JPH08337788A - Engine lubricating oil additive and engine lubricating oil composition - Google Patents

Abstract

PURPOSE: To obtain an engine lubricating oil additive comprising silane compounds, excellent in cleanliness in cleanliness of an engine piston and friction-reducing performance, capable of bringing the engine to have long life with reduced or no addition of a phosphor-based extreme pressure agent, etc., and useful for engines for land transportation and shipping. CONSTITUTION: This lubricating oil additive comprises silane compounds such as compounds of formula I [R is H, a 1-18C (branched) alkyl, a 2-18C (branched) alkenyl, a 6-18C aryl; R1 is a 6-50C (branched) alkyl, a 6-50C (branched) alknyl a 6-50C aryl, the alkyl can have N, O or S or can be substituted by OH, carboxy, an alkoxycarbonyl, an alkenoxycarbonyl or an aryloxycarbonyl], formula II and formula III, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil additive for engines for land and ships, and a lubricating oil composition for engines. More specifically, the present invention relates to an engine lubricating oil additive which has the effect of reducing the friction of engine oil and improves piston cleanliness, and an engine lubricating oil composition containing the same.

[0002]

2. Description of the Related Art In recent years, piston / cylinder type engines, from gasoline engines for land use, diesel engines for land use to ships and power generation, have high output, reduced fuel consumption,
Furthermore, there is a growing need for maintenance-free products, and engine oils are therefore required to have high functionality and long life.
Above all, there is a strong demand for reducing fuel consumption and extending the life of engine oil. In addition, exhaust gas regulations are combined with the problems of reducing the friction of engine oil and lowering the cleaning action around the piston. However, at present, the functions of the engine oil, such as the friction reducing effect and the cleaning effect, are significantly deteriorated in the combustion gas atmosphere.

Diesel engines are used in power generation, ships, trucks, etc., and use low-quality fuel containing a large amount of petroleum distillation residues. Since the low-quality fuel contains a large amount of sulfur compounds, the combustion gas contains a large amount of sulfur oxides and also contains a large amount of harmful substances such as nitrogen oxides.

These sulfur oxides and nitrogen oxides condense in the engine to form sulfuric acid and nitric acid, which accelerates the wear increase and the accumulation phenomenon of dirt components (sludge). That is, the formation of acidic substances such as sulfuric acid and nitric acid in the engine causes chemical corrosion of the energy transmitting parts, pistons and cylinders, causing serious troubles.

Therefore, engine oils are expected to have the effect of suppressing the corrosive action of such acidic substances. However, the mixing of acidic substances into engine oil accelerates the deterioration of the oil and makes the respective functions of the oil remarkable. It has been confirmed to date that it is lowered. In particular, since the function that is deteriorated by the mixing of the acidic substance is the friction reduction effect and the cleaning function of the oil, it is necessary to frequently change the oil or replenish the oil. If the oil is not replaced or replenished, oil deterioration products, combustion products, unburned products, mixed dirt (sludge) such as abrasion powder will accumulate around the piston / cylinder liner, and the piston sliding parts will become worn. Becomes even more intense. As a result, a normal compression ratio cannot be finally obtained, which adversely affects operation and traveling.

On the other hand, a gasoline engine uses a fuel (gasoline) with a higher degree of purification than a diesel engine, but due to exhaust gas regulations, EGR (Exhaust Gas Recircul)
ation) method is beginning to be adopted. Therefore, the inside of the engine is more likely to be affected by the combustion gas, the oxidative deterioration of the oil in the combustion gas atmosphere progresses, and the piston ring,
Problems such as increased friction (increased wear) of the valve train and bearing, and deterioration of cleanliness of the piston side wall occur.

For the production of acidic substances as described above, engine oils have conventionally used additives called metallic detergents in lubricating oils to neutralize the acidic substances produced in the engine. However, measures have been taken to reduce the oxidative deterioration of engine oil (Journal of Japan Petroleum Institute Vol.35, No.1, 1992).
Development of overbased sulfurized phenates and sulfurized salicylates).

That is, as described below, the metallic detergent is
It dissolves or disperses in a state of a carboxylate, sulfonate, alcoholate or carbonate of an alkaline earth metal in oil to neutralize an acidic substance mixed in oil.

However, since the metallic detergent contains metal, it has a high ash content and has a drawback that a large amount of residue is accumulated in the high temperature region from the combustion chamber to the side wall of the piston. Sulfates (alkaline earth metal salts) and nitrates (alkaline earth metal salts) formed by neutralization of acidic substances absorb water and adhere to the piston ring, piston groove and other peripheral parts. as a result,
Scratches are formed on the friction surface, resulting in increased wear and seizure. Further, the sulfates and nitrates that have absorbed water tend to agglomerate the soot, which is an unburned substance, at high temperature, leaving the problem of facilitating the formation of soot stains.

