WO2016080441A1

WO2016080441A1 - Cylinder lubricating oil composition for scrubber-equipped crosshead diesel engines

Info

Publication number: WO2016080441A1
Application number: PCT/JP2015/082411
Authority: WO
Inventors: 茂樹竹島
Original assignee: Ｊｘ日鉱日石エネルギー株式会社
Priority date: 2014-11-18
Filing date: 2015-11-18
Publication date: 2016-05-26
Also published as: EP3222702A1; KR102420190B1; EP3222702A4; CN107001977A; EP3222702B1; CN107001977B; KR20170084105A; US20170321141A1; SG11201703848XA

Abstract

A cylinder lubricating oil composition for scrubber-equipped crosshead diesel engines, the composition comprising a base oil and (A) a metallic detergent, and having a base number of 15 to 125 mgKOH/g and a kinematic viscosity at 100°C of 10 to 30 mm²/s, and satisfying requirement (i) or (ii). (i) Comprises 0.02 to 5.0 mass% of (B) a demulsifier. (ii) Comprises, as the component (A), (A1) a Ca phenate detergent and (A2) a metallic detergent other than the Ca phenate detergent, includes, as a nitrogen content, 0.015 mass% or less of (C-1')a succinimide or a borated derivative thereof, the succinimide having in the molecule at least one alkyl group or alkenyl group, or does not include the same, and has a Ph value represented by formula (1) of 20×10^-3 or less. Ph value=C_Ca×2/(r_M×40.08) (1) (In formula (1), C_Ca is the calcium content (mass%) derived from the (A1) component, and r_M is the metal ratio of the (A1) component.)

Description

Cylinder lubricating oil composition for crosshead type diesel engine mounted on scrubber

The present invention relates to a cylinder lubricant composition for a crosshead type diesel engine, and more particularly to a cylinder lubricant composition that can be preferably used in a crosshead type diesel engine equipped with a scrubber.

A large number of cross-head type diesel engines are used for main engines of large ships. Therefore, it can be said that the part derived from the emission material of the crosshead type diesel engine is large in the influence of ship operation on the environment.

Environmental issues are growing internationally, and attention is paid to nitrogen oxides (NOx) and sulfur oxides (SOx) contained in exhaust gas discharged from ships into the atmosphere. . The International Maritime Organization (IMO) has determined that Tier III (tertiary regulation) will be effective in the ECA area (Emission Control Area) since 2016 for NOx regulations, and 2020 for SOx regulations. From the year or 2025, it has been studied to reduce the sulfur content of fuel used in general sea areas to 0.5% or less.

The application of scrubber technology is attracting attention as a technology for reducing the concentration of SOx and NOx in ship exhaust gas. EGR (Exhaust Gas Recirculation) scrubbers have attracted attention as NOx reduction technology that can be used for IMO Tier III (Patent Documents 1 to 4). Options for reducing SOx emissions include reducing the sulfur content of the fuel (using low-sulfur fuel), as well as conventional sulfur oxides that are discharged using high-sulfur fuel, and an exhaust gas aftertreatment device Therefore, it can be considered that the amount is equivalent to that when a low sulfur fuel having a sulfur content of 0.5% or less is used. Since the low-sulfur fuel is expensive, the latter method has attracted attention, and it has been proposed to perform a de-SOx treatment using a scrubber as an exhaust gas aftertreatment device (Patent Document 5).

A scrubber (cleaning dust collector) is generally separated by collecting harmful substances (for example, harmful gases and dust) in exhaust gas in droplets or liquid films of absorbing liquid (for example, water). Means device. For example, it is conceivable that SOx is absorbed and separated by an aqueous alkali solution such as an aqueous sodium hydroxide solution, and soot is separated by density difference after being collected in an aqueous phase.

In order to efficiently collect harmful substances in the scrubber, it is necessary to sufficiently bring the gas and the absorbing liquid into contact with each other. Therefore, the scrubber is devised to increase the efficiency of gas-liquid mixing. However, exhaust gas from a diesel engine includes hydrocarbon-based substances such as unburned fuel and lubricating oil mist. Such hydrocarbon substances do not dissolve in water and may emulsify when vigorously mixed and stirred with water. When these hydrocarbon substances and water are emulsified, soot in the exhaust gas is included in the emulsion to form scum, and scum accumulates in the upper part of the absorbing solution, making separation difficult.

Among engine oils used in diesel engines, system oils for crosshead type diesel engines and engine oils for 4-cycle trunk piston type diesel engines are purified by a centrifugal cleaner and used for repeated lubrication. In order to maintain the cleaning effect in the centrifugal cleaner, these lubricating oils are required to have water separability. On the other hand, cylinder oil for cross-head type diesel engines is an once-through lubricating oil that is cleaned by a centrifugal cleaner and is not used repeatedly, and is in contact with water in the centrifugal cleaner. Nor. Therefore, until now, water separation performance has not been required for cylinder oil for crosshead type diesel engines.

JP 2011-157959 A JP 2011-157960 A JP 2012-137092 A Japanese National Patent Publication No. 8-511074 JP 2011-185275 A

The present invention relates to a cylinder lubricant composition for a scrubber-mounted crosshead type diesel engine capable of improving water separation and reducing or suppressing generation of scum from hydrocarbon-based substances, soot, and moisture in the scrubber. The issue is to provide goods.

The first aspect of the present invention is:
Containing a base oil, and (A) a metallic detergent,
The base number is 15 to 125 mg KOH / g,
The kinematic viscosity at 100 ° C. is 10 to 30 mm ² / s,
A cylinder lubricant composition for a scrubber-mounted crosshead diesel engine that satisfies the following requirement (i) or (ii).
(I) Based on the total amount of the lubricating oil composition (B) 0.02 to 5.0% by mass of demulsifier
Containing.
(Ii) As the component (A),
(A1) Ca phenate detergent, and
(A2) contains a metallic detergent other than the Ca phenate detergent,
(C-1 ′) A succinimide having at least one alkyl group or alkenyl group in the molecule or a boronated derivative thereof is contained or contained in an amount of 0.015% by mass or less based on the total amount of the composition. Without
The Ph value represented by the following formula (1) is 20 × 10 ⁻³ or less.
Ph value = C _Ca × 2 / (r _M × 40.08) (1)
(In formula (1), C _Ca represents the calcium content (mass%) derived from the component (A1), and r _M represents the metal ratio of the component (A1).)

In this specification, “a scrubber-mounted crosshead type diesel engine” means a crosshead type diesel engine having a mechanism for purifying gas discharged from a cylinder by at least one scrubber. The scrubber may be an EGR scrubber (for example, see Patent Documents 1 to 4) in which the gas that has passed through the scrubber is guided to the intake side of the cylinder, and the gas that has passed through the scrubber is not guided to the intake side of the cylinder. An exhaust gas scrubber (see, for example, Patent Document 5) may be used. The “crosshead type diesel engine” is typically a crosshead type two-stroke diesel engine.

