Marine lubricants for ammonia fired engines with low ZDDP content

Abstract

A marine lubricating oil composition for a non-carbon based fueled marine engine is described. The marine lubricating oil composition includes base oil and total of 900 ppm or less of phosphorous from one or more phosphorous-containing compounds. The composition has a TBN of 200 mg KOH / g or less and meets the specification for SAE J300 revised January 2015 requirements for SAE 20, SAE 30, SAE 40, SAE 50, or SAE 60 monograde lubricating oil.

Description

MARINE LUBRICANTS FOR AMMONIA FIRED ENGINES WITH LOW ZDDP CONTENTCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 691,215, filed September 5, 2024, which is incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] This disclosure relates to marine lubricant additive compositions and lubricating oil compositions containing the same. More particularly, the composition(s) can be used in marine engines that operate using non-carbon based (e.g., ammonia) fuels.BACKGROUND

[0003] Non-carbon based fuels are increasingly being looked at as alternative sources of energy for the propulsion of marine vessels. Utilizing non-carbon based fuels, such as ammonia, requires the development of new engines or possibly the retrofitting of conventional engines to account for differences in the fuel and fuel combustion. Consequently, there is a need to develop lubricating oil formulations that provide unique performance and fuel compatibility in alternative fueled marine engines. In particular, oxidative and thermal stability, as well as deposit control, are important performance aspects which could be impacted as a result of the use of alternative fuels.SUMMARY

[0004] In one aspect, there is provided a marine lubricating oil composition for a non- carbon based fueled marine engine, wherein the marine lubricating oil composition comprises: base oil; and total of 900 ppm or less of phosphorous from one or more phosphorous-containing compounds; wherein the marine lubricating oil composition has a TBN of 200 mg KOH / g or less; and wherein the marine lubricating oil composition meets the specification for SAE J300revised January 2015 requirements for SAE 20, SAE 30, SAE 40, SAE 50, or SAE 60 monograde lubricating oil.

[0005] In another aspect, there is provided a marine lubricating oil composition for an ammonia-fueled marine engine comprising: a base oil; and a phenol-based detergent; wherein the marine lubricating oil composition comprises total of 900 ppm or less of phosphorus from one or more phosphorous-containing compounds; wherein the marine lubricating oil composition has a TBN of 200 mg KOH / g or less; and wherein the marine lubricating oil composition meets the specification for SAE J300 revised January 2015 requirements for SAE 20, SAE 30, SAE 40, SAE 50, or SAE 60 monograde lubricating oil.

[0006] In yet another aspect, there is provided a method of lubricating a low-speed or medium-speed marine diesel engine operated using ammonia fuel, the method comprising: lubricating the low-speed or medium-speed marine diesel engine with a marine lubricating oil composition comprising: a base oil; and a phenol-based detergent; wherein the marine lubricating oil composition comprises total of 900 ppm or less of phosphorous from one or more phosphorous-containing compounds; wherein the marine lubricating oil composition has a TBN of 200 mg KOH / g or less; and wherein the marine lubricating oil composition meets the specification for SAE J30 revised January 2015 requirements for SAE 20, SAE 30, SAE 40, SAE 50, or SAE 60 monograde lubricating oil.DETAILED DESCRIPTION

[0007] It is understood that when combinations, subsets, groups, etc. of elements are disclosed (e.g., combinations of components in a composition, or combinations of steps in a method), that while specific reference of each of the various individual and collective combinations and permutations of these elements may not be explicitly disclosed, each is specifically contemplated and described herein.

[0008] The present disclosure relates to lubricating oil compositions designed for alternative fuel engines (e.g., ammonia fuel) for marine vessels. It has been surprisingly discovered that lubricating oil compositions that contain relatively low levels of phosphorous perform better in several key performance aspects compared to lubricating oil compositions that contain higher levels of phosphorous in an ammonia rich environment.

[0009] In some embodiments, the present disclosure relates to a marine lubricating oil composition for a non-carbon based fueled marine engine, wherein the marine lubricating oil composition comprises base oil; and total of 900 ppm or less of phosphorous from one or more phosphorous-containing compounds; wherein the marine lubricating oil composition has a TBN of 200 mg KOH / g or less; and wherein the marine lubricating oil composition meets the specification for SAE J300 revised January 2015 requirements for SAE 20, SAE 30, SAE 40, SAE 50, or SAE 60 monograde lubricating oil.

[0010] In some embodiments, the marine lubricating oil composition includes a phenol-based detergent. Phenol -based detergents include sulfurized and un-sulfurized calcium phenates, hydroxybenzoates (i.e. carboxylate and salicylate), salixarates and Mannich base of hydrocarbyl-substituted phenol. Preferably, the phenol-based detergent is a calcium phenol- based detergent. Preferably, the calcium phenol -based detergent is a sulfurized or unsulfurized calcium phenate or a calcium hydroxybenzoate detergent.

[0011] The compositions disclosed herein are particularly suitable for ammonia-fueled engines operating under sustained high load conditions. During and after such use, the marine lubricating oil composition of this disclosure should have detectable amounts of ammonia contamination. In some embodiments, the marine lubricating oil composition is contaminated with ammonia.

[0012] In some embodiments, the engine may be a “low-speed” or “slow-speed” marine engine. In some embodiments, the engine may be a two-stroke crosshead compression-ignited engine. The engine can be a novel-design or retrofitted low speed two-stroke marine engine fueled by ammonia. Engines classified as “low-speed” or “slow-speed” may refer to a compression-ignition internal combustion engine that is driven at rotational speed that is less than 500 revolutions per minute (rpm). The diesel engine may also be classified as a “mediumspeed” engine which may be a compression-ignition internal combustion engine that is driven at a rotational speed of 500 to 1800 rpm, such as marine trunk piston diesel engines.

[0013] For purposes of this disclosure, it is understood that the “ammonia-fueled” engine concept for a large bore compression-ignition engine could encompass an engine operated in a dual-fuel mode. In compression-ignition engines, ammonia can be successfully used in a dual-fuel mode with diesel, or another pilot fuel, where ammonia is introduced into a diesel engine via a dual-fuel mode whereby fumigated premixed ammonia (main fuel) in the combustion chamber is ignited by a pilot fuel (e.g. diesel, kerosene, etc.) as an ignition source.

[0014] Some considerations for ammonia-fueled engine formulation include ability to withstand exposure to ammonia and its reactive combustion products (e.g., NO, NO2, H2O) without sacrificing critical performance parameters. In some embodiments, the lubricating oil composition disclosed herein is contaminated with ammonia. In some embodiments, the lubricating oil composition is contaminated with NO, NO2, and / or water.

[0015] In some embodiments, the lubricating oil composition disclosed herein is suitable for use as a marine cylinder lubricant used to lubricate a low-speed crosshead engine. Marine cylinder lubricants are typically made to the SAE 30, SAE 40, SAE 50, or SAE 60 monograde specification (SAE J300 revised January 2015) in order to provide a sufficiently thick lubricant film at the high temperatures on the cylinder liner wall. Typically, marine diesel cylinder lubricants have a TBN of up to 200 mg KOH / g, or ranging from 2 to 200 mg KOH / g (e.g., from 2 to 200 mg KOH / g, from 5 to 200 mg KOH / g, from 10 to 200 mg KOH / g, from 15 to 150 mg KOH / g, from 15 to 60 mg KOH / g, from 20 to 200 mg KOH / g, from 20 to 150mg KOH / g from 20 to 120 mg KOH / g, from 20 to 80 mg KOH / g, from 30 to 200 mg KOH / g, or from 30 to 150 mg KOH / g, or from 30 to 120 mg KOH / g, from 30 to 100 mg KOH / g, from 30 to 80 mg KOH / g, from 60 to 200 mg KOH / g, from 60 to 150 mg KOH / g, from 60 to 120 mg KOH / g, from 60 to 100 mg KOH / g, from 60 to 80 mg KOH / g, from 80 to 200 mg KOH / g, from 80 to 150 mg KOH / g, from 80 to 150 mg 120 KOH / g, from 120 to 200 mg KOH / g, or from 120 to 150 mg KOH / g).