That is, the combustion gas accelerates the performance of the engine oil, in particular, the increase in wear and the decrease in the cleansing dispersion effect. In addition, in engine oil, Japanese Patent Laid-Open No. 6-
No. 240282 (amine salt-based antiwear agent for acidic phosphoric acid ester), JP-A-6-240283 (vegetable triglyceride-based antiwear agent), and JP-A-6-271.
As disclosed in Japanese Patent No. 885 (molybdenum-based antiwear agent), phosphorus-based extreme pressure agents and ester-based oiliness improvers are used as friction reducing agents, but these additives are not chemically adsorbed or physically adsorbed on the friction part. And shows a friction reducing effect. As these additives, for example, alkyl zinc dithiophosphate, alkyl phosphoric acid ester, alkyl thiophosphoric acid ester, glycerin ester, and pentaerythritol ester are mainstream. However, these compounds easily hydrolyze in the atmosphere of exhaust gas, and the initial normal friction reducing effect cannot be expected for a long time.

[0011]

From the above, an engine lubricating oil additive and lubricating oil composition having satisfactory performance capable of coping with environmental deterioration in the engine due to "use of low quality fuel" and "exhaust gas regulation" It is the current situation that has not been obtained yet.

Accordingly, the present invention provides an engine lubricating oil additive which has the effect of reducing the friction of a piston / cylinder type engine oil and improves cleanliness, and an engine lubricating oil composition containing the same. It is intended.

[0013]

Under the above circumstances, the inventors of the present invention have made extensive studies as to the formation of stains and friction reducing agents on the periphery of pistons and cylinder liners due to deterioration of engine oil and mixing of acidic substances. It was found that the addition of the silane compound dramatically improved the effect of dispersing the dirt component (sludge) in the oil and also had the effect of reducing friction. As a result, it is possible to reduce the concentration of metal-based detergents and ashless dispersants that have been used in the past, reduce the concentration of friction reducing agents, and even to add no additives to improve engine oil performance. The present invention has been found to be useful and the present invention has been completed.

That is, the gist of the present invention is that (1) an engine lubricating oil additive comprising a silane compound and (2) a silane compound are represented by the following general formulas (a), (b) and (c). The lubricating oil additive for engines according to (1) above, which is one or more selected from the group consisting of compounds.

[0015]

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(In the formula, R represents a hydrogen atom, a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkenyl group having 2 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms. R ₁ represents a linear or branched alkyl group having 6 to 50 carbon atoms, a linear or branched alkenyl group having 6 to 50 carbon atoms, or an aryl group having 6 to 50 carbon atoms,
Further, the alkyl group has a nitrogen atom, an oxygen atom or a sulfur atom, or may be substituted with a hydroxy group, a carboxy group, an alkoxycarbonyl group, an alkenoxycarbonyl group or an aryloxycarbonyl group. (3) A lubricating oil composition for engines, comprising 0.05 to 10% by weight of the lubricating oil additive according to (1) or (2), (4) in a base oil (A), (1). Or (2)
The lubricating oil composition for engines prepared by blending the lubricating oil additive described above and (B) a metal-based detergent, (5) further blending (C) extreme pressure lubricant and (D) ashless dispersant (4) 0.05 to 10% by weight of the lubricating oil composition according to (1) or (2) above, and (B) the lubricating oil composition for engine according to (4) above, and (6) the base oil. ) 0.5 to 50% by weight of metal-based detergent and 0.0 of (C) extreme pressure lubricant.
The engine lubricating oil composition according to (5) above, which comprises 5 to 5% by weight and (D) an ashless dispersant in an amount of 0.1 to 10% by weight.

The engine lubricating oil additive of the present invention comprises a silane compound. Examples of the silane compound include the following general formulas (a), (b) and (c).
One or more kinds selected from the group consisting of compounds represented by are preferred examples.

[0018]

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R in the general formulas (a), (b) and (c)
Represents a hydrogen atom, a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkenyl group having 2 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms. Above all, R ₁ Si is formed by hydrolysis of a silane compound described later.
From the viewpoint of easily changing to (OH) ₃ structure, quickly dispersing, and exhibiting a friction reducing effect, R has 1 or 2 carbon atoms.
Are preferred.

Examples of the linear or branched alkyl group having 1 to 18 carbon atoms represented by R include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, Tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, 1-methylethyl, 1-methylpropyl, 1-methylpentyl, 1-methylhexyl, 2-ethylhexyl, 3,5,5-trimethylhexyl, isodecyl, 1-methylundecyl , Isotridecyl, 1-ethyldecyl, 2-heptylundecyl, 8
-Methylheptadecyl, 12-methylheptadecyl group and the like are mentioned, and as the linear or branched alkenyl group having 2 to 18 carbon atoms, vinyl, allyl, 2-propenyl,
1-butenyl, 1-hexenyl, 1-octenyl, 1-
Decenyl, 1-dodecenyl, 1-tetradecenyl, 1-
Hexadecenyl, 9-octadecenyl, 1-methylvinyl, 2-methyl-1-propenyl, 1-methyl-1-propenyl, 1-methyl-1-butenyl, 1-ethyl-1.
-Butenyl group and the like, and examples of the aryl group having 6 to 18 carbon atoms include phenyl, methylphenyl, dimethylphenyl, trimethylphenyl, ethylphenyl, diethylphenyl, triethylphenyl, ethenylphenyl, propylphenyl, isopropylphenyl and butyl. Examples thereof include phenyl, dibutylphenyl, isobutylphenyl, hexylphenyl, octylphenyl, nonylphenyl, decylphenyl, dihexylphenyl, dodecylphenyl and naphthyl groups.

