JPH08165486A - Lubricating oil composition for two-cycle engine - Google Patents

Abstract

(57) [Summary] [Object] To provide a lubricating oil composition for a two-cycle engine, which has improved cleanliness capable of effectively suppressing deposits in a piston portion and a combustion chamber, as compared with a normal two-cycle engine oil. To do. [Constitution] For the lubricating base oil, (A) polybutene and / or
Alternatively, it is a lubricating oil composition for a two-cycle engine, which comprises polyisobutylene and (B) a substituted hydroxyaromatic carboxylic acid and an ester obtained from a hydroxy compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil composition for a two-stroke engine, and more particularly, to a deposit in a piston portion and a combustion chamber, as compared with a two-stroke engine oil containing a conventional polybutene and a detergent dispersant. TECHNICAL FIELD The present invention relates to a lubricating oil composition for a two-cycle engine, which has improved cleanliness capable of effectively suppressing substances.

[0002]

2. Description of the Related Art Recently, in a two-cycle engine,
It is required to improve the durability and reliability of the engine by suppressing deposits (improving cleanliness) in the piston portion and the combustion chamber. Specifically, it is an issue to prevent output reduction due to ring sticking, poor starting, seizure, engine stall due to plug deposit, etc. Therefore, in two-cycle engine oil, improvement of cleanliness is an urgent task. . Heretofore, a two-cycle engine oil having excellent high-temperature detergency has been proposed in which a base dispersant is blended with a polyamide dispersant (ashless dispersant), a metal dispersant, etc. 6-240276 publication).
However, in this two-cycle engine oil,
There is a problem that sufficient cleanliness is not achieved in the vicinity of pistons such as piston rings and piston heads, and in high temperature parts such as cylinder heads.

[0003]

SUMMARY OF THE INVENTION Under such circumstances, the present invention effectively deposits in the piston portion and in the combustion chamber as compared with a two-cycle engine oil containing ordinary polybutene and a detergent dispersant. It is an object of the present invention to provide a lubricating oil composition for a two-cycle engine with improved detergency that can be suppressed.

[0004]

DISCLOSURE OF THE INVENTION As a result of intensive studies to develop a lubricating oil composition for a two-cycle engine having the above-mentioned preferable properties, the present inventors have found that polybutene and polybutene can be added to a lubricating base oil. Isobutylene (polyisobutene)
At the same time, it was found that the purpose can be achieved by blending a substituted hydroxyaromatic carboxylic acid ester. The present invention has been completed based on such findings. That is, the present invention is a two-cycle engine in which (A) polybutene and / or polyisobutylene, and (B) a substituted hydroxyaromatic carboxylic acid and an ester obtained from a hydroxy compound are mixed with a lubricating base oil. A lubricating oil composition for use is provided. Further, a preferred embodiment of the present invention is based on the total amount of the composition, based on the total amount of the composition of the lubricating base oil, 0.1 to 50% by weight of the above component (A) and 0.1% of the component (B).
A lubricating oil composition for a two-cycle engine, containing 1 to 30% by weight.

As the base oil in the lubricating oil composition of the present invention, mineral oil or synthetic oil is usually used. There are no particular restrictions on the type of mineral oil or synthetic oil, etc., but the kinematic viscosity at 100 ° C is usually 1.5 to 40 mm ² / sec.
Are used. Here, examples of the mineral oil include paraffin-based mineral oil, intermediate-based mineral oil, and naphthene-based mineral oil obtained by ordinary refining methods such as solvent refining and hydrogenation refining. Examples of synthetic oils include ethylene-propylene copolymers, polyolefins [α-olefin homopolymers and copolymers],
Examples include various esters (for example, polyol ester, dibasic acid ester, phosphoric acid ester, etc.), various ethers (for example, polyphenyl ether, etc.), alkylbenzene, alkylnaphthalene, and the like.

In the present invention, the mineral oil may be used alone or in combination of two or more as the base oil. Further, the above synthetic oils may be used alone or in combination of two or more. Furthermore, one or more mineral oils and one or more synthetic oils may be used in combination. Other,
Kerosene, light oil, solvent or a mixture thereof may be further added and used. In the composition of the present invention, polybutene and / or polyisobutylene is used as the component (A). As the polybutene and polyisobutylene, those having a number average molecular weight of 300 to 4,000 are usually used. If this number average molecular weight exceeds 4,000, the cleanliness will not be sufficiently exhibited, and if it is less than 300, the performance of the resulting composition as a lubricating oil may deteriorate. From the viewpoint of cleanliness and performance as a lubricating oil, the preferable number average molecular weight is in the range of 400 to 1,200.