[0016] In some embodiments, the lubricating oil composition disclosed herein is suitable for use as a marine system oil used to lubricate the crankcase of a low-speed crosshead engine. Marine system oil lubricants are typically made to the SAE 20, SAE 30, or SAE 40 monograde specification. The viscosity for the marine system oil is set at relatively low level(s) in part because a system oil can increase in viscosity during use and the engine designers have set viscosity increase limits to prevent operational problems. Typically, marine system oil lubricants have a TBN of up to 12 mg KOH / g or ranging from 2 to 12 mg KOH / g (e.g., from 3 to 12 mg KOH / g, from 5 to 12 mg KOH / g, from 5 to 10 mg KOH / g, or from 5 to 9 mg KOH / g).

[0017] In some embodiments, the lubricating oil composition disclosed herein is suitable for use as a marine trunk piston engine oil (TPEO). Marine TPEO lubricants are typically made to the SAE 30 or SAE 40 monograde specification. Typically, marine TPEO lubricants have a TBN of up to 60 mg KOH / g or ranging from 2 to 60 mg KOH / g (e.g., from 5 to 60 mg KOH / g, 10 to 30 mg KOH / g, from 15 to 60 mg KOH / g, from 15 to 40 mg KOH / g, from 20 to 60 mg KOH / g, 20 to 40 mg KOH / g, from 30 to 60 mg KOH / g, or from 30 to 55 mg KOH / g).

[0018] The term “Total Base Number” or “TBN” or “BN” refers to the level of alkalinity in an oil sample, which indicates the ability of the composition to continue to neutralize corrosive acids, in accordance with ASTM Standard No. D2896 or equivalentprocedure. The test measures the change in electrical conductivity, and the results are expressed as mg KOH / g (the equivalent number of milligrams of KOH needed to neutralize 1 gram of a product). Therefore, a high TBN reflects strongly overbased products and, as a result, a higher base reserve for neutralizing acids. TBN values are represented in units of mg KOH / g.

[0019] The term “on an actives basis” refers to additive material that is not diluent oil or solvent. All concentrations should be considered on an actives basis unless stated otherwise. Base Oil

[0020] The lubricating oil composition of the present invention includes one or more base oils. These include, for example, Group I, II, III, IV, or V base oils, and biobased base oils. Preferably, the base oil is Group II, III, IV, or V. Examples of suitable biobased base oils are described in US Patent Pub No. 20230167378, which is hereby incorporated by reference.

[0021] Base stocks may be manufactured using a variety of different processes including, but not limited to, distillation, solvent refining, hydrogen processing, oligomerization, esterification, and re-refining. Re-refined stock shall be substantially free from materials introduced through manufacturing, contamination, or previous use. The base oil of the lubricating oil compositions of this invention may be any natural or synthetic lubricating base oil. Suitable hydrocarbon synthetic oils include, but are not limited to, oils prepared from the polymerization of ethylene or from the polymerization of 1 -olefins to provide polymers such as polyalphaolefin or PAO oils, or from hydrocarbon synthesis procedures using carbon monoxide and hydrogen gases such as in a Fischer-Tropsch process.

[0022] Moreover, the one or more base oils may include base oils from the same group (e.g., Group II Chevron Neutral Oil 600R®, Group II Chevron Neutral Oil 220R® and Group II Chevron Neutral Oil 100R®). The one or more base oils may include base oils from different groups (e.g., mixture of Group I and Group II). The amount of base oil(s) is about 40 wt. % or greater (“a major amount”) based on the total weight of the lubricating oil composition, suchas from about 45 wt. % or greater, 50 wt. % or greater, 55 wt. % or greater, 60 wt. % or greater, and so forth.

[0023] Groups I, II, III, IV and V are broad categories of base oil stocks developed and defined by the American Petroleum Institute (API Publication 1509 — Appendix E) to create guidelines for lubricant base oils. Group I base stocks contain less than 90% saturates and / or greater than 0.03% sulfur and have a viscosity index greater than or equal to 80 and less than 120. Group II base stocks (and higher) contain greater than or equal to 90% saturates and less than or equal to 0.03% sulfur and have a viscosity index greater than or equal to 80 and less than 120. Group III base stocks contain greater than or equal to 90% saturates and less than or equal to 0.03% sulfur and have a viscosity index greater than or equal to 120. Group IV base stocks are polyalphaolefins. Group V base stocks include all other base stocks not included in Groups I, II, III or IV.Base Oil PropertiesGroup(1)Saturates(2)Viscosity Index(4)Group I < 90% and / or > 0.03% 80 to < 120Group II > 90%80 to < 120Group III > 90%> 120Group IV Polyalphaolefins (PAOs)Group V All other base stocks not included in Groups I, II,III, or IV(1) Group I-III are mineral oil base stocks(2) ASTM D2007(3) ASTM D2622, ASTM D3120, ASTM D4294 or ASTM D4927(4) ASTM D2270Lubricating Oil Composition

[0024] The lubricating oil composition of this disclosure can be identified by viscosity standards of the Society of Automotive Engineers (SAE) for engine oils (i.e., the SAE J300 standard). The SAE J300 viscosity grades are summarized in Table 1.Table 1(2) ASTM D4684(3) ASTM D445(4) ASTM D4683, ASTM D4741, ASTM D5481 or CEC L-36-90(5) For 0W-40, 5W-40 and 10W-40 grades(6) For 15W-40, 20W-40, 25W-40 and 40 grades

[0025] The lubricating oil composition of this disclosure may be a monograde engine oil, e.g., a SAE 20, SAE 30, SAE 40, SAE 50 or SAE 60 viscosity grade engine oil. Lubricating Oil Additives

[0026] The lubricating oil compositions of the present disclosure may contain one or more performance additives that can impart or improve any desirable property of the lubricating oil composition. Any additive known to those of skill in the art may be used in the lubricating oil composition disclosed herein. Some suitable additives have been described by R. M. Mortier et al. “Chemistry and Technology of Lubricants,” 3rd Edition, Springer (2010) and L. R. Rudnik “Lubricant Additives: Chemistry and Applications,” Second Edition, CRC Press (2009).

[0027] In general, the concentration of each of the additives in the lubricating oil composition, when used, may range from 0.001 to 60 wt. % (e.g., 0.01 to 50 wt. %, or 0.05 to 40 wt. %) of the lubricating oil composition. Further, the total amount of additives in the lubricating oil composition may range from 0.001 to 70 wt. % (e.g., 0.01 to 50 wt. % or 0.1 to 40 wt. %) of the lubricating oil composition.Antioxidants

[0028] Antioxidants retard the oxidative degradation of base oils during service. Such degradation may result in deposits on metal surfaces, the presence of sludge, or a viscosity increase in the lubricant. Useful antioxidants include hindered phenols, aromatic amines, and sulfurized alkylphenols and alkali and alkaline earth metal salts thereof.

