Marine diesel cylinder lubricating oil composition

Abstract

To provide a lubricating oil composition.SOLUTION: Disclosed is a marine diesel cylinder lubricating oil composition which comprises (a) a major amount of an oil of lubricating viscosity, and (b) one or more non-borated polyalkenyl bis-succinimide dispersants, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about (1,500) to about (3,000), the marine diesel cylinder lubricating oil composition also having a total base number (TBN) of about (5) to about (150). Also disclosed is a marine diesel cylinder lubricating oil composition which comprises (a) a major amount of an oil of lubricating viscosity, and (b) one or more cyclic carbonate post-treated polyalkenyl bis-succinimide dispersants, wherein the marine diesel cylinder lubricating oil composition has a total base number (TBN) of about (5) to about (150).SELECTED DRAWING: None

Description

Technical Field

[0001] Background of the Invention 1. Technical Field The present invention generally relates to a diesel cylinder lubricant composition for ships, and more particularly to a lubricant composition for lubricating a two-stroke crosshead diesel cylinder engine for ships.

Background Art

[0002] 2. Description of Related Art Not so long ago, rapidly rising energy costs, especially the costs incurred in distilling crude oil and liquid petroleum, have become a heavy burden on users of transportation fuels such as owners and operators of ocean-going ships. In response, those users have moved away from steam turbine propulsion units and have taken the helm of their operations by supporting larger diesel engines with higher fuel efficiency. Diesel engines can generally be classified into low-speed, medium-speed, or high-speed engines, and the low-speed type is used for the largest deep-shaft ships and certain other industrial applications.

[0003] Low-speed diesel engines are unique in terms of size and operating method. The engines themselves are large-scale, and in larger units, the weight can be nearly 200 tons, and the length can exceed 10 feet and the height can exceed 45 feet. The output of these engines can reach up to 100,000 brake horsepower, and the engine speed is 60 to about 200 revolutions per minute. They are typically of crosshead design and operate on a two-stroke cycle. These engines typically operate on residual fuel, but some can also operate on distillate fuel that contains little or no residue.

[0004] On the one hand, medium-speed engines typically operate in the range of about 250 to about 1100 rpm and can operate on either a four-stroke or two-stroke cycle. These engines can be of trunk piston design or sometimes crosshead design. They typically operate on residual fuel, much like low-speed diesel engines, but some can operate on distillate fuel that contains little or no residue. Further, these engines can also be used for propulsion of deep-sea vessels, auxiliary applications, or both.

[0005] Low- and medium-speed diesel engines are also widely used in the operation of power plants. Low- or medium-speed diesel engines operating on a two-stroke cycle are typically crosshead-structured direct-connected and direct-reversing engines, which are provided with one or more stuffing boxes and diaphragms that separate the power cylinders from the crankcase, thereby preventing combustion products from entering the crankcase and mixing with the crankcase oil. By highly and completely separating the crankcase from the combustion zone, those skilled in the art have come to lubricate the combustion chamber and the crankcase with different lubricating oils.

[0006] In large crosshead-type diesel engines used in marine applications and heavy stationary applications, the cylinders are lubricated separately from the other engine components. The cylinders are lubricated on a total loss basis by separately injecting cylinder oil into the quills of each cylinder using a lubrication device arranged around the cylinder liner. The oil is distributed to the lubrication device using a pump and, in current engine designs, is directed to coat the rings directly to reduce oil waste.

[0007] One problem associated with these engines is that engine manufacturers typically design them to use a variety of diesel fuels ranging from high-quality high-distillate fuels with low sulfur and low asphaltene content to poorer-quality intermediate or heavy fuels such as marine residual fuels with high sulfur and higher asphaltene content.

[0008] Due to the high stresses encountered in these engines and the use of marine residual fuels, even if the oil is only exposed to heat and other stresses for a short time, lubricants are needed that have high cleanliness, neutralizing capacity, and better stability against viscosity increase due to oxidation. The residual fuels commonly used in these diesel engines typically contain significant amounts of sulfur, which, in the combustion process, combines with water to form sulfuric acid, and if present, causes corrosive wear. In particular, in marine two-stroke engines, the areas around the cylinder liners and piston rings can be corroded and worn by the acid. Therefore, it is important for diesel engine lubricating oils to have the ability to counter such corrosion and wear.

[0009] Therefore, one of the main functions of a marine diesel cylinder lubricant is to neutralize the acidic components resulting from the sulfur in the high-sulfur fuel oil burned in low-speed two-stroke crosshead diesel engines. This neutralization is achieved by including basic species such as metal detergents in the marine diesel cylinder lubricant. Unfortunately, the base number of the marine diesel cylinder lubricant can be reduced by the oxidation of the marine diesel cylinder lubricant (due to the heat and oxidative stress the lubricant undergoes in the engine), thereby reducing the neutralizing capacity of the lubricant. Therefore, oxidation stability is one of the important performance aspects of marine cylinder lubricants. Oxidation can be promoted if the marine diesel cylinder lubricant contains oxidation catalysts such as wear metals that are generally known to be present in the lubricant during engine operation.

[0010] Typically, a marine cylinder lubricant for use in a marine diesel engine has a viscosity in the range of 9.3 to 26.1 centistokes (cSt) at 100°C. To formulate such a lubricant, bright stock can be mixed with a low-viscosity oil, such as an oil having a viscosity of 4 to 6 cSt at 100°C. However, since the supply of bright stock is decreasing, it is not possible to use bright stock to raise the viscosity of the marine cylinder lubricant to the range of 16.5 to 25 cSt at 100°C recommended by the manufacturer. Additionally, Hart’s Lubricant World, September 1997, pages 27 - 28 (see European Patent No. 1967571) discloses that “due to the low operating speed and high load of marine engines, high-viscosity oils (SAE 40, 50 and 60) are typically required. Since the viscosity of the base stock is lost by hydrocracking, marine oils generally need to be formulated not only with hydrocracked base stocks but also with significant amounts of bright stock in some cases. However, the use of bright stock is undesirable because of the presence of oxidatively unstable aromatic compounds.”

[0011] One solution to this problem is to thicken the marine cylinder lubricant using a thickening agent such as polyisobutylene or a viscosity index improver compound such as an olefin copolymer. However, these materials increase the cost of the marine cylinder lubricant. Another solution is to use a lower-viscosity marine cylinder lubricant, but the wear performance of low-viscosity MCL has not been well studied.

[0012] Another important performance aspect of cylinder lubricants for ships is their foaming performance. When a large amount of gas mixes into a liquid, it foams. Foaming is desirable for certain applications such as floating, washing, and cleaning. However, foaming can be a hindrance in lubricant-related applications where it can eliminate the lubricating effect. The viscosity and surface tension of a lubricant contribute to the stability of the foam. Low-viscosity oils produce bubbles with large air bubbles, which tend to break down rapidly and thus are rarely a problem. However, high-viscosity oils such as those used as cylinder lubricants for ships contain fine air bubbles and produce stable bubbles that are difficult to break down. In the case of cylinder lubricants for ships, foaming can disrupt the lubricant film that keeps the piston ring and cylinder liner surfaces separated. Over time, foaming can accelerate the oxidative degradation of the lubricant and, in addition, can affect the oil's transport and pumping capabilities. Therefore, in the case of cylinder lubricants for ships, foaming specifications are often included in product performance.

[0013] U.S. Patent No. 6,103,672 (the " '672 Patent") discloses a cylinder lubricant for ships that contains a major amount of an oil of lubricating viscosity, as well as minor amounts of a) at least one borated dispersant or an oil-soluble or oil-dispersible boron compound and b) one or more overbased metal compounds (provided in combination) and does not contain polybutene. Further, the '672 Patent discloses that the viscosity characteristics of the cylinder lubricant for ships that does not contain polybutene have been improved.

[0014] U.S. Patent No. 4,948,522 (the " '522 Patent") discloses a diesel cylinder lubricant for ships that contains a borated ashless dispersant, an overbased metal compound, and polybutene having a weight average molecular weight of over 100,000. Further, the '522 Patent discloses the provision of a diesel cylinder lubricant for ships that exhibits increased oxidation, wear, and deposits.

[0015] U.S. Patent Application Publication No. 2005 / 0153847 discloses a marine diesel cylinder lubricant composition comprising an oil having a total base number of at least 30 and containing (a) at least 40% by mass of an oil having lubricating viscosity, (b) a detergent prepared from at least two surfactants, (c) a boron-containing dispersant, and (d) a zinc-containing antiwear additive.

[0016] International Publication No. 2011 / 051261 pamphlet discloses and teaches a lubricating composition used in internal combustion engines operating under continuous high load conditions such as marine diesel engines and power generation applications, comprising a base oil and a combination of sulfonates and phenate detergents. In the examples disclosed in International Publication No. 2011 / 051261 pamphlet, a high molecular weight polyisobutene succinimide is used at a concentration of 1.5% by weight of the composition.

Summary of the Invention

Problems to be Solved by the Invention

[0017] Therefore, there remains a need for an improved marine diesel cylinder lubricating oil composition having improved oxidation stability and foam suppression, which can further reduce the amount of bright stock used in the lubricating oil composition.

Means for Solving the Problems

[0018] Summary of the Invention According to one embodiment of the present invention, there is provided a marine diesel cylinder lubricating oil composition comprising (a) a major amount of an oil having lubricating viscosity and (b) one or more non-boronated polyalkenyl bis-succinimide dispersants, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, and further wherein the marine diesel cylinder lubricating oil composition has a total base number (TBN) of from about 5 to about 150.

[0019] A method of lubricating a marine two-stroke crosshead diesel engine in accordance with a second embodiment of the present invention, using a marine diesel cylinder lubricant composition having improved oxidation stability, the method comprising operating the engine with a marine diesel cylinder lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity and (b) one or more non-boronated polyalkenyl bis succinimide dispersants, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, and further wherein the marine diesel cylinder lubricating oil composition has a total base number (TBN) of from about 5 to about 150.

[0020] In accordance with a third embodiment of the present invention, there is provided a marine diesel cylinder lubricating oil composition for use in a two-stroke crosshead marine diesel engine having improved oxidation stability, the lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity, the marine diesel cylinder lubricating oil composition having a total base number (TBN) of from about 5 to about 150, and (b) one or more non-boronated polyalkenyl bis succinimide dispersants, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000.

[0021] In accordance with a fourth embodiment of the present invention, there is provided a marine diesel cylinder lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity and (b) a polyalkenyl bis succinimide dispersant post-treated with one or more cyclic carbonates, the marine diesel cylinder lubricating oil composition having a total base number (TBN) of from about 5 to about 150.

[0022] A method of lubricating a marine two-stroke crosshead diesel engine according to a fifth embodiment of the present invention, using a marine diesel cylinder lubricant composition having improved oxidation stability, the method comprising operating the engine with a marine diesel cylinder lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity and (b) one or more cyclic carbonate post-treated polyalkenyl bis succinimide dispersants, the marine diesel cylinder lubricating oil composition having a total base number (TBN) of from about 5 to about 150.

[0023] According to a sixth embodiment of the present invention, to provide a marine diesel cylinder lubricating oil composition having improved oxidation stability for a two-stroke crosshead marine diesel engine, there is provided the use of a polyalkenyl bis succinimide dispersant post-treated with one or more cyclic carbonates in a marine diesel cylinder lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity, the marine diesel cylinder lubricating oil composition having a total base number (TBN) of from about 5 to about 150.

[0024] The present invention relates to a marine diesel cylinder lubricating oil composition for use in a two-stroke crosshead marine diesel engine, which is either a non-boronated polyalkenyl bis-succinimide dispersant wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, or a cyclic carbonate post-treated polyalkenyl bis-succinimide dispersant. Based on the surprising discovery that the oxidation stability of said composition is advantageously improved when the marine diesel cylinder lubricant has a TBN of from about 5 to about 150. Additionally, foaming of a marine diesel cylinder lubricating oil composition having a TBN of from about 5 to about 150 is more advantageously suppressed by either the dispersant which is a non-boronated polyalkenyl bis-succinimide dispersant wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, or a cyclic carbonate post-treated polyalkenyl bis-succinimide dispersant. Further, by using either the dispersant which is a non-boronated polyalkenyl bis-succinimide dispersant wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, or a cyclic carbonate post-treated polyalkenyl bis-succinimide dispersant, it is possible to advantageously reduce the amount of bright stock when formulating a marine diesel cylinder lubricating oil composition having a TBN of from about 5 to about 150.

DETAILED DESCRIPTION OF THE INVENTION

[0025] Detailed Description of Preferred Embodiments Definitions

[0026] As used herein, the terms "marine diesel cylinder lubricant" or "marine diesel cylinder oil" are understood to mean lubricants used for lubricating the cylinders of slow or medium speed two-stroke crosshead marine diesel engines. Marine diesel cylinder lubricants are supplied to the cylinder walls through a number of injection points. Marine diesel cylinder lubricants promote engine cleanliness by forming a film between the cylinder liner and the piston rings and by holding partially burned fuel residues in suspension, and can neutralize acids formed, for example, by the combustion of sulfur compounds in the fuel.

[0027] "Marine residual fuel" means a combustible material in large marine engines having a carbon residue of at least 2.5 wt% (e.g., at least 5 wt%, or at least 8 wt%) (based on the total weight of the fuel), a viscosity higher than 14.0 cSt at 50°C, such as marine residual fuels defined in the International Organization for Standardization (ISO) standard ISO 8217:2005, "Petroleum Products - Fuels (class F) - Specifications of marine fuels", the entire content of which is incorporated herein by reference.

