ES2665337T3 - Additive package for marine engine lubrication - Google Patents

Abstract

A package of additives for a lubricating oil composition for two-stroke or four-stroke marine engines, comprising less than 50% by mass of an oil of lubricating viscosity; more than 50% by mass of (A) an over-alkali metal hydroxybenzoate detergent additive and (B) an over-alkalized metal sulphonate detergent additive; and (C) an oil-soluble hydrocarbylphenol-aldehyde condensate additive in an amount in the range of 1 to 10, preferably 3 to 6, mass%; wherein the ratio of (A) to (B), expressed as mmol of soap, is in the range of 90:10 to 10:90, preferably 80:20 to 20:80.

Description

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DESCRIPTION

Additive package for marine engine lubrication Field of the invention

This invention relates to the lubrication of two-stroke and four-stroke internal combustion marine diesel engines, the first commonly referred to as crosshead engines and the second tubular piston engines. The respective lubricants for these applications are commonly known as marine diesel cylinder lubricants ("MDCL's") and tubular piston engine oils ("TPEO's").

Background of the invention

Crosshead motors are slow motors with a high to very high power range. They include two separate lubricated parts: the lubricated piston / cylinder assembly, with all-loss lubrication, by a highly viscous oil (an MDCL); and the crankshaft lubricated by a less viscous lubricant, usually called system oil.

Tubular piston engines can be used in marine, power generation and rail traction applications, and have a higher speed than crosshead engines. A single lubricant (TPEO) is used for the lubrication of the crankcase and the cylinder. All major moving parts of the engine, that is, the main and connecting rod head bearings, the camshaft and the valve mechanism, are lubricated by means of a pumped circulation system. The cylinder liners are partially lubricated by immersion lubrication, and partially by the oil of the circulation systems, which finds its way to the cylinder wall through holes in the piston skirt by the connecting rod and the piston bolt .

Marine lubricants are routinely formulated with metal detergent additives. A practical problem in the use of detergents for this purpose is that certain combinations of salicylate and sulphonate detergents exhibit stability problems, evidenced by gel or phase separation.

US2005 / 137098 describes additive concentrates containing over-alkalized calcium sulphonate detergents and over-alkalized calcium salicylate detergents and lubricating oil compositions prepared with these additive concentrates.

The objective of this invention is to reduce or overcome such problems.

Compendium of the invention

It has now been found that the use of additives illustrated by alkylphenols with methylene bridges allows overcoming the above problem.

Thus, the present invention provides in one aspect a package of additives for a lubricating oil composition for two-stroke or four-stroke marine engines, comprising less than 50% by mass of an oil of lubricating viscosity; more than 50% by mass of (A) an over-alkalized metal hydroxybenzoate detergent additive and (B) an over-alkalized metal sulphonate detergent additive; and (C) an oil-soluble hydrocarbylphenol aldehyde condensate additive in an amount in the range of 1 to 10, preferably 3 to 6, mass%; wherein the ratio of (A) to (B), expressed as mmol of soap, is in the range of 90:10 to 10:90, preferably 80:20 to 20:80.

In a second aspect, a lubricating oil composition for two-stroke marine engines is provided comprising an oil of lubricating viscosity, in a larger amount, mixed with a smaller amount of the additive package defined above; wherein the composition has a TBN of 10 to 120, preferably 40 to 100, using ASTM D2896, or a four-stroke marine engine lubricating oil composition comprising an oil of lubricating viscosity, in a larger amount, mixed with an amount minor of the additive package defined above; wherein the composition has a TBN of 25 to 60, using ASTM D2896.

The additive package is preferably used at a treatment rate of 15 to 30% by mass to produce the two-stroke composition, and at a treatment rate of 10 to 20% by mass for the composition for four-stroke engine.

The lubricating oil composition preferably includes 0.15 to 1.5% by mass of the oil-soluble hydrocarbylphenol-aldehyde condensate additive for the two-stroke composition, and 0.1 to 1% by mass of the condensate additive of oil-soluble hydrocarbylphenol-aldehyde for the four-stroke engine.

In additional aspects the present invention comprises:

the use of 1 to 10% by mass of the additive (C) in a marine diesel cylinder lubricant containing the additives (A) and (B), defined above and in the above ratio, to improve the stability of the additives (A ) and (B) in the

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lubricant; Y

a method for lubricating a marine diesel crosshead engine comprising supplying a composition of the previous aspect of the invention to the engine piston / cylinder during operation.