[0029] The hindered phenol antioxidant may contain a secondary butyl and / or a tertiary butyl group as a sterically hindering group. The phenol group may be further substituted with a hydrocarbyl group and / or a bridging group linking to a second aromatic group. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert- butylphenol, 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 4,4'-bis(2,6-di-tert-butylphenol)and 4,4'-methylenebis(2,6-di-tert-butylphenol). The hindered phenol antioxidant may be an ester or an addition product derived from 2,6-di-tert-butylphenol and an alkyl acrylate, wherein the alkyl group may contain from 1 to 18 carbon atoms.

[0030] Suitable aromatic amine antioxidants include diarylamines such as alkylated diphenylamines (e.g., dioctyl diphenylamine, dinonyl diphenylamine), phenyl-alpha- naphthalene and alkylated phenyl-alpha-naphthalenes.Phosphorous-Containing Compounds

[0031] The marine lubricating oil composition of this disclosure comprises 900 ppm or less of phosphorous. The phosphorous may be sourced from a phosphorous-containing compound such as zinc dithiophosphate (ZDDP), ashless dithiophosphate, and the like.

[0032] The zinc dithiophosphate may have the following formula: Zn[S-P(=S)(OR1)(OR2)]2, wherein R1and R2may be the same or different hydrocarbyl radicals having from 1 to 18 (e.g., 2 to 12) carbon atoms and including radicals such as alkyl, alkenyl, aryl, arylalkyl, alkaryl and cycloaliphatic radicals. The R1and R2groups may be alkyl groups having from 2 to 8 carbon atoms (e.g., the alkyl radicals may be ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n- pentyl, isopentyl, n-hexyl, isohexyl, or 2-ethylhexyl). The zinc dihydrocarbyl dithiophosphate can therefore include zinc dialkyl dithiophosphates (ZDDP). The zinc dialkyl dithiophosphate can be a primary ZnDTP containing primary alkyl groups, or secondary zinc dialkyl dithiophosphate containing secondary alkyl groups, or mixtures thereof.Additional Anti-Wear Agents

[0033] Additional phosphorous-containing anti-wear agents include other phosphorus- containing anti-wear / extreme pressure agents such as thiophosphates, phosphoric acid estersand salts thereof, phosphorus-containing carboxylic acids, esters, ethers, and amides; and phosphites. The anti-wear agent may be a zinc dialkyldithiophosphate. Non-phosphorus- containing anti-wear agents include borate esters (including borated epoxides), dithiocarbamate compounds, molybdenum-containing compounds, and sulfurized olefins.

[0034] In one embodiment, the lubricating oil composition of the invention does not contain a phosphorus containing additive. In one embodiment, the lubricating oil composition of the invention does not contain a phosphorous containing anti-wear additive. In one embodiment, the lubricating oil composition of the invention comprises less than or equal to 900 ppm of phosphorous. In one embodiment, the lubricating oil composition of the invention is phosphorous-free. In one embodiment, the lubricating oil composition of the invention is free of zinc dithiophosphate.

[0035] In one embodiment, the level of phosphorus in the lubricating oil compositions of the present invention is less than or equal to about 0.09 wt. %, based on the total weight of the lubricating oil composition, such as a level of phosphorus of about 0.001 wt. % to about 0.09 wt. %. In one embodiment, the levels of phosphorus in the lubricating oil compositions of the present invention is less than or equal to about 0.085 wt. %, based on the total weight of the lubricating oil composition, e.g., a level of phosphorus of about 0.001 wt. % to about 0.085 wt. %. In one embodiment, the levels of phosphorus in the lubricating oil compositions of the present invention is less than or equal to about 0.08 wt. %, based on the total weight of the lubricating oil composition, e.g., a level of phosphorus of about 0.001 wt. % to about 0.08 wt. %. In one embodiment, the levels of phosphorus in the lubricating oil compositions of the present invention is less than or equal to about 0.075 wt. %, based on the total weight of the lubricating oil composition, e.g., a level of phosphorus of about 0.001 wt. % to about 0.075 wt. %. In one embodiment, the levels of phosphorus in the lubricating oil compositions of the present invention is less than or equal to about 0.07 wt. %, based on the total weight of thelubricating oil composition, e.g., a level of phosphorus of about 0.001 wt. % to about 0.07 wt. %. In one embodiment, the levels of phosphorus in the lubricating oil compositions of the present invention is less than or equal to about 0.065 wt. %, based on the total weight of the lubricating oil composition, e.g., a level of phosphorus of about 0.001 wt. % to about 0.065 wt. %. In one embodiment, the levels of phosphorus in the lubricating oil compositions of the present invention is less than or equal to about 0.06 wt. %, based on the total weight of the lubricating oil composition, e.g., a level of phosphorus of about 0.001 wt. % to about 0.06 wt. %. In one embodiment, the levels of phosphorus in the lubricating oil compositions of the present invention is less than or equal to about 0.055 wt. %, based on the total weight of the lubricating oil composition, e.g., a level of phosphorus of about 0.001 wt. % to about 0.055 wt. %. In one embodiment, the levels of phosphorus in the lubricating oil compositions of the present invention is less than or equal to about 0.05 wt. %, based on the total weight of the lubricating oil composition, e.g., a level of phosphorus of about 0.001 wt. % to about 0.05 wt. %.Metal Detergents

[0036] A typical detergent is an anionic material that contains a long chain hydrophobic portion of the molecule and a smaller anionic or oleophobic hydrophilic portion of the molecule. The anionic portion of the detergent is typically derived from an organic acid such as a sulfur acid, carboxylic acid, phosphorous acid, phenol, or mixtures thereof. The counterion is typically an alkaline earth or alkali metal.

[0037] In some embodiments, the lubricating oil composition provided herein comprises at least a neutral or overbased metal detergent as an additive, or additive components. In certain embodiments, the metal detergents in lubricating oil compositions actsas a neutralizer of acidic products within the oil. In certain embodiments, the metal detergent prevents the formation of deposits on the surface of an engine. Depending on the nature of the acid used, the detergent may have additional functions, for example, antioxidant properties. In certain aspects, lubricating oil compositions contain metal detergents comprising either overbased detergents or mixtures of neutral and overbased detergents. The term “overbased” is intended to define additives which contain a metal content in excess of that required by the stoichiometry of the particular metal and the particular organic acid used. The excess metal exists in the form of particles of inorganic base (e.g., a hydroxide or carbonate) surrounded by a sheath of metal salt. The sheath serves to maintain the particles in dispersion in a liquid oleaginous vehicle. The amount of excess metal is commonly expressed as the ratio of total equivalence of excess metal to equivalence of organic acid and is typically in a range of 0.1 to 30.

[0038] Overbased detergents may be further characterized as low overbased, medium overbased, or high overbased. Low overbased detergents may be, for example, an overbased salt having a TBN below 120. In one embodiment, the TBN of a low overbased salt may be from about 5 to about 110, from about 5 to 100, from about 5 to 50. In another embodiment, the TBN of a low overbased salt may be from about 10 to about 30. In yet another embodiment, the TBN of a low overbased salt may be from about 15 to about 20.

[0039] Medium overbased detergents, may be, for example, an overbased salt having a TBN from about 120 to about 250. In one embodiment, the TBN of a medium overbased salt may be from about 120 to about 200. In another embodiment, the TBN of a medium overbased salt may be from about 120 to about 175.

[0040] High overbased detergents may be, for example, an overbased salt having a TBN above 250. In one embodiment, the TBN of a high overbased salt may be from about 250 to about 800.

