JPH1161166A - Engine oil for ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an engine oil composition for ships, having excellent neutralizing actions on produced sulfuric acid and capable of improving preventing properties of corrosion and abrasion. SOLUTION: This engine oil for ships is obtained by including (A) 1-30 mass.% overbasic alkaline earth metallic phenate having >400 mg KOH/g and <=500 mg KOH/g base number, <=1,000 mm<2> /s viscosity at 100 deg.C and 1-20 mass.% total amount of fatty acids, (B) 0.5-15 mass.% overbasic alkaline earth metallic salicylate having >200 mg KOH/g and <=350 mg KOH/g base number and (C) 0.5-15 mass.% overbasic alkaline earth metallic salicylate having 100-200 mg KOH/g base number in a base oil of a mineral oil, a synthetic lubricating oil or a mixture of both.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine engine oil composition, and more particularly, to a marine diesel engine using a high sulfur fuel, which has a maximum capacity in a field where corrosion resistance to sulfuric acid is required. The present invention relates to a marine engine oil composition that can be used only to a maximum extent.

[0002]

2. Description of the Related Art Generally, heavy oil containing a large amount of sulfur is used as fuel used in marine diesel engines. May be used. A large amount of sulfur oxides (hereinafter referred to as SOx) will be contained in the combustion exhaust gas when using the fuel containing these high sulfur contents. This SOx reacts with the moisture present in the surroundings to form sulfuric acid, which may cause parts such as engine components to corrode and wear. For this reason, marine engine oils are required to have the ability to suppress corrosion and wear caused by sulfuric acid. In conventional marine engine oils, it has been understood that a large amount of sulfuric acid can be neutralized by adding a fixed amount of a high base number overbased metal type detergent, thereby suppressing the corrosive wear of cylinder liners and piston rings. .

[0003]

In a marine diesel engine, there is a possibility that a high-sulfur degraded fuel may be used in the future, and as a result, sulfur oxides in the exhaust gas will increase, and It is thought that the sulfuric acid generated in the above also increases. In order to neutralize this sulfuric acid, it is conceivable to add a high base number overbased metal type detergent. However, a high base number overbased metal type detergent used in conventional marine cylinder oil is considered. Simply increasing the amount of the agent may not sufficiently neutralize sulfuric acid, and there may be a tendency for corrosion wear of cylinder liners, piston rings, and the like to increase. Accordingly, an object of the present invention is to provide a marine engine oil composition that has excellent neutralizing properties for the generated sulfuric acid and improves the prevention of corrosion and abrasion.

[0004]

SUMMARY OF THE INVENTION The present inventors have found that in the above marine diesel engines, such as crosshead and trunk piston engine oils, a high base number, overbased metal type detergent is used in a cylinder. Focusing on being the largest factor in suppressing the corrosion wear of liners and piston rings, and as a result of studying this corrosion wear phenomenon, a high base number overbased metal By blending a specific nonionic surfactant as an additive with the detergent, they found that an engine oil composition having the optimum performance of preventing corrosion and abrasion of cylinder liners and piston rings was obtained. Diesel engine oil composition "(JP-A-5-239485). In addition, an engine oil composition which has abrasion resistance and high detergency and exhibits good low-temperature fluidity by blending a specific amount of a specific calcium phenate and a specific calcium salicylate as an overbased metal type detergent. And found an "engine oil composition" (Japanese Unexamined Patent Application Publication No. 8-28
No. 3764). In addition, by combining a specific calcium phenate and a specific calcium salicylate in a specific amount as an overbased metal type detergent, it has an excellent neutralizing property against the generated sulfuric acid and prevents corrosion and abrasion. A marine engine oil composition which improves the stiffness was found, and a "marine engine oil composition" (Japanese Patent Application No. Hei 8-29467).
No. 3, Japanese Patent Application No. 8-294677).

The present inventors have further studied the corrosion and abrasion phenomenon from the viewpoint of neutralization of sulfuric acid. As a result, a specific overbased alkaline earth metal phenate and two types of overbased having different base numbers were obtained. It has been newly found that, by blending a specific amount of the alkaline earth metal sulfide salicylate, a marine engine oil composition having an optimal cylinder liner and anti-corrosion property of the piston ring can be obtained as in the above invention. The present invention has been completed.