The first embodiment of the first aspect of the present invention is:
Base oil,
(A) Based on the total amount of the metal detergent and the composition (B) 0.02-5.0% by mass of the demulsifier
Containing
The base number is 15 to 125 mg KOH / g,
A cylinder lubricating oil composition for a scrubber-mounted crosshead type diesel engine having a kinematic viscosity at 100 ° C. of 10 to 30 mm ² / s.

As a preferable form in the first embodiment, a form containing (C) a nitrogen-containing ashless dispersant can be exemplified.

As a preferred embodiment in the first embodiment, (C) a nitrogen-containing ashless dispersant may be contained in an amount of 0.2% by mass or less as a nitrogen content based on the total amount of the lubricating oil composition, or may not be included. .

As a preferred form in the first embodiment, a form in which the component (B) is one or more polyether compounds can be exemplified. In such a form, the number average molecular weight of the component (B) is preferably 500 or more. In the present invention, the “polyether compound” means a compound having a polyether moiety, and the polyether moiety may be further modified with, for example, an ester bond.

As a preferable form in the first embodiment, a form in which the component (A) is Ca phenate can be exemplified.

The second embodiment in the first aspect of the present invention is:
Base oil,
(A1) Ca phenate detergent, and
(A2) contains a metallic detergent other than the Ca phenate detergent,
(C-1) Succinimide having at least one alkyl group or alkenyl group in the molecule or a boronated derivative thereof is contained in 0.015% by mass or less based on the total amount of the composition, or not contained ,
The base number is 15 to 125 mg KOH / g,
The kinematic viscosity at 100 ° C. is 10 to 30 mm ² / s,
A cylinder lubricating oil composition for a scrubber-mounted crosshead type diesel engine having a Ph value represented by the following formula (1) of 20 × 10 ⁻³ or less.
Ph value = C _Ca × 2 / (r _M × 40.08) (1)
(In the formula (1), C _Ca represents the calcium content derived from the component (A1) (mass% based on the total amount of the composition), and r _M represents the metal ratio of the component (A1).)

As a preferred form in the second embodiment, (C) a succinimide having at least one alkyl group or alkenyl group in the molecule or a boronated derivative thereof is more than 0% by mass as a nitrogen content based on the total amount of the composition. The form containing 0.015 mass% or less can be illustrated.

As a preferable form in the second embodiment, a form in which the component (A2) is Ca sulfonate and / or Ca salicylate can be exemplified.

The second aspect of the present invention is:
A step of operating the crosshead type diesel engine while supplying the cylinder lubricating oil composition for a scrubber-mounted crosshead type diesel engine according to the first aspect of the present invention to a cylinder of the crosshead type diesel engine provided with the scrubber; and,
A cylinder lubrication method for a scrubber-mounted crosshead type diesel engine comprising a step of purifying at least a part of gas discharged from a cylinder in a scrubber.

In the second aspect of the present invention, the purification step in the scrubber preferably includes a step of bringing the gas introduced into the scrubber into contact with water and / or a basic aqueous solution.

According to the first aspect of the present invention, there is provided a cylinder oil for a scrubber-mounted crosshead type diesel engine capable of reducing or suppressing generation of scum from hydrocarbon-based material, soot, and moisture in the scrubber. can do.

According to the cylinder lubrication method of the scrubber-mounted crosshead type diesel engine according to the second aspect of the present invention, when purifying the gas discharged from the cylinder in the scrubber, the hydrocarbon-based material, soot, and moisture are contained in the scrubber. It is possible to reduce or suppress the generation of scum.

Hereinafter, the present invention will be described in detail. Unless otherwise specified, the notation “A to B” for the numerical values A and B means “A to B”. In this notation, when a unit is attached to only the numerical value B, the unit is also applied to the numerical value A. Further, the terms “or” and “or” mean logical sums unless otherwise specified.

<Lubricant base oil>
As the base oil in the present invention, at least one selected from mineral oil and synthetic oil can be used.

Although there is no particular limitation on the mineral oil, in general, a normal pressure residue obtained by atmospheric distillation of crude oil is desulfurized, hydrocracked, and fractionated to a desired viscosity grade, and Preferred examples include those obtained by dewaxing or catalytic dewaxing the above normal pressure residual oil, and further extracting with a solvent and hydrogenating as necessary.

Furthermore, as mineral oil, a base oil production process is produced by further distilling atmospheric distillation residue under reduced pressure, fractionating it to a desired viscosity grade, and then dewaxing the solvent through processes such as solvent refining and hydrorefining. Isomerization of petroleum wax isomerized lube base oil produced by hydroisomerization of petroleum wax produced as a by-product in the dewaxing process and GTL WAX (gas-tuly liquid wax) produced by the Fischer-Tropsch process A GTL wax isomerized lubricating base oil produced by the above method can also be used. The basic production process for producing these wax isomerized lubricating base oils is the same as the method for producing hydrocracked base oils.

Further, the synthetic oil is not particularly limited, and a synthetic oil used as a normal lubricating base oil can be used. Specifically, polyα-olefins and hydrides thereof such as polybutene and hydrides thereof; oligomers such as 1-octene, 1-decene, dodecene, or mixtures thereof; ditridecyl glutarate, di-2 -Diesters such as ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate; trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate, etc. Polyol ester; copolymer of dicarboxylic acid such as dibutyl maleate and α-olefin having 2 to 30 carbon atoms; aromatic synthetic oil such as alkyl naphthalene, alkyl benzene, aromatic ester; A mixture etc. can be illustrated.

The kinematic viscosity at 100 ° C. of the base oil is preferably 10 mm ² / s or more, more preferably 14 mm ² / s or more, and preferably 25 mm ² / s or less, more preferably 20 mm ² / s or less. When the kinematic viscosity at 100 ° C. of the base oil is not less than the above lower limit value, a sufficient oil film can be formed at the lubrication site, and good lubricity can be obtained. Moreover, when the base oil has a kinematic viscosity at 100 ° C. of not more than the above upper limit value, good fluidity at low temperatures can be obtained. In the present invention, the kinematic viscosity at 100 ° C. refers to the kinematic viscosity at 100 ° C. defined by ASTM D-445.

As a preferred form of the base oil, a mixed base oil of a base oil having a kinematic viscosity at 100 ° C. of 10 to 14 mm ² / s and a base oil having a kinematic viscosity at 100 ° C. of 20 to 40 mm ² / s can be exemplified. .

The viscosity index of the base oil is preferably 85 or more, more preferably 90 or more, and particularly preferably 95 or more. When the viscosity index of the base oil is not less than the above lower limit, the viscosity at low temperature can be kept low, and good startability can be obtained. In the present invention, the viscosity index means a viscosity index measured in accordance with JIS K2283-1993.