[0041] Some examples of suitable metal detergents include sulfurized or unsulfurized alkyl or alkenyl phenates, alkyl or alkenyl aromatic sulfonates, borated sulfonates, sulfurized or unsulfurized metal salts of multi-hydroxy alkyl or alkenyl aromatic compounds, alkyl or alkenyl hydroxy aromatic sulfonates, sulfurized or unsulfurized alkyl or alkenyl naphthenates, metal salts of alkanoic acids, metal salts of an alkyl or alkenyl multiacid, and chemical and physical mixtures thereof. Other examples of suitable metal detergents include metal sulfonates, phenates, salicylates (i.e. carboxylates, hydroxybenzoates), phosphonates, thiophosphonates and combinations thereof. The metal can be any metal suitable for making sulfonate, phenate, salicylate or phosphonate detergents. Non-limiting examples of suitable metals include alkali metals, alkaline metals and transition metals. In some embodiments, the metal is Ca, Mg, Ba, K, Na, Li or the like. An exemplary metal detergent which may be employed in the lubricating oil compositions includes overbased calcium phenol-based detergent. In one embodiment the preferred calcium phenol-based detergent is an overbased calcium sulfurized or unsulfurized phenate detergent or an overbased calcium hydroxybenzoate detergent.

[0042] In one embodiment, the lubricating oil composition contains a phenol-based detergent. Suitable examples of phenol-based detergents include metal salts of phenols and sulfurized phenols (e.g., phenate or sulfurized phenate detergents or calcium sulfurized phenate detergents) are prepared by reaction of the phenol or sulfurized phenol with an appropriate metal compound such as an oxide or hydroxide. Sulfurized phenols may be prepared by reacting a phenol with sulfur or a sulfur containing compound such as hydrogen sulfide, sulfur monohalide or sulfur dihalide, to form products which are generally mixtures of compounds in which two or more phenols are bridged by sulfur-containing bridges. Additional details regarding the general preparation of sulfurized phenates can be found in, for example, U.S. Pat. Nos. 2,680,096; 3,178,368 and 3,801,507, the contents of which are incorporated herein byreference. In one embodiment, the lubricating oil composition of the invention includes an overbased calcium phenol-based detergent.

[0043] The sulfur employed for formation of a sulfurized compound may have any allotropic form of sulfur. The sulfur may be present either as molten sulfur or as a solid (e.g., powder or particulate) or as a solid suspension in a compatible hydrocarbon liquid.

[0044] In some embodiments, it is desirable to use calcium hydroxide as the calcium base because of its handling convenience versus, for example, calcium oxide, and also because it affords excellent results. Other calcium bases can also be used, for example, calcium alkoxides and calcium dioxide.

[0045] Suitable alkylphenols which can be used are those wherein the alkyl substituents contain a sufficient number of carbon atoms to render the resulting alkylphenate (e.g., overbased sulfurized calcium alkylphenate) composition oil-soluble. Oil solubility may be provided by a single long chain alkyl substitute or by a combination of alkyl substituents. Typically, the alkylphenol used in will be a mixture of different alkylphenols, e.g., C20 to C24 alkylphenol. In one embodiment, suitable alkyl phenolic compounds will be derived from isomerized normal alpha olefin alkyl groups having from about 10 to about 40 carbon atoms per molecule, having an isomerization level of the alpha olefin between from about 0.1 to about 0.4. Isomerization level can be determined by the method described in US11485928, the contents of which are incorporated herein by reference. In one embodiment, the isomerized normal alpha olefins have from about 20 to about 24 carbon atoms.

[0046] In one embodiment, suitable alkyl phenolic compounds will be derived from alkyl groups which are branched olefinic propylene oligomers or mixture thereof having from about 9 to about 80 carbon atoms. In one embodiment, the branched olefinic propylene oligomer or mixtures thereof have from about 9 to about 40 carbon atoms. In one embodiment, the branched olefinic propylene oligomer or mixtures thereof have from about 9 to about 18carbon atoms. In one embodiment, the branched olefinic propylene oligomer or mixtures thereof have from about 9 to about 12 carbon atoms.

[0047] In one embodiment, suitable alkyl phenolic compounds include distilled cashew nut shell liquid (CNSL) or hydrogenated, distilled CNSL. Distilled CNSL is a mixture of biodegradable meta-hydrocarbyl substituted phenols, where the hydrocarbyl group is linear and unsaturated, including cardanol. Catalytic hydrogenation of distilled CNSL gives rise to a mixture of meta-hydrocarbyl substituted phenols predominantly rich in 3 -pentadecylphenol.

[0048] The alkylphenols can be para-alkylphenols, meta-alkylphenols or ortho alkylphenols. In certain embodiments, such as where overbased products are desired, the alkylphenol is preferably predominantly a para alkylphenol with no more than about 45 mole percent of the alkylphenol being ortho alkylphenols; and more preferably no more than about 35 mole percent of the alkylphenol is ortho alkylphenol. Alkyl-hydroxy toluenes or xylenes, and other alkyl phenols having one or more alkyl substituents in addition to at least one long chained alkyl substituent can also be used. In the case of distilled cashew nut shell liquid, the catalytic hydrogenation of distilled CNSL gives rise to a mixture of meta-hydrocarbyl substituted phenols.

[0049] In general, the selection of alkylphenols can be based on the properties desired for the marine engine lubricating oil compositions, notably TBN, and oil solubility. Additional information regarding preparation of suitable alkylphenols can be found, for example, in U.S. Pat. Nos. 5,024,773, 5,320,763; 5,318,710; and 5,320,762, each of which are incorporated herein by reference.

[0050] In one or more embodiments, the lubricating oil composition includes a phenol- based detergent which is an overbased sulfurized calcium phenate detergent. In one or more embodiments, the lubricating oil composition includes an overbased sulfurized calcium phenate detergent having a TBN of less than 250 mg KOH / g. In one or more embodiments,the lubricating oil composition includes an overbased sulfurized calcium phenate detergent that is not derived from tetrapropenyl phenol. In one or more embodiments, the lubricating oil composition includes a phenol-based detergent which is an overbased sulfurized calcium phenate detergent derived from isomerized normal alpha olefin alkyl groups having from about 10 to about 40 carbon atoms per molecule. The overbased calcium salt of a phenate detergent can be prepared any compatible method such as described in, for example, U.S. Patent No. 8,580,717 which is herein incorporated in its entirety.

[0051] Other suitable examples of phenol -based detergents are metal salts of alkylsubstituted hydroxyaromatic hydroxybenzoate (carboxylates).

[0052] In one embodiment, the metal salts of alkyl substituted hydroxyaromatic hydroxybenzoate is an alkaline earth metal alkyl -substituted hydroxyaromatic carboxylate which contains a single type of anion as a surfactant for the additive, for example, a member or members of the alkyl salicylate group, and does not contain a member or members of the sulfonate group, or a member of members of the phenate group, other than phenate that is derived from inherent phenol which is a result of the process to manufacture salicylate.

[0053] In one embodiment, the overbased alkaline earth metal alkyl -substituted hydroxyaromatic carboxylate detergent is not a complex, or hybrid, detergent which is known in the art as comprising a surfactant system derived from at least two surfactants described above.

[0054] In one embodiment, the alkaline earth metal alkyl-substituted hydroxyaromatic carboxylate can be represented by the following structure (1):wherein each R is independently an alkyl substituent and is a hydrocarbyl group. There may be more than one R group attached to the benzene ring. The COOM (M = Ca) group can be in the ortho, meta or para position with respect to the hydroxyl group; the ortho position is preferred. The R group can be in the ortho, meta or para position with respect to the hydroxyl group. In some embodiments, R is a linear or branched aliphatic group. In some embodiments, R is an isomerized olefin.