That is, the marine engine oil composition of the present invention is characterized in that the base oil (A) having a base number exceeding 400 mg KOH / g is added to the base oil of mineral oil or synthetic lubricating oil or a mixture of both.
100 mgKOH / g or less, the viscosity at 100 ° C. is 1000 mm ² / s or less, and the total amount of fatty acids is 1
Overbased alkaline earth metal phene
(B) base number is 200 mg KOH
/ G of overbased alkaline earth metal salicylate exceeding 350 mgKOH / g and (C) an overbased alkaline earth metal salicylate having a base number of 100-200 mgKOH / g. 0.5 to 15% by mass
It is intended to provide a marine engine oil composition characterized by being contained. Hereinafter, the present invention will be described in detail.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The overbased alkaline earth metal phenate of the component A in the present invention has a base number of 400 mgK.
OH / g, 500 mgKOH / g or less;
00 viscosity at ℃ is 1000 mm ² / s or less, preferably 100 to 1000 mm ² / s, 1 to 20 wt% of the fatty acids is the total amount, preferably from 5 to 16 wt%. Further, the overbased alkaline earth metal phene of component A
G is a base oil of SAE standard No. 40 lubricating oil base number 30mg
ASTM D2 diluted to KOH / g and without addition of copper catalyst
Hydrolysis is carried out in the same manner as in the hydrolysis stability test method of No. 619-88, and the base number retention rate of the supernatant oil obtained by centrifuging the sample after 24 hours is preferably 70% or more, more preferably 80%. % Or more, more preferably 90%
That is all.

[0008] Overbased alkaline earth metal phenates are
In particular, overbased alkaline earth metal phenates are preferred. Overbased alkaline earth metal phenates include overbased calcium phenate, overbased barium phenate,
Various overbased alkaline earth metal phenates, such as overbased strontium phenate and overbased magnesium phenate, can be used, but overbased calcium phenate is preferred. As the overbased calcium phenate, various overbased calcium phenates can be used, and overbased sulfurized calcium phenate is particularly preferred. A method for producing the overbased alkaline earth metal phenate of the component A is disclosed in Japanese Patent Application No. 9-131.
No. 603.

[0009] Overbased sulfurized alkaline earth metal phenates include phenols, dihydric alcohols, alkaline earth metal oxides or hydroxides or mixtures thereof (hereinafter referred to as alkaline earth metal reagents) and sulfur. It is obtained by reacting the added product or a product obtained by adding water thereto, and then subjecting a distillation column bottom obtained by distilling off an excess amount of dihydric alcohol and at least an excess amount of water to carbon dioxide treatment. . In a preferred embodiment of the overbased sulfurized alkaline earth metal phenate, the method for producing the overbased sulfurized alkaline earth metal phenate includes the step of: Exist at the latest by the carbon dioxide treatment, and about 0.3 to 0.8 per mole of the alkaline earth metal reagent.
Overbased sulfurized alkaline earth metal phenates, especially overbased calcium sulfide phenates, obtained by performing carbon dioxide treatment in the presence of molar water.

The raw materials used in producing the overbased sulfurized alkaline earth metal phenate are as follows. Examples of the phenols include phenols having a hydrocarbon side chain having 4 to 36 carbon atoms, preferably 8 to 32 carbon atoms, such as an alkyl group, an alkenyl group, and an aralkyl group. Specific examples of these phenols include hydrocarbon groups such as butyl, amyl, octyl, nonyl, dodecyl, cetyl, ethylhexyl, and triacontyl, or liquid paraffin, wax, and petroleum such as olefin polymers (polyethylene, polypropylene, polybutene, etc.). Phenols having a group derived from a hydrocarbon are exemplified. The phenols are used alone or in a mixture of two or more. The phenols are desirably those that can become liquid at about 130 ° C. or lower, preferably about 120 ° C. or lower.

As the alkaline earth metal reagent, an oxide or hydroxide of an alkaline earth metal or a mixture thereof is usually used. For example, calcium, barium,
An oxide or hydroxide such as strontium and magnesium is used. The amount of the phenol used is 1 to 100 equivalents, preferably 1.6 to 10 equivalents, per 1 mol of the alkaline earth metal reagent. If the amount of the phenol relative to the alkaline earth metal reagent is too small, the intermediate will gel and the reaction will not proceed further, and the desired good product cannot be obtained. On the other hand, if the amount of the phenol relative to the alkaline earth metal reagent is too large, not only the yield of the product relative to the raw material decreases, but also the utility and time spent for recovering the phenol increase, which is economically disadvantageous.