R in the general formulas (a), (b) and (c)
₁ represents a linear or branched alkyl group having 6 to 50 carbon atoms, a linear or branched alkenyl group having 6 to 50 carbon atoms, or an aryl group having 6 to 50 carbon atoms, and the alkyl group is a nitrogen atom or an oxygen atom. Alternatively, it may have a sulfur atom, or may be substituted with a hydroxy group, a carboxy group, an alkoxycarbonyl group, an alkenoxycarbonyl group, or an aryloxycarbonyl group. Above all, carbon number 6
-24 are preferable. More preferably 10 to 22
Is. If the number of these hydrocarbon groups is less than 6, the solubility in oil will be poor, and if it exceeds 50, the cost will be high and it will be impractical.

The linear or branched alkyl group having 6 to 50 carbon atoms represented by R ₁ includes those having 6 to 18 carbon atoms among the alkyl groups listed for R, and further nonadecyl,
Eicosyl, Hen Eicosyl, Docosyl, Tricosyl,
Tetracosyl, hexacocyl, octacocyl, triacontyl, tetracontyl, pentacontyl, 1-methylnonadecyl, 2-ethyleicosyl, 1-ethyldocosyl, 1-methyltricosyl, 1,3,5-trimethylhexadecyl, 1,3,5,7 , 9-Pentamethylhexacosyl, 1,3,5,7,9,11-hexamethyltriacontyl, 1,3,5,7,9,11,13-heptamethyltetracontyl, 1,4 , 7,10,13-pentaethyltetracontyl group and the like, and has 6 to 5 carbon atoms.
Examples of the straight-chain or branched alkenyl group of 0 include those having 6 to 18 carbon atoms among the alkenyl groups listed for R, nonadecenyl, icosenyl, henicosenyl, docosenyl, tricosenyl, tetracosenyl, hexacosenyl,
Octacocenyl, triacontenyl, tetracontenyl, pentacontenyl, 1-methylnonadecenyl, 2-
Ethylicosenyl, 1-ethyldocosenyl, 1-methyltricosenyl, 1,3,5-trimethylhexadecenyl, 1,3,5,7,9-pentamethylhexacosenyl, 1,3,5,7,9 , 11-hexameltriacontenyl, 1,3,5,7,9,11,13-heptamethyltetracontenyl, 1,4,7,10,13-pentaethyltetracontenyl group and the like, carbon Number 6-5
Examples of the aryl group represented by 0 include the aryl groups listed for R, dioctylphenyl, trioctylphenyl, dinonylphenyl, didecylphenyl, didodecylphenyl, tetradecylphenyl, ditetradecylphenyl,
Hexadecylphenyl, dihexadecylphenyl, octadecylphenyl, octadecenylphenyl, dioctadecylphenyl, icosylphenyl, diicosylphenyl, docosylphenyl, tetracosylphenyl, hexacosylphenyl, octacosylphenyl, Examples thereof include octacocenylphenyl, triacontylphenyl, triacontenylphenyl, tetracontylphenyl, and tetracontenylphenyl groups.

The alkyl group represented by R ₁ may be substituted or the like. First, a specific silane compound when it is not substituted is as follows. Examples of the compound represented by the general formula (a) include octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyltrimethoxysilane, decyltriethoxysilane, hexadecyltriethoxysilane, Octadecyltriethoxysilane, octadecenyltrimethoxysilane, tetradecyltrimethoxysilane, 2-ethylhexyltrimethoxysilane, 8-methylheptadecyltrimethoxysilane, 2-heptylundecyltriethoxysilane, nonylphenyltrimethoxysilane, dioctyl Examples of phenyltriisopropoxysilane and tetradecyltriethoxysilane represented by the general formula (b) include dioctyldimethoxysilane and didecyldimethoxy. Orchids, didodecyl dimethoxysilane, di hexadecyl dimethoxysilane, di octadecyl dimethoxysilane, didecyl diethoxy silane, di-hexadecyl diethoxy silane, di-octadecyl diethoxy silane,
Di (3,5,5-trimethylhexyl) diisopropoxysilane, di (8-merheptadecyl) dimethoxysilane), di (methylphenyl) dimethoxysilane, di (dodecylphenyl) diethoxysilane, ditetracosyldibutoxysilane Examples of the compound represented by the general formula (c) include, for example, tridodecylmonoisopropoxysilane,
Examples include trioctylmethoxysilane, tri (2-ethylhexyl) methoxysilane, tri (1-methylhexyl) monoethoxysilane, triphenylmonoethoxysilane, tridecylmonomethoxysilane, tridecylmonoethoxysilane, and trioctadecylmonoethoxysilane. To be

Among them, dodecyltrimethoxysilane, tetradecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyltrimethoxysilane, dodecyltriethoxysilane, tetradecyltriethoxysilane, hexadecyltrimethoxysilane represented by the general formula (a). Ethoxysilane and octadecyltriethoxysilane are preferred.