[0055] The alkyl substituent of the overbased alkaline earth metal alkyl -substituted hydroxyaromatic carboxylate may be a residue derived from an isomerized normal alpha-olefin having from 12 to 40 carbon atoms. In one embodiment, the alkyl substituent is a residue derived from an isomerized alpha-olefin having from 14 to 28 carbon atoms per molecule. In one embodiment, the alkyl substituent is a residue derived from an isomerized alpha-olefin having from 14 to 18 carbon atoms per molecule. In one embodiment, the alkyl substituent is a residue derived from an isomerized alpha-olefin having from 20 to 28 carbon atoms per molecule. In one embodiment, the alkyl substituent is a residue derived from an isomerized alpha-olefin having from 20 to 24 carbon atoms per molecule. In one embodiment, the alkyl substituent is a residue derived from an olefin comprising C12 to C40 oligomers of a monomer selected from propylene, butylene, or mixtures thereof. Examples of such olefins include propylene tetramer, butylene trimer, isobutylene oligomers, and the like. The olefins employedmay be linear, isomerized linear, branched or partially branched linear. The olefin may be a mixture of linear olefins, a mixture of isomerized linear olefins, a mixture of branched olefins, a mixture of partially branched linear or a mixture of any of the foregoing. The alpha-olefin may be a normal alpha-olefin, an isomerized normal alpha-olefin, or a mixture thereof.

[0056] In one embodiment where the alkyl substituent is a residue derived from an isomerized alpha-olefin, the alpha-olefin can have an isomerization level (I) of 0.1 to 0.4 (e.g., 0.1 to 0.3, or 0.1 to 0.2). The isomerization level (7) can be determined byJH NMR spectroscopy and represents the relative amount of methyl groups (-CH3) (chemical shift 0.30- 1.01 ppm) attached to the methylene backbone groups (-CH2-) (chemical shift 1.01-1.38 ppm) and is defined by the following formula:I = ml (m+ri) where m is theJH NMR integral for methyl groups with chemical shifts between 0.30 ± 0.03 to 1.01 ± 0.03 ppm, and n is theJH NMR integral for methylene groups with chemical shifts between 1.01 ± 0.03 to 1.38 ± 0.10 ppm.

[0057] Overbased alkaline earth metal alkyl -substituted hydroxyaromatic carboxylates may be prepared by methods known in the art, such as described, for example, in U.S. Patent Nos. 8,030,258 and 8,993,499.

[0058] In one embodiment, the phenol-based detergent is an alkaline earth metal alkylsubstituted hydroxyaromatic carboxylate or an alkaline earth metal alkyl -substituted sulfurized or unsulfurized phenate detergent where the alkyl substituent is a residue derived from a C20- C24 isomerized alpha-olefin, the alpha-olefin can have an isomerization level (7) of 0.1 to 0.4.

[0059] The phenol-based detergent may be the calcium salt of a Mannich hydrocarbyl- substituted phenol. This Mannich product may be synthesized by any compatible method including via the reaction of a hydrocarbyl -substituted phenol with formaldehyde and a primaryamine. The resulting product is then mixed with calcium hydroxide (lime) to form the calcium salt of the Mannich base hydrocarbyl -substituted phenol.

[0060] As noted, certain embodiments of lubricating oil formulations may utilize one or more sulfonate detergents, either alone or in combination with other sulfonates (e.g. combination of high overbased sulfonate and low overbased sulfonate) and other detergents. Sulfonates may be prepared from sulfonic acids which may be obtained by the sulfonation of alkyl substituted aromatic hydrocarbons such as those obtained from the fractionation of petroleum or by the alkylation of aromatic hydrocarbons. Examples of alkyl substituted aromatic hydrocarbons which may be sulfonated include those obtained by alkylating benzene, toluene, xylene, naphthalene, diphenyl or their halogen derivatives. The alkylation may be carried out in the presence of a catalyst with alkylating agents having from 3 to more than 70 carbon atoms. The alkaryl sulfonates usually contain from 9 to 80 or more carbon atoms, preferably from 16 to 60, preferably from 16 to 30, most preferably from 20 to 24carbon atoms per alkyl substituted aromatic moiety.

[0061] In one embodiment, the lubricating oil formulations may utlitize a combination of high overbased sulfonate and low overbased sulfonate derived from alkylation of toluene.

[0062] The oil soluble sulfonates or alkaryl sulfonic acids may be neutralized with oxides, hydroxides, alkoxides, carbonates, carboxylate, sulfides, hydrosulfides, nitrates, borates and ethers of the metal. The amount of metal compound is chosen having regard to the desired TBN of the final product.

[0063] Detergents may also include “hybrid” or “complex” detergents formed with mixed surfactant systems including phenate and / or sulfonate components, e.g., phenate / salicylates, sulfonate / phenates, sulfonate / salicylates, sulfonate / phenate / salicylates, as described for example in US Patents 6,429,178; 6,429,179; 6,153,565. Detergents may also include methylene-bridged polyphenol compositions prepared from the reaction of phenol withformaldehyde, or a reversible polymer thereof, optionally sulfurizing the methylene-bridged intermediate and subsequently reacting the intermediate with an excess of a metal base to produce a methylene bridged polyphenol phenate composition. In one embodiment the methylene bridged polyphenol phenate composition may be further reacted with an epoxide. In one embodiment the methylene bridged polyphenol phenate composition is not sulfurized.

[0064] In one or more embodiments, the lubricating oil composition includes a low overbased calcium sulfonate detergent, a medium overbased calcium sulfonate detergent, and / or a high overbased calcium sulfonate detergent, or combinations thereof, which is present in an amount to provide a sulfonate soap content in the lubricating oil composition of 10 mmol / kg sulfonate soap or greater (e.g., 10 mmol / kg to 140 mmol / kg, 10 mmol / kg to 100 mmol / kg, 10 mmol / kg to 80 mmol / kg, 25 mmol / kg to 140 mmol / kg, 30 mmol / kg to 140 mmol / kg, 30 mmol / kg to 100 mmol / kg, 40 mmol / kg to 100 mmol / kg, 40 mmol / kg to 80 mmol / kg, or 50 mmol / kg to 100 mmol / kg sulfonate soap) to the lubricant composition.

[0065] In one or more embodiments, the lubricating oil composition includes a low overbased calcium sulfonate detergent, a medium overbased calcium sulfonate detergent, and / or a high overbased calcium sulfonate detergent, or combinations thereof, wherein the TBN contribution from sulfonate detergents to total detergent BN contribution is greater than about 20%; and further wherein the sulfonate detergents is present in an amount to provide a sulfonate soap content of 25 mmol / kg to 140 mmol / kg in the lubricating oil composition.

[0066] In one or more embodiments, the lubricating oil composition includes a low overbased calcium sulfonate detergent, a medium overbased calcium sulfonate detergent, and / or a high overbased calcium sulfonate detergent, or combinations thereof, wherein the TBN contribution from sulfonate detergents to total detergent BN contribution is 20 to 95%; and further wherein the sulfonate detergents is present in an amount to provide a sulfonate soap content of 25 mmol / kg to 140 mmol / kg in the lubricating oil composition.

[0067] In one embodiment, the contribution from the phenol-based detergent can be from one or more phenol-based detergents with similar or different TBN levels. In one embodiment, the sulfonate soap contribution can be from one or more sulfonate detergents with similar or different TBN levels (e.g. combination of low overbased and high overbased).