The component (A), polybutene or polyisobutylene, may be used alone or in combination of two or more. Further, the compounding amount thereof is usually selected in the range of 0.1 to 50% by weight based on the total amount of the composition. If the blending amount is less than 0.1% by weight, the effect of improving cleanliness cannot be sufficiently exhibited. On the other hand, if it exceeds 50% by weight, the improvement of the effect is not recognized for the amount, and it is rather economically disadvantageous. From the viewpoint of the effect of improving the cleanliness and the economical efficiency, the preferable blending amount is 5 to
It is in the range of 50% by weight. In the lubricating oil composition of the present invention, an ester obtained from a substituted hydroxyaromatic carboxylic acid and a hydroxy compound is used as the component (B). Examples of the substituted hydroxyaromatic carboxylic acid which is the acid component of the above ester include compounds represented by the general formula (I)

[0008]

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[Wherein Ar is a polyvalent aromatic nucleus, R is an organic group, p is an integer of 1 to 3, n is an integer of 1 to 4 and m is 1 to 3]
When the number of Rs is plural, the plural Rs may be the same or different. ] The compound represented by these can be mentioned. In the general formula (I), Ar
Indicates a polyvalent aromatic nucleus. Examples of the polyvalent aromatic nucleus include those derived from benzene, naphthalene, anthracene, phenanthrene, indene, fluorene, biphenyl and the like. Among these, those derived from benzene and naphthalene are particularly preferable.
In addition to the hydroxyl group, the organic group (R), and the carboxyl group, Ar may also have a halogen atom, a nitro group,
A mercapto group or the like may be substituted.

R is an organic group such as a hydrocarbon group, an alkoxy group and a dialkylamino group, and a hydrocarbon group is particularly preferable. When there are a plurality of Rs, the plurality of Rs may be the same or different. The hydrocarbon group is not particularly limited, and is a chain hydrocarbon group such as an alkyl group or an alkenyl group, a cyclic hydrocarbon group such as a cycloalkyl group or a cycloalkenyl group, or an aromatic carbon group such as a phenyl group or a naphthyl group. It may be any of hydrogen groups, but is preferably a chain hydrocarbon group such as an alkyl group or an alkenyl group. These hydrocarbon groups may be substituted with another hydrocarbon group such as a lower alkyl group, a cycloalkyl group or a phenyl group.
Further, the hydrocarbon group includes those substituted with a non-hydrocarbon group as long as it retains substantially hydrocarbon-like properties. Examples of the non-hydrocarbon group include a nitro group, an amino group, a halo group, a hydroxyl group, a lower alkoxy group, a lower alkylmercapto group, an oxo group, a thio group and an interrupting group (for example, -NH-, -O-, -S
-) And the like.

Examples of the above hydrocarbon group include propyl group, butyl group, isobutyl group, pentyl group, hexyl group, 1-methylhexyl group, 2,3,5-trimethylheptyl group, octyl group, 3-ethyloctyl group. Group, 4-ethyl-5-methyloctyl group, nonyl group, decyl group, dodecyl group, 2-methyl-4-ethyldodecyl group, hexadecyl group, octadecyl group, eicosyl group, docosyl group, tetracontyl group, 4-hexenyl group , 2-ethyl-4-hexenyl group, 6-octenyl group, 3-cyclohexyloctyl group, phenylnonyl group, nitrododecyl group, 3-aminononyl group, chlorohexadecyl group, (2
-Nitroethyl) octyl group, (3-aminocyclohexyl) nonyl group, 4- (p-chlorophenyl) octyl group, 4-butoxyhexadecyl group, and further olefin polymer (for example, polyethylene, polypropylene, polyisobutylene, ethylene- Hydrocarbon groups derived from propylene copolymer, polychloroprene, chlorinated olefin polymer, oxidized ethylene-propylene copolymer, etc.).

Preferred among the above hydrocarbon groups are:
A linear or branched alkyl group, preferably having 6 carbon atoms
To 7,000, more preferably a hydrocarbon group having 8 to 225 carbon atoms. Specific examples of preferable R include hexyl group, 1-methylhexyl group, 2,3,5-
Trimethylheptyl group, octyl group, 3-ethyloctyl group, 4-ethyl-5-methyloctyl group, nonyl group,
Decyl group, dodecyl group, 2-methyl-4-ethyldodecyl group, hexadecyl group, octadecyl group, eicosyl group, docosyl group, tetracontyl group and other linear or branched alkyl groups, olefin polymers (for example, polyethylene, polypropylene, Examples thereof include linear or branched alkyl groups derived from polyisobutylene, ethylene-propylene copolymer, and the like.