Next, the case where the alkyl group represented by R ₁ is substituted will be described. Examples of the silane compound in which the alkyl group represented by R ₁ is substituted with a hydroxy group include 6-hydroxyhexyltrimethoxysilane, 12-hydroxyoctadecyltriethoxysilane, p-hydroxyphenyltrimethoxysilane and di (6-hydroxyhexyl). ) Diethoxysilane, tri (10-hydroxydecyl) monobutoxysilane, 10
-Hydroxydecyltrimethoxysilane, and 12-hydroxydodecyltrimethoxysilane.

Examples of the silane compound in which the alkyl group represented by R ₁ has a sulfur atom include 6-methylthiohexyltrimethoxysilane, di (6-mercaptohexyl) diethoxysilane, p-mercaptophenyltrimethoxysilane and 12-mercapto. Dodecyltrimethoxysilane,
Mention may be made of 10-mercaptodecyltriethoxysilane.

As the silane compound in which the alkyl group represented by R ₁ has an oxygen atom or a nitrogen atom, for example, a silane compound having a primary or secondary amino group in the alkyl group and having a carbon number of less than 6 can be prepared by the following epoxy Examples thereof include those in which the chain length of the alkyl group is adjusted to 6 or more carbon atoms by the ring-opening reaction. As a specific synthesis method, a silane compound containing a primary or secondary amine is added to a compound having an epoxy group at room temperature to 80.
If added dropwise at a temperature of ℃, it can be synthesized by stirring and mixing without catalyst for 4 to 8 hours.

[0028]

[Chemical 4]

(In the formula, R represents a linear or branched alkyl group or alkenyl group having 2 or more carbon atoms, or a phenyl group.)

The alkyl group used as a raw material has 1,2
Examples of the silane compound having a primary amino group include di- (6-aminohexyl) -diethoxysilane, 4-aminobutyltrimethoxysilane, 8-aminooctyltriethoxysilane, 10-aminodecyldodecyldimethoxysilane and 3 Examples include-(2'-aminoethyl) aminopropyltrimethoxysilane, 3- (2'-aminoethyl) aminopropylmethyldimethoxysilane, and 3-aminopropyltrimethoxysilane. Further, the compound having an epoxy group is a compound having a carbon number of 3 to 30, and examples thereof include 1,2-epoxyoctane, and 1,2-epoxyoctane.
-Epoxydodecane, 1,2-epoxyoctadecane,
2-ethylhexyl glycidyl ether, epoxy cyclohexane, 3- (2'-butyloxyethyloxy)
-1,2-epoxy propane, glycidol, butyl glycidyl ether, phenyl glycidyl ether, nonyl phenyl glycidyl ether, octyl glycidyl ether, lauryl glycidyl ether, oleyl glycidyl ether, stearyl glycidyl ether, polyalkylene glycol monoglycidyl ether and the like can be mentioned.

Of the silane compounds obtained above, 3-
(2′-aminoethyl) aminopropyltrimethoxysilane or 3-aminopropyltrimethoxysilane,
Epoxy ring-opening reaction products with lauryl glycidyl ether, stearyl glycidyl ether, or 1,2-epoxydodecane are preferred.

The silane compound in which the alkyl group represented by R ₁ has an oxygen atom and a nitrogen atom is the same as above.
A silane compound in which the alkyl group has an epoxy group,
By the following epoxy ring-opening reaction, the alkyl chain length can be freely adjusted to prepare an oil-soluble dispersant and a friction reducing agent.

[0033]

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(In the formula, R represents a linear or branched alkyl group or alkenyl group having 2 or more carbon atoms, or a phenyl group.)

Examples of the silane compound having an epoxy group as an alkyl group used as a raw material include 3-glycidoxypropyltrimethoxysilane, 2,3-epoxypropyltrimethoxysilane and 4-glycidoxybutyltrimethoxy. Examples thereof include silane and 3,4-epoxybutyltrimethoxysilane. The primary and secondary amines have 1 to 30 carbon atoms, and include, for example, ethylamine, octylamine, 2-ethylhexylamine, dodecylamine, octadecylamine, octadecenylamine, phenylamine, nonylphenylamine. ,
Examples thereof include dihexylamine, dioctylamine, di (2-ethylhexyl) amine, dioctadecylamine, dioctadecenylamine, diphenylamine and di (nonylphenyl) amine.