[0068] Generally, the amount of the detergent can be from about 0.001 wt. % to about 60 wt. %, such as from about 0.05 wt.% to about 40 wt.%, such as about 0.05 wt.% to about 30 wt. %, such as from about 0.05 wt. % to about 25 wt. %, from about 0.1 wt. % to about 20 wt. %, from about 0.01 to 15 wt. %, and from about 0.01 to about 10 wt. % based on the total weight of the marine lubricating oil composition. Other additional detergents can be present in the lubricating oil composition at any appropriate amount, such as at 0.1 to 45 wt. %, or at 0.5 to 30 wt. % of the lubricating oil composition.Ashless Dispersants

[0069] A dispersant is an additive whose primary function is to hold solid and liquid contaminations in suspension, thereby passivating them and reducing engine deposits at the same time as reducing sludge depositions. For example, a dispersant maintains in suspension oil-insoluble substances that result from oxidation during use of the lubricant, thus preventing sludge flocculation and precipitation or deposition on metal parts of the engine.

[0070] Dispersants are usually “ashless”, being non-metallic organic materials that form substantially no ash on combustion, in contrast to metal -containing, and hence ashforming materials. They comprise a long hydrocarbon chain with a polar head, the polarity being derived from inclusion of at least one nitrogen, oxygen or phosphorus atom. The hydrocarbon is an oleophilic group that confers oil -solubility, having, for example, 40 to 500 carbon atoms. Thus, ashless dispersants may comprise an oil-soluble polymeric backbone.

[0071] A preferred class of olefin polymers is constituted by polybutylenes, specifically polyisobutylenes (PIB) or poly-n-butylenes, such as may be prepared by polymerization of a C4 refinery stream.

[0072] Dispersants include, for example, derivatives of long chain hydrocarbonsubstituted carboxylic acids, examples being derivatives of high molecular weight hydrocarbyl-substituted succinic acid. A noteworthy group of dispersants is constituted by hydrocarbon-substituted succinimides, made, for example, by reacting the above acids (or derivatives) with a nitrogen-containing compound, advantageously a polyalkylene polyamine, such as a polyethylene polyamine. Typical commercially available polyisobutylene-based succinimide dispersants contain polyisobutylene polymers having a number average molecular weight ranging from 900 to 2500, functionalized by maleic anhydride, and derivatized with polyamines having a molecular weight of from 100 to 350.

[0073] Other suitable dispersants include succinic esters and ester-amides, Mannich bases, polyisobutylene succinic acid (PIBSA), and other related components.

[0074] Succinic esters are formed by the condensation reaction between hydrocarbonsubstituted succinic anhydrides and alcohols or polyols. For example, the condensation product of a hydrocarbon-substituted succinic anhydride and pentaerythritol is a useful dispersant.

[0075] Succinic ester-amides are formed by condensation reaction between hydrocarbon-substituted succinic anhydrides and alkanol amines. For example, suitable alkanol amines include ethoxylated polyalkylpolyamines, propoxylated polyalkylpolyamines and polyalkenylpolyamines such as polyethylene polyamines. One example is propoxylated hexamethyl enedi amine .

[0076] Mannich bases are made from the reaction of an alkylphenols, formaldehyde, and a polyalkylene polyamines. Molecular weights of the alkylphenol may range from 800 to 2500.

[0077] Nitrogen-containing dispersants may be post-treated by conventional methods to improve their properties by reaction with any of a variety of agents. Among these are boron compounds (e.g., boric acid) and cyclic carbonates (e.g., ethylene carbonate).

[0078] In one embodiment, the dispersant is 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. In one embodiment, the dispersant is non-borated post-treated polyalkenyl bis-succinimide dispersant. In one embodiment the dispersant is post-treated with ethylene carbonate. In one embodiment the dispersant is a non post-treated polyalkenyl bis-succinimide dispersant, wherein the polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 1000 to about 1500. In one embodiment the dispersant is present in the lubricating composition from 0.05 to 10.0 wt.% (e.g., 0.1 to 10.0 wt.%, 0.1 to 5.0 wt.%, 0.2 to 10 wt.%, or 0.2 to 5.0 wt.%).Friction Modifiers

[0079] A friction modifier is any material or materials that can alter the coefficient of friction of a surface lubricated by any lubricant or fluid containing such material(s). Friction modifiers include alkoxylated fatty amines, borated fatty epoxides, fatty phosphites, fatty epoxides, fatty amines, borated alkoxylated fatty amines, metal salts of fatty acids, fatty acid amides, glycerol esters, borated glycerol esters and fatty imidazolines. As used herein, the term “fatty” means a hydrocarbon chain having 10 to 22 carbon atoms, typically a straight hydrocarbon chain.

[0080] Other known friction modifiers comprise oil-soluble organo-molybdenum compounds. Such organo-molybdenum friction modifiers also provide antioxidant and antiwear credits to a lubricating oil composition. Suitable oil-soluble organo-molybdenumcompounds have a molybdenum-sulfur core. As examples, there may be mentioned dithiocarbamates, dithiophosphates, dithiophosphinates, xanthates, thioxanthates, sulfides, and mixtures thereof. The molybdenum compound may be dinuclear or trinuclear.Corrosion Inhibitors

[0081] Corrosion inhibitors protect lubricated metal surfaces against chemical attack by water or other contaminants. Suitable corrosion inhibitors include polyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, thiadiazoles and anionic alkyl sulfonic acids.Viscosity Modifiers

[0082] Viscosity modifiers provide lubricants with high and low temperature operability. These additives increase the viscosity of the oil composition at elevated temperatures which increases film thickness, while having limited effect on viscosity at low temperatures.

[0083] Suitable viscosity improvers include high molecular weight hydrocarbons, polyesters and viscosity index improver dispersants that function as both a viscosity index improver and a dispersant. Typical molecular weights of these polymers are in a range of 1000 to 1,000,000 (e.g., 2000 to 500,000 or 25,000 to 100,000).

[0084] Examples of suitable viscosity improvers are polymers and copolymers of methacrylate, butadiene, olefins, or alkylated styrenes. Polyisobutylene is a commonly used viscosity modifier. Another suitable viscosity modifier is polymethacrylate (copolymers of various chain length alkyl methacrylates, for example), some formulations of which also serve as pour point depressants. Other suitable viscosity modifiers include copolymers of ethylene and propylene, hydrogenated block copolymers of styrene and isoprene, and polyacrylates(copolymers of various chain length acrylates, for example). Specific examples include styrene-isoprene or styrene-butadiene based polymers of 50,000 to 200,000 molecular weight.Pour Point Depressants

[0085] Pour point depressants lower the minimum temperature at which a fluid will flow or can be poured. Suitable pour point depressants include C8 to C18 dialkyl fumarate / vinyl acetate copolymers, polyalkylmethacrylates and the like.Foam Inhibitors

[0086] Foam inhibitors retard the formation of stable foams. Examples of suitable foam inhibitors include polysiloxanes, polyacrylates, and the like.Thickener

[0087] A thickener can increase the viscosity of a lubricating oil composition in order to achieve a desired viscosity grade. Any suitable thickener such as bright stock (BS), polyisobutylene (PIB), polymethacrylate (PMA), or olefin copolymer (OCP) may be used.

[0088] PIB is a commercially available material from several manufacturers. Polyisobutylene is typically a viscous oil-miscible liquid having a number average molecular weight of 800 to 5000 (e.g., 1000 to 2500) and a kinematic viscosity at 100° C. of 200 to 5000 mm2 / s (e.g., 200 to 1000 mm2 / s). The amount of PIB added to the lubricating oil composition will normally be from 1 to 20 wt. % (e.g., 2 to 15 wt. % or 4 to 12 wt. % on an actives basis) of the finished oil.