In this specification, the following words and expressions, if and when used, have the meanings attributed below:

"Active ingredients" or "(i.a.)" refers to additive material that is not diluent or solvent;

"Comprising", or any similar word, specifies the presence of indicated features, stages or integers or components, but does not exclude the presence or addition of one or more other features, stages, integers, components or groups thereof; the terms "consists of" or "consists essentially of" or similar words may be encompassed within "comprises" or similar words, wherein "consists essentially of" allows the inclusion of substances that do not materially affect the characteristics of the composition a the one that applies;

"Hydrocarbyl" means a substituent or group (such as an alkyl group) having a carbon atom attached directly to the rest of a molecule and a predominantly hydrocarbon character. Heteroatoms may be present, provided they do not alter the essentially hydrocarbon nature of the group.

"Greater amount" means 40 or even 50% by mass or more of a composition, preferably 60% by mass or more, even more preferably 70% by mass or more, and most preferably 80% by mass or more;

"Minor amount" means less than 50% by mass of a composition, preferably less than 40% by mass, even more preferably less than 30% by mass, most preferably less than 20% by mass, and most preferably less than 10 % by mass;

"TBN" means total base number, measured by ASTM D2896.

In addition, in this specification, if and when they are used:

"Calcium content" is as measured by ASTM 4951;

"Phosphorus content" is as measured by ASTM D5185;

"Sulfated ash content" is as measured by ASTM D874;

"Sulfur content" is as measured by ASTM D2622;

"KV100" means kinematic viscosity at 100 ° C, measured by ASTM D445.

Also, it will be understood that the various components used, essential as well as optimal and customary, may react under conditions of formulation, storage or use, and that the invention also provides the product obtainable or obtained as a result of any such reaction.

Furthermore, it is understood that any upper and lower limits of amounts, ranges and ratios set forth herein may be combined independently.

Detailed description of the invention

The features of the invention will now be discussed in more detail below.

Lubricating viscosity oil

The lubricating composition contains a greater proportion of an oil of lubricating viscosity. Such lubricating oils may vary in viscosity from mineral oils of light distillates to heavy lubricating oils. In general, the viscosity of the oil ranges from 2 to 40, such as 3 to 15, mm2 / s, measured at 100 ° C, and has a viscosity index of 80 to 100, such as 90 to 95. The lubricating oil It may comprise more than 60, typically more than 70,% by mass of the composition.

Natural oils include animal oils and vegetable oils (eg, castor oil, pork fat oil); liquid petroleum oils and hydrorefined mineral oils, treated with solvents or treated with acids of the paraffinic, naphthenic and paraffinic-naphthenic mixed types. Oils of lubricating viscosity derived from coal or shale also serve as useful base oils.

Synthetic lubricating oils include hydrocarbon oils and halogen-substituted hydrocarbon oils, such as polymerized and interpolymerized olefins (e.g., polybutylenes, polypropylenes, propylene-isobutylene copolymers, chlorinated polybutylenes, poly (1-hexenes), poly (1-) octenos), poly (1-decene)); alkylbenzenes (eg, dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di (2-ethylhexyl) benzenes); polyphenyls (eg, biphenyls,

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terphenyls, alkylated polyphenols); and alkylated diphenyl ethers and alkylated diphenyl sulphides and derivatives, analogs and homologs thereof.

The polymers and interpolymers of alkylene oxides and derivatives thereof where the terminal hydroxyl groups have been modified by esterification, etherification, etc., constitute another class of known synthetic lubricating oils. These are illustrated by polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide, and the alkyl and aryl ethers of polyoxyalkylene polymers (e.g., methyl polyisopropylene glycol ether having a molecular weight of 1,000, or polyethylene glycol diphenyl ether having a molecular weight of 1,000 to 1,500); and mono- and polycarboxylic esters thereof, for example, acetic acid esters, mixed C3-C8 fatty acid esters and C13 oxoacid diester of tetraethylene glycol.