The saturated content of the base oil based on the total amount of the base oil is preferably 50% by mass or more, more preferably 55% by mass or more, and preferably 90% by mass or less, more preferably 75% by mass or less. is there. When the saturated content is equal to or more than the above lower limit value, good oxidation stability can be obtained. Moreover, since sufficient solubility of asphaltenes or a deteriorated product can be obtained when the saturated content is not more than the above upper limit value, good cleanability can be obtained. In the present specification, the saturated content means the saturated content measured by the method described in ASTM D 2007-93.

<(A) Metal-based detergent (1)>
In the first embodiment of the lubricating oil composition of the present invention, (A) the metallic detergent (hereinafter referred to as “component (A)”) is a so-called metallic detergent that is usually used in lubricating oil. is there. Examples of the component (A) include phenate detergents, sulfonate detergents, and salicylate detergents. Moreover, these metal type detergents can be used individually or in combination of 2 or more types.

As the component (A), a phenate detergent can be used particularly preferably.
Preferable examples of the phenate detergent include an alkaline earth metal salt of a compound having a structure represented by the following formula (1) or a basic salt or an overbased salt thereof. Examples of the alkaline earth metal include magnesium, barium, and calcium. Among these, magnesium or calcium is preferable, and calcium is particularly preferable. In addition, (A) component may be used individually by 1 type, and may be used in combination of 2 or more type.

In the formula (1), R ¹ represents a linear or branched chain having 6 to 21 carbon atoms, a saturated or unsaturated alkyl group or alkenyl group, m represents the degree of polymerization and represents an integer of 1 to 10, Represents a sulfide (—S—) group or a methylene (—CH ₂ —) group, and x represents an integer of 1 to 3. R ¹ may be a combination of two or more different groups.

The number of carbon atoms of R ¹ in the formula (1) is preferably 9-18, more preferably 9-15. If the carbon number of R ¹ is less than 6, the solubility in the base oil may be poor. On the other hand, if the carbon number of R ¹ exceeds 21, the production may be difficult and the heat resistance may be poor.

The degree of polymerization m in the formula (1) is preferably 1 to 4. When the degree of polymerization m is within this range, the heat resistance can be increased.

The base number of the phenate detergent is preferably 60 mgKOH / g or more, more preferably 100 mgKOH / g or more, and preferably 350 mgKOH / g or less, more preferably 300 mgKOH / g or less. When the base number is not less than the above lower limit, good acid neutralization can be obtained, and when the base number is not more than the above upper limit, good cleanliness can be obtained. In the present invention, the base number means a base number measured by the perchloric acid method.

Preferred examples of the sulfonate detergent include an alkaline earth metal salt of an alkyl aromatic sulfonic acid obtained by sulfonating an alkyl aromatic compound, or a basic salt or an overbased salt thereof. The weight average molecular weight of the alkyl aromatic compound is preferably 400 to 1500, more preferably 700 to 1300.
Examples of the alkaline earth metal include magnesium, barium, and calcium. Magnesium or calcium is preferable, and calcium is particularly preferable. Examples of the alkyl aromatic sulfonic acid include so-called petroleum sulfonic acid and synthetic sulfonic acid. As petroleum sulfonic acid here, what sulfonated the alkyl aromatic compound of the lubricating oil fraction of mineral oil, what is called mahoganic acid etc. byproduced at the time of white oil manufacture are mentioned. In addition, as an example of synthetic sulfonic acid, linear or branched alkyl obtained by recovering a by-product in an alkylbenzene production plant that is a raw material of a detergent or by alkylating benzene with polyolefin Examples include sulfonated alkylbenzene having a group. Another example of the synthetic sulfonic acid is a sulfonated alkyl naphthalene such as dinonylnaphthalene. Moreover, there is no restriction | limiting in particular as a sulfonating agent at the time of sulfonating these alkyl aromatic compounds, For example, fuming sulfuric acid and anhydrous sulfuric acid can be used.

The base number of the sulfonate detergent is preferably 10 mgKOH / g or more, more preferably 150 mgKOH / g or more, still more preferably 250 mgKOH / g or more, and preferably 500 mgKOH / g or less, more preferably 450 mgKOH / g or less. . When the base number is at least the above lower limit, good acid neutralization can be obtained, and when the base number is at most the above upper limit, good cleanability can be obtained.

Preferred examples of the salicylate detergent include metal salicylate or a basic salt or an overbased salt thereof. Examples of the metal salicylate include a compound represented by the following formula (2).

In the above formula (2), R ² each independently represents an alkyl group or alkenyl group having 14 to 30 carbon atoms, M represents an alkaline earth metal, and n represents 1 or 2. As M, calcium or magnesium is preferable, and calcium is particularly preferable. n is preferably 1. When n = 2, R ² may be a combination of different groups.

As a preferred embodiment of the salicylate detergent, there can be mentioned alkaline earth metal salicylate in which n = 1 in the above formula (2), or a basic salt or an overbased salt thereof.

The production method of the alkaline earth metal salicylate is not particularly limited, and a known production method of monoalkyl salicylate can be used. For example, monoalkyl salicylic acid obtained by alkylation with olefin using phenol as a starting material and then carboxylation with carbon dioxide gas or the like, or alkylation with an equivalent amount of the above olefin using salicylic acid as a starting material. The obtained monoalkyl salicylic acid or the like is reacted with a metal base such as an alkaline earth metal oxide or hydroxide, or these monoalkyl salicylic acid or the like is once converted into an alkali metal salt such as a sodium salt or a potassium salt. Alkaline earth metal salicylate can be obtained by exchanging metal with an alkaline earth metal salt.

The method for obtaining a basic salt of alkaline earth metal salicylate is not particularly limited. For example, alkaline earth metal salicylate and an excess of alkaline earth metal salt or alkaline earth metal base (alkaline earth metal base) Hydroxide or oxide) can be obtained by heating in the presence of water.
The method for obtaining the overbased salt of alkaline earth metal salicylate is not particularly limited. For example, alkaline earth metal salicylate is converted to alkaline earth metal water in the presence of carbon dioxide gas or boric acid or borate. It can be obtained by reacting with a base such as an oxide.

The base number of the salicylate detergent is preferably 60 mgKOH / g or more, more preferably 100 mgKOH / g or more, and preferably 350 mgKOH / g or less, more preferably 300 mgKOH / g or less. When the base number is at least the above lower limit, good acid neutralization can be obtained, and when the base number is at most the above upper limit, good cleanability can be obtained.

The metal ratio of the component (A) is a value calculated according to the following formula, preferably 1 or more, more preferably 3 or more, and preferably 50 or less, more preferably 30 or less.
(A) component metal ratio = (A) component metal content (mol) / (A) component soap group content (mol)
In addition, when (A) component contains 2 or more types of metals, "the metal content (mol) of (A) component" is the sum total of the mol amount of each metal contained in (A) component. Further, when the component (A) contains two or more types of soap groups, the “soap group content (mol) of the component (A)” is the sum of the molar amount of each soap group contained in the component (A). .

