JP5311748B2 - Lubricating oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubrication oil composition equipped both with fuel-saving performance and sufficient durability of gears, bearings or the like. <P>SOLUTION: This lubrication oil is characterized by containing the base oil of the lubrication oil consisting of (A) 20 to 95 mass% base oil of the lubrication oil adjusted to have 1.5 to 10 mm<SP>2</SP>/s dynamic viscosity at 100&deg;C, &ge;60%CP, &ge;100 viscosity index and &le;0.3 mass% sulfur content and (B) 5 to 80 mass% highly viscous base oil of the lubrication oil having &gt;8 and &le;300 mm<SP>2</SP>/s dynamic viscosity at 100&deg;C based on the total of the base oil, also containing (C) 0.01 to 8 mass% sulfur-based extreme-pressure additive, (D) 0.01 to 5 mass% phosphorus-sulfur-based extreme-pressure additive and (E) 0.01 to 25 mass% viscosity index-improving agent having &le;50,000 weight-average molecular weight based on the whole amount of the composition, and having &ge;0.01 mass% amount of phosphorus and &ge;0.05 mass% amount of sulfur in the composition. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a lubricating oil composition, and more particularly, to an automatic transmission, a manual transmission, a continuously variable transmission, and a final reduction gear for automobiles having excellent oxidation stability, low temperature viscosity characteristics, load resistance, and gear fatigue life. The present invention relates to a suitable lubricating oil composition, and more particularly to a lubricating oil composition suitable as a manual transmission oil and / or a final reduction gear.

  In recent years, there has been an urgent need to save fuel and make long drains for automobiles, construction machinery, agricultural machinery, etc. in response to environmental issues such as reducing carbon dioxide emissions. Engines, transmissions, final reduction gears, compressors Also, devices such as hydraulic devices are strongly required to contribute to fuel saving and long drain. Therefore, the lubricating oil used in these is required to have a longer life while reducing the stirring resistance and frictional resistance as compared with the conventional one.

  As means for reducing the fuel consumption of the transmission and the final reduction gear, there are an increase in the viscosity index of the lubricating oil, an improvement in the low temperature performance, and a reduction in the viscosity of the composition. For example, among automatic transmissions, automatic transmissions and continuously variable transmissions for automobiles have torque converters, wet clutches, gear bearing mechanisms, oil pumps, hydraulic control mechanisms, etc., and manual transmissions and final reduction gears have gear bearing mechanisms. By increasing the viscosity index of the lubricating oil used in these oils and lowering the viscosity to a lower viscosity grade, the stirring resistance of torque converters, wet clutches, gear bearing mechanisms, oil pumps, etc. The frictional resistance is reduced, and the power transmission efficiency is improved, so that the fuel efficiency of the automobile can be improved. Further, by improving the low temperature performance, it is possible to improve not only the low temperature startability at the start of cold districts and winter seasons but also the fuel efficiency.

  However, reducing the base oil viscosity and adding a large amount of viscosity index improver to reduce the viscosity of the lubricating oil or to increase the viscosity index significantly reduces fatigue life and extreme pressure, resulting in pitting and seizure. This may cause problems with the transmission and the like. Furthermore, if the amount of sulfur-based extreme pressure agent or phosphorus-sulfur-based extreme pressure agent is increased in order to improve fatigue life or extreme pressure properties, oxidation stability will be significantly deteriorated, and it is difficult to achieve a long life. I know that there is.

As conventional gear oils, those in which various additives are blended with synthetic base oils and / or mineral oil base oils have been proposed as those capable of improving synchro characteristics, extreme pressure properties, oxidation stability, and the like ( For example, see Patent Documents 1 to 3.) However, none of these compositions is intended to improve fuel efficiency, and the effect of low temperature viscosity characteristics, fatigue life, extreme pressure properties and oxidation stability on the combination of base oil composition, viscosity index improver and extreme pressure agent. Has not been studied at all, especially in manual transmission oils and / or final reduction gears, by optimizing the base oil composition, viscosity index improver and extreme pressure agent, low temperature viscosity characteristics, fatigue life, extreme pressure and oxidation There is no disclosure of a method for achieving all of stability.
JP 11-323371 A JP-A-10-316987 Japanese Patent Laid-Open No. 10-17785

  The present invention has been made in view of such circumstances, and its purpose is to optimize the base oil composition, the viscosity index improver and the extreme pressure agent, and the blending amount thereof, low temperature viscosity characteristics, fatigue life, extreme pressure properties. And a lubricating oil composition characterized by having both oxidation stability and an automatic transmission, a manual transmission, a continuously variable transmission, a final reduction gear, etc. for automobiles, particularly a manual transmission oil and / or a final transmission. The present invention provides a lubricating oil composition suitably used for a reduction gear.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have identified a lubricating base oil comprising a specific lubricating base oil and a specific lubricating base oil having a higher viscosity than this at a specific ratio. It has been found that a lubricating oil composition comprising the extreme pressure agent and a specific viscosity index improver can solve the above problems, and has completed the present invention.

That is, the present invention is a base oil based on a total amount, (A) a kinematic viscosity at ^{100 ℃ 1.5~8mm 2 / s,%} C P 60 or more, a viscosity index of 100 or more, 0.3 wt sulfur % Of lubricating base oil 20 to 95% by mass adjusted to not more than% and (B) 5 to 80% by mass of high viscosity lubricating base oil having a kinematic viscosity at 100 ° C. exceeding 8 mm ² / s and not exceeding 300 mm ² / s. (C) 0.01 to 8% by mass of a sulfur-based extreme pressure agent, (D) 0.01 to 5% by mass of a phosphorus-sulfur extreme pressure agent, based on the total amount of the composition. (E) A viscosity index improver having a weight average molecular weight of 50000 or less is contained in an amount of 0.01 to 25% by mass, the amount of phosphorus in the composition is 0.01% by mass or more, and the amount of sulfur is 0.05% by mass or more. The lubricating oil composition characterized by these.
The present invention also relates to the above lubricating oil composition, wherein the (A) lubricating base oil has a% _CP of 70 or more, a viscosity index of 120 or more, and a sulfur content of 0.1% by mass or less.
The present invention also relates to the above (B) a high viscosity sulfur content of the lubricating base oil is 0.1 wt% or more,% C _A is the lubricating oil composition, wherein 1 or more.
Furthermore, this invention relates to the said lubricating oil composition characterized by being used for a manual transmission and / or a final reduction gear.

  Since the lubricating oil composition of the present invention has the above-described configuration, the stirring resistance is reduced and the low-temperature viscosity characteristics are improved. It is extremely effective as a fuel-saving and long-life type lubricating oil composition that has never been used since it has excellent fatigue life performance such as bearings and gears, extreme pressure properties, and excellent antioxidant properties.

Hereinafter, the lubricating oil composition of the present invention will be described.
(A) a lubricating base oil in the present invention, a kinematic viscosity at ^{100 ℃ 1.5~8mm 2 / s,%} C P 60 or more, a viscosity index of 100 or more, a sulfur content of 0.3 wt% or less It is a lubricating base oil that is prepared, and a mineral lubricating base oil, a synthetic lubricating base oil, and a mixture thereof can be used.

  As a mineral oil base oil, a lubricating oil fraction obtained by subjecting crude oil to atmospheric distillation and vacuum distillation is subjected to solvent removal, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining. In addition, paraffinic and naphthenic mineral oil base oils, normal paraffins, isoparaffins, and the like, which are refined alone or in appropriate combination of two or more purification treatments such as sulfuric acid washing and clay treatment, can be mentioned. These base oils may be used alone or in combination of two or more at any ratio.