[0028] "Residual fuel" means a fuel conforming to the specifications of residual marine fuels as defined in the ISO 8217:2010 international standard. "Low sulfur marine fuel" means a fuel conforming to the specifications of residual marine fuels as defined in the ISO 8217:2010 specifications and, in addition, having sulfur of about 1.5 wt% or less, or even about 0.5 wt% or less, based on the total weight of the fuel.

[0029] "Distillate fuel" means a fuel conforming to the specifications of distillate marine fuels as defined in the ISO 8217:2010 international standard. "Low sulfur distillate fuel" means a fuel conforming to the specifications of distillate marine fuels as defined in the ISO 8217:2010 international standard and, in addition, having sulfur of about 0.1 wt% or less, or even about 0.005 wt% or less, based on the total weight of the fuel.

[0030] The term "bright stock" as used by those skilled in the art means a base oil derived from deasphalted petroleum vacuum residue after further processing such as solvent extraction and / or dewaxing, or a base oil that is a direct product of deasphalted petroleum vacuum residue. For the purposes of the present invention, it also means the deasphalted distillate cut of the vacuum residue process. Bright stock generally has a kinematic viscosity of 28 to 36 mm 2 / s at 100°C. An example of such bright stock is ESSO (trademark) Core2500 Base Oil.

[0031] The term "succinimide", including alkenyl or alkyl mono-, bis-succinimides and other higher analogues, is generally accepted to mean the reaction product of an alkenyl-substituted succinic acid or anhydride and a polyamine.

[0032] The term "bis-succinimide" represents a succinimide dispersant that is mainly bis-succinimide. Dispersants that are mainly bis-succinimide contain a major amount of bis-succinimide compared to other compounds such as monosuccinimide that may be present in the succinimide dispersant. A succinimide dispersant containing a mixture of compounds including monosuccinimide and bis-succinimide is obtained from the reaction product of a hydrocarbyl-substituted succinic acid acylating agent and an alkylene polyamine. The amounts of monoalkenyl succinimide and bisalkenyl succinimide produced can depend on the charge molar ratio of alkylene polyamine to succinic acid groups and the specific polyamine used. From a charge molar ratio of alkylene polyamine to succinic acid groups of about 1:1, a dispersant that is mainly mono-succinimide can be obtained. From a charge molar ratio of alkylene polyamine to succinic acid groups of about 1:2, a dispersant that is mainly bis-succinimide can be obtained.

[0033] The term "Group II metal" or "alkaline earth metal" means calcium, barium, magnesium and strontium.

[0034] The term "calcium base" means calcium hydroxide, calcium oxide, calcium alkoxide, etc. and mixtures thereof.

[0035] The term "lime" means calcium hydroxide, also known as slaked lime or hydrated lime.

[0036] The term "alkylphenol" means a phenol group having one or more alkyl substituents, at least one of which has a sufficient number of carbon atoms to impart oil solubility to the resulting phenate additive.

[0037] The term "total base number" or "TBN" means the level of alkalinity in an oil sample, which indicates the ability of a composition to continue to neutralize corrosive acids according to ASTM standard number D2896 or an equivalent procedure. The test measures the change in electrical conductivity and expresses the result as mg·KOH / g (the milligram equivalent number of KOH required to neutralize 1 gram of the product). Thus, a high TBN represents a strong overbased product and, as a result, a higher base reserve for neutralizing acids.

[0038] The term "base oil" as used herein is understood to mean a base stock or blend of base stocks that are manufactured to the same specifications (regardless of source or manufacturer location) by a single manufacturer; conform to the same manufacturer's specifications; and are identified by their unique formulation, product identification number, or both.

[0039] The term "on an active basis" means an additive material that is neither a diluent oil nor a solvent.

[0040] In one embodiment, there is provided a marine diesel cylinder lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity and (b) a non-phosphorus polyalkenyl bis succinimide dispersant, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, and the marine diesel cylinder lubricating oil composition has a total base number (TBN) of from about 5 to about 150.

[0041] The marine diesel cylinder lubricating oil composition of the present invention can have any TBN suitable for use as a marine cylinder lubricant. In some embodiments, the TBN of the marine diesel cylinder lubricating oil composition of the present invention is less than about 150 mg·KOH / g. In other embodiments, the TBN of the marine diesel cylinder lubricating oil composition of the present invention can range from about 5 to about 150, or from about 5 to about 100, or from about 5 to about 70, or from about 5 to about 30, or from about 5 to about 25, or from about 10 to about 150, or from about 10 to about 70, or from about 10 to about 40, or from about 10 to about 30, or from about 15 to about 150, or from about 15 to about 100, or from about 15 to about 70, or from about 15 to about 30, or from about 15 to about 40, or from about 20 to about 150, or from about 20 to about 100, or from about 20 to about 70, or from about 20 to about 40, or from about 20 to about 30 mgKOH / g.

[0042] Due to the low operating speeds and high loads of marine engines, high viscosity oils (SAE 40, 50, and 60) are typically required. The marine diesel cylinder lubricating oil composition of the present invention can have a kinematic viscosity in the range of from about 12.5 to about 26.1 cSt, or from about 12.5 to about 21.9, or from about 16.3 to about 21.9 cSt at 100 °C. The kinematic viscosity of the marine diesel cylinder lubricating oil composition is measured by ASTM D445.

[0043] The marine diesel cylinder lubricant composition of the present invention can be prepared by any method known to those skilled in the art for manufacturing a marine diesel cylinder lubricant composition. The components can be added in any order and by any method. Any suitable mixing or dispersing device can be used to blend, mix or solubilize the components. Blending, mixing or solubilizing can be carried out using a blender, stirrer, disperser, mixer (e.g., planetary mixer and double planetary mixer), homogenizer (e.g., Gaulin homogenizer or Rannie homogenizer), mill (e.g., colloid mill, ball mill or sand mill) or any other mixing or dispersing device known in the art.

[0044] The marine diesel cylinder lubricant composition of the present invention contains a major amount of an oil of lubricating viscosity. "Major amount" means that the marine diesel cylinder lubricant composition preferably contains at least about 40% by weight, or at least about 50% by weight, or at least about 60% by weight, particularly at least about 70% by weight, of an oil of lubricating viscosity as described below, based on the total weight of the marine diesel cylinder lubricant composition. In one embodiment, the oil of lubricating viscosity is present in an amount of from 70% to about 95% by weight based on the total weight of the marine diesel cylinder lubricant composition. In one embodiment, the oil of lubricating viscosity is present in an amount of from 70% to about 85% by weight based on the total weight of the marine diesel cylinder lubricant composition.

[0045] The oil of lubricating viscosity can be any oil suitable for lubricating a large diesel engine including, for example, a crosshead engine. The oil of lubricating viscosity can be a base oil derived from natural lubricating oils, synthetic lubricating oils or mixtures thereof. Suitable base oils include base stocks obtained by isomerization of synthetic waxes and slack waxes, and hydrocracked base oils produced by hydrocracking (not solvent extraction) of the aromatic and polar components of crude oil.

[0046] Suitable natural oils include, for example, mineral lubricating oils such as liquid petroleum, solvent-treated or acid-treated mineral lubricating oils of paraffinic, naphthenic or mixed paraffinic-naphthenic types, oils derived from coal or shale, animal oils, vegetable oils (e.g., rapeseed oil, castor oil and lard oil), and the like.

[0047] Suitable synthetic lubricating oils include, without limitation, hydrocarbon oils and halo-substituted hydrocarbon oils, such as polymerized and interpolymerized olefins, such as polybutylene, polypropylene, propylene-isobutylene copolymers, chlorinated polybutylene, poly(1-hexene), poly(1-octene), poly(1-decene), etc. and mixtures thereof; alkylbenzenes, such as dodecylbenzene, tetradecylbenzene, dinonylbenzene, di(2-ethylhexyl)-benzene, etc.; polyphenyls, such as biphenyl, terphenyl, alkylated polyphenyls, etc.; alkylated diphenyl ethers and alkylated diphenyl sulfides and their derivatives, analogs and homologs, and the like.

[0048] Other synthetic lubricating oils include, without limitation, oils made by polymerizing olefins having less than 5 carbon atoms, such as ethylene, propylene, butylene, isobutene, pentene, and mixtures thereof. Methods for preparing such polymer oils are well known to those skilled in the art.

[0049] Additional synthetic hydrocarbon oils include liquid polymers of alpha olefins having suitable viscosities. Particularly useful synthetic hydrocarbon oils are hydrogenated liquid oligomers of C 6 to C 12 alpha olefins, such as 1-decene trimer.

[0050] Another type of synthetic lubricating oil includes, without limitation, alkylene oxide polymers, i.e., homopolymers, interpolymers, and derivatives thereof in which the terminal hydroxyl groups are modified, for example, by esterification or etherification. Examples of these oils include oils prepared by polymerization of ethylene oxide or propylene oxide, alkyl and phenyl ethers of these polyoxyalkylene polymers (e.g., methyl polypropylene glycol ether with an average molecular weight of 1,000, diphenyl ether of polyethylene glycol with a molecular weight of 500 to 1,000, diethyl ether of polypropylene glycol with a molecular weight of 1,000 to 1,500, etc.) or their mono- and polycarboxylic acid esters, such as acetic acid esters, mixed C 3 from C 8 fatty acid esters, or C 13 oxo acid diesters of tetraethylene glycol, etc.

[0051] Yet another type of synthetic lubricating oil includes, without limitation, esters of dicarboxylic acids such as phthalic acid, succinic acid, alkyl succinic acid, alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acid, alkenyl malonic acid, etc. and various alcohols such as butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol, etc. Specific examples of these esters include dibutyl adipate, bis(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, 2-ethylhexyl diester of linoleic acid dimer, and complex esters formed by the reaction of 1 mole of sebacic acid with 2 moles of tetraethylene glycol and 2 moles of 2-ethylhexanoic acid, etc.

[0052] Esters useful as synthetic oils include, without limitation, those made from carboxylic acids having from about 5 to about 12 carbon atoms and alcohols such as methanol, ethanol, etc., polyols and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, etc.

[0053] Silicone oils such as polyalkyl-, polyaryl-, polyalkoxy- or polyaryloxy-siloxane oils and silicate oils, etc., include another useful type of synthetic lubricating oil. Specific examples of these include, without limitation, tetraethyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl) silicate, tetra-(4-methyl-hexyl) silicate, tetra-(p-tert-butylphenyl) silicate, hexyl-(4-methyl-2-pentoxy) disiloxane, poly(methyl) siloxane, poly(methylphenyl) siloxane, etc. Still other useful synthetic lubricating oils include, without limitation, liquid esters of phosphorus-containing acids such as tricresyl phosphate, trioctyl phosphate, diethyl ester of decanephosphonic acid, etc., polymeric tetrahydrofuran, etc.

[0054] Lubricating viscosity oils can be derived from natural or synthetic unrefined, refined, and re-refined oils, or mixtures of any two or more of the foregoing types. Unrefined oils are those obtained directly from natural or synthetic sources (e.g., coal, shale, or tar sand bitumen) without further refining or treatment. Examples of unrefined oils include, but are not limited to, shale oil obtained directly from retorting operations, petroleum obtained directly from distillation, or ester oils obtained directly from an esterification process, each of which is then used without further treatment. Refined oils are similar to unrefined oils except that they have been further processed in one or more refining steps to improve one or more properties. These refining techniques are known to those skilled in the art and include, for example, solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, hydrorefining, dewaxing, etc. Re-refined oils are obtained by treating used oils in a process similar to that used to obtain refined oils. Such re-refined oils are also known as regenerated or reprocessed oils and are often additionally treated by techniques aimed at removing used additives and oil decomposition products.

[0055] Furthermore, lubricating oil base stocks derived from the hydroisomerization of wax can be used alone or in combination with the natural and / or synthetic base stocks. Such wax isomerate oils are produced by the hydroisomerization of natural or synthetic wax or mixtures thereof over a hydroisomerization catalyst.

[0056] Natural wax is typically slack wax recovered by solvent dewaxing of mineral oil. Synthetic wax is typically wax produced by the Fischer-Tropsch process.

[0057] In one embodiment, the lubricating viscosity oil is a Group I base stock. Generally, the Group I base stock for use herein can be a petroleum-derived lubricating base oil having a lubricating viscosity as defined in API Publication 1509, 16th Edition, Addendum I, October 2009. The API guidelines define base stocks as lubricant components that can be manufactured using a variety of different processes. Group I base oils generally mean petroleum-derived lubricating base oils having a saturates content of less than 90 wt% (quantified by ASTM D2007) and / or a total sulfur content of more than 300 ppm (quantified by ASTM D2622, ASTM D4294, ASTM D4297 or ASTM D3120), and a viscosity index (VI) of 80 or more and less than 120 (quantified by ASTM D2270).

[0058] Group I base oils can include light overhead cuts and heavier side cuts from a vacuum distillation column, and can further include, for example, light neutral, medium neutral and heavy neutral base stocks. Further, the petroleum-derived lubricating base oil can include, for example, a residue stock or bottom fraction such as bright stock. Bright stock is a high-viscosity base oil that has been conventionally manufactured from residual stock or bottoms and has been highly refined and dewaxed. Bright stock can have a kinematic viscosity at 40 °C of more than about 180 cSt, or more than about 250 cSt, or in the range of about 500 to about 1100 cSt at 40 °C.

[0059] In one embodiment, the one or more base stocks can be a blend or mixture of two or more, three or more, or even four or more Group I base stocks having different molecular weights and viscosities, in which case the blend is processed in a manner suitable for making a base oil having suitable properties (such as the viscosities and TBN values discussed above) for use in marine diesel engines. In one embodiment, the one or more base stocks include ExxonMobil CORE™ 100, ExxonMobil CORE™ 150, ExxonMobil CORE™ 600, ExxonMobil CORE™ 2500, or a combination or mixture thereof.

