JPH11106776A - Lubricating oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lubricating oil compsn. excellent in many characteristics and useful as an internal combustion engine oil by adding, to a base oil. specified amts. of an alkenyl- or alkylsuccinimide compd. previously reacted with a cyclic carbonate and a boron-contg. alkenyl- or alkylsuccinimide compd. SOLUTION: This compsn. is prepd. by dissolving or dispersing 0.5-15 wt.% alkenyl- or alkylsuccinimide compd. previously reacted with a cyclic carbonate (A) and 0. 5-15 wt. % boron-contg. alkenyl- or alkylsuccinimide compd. (B) in a base oil, the sum of ingredients A and B being pref. 1.0-15 wt.%. Pref., the compsn. further contains 0.5-20 wt.% metal-contg. cleaning agent, 0.1-3.0 wt.% zinc alkyldithiophosphate, 0.02-5.0 wt.% molybdenum compd., 0.1-5.0 wt.% phenol or amine compd., and 1-20 wt.% viscosity index improver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lubricating oil composition, and more particularly to a lubricating oil composition useful as a lubricating oil for an internal combustion engine.

[0002]

2. Description of the Related Art In recent years, an internal combustion engine having a high energy output has been developed. Also, internal combustion engines equipped with a waste gas treatment device and an exhaust noise reduction device have become common. The tendency to extend the replacement time of engine oil, that is, lubricating oil, has recently become remarkable. Therefore, demands for various performances of engine oil tend to be more and more severe.

[0003] In the case of diesel engines, delays in fuel injection timing, exhaust gas recirculation (EGR) systems, and prolonged periods of use of engine oil increase insolubles (especially soot and suit) in engine oil. This may cause wear of engine parts and increase in viscosity of engine oil. In addition, use of high output of engine and high top ring,
And the sealing of the engine also causes an increase in the top groove deposits on the piston.

With respect to gasoline engines, in recent years,
In order to suppress the decrease in the activity of the exhaust gas treatment catalyst, the reduction of the phosphorus content in the engine oil has been promoted, but this is actually the case of the zinc dialkyldithiophosphate (Zn-DTP) in the engine oil. This means that the amount of addition is reduced, which causes deposits (sludge, varnish, etc.) in the engine oil at medium and low temperatures, and causes wear of various parts of the engine.

[0005] Therefore, it exhibits high cleanliness not only in high temperature conditions but also in low and middle temperatures, and suppresses wear of engine parts such as piston rings and valve trains (cams and followers).
Stabilizes the dispersion of insolubles generated in engine oil,
The development of an engine oil that can effectively prevent such agglomeration is awaited.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a lubricating oil composition having various excellent properties and which can be advantageously used particularly as an engine oil for an internal combustion engine.

[0007]

According to the present invention, there is provided a base oil containing 0.5 to 15% by weight of an alkenyl or alkyl succinimide compound treated with a cyclic carbonate, and 0.5 to 15% by weight of a boron-containing alkenyl or alkyl succinimide compound. ~ 15% by weight dissolved or dispersed in a lubricating oil composition.

[0008] The lubricating oil composition of the present invention further comprises 0.5 to
20% by weight of a metal-containing detergent, and / or 0.1 to
Desirably, it contains 3.0% by weight of zinc dialkyldithiophosphate. Further, the lubricating oil composition of the present invention further comprises:
It is desirable to contain 0.02-5.0% by weight of the molybdenum compound. The content of the molybdenum compound in the lubricating oil composition is 10 to 250 in terms of molybdenum atomic weight.
It is desirable that the amount is 0 ppm.

Preferably, the lubricating oil composition of the present invention further comprises at least one antioxidant selected from the group consisting of phenol compounds and amine compounds, in an amount of 0.1 to 5.0% by weight. Further, it is desirable to include the viscosity index improver in an amount of 1 to 20% by weight.