In the first embodiment of the lubricating oil composition of the present invention, as the component (A), one or more calcium detergents selected from a Ca phenate detergent, a Ca sulfonate detergent, and a Ca salicylate detergent are used as the component (A). Can be preferably used.
The Ca phenate detergent is a phenate detergent described above using calcium as an alkaline earth metal. That is, it means a calcium salt of alkylphenol sulfide or a basic salt or an overbased salt thereof.
A Ca sulfonate detergent is a sulfonate detergent described above using calcium as an alkaline earth metal. That is, it means a calcium salt of an alkyl aromatic sulfonic acid or a basic salt or an overbased salt thereof.
The Ca salicylate-based detergent is one in which calcium is used as a metal in the above-described salicylate-based detergent. That is, it means calcium salicylate or its basic salt or overbased salt.
When a calcium detergent is used as the component (A), the content thereof is preferably 0.50 to 4.3% by mass as the calcium content based on the total amount of the lubricating oil composition.

<(A) Metal-based detergent (2)>
The second embodiment of the lubricating oil composition of the present invention contains (A1) component, and (A1) Ca phenate detergent and (A2) metal detergent other than Ca phenate detergent.

((A1) Ca phenate detergent)
Examples of (A1) Ca phenate detergent (hereinafter referred to as “component (A1)”) include calcium salts of compounds having the structure represented by the above formula (1), or basic salts or overbased salts thereof. be able to. (A1) A component may be used individually by 1 type and may be used in combination of 2 or more type. A preferred embodiment of the component (A1) is as described above for the phenate detergent.

((A2) metallic detergents other than Ca phenate detergents)
(A2) The metallic detergent other than the Ca phenate detergent (hereinafter referred to as “component (A2)”) is preferably a metallic detergent other than the phenate detergent, and such a metallic detergent. Examples thereof include sulfonate detergents and salicylate detergents. Moreover, these metal type detergents can be used individually or in combination of 2 or more types.

As the sulfonate detergent, the sulfonate detergent described above can be used. Preferred embodiments of the sulfonate detergent are as described above.

As the salicylate detergent, the salicylate detergent described above can be used. Preferred embodiments of the salicylate detergent are as described above.

In a preferred embodiment, the component (A2) is a Ca sulfonate detergent and / or a Ca salicylate detergent.
The base number of the Ca sulfonate detergent is preferably 10 mgKOH / g or more, more preferably 150 mgKOH / g or more, still more preferably 250 mgKOH / g or more, preferably 500 mgKOH / g or less, more preferably 450 mgKOH / g or less. is there. When the base number is at least the above lower limit, good acid neutralization can be obtained, and when the base number is at most the above upper limit, good cleanability can be obtained.
The base number of the Ca salicylate detergent is preferably 60 mgKOH / g or more, more preferably 100 mgKOH / g or more, and preferably 350 mgKOH / g or less, more preferably 300 mgKOH / g. When the base number is at least the above lower limit, good acid neutralization can be obtained, and when the base number is at most the above upper limit, good cleanability can be obtained.

<(B) Demulsifier>
As the (B) demulsifier (hereinafter referred to as “component (B)”) in the first embodiment of the lubricating oil composition of the present invention, a commercially available so-called demulsifier is used without particular limitation. Among these, polyether compounds can be preferably used.

Examples of polyether compounds that can be preferably used as the component (B) include polyoxypropylene glycol monoalkyl ethers such as polypropylene glycol butyl ether and polypropylene glycol stearyl ether; polyoxyethylene polyoxypropylene alkyl ethers (ethylene oxide-propylene oxide copolymers) Polyoxyethylene alkyl ether; Polyethylene glycol fatty acid ester; Polyoxyethylene glycerin fatty acid ester; Polyoxyethylene sorbit fatty acid ester; and Polyoxyethylene sorbitan fatty acid ester, and one or more polyethers selected from these The compounds can be used alone or in combination.

Among these polyether compounds, propylene oxide units such as polyoxypropylene glycol monoalkyl ethers such as polypropylene glycol butyl ether and polypropylene glycol stearyl ether, and polyoxyethylene polyoxypropylene alkyl ethers (ethylene oxide-propylene oxide copolymers). Polyether compounds containing are particularly preferred.

The molecular weight of the component (B) is not particularly limited, but the number average molecular weight is preferably 350 or more, more preferably 500 or more, still more preferably 1000 or more, and preferably 30000 or less, more preferably 10,000 or less. More preferably, it is 5000 or less. (B) When the number average molecular weight of a component is more than the said lower limit, favorable demulsibility can be obtained.

The HLB (hydrophilic-lipophilic balance) value of the component (B) is not particularly limited as long as it exhibits an anti-emulsifying action (emulsion destabilizing action), but is preferably 13 or more, more preferably 14.5 or more. The HLB value is necessarily 20 or less by definition, and preferably 19.5 or less from the viewpoint of affinity with the base oil.

The content of the component (B) in the first embodiment of the lubricating oil composition of the present invention is 0.02 to 5% by mass, preferably 0.03% by mass or more, based on the total amount of the lubricating oil composition. Preferably it is 0.04 mass% or more, Preferably it is 4 mass% or less, More preferably, it is 3 mass% or less. When the content of the component (B) is not less than the above lower limit value, good demulsibility can be obtained.

<(C) Nitrogen-containing ashless dispersant (1)>
The first embodiment of the lubricating oil composition of the present invention may contain (C) a nitrogen-containing ashless dispersant (hereinafter referred to as “component (C)”).
As the component (C), for example, one or more compounds selected from the following (C-1) to (C-3) can be used.
(C-1) Succinimide having at least one alkyl group or alkenyl group in the molecule or a derivative thereof (hereinafter referred to as “component (C-1)”),
(C-2) benzylamine having at least one alkyl group or alkenyl group in the molecule or a derivative thereof (hereinafter referred to as “component (C-2)”),
(C-3) A polyamine having at least one alkyl group or alkenyl group in the molecule or a derivative thereof (hereinafter referred to as “component (C-3)”).

As the component (C), the component (C-1) can be particularly preferably used.
Among the components (C-1), examples of the succinimide having at least one alkyl group or alkenyl group in the molecule include compounds represented by the following formula (3) or formula (4).

In the formula (3), R ³ represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, and h represents an integer of 1 to 5, preferably 2 to 4. R ³ preferably has 60 or more carbon atoms, and more preferably 350 or less.

In formula (4), each R ⁴ independently represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, and may be a combination of different groups. R ⁴ is particularly preferably a polybutenyl group. I represents an integer of 0 to 4, preferably 1 to 3. R ⁴ preferably has 60 or more carbon atoms, and more preferably 350 or less.