Next, a dihydric alcohol having a relatively low boiling point, a low viscosity and a high reactivity is used. The dihydric alcohol preferably has 2 to 6 carbon atoms,
Particularly, ethylene glycol and propylene glycol are preferred. Dihydric alcohols help the conversion of phenols to oil-soluble substances by reaction with alkaline earth metal reagents,
It is stabilized and partly incorporated into the product phenate to form multi-equivalent phenate. In the method of the present invention, the metal addition reaction may be carried out with or without the addition of water having a reaction promoting effect. About 0.15 to 3.0 moles, especially about 0.3 moles per mole of metal reagent
~ 1.5 mol is preferred. When the reaction is carried out without adding water, the amount of the dihydric alcohol used is the alkaline earth metal reagent 1
About 1.0 to 3.0 moles, particularly about 1.2 to 3.0 moles per mole
2.0 moles is preferred. If the amount of the dihydric alcohol used is too small, the conversion of the reaction raw materials, particularly the product of the alkaline earth metal reagent, decreases.If the amount is too large, the metal addition reaction to the phenols proceeds smoothly, but the excess The time and utility for distilling off the dihydric alcohol is excessive.

[0013] The amount of sulfur used is the alkaline earth metal reagent 1
0.001 to 3.0 mol per mol, preferably 0.0
1 to 0.5 mol, more preferably 0.05 to 0.4 mol is used. As the amount of sulfur used decreases, the viscosity of the product decreases, but if it is too large, not only does it make it difficult to obtain a product with a high base number because the overbasing of the product decreases, but also the viscosity of the product becomes extremely high As a result, it is impossible to obtain the desired product having a low viscosity and a high base number.

When water is added to the reaction system in the metal addition reaction step of the alkaline earth metal reagent to the phenol in order to promote the reaction, not only distilled water but also canned water, industrial water, and metal addition reaction are used. The quality of the water is not particularly limited, and water in any state such as cold water, hot water, and steam can be used. The water used for promoting the metal addition reaction may be added to the reactor alone with water, or part or all of the water may be added as a mixture with other raw materials such as phenols and dihydric alcohols. The timing of adding water to the reactor is not particularly limited, and may be before or after all of the reaction materials other than water are mixed, but it is preferable to add the water within about one hour after mixing all of the reaction materials.

The amount of water used for promoting the metal addition reaction into the reaction system is about 0.01 to 10 mol, preferably 0.1 to 10 mol, per mol of the alkaline earth metal reagent used.
2.0 moles. When the metal addition reaction is carried out by adding water from the outside to the reaction system, the reaction proceeds smoothly compared with the case where the reaction is carried out under the same conditions except that water is not added, and the reaction raw material, particularly the alkaline earth metal reagent Product conversion rate increases.
Therefore, if the amount of water added to the reaction system is too small, the product conversion of the alkaline earth metal reagent will decrease. Conversely, if the amount is too large, the advantage that the distillation step after the reaction is simplified is lost.

The addition of water coexisting during the carbon dioxide treatment is carried out by reacting a raw material mixture comprising phenols, dihydric alcohols, alkaline earth metal reagents and sulfur, or water added thereto. After completion of the metal sulfide addition reaction, distillation is generally carried out after distilling off water and excess dihydric alcohol. There is no limitation on the quality and state of the water coexisting during the carbon dioxide treatment, similarly to the water used for promoting the metal addition. The amount of water in the reaction system is from 0.3 to 0.8 mol, preferably from 0.3 to 0.8 mol per mol of the alkaline earth metal reagent.
Adjust to 0.6 mole. If there is an excess of dihydric alcohol in the system, any water in the system such as water added at the time of distillation and water generated by the reaction is distilled off as a forerunner. After distilling off the excess, it is necessary to add a predetermined amount of water. On the other hand, if there is no excess dihydric alcohol in the system,
After the completion of the reaction, only the excess amount may be distilled off, leaving only a predetermined amount of water from the water present in the system, such as water added for promoting the reaction before the metal sulfide addition reaction or water generated during the reaction. However, when the remaining amount is unclear, it is preferable to add a predetermined amount of water after once distilling off the entire amount of water. The amount of water coexisting during carbon dioxide treatment increases the base number of the product as it increases, but if the amount is too large, the product is too hydrolyzed, causing a decrease in the base number and oil solubility, and if the amount is too small, The effect of improving the base number of the product cannot be sufficiently obtained.