The alkenyl or alkyl succinimide compound reacted with the cyclic carbonate contained in the lubricating oil composition of the present invention comprises an succinic anhydride substituted with an alkenyl or alkyl group and an average of 4 parts per molecule.
It is preferably obtained by a reaction with a polyalkylenepolyamine containing from 10 to 10 nitrogen atoms, and is preferably further subjected to a post-reaction treatment with a cyclic carbonate compound. The alkenyl or alkyl in the alkenyl or alkyl succinimide compound treated with the cyclic carbonate has an average molecular weight of 10
Desirably, it is derived from polybutene of from 00 to 2700 (particularly from 1900 to 2700).

Further, the alkenyl or alkyl of the boron-containing alkenyl or alkyl succinimide compound contained in the lubricating oil composition of the present invention has an average molecular weight of 1
Desirably, it is derived from 000-2700 polybutene.

The total content of the alkenyl or alkyl succinimide compound and the boron-containing alkenyl or alkyl succinimide compound which has been reacted with the cyclic carbonate in the lubricating oil composition of the present invention is 1.
It is desirable to be in the range of 0 to 15% by weight. And
It is desirable that the alkenyl or alkyl succinimide compound reacted with the cyclic carbonate and the boron-containing alkenyl or alkyl succinimide compound are contained in a weight ratio of 2: 8 to 8: 2.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The lubricating oil composition of the present invention is prepared by dissolving or dispersing an alkenyl or alkyl succinimide compound and a boron-containing alkenyl or alkyl succinimide compound reacted with a cyclic carbonate in a base oil which is a major component. , And preferably further contains a metal-containing detergent and zinc dialkyldithiophosphate. If necessary, a molybdenum-containing compound, a phenolic or amine-based antioxidant, a viscosity index improver, and other various additives are added.

[0014] The base oil may be a mineral oil, a synthetic oil, or a mixture thereof. Base oil is 10
It is desirable to use one having a kinematic viscosity at 0 ° C. in the range of ² to 50 mm ² / s. The mineral oil-based base oil is preferably one obtained by treating a mineral oil-based lubricating oil fraction by appropriately combining a treatment method such as solvent refining or hydrogenation treatment. Particularly, highly hydrogenated refined base oil (for example, A base oil having a viscosity index of 100 to 150, an aromatic content of 5% by weight or less, and a nitrogen and sulfur content of 50 ppm or less, respectively, is preferably used.

The synthetic oils (synthetic lubricating base oils) include, for example, poly-α-olefins which are polymers of α-olefins having 3 to 12 carbon atoms, sebacic acid, azelaic acid and adipine represented by dioctyl sebacate. Dialkyl diester which is an ester of a dibasic acid such as an acid and an alcohol having 4 to 12 carbon atoms; polyol ester which is an ester of 1-trimethylolpropane or pentaerythritol and a monobasic acid having 3 to 12 carbon atoms; Alkyl benzenes having 9 to 40 alkyl groups can be exemplified.

The mineral base oil and the synthetic base oil can be used alone. If desired, two or more mineral base oils or two or more synthetic base oils can be used in combination. Can also be used. If desired, a mineral oil-based base oil and a synthetic oil-based base oil can be used in any combination.

The lubricating oil composition of the present invention contains 0.5 to 15% by weight of an alkenyl or alkyl succinimide compound treated with a cyclic carbonate, and a boron-containing alkenyl or alkyl succinimide compound (or a borated alkenyl or alkyl succinimide compound). Compound) in a dissolved or dispersed state in an amount of 0.5 to 15% by weight.

The alkenyl or alkyl succinimide compound treated with the above-mentioned cyclic carbonate is an ashless dispersant, and is composed of a high molecular weight alkenyl or alkyl-substituted succinic anhydride and an average of 4% per molecule.
It can be obtained by reacting with a polyalkylene polyamine containing 10 to 10 (preferably 5 to 7) nitrogen atoms, and then subjecting the reaction product to a post-reaction treatment with a cyclic carbonate compound. The details of the alkenyl or alkyl succinimide compound treated with the cyclic carbonate and the production method are described in JP-A-7-150166. The high molecular weight succinic anhydride substituted with an alkenyl group or an alkyl group is a polybutene having a molecular weight (in the present specification, meaning a number average molecular weight) of 1000 to 2700, preferably 1900 to 2700. Desirably, it is obtained by reaction with maleic anhydride.

