WO2017094383A1

WO2017094383A1 - Lubricating oil composition for internal combustion engine

Info

Publication number: WO2017094383A1
Application number: PCT/JP2016/080979
Authority: WO
Inventors: 林　誠; 吉田　悟
Original assignee: Ｊｘエネルギー株式会社
Priority date: 2015-12-01
Filing date: 2016-10-19
Publication date: 2017-06-08
Also published as: JP6736037B2; US20180320103A1; JPWO2017094383A1; CN108291169A

Abstract

The present invention provides a lubricating oil composition for internal combustion engines which comprises a lube base oil, an ash-free friction modifier, and a boron-containing dispersant.

Description

Lubricating oil composition for internal combustion engines

The present invention relates to a lubricating oil composition for an internal combustion engine.

In recent years, lubricating oil (engine oil) used for internal combustion engines such as automobile engines has been required to improve fuel efficiency in order to reduce CO ₂ emissions from automobiles. As a method for improving the fuel economy of engine oil, there is a reduction in the viscosity of the oil. However, if the viscosity is excessively reduced, the engine may be worn. Therefore, a method for improving fuel economy by adding a friction modifier has been studied instead.

For example, Patent Document 1 discloses a diesel engine oil composition containing a predetermined mineral oil base oil and various additives such as a molybdenum dithiocarbamate friction modifier for the purpose of improving fuel efficiency by reducing friction. Yes.

JP 2002-220597 A

An object of the present invention is to provide a lubricating oil composition for an internal combustion engine, which is excellent in fuel saving and corrosion resistance against copper and lead.

The present invention provides a lubricating oil composition for an internal combustion engine comprising a lubricating base oil, an ashless friction modifier, and a boron-containing dispersant.

The lubricating oil composition preferably further contains an overbased organic acid metal salt that is overbased with calcium borate.

Lubricating oil composition is suitably used as diesel engine oil.

According to the present invention, it is possible to provide a lubricating oil composition for an internal combustion engine which is excellent in fuel saving and corrosion resistance against copper and lead.

The lubricating oil composition according to this embodiment comprises a lubricating base oil, (A) an ashless friction modifier (hereinafter also referred to as “(A) component”), and (B) a boron-containing dispersant (hereinafter referred to as “(B ) Component ”)). The lubricating oil composition according to this embodiment is suitable as a lubricating oil composition for internal combustion engines.

Lubricating oil base oil is not particularly limited, and may be a base oil used for ordinary lubricating oil. Specifically, the lubricant base oil includes a mineral base oil, a synthetic base oil, or a mixture of both.

As mineral base oils, lubricating oil fractions obtained by subjecting crude oil to atmospheric distillation and reduced pressure distillation are subjected to solvent deburring, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid Examples include paraffinic and naphthenic mineral oil base oils, normal paraffins, isoparaffins, and the like, which are purified by combining purification treatments such as washing and clay treatment alone or in combination of two or more. These mineral oil base oils may be used singly or in combination of two or more at any ratio.

Preferred mineral 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-distilled distilled oil (WVGO) of atmospheric distillation residue oil of paraffin-based crude oil and / or mixed-base crude oil )
(3) Wax obtained by lubricating oil dewaxing step and / or Fischer-Tropsch wax produced by GTL process or the like (4) One or more mixed oils selected from the above (1) to (3) Mild hydrocracking oil (MHC)
(5) Mixed oil of two or more oils selected from the above (1) to (4) (6) Detachment of (1), (2), (3), (4) or (5) Oil (DAO)
(7) 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

Here, the normal refining method is not particularly limited, and a refining method used in base oil production can be arbitrarily employed. Examples of normal purification methods include the following purification methods.
(A) Hydrorefining, such as hydrocracking, hydrofinishing, etc. (b) Solvent refining, such as furfural solvent extraction (c) Dewaxing, such as solvent dewaxing, catalytic dewaxing, etc. (d) White clay with acid clay, activated clay, etc. Purification (e) Chemical (acid or alkali) purification such as sulfuric acid washing and caustic soda washing These purification methods can be used singly or in combination of two or more and in any order.