The fatty acids to be present before the carbon dioxide treatment include, for example, those having 10 to 30 carbon atoms, preferably 16 carbon atoms.
To 24 fatty acids or salts thereof, and in the case of a salt, an alkaline earth metal salt is preferable. Examples of the alkaline earth metal include calcium, barium, magnesium, strontium and the like. Further, it is more preferable that the alkyl group has a straight chain. Specific examples of the fatty acids include, for example, decanoic acid, capric acid, lauric acid, palmitic acid, stearic acid, behenic acid, lignoceric acid, serotinic acid, montanic acid, melicic acid and the like. is there. The fatty acids may be a mixture having a molecular weight distribution, and commercially available stearic acid having a stearic acid purity of about 60 to 70% can be used. The amount of the fatty acids is 0.001 to 0.3 mol, preferably 0.01 to 1 mol per mol of the alkaline earth metal reagent.
０．３0.3 mol, more preferably 0.05-0.3 mol, and most preferably 0.05-0.2 mol. If the amount of the fatty acid to be added is small, the base number of the phenate is not further improved, and the hue and the oil solubility are reduced. If it is too large, the base number will decrease.

In the above method for producing an overbased sulfurized alkaline earth metal phenate, a diluent or a solvent (hereinafter, referred to as a diluent) having an appropriate viscosity for facilitating the handling of reactants, reaction intermediates or products. .) Can be added. For example, when recovering excess unreacted phenols from the reaction product after completion of the metal addition reaction step or carbon dioxide treatment by distillation, the reaction should be performed at a high boiling point and in the presence of a diluent having an appropriate viscosity. As a result, the bottom of the reaction column can be obtained in a desired liquid state. Note that, usually, a part of the diluent is also distilled off as the unreacted phenols are distilled off. Therefore, when repeatedly using the recovered phenols for the reaction, a diluent that does not directly affect the reaction is desirable. The reaction may be performed in the presence of a diluent. Examples of preferred diluents include petroleum fractions of suitable viscosity, such as paraffinic, naphthenic, aromatic, or mixed base oils, for example, having a boiling point of about 22
0 to 550 ° C, viscosity is about ^{2 to} 40 mm ² / s at 100 ° C
Lubricating oil fractions. Other organic solvents also exhibit hydrophobicity and lipophilicity, and can be used as a diluent if they are harmless at the time of reaction or in the application of the product. For example, higher alcohols having 8 to 24 carbon atoms can be used.

In the method for producing an overbased sulfurized alkaline earth metal phenate, it is preferred that an alkaline earth metal reagent, phenols and sulfur, or these and water are first charged into a reactor to form a charged mixture. Also,
These may be charged with fatty acids together. The order of charging these reactants and reactants is not particularly limited and may be appropriately selected.

The above mixture is mixed with a dihydric alcohol at a pressure in the reactor of 0 to 200 kPa-G, preferably 0 to 200 kPa-G.
It is preferable to add in a state of １００100 kPa-G. By adding the dihydric alcohol to the above mixture in this pressure range, an overbased sulfurized alkaline earth metal phenate having a high base value and excellent hydrolysis stability can be produced. The addition of the dihydric alcohol is preferably performed within the above-mentioned range of the pressure in the reactor, but at least 60% by mass or more, preferably 8% by mass or more of the total amount of the dihydric alcohol.
It is desirable that the content be 0% by mass or more in the above range.

The temperature of the charged mixture at the time of adding the dihydric alcohol is preferably 60 ° C. or higher, particularly preferably 120 ° C. or higher. The upper limit temperature of the charged mixture at the time of adding the dihydric alcohol is usually not higher than the boiling point of the charged mixture, but is preferably not higher than 200 ° C. It is preferable that the dihydric alcohol to be added is also heated to this temperature range in advance. The addition time of the dihydric alcohol is usually 20 to
90 minutes, preferably 30 to 60 minutes. After completion of the addition of the dihydric alcohol, the reaction is carried out at a temperature of about 60 to 200 ° C, preferably about 90 to 190 ° C. The pressure is not particularly limited, and is selected in the range of 0.01 to 21 atm · A, preferably 0.1 to 11 atm · A. This reaction is almost completed within a period of usually 1 to 9 hours.