[0089] Olefin copolymers will generally be present, on an actives basis, at 0.1 wt. % or greater, for example at 0.1 to 12 wt. % of the lubricating oil composition. In certain embodiments, the OCP is present, on an actives basis, at 0.2 to 10 wt. %, 0.3 to 9 wt. %, 0.4 to8 wt. %, or 0.5 to 7 wt. % of the lubricating oil composition. In still further embodiments, the OCP is present, on an actives basis, at 0.5 to 12.0 wt.%, 0.5 to 5 wt. %, or 1 to 2 wt. % of the lubricating oil composition. In still further embodiments, the OCP is present, on an actives basis, at 1.0 wt. % or greater, for example at 1.0 to 12.0 wt. %, 1.0 wt. % to 5 wt. %, 1.3 wt. % to 4.5 wt. %, 1.5 wt. % to 4.0 wt. %, 2.0 to 12.0 wt.%, or 2.0 wt. % to 3.5 wt. % of the lubricating oil composition.

[0090] In certain embodiments, the olefin copolymers are copolymers based on ethylene units and units of an alpha olefin (e.g., a normal alpha olefin, an isomerized alpha olefin), such as ethylene-propylene copolymer compositions. Other alpha olefins suitable in place of propylene, or in combination with ethylene and propylene to form a terpolymer or tetrapolymer, for example, include: 1 -butene, 1 -pentene, 1 -hexene, 1 -heptene, 1 -octene, 1- nonene, 1-decene; and branched chain alpha-olefins such as 4-methyl-l -pentene, 4-methyl-l- hexene, 4-methyl pentene-l,4,4-dimethyl-l-pentene, 6-methylheptene-l, and mixtures thereof.

[0091] The present lubricating oil composition may additionally contain one or more of the other commonly used lubricating oil performance additives including antioxidants, antiwear agent, metal detergents, dispersants, friction modifiers, corrosion inhibitors, demulsifiers, viscosity modifiers, pour point depressants, foam inhibitors, and others.EXAMPLES

[0092] The following non-limiting examples are illustrative of the present invention. Brief descriptions of how the examples were prepared and the test methods used in evaluation of the inventive lubricants are provided.Ammonia Aging Protocol:

[0093] Additive components were aged with ammonia to test the impact of exposure to ammonia fuel. The aged components were formulated into a finished marine lubricant and subsequently bench-tested for performance.

[0094] During the aging process, individual lubricant additive components were mixed with gaseous ammonia (NH3) at elevated temperature (80°C) for a prolonged period. After establishing an increased nitrogen content of about 600 ppm in the sample, the additives were blended into a finished lubricant product and a series of bench tests were run. The lubricant products formulated with aged ammonia exposed additives were tested against fresh oil lubricants comprising fresh additives (i.e., not aged with ammonia).Modified Institute of Petroleum 48 (MIP-48) Test

[0095] The MIP-48 Test probes thermal and oxidative performance of a lubricant. In the thermal part of the test, nitrogen is passed through a heated oil sample for 24 hours. In the oxidative part of the test, air is passed through a heated oil sample for 24 hours. The samples are cooled and the viscosities of both samples are determined. The viscosity increase of the test oil caused by oxidation is determined and corrected for the thermal effect. The oxidationbased viscosity increase for each marine lubricating oil composition was calculated by subtracting the kinematic viscosity at 200 °C for the nitrogen-blown sample from the kinematic viscosity at 200 °C for the air-blown sample and dividing the subtraction product by the kinematic viscosity at 200 °C for the nitrogen blown sample. This is done to correct potential evaporation effects during the test, or other thermal effect, thereby focusing on the impact of oxidation. This correction may result in a negative value. Test oils which exhibit better stability against oxidation-based viscosity increase will result in a lower % absolute value.DSC Oxidation Test

[0096] The DSC test was used to evaluate thin film oxidation stability of test oils, in accordance with ASTM D-6186. Heat flow to and from test oil in a sample cup is compared against a reference cup during the test.

[0097] The Oxidation Onset Temperature is the temperature at which the oxidation of the test oil starts. The Oxidation Induction Time (OIT) is the time at which the oxidation of the test oil starts. A higher oxidation induction time indicates better performance. The oxidation reaction is exothermic as shown by the heat flow. The Oxidation Induction Time evaluates the thin film oxidation stability of the test oil.Pressure Differential Scanning Calorimetry (PDSC) Test (ASTM D-6186):

[0098] Using the PDSC Test, oxidation stability of test oils (at 180 ° C and 500 psi of oxygen pressure) can be measured by detecting the exothermic release of energy that occurs when oils succumb to auto-oxidation. The length of time required to reach auto-oxidation is a measure of oxidation resistance and is known as oxidation induction time.

[0099] During this test, a small quantity of test oil is weighed into a sample pan and placed in a test cell. The cell is heated to a specified temperature and then pressurized with oxygen. The cell is held at a regulated temperature and pressure until an exothermic reaction occurs. The extrapolated onset time is measured and reported as the oxidation induction time for the lubricating oil at the specified test temperature.Example 1

[0100] Example 1 is a marine lubricant containing the following additive package:9.0 wt.% oil concentrate of a calcium sulfurized branched phenate detergent (40 wt.% diluent oil),3.4 wt.% oil concentrate of a LOB calcium sulfonate detergent (50 wt.% diluent oil),6.6 wt.% oil concentrate of a HOB calcium sulfonate detergent (40 wt.% diluent oil),0.2 wt.% succinimide dispersant,1.5 wt.% antioxidant and foam inhibitor.This phosphorous-free package was formulated to a 40BN SAE 50 (18.5 cSt @100°C) marine cylinder lubricant using Group I base oil.

[0101] The marine lubricating oil composition of Example 1 was first run as a fresh oil and evaluated for oxidative and thermal stability using the DSC test. For comparison, the individual additive components of Example 1 were subjected to the ammonia aging protocol prior to formulation of the additive package. The lubricant was then formulated to the same parameters as the fresh oil and evaluated using DSC. The oxidation induction items (summarized in Table 2 below) demonstrate that the phosphorous-free marine formulation of Example 1 does not suffer degradation in oxidative stability due to ammonia aging.Table 2.Example 2

[0102] The lubricant of Example 2 contained the following additive package:2.7 wt.% oil concentrate of a HOB calcium hydroxybenzoate detergent derived from isomerized C20-24 olefin (30 wt.% diluent oil),0.53 wt.% oil concentrate of a MOB calcium hydroxybenzoate detergent derived from isomerized C20-24 olefin (20 wt.% diluent oil),0.5 wt.% succinimide dispersant, and foam inhibitor.This phosphorous-free package was formulated to a 12BN SAE 40 (14.0 cSt @100°C) viscosity marine trunk piston engine oil lubricant using Group II base oil.

[0103] The marine lubricating oil composition of Example 2 was first run as a fresh oil and evaluated for oxidative and thermal stability using the DSC test. For comparison, the individual additive components of Example 2 were subjected to the ammonia aging protocol prior to formulation of the additive package. The lubricant was then formulated to the same parameters as the fresh oil and evaluated using DSC. The oxidation induction items (summarized in Table 3 below) demonstrate that the phosphorous-free marine formulation of Example 2 does not suffer degradation in oxidative stability due to ammonia aging.Table 3Example 3The lubricant of example 3 contained the following additive package:2.7 wt.% oil concentrate of a HOB calcium hydroxybenzoate detergent derived from isomerized C20-24 olefin (30 wt.% diluent oil)0.53 wt.% oil concentrate of a MOB calcium hydroxybenzoate detergent derived from isomerized C20-24 olefin (20 wt.% diluent oil)0.5 wt.% succinimide dispersant foam inhibitor

[0104] This package contained 0.67 wt.% of a primary zinc dithiophosphate, contributing 485ppm of phosphorous to the formulation. This package was formulated to a 12BN SAE 40 (14.0 cSt @100°C) viscosity marine trunk piston engine oil lubricant using majority amount Group II base oil.