Of the silane compounds obtained above, 3-
An epoxy ring-opening reaction product of glycidoxypropyltrimethoxysilane and laurylamine or stearylamine is preferable.

Further, as the silane compound in which the alkyl group represented by R ₁ is substituted with a carboxy group, an alkoxycarbonyl group or the like, a silane compound having a double bond in the molecule, acrylic acid, acrylic ester, methacrylic It is obtained by copolymerizing with a compound having a double bond such as an acid or a methacrylic acid ester as follows, and the alkyl chain length can be adjusted before use. As a result, the silane compound has a carboxy group, an alkoxycarbonyl group, an alkenoxycarbonyl group, and an aryloxycarbonyl group. As a specific synthesis method, for example, in the presence of a polymerization catalyst, a temperature of 60 ° C. is 4 to 8
It can be synthesized by stirring for a time.

[0038]

[Chemical 6]

(In the formula, R represents a hydrogen atom, a linear or branched alkyl group or alkenyl group having 6 or more carbon atoms, or a phenyl group.)

Examples of the silane compound having a double bond in the molecule used as a raw material include 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, 3-diallylaminopropyltrimethoxysilane and di (3-methacryl ane. Roxypropyl) dimethoxysilane and the like. As the compound having a double bond such as methacrylic acid ester, methacrylic acid, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate, acrylic acid, octyl acrylate, decyl acrylate, Dodecyl acrylate, octadecyl acrylate, phenyl acrylate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate and the like can be mentioned.

Of the silane compounds obtained above, 3-
Polymers of methacryloxypropyltrimethoxysilane and decyl acrylate, decyl methacrylate, or octadecyl methacrylate are preferred.

In the silane compound used in the present invention as described above, the methoxy group, the ethoxy group and the like in the silane compound are converted to the compound (I) by the following reaction due to the mixing of water generated by combustion, The compound (I) adsorbs to the sludge component in the engine oil and improves the oil dispersion effect. Further, the compound (I) is adsorbed on the friction portion and effectively acts as a friction reducing agent.

[0043]

[Chemical 7]

The silane compound is contained in the engine lubricating oil composition in the range of 0.05 to 10% by weight, preferably 0.5 to 10.
Addition of 3% by weight improves the friction reducing effect and the cleaning effect. If the amount added is less than 0.05% by weight, the cleaning effect is poor, and if it exceeds 10% by weight, it is economically uneconomical.

The silane compound can be used alone as an engine lubricating oil additive, but by blending it with a base detergent together with a metallic detergent as the component (B) to prepare an engine lubricating oil composition, It is more preferable because the heat resistance of the oil can be maintained.

The metallic detergent as the component (B) is not particularly limited as long as it has been conventionally used as a metallic detergent. For example, petroleum sulfonic acid having a molecular weight of 250 to 600, synthetic sulfonic acid (hereinafter, Sulfonate-based detergent), C6-20 alkylphenol sulfide polymer (hereinafter referred to as phenate-based detergent), C6-20 alkyl salicylic acid (hereinafter referred to as phenate-based detergent).
It is called a salicylate-based detergent. ), A neutral salt of an alkaline earth metal salt of an organic acid such as a fatty acid having 8 to 22 carbon atoms,
Alternatively, an overbased compound containing a carbonate of an alkaline earth metal salt (in particular, calcium or magnesium salt) can be used.

The amount of the metallic detergent as the component (B) varies depending on the type of fuel used, but is usually 0.5 to 50% by weight in the lubricating oil composition for engines, and is 5 for marine products. -50% by weight, and 0.5-10% by weight for land use.

The base oil used in the engine lubricating oil composition of the present invention is not particularly limited, and those generally used as base oils in engine lubricating oils can be used. 250 mm ² / s: 4
Mineral oil or synthetic oil at 0 ° C. is used. Here, the mineral oil refers to paraffinic hydrocarbons, aromatic hydrocarbons or a mixture thereof, and synthetic oils include poly-α-olefins, esters, polyglycols and the like.

The engine lubricating oil additive of the present invention is (A)
The engine lubricating oil composition of the present invention can be obtained by using the component (B) and the component (C) together with the extreme pressure lubricant (C) and the ashless dispersant (D).

The extreme pressure lubricant as the component (C) is not particularly limited, and conventionally known ones can be used. Examples thereof include zinc dialkyldithiophosphate, zinc alkylphosphate, calcium alkylphosphate, amine salt of alkylphosphate, alkylphosphate ester, and fatty acids.

The component (C) extreme pressure lubricant is preferably added to the engine lubricating oil composition in an amount of 0.05 to 5.0% by weight, more preferably 0.1 to 1.0% by weight. Is.

The ashless dispersant as the component (D) is not particularly limited, and conventionally known ones can be used. Among them, carboxylic acid compounds and amide (imide) compounds are generally used.