[0060] In another embodiment, the lubricating viscosity oil can be a Group II base stock as defined in API Publication 1509, 16th Edition, Addendum I, October 2009. Group II base stocks generally mean petroleum-derived lubricating base oils having a total sulfur content of 300 ppm (parts per million) or less (quantified by ASTM D2622, ASTM D4294, ASTM D4297, or ASTM D3120), a saturates content of 90 wt% or more (quantified by ASTM D2007), and a viscosity index (VI) of 80 to 120 (quantified by ASTM D2270).

[0061] In another embodiment, the lubricating viscosity oil can be a Group III base stock as defined in API Publication 1509, 16th Edition, Addendum I, October 2009. Group III base stocks generally have a total sulfur content of 0.03 wt% or less (quantified by ASTM D2270), a saturates content of 90 wt% or more (quantified by ASTM D2007), and a viscosity index (VI) of 120 or more (quantified by ASTM D4294, ASTM D4297, or ASTM D3120). In one embodiment, the base stock is a Group III base stock or a blend of two or more different Group III base stocks.

[0062] Generally, Group III base stocks derived from petroleum oils are highly hydrotreated mineral oils. Hydrotreating involves reacting hydrogen with the base stock to be treated to remove heteroatoms from hydrocarbons, reducing olefins and aromatic compounds to alkanes and cycloparaffins respectively, and in very high levels of hydrotreating, ring-opening of naphthenic ring structures to acyclic normal and isoalkanes (“paraffins”). In one embodiment, the Group III base stock has a paraffinic carbon content (%C p ) of at least about 70%, which is quantified by the test method ASTM D3238-95(2005), “Standard Test Method for Calculation of Carbon Distribution and Structural Group Analysis of Petroleum Oils by the n-d-M Method”. In another embodiment, the Group III base stock has a paraffinic carbon content (%C p ) of at least about 72%. In another embodiment, the Group III base stock has a paraffinic carbon content (%C p ) of at least about 75%. In another embodiment, the Group III base stock has a paraffinic carbon content (%C p ) of at least about 78%. In another embodiment, the Group III base stock has a paraffinic carbon content (%C p ) of at least about 80%. In another embodiment, the Group III base stock has a paraffinic carbon content (%C p ) of at least about 85%.

[0063] In another embodiment, the Group III base stock has a naphthenic carbon content (%C n ) of about 25% or less, which is quantified by ASTM D3238-95(2005). In another embodiment, the Group III base stock has a naphthenic carbon content (%C n) has. In another embodiment, the Group III base stock has a naphthenic carbon content of about 15% or less (%C n ) has. In another embodiment, the Group III base stock has a naphthenic carbon content of about 10% or less (%C n ).

[0064] Many of the Group III base stocks are commercially available, for example, Chevron UCBO base stock; Yukong Yubase base stock; Shell XHVI® base stock; and ExxonMobil Exxsyn® base stock.

[0065] In one embodiment, the Group III base stock for use herein is a Fischer-Tropsch derived base oil. The term "Fischer-Tropsch derived" means that the product, fraction, or feed results from, or is produced at some stage by, the Fischer-Tropsch process. For example, Fischer-Tropsch base oils can be produced from a process where the feed is a waxy feed recovered from Fischer-Tropsch synthesis, see, e.g., U.S. Patent Application Publication Nos. 2004 / 0159582; 2005 / 0077208; 2005 / 0133407; 2005 / 0133409; 2005 / 0139513; 2005 / 0139514; 2005 / 0241990; 2005 / 0261145; 2005 / 0261146; 2005 / 0261147; 2006 / 0016721; 2006 / 0016724; 2006 / 0076267; 2006 / 013210; 2006 / 0201851; 2006 / 020185; and 2006 / 0289337; U.S. Pat. Nos. 7,018,525 and 7,083,713 and U.S. Application Nos. 11 / 400570; 11 / 535165; and 11 / 613936, each of which is incorporated herein by reference. Generally, the process includes a complete or partial hydroisomerization dewaxing step that utilizes a catalyst or bifunctional catalyst capable of selectively isomerizing paraffins. Hydroisomerization dewaxing is accomplished by contacting the waxy feed with a hydroisomerization catalyst under hydroisomerization conditions in an isomerization zone.

[0066] The products of Fischer-Tropsch synthesis can be obtained, for example, by well-known processes such as the commercial SASOL® Slurry Phase Fischer-Tropsch technology, the commercial SHELL® Middle Distillate Synthesis (SMDS) process, or the non-commercial EXXON® Advanced Gas Conversion (AGC-21) process. These processes and other details are described, for example, in International Publication No. 9934917; International Publication No. 9920720; International Publication No. 05107935; European Patent Application Publication No. 776959; European Patent Application Publication No. 668342; U.S. Patent Nos. 4,943,672, 5,059,299; 5,733,839; and U.S. Reissue Patent No. 39073; and U.S. Patent Application Publication No. 2005 / 0227866. The products of Fischer-Tropsch synthesis can contain hydrocarbons having from 1 to about 100 carbon atoms, and in some cases more than 100 carbon atoms, and typically include paraffins, olefins, and oxygen-containing products.

[0067] In another embodiment, the lubricating viscosity oil can be a Group IV base stock as defined in API Publication 1509, 16th Edition, Addendum I, October 2009. Group IV base stocks, i.e., polyalphaolefins (PAOs), are typically made by oligomerizing low molecular weight alpha olefins, such as alpha olefins containing at least 6 carbon atoms. In one embodiment, the alpha olefin is an alpha olefin containing 10 carbon atoms. PAOs are a mixture of dimers, trimers, tetramers, etc., and are accurately blended according to the desired final base stock viscosity. PAOs are typically hydrogenated after oligomerization to remove remaining unsaturates.

[0068] Group V base oils include all other base oils not included in Group I, Group II, Group III, or Group IV.

[0069] As described above, a cylinder lubricant for marine diesel engines typically has a kinematic viscosity in the range of 9.3 to 26.1 cSt at 100°C. To formulate such a lubricant, bright stock can be combined with a low-viscosity oil, such as an oil having a viscosity of 4 to 6 cSt at 100°C. However, since the supply of bright stock is gradually decreasing, reliance on bright stock cannot be used to increase the viscosity of the cylinder lubricant for marine engines to the desired range recommended by the manufacturer. One solution to this problem is to use a thickening agent such as polyisobutylene (PIB) or a viscosity index improver compound such as an olefin copolymer to increase the viscosity of the cylinder lubricant for marine engines. PIB is a commercially available material from several manufacturers. PIB is typically a viscous oil-miscible liquid having a weight average molecular weight in the range of about 1,000 to about 8,000, or about 1,500 to about 6,000, and a viscosity in the range of about 2,000 to about 5,000 or about 6,000 cS (100°C). The amount of PIB added to the cylinder lubricant for marine engines will usually be from about 1 to about 20 weight percent, or from about 2 to about 15 weight percent, or from about 4 to about 12 weight percent of the final oil.

[0070] In one embodiment, the marine diesel cylinder lubricant composition of the present invention further comprises one or more non-phosphated polyalkenyl bis(succinimide) dispersants, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000. Generally, bis(succinimide) is the completed reaction product from the reaction between a polyalkenyl-substituted succinic acid or anhydride and one or more polyamine reactants, and the product is intended to include compounds that may have amide, amidine, and / or salt linkages in addition to the type of imide bond obtained from the reaction between a primary amino group and an anhydride moiety. Bis(succinimide) dispersants are prepared according to methods well known in the art. For example, certain basic types of succinimide and related substances included in the term "succinimide" in the art are taught, for example, in U.S. Patent Nos. 2,992,708; 3,018,291; 3,024,237; 3,100,673; 3,219,666; 3,172,892; and 3,272,746, the contents of which are incorporated herein by reference.

[0071] In one embodiment, one or more non-phosphated polyalkenyl bis(succinimide) dispersants can be obtained by reacting a polyalkenyl-substituted succinic anhydride of formula I with a polyamine.

Chemical formula

[0072] The polyalkenyl succinic anhydride of formula I is commercially available from sources such as Sigma Aldrich Corporation (St. Louis, Missouri, USA), or can be prepared by any method well known in the art. For example, the preparation of polyalkenyl-substituted succinic anhydrides by the reaction of polyolefins with maleic anhydride is described, for example, in U.S. Pat. Nos. 3,018,250 and 3,024,195. Such methods include the thermal reaction of polyolefins with maleic anhydride, and the reaction of halogenated polyolefins, such as chlorinated polyolefins, with maleic anhydride. Reduction of the polyalkenyl-substituted succinic anhydride gives the corresponding alkyl derivative. Alternatively, the polyalkenyl-substituted succinic anhydride can be prepared as described, for example, in U.S. Pat. Nos. 4,388,471 and 4,450,281, the contents of which are incorporated herein by reference.

[0073] The size of the polyalkenyl substituent is advantageously derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000. In one embodiment, the size of the polyalkenyl substituent is advantageously derived from a polyalkene group having a number average molecular weight of from about 1500 to about 2500. In another embodiment, the size of the polyalkenyl substituent is advantageously derived from a polyalkene group having a number average molecular weight of about 2300.

[0074] The polyalkene group having a number average molecular weight of from about 1500 to about 3000 for the reaction with maleic anhydride or succinic anhydride, etc., is a polymer containing a major amount of C 2 to C 5 monoolefins, such as ethylene, propylene, butylene, isobutylene and pentene. The polymer can be a homopolymer such as polyisobutylene, and a copolymer of two or more such olefins such as a copolymer of ethylene with propylene, butylene and isobutylene, etc. Other copolymers can contain a small amount (e.g., 1 to 20 mole percent) of copolymer monomer, C 4 to C 8Non-conjugated diolefins, such as copolymers of isobutylene and butadiene or copolymers of ethylene, propylene and 1,4-hexadiene, etc., are included.

[0075] Particularly preferred classes of polyalkene groups having a number average molecular weight of from about 1500 to about 3000 include polybutenes prepared by the polymerization of one or more of 1-butene, 2-butene and isobutene. Polybutenes containing a substantial proportion of units derived from isobutene are particularly desirable. Polybutenes can contain small amounts of butadiene, which may or may not be incorporated into the polymer. In most cases, the isobutene units constitute about 80%, or at least about 90%, of the units in the polymer. These polybutenes are readily available commercially available materials well known to those skilled in the art, for example, those described in U.S. Patent Nos. 3,215,707; 3,231,587; 3,515,669; 3,579,450, and 3,912,764, the contents of which are incorporated herein by reference.

[0076] Polyamines suitable for use in the preparation of non-phosphated bis-succinimide dispersants include polyalkylene polyamines. Such polyalkylene polyamines typically contain from about 2 to about 12 nitrogen atoms and from about 2 to 24 carbon atoms. Particularly suitable polyalkylene polyamines are of the formula: H 2 N-(R 1 NH) c H (wherein R 1 is a straight or branched chain alkylene group having 2 or 3 carbon atoms and c is from 1 to 9). Representative examples of suitable polyalkylene polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and mixtures thereof. Most preferably, the polyalkylene polyamine is tetraethylenepentamine.

[0077] Many of the polyamines suitable for use in the present invention are commercially available, and others can be prepared by methods well known in the art. For example, methods for preparing amines and their reactions are described in detail in Sidgewick's "The Organic Chemistry of Nitrogen", Clarendon Press, Oxford, 1966; Noller's "Chemistry of Organic Compounds", Saunders, Philadelphia, 2nd Edition, 1957; and Kirk-Othmer's "Encyclopedia of Chemical Technology", 2nd Edition, particularly Volume 2, page 99, line 16.

[0078] Examples of suitable polyamines include tetraethylenepentamine, pentaethylenehexamine, and heavy polyamine (e.g., Dow HPA-X having a number average molecular weight of 275 available from The Dow Chemical Company, Midland, Michigan). Such amines include isomers such as the above-mentioned substituted polyamines, including branched-chain polyamines and hydrocarbyl-substituted polyamines. The HPA-X heavy polyamine ("HPA-X") contains an average of about 6.5 amine nitrogen atoms per molecule. Such heavy polyamines generally give excellent results.

[0079] Generally, the polyalkenyl-substituted succinic anhydride of Formula I reacts with the polyamine at a temperature of from about 130°C to about 220°C, preferably from about 145°C to about 175°C. This reaction can be carried out under an inert atmosphere such as nitrogen or argon. The amount of the anhydride of Formula I utilized in this reaction can range from about 30 to about 95% by weight, preferably from about 40 to about 60% by weight, based on the total weight of the reaction mixture.

[0080] Generally, in the marine diesel cylinder lubricant composition of the present invention, the concentration of one or more non-boronated polyalkenyl bis(succinimide) dispersants, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, is, on an active substance basis, more than about 0.25% by weight, or more than about 0.5% by weight, or more than about 1.0% by weight, or more than about 1.2% by weight, or more than about 1.5% by weight, or more than about 1.8% by weight, or more than about 2.0% by weight, or more than about 2.5% by weight, or more than about 2.8% by weight, based on the total weight of the marine diesel cylinder lubricant composition. In another embodiment, the amount of one or more non-boronated polyalkenyl bis(succinimide) dispersants in the marine diesel cylinder lubricant composition of the present invention, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, is, on an active substance basis, from about 0.25 to 10% by weight, or from about 0.25 to 8.0% by weight, or from about 0.25 to 5.0% by weight, or from about 0.25 to 4.0% by weight, or from 0.25 to 3.0% by weight, or from about 0.5 to 10% by weight, or from about 0.5 to 8.0% by weight, or from about 0.5 to 5.0% by weight, or from about 0.5 to 4.0% by weight, or from about 0.5 to 3.0% by weight, or from about 0.5 to 10% by weight, or from about 0.5 to 8.0% by weight, or from about 1.0 to 5.0% by weight, or from about 1.0 to 4.0% by weight, or from about 1.0 to 3.0% by weight, or from about 1.5 to 10% by weight, or from about 1.5 to 8.0% by weight, or from about 1.5 to 5.0% by weight, or from about 1.5 to 4.0% by weight, or from about 1.5 to 3.0% by weight, or from about 2.0 to 10% by weight, or from about 2.0 to 8.0% by weight, or from about 2.0 to 5.0% by weight, or from about 2.0 to 4.0% by weight, based on the total weight of the marine diesel cylinder lubricant composition.

