dispersant: Using alkenyl succinate ester (trade name Lubrizol 936, manufactured by Lubrizil), 1.0% by weight of dispersoid was added to mineral oil at 5°0.
%, 785% by weight, and 10.0% by weight, respectively, and a composition uniformly containing 3.0% by weight of a dispersant were mixed using a mixer to obtain a lubricating oil composition of the present invention.

The kinematic viscosity and viscosity index of each lubricating oil composition of the present invention were measured according to JIS K2283.

The results are shown as line A in FIG.
The numbers above 11 indicate the dispersoid content (% by weight).

For comparison, the kinematic viscosity and viscosity index of the same mineral oil containing 7.0% by weight of polymethacrylate (trade name: PLX-1019, manufactured by Nippon Acrylic), which is a viscosity index improver, are shown below. It is shown by line B in the same FIG.

Similarly, the viscosity indexes of mineral oils having various kinematic viscosities of 100 nitral mineral oil mixed with blystock were measured, and the results are shown as line C in FIG.

According to this, it can be seen that the lubricating oil composition of the present invention exhibits a higher viscosity index improving effect compared to those to which a viscosity index improver is added and those containing mineral oil alone.

[Example 2] (Abrasion resistance test) Example using mineral oil 100 neutral as a dispersoid! % of the polypropylene glycol used in Example 1 and 3% by weight of the succinic acid ester used in Example 1 as a dispersant were dispersed with a mixer to form the lubricating oil of the present invention.
1 bottom material was prepared.

As a comparison of this invention, mineral oil (100 neutral + bright stock) and mineral oil 100 neutral and polymethacrylate (PLX-1019, manufactured by Nippon Acrylic ■)
An additive oil for gear oil containing 7% by weight of Both oils are 6.3ms+”/s ~ 6.7m at 100℃
m"/s.A comparative test for abrasion resistance was carried out using a shell four-ball abrasion resistance tester.
According to EMD4172, the test conditions were 600 rpm,
The test was carried out under 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 (ms) was determined.

The results are shown by the dashed line in FIG.

In addition, the mark ○ on the broken line indicates the case of the lubricating oil composition of the present invention.
The inside of the mouth is the measurement result for an oil containing a viscosity index improver for gear oil. This shows that the lubricating oil composition of the present invention has excellent wear resistance compared to the oil containing a viscosity index improver for gear oil.

Furthermore, each of the lubricating oil composition of the present invention, the gear oil viscosity index improver-added oil, and mineral oil alone contained 0.5% by weight of zinc dialkyldithiophosphate, which is an anti-wear agent. A sex test was conducted. This result is shown in FIG. 2 as a solid line.

In addition, the ○ mark on the solid line indicates the lubricating oil of the present invention containing all lubricating acids, the mark in the mouth indicates the case of mineral oil with addition of a viscosity index improver for gear oil, and the mark indicates the case of mineral oil alone. .

According to this, it can be seen that the lubricating oil composition of the present invention has excellent wear resistance compared to the viscosity index improver-added oil for gear oil. Furthermore, the wear resistance can be improved by adding an anti-wear agent, and it is clear that this effect is particularly remarkable compared to oils containing viscosity index improvers for gear oils and mineral oils.

[Example 3] (Shear stability test) The lubricating oil of the present invention prepared in Example 2, the viscosity index improver-added oil for gear oil (containing 7% by weight of polymethacrylate), and the viscosity index for engine oil Oil 41a, which is an improver-added oil (containing 5% by weight of polymethacrylate) and a mineral oil (100 neutral + bright stock), both have a viscosity of 6°3 mtn”/s to 6,7 m at 100°C.
s”/s, but for each individual case, the lubricating oil shear stability test was conducted using a sample irradiation time of 30 minutes, and the Japan Petroleum Institute standard JP l-63-29-
88. The relationship between shear time (minutes) and viscosity change rate is shown in FIG. 3, and the relationship between shear time (minutes) and viscosity index is shown in FIG.

In the figure, the case of the lubricating oil composition of the present invention is marked with ○, the case of gear oil with viscosity index improver added is marked with Δ, the case of engine oil with viscosity index improver added is shown in the mouth, and the case of mineral oil alone is shown. is indicated with a ・mark.

This shows that the lubricating oil composition of the present invention exhibits superior shear stability compared to oils containing a viscosity index improver.

〔Effect of the invention〕

The lubricating oil composition of the present invention consists of a low-viscosity oil as a dispersion medium, a high-viscosity oil as a dispersoid that is substantially incompatible with the dispersion medium, and a dispersant further contained as necessary. It has a high viscosity index improvement effect, has excellent abrasion resistance, and exhibits excellent shear stability.
It is particularly excellent as a lubricating oil composition for automobile engine oil, gear oil, and chassis oil.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the viscosity index improving property of the lubricating oil composition of the present invention, FIG. 2 is a diagram for explaining the wear resistance of the lubricating oil NMTC of the present invention, FIG. FIG. 4 is a diagram for explaining the shear stability of the lubricating oil composition of the present invention. Applicant: Toenen Co., Ltd.

Claims (2)

[Claims] (1) An automotive lubricating oil composition comprising a low-viscosity oil as a dispersion medium and a high-viscosity oil as a dispersoid that is substantially incompatible with the dispersion medium. (2) The automotive lubricating oil composition according to claim 1, further comprising a dispersant.