Representative examples include alkyl succinimides having an alkyl group derived and amides of fatty acids,
Dibasic acids such as succinic anhydride derived from isobutylene having 20 to 100 carbon atoms, succinic anhydride derived from polyolefin having 50 to 150 carbon atoms, and alkenyl succinic acid derived from linear alkenyl group having 8 to 30 carbon atoms; Examples thereof include lauric acid, stearic acid, behenic acid and imides of the following amine compounds. That is, as the amine compound, polyethylene polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine are used.

The ashless dispersant as the component (D) is preferably contained in the engine lubricating oil composition in an amount of 0.1 to 10% by weight, more preferably 0.5 to 5.0% by weight. is there.

The engine lubricating oil composition of the present invention may be copolymerized with a lauryl methacrylic acid ester having a molecular weight of 10,000 to 100,000 depending on the region to be used, the conditions and the required characteristics, as long as the effects of the present invention are not impaired. "Pour point depressant" or "viscosity index improver", whose basic skeleton is ter,
"Antioxidants" such as t- butyl para-cresol, "metal deactivators" such as triphenyl phosphite Faito, further viscosity from 10 to 100,000 mm ² / s: "defoamer" of 25 ° C. dimethyl silicone Can be blended.

It is a well-known technique to use silicone oil as a defoaming agent for engine oil. At this time, the silicone oil used is a dimethyl silicone type represented by the following general formula and is classified as a siloxane compound. It is something. This silicone oil has poor solubility in engine oil, and is usually added to engine oil in the range of several ppm to several tens of ppm and used in a dispersed state to obtain a defoaming effect. However, the effect of reducing friction and the effect of cleaning and dispersing as in the present invention cannot be expected.

[0057]

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[0058]

EXAMPLES The present invention will be described in more detail with reference to Examples, Comparative Examples and Test Examples, but the present invention is not limited to these Examples.

Test Example 1. Evaluation of Detergency The detergency of the engine lubricating oil compositions (Examples 1 to 14 and Comparative Examples 1 to 5) was evaluated using the hot tube tester shown in FIG. That is, engine oil and air that have been subjected to a deterioration treatment in advance are inserted into a glass tube heated to a constant temperature, and the adhered state of dirt components due to deterioration of the engine oil is observed,
It was evaluated as a lacquer score. The silane compounds used in the examples were commercial products except for Examples 4, 5, 6, 12, and 18, but the silane compounds used in the other examples were synthesized by the following operations.

(Synthesis Method of Compound Used in Example 4) 1 mol of dilaurylamine was dissolved in ethanol (30% dilaurylamine / ethanol), and stirred at room temperature with 1 mol of 3-glycidoxypropyltrimethoxysilane. Was added dropwise over 2 hours and then stirred for 4 hours to complete the reaction (no catalyst). After completion of the reaction, ethanol solvent was subjected to reduced pressure (10 mmHg) topping at a temperature of 60 ° C. to obtain an epoxy ring-opening reaction product (dilauryl-3-amino-N- (2-hydroxy) propyltrimethoxysilane).

(Synthesis Method of Compound Used in Example 5) 3
1 mol of-(2-aminoethyl) aminopropyltrimethoxysilane was dissolved in ethanol (30% concentration), 1 mol of nonylphenol glycidyl ether was added dropwise over 2 hours under stirring at room temperature, and then the reaction was terminated by stirring for 4 hours. .
After completion of the reaction, depressurize the ethanol solvent at a temperature of 60 ° C.
mHg) topping, epoxy ring-opening reaction product [3-
(2 ′-(N- (nonylphenyloxy-2 ″ ′-hydroxypropyl) amino) ethylamino) propyltrimethoxysilane] was obtained.

(Synthesis Method of Compound Used in Example 6) 0.2 mol of vinyltrimethoxysilane and 2 mol of lauryl methacrylate were dissolved in ethanol (10% concentration), stirred and then heated to a temperature of 60 ° C. Polymerization initiator (trade name, V-6
5% was dissolved in 1% by weight of the above raw material in ethanol (diluted and dissolved in 1%) and added dropwise (dropping time was 1 hour). After the dropping was completed, the reaction was aged for 3 hours. After completion of the reaction, ethanol as a solvent was topped at a temperature of 70 ° C. under reduced pressure (5 mmHg) to obtain a copolymer of vinyltrimethoxysilane and lauryl methacrylate. The copolymer obtained by this operation had an average GPC molecular weight of 2000.

(Method for synthesizing compound used in Example 12)
A silane compound was synthesized in the same manner as in Example 4 except that laurylamine was used instead of dilaurylamine in Example 4.

(Method for synthesizing compound used in Example 18)
A silane compound was synthesized in the same manner as in Example 5 except that 3-aminopropyltrimethoxysilanelaurylamine was used in place of 3- (2-aminoethyl) aminopropyltrimethoxysilane in Example 5.