[0081] In another embodiment, the marine diesel cylinder lubricant composition of the present invention further comprises a cyclic carbonate post-treated polyalkenyl bis(succinimide) dispersant. The polyalkenyl bis(succinimide) dispersant of this embodiment can be prepared by reacting a polyalkenyl-substituted succinic anhydride with a polyamine, as described above.

[0082] In this embodiment, the polyalkenyl-substituted succinic anhydride can be the polyalkenyl-substituted succinic anhydride when the polyalkenyl substituent is derived from a polyalkene having a number average molecular weight of about 500 to about 5000. In another embodiment, the polyalkenyl-substituted succinic anhydride according to this embodiment can be the polyalkenyl-substituted succinic anhydride when the polyalkenyl substituent is derived from a polyalkene having a number average molecular weight of about 700 to about 3000. In another embodiment, the polyalkenyl-substituted succinic anhydride according to this embodiment can be the polyalkenyl-substituted succinic anhydride when the polyalkenyl substituent is derived from a polyalkene having a number average molecular weight of about 1000 to about 3000. In another embodiment, the polyalkenyl-substituted succinic anhydride according to this embodiment can be the polyalkenyl-substituted succinic anhydride when the polyalkenyl substituent is derived from a polyalkene having a number average molecular weight of about 1300 to about 2500. In another embodiment, the polyalkenyl-substituted succinic anhydride according to this embodiment can be the polyalkenyl-substituted succinic anhydride when the polyalkenyl substituent is derived from a polyalkene having a number average molecular weight of about 1000 to about 2500. In another embodiment, the polyalkenyl-substituted succinic anhydride according to this embodiment can be the polyalkenyl-substituted succinic anhydride when the polyalkenyl substituent is derived from a polyalkene having a number average molecular weight of about 1500 to about 2500. In another embodiment, the polyalkenyl-substituted succinic anhydride according to this embodiment can be the polyalkenyl-substituted succinic anhydride when the polyalkenyl substituent is derived from a polyalkene having a number average molecular weight of about 2000 to about 2500.

[0083] The polyalkene group for forming the polyalkenyl-substituted succinic anhydride of this embodiment can be any of the above. Particularly preferred classes of polyalkene groups include polybutene, which is prepared by polymerization of one or more of 1-butene, 2-butene, and isobutene. Polybutene containing a substantial proportion of units derived from isobutene is particularly desirable.

[0084] The polyalkenyl bis-succinimide dispersant of this embodiment is post-treated with a cyclic carbonate to form a cyclic carbonate post-treated polyalkenyl bis-succinimide dispersant. Suitable cyclic carbonates for use in the present invention include, but are not limited to, 1,3-dioxolan-2-one (ethylene carbonate); 4-methyl-1,3-dioxolan-2-one (propylene carbonate); 4-hydroxymethyl-1,3-dioxolan-2-one; 4,5-dimethyl-1,3-dioxolan-2-one; 4-ethyl-1,3-dioxolan-2-one (butylene carbonate); 4,4-dimethyl-1,3-dioxolan-2-one; 4-methyl-5-ethyl-1,3-dioxolan-2-one; 4,5-diethyl-1,3-dioxolan-2-one; 4,4-diethyl-1,3-dioxolan-2-one; 1,3-dioxan-2-one; 4,4-dimethyl-1,3-dioxan-2-one; 5,5-dimethyl-1,3-dioxan-2-one; 5,5-dihydroxymethyl-1,3-dioxan-2-one; 5-methyl-1,3-dioxan-2-one; 4-methyl-1,3-dioxan-2-one, 5-hydroxy-1,3-dioxan-2-one; 5-hydroxymethyl-5-methyl-1,3-dioxan-2-one; 5,5-diethyl-1,3-dioxan-2-one; 5-methyl-5-propyl-1,3-dioxan-2-one; 4,6-dimethyl-1,3-dioxan-2-one; 4,4,6-trimethyl-1,3-dioxan-2-one, spiro[1,3-oxa-2-cyclohexanone-5,5'-1',3'-oxa-2'-cyclohexanone], and the like. Other suitable cyclic carbonates include sacchrides such as sorbitol, glucose, fructose, galactose, and C by methods known in the art.1 from C 30 It can be prepared from vicinal diols prepared from olefins.

[0085] Some of these cyclic carbonates are commercially available, such as 1,3-dioxolan-2-one or 4-methyl-1,3-dioxolan-2-one. Alternatively, the cyclic carbonate can be easily prepared by known reactions. For example, the cyclic carbonate for use in the present invention can be obtained by reacting phosgene with a suitable alpha-alkanediol or alkan-1,3-diol. See, for example, U.S. Patent No. 4,115,206, the content of which is incorporated herein by reference. Similarly, the cyclic carbonate useful in the present invention can be prepared by transesterification of a suitable alpha-alkanediol or alkan-1,3-diol with, for example, diethyl carbonate under transesterification conditions. See, for example, U.S. Patents Nos. 4,384,115 and 4,423,205, the content of which is incorporated herein by reference.

[0086] The polyalkenyl bisimide dispersant can be post-treated using a cyclic carbonate according to methods well known in the art. For example, the cyclic carbonate post-treated polyalkenyl bisimide dispersant can be prepared by a method comprising charging the bisimide dispersant into a reactor, optionally under a nitrogen purge, and heating at a temperature from about 80°C to about 170°C. Optionally, a diluent oil can be charged into the same reactor under a nitrogen purge. The cyclic carbonate is charged into the reactor, optionally under a nitrogen purge. This mixture is heated to a temperature in the range from about 130°C to about 200°C under a nitrogen purge. Optionally, the reaction mixture is brought to a reduced pressure for about 0.5 to about 2.0 hours to remove the water formed in the reaction.

[0087] Generally, the amount of one or more cyclic carbonate post-treated polyalkenyl bis-succinimide dispersants present in the marine diesel cylinder lubricant composition of the present invention is more than about 0.25 wt%, or more than about 0.5 wt%, or more than about 1.0 wt%, or more than about 1.2 wt%, or more than about 1.5 wt%, or more than about 1.8 wt%, or more than about 2.0 wt%, or more than about 2.5 wt%, or more than about 2.8 wt% on an active matter basis based on the total weight of the marine diesel cylinder lubricant composition. In another embodiment, the amount of one or more cyclic carbonate post-treated polyalkenyl bis-succinimide dispersants present in the marine diesel cylinder lubricant composition of the present invention is from about 0.25 to 10 wt%, or from about 0.25 to 8.0 wt%, or from about 0.25 to 5.0 wt%, or from about 0.25 to 4.0 wt%, or from 0.25 to 3.0 wt%, or from about 0.5 to 10 wt%, or from about 0.5 to 8.0 wt%, or from about 0.5 to 5.0 wt%, or from about 0.5 to 4.0 wt%, or from about 0.5 to 3.0 wt%, or from about 0.5 to 10 wt%, or from about 0.5 to 8.0 wt%, or from about 1.0 to 5.0 wt%, or from about 1.0 to 4.0 wt%, or from about 1.0 to 3.0 wt%, or from about 1.5 to 10 wt%, or from about 1.5 to 8.0 wt%, or from about 1.5 to 5.0 wt%, or from about 1.5 to 4.0 wt%, or from about 1.5 to 3.0 wt%, or from about 2.0 to 10 wt%, or from about 2.0 to 8.0 wt%, or from about 2.0 to 5.0 wt% or from about 2.0 to 4.0 wt% on an active matter basis based on the total weight of the marine diesel cylinder lubricant composition.

[0088] In order to impart auxiliary functions, the diesel cylinder lubricant composition for ships of the present invention also contains additives of conventional diesel cylinder lubricant compositions for ships other than the above dispersant, and a diesel cylinder lubricant composition in which these additives are dispersed or dissolved can be obtained. For example, the diesel cylinder lubricant composition for ships can be blended with antioxidants, detergents, antiwear agents, rust preventives, cloud point depressants, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoaming agents, cosolvents, corrosion inhibitors, dyes, extreme pressure agents, etc. and mixtures thereof. A variety of additives are known and commercially available. These additives or similar compounds thereof can be used in the preparation of the diesel cylinder lubricant composition for ships of the present invention by ordinary blending procedures.

[0089] In one embodiment, the diesel cylinder lubricant composition for ships of the present invention essentially does not contain a thickener (i.e., viscosity index improver).

[0090] One or more antioxidants capable of reducing or preventing oxidation of the base oil can be included in the diesel cylinder lubricating oil composition for ships of the present invention. Any antioxidant known to those skilled in the art can be used in the lubricating oil composition. Non-limiting examples of suitable antioxidants include amine-based antioxidants (e.g., alkyldiphenylamines such as bisnonylated diphenylamine, bisoctylated diphenylamine, and octylated / butylated diphenylamine, phenyl-α-naphthylamine, alkyl- or arylalkyl-substituted phenyl-α-naphthylamine, alkylated p-phenylenediamine, tetramethyldiaminodiphenylamine, etc.), phenolic antioxidants (e.g., 2-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-thiobis(6-di-tert-butyl-o-cresol), etc.), sulfur-based antioxidants (e.g., dilauryl-3,3'-thiodipropionate, sulfurized phenolic antioxidants, etc.), phosphorus-based antioxidants (e.g., phosphites, etc.), zinc dithiophosphate, oil-soluble copper compounds, and combinations thereof.

[0091] The amount of the antioxidant is from about 0.01% by weight to about 10% by weight, from about 0.05% by weight to about 5% by weight, or from about 0.1% by weight to about 3% by weight based on the total weight of the diesel cylinder lubricating oil composition for ships.

[0092] One or more detergents can be included in the diesel cylinder lubricant composition for ships of the present invention. Metal-containing detergents or ash-forming detergents function both as detergents for reducing or removing deposits and as acid neutralizers or rust inhibitors, thereby reducing wear and corrosion and extending engine life. Detergents generally consist of a polar head having a long hydrophobic tail. The polar head is composed of a metal salt of an acidic organic compound. The salts can contain substantially stoichiometric amounts of metal, in which case they are usually described as normal or neutral salts. A major amount of the metal base can be incorporated by reacting an excess of a metal compound (e.g., an oxide or hydroxide) with an acidic gas (e.g., carbon dioxide).

[0093] Useful detergents include, in particular, oil-soluble neutral and overbased sulfonates, phenates, sulfurized phenates, thiophosphonates, salicylates and naphthenates and other oil-soluble carboxylates of alkali or alkaline earth metals such as barium, sodium, potassium, lithium, calcium, and magnesium. The most commonly used metals are calcium and magnesium, which can both be present in the detergents used in lubricants and can be present in mixtures of calcium and / or magnesium with sodium.

[0094] Commercially available products are generally referred to as neutral or overbased. Overbased metal detergents are generally produced by carbonating a hydrocarbon, a detergent acid such as sulfonic acid, carboxylate, etc., a metal oxide or hydroxide (e.g., calcium oxide or calcium hydroxide) and an accelerator such as a mixture of xylene, methanol and water. For example, in carbonation, to prepare overbased calcium sulfonate, calcium oxide or calcium hydroxide is reacted with gaseous carbon dioxide to form calcium carbonate. The sulfonic acid is neutralized with an excess of CaO or Ca(OH) 2 to form a sulfonate.

[0095] The overbased detergent can be an overbased salt having a low overbase number, for example, an overbase number of less than 100. In one embodiment, the overbase number of the low overbase salt can be from about 5 to about 50. In another embodiment, the overbase number of the low overbase salt can be from about 10 to about 30. In yet another embodiment, the overbase number of the low overbase salt can be from about 15 to about 20.

[0096] The overbased detergent can be a mid-overbased salt having a mid-overbase number, for example, an overbase number from about 100 to about 250. In one embodiment, the overbase number of the mid-overbased salt can be from about 100 to about 200. In another embodiment, the overbase number of the mid-overbased salt can be from about 125 to about 175.

[0097] The overbased detergent can be a highly overbased salt having a high overbase number, for example, an overbase number greater than 250. In one embodiment, the overbase number of the highly overbased salt can be from about 250 to about 550.

[0098] In one embodiment, the detergent can be one or more alkali metal salts or alkaline earth metal salts of alkyl-substituted hydroxyaromatic carboxylic acids. Suitable hydroxyaromatic compounds include mononuclear mono-hydroxy and poly-hydroxy aromatic hydrocarbons having from 1 to 4, preferably from 1 to 3, hydroxyl groups. Suitable hydroxyaromatic compounds include phenol, catechol, resorcinol, hydroquinone, pyrogallol, cresol, and the like. A preferred hydroxyaromatic compound is phenol.