Synthetic base oils include poly α-olefins or hydrides thereof, isobutene oligomers or hydrides thereof, isoparaffins, alkylbenzenes, alkylnaphthalenes, diesters (ditridecylglutarate, di-2-ethylhexyl adipate, di-2-ethylhexyl azease). Rate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, etc.), polyol ester (trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, etc.), Examples thereof include polyoxyalkylene glycol, dialkyl diphenyl ether, polyphenyl ether and the like. Among them, poly α-olefin is preferable. Examples of the poly α-olefin include oligomers or co-oligomers (1-octene oligomers, decene oligomers, ethylene-propylene co-oligomers, etc.) of α-olefins having 2 to 32 carbon atoms, preferably 6 to 16 carbon atoms, and their A hydride is mentioned. These synthetic base oils may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios.

The kinematic viscosity at 40 ° C. of the lubricating base oil is preferably 13.0 mm ² / s or more, more preferably from the viewpoint of sufficient oil film formation, excellent lubricity, and smaller evaporation loss under high temperature conditions. 15.0 mm ² / s or more, further preferably 17.0 mm ² / s or more. The kinematic viscosity at 40 ° C. of the lubricating base oil is preferably 42.0 mm ² / s or less, more preferably 40.0 mm ² / s or less, from the viewpoint of improving low-temperature viscosity characteristics and further improving fuel economy. Preferably it is 38.0 mm < ² > / s or less.

The kinematic viscosity at 100 ° C. of the lubricating base oil is preferably 2.0 mm ² / s or more, more preferably from the viewpoint of sufficient oil film formation, excellent lubricity, and smaller evaporation loss under high temperature conditions. 3.0 mm ² / s or more, further preferably 3.5 mm ² / s or more. The kinematic viscosity at 100 ° C. of the lubricating base oil is preferably 8.0 mm ² / s or less, more preferably 7.0 mm ² / s or less, and more preferably 7.0 mm ² / s or less, from the viewpoint of improving low temperature viscosity characteristics and further improving fuel economy. Preferably it is 6.0 mm < ² > / s or less.

The viscosity index of the lubricating base oil is preferably 100 or more, more preferably 110 or more, from the viewpoint of improving viscosity-temperature characteristics, thermal / oxidation stability, and volatilization prevention properties, and further reducing the friction coefficient. Preferably it is 120 or more. The viscosity index of the lubricating base oil is preferably 180 or less, more preferably 170 or less, and still more preferably 160 or less, from the viewpoint of excellent low-temperature viscosity characteristics.

The kinematic viscosity and the viscosity index in the present invention mean the kinematic viscosity and the viscosity index measured according to JIS K2283: 2000, respectively.

The content of the lubricating base oil may be, for example, 50% by mass or more, 70% by mass or more, or 90% by mass or more based on the total amount of the lubricating oil composition.

(A) Examples of ashless friction modifiers include nitrogen-containing ashless friction modifiers and oxygen-containing ashless friction modifiers, with nitrogen-containing ashless friction modifiers being preferred. Specifically, examples of the component (A) include compounds such as amines, amides, imides, fatty acid esters, fatty acids, aliphatic alcohols, and aliphatic ethers. These compounds include, for example, a hydrocarbon group having 6 to 30 carbon atoms, preferably an alkyl group or alkenyl group having 6 to 30 carbon atoms, more preferably a linear alkyl group or linear alkenyl group having 6 to 30 carbon atoms. Have at least one. The component (A) is preferably at least one selected from amines, amides and fatty acid esters, more preferably at least one selected from amines and amides, from the viewpoint of further improving fuel economy.