When the carbon numbers of R ³ and R ⁴ in the formulas (3) and (4) are equal to or higher than the lower limit value, good solubility in the lubricating base oil can be obtained. On the other hand, by the number of carbon atoms of R ^3, R ⁴ is more than the above upper limit, it is possible to improve the low temperature fluidity of lubricating oil compositions.

The alkyl group or alkenyl group (R ³ , R ⁴ ) in the formulas (3) and (4) may be linear or branched, and preferably, for example, an olefin oligomer such as propylene, 1-butene and isobutene And a branched alkyl group and a branched alkenyl group derived from a co-oligomer of ethylene and propylene. Of these, branched alkyl groups or alkenyl groups derived from oligomers of isobutene conventionally called polyisobutylene, and polybutenyl groups are most preferred.
The preferred weight average molecular weight of the alkyl group or alkenyl group (R ³ , R ⁴ ) in the formulas (3) and (4) is 800-3500.

The succinimide having at least one alkyl group or alkenyl group in the molecule is a so-called monotype succinimide represented by the formula (3) in which succinic anhydride is added only to one end of the polyamine chain. And a so-called bis-type succinimide represented by the formula (4) in which succinic anhydride is added to both ends of the polyamine chain. Either the monotype succinimide and the bis type succinimide may be contained in the lubricating oil composition of the present invention, or both of them may be contained as a mixture.

The method for producing a succinimide having at least one alkyl group or alkenyl group in the molecule is not particularly limited. For example, a compound having an alkyl group or alkenyl group having 40 to 400 carbon atoms and maleic anhydride and 100 Alkyl succinic acid or alkenyl succinic acid obtained by reaction at ˜200 ° C. can be obtained by reacting with polyamine. Here, examples of the polyamine include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine.

Among the components (C-2), examples of the benzylamine having at least one alkyl group or alkenyl group in the molecule include compounds represented by the following formula (5).

In the formula (5), R ⁵ represents an alkyl or alkenyl group having 40 to 400 carbon atoms, and j represents an integer of 1 to 5, preferably 2 to 4. R ⁵ preferably has 60 or more carbon atoms, and more preferably 350 or less.

The production method of component (C-2) is not particularly limited. For example, a polyolefin such as propylene oligomer, polybutene, or ethylene-α-olefin copolymer is reacted with phenol to form alkylphenol, and then formaldehyde, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine The method of making it react with polyamines, such as a Mannich reaction, is mentioned.

Examples of the polyamine having at least one alkyl group or alkenyl group in the component (C-3) include compounds represented by the following formula (7).

In the formula (6), R ⁶ represents an alkyl group or an alkenyl group having 40 to 400 carbon atoms, and k represents an integer of 1 to 5, preferably 2 to 4. R ⁶ preferably has 60 or more carbon atoms, and more preferably 350 or less.

The production method of component (C-3) is not particularly limited. For example, after chlorinating a polyolefin such as a propylene oligomer, polybutene or ethylene-α-olefin copolymer, this is reacted with a polyamine such as ammonia, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or pentaethylenehexamine. A method is mentioned.

Examples of the derivative in component (C-1) to component (C-3) include (i) succinimide, benzylamine or polyamine (hereinafter referred to as “above-mentioned”) having at least one alkyl group or alkenyl group in the molecule. A monocarboxylic acid having 1 to 30 carbon atoms, such as a fatty acid, and a polycarboxylic acid having 2 to 30 carbon atoms (for example, oxalic acid, phthalic acid, trimellitic acid, pyromellitic acid, etc.). In addition, by reacting these anhydrides or ester compounds, alkylene oxides having 2 to 6 carbon atoms, or hydroxy (poly) oxyalkylene carbonate, some or all of the remaining amino groups and / or imino groups are neutralized. Or an amidated modified compound with an oxygen-containing organic compound; (ii) action of boric acid on the above-mentioned nitrogen-containing compound A boron-modified compound in which part or all of the remaining amino group and / or imino group is neutralized or amidated; (iii) by reacting phosphoric acid with the nitrogen-containing compound described above, A phosphoric acid-modified compound in which a part or all of the amino group and / or imino group is neutralized or amidated; (iv) a sulfur-modified compound obtained by allowing a sulfur compound to act on the nitrogen-containing compound described above And (v) a modified compound obtained by combining the above-mentioned nitrogen-containing compound with two or more kinds of modifications selected from modification with an oxygen-containing organic compound, boron modification, phosphoric acid modification, and sulfur modification. . Among these derivatives (i) to (v), by using a boric acid-modified compound of alkenyl succinimide, particularly a boric acid-modified compound of bis-type alkenyl succinimide, the heat resistance of the lubricating oil composition can be further improved. Can be improved.

The molecular weight of component (C) is not particularly limited, but a preferred weight average molecular weight is 1000 to 8000.
In the first embodiment of the lubricating oil composition of the present invention, the content when the component (C) is contained is preferably 0.02% by mass or more as a nitrogen content based on the total amount of the lubricating oil composition, More preferably, it is 0.04 mass% or more, More preferably, it is 0.07 mass% or more, Preferably it is 0.2 mass% or less, More preferably, it is 0.12 mass% or less. When the content of the component (C) is not less than the above lower limit, the coking resistance (heat resistance) of the lubricating oil composition can be sufficiently improved. Moreover, when the content of the component (C) is not more than the above upper limit value, it is possible to obtain good separability of contaminants in the centrifugal cleaner, and to improve water separation and suppress scum generation in the scrubber. Easy to do.

<(C) Nitrogen-containing ashless dispersant (2)>
In the second embodiment of the lubricating oil composition of the present invention, (C-1 ′) a succinimide having at least one alkyl group or alkenyl group in the molecule or a boronated derivative thereof (hereinafter referred to as “(C-1 ') Ingredients') may or may not be contained. However, when the second embodiment of the lubricating oil composition of the present invention contains the component (C-1 ′), the content of the component (C-1 ′) is 0.015 as a nitrogen content on the basis of the total amount of the composition. It is necessary to be not more than mass%. When the content of the component (C-1 ′) is 0.015% by mass or less as the amount of nitrogen, good demulsibility can be obtained and scum generation in the scrubber can be suppressed.

The succinimide having at least one alkyl group or alkenyl group in the molecule is represented by the formula (3) or formula (4) described above for the component (C-1) in the first embodiment. A compound can be illustrated. Preferred embodiments of these compounds are as described above.

As the boronated derivative of succinimide having at least one alkyl group or alkenyl group in the molecule, for example, boric acid acts on the succinimide having at least one alkyl group or alkenyl group in the molecule as described above. By so doing, a so-called boron-modified compound in which a part or all of the remaining amino group and / or imino group is neutralized or amidated can be mentioned.
The molecular weight of the component (C-1 ′) is not particularly limited, but a preferred weight average molecular weight is 1000 to 8000.

<Other additives>
The lubricating oil composition of the present invention may further contain any additive commonly used in lubricating oils depending on the purpose. Examples of such additives include zinc dithiophosphate, antioxidants, antifoaming agents, pour point depressants, metal deactivators, extreme pressure agents and the like.