[0099] The alkyl-substituted moiety of the alkali metal salt or alkaline earth metal salt of the alkyl-substituted hydroxyaromatic carboxylic acid is derived from an alpha olefin having from about 10 to about 80 carbon atoms. The olefin used can be linear, isomerized linear, branched, or partially branched linear. The olefin can be a mixture of linear olefins, a mixture of isomerized linear olefins, a mixture of branched olefins, a mixture of partially branched linear olefins, or any mixture thereof.

[0100] In one embodiment, the mixture of linear olefins that can be used is a mixture of normal alpha olefins selected from olefins having from about 12 to about 30 carbon atoms per molecule. In one embodiment, the normal alpha olefins are isomerized using at least one of a solid catalyst or a liquid catalyst.

[0101] In another embodiment, the olefin is a branched olefinic propylene oligomer having from about 20 to about 80 carbon atoms or a mixture thereof, i.e., a branched olefin derived from the polymerization of propylene. The olefin may be substituted with other functional groups such as hydroxy groups, carboxylic acid groups, heteroatoms, etc. In one embodiment, the branched olefinic propylene oligomer or a mixture thereof has from about 20 to about 60 carbon atoms. In one embodiment, the branched olefinic propylene oligomer or a mixture thereof has from about 20 to about 40 carbon atoms.

[0102] In one embodiment, at least about 75 mol% (e.g., at least about 80 mol%, at least about 85 mol%, at least about 90 mol%, at least about 95 mol%, or at least about 99 mol%) of the alkyl groups contained in the alkali metal salts or alkaline earth metal salts of alkyl-substituted hydroxybenzoic acid detergents, such as the alkyl groups of the alkaline earth metal salts of alkyl-substituted hydroxybenzoic acid, are C 20 or more. In another embodiment, the alkali metal salt or alkaline earth metal salt of the alkyl-substituted hydroxyaromatic carboxylic acid is an alkali metal salt or alkaline earth metal salt of an alkyl-substituted hydroxybenzoic acid derived from an alkyl-substituted hydroxybenzoic acid residue of normal alpha-olefins containing at least 75 mol% of C 20 or more of normal alpha-olefins.

[0103] In another embodiment, at least about 50 mol% (e.g., at least about 60 mol%, at least about 70 mol%, at least about 80 mol%, at least about 85 mol%, at least about 90 mol%, at least about 95 mol%, or at least about 99 mol%) of the alkyl groups, such as the alkyl groups of the alkali metal salts or alkaline earth metal salts of alkyl-substituted hydroxybenzoic acids, contained in the alkali metal salts or alkaline earth metal salts of alkyl-substituted hydroxyaromatic carboxylic acids are from about C 14 to about C 18 is.

[0104] The resulting alkali metal salts or alkaline earth metal salts of alkyl-substituted hydroxyaromatic carboxylic acids will be a mixture of ortho and para isomers. In one embodiment, the product will contain from about 1 to 99% ortho isomer and 99 to 1% para isomer. In another embodiment, the product will contain from about 5 to 70% ortho isomer and 95 to 30% para isomer.

[0105] The alkali metal salts or alkaline earth metal salts of alkyl-substituted hydroxyaromatic carboxylic acids can be neutral or overbased. Generally, the overbased alkali metal salts or alkaline earth metal salts of alkyl-substituted hydroxyaromatic carboxylic acids are those in which the BN of the alkali metal salts or alkaline earth metal salts of alkyl-substituted hydroxyaromatic carboxylic acids has been increased by a process such as the addition of a base source (e.g., lime) and an acidic overbasing compound (e.g., carbon dioxide).

[0106] Sulfonates can typically be prepared from sulfonic acids obtained by sulfonation of alkyl-substituted aromatic hydrocarbons, for example, those obtained from fractions of petroleum or by alkylation of aromatic hydrocarbons. Examples include those obtained by alkylating benzene, toluene, xylene, naphthalene, diphenyl or their halogen derivatives. Alkylation can be carried out in the presence of a catalyst using an alkylating agent having from about 3 to more than 70 carbon atoms. Alkaryl sulfonates usually contain from about 9 to about 80 or more carbon atoms, preferably from about 16 to about 60 carbon atoms per alkyl-substituted aromatic moiety.

[0107] Oil-soluble sulfonates or alkaryl sulfonic acids can be neutralized using metal oxides, hydroxides, alkoxides, carbonates, carboxylates, sulfides, hydrosulfides, nitrates, borates and ethers. The amount of the metal compound is selected considering the desired TBN of the final product, but is typically in the range of about 100 to about 220% by weight (preferably at least about 125% by weight) of the stoichiometrically required amount.

[0108] Metal salts of phenol and sulfurized phenol are prepared by reaction with a suitable metal compound, such as an oxide or hydroxide, and neutral or overbased products can be obtained by methods well known in the art. Sulfurized phenol is prepared by reacting phenol with sulfur or a sulfur-containing compound, such as hydrogen sulfide, sulfur monohalide or sulfur dihalide, to form a product which is generally a mixture of compounds in which two or more phenols are bridged by sulfur-containing bridges.

[0109] Generally, the amount of the detergent can be from about 0.001% to about 25% by weight, or from about 0.05% to about 20% by weight, or from about 0.1% to about 15% by weight based on the total weight of the marine diesel cylinder lubricant composition.

[0110] The marine diesel cylinder lubricant composition of the present invention can contain one or more friction modifiers capable of reducing friction between moving parts. Any friction modifier known to those skilled in the art can be used in the marine diesel cylinder lubricant composition. Non-limiting examples of suitable friction modifiers include aliphatic carboxylic acids; derivatives of aliphatic carboxylic acids (e.g., alcohols, esters, borate esters, amides, metal salts, etc.); mono-, di- or tri-alkyl-substituted phosphoric acids or phosphonic acids; derivatives of mono-, di- or tri-alkyl-substituted phosphoric acids or phosphonic acids (e.g., esters, amides, metal salts, etc.); mono-, di- or tri-alkyl-substituted amines; mono- or di-alkyl-substituted amides and combinations thereof. In some embodiments, examples of friction modifiers include, but are not limited to, alkoxylated aliphatic amines; boricated aliphatic epoxides; aliphatic phosphites, aliphatic epoxides, aliphatic amines, boricated alkoxylated aliphatic amines, metal salts of fatty acids, fatty acid amides, glycerol esters, boricated glycerol esters; and aliphatic imidazolines (these are disclosed in U.S. Patent No. 6,372,696, the content of which is incorporated herein by reference); friction modifiers obtained from reaction products of fatty acid esters of C 4 to C 75 or C 6 to C 24 or C 6 to C 20 and nitrogen-containing compounds selected from the group consisting of ammonia, alkanolamines, etc. and mixtures thereof are included.

[0111] The amount of the friction modifier can be varied from about 0.01 wt% to about 10 wt%, from about 0.05 wt% to about 5 wt%, or from about 0.1 wt% to about 3 wt% based on the total weight of the marine diesel cylinder lubricant composition.

[0112] The diesel cylinder lubricating oil composition for ships of the present invention can contain one or more anti-wear agents capable of reducing friction and excessive wear. Anti-wear agents known to those skilled in the art can be used in the lubricating oil composition. Non-limiting examples of suitable anti-wear agents include zinc dithiophosphate, metal (e.g., Pb, Sb, Mo, etc.) salts of dithiophosphoric acid, metal (e.g., Zn, Pb, Sb, Mo, etc.) salts of dithiocarbamic acid, metal (e.g., Zn, Pb, Sb, etc.) salts of fatty acids, boron compounds, phosphate esters, phosphite esters, amine salts of phosphate esters or thiophosphate esters, reaction products of dicyclopentadiene and thiophosphoric acid, and combinations thereof.

[0113] The amount of the anti-wear agent can be varied from about 0.01% by weight to about 5% by weight, or from about 0.05% by weight to about 3% by weight, or from about 0.1% by weight to about 1% by weight based on the total weight of the diesel cylinder lubricating oil composition for ships.

[0114] In certain embodiments, the anti-wear agent is a metal salt of dihydrocarbyl dithiophosphate, such as a zinc dialkyldithiophosphate compound, or includes this. The metal of the metal salt of dihydrocarbyl dithiophosphate can be an alkali metal or alkaline earth metal, or aluminum, lead, tin, molybdenum, manganese, nickel or copper. In some embodiments, the metal is zinc. In other embodiments, the alkyl group of the metal salt of dihydrocarbyl dithiophosphate has about 3 to about 22 carbon atoms, about 3 to about 18 carbon atoms, about 3 to about 12 carbon atoms, or about 3 to about 8 carbon atoms. In further embodiments, the alkyl group is linear or branched.

[0115] The amount of the metal salt of dihydrocarbyl dithiophosphate containing zinc dialkyldithiophosphate in the lubricating oil composition disclosed herein is measured by the phosphorus content. In some embodiments, the phosphorus content of the lubricating oil composition disclosed herein is from about 0.01% by weight to about 0.14% by weight based on the total weight of the lubricating oil composition.

[0116] In the diesel cylinder lubricating oil composition for ships of the present invention, one or more foam inhibitors or anti-foam inhibitors capable of breaking the foam in the oil can be contained. Foam inhibitors or anti-foam inhibitors known to those skilled in the art can be used in the diesel cylinder lubricating oil composition for ships. Non-limiting examples of suitable foam inhibitors or anti-foam inhibitors include silicone oil or polydimethylsiloxane, fluorosilicone, alkoxylated fatty acids, polyethers (e.g., polyethylene glycol), branched polyvinyl ethers, alkyl acrylate polymers, alkyl methacrylate polymers, polyalkoxyamines, and combinations thereof. In some embodiments, the foam inhibitor or anti-foam inhibitor includes glycerol monostearate, polyglycol palmitate, trialkyl monothiophosphate, ester of sulfonated ricinoleic acid, benzoylacetone, methyl salicylate, glycerol monooleate, or glycerol dioleate.

[0117] The amount of the foam inhibitor or anti-foam inhibitor can be varied from about 0.001% by weight to about 5% by weight, or from about 0.05% by weight to about 3% by weight, or from about 0.1% by weight to about 1% by weight based on the total weight of the diesel cylinder lubricating oil composition for ships.

[0118] In the diesel cylinder lubricating oil composition for ships of the present invention, one or more pour point depressants capable of lowering the pour point of the diesel cylinder lubricating oil composition for ships can be contained. Any pour point depressant known to those skilled in the art can be used in the diesel cylinder lubricating oil composition for ships. Non-limiting examples of suitable pour point depressants include polymethacrylate, alkyl acrylate polymers, alkyl methacrylate polymers, di(tetra-paraffin phenol) phthalate, condensate of tetraparaffin phenol, condensate of chlorinated paraffin and naphthalene, and combinations thereof. In some embodiments, the pour point depressant includes ethylene-vinyl acetate copolymer, condensate of chlorinated paraffin and phenol, polyalkylstyrene, etc.

[0119] The amount of the pour point depressant can be varied from about 0.01% by weight to about 10% by weight, or from about 0.05% by weight to about 5% by weight, or from about 0.1% by weight to about 3% by weight based on the total weight of the marine diesel cylinder lubricating oil composition.

[0120] In one embodiment, the marine diesel cylinder lubricating oil composition of the present invention does not contain one or more demulsifiers. In another embodiment, the marine diesel cylinder lubricating oil composition of the present invention can contain one or more demulsifiers that can promote oil-water separation in the lubricating oil composition exposed to water or steam. Any demulsifier known to those skilled in the art can be used in the marine diesel cylinder lubricating oil composition. Non-limiting examples of suitable demulsifiers include anionic surfactants (e.g., alkylnaphthalene sulfonate, alkylbenzene sulfonate, etc.), nonionic alkoxylated alkylphenol resins, polymers of alkylene oxides (e.g., block copolymers of polyethylene oxide, polypropylene oxide, ethylene oxide, propylene oxide, etc.), esters of oil-soluble acids, polyoxyethylene sorbitan esters, and combinations thereof.

[0121] The amount of the demulsifier can be varied from about 0.01% by weight to about 10% by weight, or from about 0.05% by weight to about 5% by weight, or from about 0.1% by weight to about 3% by weight based on the total weight of the marine diesel cylinder lubricating oil composition.

[0122] The marine diesel cylinder lubricating oil composition of the present invention can contain one or more corrosion inhibitors that can reduce corrosion. Any corrosion inhibitor known to those skilled in the art can be used in the marine diesel cylinder lubricating oil composition. Non-limiting examples of suitable corrosion inhibitors include half esters or amides of dodecyl succinic acid, phosphate esters, thiophosphates, alkyl imidazolines, sarcosine, and combinations thereof.

[0123] The amount of the corrosion inhibitor can be varied from about 0.01% by weight to about 5% by weight, or from about 0.05% by weight to about 3% by weight, or from about 0.1% by weight to about 1% by weight, based on the total weight of the marine diesel cylinder lubricating oil composition.

[0124] The marine diesel cylinder lubricating oil composition of the present invention can contain one or more extreme pressure (EP) agents capable of preventing the sliding metal surface from seizing under extreme pressure conditions. Any extreme pressure agent known to those skilled in the art can be used in the marine diesel cylinder lubricating oil composition. Generally, an extreme pressure agent is a compound that can chemically bond with a metal to form a surface film that prevents the unevenness of the opposing metal surfaces from welding under high loads. Non-limiting examples of suitable extreme pressure agents include sulfided animal or vegetable oils and fats, sulfided animal or vegetable fatty acid esters, esters completely or partially esterified with trivalent or pentavalent acids of phosphorus, sulfurized olefins, dihydrocarbyl polysulfides, sulfurized Diels - Alder adducts, sulfurized dicyclopentadiene, sulfurized or co-sulfurized mixtures of fatty acid esters and mono-unsaturated olefins, co-sulfurized blends of fatty acids, fatty acid esters and alpha-olefins, functional group-substituted dihydrocarbyl polysulfides, thia aldehydes, thia ketones, episulfide compounds, sulfur-containing acetal derivatives, co-sulfurized blends of terpenes and acyclic olefins, and polysulfide olefin products, amine salts of phosphate esters or thiophosphate esters, and combinations thereof.