Preferred mineral oil base oils include the following base oils.
(1) Distilled oil obtained by atmospheric distillation of paraffin-based crude oil and / or mixed-base crude oil;
(2) Vacuum distillation distillate (WVGO) of paraffinic base oil and / or mixed base oil of atmospheric distillation residue;
(3) a Fischer-Tropsch wax produced by a wax and / or GTL process obtained by a lubricant dewaxing step;
(4) Mild hydrocracking treatment oil (MHC) of one or two or more mixed oils selected from the above (1) to (3);
(5) A mixed oil of two or more oils selected from the above (1) to (4);
(6) Degassed oil (DAO) of (1), (2), (3), (4) or (5);
(7) The mild hydrocracking treatment oil (MHC) of (6) above;
(8) A mixed oil of two or more kinds of oils selected from the above (1) to (7) is used as a raw oil, and this raw oil and / or a lubricating oil fraction recovered from this raw oil is usually used. Oil obtained by refining by the refining method and recovering the lubricating oil fraction

  The normal refining method here is not particularly limited, and a refining method used in the production of the lubricating base oil can be arbitrarily employed. Examples of conventional purification methods include (a) hydrorefining such as hydrocracking and hydrofinishing, (b) solvent purification such as furfural solvent extraction, and (c) dewaxing such as solvent dewaxing and catalytic dewaxing. And (d) white clay refining with acid clay and activated clay, and (e) chemical (acid or alkali) purification such as sulfuric acid washing and caustic soda washing. In the present invention, one or more of these can be used in any combination and in any order.

The mineral oil base oil used in the present invention is particularly preferably a base oil obtained by further subjecting the base oil selected from the above (1) to (8) to the following treatment.
That is, the base oil selected from the above (1) to (8) is used as it is or the lubricating oil fraction recovered from this base oil is hydrocracked or wax isomerized, and the product is used as it is or from now on. Collect the fraction, and then perform dewaxing treatment such as solvent dewaxing or contact dewaxing, and then solvent refining treatment, or after solvent refining treatment, dewaxing such as solvent dewaxing or contact dewaxing Hydrocracked mineral oil and / or wax isomerized isoparaffinic base oil produced by treatment is preferably used. This hydrocracked mineral oil and / or hydrorefined mineral oil is preferably 30% by mass or more, more preferably 50% by mass or more, further preferably 70% by mass or more, particularly preferably 100% by mass based on the total amount of component (A). It is desirable to use it.

  Synthetic lubricating base oils include poly α-olefins or hydrides thereof, isobutene oligomers or hydrides thereof, isoparaffins, alkylbenzenes, alkylnaphthalenes, diesters (eg, ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate , Ditridecyl adipate, di-2-ethylhexyl sebacate, etc.), polyol esters (eg, trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyoxy Examples include alkylene glycol, dialkyl diphenyl ether, polyphenyl ether, and the like.

  Preferable synthetic lubricating base oils include poly α-olefins. The poly α-olefin is typically an α-olefin oligomer or co-oligomer having 2 to 32 carbon atoms, preferably 6 to 16 carbon atoms (for example, 1-octene oligomer, 1-decene oligomer, 1-dodecene oligomer). , Ethylene-propylene co-oligomer and the like) and hydrides thereof.

  There is no particular limitation on the production method of the poly α-olefin, but for example, aluminum trichloride, boron trifluoride, or boron trifluoride and water, alcohol (for example, ethanol, propanol or butanol), carboxylic acid, or ester (for example, And polymerization of α-olefins in the presence of a polymerization catalyst such as a Friedel-Crafts catalyst containing a complex with ethyl acetate or ethyl propionate).

(A) The upper limit of the kinematic viscosity at 100 ° C. of the lubricating base oil is 8 mm ² / s, preferably 7 mm ² / s or less. On the other hand, the lower limit of the kinematic viscosity at 100 ° C. of the (A) lubricating base oil is 1.5 mm ² / s, preferably 2.5 mm ² / s or more, more preferably 4.5 mm ² / s or more, Particularly preferably, it is 5 mm ² / s or more. By setting the kinematic viscosity at 100 ° C. to 8 mm ² / s or less, a lubricating oil composition having excellent low-temperature viscosity characteristics can be obtained. In addition, by setting the kinematic viscosity at 100 ° C. to 1.5 mm ² / s or more, particularly 5 mm ² / s or more, oil film formation is sufficient, and excellent lubricity as a manual transmission oil and / or final reduction gear is obtained. In addition, it becomes possible to obtain a lubricating oil composition having a lower evaporation loss of the base oil under high temperature conditions.

Further, the upper limit value of the kinematic viscosity at 40 ° C. of the (A) lubricating base oil is not particularly limited, but is usually 100 mm ² / s or less, preferably 50 mm ² / s or less, more preferably 40 mm ² / s or less. It is. On the other hand, the lower limit of the kinematic viscosity at 40 ° C. of the (A) lubricating base oil is not particularly limited, but is usually 5 mm ² / s or more, preferably 15 mm ² / s or more, more preferably 25 mm ² / s. As described above, it is particularly preferably 30 mm ² / s or more. By setting the kinematic viscosity at 40 ° C. to 100 mm ² / s or less, it is possible to obtain a lubricating oil composition that is excellent in low-temperature viscosity characteristics and fluid resistance is small, so that the frictional resistance at the lubrication point is smaller. Further, by setting the kinematic viscosity at 40 ° C. to 5 mm ² / s or more, particularly 25 mm ² / s or more, oil film formation is sufficient, and excellent lubricity as a manual transmission oil and / or final reduction gear is achieved. It becomes possible to obtain a lubricating oil composition having a smaller base oil evaporation loss under conditions.

Moreover,% C _P of (A) a lubricating base oil in the present invention is 60 or more, preferably 70 or more, more preferably 75 or more, it is desirable particularly preferably 80 or more, preferably 95 or less, more Preferably it is 90 or less. (A) With the% C _P of the lubricating base oil more than 60, it increases more the effect of viscosity index and while improving the oxidation stability of component (B) and extreme pressure agents, good composition by fatigue life In addition, by setting it to 95 or less, it is possible to obtain a lubricating oil composition in which the movement of the machine is not hindered even at low temperatures.
Moreover,% C _A of (A) a lubricating base oil in the present invention has no particular restriction, for the same reason as described above, preferably 5 or less, more preferably 3 or less, more preferably 2 or less, particularly Preferably it is 0.5 or less.
Although% C _N of (A) a lubricating base oil in the present invention is not particularly limited, for the same reason as above, preferably 40 or less, more preferably 30 or less, more preferably 25 or less, in particular It is preferably 23 or less, preferably 5 or more, more preferably 10 or more, and still more preferably 15 or more.
Herein, the _term% C P, and% _{C A} and% _{C N} is determined by the method specified in ASTM D 3238-85, 100 parts per to the total number of carbon atoms of the paraffin carbon number, aromatic carbon atoms The 100 fraction for the total carbon number and the 100 fraction for the total carbon number of the naphthene carbon number are shown respectively.

  The viscosity index of the (A) lubricating base oil in the present invention is 100 or more, preferably 110 or more, more preferably 120 or more, and particularly preferably 125 or more. By setting the viscosity index to 100 or more, it is possible to obtain a composition that exhibits good viscosity characteristics from low temperature to high temperature and is excellent in oxidation stability.

  In addition, the sulfur content of the (A) lubricating base oil in the present invention is 0.3% by mass or less, preferably 0.1% by mass or less, and more preferably 0.02% by mass or less. , 0.005% by mass or less is particularly preferable. By reducing the sulfur content of the component (A), it is possible to obtain a composition that is more excellent in oxidative stability of the composition.

  Further, the CCS viscosity at −30 ° C. of the (A) lubricating base oil in the present invention is not particularly limited, but is preferably 10,000 mPa · s or less, more preferably 8000 mPa · s or less, and further preferably 6500 mPa · s. It is as follows. By reducing the CCS viscosity of the component (A), a composition superior in low-temperature startability can be obtained. Moreover, (A) Although there is no restriction | limiting in particular in the minimum of CCS viscosity in -30 degreeC of lubricating base oil, Improve oxidation stability, fatigue life, and seizure resistance as a manual transmission oil and / or final reduction gear. Is preferably 2000 mPa · s or more, more preferably 3000 mPa · s or more, and still more preferably 4000 mPa · s or more. In addition, it is particularly preferable that the CCS viscosity of the component (A) is 3000 to 8000 mPa · s in that it is particularly excellent in the balance between low temperature startability, oxidation stability, fatigue life, and seizure resistance. In addition, the CCS viscosity at −30 ° C. referred to in the present invention means a viscosity measured in accordance with JIS K 2010-1993.