As the zinc dithiophosphate (ZnDTP), a compound represented by the following formula (5) can be preferably used.

In formula (7), each R ⁷ independently represents a hydrocarbon group having 1 to 24 carbon atoms, and may be a combination of different groups. Preferred examples of the hydrocarbon group having 1 to 24 carbon atoms include linear or branched alkyl groups having 1 to 24 carbon atoms. R ⁷ preferably has 3 or more carbon atoms, preferably 12 or less, and more preferably 8 or less. Moreover, the alkyl group as R ⁷ may be any of a primary alkyl group, a secondary alkyl group, and a tertiary alkyl group, but a primary alkyl group, a secondary alkyl group, or those And primary alkyl groups are most preferred.

Examples of the zinc dithiophosphate (ZnDTP) include, for example, zinc dipropyldithiophosphate, zinc dibutyldithiophosphate, zinc dipentyldithiophosphate, zinc dihexyldithiophosphate, zinc diheptyldithiophosphate, zinc dioctyldithiophosphate, and the like. 18. Dialkyldithiophosphate zinc having a linear or branched (primary, secondary or tertiary, preferably primary or secondary) alkyl group, preferably having 3 to 10 carbon atoms; diphenyl Zinc di ((alkyl) aryl) dithiophosphate having an aryl group or alkylaryl group having 6 to 18 carbon atoms, preferably 6 to 10 carbon atoms, such as zinc dithiophosphate or zinc ditolyldithiophosphate; The mixture of 2 or more types can be mentioned.

The method for producing the zinc dithiophosphate is not particularly limited. For example, it can be synthesized by reacting an alcohol having an alkyl group corresponding to R ⁷ with diphosphorus pentasulfide to synthesize dithiophosphoric acid and neutralizing it with zinc oxide.

In the lubricating oil composition of the present invention, the content of zinc dithiophosphate is preferably 0.03 to 1.0% by mass, more preferably 0.05 to 0.5% by mass, particularly preferably based on the total amount of the composition. Is 0.01 to 0.3% by mass. The zinc dithiophosphate content is preferably such that the phosphorus content in the lubricating oil composition is 25 to 700 ppm by mass, and the phosphorus content in the lubricating oil composition is more preferably 40 ppm by mass or more, The amount is more preferably 50 ppm by mass or more, particularly preferably 80 ppm by mass or more, more preferably 500 ppm by mass or less, still more preferably 300 ppm by mass or less, and particularly preferably 250 ppm by mass or less. If the phosphorus content derived from the zinc dithiophosphate in the lubricating oil composition is 25 ppm by mass or more, the necessary oxidation stability can be secured, and if it is 700 ppm by mass or less, the base number by hydrolysis of zinc dithiophosphate Can be avoided.

Examples of antioxidants include phenolic antioxidants, ashless antioxidants such as amine antioxidants, and metal antioxidants. Among these, phenol-based antioxidants and / or amine-based antioxidants can be preferably used from the viewpoint of maintaining high-temperature cleaning performance. When the lubricating oil composition of the present invention contains an antioxidant, the content thereof is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, based on the total amount of the composition. In an antioxidant, 0.3 mass% or more is especially preferable, and in a phenolic antioxidant, 0.15 mass% or more is especially preferable. The upper limit of the antioxidant content is not particularly limited, but is preferably 5% by mass or less, more preferably 2% by mass or less, based on the total amount of the composition.

Examples of antifoaming agents include silicone oil, alkenyl succinic acid derivatives, esters of polyhydroxy aliphatic alcohols and long chain fatty acids, methyl salicylate and o-hydroxybenzyl alcohol, aluminum stearate, potassium oleate, N-dialkyl- Allylamine nitroaminoalkanol, aromatic amine salt of isoamyloctyl phosphate, alkylalkylene diphosphate, metal derivative of thioether, metal derivative of disulfide, fluorine compound of aliphatic hydrocarbon, triethylsilane, dichlorosilane, alkylphenyl polyethylene glycol ether sulfide, A fluoroalkyl ether etc. are mentioned. When the antifoaming agent is contained in the lubricating oil composition of the present invention, the content is usually 0.0005 to 1% by mass based on the total amount of the composition, and when the antifoaming agent contains silicon, The amount of Si content in the oil composition is preferably 5 to 50 ppm by mass.

As the pour point depressant, for example, a polymethacrylate polymer compatible with the lubricating base oil to be used can be used. When the lubricating oil composition of the present invention contains a pour point depressant, the content is usually 0.005 to 5% by mass based on the total amount of the composition.

Examples of the metal deactivator include imidazoline, pyrimidine derivatives, alkylthiadiazole, mercaptobenzothiazole, benzotriazole or derivatives thereof, 1,3,4-thiadiazole polysulfide, 1,3,4-thiadiazolyl-2,5-bis. Mention may be made of dialkyldithiocarbamates, 2- (alkyldithio) benzimidazoles, and β- (o-carboxybenzylthio) propiononitrile. When the lubricating oil composition of the present invention contains a metal deactivator, the content is usually 0.005 to 1% by mass based on the total amount of the composition.

As the extreme pressure agent, for example, a sulfur-based, phosphorus-based, sulfur-phosphorus-based extreme pressure agent or the like can be used. Specifically, phosphites, thiophosphites, dithiophosphites, trithiophosphites, phosphate esters, thiophosphate esters, dithiophosphate esters, trithiophosphate esters Examples thereof, amine salts thereof, metal salts thereof, derivatives thereof, dithiocarbamate, zinc dithiocarbamate, molybdenum dithiocarbamate, disulfides, polysulfides, sulfurized olefins, sulfurized fats and oils, and the like. When the extreme pressure agent is contained in the lubricating oil composition of the present invention, the content is not particularly limited, but is usually 0.01 to 5% by mass based on the total amount of the composition.

<Lubricating oil composition>
The base number of the lubricating oil composition of the present invention is 15 to 125 mgKOH / g or more, preferably 20 mgKOH / g or more, more preferably 30 mgKOH / g or more, still more preferably 40 mgKOH / g or more, and preferably 120 mgKOH / g. g or less, more preferably 105 mgKOH / g or less, and still more preferably 100 mgKOH / g or less.
If the base number of the lubricating oil composition is less than 15 mgKOH / g, cleanliness may be insufficient, and if the base number of the lubricating oil composition exceeds 125 mgKOH / g, excessive base components will accumulate on the piston and form an oil film. It is not preferable because it may hinder and cause bore polish or scuffing.