In the carbon dioxide treatment step, after completion of the metal addition reaction, excess dihydric alcohols and at least excess water in the system are distilled off, and if fatty acids are not added first or fatty acids added first If the amount is small,
After adding fatty acids to a predetermined amount and allowing a predetermined amount of water to exist in the system, the reaction temperature is about 50 to 230 ° C.
Preferably, it is reacted with carbon dioxide under a temperature condition of 80 to 200 ° C. This reaction may be performed under reduced pressure, normal pressure, or increased pressure. Usually, a range of 0.01 to 51 atm.A, preferably 0.1 to 31 atm.A is employed. The reaction is generally carried out until the absorption of carbon dioxide is substantially stopped, and is for 20 minutes to 10 hours, usually 20 minutes to 3 hours.
The product obtained here may be further subjected to 0 to 20 atm. G, preferably 0 to 10 atm.
It is maintained at a pressure of G at about 100 to 230 ° C. for several minutes to several tens of hours. The product is further improved in oil solubility and stability in marine engine oil by carbon dioxide treatment.

The timing of adding the fatty acids may be any time from the time of adding the raw materials to the reactor and before the carbon dioxide treatment step, but is preferably before the addition of water to be added during the carbon dioxide treatment. An alkaline earth metal reagent and a dihydric alcohol or, if necessary, a fatty acid are added to the reaction product after the carbon dioxide treatment, and a metal addition reaction as described above is performed again. By repeating the above, further metal addition can be performed. It is preferable to recover some or most of the unreacted phenols in the reaction product after the carbon dioxide treatment from the viewpoint of economy and the like, and it is also possible to reuse the recovered phenols as a raw material. it can. If the unreacted phenols are distilled in the presence of a normal diluent such as a high-boiling mineral oil, the distillation residue can be obtained in a preferable liquid form. Insoluble substances in the distillation residue can be removed by an operation such as filtration or centrifugation before or after the recovery of phenols.

The overbased sulfurized alkaline earth metal phenate has a base number exceeding 400 mg KOH / g and 500 mg KOH / g.
KOH / g or less, and the viscosity at 100 ° C. is 100
0mm ² / s or less, preferably 100~1000mm ² /
s, and further, the fatty acids are 1 to 20% by mass of the total amount,
Preferably it is 5 to 16% by mass. The overbased sulfurized alkaline earth metal phenate is diluted with a base oil of SAE viscosity standard No. 40 to a base number of 30 mgKOH / g and contacted with 5% by mass of water at 93 ° C. for 24 hours. Is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more.
The overbased sulfurized alkaline earth metal phenate has the above properties, and because of these properties, has a high base number and is excellent in hydrolytic stability and oil solubility. The compounding ratio of the overbased alkaline earth metal phenate of the component A, which is one of the essential components in the present invention, is 1 to 30% by mass, and preferably 1 to 20% by mass. When the amount is less than 1% by mass, a sufficient base number cannot be obtained and the effect is reduced. When the amount exceeds 30% by mass, the effect is not improved merely by providing an excessive base number.

The overbased alkaline earth metal salicylate of the component B, which is one of the essential components in the present invention, has a base number exceeding 200 mgKOH / g and 350 mgKOH / g.
And particularly preferably 250 mgKOH / g to 3 mg
50 mgKOH / g. Further, the overbased alkaline earth metal salicylate of the component C, which is one of the essential components in the present invention, has a base number of 100 to 200 mgKOH / g.
And preferably 150 to 200 mgKOH / g. The above overbased alkaline earth metal salicylates are:
There are a calcium salt, a magnesium salt and the like, but a calcium salt is preferred. The B component is α- having 20 to 30 carbon atoms.
The olefin and the C component are 14 to 18 α-olefins, and phenol is alkylated to form an alkylphenol metal salt, a carboxyl group is introduced by a Kolbe-Schmidt reaction, and an alkaline earth metal salt is formed by metathesis or the like. Used (JP-B-61-24560, JP-B-6-24)
1-224651). The overbased type is
It is produced by treating the neutral form with carbon dioxide.