[0105] The marine lubricating oil composition of example 3 was first run as a fresh oil and evaluated for oxidative and thermal stability using the DSC test. In the next experiment, the individual additive components of inventive example 3 were first subjected to the ammonia aging protocol prior to formulation of the additive package. The lubricant was then formulated to the same parameters as the fresh oil and was run in the PDSC. The oxidation induction items (summarized in Table 4 below) demonstrate that the phosphorous-free marine formulation of example 3 does not suffer degradation in oxidative stability due to ammonia aging as is evident by the higher oxidation induction time after the ammonia aging protocol.Table 4Comparative Example A

[0106] The lubricant of Comparative Example A was nearly identical to Example 2. The only difference being the addition of 1.34 wt. % of a primary zinc dithiophosphate. This package contained 915 ppm phosphorous. This package was formulated to a 12BN SAE 40 (14.0 cSt @100°C) viscosity marine trunk piston engine oil lubricant using Group II base oil.

[0107] The marine lubricating oil composition of Comparative Example A was first run as a fresh oil and evaluated for oxidative and thermal stability using the PDSC and MIP- 48 tests. For comparison, the individual additive components of Comparative Example A were subjected to the ammonia aging protocol prior to formulation of the additive package. The lubricant was then formulated to the same parameters as the fresh oil and evaluated using PDSC (lower value indicates worse performance) and MIP-48 tests (higher value indicates worse performance). The test results (summarized in Table 5 below) demonstrate that the phosphorous-containing marine formulation of Comparative Example A does suffer performance degradation due to ammonia aging. This is evident by the lower oxidation induction time in the PDSC test and higher oxidation based viscosity increase of the test oils in the MIP-48 test aged with the ammonia aging protocol.Table 5

[0108] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, within a range includes every point or individual value between its end pointseven though not explicitly recited. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

[0109] Likewise, the term “comprising” is considered synonymous with the term “including.” Likewise whenever a composition, an element or a group of elements is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0110] The terms "a" and "the" as used herein are understood to encompass the plural as well as the singular.

[0111] Various terms have been defined above. To the extent a term used in a claim is not defined above, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted.

[0112] The foregoing description of the disclosure illustrates and describes the present disclosure. Additionally, the disclosure shows and describes only the preferred embodiments but, as mentioned above, it is to be understood that the disclosure is capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the concept as expressed herein, commensurate with the above teachings and / or the skill or knowledge of the relevant art. While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of thedisclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

[0113] It is understood that when combinations, subsets, groups, etc. of elements are disclosed (e.g., combinations of components in a composition, or combinations of steps in a method), that while specific reference of each of the various individual and collective combinations and permutations of these elements may not be explicitly disclosed, each is specifically contemplated and described herein.

[0114] The embodiments described hereinabove are further intended to explain best modes known of practicing it and to enable others skilled in the art to utilize the disclosure in such, or other, embodiments and with the various modifications required by the particular applications or uses. Accordingly, the description is not intended to limit it to the form disclosed herein. Also, it is intended that the appended claims be construed to include alternative embodiments.

Claims

CLAIMS1. A marine lubricating oil composition for a non-carbon based fueled marine engine, wherein the marine lubricating oil composition comprises: base oil; and total of 900 ppm or less of phosphorous from one or more phosphorous-containing compounds; wherein the marine lubricating oil composition has a TBN of 200 mg KOH / g or less; and wherein the marine lubricating oil composition meets the specification for SAE J300 revised January 2015 requirements for SAE 20, SAE 30, SAE 40, SAE 50, or SAE 60 monograde lubricating oil.

2. The marine lubricating oil composition of claim 1, wherein the base oil is Group II, III, IV, or V base oil.

3. The marine lubricating oil composition of claim 1, further comprising a calcium phenol- based detergent.

4. The marine lubricating oil composition of claim 3, wherein the calcium phenol-based detergent is a sulfurized or unsulfurized calcium phenate or calcium hydroxybenzoate detergent.

5. The marine lubricating oil composition of claim 4, wherein the calcium sulfurized or unsulfurized phenate or calcium hydroxybenzoate is derived from isomerized alpha olefins.

6. The marine lubricating oil composition of claim 1, wherein the one or more phosphorous-containing compound in zinc dithiophosphate or ashless dithiophosphate.

7. The marine lubricating oil composition of claim 1, wherein the marine lubricating oil composition is a marine system oil, marine cylinder lubricant, or trunk piston engine oil.

8. The marine lubricating oil composition of claim 1, wherein the marine lubricating oil composition is contaminated with ammonia.

9. A marine lubricating oil composition for ammonia-fueled marine engine comprising: a base oil; and a phenol-based detergent; wherein the marine lubricating oil composition comprises total of 900 ppm or less of phosphorus from one or more phosphorous-containing compounds; wherein the marine lubricating oil composition has a TBN of 200 mg KOH / g or less; and wherein the marine lubricating oil composition meets the specification for SAE J300 revised January 2015 requirements for SAE 20, SAE 30, SAE 40, SAE 50, or SAE 60 monograde lubricating oil.

10. The marine lubricating oil composition of claim 9, wherein the base oil is Group II, III, IV, or V base oil.

11. The marine lubricating oil composition of claim 9, wherein the phenol -based detergent is calcium sulfurized or unsulfurized phenate or calcium hydroxybenzoate.

12. The marine lubricating oil composition of claim 11, wherein the calcium sulfurized or unsulfurized phenate or calcium hydroxybenzoate is derived from isomerized alpha olefins.

13. The marine lubricating oil composition of claim 9, wherein the one or more phosphorous-containing compound is zinc dithiophosphate or ashless dithiophosphate.

14. The marine lubricating oil composition of claim 9, wherein the marine lubricating oil composition is a marine system oil, marine cylinder lubricant, or trunk piston engine oil.

15. The marine lubricating oil composition of claim 9, wherein the marine lubricating oil composition is contaminated with ammonia.

16. A method of lubricating a low-speed or medium-speed marine diesel engine operated using ammonia fuel, the method comprising: lubricating the low-speed or medium-speed marine diesel engine with a marine lubricating oil composition comprising: a base oil; and a phenol-based detergent; wherein the marine lubricating oil composition comprises total of 900 ppm or less of phosphorous from one or more phosphorous-containing compounds; wherein the marine lubricating oil composition has a TBN of 200 mg KOH / g or less; and wherein the marine lubricating oil composition meets the specification for SAE J30 revised January 2015 requirements for SAE 20, SAE 30, SAE 40, SAE 50, or SAE 60 monograde lubricating oil.

17. The method of claim 16, wherein the base oil is Group II, III, IV, or V base oil.

18. The method of claim 16, wherein the phenol-based detergent is calcium sulfurized or unsulfurized phenate or calcium hydroxybenzoate.

19. The method of claim 18, wherein the calcium sulfurized or unsulfurized phenate or calcium hydroxybenzoate is derived from isomerized alpha olefins.

20. The method of claim 16, wherein the one or more phosphorous-containing compound is zinc dithiophosphate or ashless dithiophosphate.

21. The method of claim 16, wherein the marine lubricating oil composition is a marine system oil, marine cylinder lubricant, or trunk piston engine oil.

22. The method of claim 16, wherein the marine lubricating oil composition is contaminated with ammonia.

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