Examples of the amine include linear or branched aliphatic monoamines or aliphatic polyamines, and alkylene oxide adducts thereof. These amines may have, for example, 6 to 30 carbon atoms. The amine is preferably an amine represented by the following formula (1).
R ¹ —NH ₂ (1)
[In the formula (1), R ¹ is a hydrocarbon group having 6 to 30 carbon atoms, preferably an alkyl group or alkenyl group having 6 to 30 carbon atoms, more preferably a straight chain having 6 to 30 carbon atoms. An alkyl group or a linear alkenyl group. ]
Specific examples of the amine represented by the formula (1) include oleylamine and stearylamine.

Examples of amides include amides of linear or branched fatty acids and aliphatic monoamines or aliphatic polyamines. These amides may have, for example, 7 to 31 carbon atoms. The amide is preferably an amide represented by the following formula (2).
R ¹ —C (═O) —NH ₂ (2)
[In formula (2), ^{R 1} represents the same definition as ^{R 1} in Formula (1). ]
Specific examples of the amide represented by the formula (2) include oleylamide and acrylamide.

Examples of fatty acid esters include esters of linear or branched fatty acids and aliphatic monohydric alcohols or aliphatic polyhydric alcohols. The fatty acid may be a saturated fatty acid or an unsaturated fatty acid. These fatty acid esters may have, for example, 7 to 31 carbon atoms. The fatty acid ester is preferably an ester of a fatty acid and an aliphatic polyhydric alcohol, more preferably an ester of a linear fatty acid and an aliphatic polyhydric alcohol, and even more preferably a linear unsaturated fatty acid. And an aliphatic polyhydric alcohol. These esters of aliphatic polyhydric alcohols may be complete esters or partial esters, and are preferably partial esters. Specific examples of esters of these aliphatic polyhydric alcohols include glycerin monooleate.

The content of the component (A) is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, still more preferably 0, based on the total amount of the lubricating oil composition, from the viewpoint of further improving fuel economy. .3% by mass or more. The content of the component (A) is preferably 0.8% by mass or less, more preferably 0.7% by mass or less, still more preferably 0, based on the total amount of the lubricating oil composition, from the viewpoint of excellent long-term storage stability. .6% by mass or less. The content of the component (A) is preferably 0.1 to 0.8% by mass, 0.1 to 0.8% by weight based on the total amount of the lubricating oil composition from the viewpoint of achieving both fuel saving and long-term storage stability. 0.7%, 0.1-0.6%, 0.2-0.8%, 0.2-0.7%, 0.2-0.6%, 0.3- 0.8 mass%, 0.3-0.7 mass%, or 0.3-0.6 mass%.

(B) As the boron-containing dispersant, nitrogen-containing compounds such as succinimide, benzylamine, polyamine, Mannich base having an alkenyl group or alkyl group derived from polyolefin, and boric acid to these nitrogen-containing compounds, Derivatives obtained by acting boron compounds such as borates are exemplified. Among these, a derivative obtained by allowing a boron compound such as boric acid or borate to act on a nitrogen-containing compound is preferable. The alkenyl group or alkyl group may be linear or branched, and is branched from an olefin oligomer such as a propylene group, 1-butene group, isobutylene group, or a co-oligomer of ethylene and propylene. It may be an alkyl group or a branched alkenyl group.

Specific examples of the component (B) include so-called monotype succinimide represented by the following formula (3) or so-called bis-type succinimide represented by the following formula (4): boric acid, boric acid Examples thereof include modified succinimides modified with a boron compound such as a salt.

In the formula (3), R ² represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, and preferably represents an alkyl group or alkenyl group having 60 to 350 carbon atoms. R ² is preferably a polybutenyl group. m represents an integer of 1 to 5, preferably an integer of 2 to 4.

In the formula (4), R ³ and R ⁴ may be the same or different and each represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably an alkyl group or alkenyl group having 60 to 350 carbon atoms. Represents. R ³ and R ⁴ are preferably each a polybutenyl group. n represents an integer of 0 to 4, preferably an integer of 1 to 3.