  Further, the pour point of the (A) lubricating base oil in the present invention is not particularly limited, but it is preferably −10 ° C. or less, more preferably −12.5 ° C., although it depends on the viscosity grade of the lubricating base oil. Hereinafter, it is more preferably −15 ° C. or lower. By reducing the pour point of the component (A), it is possible to obtain a lubricating oil composition having better low temperature fluidity. In addition, the pour point as used in the field of this invention means the pour point measured based on JISK2269-1987.

  Further, T10 in the GC distillation of (A) lubricating base oil in the present invention is not particularly limited, but is preferably 300 ° C or higher, more preferably 330 ° C or higher, further preferably 370 ° C or higher, particularly preferably 400 ° C. It is above, Preferably it is 500 degrees C or less, More preferably, it is 460 degrees C or less, More preferably, it is 440 degrees C or less, Most preferably, it is 420 degrees C or less. (A) T90 in the GC distillation of the lubricating base oil is not particularly limited, but is preferably 400 ° C or higher, more preferably 450 ° C or higher, further preferably 500 ° C or higher, particularly preferably 520 ° C or higher. The temperature is preferably 600 ° C. or lower, more preferably 560 ° C. or lower, and further preferably 540 ° C. or lower. Furthermore, (90) T90-T10 in the GC distillation of the lubricating base oil is not particularly limited, but is preferably 60 ° C. or higher, more preferably 80 ° C. or higher, further preferably 90 ° C. or higher, particularly preferably 100 ° C. or higher. It is preferably 200 ° C. or lower, more preferably 150 ° C. or lower, further preferably 130 ° C. or lower, and particularly preferably 120 ° C. or lower. By adjusting T10, T90 and T90-T10 of the component (A) to the above ranges, particularly T10 to 300 to 460 ° C. and T90 to 400 to 560 ° C., low temperature viscosity characteristics, suppression of evaporation loss, oxidation stability of the composition In addition, the fatigue life and seizure resistance can be improved in a balanced manner. In addition, T10 in GC distillation of (A) component is 380-460 degreeC by the point which is especially excellent in the low-temperature startability as manual transmission oil and / or final reduction gear, and the balance of oxidation stability, fatigue life, and seizure resistance. , T90 is particularly preferably 500 to 560 ° C. In addition, T10 and T90 in the GC distillation referred to in the present invention mean a 10% distillation point (° C.) and a 90% distillation point (° C.), respectively, by gas chromatography distillation, and conform to ASTM D 2887-97. Measured.

  The lubricating base oil (A) in the present invention may be a mixture of two or more mineral base oils or synthetic base oils as long as the above-mentioned provisions of the present invention are satisfied. It may be a mixture of mineral oil base oil and synthetic oil base oil. And the mixing ratio of 2 or more types of base oil in the said mixture can be chosen arbitrarily.

  In the present invention, the content of the (A) lubricating base oil is 20% by mass or more, preferably 30% by mass or more, more preferably 40% by mass or more, and particularly preferably 55% by mass based on the total amount of the base oil. % Or more, 95% by mass or less, preferably 90% by mass or less, more preferably 80% by mass or less, and particularly preferably 70% by mass or less. (A) When the content of the lubricating base oil is less than 20% by mass, the low-temperature viscosity characteristics are deteriorated, which is not preferable. When the content exceeds 95% by mass, the content of the (B) component becomes small, and thus fatigue prevention is achieved. The properties and the seizure-preventing properties are deteriorated, which is not preferable.

The (B) high-viscosity lubricant base oil in the present invention is a lubricant base oil having a kinematic viscosity at 100 ° C. of more than 10 mm ² / s and 300 mm ² / s or less.
The (B) high-viscosity lubricant base oil in the present invention is a high-viscosity mineral oil base oil as long as the kinematic viscosity at 100 ° C. is adjusted to exceed 10 mm ² / s and not more than 300 mm ² / s. May be a high-viscosity synthetic lubricant, may be a mixture of two or more high-viscosity mineral oil base oils, or may be a mixture of two or more high-viscosity synthetic oils It may be a mixture of one or more high-viscosity mineral oil-based lubricating base oils and one or more high-viscosity synthetic oil-based lubricating oils. The mixing ratio of the two or more high-viscosity lubricating base oils in the mixture can be arbitrarily selected.
The mineral oil base oil as the component (B) is the same as the mineral oil base oil described in the section of the component (A), the type and the production method thereof. ) To (8), one or more steps of solvent refining such as furfural solvent extraction, dewaxing such as solvent dewaxing and catalytic dewaxing, and hydrorefining such as hydrofinishing What is manufactured through this is preferable.

  Specific examples of the high-viscosity synthetic lubricating base oil include poly α-olefins or hydrides thereof, isoparaffin, alkylbenzene, alkylnaphthalene, polyester, polyoxyalkylene glycol, dialkyldiphenyl ether, polyphenyl ether, and the like.

Preferable examples of the high viscosity synthetic lubricant base oil include poly α-olefins. Examples of poly α-olefins include isobutene oligomers, 1-octene oligomers, 1-decene oligomers, ethylene-propylene oligomers, etc., having 2 to 32 carbon atoms, preferably 2 to 16 carbon atoms, and particularly preferably α having 8 to 16 carbon atoms. -Polymers of olefins, copolymers thereof, or hydrides thereof.
The above oligomers are produced by oligomerization of 1-olefins in the presence of a metal oligomerization catalyst that is a supported metal with a low valence state. Preferred catalysts include low valence chromium on silica made by reduction of chromium using carbon monoxide as the reducing agent. The oligomerization is performed at a temperature selected according to the desired viscosity for the resulting oligomer (US Pat. Nos. 4,827,064, 4,870,073, etc.). Higher viscosity materials can be produced, where oligomerization temperatures below about 90 ° C. are used to produce higher molecular weight oligomers (US Pat. Nos. 5,012,020, 5,146,021, etc.).

Other preferable examples of the high-viscosity synthetic lubricating base oil include ester-based lubricating oils. Specifically, a polyhydric alcohol having a neopentyl structure such as neopentyl glycol, trimethylolpropane, pentaerythritol and the like, an ester obtained from a monocarboxylic acid and a polycarboxylic acid, or a monocarboxylic acid ester and a polycarboxylic acid ester Examples include complex esters obtained by adjusting the degree of polymerization so that the kinematic viscosity at 100 ° C. exceeds 10 mm ² / s and is 300 mm ² / s or less by esterification or transesterification. These may contain, for example, alkylene oxide or polyalkylene oxide in the molecule.

  Examples of the monocarboxylic acid include butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, elca Linear fatty acids such as acids, 2-ethylhexanoic acid, isooctylic acid, isononanoic acid, isocapriic acid, isolauric acid, isomyristic acid, isopalmitic acid, isostearic acid, isoarachidic acid, synthetic fatty acid by Koch method, synthetic alcohol by Gerve method Branched fatty acids such as fatty acids derived from these and mixtures thereof.

  Examples of the polycarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, dodecane-1,12-dicarboxylic acid, plasylic acid, dimer acid, and phthalic acid. Dibasic acids such as isophthalic acid and terephthalic acid, propylene-1,2,3-tricarboxylic acid, propane-1,2,3-tricarboxylic acid, 2-oxypropane-1,2,3-tricarboxylic acid, 4- Tribasic acids such as oxypentane-1,3,4-tricarboxylic acid, 2-oxyheptadecane-1,2,3-tricarboxylic acid, hemimellitic acid, trimellitic acid, trimesic acid, prenic acid, melophanoic acid, pyro A merit acid etc. and these mixtures are mentioned. Particularly preferred are dibasic acids such as adipic acid, azelaic acid, dodecane-1,12-dicarboxylic acid and dimer acid.

  Examples of the carboxylic acid ester and polycarboxylic acid ester include esters of the carboxylic acid or polycarboxylic acid with a lower alcohol (for example, methanol, ethanol, octanol, etc.).

  In addition, as a manufacturing method of the said complex ester, it reacts at 100-250 degreeC, for example, preferably 140-240 degreeC by the process of 1 step | paragraph or 2 steps | paragraphs or more, unreacted substance is distilled off, and catalyst is used. Examples of the method include removal, washing with water, and purification by dehydration by heating under reduced pressure. Here, toluene, benzene, xylene or the like may be used as an azeotropic dehydration solvent, or an inert gas such as nitrogen may be introduced for the purpose of removing reaction water, or the reaction may be performed under reduced pressure. As the catalyst, for example, an acidic catalyst such as sulfuric acid or paratoluenesulfonic acid, an alkaline catalyst such as potassium hydroxide, lithium hydroxide, or lithium acetate, or a metal oxide such as zinc oxide may be used.