[0125] The amount of the extreme pressure agent can be varied from about 0.01% by weight to about 5% by weight, or from about 0.05% by weight to about 3% by weight, or from about 0.1% by weight to about 1% by weight, based on the total weight of the marine diesel cylinder lubricating oil composition.

[0126] The diesel cylinder lubricating oil composition for ships of the present invention can contain one or more rust inhibitors capable of suppressing corrosion of the ferrous metal surface. Any rust inhibitor known to those skilled in the art can be used in the diesel cylinder lubricating oil composition for ships. Non-limiting examples of suitable rust inhibitors include nonionic polyoxyalkylene agents such as polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene octyl stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol monooleate, and polyethylene glycol monooleate; stearic acid and other fatty acids; dicarboxylic acids; metal soaps; fatty acid amine salts; metal salts of heavy sulfonic acids; partial carboxylic acid esters of polyhydric alcohols; phosphate esters; (short-chain) alkenyl succinic acids; their partial esters and their nitrogen-containing derivatives; synthetic alkylaryl sulfonates such as metal salts of dinonylnaphthalene sulfonic acid; and the like, as well as mixtures thereof.

[0127] The amount of the rust inhibitor can be varied from about 0.01 wt% to about 10 wt%, or from about 0.05 wt% to about 5 wt%, or from about 0.1 wt% to about 3 wt% based on the total weight of the diesel cylinder lubricating oil composition for ships.

[0128] The diesel cylinder lubricating oil composition for ships of the present invention can contain one or more multifunctional additives. Non-limiting examples of suitable multifunctional additives include sulfurized oxymolybdenum dithiocarbamate, sulfurized oxymolybdenum organophosphorodithioate, oxymolybdenum monoglyceride, oxymolybdenum diethylate amide, amine-molybdenum complex compounds, and sulfur-containing molybdenum complex compounds.

[0129] One or more viscosity index improvers can be included in the diesel cylinder lubricating oil composition for ships of the present invention. Non-limiting examples of suitable viscosity index improvers include, but are not limited to, olefin copolymers such as ethylene-propylene copolymers, styrene-isoprene copolymers, hydrated styrene-isoprene copolymers, polybutene, polyisobutylene, polymethacrylate, copolymers of vinyl pyrrolidone and methacrylate, and dispersant-type viscosity index improvers. These viscosity modifiers can optionally be grafted with a grafting material such as maleic anhydride, and the grafting material can react with, for example, amines, amides, nitrogen-containing heterocyclic compounds or alcohols to form multifunctional viscosity modifiers (dispersant-viscosity modifiers). Other examples of viscosity modifiers include star polymers (e.g., star polymers containing isoprene / styrene / isoprene triblocks). Still other examples of viscosity modifiers include polyalkyl (meth)acrylates with low Brookfield viscosity and high shear stability, functional polyalkyl (meth)acrylates with high Brookfield viscosity and high shear stability and dispersant properties, polyisobutylene having a weight average molecular weight of from 700 to 2,500 daltons, and mixtures thereof.

[0130] The amount of the viscosity index improver can be varied from about 0.01% by weight to about 25% by weight, or from about 0.05% by weight to about 20% by weight, or from about 0.3% by weight to about 15% by weight based on the total weight of the diesel cylinder lubricating oil composition for ships.

[0131] One or more metal deactivators can be included in the diesel cylinder lubricating oil composition for ships of the present invention. Non-limiting examples of suitable metal deactivators include disalicylidene propylenediamine, triazole derivatives, thiadiazole derivatives, and mercaptobenzimidazole.

[0132] In addition, the additives of the marine diesel cylinder lubricant composition can be provided as an additive package or concentrate, where the additives are mixed in a substantially inert, usually liquid, organic diluent as described above. The additive package will typically contain one or more of the various additives as described above in the desired amounts and ratios to facilitate direct mixing with the required amount of lubricating viscosity oil.

[0133] The present invention will be illustrated by the following non-limiting examples.

[0134] The advantages of the present invention were demonstrated by evaluating Group I and Group II base marine cylinder lubricant compositions containing various succinimide dispersants in a baseline formulation against a lubricant composition of the same baseline formulation but without dispersants.

[0135] The degree of stability against viscosity increase due to oxidation of the marine cylinder lubricant composition of the present invention was evaluated using the Modified Institute of Petroleum 48 (MIP-48) test.

[0136] Modified Institute of Petroleum 48 (MIP-48) test

[0137] The MIP-48 test consists of a heat part and an oxidation part. Between the two parts of the test, the test sample is heated for a certain time. In the heat part of the test, nitrogen is passed through the heated oil sample for 24 hours, and in parallel, air is passed through the heated oil sample for 24 hours during the oxidation part of the test. The two samples are cooled and the viscosities of the two samples are measured. The increase in viscosity of the test oil caused by oxidation is measured and corrected for the effect of heat. The viscosity increase due to oxidation for each marine cylinder lubricant composition is calculated by subtracting the kinematic viscosity at 200 °C of the nitrogen-sparged sample from the kinematic viscosity at 200 °C of the air-sparged sample and then dividing the result of that subtraction by the kinematic viscosity at 200 °C of the nitrogen-sparged sample. This is corrected for the effect of potential evaporation during the test or other heat effects, thereby focusing on the effect of oxidation. This correction can result in a negative value. Test oils that show better stability against viscosity increase due to oxidation will show lower % values.

[0138] In addition, the ability of the marine cylinder lubricant compositions of the present invention to suppress foaming was evaluated using the following foaming test.

[0139] Foaming Test

[0140] Summary of Test Method

[0141] This test method includes the measurement of the foaming characteristics of lubricating oils at 24 °C and 93.5 °C. Air is blown into a sample maintained at a temperature of 24 °C (75 °F) at a constant rate for 5 minutes and then left to stand for 10 minutes ("Sequence I"). The volume of the foam is measured at the end of both periods. The test is repeated for a second sample at 93.5 °C (200 °F) ("Sequence II") and then, after breaking the foam, at 24 °C (75 °F) ("Sequence III").

[0142] Importance and Use

[0143] The foaming tendency of oils can be a serious problem in systems such as high-speed gearing, high-volume pumping, and splash lubrication. Inadequate lubrication, cavitation, and overflow losses of the lubricant can lead to mechanical failure. This test method is used for the evaluation of oils for such operating conditions.

[0144] The following components are used as follows when formulating a marine diesel cylinder lubricant composition.

[0145] ExxonMobil CORE® 150N: A Group I base lubricating oil available from ExxonMobil (Irving, Texas).

[0146] ExxonMobil CORE® 600N: A Group I base lubricating oil available from ExxonMobil (Irving, Texas).

[0147] Esso Core® 2500BS: A Group I bright stock available from ExxonMobil (Irving, Texas).

[0148] Chevron 600N: A Group II base lubricating oil available from Chevron Corporation (San Ramon, California).

[0149] Chevron RLOP 100: A Group II base lubricating oil available from Chevron Corporation (San Ramon, California).

[0150] The succinimide dispersants used in the following examples are described below:

[0151] Dispersant A: An oil concentrate of a dispersant mainly composed of bis-succinimide derived from polyisobutylene having a number average molecular weight (Mn) of 1000 and heavy polyamine / diethylenetriamine (80 / 20 weight / weight). This additive contains 2.0% nitrogen, about 32% diluent oil, and has a TBN of 38 mg·KOH / g.

[0152] Dispersant B: An oil concentrate of a dispersant mainly composed of bis-succinimide derived from polyisobutylene having an Mn of 1300 and heavy polyamine / diethylenetriamine (80 / 20 weight / weight). This additive contains 1.45% nitrogen, about 39% diluent oil, and has a TBN of 27 mg·KOH / g.

[0153] Dispersant C: An oil concentrate of a dispersant mainly composed of bis-succinimide of post-treated with boric acid, derived from polyisobutylene having an Mn of 1300 and heavy polyamine. This additive contains 1.95% nitrogen, 0.63% boron, about 37% diluent oil, and has a TBN of 43 mg·KOH / g.

[0154] Dispersant D: An oil concentrate of a dispersant mainly composed of bis-succinimide of post-treated with ethylene carbonate, derived from polyisobutylene having an Mn of 2300 and heavy polyamine. This additive contains 1.0% nitrogen, about 43% diluent oil (about 57% active substance), and has a TBN of 12.5 mg·KOH / g. Dispersant E: An oil concentrate of a bis-succinimide dispersant derived from polyisobutylene having an Mn of 2300 and heavy polyamine. This additive contains 1.25% nitrogen, about 42% diluent oil, and has a TBN of 29 mgKOH / g. This dispersant is the succinimide precursor of Dispersant D before the post-treatment step with ethylene carbonate.

[0155] The amounts of dispersant concentrate shown in the following table are based on the amount of oil concentrate added to the formulation, not on the amount of active dispersant. The amounts of dispersants A, B, C, and E in the examples were determined on an equimolar basis by the moles of amine that make up the core of the bis-succinimide dispersant such that they are equal on a molar basis to 5.0 wt% (2.9 wt% active substance) of dispersant D. The dispersants were then added to the composition on an equimolar basis. Next, dispersant D was downtreated to additive concentrations of 2.5 wt% and 3.5 wt% (1.4 wt% active substance and 2.0 wt% active substance, respectively) in some examples in order to evaluate the critical concentration level. Examples 1 to 7 and Comparative Examples 1 to 5 As shown in Table 1 below, marine cylinder lubricant compositions of Examples 1 to 7 and Comparative Examples 1 to 5 were prepared. Each marine cylinder lubricant composition was formulated to an SAE 50 viscosity grade using a major amount of Group I base stock. The marine cylinder lubricant compositions of Examples 5 and 7 contained the following additives: namely, an oil concentrate of 114BN calcium alkylphenate detergent, an oil concentrate of 260BN calcium alkylphenate detergent, an oil concentrate of 410BN highly overbased alkyl aromatic calcium sulfonate detergent, zinc dialkyldithiophosphate, and an antifoaming agent. The marine cylinder lubricant compositions of the remaining examples in Table 1 contained the following additives: namely, an oil concentrate of 114BN calcium alkylphenate detergent, an oil concentrate of 150BN overbased detergent containing a calcium salt of linear alkyl-substituted hydroxybenzoic acid, an oil concentrate of 410BN highly overbased alkyl aromatic calcium sulfonate detergent, and an antifoaming agent. Comparative Example 1 contained no succinimide dispersant and was a reference oil. The amounts of dispersants in Comparative Examples 3, 4, and 5 and Examples 6 and 7 are equal to 5.0 wt% of dispersant D on an equimolar basis. Examples 6 and 7 contained higher molecular weight succinimide dispersants that were not post-treated with ethylene carbonate.

Table 1

[0156] As can be seen from the results shown in Table 1, the marine diesel cylinder lubricant compositions of Examples 1 to 7 showed surprisingly good or equivalent stability against viscosity increase due to oxidation, as evidenced by the % viscosity increase measured by the MIP-48 test being equal to or lower than that of the Group I-based cylinder lubricants of Comparative Examples 1 to 5. Also, the foaming tendency of the marine diesel cylinder lubricant compositions of Examples 1 to 7 was significantly improved compared to the comparative examples. In addition, the marine diesel cylinder lubricant compositions of Examples 1 to 7 achieved the desired viscosity using less bright stock (designated as Esso Core 2500BS in the example) than the marine diesel cylinder lubricant compositions of the comparative examples. Examples 8 to 12 and Comparative Examples 6 to 9

[0157] As shown in Table 2 below, marine cylinder lubricant compositions of Examples 8 to 12 and Comparative Examples 6 to 9 were prepared. Each marine cylinder lubricant composition was formulated to an SAE 50 viscosity grade using a major amount of Group II base stock. The marine cylinder lubricant composition of Example 12 further contained an oil concentrate of 114BN calcium alkylphenate detergent, an oil concentrate of 260BN calcium alkylphenate detergent, an oil concentrate of 410BN highly overbased alkyl aromatic calcium sulfonate detergent, zinc dialkyldithiophosphate of the second grade, and an antifoaming agent. The marine cylinder lubricant compositions of the remaining examples in Table 2 contained the following additives: namely, an oil concentrate of 114BN calcium alkylphenate detergent, an oil concentrate of 150BN overbased detergent containing calcium salt of linear alkyl-substituted hydroxybenzoic acid, an oil concentrate of 410BN highly overbased alkyl aromatic calcium sulfonate detergent, and an antifoaming agent. Comparative Example 6 contained no succinimide dispersant and was the reference oil. The amount of dispersant in Comparative Examples 7, 8, and 9 was equal to 5.0 wt% of dispersant D on an equimolar basis.