The content of the component (B) is preferably 90 mass ppm or more, more preferably 100 mass ppm or more, and more preferably 100 mass ppm or more, in terms of boron element, based on the total amount of the lubricating oil composition, from the viewpoint of further excellent corrosion resistance to lead. Preferably it is 110 mass ppm or more. The content of component (B) is preferably 180 mass ppm or less, more preferably 170 mass ppm or less, more preferably 170 mass ppm or less, in terms of boron element, based on the total amount of the lubricating oil composition, from the viewpoint of further improving fuel economy. It is 160 mass ppm or less. The content of the component (B) is preferably 90 to 180 masses in terms of boron element, based on the total amount of the lubricating oil composition, from the viewpoint of achieving both high levels of corrosion prevention and fuel saving for lead. ppm, 90-170 ppm, 90-160 ppm, 100-180 ppm, 100-170 ppm, 100-160 ppm, 110-180 ppm, 110-170 ppm, or 110-160 ppm It is. The content of component (B) (in terms of boron element) can be measured by ICP elemental analysis.

The lubricating oil composition preferably comprises (C) an overbased organic acid metal salt (hereinafter also referred to as “component (C)”) overbased with calcium borate, from the viewpoint of further superior corrosion resistance to lead. Furthermore, it contains. Examples of organic acid metal salts include alkaline earth metal sulfonates, alkaline earth metal salicylates, alkaline earth metal phenates, alkaline earth metal phosphonates, and the like. The alkaline earth metal may be magnesium, calcium or barium, preferably calcium. The component (C) can be obtained, for example, by reacting the above organic acid metal salt, calcium hydroxide or calcium oxide, and boric acid or anhydrous boric acid.

The base value of the component (C) is preferably 50 mgKOH / g or more, more preferably 100 mgKOH / g or more, and further preferably 150 mgKOH / g or more. The base number of component (C) is preferably 500 mgKOH / g or less, more preferably 400 mgKOH / g or less, and still more preferably 300 mgKOH / g or less. The base number in the present invention is 9. JIS K2501: 2003 9. The base number measured by the perchloric acid method.

The content of the component (C) is preferably 100 ppm by mass or more, more preferably 110 ppm by mass or more, more preferably 110 ppm by mass or more in terms of calcium element, based on the total amount of the lubricating oil composition, from the viewpoint of further excellent corrosion resistance to lead. Preferably it is 120 mass ppm or more. The content of the component (C) is preferably 350 mass ppm or less, more preferably 330 mass ppm or less, more preferably 330 mass ppm or less in terms of calcium element, based on the total amount of the lubricating oil composition, from the viewpoint of further excellent corrosion resistance to lead. Preferably it is 300 mass ppm or less. The content of the component (C) is preferably 100 to 350 ppm by mass, 100 to 330 ppm by mass, 100 to 330 ppm by mass, in terms of calcium element, based on the total amount of the lubricating oil composition, from the viewpoint of further excellent corrosion resistance to lead. -300 mass ppm, 110-350 mass ppm, 110-330 mass ppm, 110-300 mass ppm, 120-350 mass ppm, 120-330 mass ppm, or 120-300 mass ppm. The content of component (C) (calcium element equivalent) can be measured by ICP elemental analysis.

The lubricating oil composition may further contain other additives. Other additives include viscosity index improvers, antiwear agents, antioxidants, antifoaming agents, pour point depressants, corrosion inhibitors, rust inhibitors, demulsifiers, metal deactivators, and the like.

Examples of the viscosity index improver include a poly (meth) acrylate viscosity index improver, an olefin copolymer viscosity index improver, and a styrene-diene copolymer viscosity index improver. These viscosity index improvers may be either non-dispersed or dispersed, preferably non-dispersed. The viscosity index improver is preferably a poly (meth) acrylate viscosity index improver, more preferably a non-dispersed poly (meta), from the viewpoint of high viscosity index improving effect and excellent viscosity-temperature characteristics and low temperature viscosity characteristics. ) Acrylate viscosity index improver.

The pour point depressant may be, for example, poly (meth) acrylate, preferably poly (meth) acrylate having a weight average molecular weight of 10,000 to 300,000, more preferably 50,000 to 200,000.