Another preferred example of the high-viscosity synthetic lubricating base oil is polyoxyalkylene glycol. Examples of the polyoxyalkylene glycol include 3 to 10 carbon atoms such as propylene oxide, trimethylene oxide, butylene oxide, α-methyl-trimethylene oxide, 3,3′-dimethyl-trimethylene oxide, tetrahydrofuran, and dioxane. Is a polyoxypropylene glycol synthesized by ring-opening polymerization or ring-opening copolymerization of an alkylene oxide having 3 to 5 carbon atoms so that the kinematic viscosity at 100 ° C. is 10 to 300 mm ² / s by selecting the degree of polymerization. A polyoxyalkylene glycol is mentioned.

(B) The upper limit of the kinematic viscosity at 100 ° C. of the high-viscosity lubricating base oil is 300 mm ² / s, preferably 200 mm ² / s or less, more preferably 150 mm ² / s or less, and even more preferably 60 mm ² / s. Hereinafter, it is particularly preferably 40 mm ² / s or less. On the other hand, (B) the kinematic viscosity at 100 ° C. of the high-viscosity lubricant base oil is more than 10 mm ² / s, more preferably 15 mm ² / s or more, still more preferably 20 mm ² / s or more, particularly preferably 30 mm ² / s. s or more. If the kinematic viscosity at 100 ° C. is 10 mm ² / s or less, the effect on fatigue life is small, and if it exceeds 300 mm ² / s, the effect on fatigue life is only small enough to increase the kinematic viscosity. , Each is not preferred.

  Further, the sulfur content of the (B) high-viscosity lubricant base oil is not particularly limited, but is preferably 0% by mass or 1% by mass or less, more preferably 0.1 to 0.9% by mass, and still more preferably. Is 0.3 to 0.8 mass%, particularly preferably 0.4 to 0.7 mass%. (B) It is considered that the sulfur-containing compound in the high-viscosity lubricating oil contributes to the improvement of the fatigue life. (B) When the sulfur content of the high-viscosity lubricating base oil is 0.3% by mass or more, fatigue occurs. The contribution to the improvement of the service life is increased. Moreover, since it exists in the tendency for the oxidation stability of a composition to fall when the sulfur content of (B) high-viscosity lube base oil is too high, it is desirable that it is 1 mass% or less.

Although% _{C N} is not particularly limited high viscosity lubricating base oil (B), from the viewpoint of excellent fatigue life, preferably 15 to 40, more preferably 20 to 30.
Although% C _A is not particularly limited high viscosity lubricating base oil (B), from the viewpoint of excellent fatigue life, preferably 0-10, more preferably 5-8.
Although (B)% _{C P} of the high-viscosity lubricant base oil is not particularly limited, from the viewpoint of excellent fatigue life, preferably 55 to 100, more preferably 60 to 80, even more preferably at 65 to 70 .

In addition, although there is no restriction | limiting in particular about the property of the lubricating base oil which consists of said (A) and (B), the point can adjust the property as follows in the point of a fuel-saving performance improvement and the improvement of a fatigue life. preferable.
When the lubricating oil composition of the present invention is used for a manual transmission and / or a final speed reducer, the kinematic viscosity at 100 ° C. of the lubricating base oil composed of the above (A) and (B) is 13 to 33. 16 mm ² / s.

In addition, the sulfur content of the lubricating base oil composed of (A) and (B) is preferably 0% by mass or 0.3% by mass or less, more preferably 0 when used for an automatic transmission. .2% by mass or less, more preferably 0.02 to 0.15% by mass, and particularly preferably 0.04 to 0.13% by mass. Further, when used for manual transmission and / or final reduction gear, the sulfur content of the lubricating base oil composed of (A) and (B) is preferably 0% by mass or 0.6% by mass. % Or less, more preferably 0.05 to 0.5% by mass, particularly preferably 0.1 to 0.4% by mass, and particularly preferably 0.2 to 0.35% by mass.
Further, the (A) and% _{C N} of the lubricating base oil consisting of (B) is preferably from 10 to 40, more preferably 17 to 40, more preferably 18 to 40, particularly preferably at 20 to 30 .

  The lubricating oil composition of the present invention comprises a sulfur-based extreme pressure agent as the component (C). Examples of sulfur-based extreme pressure agents include sulfurized fats and oils, sulfurized olefins, dihydrocarbyl polysulfides, dithiocarbamates, thiadiazoles, and benzothiazoles.

  Examples of sulfurized fats and oils include sulfurized lard, sulfurized rapeseed oil, sulfurized castor oil, sulfurized soybean oil, and sulfurized rice bran oil; disulfide fatty acids such as sulfurized oleic acid; and sulfurized esters such as methyl sulfide oleate. .

Examples of the sulfurized olefin include compounds represented by the following general formula (1).
R ¹¹ -S _x -R ¹² (1)
In the general formula (1), R ¹¹ represents an alkenyl group having 2 to 15 carbon atoms, R ¹² represents an alkyl group or alkenyl group having 2 to 15 carbon atoms, and x represents an integer of 1 to 8.
This compound can be obtained by reacting an olefin having 2 to 15 carbon atoms or a dimer or tetramer thereof with a sulfurizing agent such as sulfur or sulfur chloride. As the olefin, for example, propylene, isobutene, diisobutene and the like are preferably used.

Dihydrocarbyl polysulfide is a compound represented by the following general formula (2).
R ¹³ -S _y -R ¹⁴ (2)
In General Formula (2), R ¹³ and R ¹⁴ are each independently an alkyl group having 1 to 20 carbon atoms (including a cycloalkyl group), an aryl group having 6 to 20 carbon atoms, and an aryl having 7 to 20 carbon atoms. Represents an alkyl group, which may be the same or different from each other, and y represents an integer of 2 to 8;

Specific examples of R ¹³ and R ¹⁴ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and various pentyl groups. Groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups, various dodecyl groups, cyclohexyl groups, phenyl groups, naphthyl groups, tolyl groups, xylyl groups, benzyl groups, and phenethyl groups. be able to.

  Specific examples of preferred dihydrocarbyl polysulfides include dibenzyl polysulfide, di-tert-nonyl polysulfide, didodecyl polysulfide, di-tert-butyl polysulfide, dioctyl polysulfide, diphenyl polysulfide, and dicyclohexyl polysulfide. It is done.

  Specific examples of dithiocarbamates include compounds represented by the following general formula (3) or (4).

In the general formulas (3) and (4), R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and R ²⁰ each independently represent a hydrocarbon group having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. , R ²¹ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, e represents an integer of 0 to 4, and f represents an integer of 0 to 6. .
Examples of the hydrocarbon group having 1 to 30 carbon atoms include an alkyl group, a cycloalkyl group, an alkylcycloalkyl group, an alkenyl group, an aryl group, an alkylaryl group, and an arylalkyl group.

  Examples of thiadiazoles include a 1,3,4-thiadiazole compound represented by the following general formula (5), a 1,2,4-thiadiazole compound represented by the general formula (6), and a general formula (7). Mention may be made of 1,4,5-thiadiazole compounds.

In the general formulas (5) to (7), R ²² , R ²³ , R ²⁴ , R ²⁵ , R ²⁶ and R ²⁷ may be the same or different, and each independently represents a hydrogen atom or 1 to 30 carbon atoms. And g, h, i, j, k, and l each independently represent an integer of 0 to 8.
Examples of the hydrocarbon group having 1 to 30 carbon atoms include an alkyl group, a cycloalkyl group, an alkylcycloalkyl group, an alkenyl group, an aryl group, an alkylaryl group, and an arylalkyl group.

  In the present invention, one or more selected from these components (C) can be used, but among these, from the viewpoint of fatigue life, extreme pressure, wear resistance, oxidation stability, etc. It is desirable to use polysulfides and / or sulfurized fats and oils, and it is particularly preferable to use polysulfides.