On the other hand, as the alcohol component of the ester, a hydroxy compound having 2 to 80 carbon atoms is preferably used. The hydroxy compound may be an aliphatic alcohol, an aromatic alcohol, a monohydric alcohol or a polyhydric alcohol. The aliphatic alcohol has, for example, 2 carbon atoms.
-24 linear or branched monohydric alcohols, specifically hexanol, octanol, decanol, dodecanol, tetradecanol, hexadecanol, octadecanol, oleyl alcohol, linolenyl alcohol, lauryl alcohol , Myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, etc., relatively high-grade synthetic monohydric alcohols of the type produced by the oxo process (for example, 2-ethylhexyl alcohol), types formed by aldol condensation, Organoaluminum-catalyzed relatively higher synthetic monohydric alcohols of the type formed by oligomerization of α-olefins (eg, ethylene, propylene, etc.) and subsequent oxidation, as well as cyclopentanol, cyclohexene. SANOL, cycloalkyl alcohols, etc., or polyhydric alcohols such as cyclododecanol, specifically, ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, heptylene glycol, 2
-Ethyl-1,3-trimethylene glycol, neopentyl glycol, diethylene glycol, relatively high-grade polyethylene glycol and polypropylene glycol,
Tripropylene glycol, dibutylene glycol, dipentylene glycol, dihexylene glycol, diheptylene glycol, and the general formula HOCH ₂ (C
HOH) _n CH ₂ OH (eg, glycerol, sorbitol, mannitol, etc.) Can be mentioned.

Examples of aromatic alcohols include monohydric alcohols such as phenol, alkylphenol, naphthol, and alkylnaphthol, catechol, alkylcatechol, sulfurized alkylphenol, dihydric alcohols such as methylene-bridged alkylphenol, trihydroxybenzene, and trihydroxybenzene. Examples include trihydric alcohols such as hydroxyalkylbenzene. The alcohol component of the ester is preferably an aromatic alcohol, and particularly preferably an alkyl-substituted aromatic alcohol such as alkylphenol, alkylcatechol and trihydroxyalkylbenzene from the viewpoint of the performance of the obtained ester. Here, the alkyl group is preferably one having 1 to 24 carbon atoms, preferably 6 to 20 carbon atoms, and the alkyl group may be linear or branched, and about 1 to 3 on the aromatic ring. It may be substituted, but one substituted is preferable. In the present invention, specific examples of the ester used as the component (B) include:

[0015]

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And the like. The ester as the component (B) may be used as it is, or may be treated with a boron compound to contain boron. here,
Examples of the boron compound include boric acid, boric anhydride, boron halide, boric acid ester, boric acid amide, and boric oxide. In the lubricating oil composition of the present invention, the ester as the component (B) may be used alone or in combination of two or more. Also,
The blending amount is usually 0.1 to 30 based on the total amount of the composition.
It is selected in the range of weight%. If this amount is less than 0.1% by weight, the effect of improving cleanliness will not be fully exerted, and if it exceeds 30% by weight, the effect will not be improved for that amount, and the viscosity at low temperatures will be rather rather. It causes inconvenience such as rising. From the viewpoints of the effect of improving cleanliness, economical efficiency, viscosity and the like, the preferable blending amount is in the range of 0.5 to 25% by weight.

In the composition of the present invention, if necessary,
A detergent dispersant can be included. As the detergent dispersant, an ashless dispersant or a metal detergent is used. The ashless dispersant is a known one which is usually used in engine lubricating oils, for example, succinimides, boron-containing succinimides, benzylamines, boron-containing benzylamines, succinic acid esters. , Amides of monovalent or divalent carboxylic acids represented by fatty acids or succinic acid. Further, as the metal-based detergent, known ones usually used in engine lubricating oils such as neutral metal sulfonates, neutral metal phenates, neutral metal salicylates, neutral metal phosphonates, basic sulfonates, basic metals are used. Examples thereof include phenates, basic salicylates, basic phosphonates, overbased sulfonates, overbased phenates, overbased salicylates, and overbased phosphonates.

The above ashless dispersants may be used alone or in combination of two or more, and the metallic detergent may be used alone or in combination of two or more. Further, one or more ashless dispersants and one or more metal detergents may be used in combination. The ashless dispersant is usually added in a proportion of 0.1 to 7% by weight based on the total amount of the composition, and the metal-based detergent is usually 0.1 based on the total amount of the composition.
It is mixed in a ratio of 1 to 4% by weight. The lubricating oil composition of the present invention contains additives other than those mentioned above, such as extreme pressure agents, antiwear agents, antioxidants, viscosity index improvers, and fluidizers, if necessary, within a range that does not impair the object of the present invention. A point depressant, a rust preventive, a metal corrosion inhibitor, a surfactant, an antifoaming agent and the like can be added as appropriate.