Antiwear agents include phosphorous acid esters (phosphites), phosphoric acid esters, and phosphorus-based antiwear agents such as amine salts, metal salts, and derivatives thereof, disulfides, polysulfides, sulfurized olefins, sulfurized fats and oils, etc. And sulfur-based antiwear agents.

Examples of the antioxidant include ashless antioxidants such as phenols and amines, and metal antioxidants such as copper and molybdenum. Specifically, for example, phenol-based ashless antioxidants include 4,4′-methylenebis (2,6-di-tert-butylphenol), 4,4′-bis (2,6-di-tert- Examples of amine-based ashless antioxidants include phenyl-α-naphthylamine, alkylphenyl-α-naphthylamine, dialkyldiphenylamine, and diphenylamine.

As the defoaming agent, for example, 100,000 mm kinematic viscosity at 25 ° C. is 1000 mm ² / s or more ² / s or less silicone oil, alkenylsuccinic acid derivatives, esters of polyhydroxy aliphatic alcohols and long-chain fatty acids, methyl salicylate And esters of o-hydroxybenzyl alcohol and the like.

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

Examples of the rust preventive include alkenyl succinate, polyhydric alcohol ester, petroleum sulfonate, alkylbenzene sulfonate, dinonylnaphthalene sulfonate, and the like.

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 the metal deactivator include imidazoline, pyrimidine derivatives, benzotriazole or derivatives thereof.

The content of other additives may be 0.01 to 20% by mass based on the total amount of the lubricating oil composition.

The kinematic viscosity at 40 ° C. of the lubricating oil composition is preferably 31.0 mm ² / s or more, more preferably 33.0 mm ² / s or more, and further preferably 35.0 mm ² / s or more, from the viewpoint of excellent lubricity. It is. Kinematic viscosity at 40 ° C. of the lubricating oil composition, to ensure low-temperature viscosity required, from the viewpoint of further improving the fuel economy, preferably 75.0 mm ² / s or less, more preferably 72.0 mm ² / s or less More preferably, it is 70.0 mm ² / s or less.

Kinematic viscosity at 100 ° C. of the lubricating oil composition, from the viewpoint of excellent lubricity, preferably 5.0 mm ² / s or more, more preferably 7.0 mm ² / s or more, more preferably 8.0 mm ² / s or more It is. Kinematic viscosity at 100 ° C. of the lubricating oil composition, to ensure low-temperature viscosity required, from the viewpoint of further improving the fuel economy, preferably 14.0 mm ² / s or less, more preferably 13.0 mm ² / s or less More preferably, it is 12.0 mm ² / s or less.

The viscosity index of the lubricating oil composition is preferably 120 or more, more preferably 140 or more, from the viewpoint that viscosity-temperature characteristics, thermal / oxidation stability, and volatilization prevention properties are improved and the friction coefficient is further reduced. Preferably it is 150 or more. The viscosity index of the lubricating base oil is preferably 270 or less, more preferably 260 or less, and even more preferably 250 or less, from the viewpoint of excellent low-temperature viscosity characteristics.

The boron element content in the lubricating oil composition is preferably 180 ppm by mass or more, more preferably 190 ppm by mass or more, and still more preferably 200 ppm, based on the total amount of the lubricating oil composition, from the viewpoint of further excellent corrosion resistance to lead. It is mass ppm or more. The boron element content in the lubricating oil composition is preferably 440 mass ppm or less, more preferably 420 mass ppm or less, based on the total amount of the lubricating oil composition, from the viewpoint of further excellent corrosion prevention and fuel economy for lead. More preferably, it is 400 mass ppm or less. The boron element content can be measured by ICP elemental analysis.

The calcium element content in the lubricating oil composition is preferably 1800 ppm by mass or more, more preferably 1900 ppm by mass or more, and still more preferably 2000, based on the total amount of the lubricating oil composition, from the viewpoint of further excellent corrosion resistance to lead. It is mass ppm or more. The calcium element content in the lubricating oil composition is preferably 2700 mass ppm or less, more preferably 2600 mass ppm or less, and even more preferably 2500, based on the total amount of the lubricating oil composition, from the viewpoint of further superior corrosion resistance to lead. The mass is ppm or less. The calcium element content can be measured by ICP elemental analysis.