  The component (C) in the present invention usually has a sulfur content of 5 to 60% by mass, and is particularly excellent in seizure resistance, and is preferably 15% by mass or more, more preferably 20% by mass or more. Particularly preferably, the content is 25% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less from the viewpoint of fatigue life, extreme pressure property, wear resistance, oxidation stability and the like.

  The blending amount of the component (C) in the lubricating oil composition of the present invention is 0.01 to 8% by mass, preferably 0.1 to 5% by mass, based on the total amount of the composition. More preferably, it is 0.01 to 4% by mass in terms of elemental sulfur, more preferably 0.1 to 2% by mass, and still more preferably 0.2 to 1.5 in terms of being able to be further increased. % By mass, particularly preferably 0.3 to 0.95% by mass.

The lubricating oil composition of the present invention comprises a phosphorus-sulfur extreme pressure agent as component (D).
(D) The phosphorus-sulfur extreme pressure agent is not particularly limited as long as it contains phosphorus and sulfur in the molecule. For example, monothiophosphite, dithiophosphite, trithiophosphite, Examples thereof include monothiophosphates, dithiophosphates, trithiophosphates, and derivatives thereof. Of these, dithiophosphates and derivatives thereof are preferred, and dithiophosphates are particularly preferred. These usually contain C2-C30 hydrocarbon groups.

The dithiophosphoric acid ester is, for example, at least one selected from dithiophosphoric acid, dithiophosphoric acid monoesters, dithiophosphoric acid diesters, dithiophosphoric acid triesters, and these usually contain a hydrocarbon group having 2 to 30 carbon atoms. To do.
Dithiophosphate derivatives include metal salts of dithiophosphates, amine salts of dithiophosphates, reaction products of dithiophosphates with dienes such as dicyclopentadiene, β-dithiophosphorylated carboxylic acids and their derivatives, etc. Is mentioned. Among these, those containing no metal are particularly preferable.

  Examples of the hydrocarbon group having 2 to 30 carbon atoms include an alkyl group, a cycloalkyl group, an alkylcycloalkyl group, an alkenyl group, an aryl group, an alkylaryl group, and an arylalkyl group.

Examples of the alkyl group include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl And alkyl groups such as a group, a heptadecyl group, and an octadecyl group (these alkyl groups may be linear or branched).
As a cycloalkyl group, C5-C7 cycloalkyl groups, such as a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group, can be mentioned, for example.
Examples of the alkylcycloalkyl group include a methylcyclopentyl group, a dimethylcyclopentyl group, a methylethylcyclopentyl group, a diethylcyclopentyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a methylethylcyclohexyl group, a diethylcyclohexyl group, a methylcycloheptyl group, a dimethylcyclopentyl group, and the like. Examples thereof include an alkylcycloalkyl group having 6 to 11 carbon atoms such as a heptyl group, a methylethylcycloheptyl group, and a diethylcycloheptyl group (the substitution position of the alkyl group with the cycloalkyl group is also arbitrary).

  Examples of alkenyl groups include butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, and An alkenyl group such as an octadecenyl group (these alkenyl groups may be linear or branched, and the position of the double bond is also optional).

As an aryl group, aryl groups, such as a phenyl group and a naphthyl group, can be mentioned, for example.
As the alkylaryl group, for example, tolyl group, xylyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, decylphenyl group, And an alkylaryl group having 7 to 18 carbon atoms such as undecylphenyl group and dodecylphenyl group (the alkyl group may be linear or branched, and the substitution position on the aryl group is arbitrary). it can.
Examples of the arylalkyl group include arylalkyl groups having 7 to 12 carbon atoms such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, and phenylhexyl group (these alkyl groups may be linear). It may be branched).

  In addition, these (D) component in this invention is 0.01-5 mass% on the basis of composition whole quantity from points, such as fatigue life, extreme pressure property, abrasion resistance, and oxidation stability, Preferably, the content is 0.05 to 3% by mass, but more preferably 0.01 to 0.5% by mass, more preferably 0.02 to 0.3% by mass in terms of phosphorus element, in order to further improve the fatigue life performance. %, Particularly preferably 0.03 to 0.1% by mass, most preferably 0.04 to 0.06% by mass. For the same reason, the blending amount of the component (D) is preferably 0.01 to 1% by mass, more preferably 0.03 to 0.8% by mass in terms of sulfur element, based on the total amount of the composition. More preferably, the content is 0.05 to 0.5% by mass, and particularly preferably 0.06 to 0.1% by mass, and the mass ratio (P / S) of phosphorus and sulfur resulting from these components (D) Depending on the sulfur content resulting from the component (C), it is considered that there is an optimum range, preferably 0.1 to 1, more preferably 0.3 to 0.8, particularly preferably 0.4. ~ 0.6.

  In addition, although the ratio of the blending amount of the component (C) and the component (D) in the present invention is not particularly limited, the amount of sulfur (Sc) and (D) due to the component (C) is superior in terms of seizure resistance. The mass ratio (Sc / Sd) with the component-derived sulfur amount (Sd) is preferably 1 to 100, more preferably 5 to 50, still more preferably 8 to 20, and particularly preferably 10 to 15. . In the present invention, the component (C) is preferably a polysulfide having a sulfur content of 15% by mass or more, particularly preferably a sulfur content of 15% by mass or more, and the Sc / Sd ratio is as described above. Is particularly desirable.

The lubricating oil composition of the present invention comprises a viscosity index improver having a weight average molecular weight of 50,000 or less as the component (E).
The viscosity index improver according to the present invention is formulated for the purpose of further improving fatigue life, extreme pressure after long-term use, wear resistance or low temperature fluidity, and has a weight average molecular weight of 50,000 or less. Preferably it is 40,000 or less, Most preferably, it is a non-dispersion type viscosity index improver and / or a dispersion type viscosity index improver of 10,000-35,000.

  Specifically, as the non-dispersion type viscosity index improver, a homopolymer of a monomer (E-1) selected from the compounds represented by the following formulas (8), (9) and (10) or Examples thereof include two or more copolymers of monomer (E-1) or hydrides thereof. On the other hand, as the dispersion type viscosity index improver, specifically, two or more kinds of monomers (E-2) selected from the compounds represented by the general formulas (11) and (12) or One or two or more of monomers (E-1) selected from those obtained by introducing an oxygen-containing group into the hydride or compounds represented by the general formulas (8) to (10) and the general formula (11 ) And (12), a copolymer with one or more monomers (E-2) selected from the compounds represented by (12), or a hydride thereof.

In the above formula (8), R ¹ represents hydrogen or a methyl group, and R ² represents an alkyl group having 1 to 30 carbon atoms.
Specific examples of the alkyl group having 1 to 30 carbon atoms represented by R ² include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl. Examples thereof include a group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group (these alkyl groups may be linear or branched).

In the above formula (9), R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents hydrogen or a hydrocarbon group having 1 to 12 carbon atoms.
Specific examples of the hydrocarbon group having 1 to 12 carbon atoms represented by R ⁴ include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, Alkyl groups such as decyl group, undecyl group, dodecyl group (these alkyl groups may be linear or branched); cycloalkyl groups having 5 to 7 carbon atoms such as cyclopentyl group, cyclohexyl group and cycloheptyl group; methyl Cyclopentyl group, dimethylcyclopentyl group, methylethylcyclopentyl group, diethylcyclopentyl group, methylcyclohexyl group, dimethylcyclohexyl group, methylethylcyclohexyl group, diethylcyclohexyl group, methylcycloheptyl group, dimethylcycloheptyl group, methylethylcycloheptyl group, diethyl Such as cycloheptyl group An alkylcycloalkyl group having 6 to 11 carbon atoms (the substitution position of these alkyl groups with the cycloalkyl group is arbitrary);
Alkenyl groups such as butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, etc. (These alkenyl groups may be linear or branched, and position of double bond Is also optional);
Aryl group such as phenyl group, naphthyl group: alkylaryl group having 7 to 12 carbon atoms such as tolyl group, xylyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group (these alkyl groups) May be linear or branched, and the position of substitution on the aryl group is also arbitrary); carbon number of benzyl, phenylethyl, phenylpropyl, phenylbutyl, phenylpentyl, phenylhexyl, etc. 7-12 arylalkyl groups (these alkyl groups may be linear or branched); and the like.