The mixing ratio of the overbased alkaline earth metal salicylate is 0.5 to 15% by mass, preferably 0.5 to 10% by mass. If the proportion of the overbased alkaline earth metal salicylate is too small, the effect is not sufficient, and if it is too large, the effect cannot be improved for the added amount. The proportions of the above-mentioned overbased alkaline earth metal phenate of the component A, the overbased alkaline earth metal salicylate of the component B, and the overbased alkaline earth metal salicylate of the component C are as follows. In the base number ratio of the components, A: (B +
C) = 10: 1 to 1: 1 is preferred, and particularly preferably 7: 1 to 1: 1. Further, the mixing ratio of the B component and the C component is preferably B: C = 1: 4 to 4: 1, and particularly preferably B: C = 1: 2 to 2: 1 in terms of the base number ratio of each component. .

In the present invention, the above components A, B and C are mixed with a base oil composed of a mineral lubricating oil, a synthetic lubricating oil or a mixture of both. The base oil has a normal lubricating oil viscosity and has a viscosity index of 85 to 85.
140 are preferred. In the case of a mineral oil-based lubricating oil, a mineral oil-based lubricating oil fraction may be used by purifying it by appropriately combining solvent refining, hydrorefining, and the like. Examples of the synthetic lubricating oil include C4-C12 dialkyl diesters such as C3-C12 α-olefin polymers, α-olefin oligomers, dioctyl sebacate and other sebacates, azelates, adipates, and the like. ,
Examples thereof include polyol esters such as 1-trimethylolpropane, esters obtained from pentaerythritol and a monobasic acid having 3 to 12 carbon atoms, and alkylbenzenes having an alkyl group having 9 to 40 carbon atoms. The mineral lubricating oil and the synthetic lubricating oil can be used alone or in combination of two or more.

In the marine engine oil composition of the present invention, besides the above-mentioned additives, various known additives may be used, if necessary, for example, ashless dispersants such as alkenylsuccinimide or derivatives thereof, and dialkyl. Various antioxidants such as zinc thiophosphate such as zinc dithiophosphate, phenolic compounds such as 2,6-di-tert-butyl-p-cresol, aromatic amine compounds such as N-dimethylaniline, molybdenum dialkyldithiophosphate, etc. Various anti-wear agents, polymethacrylates, ethylene-propylene copolymers, styrene-isoprene copolymers, hydrogenated styrene-isoprene copolymers or various viscosity index improvers such as polyisobutylene, sulfurized oils and fats, diphenyl sulfide, Methyl trichlorostearate, chlorinated naphthalene, iodine Benzyl, fluoroalkyl polysiloxanes, various extreme pressure agents, carboxylic acids, including stearic acid, such as lead naphthenate, dicarboxylic acids, metal soaps, carboxylic acid amine salts, metal salts of heavy sulfonic acid,
Various rust inhibitors such as carboxylic acid partial esters and phosphoric esters of polyhydric alcohols, various friction modifiers such as higher fatty acids, higher alcohols, amines and esters, and various antifoaming agents such as silicone oils. They can be appropriately combined in combination of more than one kind. In addition to these, various additives can be appropriately compounded.

The method for preparing the marine engine oil composition of the present invention may be carried out by appropriately mixing the base oil, the above essential components, and various additives as necessary. The mixing order is not particularly limited. The essential components may be sequentially mixed with the oil, or the essential components may be previously mixed and then mixed with the base oil. Further, various additives may be added to the base oil in advance, or may be added to essential components. The base number of the marine engine oil composition of the present invention obtained by blending the above components may be usually 5 to 100 mgKOH / g, preferably 10 to 70 mgKOH / g. Further, the marine engine oil composition of the present invention is suitable for a marine diesel engine using a high-sulfur fuel, and the high-sulfur fuel referred to here is a K-standard of Japanese Industrial Standard which is a domestic standard.
The kinematic viscosities specified in 2205 are one to three, and the sulfur content is No. 1 to No. 3. Specifically, the sulfur content is in the range of 0.5 to 3.5%, and further includes heavy oil of 3.5% or more supplied outside.