Kinematic viscosity at 100 ° C. of the lubricating oil composition of the present invention is 10 ~ 30mm ² / s, preferably 12 mm ² / s or more, more preferably 12.5 mm ² / s or higher, more preferably 16.3 mm ² / s or more, particularly preferably at 18.0 mm ² / s or more, and preferably not more than 27 mm ² / s, more preferably 26.1 mm ² / s or less, more preferably 21.9 mm ² / s or less, particularly preferably 21.0 mm ² / s or less.
If the kinematic viscosity at 100 ° C. of the lubricating oil composition is less than 10 mm ² / s, the oil film forming ability is insufficient, and the ring and liner may be burned out, which is not preferable. Further, when the kinematic viscosity at 100 ° C. of the lubricating oil composition exceeds 30 mm ² / s, the startability may be deteriorated due to the high viscosity, which is not preferable.

In the second embodiment of the lubricating oil composition of the present invention, the Ph value represented by the following formula (1) is 20 × 10 ⁻³ or less, preferably 19 × 10 ⁻³ or less, more preferably 18 × 10 ⁻³ or less. When the Ph value is less than or equal to the above upper limit, the demulsibility is improved and scum generation in the scrubber can be suppressed.
Ph value = C _Ca × 2 / (r _M × 40.08) (1)
(In Formula (1), C _Ca represents the calcium content (mass%) derived from the component (A1), and r _M represents the metal ratio of the component (A1).)
The calcium content (mass%) derived from the component (A1) here refers to the content of calcium derived from the Ca phenate detergent of the component (A1) in the lubricating oil composition of the present invention. It means a value expressed by mass% based on the total amount of the composition. Further, the metal ratio of the component (A1) here is a value calculated according to the following formula in the Ca phenate-based detergent that is the component (A1).
Metal ratio of component (A1) = Calcium content (% by mass) in Ca phenate detergent as component (A1) / Calcium content derived from soap group in Ca phenate detergent as component (A1) mass%)

<Cylinder lubrication method>
A cylinder lubrication method for a scrubber-mounted crosshead type diesel engine according to a second aspect of the present invention comprises: (i) a cylinder of a crosshead type diesel engine comprising a scrubber with the lubricating oil composition according to the first aspect of the present invention. And (ii) purifying at least a part of the gas discharged from the cylinder with a scrubber.

As a crosshead type diesel engine equipped with a scrubber, a known one can be used without any particular limitation (see, for example, Patent Documents 1 to 5). The method for supplying the lubricating oil composition according to the first aspect of the present invention to the cylinder of the crosshead type diesel engine is not particularly limited, and a known cylinder lubricating oil supply method for the crosshead type diesel engine can be adopted. . The scrubber may be an EGR scrubber, may be a scrubber in a mode of releasing the gas that has passed through the scrubber to the environment without returning it to the suction side, or a combination thereof. However, the scrubber contacts the water introduced into the scrubber with water and / or a basic aqueous solution in that the enhanced demulsibility of the lubricating oil composition according to the first aspect of the present invention is advantageous. It is preferable that the scrubber performs gas purification. As the basic aqueous solution, for example, seawater can be preferably used in addition to an aqueous solution in which a base such as an alkali metal hydroxide or an alkali metal carbonate is dissolved.

Hereinafter, the present invention will be described in more detail based on examples and comparative examples. However, the present invention is not limited to these examples.

<Examples 1 to 11 and Comparative Examples 1 to 7>
For the first embodiment of the lubricating oil composition, lubricating oil compositions having the formulation shown in Tables 1 and 2 were prepared, and a high-speed emulsification test was performed. The results are shown in Tables 1 and 2. In Tables 1 and 2, the amount of the base oil is the content based on the total amount of the base oil, and the amount of the additive is the content based on the total amount of the composition.

(Commercial cylinder oil)
Mineral oil-based base oil 81 mass%, Ca phenate-based detergent in which R ¹ is an alkyl group or alkenyl group having 12 carbons in the above formula (1), carbonic acid Ca sulfonate-based detergent (carbonized 20, 20 and 24 carbon atoms) A hydrogen group bonded to an aromatic six-membered ring), polybutenyl succinimide wherein R ⁴ is a polybutenyl group in the above formula (4), alkyldiphenylamine (the alkyl group has 4 and 8 carbon atoms), alkylphenol, Si compound Contains. The calcium content of commercially available cylinder oil is 2.60% by mass as calcium content based on the total amount of commercially available cylinder oil. The nitrogen content of commercially available cylinder oil is 0.03% by mass as nitrogen content based on the total amount of commercially available cylinder oil.

(Base oil)
Base oil 1: solvent refined base oil, 500 N, 100 ° C. kinematic viscosity 10.8 mm ² / s, saturated content 62 mass%
Base oil 2: solvent refined base oil, bright stock, 100 ° C. kinematic viscosity 31.8 mm ² / s, saturated content 46 mass%

(Metal-based detergent)
Ca phenate: Ca phenate in which A is a sulfide group in the above formula (1), x = 1 to 2, m = 1 to 2, base number 250 mgKOH / g, Ca content 8.9% by mass, metal ratio 4.5 , Sulfur content 3.5% by mass
Ca sulfonate: base number 400 mgKOH / g, Ca content 15.5% by mass, metal ratio 20

(Nitrogen-containing ashless dispersant)
Nitrogen-containing ashless dispersant: in the above formula (4), R ⁴ is a polybutenyl group, n = 5, polyisobutenyl succinimide, N content 1.1 mass%, Mw = 2490, weight average of polybutenyl group part Molecular weight Mw = 1000

(Demulsifier)
B-1: Polypropylene glycol stearyl ether, Mw = 1600
B-2: Polypropylene glycol butyl ether (“New Pole LB-285” manufactured by Sanyo Chemical Industries), Mn = 1170
B-3: Polypropylene glycol butyl ether (“New Paul LB-1715” manufactured by Sanyo Chemical Industries, Ltd.), Mn = 2390
B-4: Ethylene oxide-propylene oxide copolymer, Mw = 4840
Sorbitan monooleate: HLB4.3

<Evaluation method>
(High-speed emulsification test)
This is a model experiment simulating the oil-water separation process after stirring in a scrubber.
40 g of sodium hydroxide aqueous solution (pH = 12) and 10 g of sample oil were collected in a 100 ml graduated cylinder. Set the graduated cylinder on a homogenizer (POLYTRON PT10-35, generator shaft PT36 / 4K, manufactured by KINEMATICA), and stir for 5 minutes at 15,000 rpm, then lift the homogenizer above the graduated cylinder and let it stand for 5 minutes and adhere to the homogenizer. Water, oil and emulsion were collected in a graduated cylinder. The test cylinder after the test was allowed to stand at room temperature for 1 week, and the separability was determined as follows based on the amount of oil separated.
Separated oil volume 10ml: Rating 3,
Separation oil quantity 7.5ml or more and less than 10ml: Rating 2.5
Separation oil amount 5ml or more and less than 7.5ml: Rating 2,
Separation oil amount 1ml or more and less than 5ml
Separation oil amount less than 1 ml: 0 rating
A score of 2 or higher was accepted and a score of 1 or lower was rejected.