Examples of extreme pressure agents and antiwear agents include sulfur compounds such as sulfurized fats and oils, sulfurized olefins, dialkyl polysulfides, diarylalkyl polysulfides, diaryl polysulfides, phosphoric acid esters, thiophosphoric acid esters, and phosphorous acid esters. , Alkyl hydrogen phosphite, phosphate amine salt,
Phosphorous compounds such as amine salts of phosphites, chlorinated oils and fats, chlorinated paraffins, chlorinated fatty acid esters, chlorinated compounds such as chlorinated fatty acids, alkyl or alkenyl maleic acid esters, alkyl or alkenyl succinic acid esters Compounds, organic acid compounds such as alkyl or alkenyl maleic acid, alkyl or alkenyl succinic acid, naphthenates, zinc dithiophosphate (ZnDTP), zinc dithiocarbamate (ZnDTC), sulfurized oxymolybdenum organophosphorodithioate (MoDTP) Examples thereof include organometallic compounds such as oxymolybdenum dithiocarbamate sulfide (MoDTC).

Examples of the antioxidant include amine antioxidants such as diphenylamine, alkyldiphenylamine, phenyl-α-naphthylamine and alkylphenyl-α-naphthylamine, 2,6-di-t-butyl-
4-methylphenol; 4,4'-methylenebis (2,2
6-di-t-butylphenol); 4,4'-bis (2,6-di-t-butylphenol); 4,4'-bis (2-methyl-6-t-butylphenol); 2,
2'-methylenebis (4-ethyl-6-t-butylphenol); 2,2'-methylenebis (4-methyl-6-
t-butylphenol); 4,4'-butylidenebis (3-methyl-6-t-butylphenol); 4,4 '
-Thiobis (2-methyl-6-t-butylphenol); 4,4'-thiobis (3-methyl-6-t-butylphenol); 2,2'-thiobis (4-methyl-6)
-T-butylphenol) and other phenolic antioxidants.

Examples of the viscosity index improver include polymethacrylate, dispersion type polymethacrylate, olefin copolymer (eg ethylene-propylene copolymer), dispersion olefin copolymer, styrene copolymer. Examples of the pour point depressant include polymethacrylate and the like (eg, styrene-diene hydrogenated copolymer). Examples of rust preventives include alkenyl succinic acid and its partial esters, and examples of metal corrosion inhibitors include benzotriazole-based, benzimidazole-based, benzothiazole-based, thiadiazole-based antifoaming agents. , Dimethylpolysiloxane, polyacrylate, etc.
For example, polyoxyethylene alkylphenyl ether or the like is used.

[0022]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Examples 1 to 6 and Comparative Examples 1 and 2 Lubricating oil compositions having the component compositions shown in Table 1 were prepared, and detergency was evaluated according to the method shown below. The results are shown in Table 1. <Evaluation of cleanliness> As an engine, Honda DIO AF2
Uses a 7-inch single-cylinder 2-cycle engine with a rotation speed of 6
000 rpm, load: full load, mixing ratio (fuel / oil): 50/1, test time: 3 hours, plug seat temperature: 26
Tested under the conditions of 0 ± 5 ℃, CO concentration: 6.0 ± 0.5%, piston ring sticking, piston land deposit, piston ring groove deposit, piston skirt, piston underside, piston head and cylinder The head was observed and the cleanliness was evaluated. For the evaluation method, the final score (1
The cleanliness was evaluated by setting the maximum score to 00.

[0023]

[Table 1]

[0024]

[Table 2]

[Note] 1) Base oil: 500 neutral and kerosene mixed, 100 ° C.
Kinematic viscosity 8.5 mm ² / sec 2) Polyisobutylene: number average molecular weight 900

[0026]

[Chemical 4]

[0027]

INDUSTRIAL APPLICABILITY The lubricating oil composition for a two-cycle engine of the present invention contains a conventional polybutene and a detergent-dispersant.
It has improved cleanliness compared to cycle engine oil, and can effectively suppress deposits in the piston portion and the combustion chamber, resulting in improved durability and reliability of the engine.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C10N 40:26

Claims (4)

[Claims] 1. A two-cycle engine comprising a lubricant base oil and (A) polybutene and / or polyisobutylene, and (B) an ester obtained from a substituted hydroxyaromatic carboxylic acid and a hydroxy compound. Lubricating oil composition. 2. The blending amount of the component (A) and the blending amount of the component (B) are 0.1 to 50% by weight and 0.1 to 30% by weight, respectively, based on the total amount of the composition. A two-cycle engine lubricating oil composition. 3. The lubricating oil composition for a two-cycle engine according to claim 1, wherein the component (B) is an ester obtained from a substituted hydroxyaromatic carboxylic acid and an alkyl-substituted aromatic alcohol. 4. The substituted hydroxyaromatic carboxylic acid in the component (B) has the general formula (I): [In the Formula, Ar is a polyvalent aromatic nucleus, R is an organic group, p is 1-3.
, N is an integer of 1 to 4, m is an integer of 1 to 3,
When there are a plurality of Rs, the plurality of Rs may be the same or different. ] 1 or 3 which is represented by
The lubricating oil composition for a two-cycle engine described.