[0030]

Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited at all by these examples. In Examples, an engine oil composition was prepared by mixing essential components and various additives with a base oil, and a sulfuric acid neutralization test, piston cleanliness, and corrosion of a piston ring were evaluated. The types of base oils, essential components and additives used in the preparation of the engine oil compositions of the respective examples and comparative examples, and the respective evaluation tests are as follows. (1) Base oil SAE40 (American Society of Automobile Engineers has an automotive lubricant having a viscosity number of 40 and a kinematic viscosity at 100 ° C of 12.
It was used for viscosity index 100 5~16.3mm mineral oil ² / s).

(2) Calcium phenate A (TBN)
(Base number: 444 mg KOH / g) In a 1-liter autoclave equipped with a stirrer, a gas inlet tube and a thermometer, 531.2 g (1.9 mol) of 97.9% pure dodecylphenol, 96.0% pure 40.91 g (0.7 mol) of calcium oxide and 3.37 g (0.105 mol) of sulfur (0.15 mol per mol of calcium oxide), 25.2 g of stearic acid (0.1 mol).
091 mol) (0.13 mol per mol of calcium oxide) was stirred and stirred. The obtained suspension was heated to 125 ° C, and 65.21 g (1.05 mol) of ethylene glycol having a purity of 94.5% was added to the suspension at 125 ° C and 60 ° C.
kPa-G under a pressure of 30 minutes.
Pressure of about 500 kPa-G, and about 3.0
After stirring for a period of time, the generated water, some unreacted ethylene glycol and a small amount of dodecylphenol were distilled off while gradually reducing the pressure in the reaction system to obtain 791.9 g of a liquid distillation residue. . The final distillation temperature at this time was 141 ° C. (5 mmHg). Next, 6.30 g (0.35 mol) of water (0.5 mol per mol of calcium oxide) was added to 791.9 g of the distillation residue, and carbon dioxide was absorbed at a temperature of 150 ° C. from a reduced pressure for 30 minutes. I let it. At this time, the supply rate of carbon dioxide to the autoclave was 0.315 l / min. Then, the temperature was raised to 178 ° C., and the pressure was increased again with carbon dioxide until the gauge pressure reached 5.0 atm.
I got To the reaction product was added 58.92 g of 150 neutral oil as a diluent. The reaction product was transferred to a 1-liter three-necked pear-shaped flask at 820.78 g and distilled under reduced pressure to distill off a small amount of ethylene glycol and most of unreacted dodecylphenol.
I got The final distillation temperature at that time is 225 ° C. (3 mmH
g). Thereafter, the distillation residue was diluted with a large amount of hexane, and after removing 2.15 g of insoluble matter by centrifugation, 164.39 g of a final product was obtained by removing the large amount of hexane by distillation. Properties of final product and S
AE standard No. 40 lubricating base oil with a base number of 30 mg KOH /
g ASTM D2619 without addition of copper catalyst
93 ° C. in the same operation as the hydrolysis stability test method of -88.
For hydrolysis. As a result of measuring the base number of the supernatant oil obtained by centrifuging the sample after 24 hours, the base number retention rate after hydrolysis was 98%. The properties are shown below. Properties (i) Base number Perchloric acid method 444 mg KOH / g (ii) Fatty acid content 15.3% by mass (iii) Viscosity (100 ° C) 390 mm ² / s (IV) Base number retention 98%

(3) Calcium salicylate B (TBN)
(300 mgKOH / g) A phenol was alkylated with an α-olefin having 20 to 30 carbon atoms, and then a carboxyl group was introduced by a Kolbe-Schmidt reaction, and then a calcium salt was obtained by metathesis or the like. (4) Calcium salicylate C (TBN 170 mgK
OH / g) A phenol was alkylated with an α-olefin having 14 to 18 carbon atoms, and then a carboxyl group was introduced by a Kolbe-Schmidt reaction, and then a calcium salt was obtained by metathesis or the like. (5) Alkenyl succinimide A polyolefin having a molecular weight of 30 to 3000 is reacted with maleic anhydride and then imidized with a polyamine, or the resulting imide is reacted with an aromatic polycarboxylic acid to obtain the remaining amino acid. A group in which a group is partially amidated (for example, a polybutene having a molecular weight of 900 is reacted with maleic anhydride, and then imidized with tetraethylenepentamine, or a product obtained by allowing trimellitic acid to act on this). And so on.