The above-mentioned boron-containing alkenyl or alkyl succinimide compound is an alkenyl or alkyl succinimide compound containing a boron atom in the molecule in a bonded state, and is also a known ashless dispersant, and has a high molecular weight. Alkenyl- or alkyl-substituted succinic anhydrides with a polyalkylenepolyamine containing on average 4 to 10 (preferably 5 to 7) nitrogen atoms per molecule, and the reaction product It can be produced by performing a post-reaction treatment with boric acid or a boric acid derivative. The boron content of the boron-containing alkenyl or alkyl succinimide compound is preferably in the range of 0.1 to 5% by weight, particularly preferably in the range of 0.2 to 2% by weight. The high molecular weight succinic anhydride substituted with an alkenyl group or an alkyl group has a molecular weight (in the present specification, a number average molecular weight) of 1000 to 2700.
Of polybutene and maleic anhydride.

In the lubricating oil composition of the present invention, the total content of the alkenyl or alkyl succinimide compound and the boron-containing alkenyl or alkyl succinimide compound that has been treated with the cyclic carbonate is as follows:
It is preferably in the range of 0 to 15% by weight, especially 2.
It is desirably in the range of 0 to 10.0% by weight. It is preferable that the alkenyl or alkyl succinimide compound treated with the cyclic carbonate and the boron-containing alkenyl or alkyl succinimide compound are contained in a weight ratio of 2: 8 to 8: 2, particularly 7: 3. It is desirable that they are contained in a ratio of ~ 3: 7.

The lubricating oil composition of the present invention may further contain a dispersant other than the above-mentioned ashless dispersants, for example, succinic ester dispersants and benzylamine dispersants.

It is desirable that the lubricating oil composition of the present invention further comprises a metal-containing detergent in an amount of not more than 20% by weight, preferably in an amount of 0.5 to 20% by weight. Examples of such metal-containing detergents include metal phenates, metal sulfonates, and the like. The metal detergent may be an overbased number type having a total base number (TBN) of 150 to 300 or more, or may be a neutral type.

The metal phenate is an alkali metal salt or alkaline earth metal salt of a sulfide of an alkylphenol containing an alkyl group having about 8 to 30 carbon atoms (average number of carbon atoms). Examples of alkali metal and alkaline earth metal salts include lithium, sodium, calcium, magnesium, and barium salts. In particular, sulfurized calcium phenate is preferred.
The metal sulfonate is a sulfonate of a mineral oil having a molecular weight of about 400 to 6000, or an alkali metal or alkaline earth metal salt of a sulfonate of an aromatic compound having an alkyl group. Examples of alkali metal salts and alkaline earth metal salts are also lithium salts, sodium salts,
Mention may be made of calcium, magnesium and barium salts. The metal phenate and the metal sulfonate may be used alone or in combination. Further, other metal-containing detergents such as alkaline earth metal salicylate, alkaline earth metal phosphonate, and alkaline earth metal naphthenate may be used in combination with metal phenate and metal sulfonate. In addition, these metal-containing detergents can be used alone.

It is desirable that the lubricating oil composition of the present invention further contains zinc dialkyldithiophosphate (Zn-DTP) in an amount of 3.0% by weight or less, particularly 0.1 to 3.0% by weight. In addition, the zinc dialkyldithiophosphate is an alkyl group having 3 to 18 carbon atoms or a carbon atom having 3 to 1 carbon atoms.
It is desirable to have an alkylaryl group containing 8 alkyl groups. Particularly preferred are an alkyl group derived from a secondary alcohol having 3 to 18 carbon atoms, or a primary alcohol having 3 to 18 carbon atoms and a primary alcohol having 3 to 18 carbon atoms, which are particularly effective in suppressing wear. Is a zinc dialkyldithiophosphate containing an alkyl group derived from a mixture with a secondary alcohol.