<Evaluation results>
The lubricating oil compositions of Examples 1 to 11 showed good separability in the high speed emulsification test (Table 1). (B) the composition of Comparative Example 1 and Comparative Examples 5 to 7 not containing the component, the composition of Comparative Example 2 in which the content of the (B) component was less than 0.02% by mass, and the (B) component Each of the compositions of Comparative Examples 3 to 4 containing a surfactant having no anti-emulsifying action was rated 0 (failed) in the high-speed emulsification test, and was poor in separability (Table 2). . A crosshead type diesel engine was operated using the composition of Comparative Example 1 (that is, commercially available cylinder oil itself) having a score of 0 in the high-speed emulsification test as a cylinder lubricant, and the exhaust gas was washed with a scrubber. Note that the scum was generated in the scrubber.

<Examples 12 to 26, Comparative Examples 8 to 13>
For the second embodiment of the lubricating oil composition of the present invention, lubricating oil compositions having the formulations shown in Tables 3 to 5 were prepared, and a high-speed emulsification test was conducted in the same manner as described above. The results are shown in Tables 3-5. In Tables 3 to 5, the amount of the base oil is the content based on the total amount of the base oil, and the amount of the additive is the content based on the total amount of the composition.

((A1) component)
(A1) -1: Ca phenate in which A is a sulfide group in the above formula (1), x = 1 to 2, m = 1 to 2, base number 250 mgKOH / g, Ca content 8.9% by mass, metal ratio 4.5, sulfur content 3.5% by mass
(A1) -2: In the above formula (1), A is a sulfide group, Ca phenate with x = 1 to 3, m = 1 to 4, base number 150 mgKOH / g, Ca content 5.4% by mass, metal ratio 2.7, sulfur content 4.1% by mass
(A1) -3: Ca phenate in which A is a methylene group, x = 1 to 3, m = 1 to 4 in the above formula (1), base number 70 mgKOH / g, Ca content 2.5% by mass, metal ratio 1.3

((A2) component)
(A2) -1: Ca sulfonate, base number 400 mgKOH / g, Ca content 15.5% by mass, metal ratio 20
(A2) -2: In the above formula (2), M is calcium, R ² is an alkyl group derived from an α-olefin having 14 to 18 carbon atoms, Ca salicylate with n = 1 to 2, base number 225 mgKOH / g, containing Ca Amount 8.2% by mass, metal ratio 3.1

((C-1 ′) component)
(C-1 ′)-1: R ⁴ is a polybutenyl group in the above formula (4), polyisobutenyl succinimide in which n = 5, bistype, N content 1.1 mass%, Mw = 2490, Weight average molecular weight of polybutenyl group moiety Mw = 1000
(C-1 ′)-2: Polyisobutenyl succinimide in which R ³ is a polybutenyl group and n = 4 in the above formula (3), monotype, N content 2.0 mass%, Mw = 1000

<Evaluation results>
The lubricating oil compositions of Examples 12 to 26 showed good separability in the high speed emulsification test (Tables 1 and 2). The lubricating oil compositions of Examples 24 to 26 exhibited sufficient demulsibility even when the component (C) acting as a dispersant was contained in an amount of 0.015% by mass or less based on the total amount of the composition. . The compositions of Comparative Examples 8 to 10 having a Ph value exceeding 20 × 10 ⁻³ had a rating of 0 (failed) in the high-speed emulsification test, and were inferior in separability. In addition, the compositions of Comparative Examples 11 to 13 in which the content of the component (C) exceeds 0.015% by mass as the nitrogen content based on the total amount of the composition, although the Ph value is 20 × 10 ⁻³ or less, In the high-speed emulsification test, all scored 0 (failed) and was inferior in separability.

Claims

Containing a base oil, and (A) a metallic detergent,
The base number is 15 to 125 mg KOH / g,
The kinematic viscosity at 100 ° C. is 10 to 30 mm 2 / s,
A cylinder lubricant composition for a scrubber-mounted crosshead diesel engine that satisfies the following requirement (i) or (ii):
(I) Based on the total amount of the lubricating oil composition (B) 0.02 to 5.0% by mass of demulsifier
Containing;
(Ii) As the component (A),
(A1) Ca phenate detergent, and
(A2) contains a metallic detergent other than the Ca phenate detergent,
(C-1 ′) A succinimide having at least one alkyl group or alkenyl group in the molecule or a boronated derivative thereof is contained or contained in an amount of 0.015% by mass or less based on the total amount of the composition. Without
The Ph value represented by the following formula (1) is 20 × 10 −3 or less.
Ph value = C Ca × 2 / (r M × 40.08) (1)
(In formula (1), C Ca represents the calcium content (mass%) derived from the component (A1), and r M represents the metal ratio of the component (A1).)
Meets the requirements of (i) above,
The cylinder lubricating oil composition for a scrubber-mounted crosshead diesel engine according to claim 1, further comprising (C) a nitrogen-containing ashless dispersant.
Meets the requirements of (i) above,
The cylinder for a scrubber-mounted crosshead type diesel engine according to claim 1, wherein (C) the nitrogen-containing ashless dispersant is contained or not contained in an amount of 0.2% by mass or less as a nitrogen content based on the total amount of the lubricating oil composition. Lubricating oil composition.
Meets the requirements of (i) above,
The cylinder lubricant composition for a scrubber-mounted crosshead type diesel engine according to any one of claims 1 to 3, wherein the component (B) is one or more polyether compounds.
The cylinder lubricant composition for a scrubber-mounted crosshead type diesel engine according to claim 4, wherein the number average molecular weight of the component (B) is 500 or more.
Meets the requirements of (i) above,
The cylinder lubricant composition for a scrubber-mounted crosshead type diesel engine according to any one of claims 1 to 5, wherein the metal detergent (A) is Ca phenate.
Meet the requirement (ii) above,
The succinimide having at least one (C-1 ′) alkyl group or alkenyl group in the molecule or a boronated derivative thereof is contained in an amount of more than 0% by mass and 0.015% by mass or less based on the total amount of the composition. ,
The cylinder lubricating oil composition for a scrubber-mounted crosshead type diesel engine according to claim 1.
Meet the requirement (ii) above,
The component (A2) is Ca sulfonate and / or Ca salicylate.
The cylinder lubricating oil composition for a scrubber-mounted crosshead type diesel engine according to claim 1 or 7.
A step of operating the crosshead type diesel engine while supplying the lubricating oil composition according to any one of claims 1 to 8 to a cylinder of the crosshead type diesel engine provided with a scrubber; and
A cylinder lubrication method for a scrubber-mounted crosshead type diesel engine, comprising a step of purifying at least a part of the gas discharged from the cylinder in the scrubber.
The purification in the scrubber includes a step of bringing a gas introduced into the scrubber into contact with water and / or a basic aqueous solution.
A cylinder lubrication method for a scrubber-mounted crosshead diesel engine according to claim 9.