In the above formula (10), X ¹ and X ² are each independently a hydrogen atom, an alkoxy group having 1 to 18 carbon atoms (—OR ⁹ : R ⁹ is an alkyl group having 1 to 18 carbon atoms) or 1 carbon atom. to 18 monoalkylamino group ^{(-NHR 10: R} 10 is an alkyl group having 1 to 18 carbon atoms).

In the formula (11), R ⁵ represents a hydrogen atom or a methyl group, R ⁶ represents an alkylene group having 1 to 30 carbon atoms, Y ¹ represents ¹ to 2 nitrogen atoms, and 0 to 2 oxygen atoms. 1 represents an amine residue or heterocyclic residue, and m is 0 or 1.
Specific examples of the alkylene group having 1 to 30 carbon atoms represented by R ⁶ include ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, Examples include an undecylene group, a dodecylene group, a tridecylene group, a tetradecylene group, a pentadecylene group, a hexadecylene group, a heptadecylene group, and an octadecylene group (these alkylene groups may be linear or branched).
Specific examples of the group represented by Y ¹ include dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, anilino group, toluidino group, xylidino group, acetylamino group, benzoylamino group, Examples thereof include a morpholino group, a pyrrolyl group, a pyrrolino group, a pyridyl group, a methylpyridyl group, a pyrrolidinyl group, a piperidinyl group, a quinonyl group, a pyrrolidonyl group, a pyrrolidono group, an imidazolino group, and a pyrazino group.

In the above formula (12), R ⁷ represents a hydrogen atom or a methyl group, and Y ² represents an amine residue or a heterocyclic residue containing 1 to 2 nitrogen atoms and 0 to 2 oxygen atoms.
Specific examples of the group represented by Y ² include a dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, an anilino group, a toluidino group, a xylidino group, an acetylamino group, a benzoylamino group, and a morpholino group. Pyrrolyl group, pyrrolino group, pyridyl group, methylpyridyl group, pyrrolidinyl group, piperidinyl group, quinonyl group, pyrrolidonyl group, pyrrolidono group, imidazolino group, pyrazino group and the like.

Preferable examples of the monomer (E-1) are specifically alkyl acrylates having 1 to 30 carbon atoms, alkyl methacrylates having 1 to 30 carbon atoms, olefins having 2 to 20 carbon atoms, styrene, methylstyrene, and anhydrous maleic acid. Examples thereof include acid esters, maleic anhydride amides and mixtures thereof.
Preferable examples of the monomer (E-2) include dimethylaminomethyl methacrylate, diethylaminomethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-methyl-5-vinylpyridine, morpholinomethyl methacrylate, morpholinoethyl. Examples thereof include methacrylate, N-vinyl pyrrolidone and a mixture thereof.

  Copolymerization of a copolymer of one or more monomers selected from the above (E-1) compound and one or more monomers selected from the (E-2) compound. The molar ratio is generally about monomer (E-1): monomer (E-2) = 80: 20 to 95: 5. The production method is arbitrary, but usually a copolymer can be easily obtained by radical solution polymerization of monomer (E-1) and monomer (E-2) in the presence of a polymerization initiator such as benzoyl peroxide. It is done.

  Specific examples of the viscosity index improver which is the component (E) of the present invention include non-dispersed or dispersed polymethacrylates, non-dispersed or dispersed ethylene-α-olefin copolymers or hydrides thereof, poly Examples include isobutylene or a hydride thereof, a styrene-diene hydrogenated copolymer, a styrene-maleic anhydride copolymer, and a polyalkylstyrene. Among these, non-dispersion type or dispersion type polymethacrylates, particularly non-dispersion type polymethacrylates are preferable because they are excellent in the effect of improving the viscosity index and the effect of improving the low temperature characteristics.

  The blending amount of the viscosity index improver which is the component (E) of the present invention is 0.01 to 25% by mass, preferably 0.1 to 15% by mass, more preferably 0.5, based on the total amount of the composition. -10 mass%, More preferably, it is 3-8 mass%. When the blending amount of the viscosity index improver exceeds 25% by mass, it is not preferable because it is difficult to maintain the initial extreme pressure for a long period of time.

  The lubricating oil composition of the present invention is excellent in oxidation stability, fatigue life and seizure resistance due to the above-described configuration. It is preferable to blend at least one additive selected from the group consisting of powders, alkaline earth metal detergents, antioxidants and friction modifiers.

Examples of the ashless dispersant include the following nitrogen compounds. These can be used alone or in combination of two or more.
(F-1) A succinimide having at least one alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule, or a derivative thereof (F-2) an alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule Or a derivative thereof (F-3) a polyamine having at least one alkyl or alkenyl group having 40 to 400 carbon atoms in the molecule, or a derivative thereof

  More specific examples of the succinimide (F-1) include compounds represented by the following general formula (13) or (14).

In the general formula (13), R ³¹ represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms, and a represents an integer of 1 to 5, preferably 2 to 4.
In the general formula (14), R ³² and R ³³ individually represent an alkyl group or an alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms, and b is 0 to 4, preferably 1 to 3. Indicates an integer.

  In the succinimide, a so-called monotype succinimide represented by the general formula (13) in which succinic anhydride is added to one end of the polyamine is added by imidization, and succinic anhydride is added to both ends of the polyamine. The so-called bis-type succinimide represented by the general formula (14) in the form is included, and any of them or a mixture thereof can be used in the composition of the present invention.

  More specifically, examples of the benzylamine (F-2) include compounds represented by the following general formula (15).

In the general formula (15), R ³⁴ represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms, and c represents an integer of 1 to 5, preferably 2 to 4.
The benzylamine is obtained by reacting, for example, polyolefin (for example, propylene oligomer, polybutene, ethylene-α-olefin copolymer) with phenol to form alkylphenol, and then adding formaldehyde and polyamine (for example, diethylenetriamine, triethylenetetramine). , Tetraethylenepentamine, pentaethylenehexamine, etc.) can be obtained by reacting them by Mannich reaction.

More specific examples of the polyamine (F-3) include compounds represented by the following general formula (16).
^{_{R 35 -NH- (CH 2 CH 2}} NH) d -H (16)
In the general formula (16), R ³⁵ represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350, and d represents an integer of 1 to 5, preferably 2 to 4.
The polyamine is, for example, chlorinated polyolefin (for example, propylene oligomer, polybutene, ethylene-α-olefin copolymer, etc.) and then ammonia or polyamine (for example, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepenta). Min, pentaethylenehexamine, etc.).

  Although the nitrogen content in the nitrogen compound is arbitrary, from the viewpoints of wear resistance, oxidation stability, friction characteristics, etc., the nitrogen content is usually preferably 0.01 to 10% by mass, more preferably. It is desirable to use 0.1 to 10% by mass.

  Examples of the derivative of the nitrogen compound include those having 2 to 30 carbon atoms such as monocarboxylic acid having 2 to 30 carbon atoms (fatty acid, etc.), oxalic acid, phthalic acid, trimellitic acid, and pyromellitic acid. A so-called acid-modified compound in which a part or all of the remaining amino group and / or imino group is neutralized or amidated by the action of polycarboxylic acid; A so-called boron-modified compound obtained by neutralizing or amidating a part or all of the amino group and / or imino group; a sulfur-modified compound obtained by allowing a sulfur compound to act on the nitrogen compound; and an acid on the nitrogen compound And a modified compound in which two or more kinds of modifications selected from modification, boron modification, and sulfur modification are combined.

When the ashless dispersant is blended in the composition of the present invention, the blending amount is not particularly limited, but is preferably 0.1 to 10% by mass, more preferably 0.5 to 8.0% by mass based on the total amount of the composition. %. When the content of the ashless dispersant is less than 0.1% by mass, the effect of dispersing and solubilizing degradation products such as sludge is insufficient. When the content exceeds 10% by mass, the low-temperature fluidity of the composition is low. Since it deteriorates significantly, each is not preferable.
In the present invention, among these ashless dispersants, at least a number average molecular weight of 1000 to 2500, preferably 1200 to 1500 poly (iso) butenyl groups, and boron-free succinimide type. An ashless dispersant is preferably blended, and the blending amount is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and preferably 0.4% by mass as the nitrogen amount based on the total amount of the composition. Hereinafter, it is more preferably 0.1% by mass or less, and particularly preferably 0.01 to 0.02% by mass from the balance between the acid value increase suppressing effect and the fatigue life.