The lubricating oil composition of the present invention further comprises a molybdenum-containing compound in an amount of 5.0% by weight or less (particularly,
(Amount in the range of 5.0% by weight). The molybdenum-containing compound mainly functions as a friction modifier in the lubricating oil composition and contributes to improvement in cleanliness at high temperatures. The content of the molybdenum-containing compound in the lubricating oil composition is 10 to 250 in terms of molybdenum metal content.
Desirably, it is in the range of 0 ppm. Examples of molybdenum-containing compounds include sulfur-containing molybdenum complexes of succinimide (described in Japanese Patent Publication No. 3-22438), oxymolybdenum dithiocarbamate, oxymolybdenum dithiophosphate, amine molybdenum complex compounds, oxymolybdenum dielate amide And oxymolybdenum monoglycerides.

The lubricating oil composition of the present invention may further contain a phenolic or amine-based antioxidant in an amount within 5.0% by weight (preferably 0.02 to 5.0% by weight, particularly 0.1 to 5.0% by weight).
(Amount in the range of 3% by weight). Examples of phenolic antioxidants include 2,6-di-t-butyl-p-cresol, 4,4′-methylenebis (2,6
-Di-t-butylphenol), 4,4'-methylenebis (6-t-butyl-o-cresol), 4,4'-thiobis (2-methyl-6-t-butylphenol),
2,2-thio-diethylenebis [3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate], and hindered phenols such as isooctyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate. Examples of amine-based antioxidants include mixed alkyl diphenylamines having 4 to 9 carbon atoms, p, p'-dioctyldiphenylamine, phenyl-α-naphthylamine, alkylated-α-naphthylamine, and alkylated-phenyl- Examples thereof include diarylamines such as α-naphthylamine. Although the phenolic antioxidant and the amine antioxidant can be used alone, they can be used in combination if desired.

It is desirable that the lubricating oil composition of the present invention further contains a viscosity index improver in an amount of not more than 20% by weight (preferably in the range of 1 to 20% by weight). Examples of the viscosity index improver include high molecular compounds such as polyalkyl methacrylate, ethylene-propylene copolymer, styrene-butadiene copolymer, and polyisoprene. Alternatively, a dispersion-type viscosity index improver or a multifunctional clay index improver obtained by imparting dispersibility to these polymer compounds can be used. These viscosity index improvers can be used alone or in combination of two or more.

[0028] The lubricating oil composition of the present invention may further contain various auxiliary additives. Examples of such auxiliary additives include zinc dithiocarbamate, methylenebis (dibutyldithiocarbamate), oil-soluble copper compounds, sulfur-based compounds (eg, sulfurized olefins, sulfurized esters, antioxidants or antiwear agents). Polysulfide), a phosphoric ester, a phosphite, an organic amide compound (eg, oleylamide), and the like. Also, a benzotriazole-based compound or a thiadiazole-based compound that acts as a metal deactivator can be added. Also, polyoxyethylene alkyl phenyl ether acting as a rust inhibitor or demulsifier,
A polyoxyalkylene nonionic surfactant such as a copolymer of ethylene oxide and propylene oxide can also be added. In addition, various amines, amides, amine salts, and derivatives thereof, which act as friction modifiers, or fatty acid esters of polyhydric alcohols, or their derivatives can also be added. Furthermore, various compounds acting as antifoaming agents or pour point depressants can also be added. These auxiliary additives are preferably used in an amount of 3% by weight or less (particularly, in the range of 0.001 to 3% by weight) based on the lubricating oil composition.

[0029]

【Example】

[Example 1] (1) Production of a lubricating oil composition A lubricating oil composition according to the present invention (sample oil numbers 1 to 4) having a formulation shown in Table 1 below and a lubricating oil composition for comparison (sample oil number) 5-8) were produced. These lubricating oil compositions were adjusted to show a viscosity grade of 10W30 (SAE viscosity grade) by adding a viscosity index improver.