(6) Antifoaming agent A silicone antifoaming agent (commercially available additive) was used. (7) Commercial calcium phenate A (TBN 250 mg
(KOH / g) (i) Base number 250 mg KOH / g (ii) Viscosity 300 mm ² / s (100 ° C.) (iii) Base number retention 33%

Evaluation Test (1) Sulfuric Acid Neutralizing Test 10.0 g of the compositions of Examples and Comparative Examples as test oils were placed in a branch-equipped 300 ml Myr flask and heated. When the temperature of the test oil reached 50 ° C., 0.15 ml of concentrated sulfuric acid equivalent to 30 mg KOH / g was added and stirred,
2 minutes with a fine differential pressure gauge set in a flask, 4
And the CO ₂ generation pressure after 6 minutes were measured, and C per hour was measured.
It is evaluated that the higher the O ₂ generation pressure, the more the corrosion wear can be suppressed. (2) Evaluation of Piston Cleanliness and Corrosion Wear of Piston Rings A 2.2-liter, single-cylinder, diesel engine with an engine speed of 1500 rpm and a test time of 10
After continuous operation for 0 hours, after the test, cleanliness of the piston and corrosion wear of the cylinder liner and the piston ring were evaluated. The fuel oil at this time was JI with a sulfur content of 2.5%.
S, a type equivalent to No. 3 type 1 was used.

Examples 1 to 4 Calcium phenate A, calcium salicylate B, and calcium salicylate C were blended with the above base oil at the ratios (% by mass) shown in Table 1 to prepare marine engine oil compositions. The results of the sulfuric acid neutralization test of the obtained marine engine oil composition are as shown in the lower part of Table 1. Note that the balance in the table means that the amount of the base oil is selected such that the total amount of each component blended in the engine oil is 100% by mass.

[0036]

[Table 1]

Comparative Examples 1 to 7 The above-mentioned base oils and additives were blended to prepare marine engine oil compositions. The mixing ratio (% by mass) is shown in the upper part of Tables 2 and 3, and the result of the sulfuric acid neutralization test is shown in the lower part of Tables 2 and 3.

[0038]

[Table 2]

[0039]

[Table 3]

Example 5 and Comparative Examples 8 and 9 Further, calcium phenate A, calcium salicylate B, calcium salicylate C, alkenyl succinimide and an antifoaming agent were added to the above base oil in the proportions shown in Table 4 (% by mass). ), The blended marine engine oil composition was prepared, and the corrosion wear of the cylinder liner and the piston ring and the cleanliness of the piston were evaluated using a bench engine. The results are shown in Table 4, and the results are shown as ratios when Comparative Example 9 is set to 1.0.

[0041]

[Table 4] Note) W. T. D: Total demerit rating, T.D. G. FIG. F:
Top ring groove clogging

[0042]

The marine engine oil composition of the present invention contains a specific overbased alkaline earth metal sulfide and two overbased alkaline earth metal salicylates having different base numbers. By doing so, the corrosion resistance to sulfuric acid is excellent, and it also has high cleanliness. The marine engine oil composition of the present invention is extremely useful in practical use.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ken Suzuki 1134-2 Gongendo, Satte City, Saitama Pref.

Claims (2)

[Claims] (1) a base oil of a mineral oil or a synthetic lubricating oil or a mixture of the two, wherein (A) the base number is more than 400 mgKOH / g and 500 mgKOH / g or less, and the viscosity at 100 ° C. is 1000 mm ² / s or less. 1 to 30% by mass of an overbased alkaline earth metal phenate having a total amount of fatty acids of 1 to 20% by mass, and (B) a base number of 200 m
0.5 to 15% by mass of an overbased alkaline earth metal salicylate exceeding 350 gKOH / g and not more than 350 mgKOH / g, and (C) a base number of 100 to 200 mgKOH / g.
g of the overbased alkaline earth metal salicylate
A marine engine oil composition characterized by containing 15% by mass. 2. The component (A) is diluted with a base oil of SAE standard No. 40 to a base number of 30 mgKOH / g, and the hydrolysis stability test method of ASTM D2619-88 is performed without adding a copper catalyst. And a centrifugal separation of the sample after 24 hours to obtain an overbased sulfurized alkaline earth metal phenate having a base number retention of 70% or more. Item 4. A marine engine oil composition according to Item 1.