(Setting conditions) Engine oil insertion amount: 6 ml / 16 hours Air insertion amount: 10 ml / min. Heating part temperature: 290-320 ° C

(Engine Oil Deterioration Treatment Method) Assuming acidic substances (sulfuric acid), combustion products (soot), and abrasion powder (iron powder) mixed during actual operation, each engine oil is pretreated under the following conditions. did. That is, carbon black, iron powder, and sulfuric acid were added to the engine oil in the following proportions, and the mixture was stirred and mixed at a temperature of 100 ° C. for 10 minutes and used as a test oil. Carbon black: 0.2% by weight of engine oil 5μ or less iron powder: 0.05% by weight of engine oil Sulfuric acid: 0.8% by weight of engine oil

(Evaluation Method) The glass tube after the 16-hour test was compared with a predetermined standard color, and a rating point of 1 to 10 was given. Evaluation point 1: The glass tube was the most stained and turned black (black carbonization). Evaluation point 5: The glass tube was in a moderately soiled state and turned into a pale yellow color. Evaluation point 10: The glass tube has the least contamination and is almost in the same state as the original glass tube.

(Composition of Engine Oil) A test oil for engine oil was prepared by blending the component (A) and other components in the compositions shown in Tables 1 and 2. The various additives used in this formulation were as shown below. Metallic detergent: Commercial calcium salicylate (described as Ca-salicylate) = 300 TBN Commercial calcium sulfonate (described as Ca-sulfonate) = 320 TBN Commercial calcium phenate (described as Ca-phenate) = 170 TBN * TBN: Alkaline value Is indicated and is expressed in KOH mg / g. Extreme pressure lubricant: Commercially available primary type zinc dithiophosphate is used. Ashless dispersant: Commercially available polybutenyl succinimide is used. Base oil: Commercially available natural mineral oil (paraffinic mineral oil), viscosity = 120 mm ² / s: 40 ° C. is used. The above results are shown in Tables 3 and 4.

[0069]

[Table 1]

[0070]

[Table 2]

[0071]

[Table 3]

[0072]

[Table 4]

As is clear from the results of Tables 3 and 4,
Although the cleaning performance of the silane compound is slightly different depending on its structure, the cleaning effect was improved with any silane compound, and it was found that the cleaning performance of the engine oil was improved regardless of the type of the metal-based detergent. In addition, the silane compound does not deteriorate the cleaning performance of engine oil even if the amount of the metal-based detergent added decreases, and further maintains the cleaning performance without decreasing the cleaning effect even when the ashless dispersant is not added. I found out that Therefore, it is possible to add no ashless dispersant or to reduce the addition amount.

Test Example 2. Detergency evaluation Nissan Motor Co., Ltd. 4-cylinder diesel engine SD-
22 was used to evaluate the cleanliness of the piston. As the fuel, a mixture of A heavy oil / light oil (1: 1) was used, and a fuel prepared by TNPS (di-tert-nonylpolysulfide) to have a sulfur concentration equivalent to C heavy oil (3%) was used. The detailed experimental conditions and engine types used are described below.

(Engine used) Type: 4 cycles, 4 cylinders, water-cooled diesel engine Displacement: 2.2 liters Combustion method: Sub-chamber type bore x stroke: 80 x 83.6 mm Compression ratio: 22.2

(Engine test conditions) Engine test time: 100 hours Engine speed: 3000 rpm Fuel: A heavy oil / light oil (1/1) + TNPS (S = 3%) blended product

(Evaluation site of cleanliness and evaluation standard) Evaluation site of cleanliness: Piston land (Top, 2nd, 3rd
, See FIG. 2) Criteria for evaluation of cleanliness: Contamination of the piston land was classified and evaluated as follows. A: No discoloration B: Light yellow discoloration (discoloration within 1/3 area of piston circumference direction) C: Discoloration light yellow (discoloration within 1/3 area of piston circumference direction) D: Carbon adhered (piston circle) E: carbon adhered (circumferential direction 1/3 area or less) E: carbon adhered (piston circumferential direction 1/3 area or more adhered) F: carbon adhered (almost entire surface)

(Test Oil) The oil used in Test Example 1 was used. (Results) The above results are shown in Table 5.

[0079]

[Table 5]

It can be seen that the engine oil containing the silane compound has higher cleanliness than the additive-free product (Comparative Example 1) at each portion from the piston Top land to the 3rd land.