In the composition of the present invention, it is not necessary to blend an alkaline earth metal detergent, but by blending this, the fatigue life is further improved, and the initial extreme pressure property and the extreme pressure property after prolonged use are improved. Can be improved.
The alkaline earth metal detergent that can be blended in the composition of the present invention is preferably a basic metal detergent having a total base number of 20 to 450 mgKOH / g, preferably 50 to 400 mgKOH / g. The total base number is defined in JIS K2501, “Petroleum products and lubricating oils-Neutralization number test method”. It means the total base number measured by the perchloric acid method based on When the total base number of the alkaline earth metal detergent is less than 20 mgKOH / g, the effect of improving fatigue life and extreme pressure properties is insufficient, whereas when the total base number exceeds 450 mgKOH / g, it is structural. Are unstable, and the storage stability of the composition deteriorates.

  Specific examples of alkaline earth metal detergents having a total base number of 20 to 450 mg KOH / g include alkaline earth metal sulfonates, alkaline earth metal phenates and alkaline earth metal salicylates. One type or two or more types of metal detergents selected from among them can be used.

  The alkaline earth metal sulfonate, alkaline earth metal phenate and alkaline earth metal salicylate have alkyl aromatic sulfonic acid, alkylphenol, alkylphenol sulfide, alkylphenol as long as the total base number is in the range of 20 to 450 mgKOH / g. The Mannich reaction product, alkylsalicylic acid, or the like directly reacts with an alkaline earth metal base such as an alkaline earth metal oxide or hydroxide of magnesium and / or calcium, or once such as sodium salt or potassium salt. Not only neutral salts (normal salts) obtained by replacing alkali metal salts with alkaline earth metal salts, but also neutral salts (normal salts) and excess alkaline earth metal salts or alkaline earths. Metal bases (alkali earth metal hydroxides and oxidations) ) In the presence of water, or an overbased salt obtained by reacting a neutral salt (normal salt) with an alkaline earth metal base in the presence of carbon dioxide ( Superbasic salts) are also included. These reactions are usually performed in a solvent (an aliphatic hydrocarbon solvent such as hexane, an aromatic hydrocarbon solvent such as xylene, a light lubricant base oil, or the like). In addition, metal detergents are usually marketed in a state diluted with a light lubricating base oil or the like, and are available, but generally the metal content is 1.0 to 20% by mass, It is desirable to use 2.0 to 16% by mass.

  In the lubricating oil composition of the present invention, when an alkaline earth metal detergent is blended, the blending amount is not particularly limited, but is preferably 0.05 to 4.0% by mass based on the total amount of the composition, More preferably, it is 0.1 mass% or more, 3.0 mass% or less, Preferably it is 1 mass% or less, Most preferably, it is 0.5 mass% or less.

As the antioxidant, any phenolic compound or amine compound that is generally used in lubricating oils can be used.
Specifically, alkylphenols such as 2-6-di-tert-butyl-4-methylphenol, and bisphenols such as methylene-4,4-bisphenol (2,6-di-tert-butyl-4-methylphenol). , Naphthylamines such as phenyl-α-naphthylamine, dialkyldiphenylamines, zinc dialkyldithiophosphates such as zinc di-2-ethylhexyldithiophosphate, (3,5-di-tert-butyl-4-hydroxyphenyl) fatty acid ( (Propionic acid etc.) or (3-methyl-5-tertbutyl-4-hydroxyphenyl) fatty acid (propionic acid etc.) and mono- or polyhydric alcohols such as methanol, octanol, octadecanol, 1,6 hexadiol, neo Pentyl glycol, thiodiethylene glycol, Triethylene glycol, esters of pentaerythritol and the like.
One kind or two or more kinds of compounds arbitrarily selected from these can be contained in any amount, but the content is usually 0.01 to 5. based on the total amount of the lubricating oil composition. It is preferably 0% by mass.

  As the friction modifier, any compound usually used as a friction modifier for lubricating oils can be used, but an alkyl group or alkenyl group having 6 to 30 carbon atoms, particularly a linear alkyl group having 6 to 30 carbon atoms. Alternatively, amine compounds, imide compounds, alcohols, fatty acids, fatty acid esters, fatty acid amides, fatty acid metal salts and the like having at least one linear alkenyl group in the molecule are preferably used.

  Examples of the amine compound include linear or branched, preferably linear aliphatic monoamines having 6 to 30 carbon atoms, linear or branched, preferably linear aliphatic polyamines, or fatty acids thereof. An alkylene oxide adduct of a group amine can be exemplified. Examples of the imide compound include a succinimide having a linear or branched alkyl group or alkenyl group having 6 to 30 carbon atoms and / or a modified compound thereof using carboxylic acid, boric acid, phosphoric acid, sulfuric acid, or the like. . Examples of fatty acid esters include esters of linear or branched, preferably linear, fatty acids having 7 to 31 carbon atoms with aliphatic monohydric alcohols or aliphatic polyhydric alcohols. Examples of fatty acid amides include amides of linear or branched, preferably linear fatty acids having 7 to 31 carbon atoms, and aliphatic monoamines or aliphatic polyamines. Examples of the fatty acid metal salt include an alkaline earth metal salt (magnesium salt, calcium salt, etc.) or zinc salt of a linear or branched, preferably linear fatty acid having 7 to 31 carbon atoms.

  In the present invention, one kind or two or more kinds of compounds arbitrarily selected from the above friction modifiers can be contained in any amount, and the content thereof is usually 0.00 on the basis of the total amount of the composition. It is 01-5.0 mass%, Preferably it is 0.03-3.0 mass%.

  In the lubricating oil composition of the present invention, for the purpose of further improving its performance, if necessary, in addition to the above-mentioned additives, a corrosion inhibitor, a rust inhibitor, a demulsifier, a metal deactivator, a flow You may mix | blend various additives, such as a point depressant, a rubber swelling agent, an antifoamer, and a coloring agent, individually or in combination.

  Examples of the corrosion inhibitor include benzotriazole, tolyltriazole, thiadiazole, and imidazole compounds.

  Examples of the rust inhibitor include petroleum sulfonate, alkylbenzene sulfonate, dinonylnaphthalene sulfonate, alkenyl succinic acid ester, and polyhydric alcohol ester.

  Examples of the demulsifier include polyalkylene glycol nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene alkyl naphthyl ether.

  Examples of metal deactivators include imidazoline, pyrimidine derivatives, alkylthiadiazoles, mercaptobenzothiazoles, benzotriazoles or derivatives thereof, 1,3,4-thiadiazole polysulfide, 1,3,4-thiadiazolyl-2,5-bis. Examples include dialkyldithiocarbamate, 2- (alkyldithio) benzimidazole, and β- (o-carboxybenzylthio) propiononitrile.

  As the pour point depressant, a known pour point depressant can be arbitrarily selected according to the lubricating base oil. However, a polymethacrylate having a weight average molecular weight of more than 50,000 and not more than 500,000, preferably 80000 to 200,000 is used. preferable.

  As the antifoaming agent, any compound usually used as an antifoaming agent for lubricating oil can be used, and examples thereof include silicones such as dimethyl silicone and fluorosilicone. One or two or more compounds arbitrarily selected from these can be blended in any amount.

  As the colorant, any compound that is usually used can be used, and any amount can be blended.

  When these additives are contained in the lubricating oil composition of the present invention, the content is based on the total amount of the composition, and 0.005 to 5% by mass for the corrosion inhibitor, the rust inhibitor, and the demulsifier, respectively. The point depressant and the metal deactivator are usually selected in the range of 0.005 to 1% by mass, the antifoaming agent is 0.0005 to 1% by mass, and the colorant is 0.001 to 1.0% by mass.