(2) Additives and Base Oil Details of the additives and base oils shown in Table 1 are as follows. Dispersant A: succinimide dispersant (nitrogen content: 1.4)
% By weight, obtained by reacting polybutene having a number average molecular weight of about 900 with maleic anhydride and a polyalkylene polyamine having an average number of nitrogen atoms of 5 (per molecule)) Dispersant B: Boron-containing succinimide-based dispersant (nitrogen content: 1.5% by weight, boron content: 0.5% by weight, prepared from polybutene having a number average molecular weight of about 1300 and maleic anhydride; 6.5 (per molecule) reacted with polyalkylene polyamine, and then the resulting succinimide was treated with boric acid; produced according to Example 8 of JP-A-7-150166.) Dispersant C : Ethylene carbonate reaction-treated succinimide dispersant (nitrogen content: 0.7% by weight, number average molecular weight: about 2200)
Of polybutene and maleic anhydride, which is reacted with a polyalkylene polyamine having an average number of atoms of 6.5 (per molecule), and the resulting succinimide is treated with ethylene carbonate; Kaihei 7-15016
No. 6, published in accordance with Example 17)

Detergent A: Sulfurized calcium phenate (T
BN: 250 mg KOH / g) Detergent B: calcium sulfonate (TBN: 20 mg)
-KOH / g) Zn-DTP: zinc dialkyldithiophosphate (phosphorus content: 7.2% by weight, using a secondary alcohol having 3 to 8 carbon atoms as a raw material) Antioxidant A: phenolic compound [4 4'-methylenebis (2,6-di-t-butylphenol)] Antioxidant B: amine compound [alkylated diphenylamine]

Mo compound: Oxymolybdenum-succinimide complex compound containing sulfur (molybdenum content:
VII: Viscosity index improver (dispersed ethylene-propylene copolymer) Others: small amount of rust inhibitor, friction modifier, antiwear agent, metal deactivator, demulsifier, defoamer Auxiliary component consisting of agent and pour point depressant Base oil: 150 neutral oil (viscosity index: 100)

(3) Test method 1) Hot tube test (KES-07-803): Evaluation of cleanliness at high temperature A glass tube having an inner diameter of 2 mm was set vertically on a heater block, and 0.31 cc / hour of sample oil was applied. And air 10
Each is sent from the lower part of the glass tube at a rate of cc / min. This operation is continued for 16 hours while maintaining the temperature of the heater section at 290 ° C. The deposit (sediment) adhering to the inside of the glass tube after the test is evaluated on a scale of 10 out of 10 (10 points mean that no deposit is deposited).

2) Gasoline Engine Test-Cleanliness Test (JASO-M331-91): Evaluation of Cleanliness at Medium and Low Temperatures
Start high-speed cycle operation and continue this operation for 300 hours (JASO, a test method specified by the Japan Automobile Engineers Association).
-M331-91). Then, the sludge adhering to the low cover was evaluated on a scale of 1 to 10 (10 points).
The dots indicate the absence of sludge.)

The results obtained in each test are shown in Table 1.

Table 1 添加 Additive / lubricating oil composition Sample oil number Base oil 1 2 3 4 5 6 7 8 ────────────────────────────────── ── Dispersant A----------------2.5 2.5 Dispersant B 1.5 1.5 2.5 2.5 2.5---4.5 --- 2.0 Dispersant C 3.0 3.0 2.0 2.0 4.5 --- 2.0 --- Detergent A 1.8 1.8 1.8 1.8 1.8. 8 1.8 1.8 1.8 Detergent B 1.7 1.7 1.7 1.7 1.7 1.7 1.7 1.7 1.7 Zn-DTP 1.3 1.3 1.3 1.3 1 1.3 1.3 1.3 1.3 1.3 Antioxidant A 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Acid Inhibitor B 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Mo compound---0.2---0.2--------- --- VII 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5 Others 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 ──────────────────────────────────── Base oil 82.8 82.6 82.8 82.6 82.8 82.8 82.8 82.8 ─ ─────────────────────────────────── Hot tube test 6.0 7.5 7.0 8. 0 5.0 7.0 5.5 6.5 (Score 10 is best) ─────────────────────────────── ───── Rocker cover Sludge 9.3 9.3 9.2 9.2 9.4 8.3 8.2 8.2 7.9 (Review) 10 is the best) ────────────────────────────────────

From the results shown in the above table, it can be seen that the lubricant composition of the present invention containing a combination of an alkenyl or alkyl succinimide compound treated with a cyclic carbonate and a alkenyl or alkyl succinimide compound containing boron has a low It can be seen that the cleanliness is high (this is especially important for use in gasoline engines) and that the cleanliness at high temperatures is also high (this is especially important for use in diesel engines). Further, the addition of the molybdenum-containing compound further improves the cleanliness at high temperatures.