The lubricating oil composition according to this embodiment is suitably used as a lubricating oil composition for internal combustion engines. Examples of the internal combustion engine include a gasoline engine, a diesel engine, an oxygen-containing compound-containing engine, a gas engine, and the like. The lubricating oil composition according to this embodiment is particularly preferably used as a diesel engine oil.

Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to the examples.

Lubricating oil compositions having the compositions shown in Tables 1 and 2 were prepared using the base oils and additives shown below.
(Base oil)
Hydrorefined mineral oil (kinematic viscosity at 100 ° C .: 4.4 mm ² / s, viscosity index: 127)
(Additive)
A-1: glycerin monooleate A-2: oleylamine A-3: oleylamide a-1: molybdenum dithiocarbamate B-1: boric acid modified polybutenyl succinimide (weight average molecular weight of polybutenyl group: 7420, boron Element content: 0.5% by mass)
C-1: Calcium salicylate overbased with calcium borate (base number: 190 mgKOH / g, calcium element content: 6.8% by mass)
D-1: Additive package containing calcium salicylate, calcium phenate, dialkyldithiophosphoric acid, etc. (boron element content: 0.12 mass%, calcium element content: 1.5 mass%)
E-1: Styrene-diene copolymer

(Fuel saving)
For each of the lubricating oil compositions of Examples 1 to 8 and Comparative Example 1, fuel economy was evaluated by the friction coefficient by SRV test and the HTHS viscosity at 100 ° C. (ASTM D4683). The results are shown in Table 3.
Concerning the friction coefficient, “A” when the friction coefficient is 0.150 or less, “B” when the friction coefficient exceeds 0.150 and 0.155 or less, and “C” when the friction coefficient exceeds 0.155. ".
Regarding the HTHS viscosity at 100 ° C. (ASTM D4683), “A” when the HTHS viscosity at 100 ° C. is 6.5 or less, and “B” when the HTHS viscosity at 100 ° C. is more than 6.5 and 6.7 or less. The case where the HTHS viscosity at 100 ° C. exceeded 6.7 was evaluated as “C”. The HTHS viscosity at 150 ° C. in all examples and comparative examples was 2.9.
If both the friction coefficient and the HTHS viscosity at 100 ° C. are evaluated as A or B, it can be said that the fuel efficiency is excellent.

(Corrosion prevention against copper)
Each of the lubricating oil compositions of Examples 1 to 8 and Comparative Example 2 was evaluated for corrosion resistance against copper in accordance with a corrosion oxidation stability test (JIS K2503: 2010). However, the sample amount was 100 ml, the test temperature was 135 ° C., the test time was 168 hours, the air flow rate was 5 L / h, and the catalyst was copper, lead, and tin. The results are shown in Table 4. It can be said that the smaller the elution amount of copper (for example, 20 mass ppm or less), the better the corrosion resistance against copper.

(Corrosion prevention for lead)
Each of the lubricating oil compositions of Examples 1 to 8 was evaluated for corrosion resistance against lead in accordance with a corrosion oxidation stability test (JIS K2503: 2010). However, the sample amount was 100 ml, the test temperature was 135 ° C., the test time was 168 hours, the air flow rate was 5 L / h, and the catalyst was copper, lead, and tin. The results are shown in Table 5. It can be said that the smaller the elution amount of lead (for example, 150 ppm by mass or less), the better the corrosion resistance against lead.

Claims

Lubricating base oil,
An ashless friction modifier,
A boron-containing dispersant;
A lubricating oil composition for an internal combustion engine, comprising:
The lubricating oil composition for an internal combustion engine according to claim 1, further comprising an overbased organic acid metal salt overbased with calcium borate.
The lubricating oil composition for an internal combustion engine according to claim 1 or 2, which is used as a diesel engine oil.