The sulfur content of the lubricating oil composition of the present invention (extreme pressure agent, lubricating oil base oil, the total amount of sulfur due to other additives) is from the point of extreme pressure and fatigue life improvement and oxidation stability, 0.05% by mass or more, preferably 0.1% by mass or more, more preferably 0.4% by mass or more, further preferably 0.8% by mass or more, and 4% by mass in terms of superior oxidation stability. % Or less, preferably 3% by mass or less, more preferably 2% by mass or less, further preferably 1.8% by mass or less, and particularly preferably 1.3% by mass or less.
The phosphorus content of the lubricating oil composition of the present invention is 0.01% by mass or more, preferably 0.03% by mass or more, more preferably 0.03% by mass, from the viewpoint of extreme pressure / fatigue life improvement and oxidation stability. 04 mass% or more, preferably 0.3 mass% or less, more preferably 0.25 mass% or less, further preferably 0.2 mass% or less, further preferably 0.1 mass% or less, particularly preferably 0. 0.05% by mass or less.
Further, the mass ratio (S / P) between the sulfur content and the phosphorus content contained in the lubricating oil composition of the present invention is not particularly limited, but from the viewpoint of extreme pressure / fatigue life improvement and oxidation stability, Preferably it is 1-100, More preferably, it is 11-50, More preferably, it is 15-40, Most preferably, it is 25-35.

In addition, the lubricating oil composition of the present invention has a kinematic viscosity at 100 ° C. of 30 mm ² / s or less, preferably in order to further improve fuel economy performance as a combined oil for conventional manual transmission and final reduction gear. Is 25 mm ² / s or less, more preferably 20 mm ² / s or less, particularly preferably 18 mm ² / s or less, preferably 10 mm ² / s or more, more preferably 13.5 mm ² / s or more, and particularly preferably 15 mm ² / s. It is desirable to set it as s or more. The kinematic viscosity at 40 ° C. is preferably 200 mm ² / s or less, more preferably 170 mm ² / s or less, and particularly preferably 150 mm ² / s or less.

  In addition, the BF viscosity at −26 ° C. of the composition is preferably 150 Pa · s or less, in that the extreme pressure and fatigue life as a combined oil for a manual transmission and a final reduction gear are further increased, and the low temperature startability balance is excellent. More preferably, it is 100 Pa · s or less, more preferably 70 Pa · s or less, preferably 10 Pa · s or more, more preferably 30 Pa · s or more, and particularly preferably 50 Pa · s or more. In addition, BF viscosity at -26 degreeC here means the Brookfield at -26 degreeC measured based on ASTMD2983.

  In addition, the lubricating oil composition of the present invention is not particularly limited in the viscosity index of the composition, but is preferably 100 or more, more preferably from the viewpoint of further improving extreme pressure properties and fatigue life, and excellent low temperature startability balance. 120 or more, preferably 200 or less, more preferably 160 or less, and still more preferably 130 or less.

  The lubricating oil composition of the present invention has an excellent fatigue life and can reduce the agitation resistance caused by the lubricating oil as compared with conventional products. For example, for automatic transmissions, continuously variable transmissions, manual transmissions, and final reduction gears It is possible to contribute to the improvement of the fuel consumption of an automobile by using it for an automotive transmission such as a manual transmission and / or a final reduction gear.

  Hereinafter, the present invention will be described more specifically using examples and comparative examples, but the present invention is not limited to these examples.

(Examples 1-3 and Comparative Examples 1-5)
Various lubricating base oils and additives shown in Table 1 were blended to prepare lubricating oil compositions (Examples 1 to 3) and comparative lubricating oil compositions (Comparative Examples 1 to 5) according to the present invention. did. The amount of each additive added is based on the total amount of the composition.
About each obtained composition, the following test methods and test conditions evaluated the low-temperature fluidity | liquidity test, oxidation stability evaluation, pitching prevention property evaluation, and extreme pressure evaluation. The performance evaluation results are also shown in Table 1.

(1) Low temperature fluidity test Based on ASTM D 2983, the BF viscosity at -26 ° C of each lubricating oil composition was measured. The obtained results are shown in Table 1. In this test, the smaller the value of the BF viscosity, the better the low temperature fluidity.

(2) Oxidation stability evaluation First, the acid value of each lubricating oil composition was measured. Next, in accordance with JIS K 2514, each lubricating oil composition was forcibly deteriorated under conditions of 150 ° C. and 96 hours at ISOT, and the acid value thereof was measured. The increase was determined. The obtained results are shown in Table 1. In this test, the smaller the acid value increase, the better the oxidation stability. Moreover, the kinematic viscosity (100 degreeC) before and behind a test was measured, and viscosity increase prevention property was calculated | required from the viscosity ratio before and behind a test. In this test, the smaller the viscosity ratio, the better the oxidation stability.

(3) Pitching prevention evaluation FZG tester was used as a tester, and fatigue life was measured as follows. The time until the occurrence of pitching in the test piece was defined as the fatigue life.
Test piece: C gear Test condition: 10 stages Oil temperature: 80 ° C
Surface pressure: 6.4 GPa

(4) Extreme pressure property evaluation Using a shell four-ball tester as a tester, load resistance was measured in accordance with ASTM D2596.

As is clear from the results shown in Table 1, the lubricating oil compositions (Examples 1 to 3) of the present invention all have excellent fatigue lives.
On the other hand, when a base oil not corresponding to the component (A) is used (Comparative Example 1), it can be seen that the low temperature performance and the antioxidant performance are inferior. Moreover, when not using any of (B) component, (C) component, (D) component, and (E) component (Comparative Examples 2-5), it turns out that a fatigue life and extreme pressure property are inferior.

Claims (5)

In the base oil the basis of the total amount, (A) a kinematic viscosity at ^{100 ℃ 1.5~8mm 2 / s,%} C P 60 or more, a viscosity index of 100 or more, by adjusting the sulfur content to 0.3 wt% or less Consisting of 20 to 95% by mass of a lubricant base oil and (B) 5 to 80% by mass of a high-viscosity lubricant base oil having a kinematic viscosity at 100 ° C. of more than 8 mm ² / s and not more than 300 mm ² / s, at 100 ° C. To a lubricating base oil having a kinematic viscosity of 13 to 16 mm ² / s, 0.01 to 8% by mass of (C) a sulfur-based extreme pressure agent and (D) a phosphorus-sulfur-based extreme pressure based on the total amount of the composition. 0.01 to 5% by mass of the agent, (E) 0.01 to 25% by mass of the viscosity index improver having a weight average molecular weight of 50000 or less, the amount of phosphorus in the composition being 0.01% by mass or more, and the amount of sulfur There is at least 0.05 wt%, a kinematic viscosity at 100 ° C. is 15 ~ 20 mm ² / s For manual transmission, characterized in that there and / or final reduction gear lubricating oil composition. 2. The lubricating oil composition according to claim 1, wherein the (A) lubricating oil base oil has a% _CP of 70 or more, a viscosity index of 120 or more, and a sulfur content of 0.1% by mass or less. (B) the high viscosity sulfur content of the lubricating base oil is 0.1 wt% or more,% C _A lubricating oil composition according to claim 1 or 2, characterized in that 1 or more.   The lubricating oil according to any one of claims 1 to 3, wherein T10 in the GC distillation of the lubricating base oil (A) is adjusted to 300 to 460 ° C and T90 is adjusted to 400 to 560 ° C. Composition. In the base oil the basis of the total amount, (A) a kinematic viscosity at ^{100 ℃ 1.5~8mm 2 / s,%} C P 60 or more, a viscosity index of 100 or more, by adjusting the sulfur content to 0.3 wt% or less Consisting of 20 to 95% by mass of a lubricant base oil and (B) 5 to 80% by mass of a high-viscosity lubricant base oil having a kinematic viscosity at 100 ° C. of more than 8 mm ² / s and not more than 300 mm ² / s, at 100 ° C. To a lubricating base oil having a kinematic viscosity of 13 to 16 mm ² / s, 0.01 to 8% by mass of (C) a sulfur-based extreme pressure agent and (D) a phosphorus-sulfur-based extreme pressure based on the total amount of the composition. 0.01 to 5% by mass of the agent, and (E) 0.01 to 25% by mass of a viscosity index improver having a weight average molecular weight of 50000 or less, the amount of phosphorus in the composition is 0.01% by mass or more, sulfur content is 0.05 mass% or more, kinematic viscosity at 100 ° C. 15-20 manufacturing method of the manual transmission for and / or final reduction gear lubricating oil composition characterized by obtaining m lubricating oil composition is 2 ^{/ s.}