[0038]

EFFECT OF THE INVENTION The lubricant composition of the present invention to which a combination of an alkenyl or alkyl succinimide compound treated with a cyclic carbonate and a boron-containing alkenyl or alkyl succinimide compound are added has high cleanliness at medium to low temperatures (this Is particularly important for use in gasoline engines) and has high cleanliness at high temperatures (which is especially important for use in diesel engines). The addition of the molybdenum-containing compound further improves the cleanliness at high temperatures.

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI C10M 129: 84) (C10M 163/00 159: 12 137: 10 139: 00 129: 10 133: 12) C10N 10:04 10:12 20: 04 30:02 30:04 30:06 30:10 40:25 60:14 70:00

Claims (14)

[Claims] An alkenyl or alkyl succinimide compound treated with a cyclic carbonate is dissolved or dispersed in a base oil in an amount of 0.5 to 15% by weight and a boron-containing alkenyl or alkyl succinimide compound in an amount of 0.5 to 15% by weight. A lubricating oil composition comprising: 2. The lubricating oil composition according to claim 1, further comprising 0.5 to 20% by weight of a metal-containing detergent. 3. The lubricating oil composition according to claim 1, further comprising 0.1 to 3.0% by weight of a zinc dialkyldithiophosphate. 4. The lubricating oil composition according to claim 1, further comprising 0.02 to 5.0% by weight of a molybdenum compound. 5. The lubricating oil composition according to claim 1, further comprising a molybdenum compound in an amount of 10 to 2500 ppm in terms of molybdenum atomic weight. 6. An antioxidant selected from the group consisting of phenolic compounds and amine compounds in an amount of 0.1 to
The lubricating oil composition according to any one of claims 1 to 5, comprising 5.0% by weight. 7. The composition of claim 1, further comprising 1 to 20% by weight of a viscosity index improver.
The lubricating oil composition according to any one of claims 1 to 6, comprising: 8. An alkenyl or alkyl succinimide compound which has been treated with a cyclic carbonate, comprises a succinic anhydride substituted with an alkenyl group or an alkyl group and a polyalkylene polyamine containing an average of 4 to 10 nitrogen atoms per molecule. The lubricating oil composition according to claim 1, wherein the lubricating oil composition is obtained by the reaction of (1) and further subjected to a post-reaction treatment with a cyclic carbonate compound. 9. An alkenyl or alkyl succinimide compound treated with a cyclic carbonate, wherein the alkenyl or alkyl has an average molecular weight of 1,000 to 27.
The lubricating oil composition according to claim 1, wherein the lubricating oil composition is derived from polybutene No. 00. 10. An alkenyl or alkyl succinimide compound treated with a cyclic carbonate, wherein the alkenyl or alkyl has an average molecular weight of 1900 to 27.
The lubricating oil composition according to claim 1, wherein the lubricating oil composition is derived from polybutene No. 00. 11. The lubricating oil composition according to claim 1, wherein the alkenyl or alkyl of the boron-containing alkenyl or alkyl succinimide compound is derived from polybutene having an average molecular weight of 1,000 to 2,700. 12. The lubricating oil composition according to claim 1, wherein the total content of the alkenyl or alkyl succinimide compound and the boron-containing alkenyl or alkyl succinimide compound reacted with the cyclic carbonate is 1.0 to 15% by weight. 13. The method according to claim 1, wherein the alkenyl or alkyl succinimide compound treated with the cyclic carbonate and the boron-containing alkenyl or alkyl succinimide compound are contained in a weight ratio of 2: 8 to 8: 2. Lubricating oil composition. 14. The lubricating oil composition according to claim 1, which is for an internal combustion engine.