Table 2

[0158] As can be seen from the results shown in Table 2, the marine diesel cylinder lubricant compositions of Examples 9, 11, and 12 showed surprisingly good stability against viscosity increase due to oxidation, as evidenced by a lower % viscosity increase measured by the MIP-48 test compared to the Group II-based marine diesel cylinder lubricant compositions of Comparative Examples 6 to 9. Also, the foaming tendency of the marine diesel cylinder lubricant compositions of Examples 9, 11, and 12 was significantly better than that of the Comparative Examples. Examples 8 and 10 of the present invention provided improved viscosity increase performance and substantially equivalent foaming performance compared to the Comparative Examples using approximately half the molar equivalent of dispersant. In addition, the marine diesel cylinder lubricant compositions of Examples 8 to 12 achieved the desired viscosity using less bright stock than the marine diesel cylinder lubricant compositions of the Comparative Examples. Examples 13 and 14 and Comparative Examples 10 to 14

[0159] As shown in Table 3 below, marine cylinder lubricant compositions of Examples 13 and 14 and Comparative Examples 10 to 14 were prepared. Each marine cylinder lubricant composition was formulated into an SAE 50 viscosity grade oil using a major amount of Group I base stock. Each of the marine cylinder lubricant compositions further contained the following additives: namely, an oil concentrate of a 410 BN highly overbased alkyl aromatic calcium sulfonate detergent, an oil concentrate of a 19 BN non-overbased alkyl aromatic calcium sulfonate detergent, zinc dialkyldithiophosphate, an amine antioxidant, and an antifoaming agent. Comparative Example 10 is a reference oil and does not contain a succinimide dispersant. The amount of dispersant in Comparative Examples 12, 13, and 14 is equal to 5.0 wt% of the dispersant on an equimolar basis.

Table 3

[0160] As can be seen from the results shown in Table 3, the marine diesel cylinder lubricant compositions of Examples 13 and 14 showed equivalent or surprisingly good stability against viscosity increase due to oxidation, as evidenced by a lower % viscosity increase measured by the MIP-48 test. Also, the foaming tendency of the marine diesel cylinder lubricant compositions of Examples 13 and 14 was directionally good compared to the comparative examples. In particular, Example 13 provided improved foaming performance with a lower molar equivalent of dispersant than the comparative examples. Additionally, the marine diesel cylinder lubricant compositions of Examples 13 and 14 achieved the desired viscosity using less bright stock than the marine diesel cylinder lubricant compositions of the comparative examples, respectively. Examples 15 and 16 and Comparative Examples 15 to 19

[0161] As shown in Table 4 below, marine cylinder lubricant compositions of Examples 15 and 16 and Comparative Examples 15 to 19 were prepared. Each marine cylinder lubricant composition was formulated into an SAE 50 viscosity grade oil using a major amount of Group II base stock. Each of the marine cylinder lubricant compositions contained the following additives in similar amounts: namely, an oil concentrate of a 410 BN highly overbased alkyl aromatic calcium sulfonate detergent, an oil concentrate of a 19 BN non-overbased alkyl aromatic calcium sulfonate detergent, zinc dialkyldithiophosphate, an amine antioxidant, and an antifoaming agent. Comparative Example 15 is a reference oil and does not contain a succinimide dispersant. The amount of dispersant in Comparative Examples 17, 18, and 19 is equal to 5.0 wt% of dispersant D on an equimolar basis.

Table 4

[0162] As can be seen from the results shown in Table 4, the marine diesel cylinder lubricant compositions of Examples 15 and 16 showed equivalent or surprisingly good stability against viscosity increase due to oxidation, as evidenced by a lower % viscosity increase measured by the MIP-48 test compared to the marine diesel cylinder lubricant compositions of Group II-based cylinder lubricants of Comparative Examples 15 to 19. Also, the foaming tendency of the marine diesel cylinder lubricant compositions of Examples 15 and 16 was either significantly improved compared to each comparative example or comparable to the comparative examples. In particular, in Example 15, improved foaming characteristics were obtained with a molar equivalent amount of dispersant less than that of the comparative examples. In addition, the marine diesel cylinder lubricant compositions of Examples 15 and 16 achieved the desired viscosity using a lower amount of bright stock compared to the comparative examples. Examples 17 and Comparative Examples 20 to 23

[0163] As shown in Table 5 below, marine cylinder lubricant compositions of Example 17 and Comparative Examples 20 to 23 were prepared. Each marine cylinder lubricant composition was formulated into an SAE 50 viscosity grade oil using a major amount of Group II base stock. Each of the marine cylinder lubricant compositions further contained the following additives in similar amounts: namely, an oil concentrate of 114 BN calcium alkylphenate detergent, an oil concentrate of 410 BN highly overbased alkyl aromatic calcium sulfonate detergent, an oil concentrate of 19 BN non-overbased alkyl aromatic calcium sulfonate detergent, an amine antioxidant, and an antifoaming agent. Comparative Example 20 is a reference oil and does not contain a succinimide dispersant. The amounts of the dispersants in Comparative Examples 21, 22, and 23 are equal to 5.0 wt% of dispersant D on an equimolar basis.

Table 5

[0164] As can be seen from the results shown in Table 5, the marine diesel cylinder lubricant composition of Example 17 showed surprisingly good stability against viscosity increase due to oxidation, as evidenced by a lower % viscosity increase measured by the MIP-48 test compared to the marine diesel cylinder lubricant compositions of the Group II base cylinder lubricants of Comparative Examples 20 to 23. Also, the foaming tendency of the marine diesel cylinder lubricant composition of Example 17 was significantly better compared to each of the comparative examples. In addition, the marine diesel cylinder lubricant composition of Example 17 achieved the desired viscosity using less bright stock than the marine diesel cylinder lubricant compositions of the comparative examples. Examples 18 and 19 and Comparative Examples 24 to 27

[0165] As shown in Table 6 below, marine cylinder lubricant compositions of Examples 18 and 19 and Comparative Examples 24 to 27 were prepared. Each marine cylinder lubricant composition was formulated into an SAE 60 viscosity grade oil using a major amount of Group I base stock. Each of the marine cylinder lubricant compositions further contained the following additives in similar amounts: namely, an oil concentrate of 114 BN calcium alkylphenate detergent, an oil concentrate of 410 BN highly overbased alkyl aromatic calcium sulfonate detergent, an oil concentrate of 260 BN calcium alkylphenate detergent, secondary zinc dialkyldithiophosphate, and an antifoaming agent. Comparative Example 24 is a reference oil and does not contain a succinimide dispersant. The amount of dispersant in Comparative Examples 25, 26, and 27 is equal to 5.0 wt% of dispersant D on an equimolar basis.

Table 6

[0166] As can be seen from the results shown in Table 6, the marine diesel cylinder lubricant compositions of Examples 18 and 19 showed surprisingly good stability against viscosity increase due to oxidation, as evidenced by a lower % viscosity increase measured by the MIP-48 test compared to the marine diesel cylinder lubricant compositions of the Group I base cylinder lubricants of Comparative Examples 24 to 27. Also, the foaming tendency of the marine diesel cylinder lubricant compositions of Examples 18 and 19 was equal to or significantly better than that of each comparative example. In addition, the marine diesel cylinder lubricant compositions of Examples 18 and 19 achieved the desired viscosity using less bright stock than the marine diesel cylinder lubricant compositions of each comparative example.

[0167] It will be understood that various changes may be made to the embodiments disclosed herein. Accordingly, the above description should be construed as illustrative rather than limiting, merely as an example of a preferred embodiment. For example, the functions described and implemented above are for illustrative purposes only as the best mode for carrying out the present invention. Other configurations and methods can be implemented by those skilled in the art without departing from the scope and essence of the present invention. Further, those skilled in the art will envision other changes within the scope and essence of the appended claims herein.