Test Example 3. Friction coefficient measurement The effect of silane compounds was examined using a Soda pendulum type friction tester. (Test method and test conditions) Test method: A Soda pendulum type friction tester (80 g on both sides of the load, 40 g vertical load) was used to measure the friction coefficient of the pretreated test oil. Friction test Measurement temperature: 80 ℃, 150 ℃ Type of friction test material: Soda pendulum type friction test ball = steel (× 4) Soda pendulum type friction test pin = steel (× 1)

(Method for Treating Test Oil) Each engine oil was treated in advance under the following conditions, assuming that an acidic substance (sulfuric acid) mixed in during actual operation is assumed. That is, sulfuric acid was added to the engine oil in the following proportions, and the mixture was stirred and mixed at a temperature of 100 ° C. for 10 minutes to prepare a test oil. Addition amount of sulfuric acid: 0.02% by weight to engine oil

(Evaluation method) The friction coefficients of various test oils were measured, and the lower the friction coefficient, the better. (Composition and Result of Test Engine Oil) Table 6 collectively shows the composition and friction coefficient of the test engine oil.
The raw materials (lubrication additive) used for the blending were as follows. (1) Metal-based detergent: Calcium salicylate (commercially available) Alkaline value = 300TBN (2) Ashless dispersant: Polybutenylsuccinimide (commercially available) (3) Phosphorus extreme pressure agent: Primary zinc dithio Phosphate (commercially available) (4) Viscosity index improver: Lauryl methacrylate polymer (commercially available) Average molecular weight = 30000 (5) Ester type oiliness improver: Oleic acid triglyceride (commercially available) (6) Base oil: Natural mineral Oil (paraffinic mineral oil) Viscosity = 120mm ² / s: 40 ° C

[0084]

[Table 6]

As is clear from the results in Table 6, the engine oil (test oil) to which the silane compound was added had a temperature of 80 ° C.
And 150 ° C., the effect of effectively lowering the friction coefficient was shown, and the friction coefficient was not deteriorated even at 150 ° C. Further, the engine oil to which the silane compound is added exhibits a low friction coefficient even without adding the phosphorus-based extreme pressure agent and the ester type oiliness improver, and the addition amount of these can be made low.
Further, it can be seen that the addition amount of the silane compound is 0.05% or more, which is particularly effective in lowering the friction coefficient.

[0086]

According to the lubricating oil additive for engines of the present invention, the cleaning effect of the piston of the engine can be improved and the friction reducing effect can be obtained. As a result, the addition of phosphorus-based extreme pressure agents and ester-based oiliness improvers (ester-based lubricants), which are conventionally used as metal-based detergents and friction-reducing agents, can be reduced or eliminated. It is possible to extend the life of engine oil. Therefore, the engine lubricating oil composition of the present invention containing the additive is excellent in the piston cleaning effect and the friction reducing effect.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a hot tube tester used for evaluation of cleanliness of a lubricating oil composition in Test Example 1.

FIG. 2 is a diagram showing a portion where piston cleanliness is evaluated in Test Example 2.

[Procedure amendment]

[Submission date] July 26, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0077

[Correction method] Change

[Correction content]

(Evaluation site of cleanliness and evaluation standard) Evaluation site of cleanliness: Piston land portion (Top, 2n
d, 3rd, see FIG. 2) Evaluation criteria for cleanliness: The dirt state of the piston land portion was classified and evaluated as follows. A: No discoloration B: pale yellow in color (piston circumferentially 1/3 discoloration in the area below) C: discolored to light yellow (color change in piston circumferentially 1/3 area than on <br/>) D: Carbon Adhered (adhered to piston circumferential direction ⅓ area or less) E: carbon adhered (piston circumferential direction ⅓ area or greater) F: carbon adhered (almost entire surface)

Claims (6)

[Claims] 1. An engine lubricating oil additive comprising a silane compound. 2. A silane compound is represented by the following general formula (a):
The lubricating oil additive for engines according to claim 1, which is one or more selected from the group consisting of compounds represented by (b) and (c). Embedded image (In the formula, R represents a hydrogen atom, a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkenyl group having 2 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms. ₁ represents a linear or branched alkyl group having 6 to 50 carbon atoms, a linear or branched alkenyl group having 6 to 50 carbon atoms, or an aryl group having 6 to 50 carbon atoms, and the alkyl group is a nitrogen atom or oxygen. It may have an atom or a sulfur atom, or may be substituted with a hydroxy group, a carboxy group, an alkoxycarbonyl group, an alkenoxycarbonyl group, or an aryloxycarbonyl group.) 3. A lubricating oil composition for engines, comprising 0.05 to 10% by weight of the lubricating oil additive according to claim 1 or 2. 4. An engine lubricating oil composition comprising a base oil blended with (A) the lubricating oil additive according to claim 1 or 2, and (B) a metallic detergent. 5. The engine lubricating oil composition according to claim 4, further comprising (C) an extreme pressure lubricant and (D) an ashless dispersant. 6. A base oil comprising (A) the lubricating oil additive according to claim 1 or 2 in an amount of 0.05 to 10% by weight, (B) a metal-based detergent in an amount of 0.5 to 50% by weight, and (C). Extreme pressure lubricant 0.0
The engine lubricating oil composition according to claim 5, which comprises 5 to 5% by weight and 0.1 to 10% by weight of the ashless dispersant (D).