[0168] The following is a list of items of exemplary embodiments of the present disclosure and does not limit the full scope of the present concept. 1. A marine diesel cylinder lubricant composition comprising (a) a major amount of a lubricating viscosity oil and (b) one or more non-phosphorus oxidized polyalkenyl bis succinimide dispersants, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, and further wherein the marine diesel cylinder lubricant composition has a total base number (TBN) of from about 5 to about 150, said lubricant composition. 2. The marine diesel cylinder lubricant composition according to item 1, having a TBN of from about 5 to about 100. 3. The marine diesel cylinder lubricating oil composition according to item 1, wherein the oil of lubricating viscosity contains a Group I base stock. 4. The marine diesel cylinder lubricating oil composition according to item 1, wherein the oil of lubricating viscosity contains a Group II base stock. 5. The marine diesel cylinder lubricating oil composition according to item 1, wherein the one or more non-phosphorus-containing polyalkenyl bis(succinimide) dispersants are one or more non-phosphorus-containing polyalkenyl bis(succinimide) dispersants in which the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of about 1500 to about 2500. 6. The marine diesel cylinder lubricating oil composition according to item 1, wherein the one or more non-phosphorus-containing polyalkenyl bis(succinimide) dispersants are one or more non-phosphorus-containing polyalkenyl bis(succinimide) dispersants in which the polyalkenyl substituent is derived from a polybutene group having a number average molecular weight of about 1500 to about 3000. 7. The marine diesel cylinder lubricating oil composition according to item 1, wherein the one or more non-phosphorus-containing polyalkenyl bis(succinimide) dispersants are one or more non-phosphorus-containing polyalkenyl bis(succinimide) dispersants in which the polyalkenyl substituent is derived from a polybutene group having a number average molecular weight of about 1500 to about 2500. 8. The marine diesel cylinder lubricating oil composition according to item 1, wherein the one or more non-phosphorus-containing polyalkenyl bis(succinimide) dispersants are present in an amount of about 0.25 to about 10% by weight, based on the active substance, based on the total weight of the marine diesel cylinder lubricating oil composition. 9. The marine diesel cylinder lubricating oil composition according to item 1, wherein the one or more non-phosphorus-containing polyalkenyl bis(succinimide) dispersants are present in an amount of about 1 to about 5% by weight, based on the active substance, based on the total weight of the marine diesel cylinder lubricating oil composition. 10. The marine diesel cylinder lubricating oil composition according to item 1, further comprising one or more additives for marine diesel cylinder lubricating oil compositions selected from the group consisting of antioxidants, detergents, rust inhibitors, anti-fog agents, demulsifiers, metal deactivators, friction modifiers, pour point depressants, defoamers, co-solvents, corrosion inhibitors, dyes, extreme pressure agents, and mixtures thereof. 11. A method of lubricating a marine two-stroke crosshead diesel engine using a marine diesel cylinder lubricant composition having improved oxidation stability, the method comprising operating the engine with a lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity and (b) one or more non-phosphated polyalkenyl bis-succinimide dispersants, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, and further wherein the marine diesel cylinder lubricating oil composition has a total base number (TBN) of from about 5 to about 150. 12. The method according to item 11, wherein the marine diesel cylinder lubricating oil composition has a TBN of from about 5 to about 100. 13. The method according to item 11, wherein the oil of lubricating viscosity comprises a Group I base stock or a Group II base stock. 14. The method according to item 11, wherein the one or more non-phosphated polyalkenyl bis-succinimide dispersants are one or more non-phosphated polyalkenyl bis-succinimide dispersants when the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 2500. 15. The method according to item 11, wherein the one or more non-phosphated polyalkenyl bis-succinimide dispersants are one or more non-phosphated polyalkenyl bis-succinimide dispersants when the polyalkenyl substituent is derived from a polybutene group having a number average molecular weight of from about 1500 to about 3000. 16. The method according to item 11, wherein the one or more non-boronated polyalkenyl bis-succinimide dispersants are one or more non-boronated polyalkenyl bis-succinimide dispersants when the polyalkenyl substituent is derived from a polybutene group having a number average molecular weight of about 1500 to about 2500. 17. The method according to item 11, wherein the one or more non-boronated polyalkenyl bis-succinimide dispersants are present in an amount of about 0.25 to about 10% by weight on an active substance basis based on the total weight of the marine diesel cylinder lubricating oil composition. 18. The method according to item 11, wherein the one or more non-boronated polyalkenyl bis-succinimide dispersants are present in an amount of about 1 to about 5% by weight on an active substance basis based on the total weight of the marine diesel cylinder lubricating oil composition. 19. The method according to item 11, wherein the marine diesel cylinder lubricating oil composition further comprises one or more marine diesel cylinder lubricating oil composition additives selected from the group consisting of antioxidants, detergents, rust inhibitors, cloud point depressants, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoaming agents, auxiliary solvents, corrosion inhibitors, dyes, extreme pressure agents, and mixtures thereof. 20. A marine diesel cylinder lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity and (b) one or more cyclic carbonate post-treated polyalkenyl bis-succinimide dispersants, wherein the marine diesel cylinder lubricating oil composition has a total base number (TBN) of about 5 to about 150. 21. The marine diesel cylinder lubricating oil composition according to item 20, having a TBN of about 5 to about 100. 22. The marine diesel cylinder lubricating oil composition according to item 20, wherein the oil of lubricating viscosity comprises a Group I base stock. 23. The marine diesel cylinder lubricating oil composition according to item 20, wherein the oil of lubricating viscosity comprises a Group II base stock. 24. The marine diesel cylinder lubricating oil composition according to item 20, wherein the one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants are one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants when the polyalkenyl substituent is derived from a polyalkenyl group having a number average molecular weight of about 500 to about 5000. 25. The marine diesel cylinder lubricating oil composition according to item 20, wherein the one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants are one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants when the polyalkenyl substituent is derived from a polyalkenyl group having a number average molecular weight of about 700 to about 3000. 26. The marine diesel cylinder lubricating oil composition according to item 20, wherein the one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants are one or more ethylene carbonate post-treated polyalkenyl bisimide dispersants when the polyalkenyl substituent is derived from a polybutene group having a number average molecular weight of about 500 to about 5000. 27. The marine diesel cylinder lubricating oil composition according to item 20, wherein the one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants are one or more ethylene carbonate post-treated polyalkenyl bisimide dispersants when the polyalkenyl substituent is derived from a polybutene group having a number average molecular weight of about 700 to about 3000. 28. The marine diesel cylinder lubricating oil composition according to item 20, wherein the one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants are present in an amount of about 0.25 to about 10% by weight on an active substance basis based on the total weight of the marine diesel cylinder lubricating oil composition. 29. The marine diesel cylinder lubricating oil composition according to item 20, wherein the one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants are present in an amount of about 1 to about 5% by weight on an active substance basis based on the total weight of the marine diesel cylinder lubricating oil composition. 30. The marine diesel cylinder lubricant composition according to item 20, further comprising at least one additive for marine diesel cylinder lubricant compositions selected from the group consisting of antioxidants, detergents, rust inhibitors, anti-fog agents, demulsifiers, metal deactivators, friction modifiers, pour point depressants, defoamers, co-solvents, corrosion inhibitors, dyes, extreme pressure agents, and mixtures thereof. 31. A method of lubricating a marine two-stroke crosshead diesel engine with a marine diesel cylinder lubricant composition having improved oxidation stability, the method comprising operating the engine with a marine diesel cylinder lubricant composition comprising (a) a major amount of an oil of lubricating viscosity and (b) at least one cyclic carbonate post-treated polyalkenyl bis-succinimide dispersant, wherein the marine diesel cylinder lubricant composition has a total base number (TBN) of from about 5 to about 150. 32. The method according to item 31, wherein the marine diesel cylinder lubricant composition has a TBN of from about 5 to about 100. 33. The method according to item 31, wherein the oil of lubricating viscosity comprises a Group I base stock or a Group II base stock. 34. The method according to item 31, wherein the at least one cyclic carbonate post-treated polyalkenyl bis-succinimide dispersant is at least one cyclic carbonate post-treated polyalkenyl bis-succinimide dispersant in which the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 500 to about 5000. 35. The method according to item 31, wherein the one or more cyclic carbonate post-treated polyalkenyl bis-succinimide dispersants are one or more cyclic carbonate post-treated polyalkenyl bis-succinimide dispersants in which the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 700 to about 3000. 36. The method according to item 31, wherein the one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants are one or more ethylene carbonate post-treated polyalkenyl bisimide dispersants when the polyalkenyl substituent is derived from a polybutene group having a number average molecular weight of about 500 to about 5000. 37. The method according to item 31, wherein the one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants are one or more ethylene carbonate post-treated polyalkenyl bisimide dispersants when the polyalkenyl substituent is derived from a polybutene group having a number average molecular weight of about 700 to about 3000. 38. The method according to item 31, wherein the one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants are present in an amount of about 0.25 to about 10% by weight on an active substance basis based on the total weight of the marine diesel cylinder lubricating oil composition. 39. The method according to item 31, wherein the one or more cyclic carbonate post-treated polyalkenyl bisimide dispersants are present in an amount of about 1 to about 5% by weight on an active substance basis based on the total weight of the marine diesel cylinder lubricating oil composition. 40. The method according to item 31, wherein the marine diesel cylinder lubricating oil composition further comprises one or more marine diesel cylinder lubricating oil composition additives selected from the group consisting of antioxidants, detergents, rust inhibitors, cloud point depressants, demulsifiers, metal deactivators, friction modifiers, pour point depressants, defoamers, auxiliary solvents, corrosion inhibitors, dyes, extreme pressure agents, and mixtures thereof. 41. A marine diesel cylinder lubricating oil composition comprising: (a) a major amount of a Group I base stock oil of lubricating viscosity; and (b) a non-phosphorus oxidized polyalkenyl bisimide dispersant present in an amount of about 1.5 to about 8.0% by weight on an active substance basis based on the total weight of the marine diesel cylinder lubricating oil composition, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of about 1500 to about 3000, and wherein the marine diesel cylinder lubricating oil composition has a total base number (TBN) of about 5 to about 30. 42. The marine diesel cylinder lubricating oil composition according to item 41, wherein the number average molecular weight is from about 1500 to about 2500. 43. The marine diesel cylinder lubricating oil composition according to item 41, wherein the polyalkylene group is a polybutene group. 44. The marine diesel cylinder lubricating oil composition according to item 41, further comprising one or more marine diesel cylinder lubricating oil composition additives selected from the group consisting of antioxidants, detergents, rust inhibitors, cloud point depressants, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoaming agents, auxiliary solvents, corrosion inhibitors, dyes, extreme pressure agents, thickeners, and mixtures thereof. 45. The marine diesel cylinder lubricating oil composition according to item 41, wherein the non-boronated polyalkenyl bis-succinimide dispersant is a cyclic carbonate post-treated polyalkenyl bis-succinimide dispersant. 46. A marine diesel cylinder lubricating oil composition comprising: (a) a major amount of a Group I base stock oil of lubricating viscosity; and (b) a non-boronated polyalkenyl bis-succinimide dispersant present in an amount of from about 1.0 to about 5.0% by weight on an active matter basis, based on the total weight of the marine diesel cylinder lubricating oil composition, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, and further wherein the marine diesel cylinder lubricating oil composition has a total base number (TBN) of greater than about 30. 47. The marine diesel cylinder lubricating oil composition according to item 46, wherein the number average molecular weight is from about 1500 to about 2500. 48. The marine diesel cylinder lubricating oil composition according to item 46, wherein the polyalkylene group is a polybutene group. 49. The marine diesel cylinder lubricating oil composition according to item 46, further comprising one or more marine diesel cylinder lubricating oil composition additives selected from the group consisting of antioxidants, detergents, rust inhibitors, cloud point depressants, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoaming agents, auxiliary solvents, corrosion inhibitors, dyes, extreme pressure agents, thickeners, and mixtures thereof. 50. The marine diesel cylinder lubricating oil composition according to item 46, wherein the non-boronated polyalkenyl bis-succinimide dispersant is a cyclic carbonate post-treated polyalkenyl bis-succinimide dispersant. 51. A marine diesel cylinder lubricating oil composition comprising: (a) a major amount of a Group II base stock oil of lubricating viscosity; and (b) a non-boronated polyalkenyl bis-succinimide dispersant present in an amount of about 1.5 to about 8.0 wt% on an active substance basis, based on the total weight of the marine diesel cylinder lubricating oil composition, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of about 1500 to about 3000, and further wherein the marine diesel cylinder lubricating oil composition has a total base number (TBN) of about 5 to about 20. 52. The marine diesel cylinder lubricating oil composition according to item 51, wherein the number average molecular weight is about 1500 to about 2500. 53. The marine diesel cylinder lubricating oil composition according to item 51, wherein the polyalkylene group is a polybutene group. 54. The marine diesel cylinder lubricating oil composition according to item 51, further comprising one or more marine diesel cylinder lubricating oil composition additives selected from the group consisting of antioxidants, detergents, rust inhibitors, cloud point depressants, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoaming agents, co-solvents, corrosion inhibitors, dyes, extreme pressure agents, thickeners, and mixtures thereof. 55. The marine diesel cylinder lubricating oil composition according to item 51, wherein the non-boronated polyalkenyl bis-succinimide dispersant is a cyclic carbonate post-treated polyalkenyl bis-succinimide dispersant. 56. A diesel cylinder lubricating oil composition for ships, comprising (a) a major amount of a Group II base stock oil having a lubricating viscosity, and (b) a non-phosphorus oxidized polyalkenyl bis succinimide dispersant present in an amount of about 1.0 to about 5.0% by weight on an active substance basis, based on the total weight of the diesel cylinder lubricating oil composition for ships, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of about 1500 to about 3000, and further, the diesel cylinder lubricating oil composition for ships has a total base number (TBN) of more than about 20, said lubricating oil composition. 57. The diesel cylinder lubricating oil composition for ships according to item 56, wherein the number average molecular weight is about 1500 to about 2500. 58. The diesel cylinder lubricating oil composition for ships according to item 56, wherein the polyalkylene group is a polybutene group. 59. The diesel cylinder lubricating oil composition for ships according to item 56, further comprising one or more additives for diesel cylinder lubricating oil compositions for ships selected from the group consisting of antioxidants, detergents, rust inhibitors, cloud point depressants, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoaming agents, auxiliary solvents, corrosion inhibitors, dyes, extreme pressure agents, thickeners, and mixtures thereof. 60. The diesel cylinder lubricating oil composition for ships according to item 56, wherein the polyalkenyl bis succinimide dispersant is a cyclic carbonate post-treated polyalkenyl bis succinimide dispersant. 61. Use of the diesel cylinder lubricating oil composition for ships according to any one of items 41 to 60 in a two-stroke crosshead diesel engine. 62. Use of a cyclic carbonate post-treated polyalkenyl bis succinimide dispersant as an oil thickener for a diesel cylinder lubricating oil composition for ships in an amount of at least 1.0% by weight on an active substance basis.

Claims

1. 1. A marine diesel cylinder lubricating oil composition comprising: (a) a major amount of a Group I base stock oil of lubricating viscosity; and (b) a non-borated polyalkenyl bissuccinimide dispersant present in an amount of from about 1.5 to about 8.0 weight percent, on an active matter basis, based on the total weight of said marine diesel cylinder lubricating oil composition, said polyalkenyl substituent being derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, and further wherein said marine diesel cylinder lubricating oil composition has a total base number (TBN) of from about 5 to about 30.

2. 2. The marine diesel cylinder lubricating oil composition of claim 1, wherein said number average molecular weight is from about 1500 to about 2500.

3. 2. The marine diesel cylinder lubricating oil composition of claim 1, wherein said polyalkene group is a polybutene group.

4. 10. The marine diesel cylinder lubricant composition of claim 1, further comprising one or more marine diesel cylinder lubricant composition additives selected from the group consisting of antioxidants, detergents, rust inhibitors, haze removers, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoam agents, co-solvents, corrosion inhibitors, dyes, extreme pressure agents, and mixtures thereof.

5. 2. The marine diesel cylinder lubricating oil composition of claim 1, wherein the non-borated polyalkenyl bissuccinimide dispersant is a cyclic carbonate post-treated polyalkenyl bissuccinimide dispersant.

6. 1. A marine diesel cylinder lubricating oil composition comprising: (a) a major amount of a Group I base stock oil of lubricating viscosity; and (b) a non-borated polyalkenyl bissuccinimide dispersant present in an amount of from about 1.0 to about 5.0 weight percent, on an active matter basis, based on the total weight of said marine diesel cylinder lubricating oil composition, said polyalkenyl substituent being derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, and further wherein said marine diesel cylinder lubricating oil composition has a total base number (TBN) of greater than about 30.

7. 7. The marine diesel cylinder lubricating oil composition of claim 6, wherein said number average molecular weight is from about 1500 to about 2500.

8. 7. The marine diesel cylinder lubricating oil composition of claim 6, wherein said polyalkylene group is a polybutene group.

9. 7. The marine diesel cylinder lubricant composition of claim 6, further comprising one or more marine diesel cylinder lubricant composition additives selected from the group consisting of antioxidants, detergents, rust inhibitors, haze removers, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoam agents, co-solvents, corrosion inhibitors, dyes, extreme pressure agents and mixtures thereof.

10. 7. The marine diesel cylinder lubricating oil composition of claim 6, wherein said non-borated polyalkenyl bissuccinimide dispersant is a cyclic carbonate post-treated polyalkenyl bissuccinimide dispersant.

11. 1. A marine diesel cylinder lubricating oil composition comprising: (a) a major amount of a Group II base stock oil of lubricating viscosity; and (b) a non-borated polyalkenyl bissuccinimide dispersant present in an amount of from about 1.5 to about 8.0 weight percent, on an active matter basis, based on the total weight of said marine diesel cylinder lubricating oil composition, said polyalkenyl substituent being derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000, and further wherein said marine diesel cylinder lubricating oil composition has a Total Base Number (TBN) of from about 5 to about 20.

12. 12. The marine diesel cylinder lubricating oil composition of claim 11, wherein said number average molecular weight is from about 1500 to about 2500.

13. 12. The marine diesel cylinder lubricating oil composition of claim 11, wherein said polyalkene group is a polybutene group.

14. 12. The marine diesel cylinder lubricant composition of claim 11, further comprising one or more marine diesel cylinder lubricant composition additives selected from the group consisting of antioxidants, detergents, rust inhibitors, haze removers, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoam agents, co-solvents, corrosion inhibitors, dyes, extreme pressure agents and mixtures thereof.

15. 12. The marine diesel cylinder lubricating oil composition of claim 11, wherein said non-borated polyalkenyl bissuccinimide dispersant is a cyclic carbonate post-treated polyalkenyl bissuccinimide dispersant.

16. 1. A marine diesel cylinder lubricating oil composition comprising: (a) a major amount of a Group II base stock oil of lubricating viscosity; and (b) a non-borated polyalkenyl bissuccinimide dispersant present in an amount of from about 1.0 to about 5.0 wt. %, based on a total weight of said marine diesel cylinder lubricating oil composition, on an active matter basis, wherein said polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1500 to about 3000; and further wherein said marine diesel cylinder lubricating oil composition has a total base number (TBN) of greater than about 20.

17. 17. The marine diesel cylinder lubricating oil composition of claim 16, wherein said number average molecular weight is from about 1500 to about 2500.

18. 17. The marine diesel cylinder lubricating oil composition of claim 16, wherein said polyalkene group is a polybutene group.

19. 17. The marine diesel cylinder lubricant composition of claim 16, further comprising one or more marine diesel cylinder lubricant composition additives selected from the group consisting of antioxidants, detergents, rust inhibitors, haze removers, demulsifiers, metal deactivators, friction modifiers, pour point depressants, antifoam agents, co-solvents, corrosion inhibitors, dyes, extreme pressure agents and mixtures thereof.

20. 17. The marine diesel cylinder lubricating oil composition of claim 16, wherein said polyalkenyl bissuccinimide dispersant is a cyclic carbonate post-treated polyalkenyl bissuccinimide dispersant.

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