Another suitable class of synthetic lubricating oils comprises esters of dicarboxylic acids (eg, phthalic acid, succinic acid, alkylsuccinic acids and alkenyl succinic acids, maleic acid, azelaic acid, subic acid, sebacic acid, fumaric acid, adipic acid, dimer of linoleic acid, malonic acid, alkylmalonic acids, alkenylmalonic acids) with various alcohols (eg, butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol). Specific examples of such esters include dibutyl adipate, di (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisoctyl azelate, diunchyl azelate, dioctyl phthalate, dieicosyl sebacate, diester 2 -ethylhexyl linoleic acid dimer, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid.

Esters useful as synthetic oils also include those prepared from C5 to C12 monocarboxylic acids and polyols and esters of polyols such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol and tripentaerythritol.

Silicon-based oils such as polyalkyl-, polyaryl-, polyalkoxy- or polyaryloxysilicone oils and silicate oils comprise another useful class of synthetic lubricants; such oils include tetraethyl silicate, tetraisopropyl silicate, tetra- (2-ethylhexyl) silicate, tetra- (4-methyl-2-ethylhexyl) silicate, tetra- (p-tert-butyl-phenyl) silicate, hexa - (4-methyl-2-ethylhexyl) disiloxane, poly (methyl) siloxanes and poly (methylphenyl) siloxanes. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (eg, tricresyl phosphate, trioctyl phosphate, diethyl ester of decylphosphonic acid) and polymeric tetrahydrofurans.

Unrefined, refined and re-refined oils can be used in the lubricants of the present invention. Unrefined oils are those obtained directly from a natural or synthetic source without further purification treatment. For example, a shale oil obtained directly from retort distillation operations; petroleum oil obtained directly from distillation; or ester oil obtained directly from esterification and used without further treatment are unrefined oils.

The publication of the American Petroleum Institute (API) "Engine Oil Licensing and Certification System", Industry Services Department, fourteenth edition, December 1996, Annex 1, December 1998, lists base oils as follows:

a) Group I base oils, contain less than 90 percent saturated and / or more than 0.03 percent sulfur, and have a viscosity index greater than or equal to 80 and less than 120 using the test methods specified in Table E-1.

b) Group II base oils, contain more than or equal to 90 percent saturated and less than or equal to 0.03 percent sulfur, and have a viscosity index greater than or equal to 80 and less than 120 using the test methods specified in Table E-1.

c) Group III base oils, contain more than or equal to 90 percent saturated and less than or equal to 0.03 percent sulfur, and have a viscosity index greater than or equal to 120 using the test methods specified in Table E-1.

d) Group IV base oils are polyalphaolefins (PAO).

e) Group V base oils, include all other base oils not included in Group I, II, III or IV.

The analytical methods for the base oil are tabulated below:

Table E-1

 PROPERTY

 TESTING METHOD

 Saturated

 ASTM D 2007

 Viscosity index

 ASTM D 2270

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 Sulfur

 ASTM D 2622

 ASTM D 4294

 ASTM D 4927

 ASTM D 3120

The present invention preferably encompasses those of the above oils containing more than or equal to 90% saturated and less than or equal to 0.03% sulfur as an oil of lubricating viscosity, eg, Group II, III, IV or V. They also include base oils derived from hydrocarbons synthesized by the Fischer-Tropsch process. In the Fischer-Tropsch process, synthesis gas is first generated, which contains carbon monoxide and hydrogen (or "singles"), and then converted into hydrocarbons using a Fischer-Tropsch catalyst. These hydrocarbons typically require additional processing in order to be useful as a base oil. For example, they may be, by methods known in the art, hydroisomerized; hydrocracked and hydroisomerized; descended; or hydroisomerized and lowered. The singas can be prepared, for example, from gas such as natural gas or other gaseous hydrocarbons by steam reforming, wherein the base oil may be referred to as gas-to-liquid base oil ("GTL"); or from biomass gasification, where the base oil can be referred to as a base oil to liquid biomass ("BTL" or "BMTL"); or from coal gasification, where the base oil may be referred to as coal-to-liquid base oil ("CTL"). The invention, however, is not limited to the use of the aforementioned base oils; therefore, it can include, for example, the use of Group I base oils and refined heavy oil.

Preferably, the lubricating viscosity oil in this invention contains 50% by mass or more of said base oils. It may contain 60, such as 70, 80 or 90% by mass or more of said base oil or a mixture thereof. The lubricating viscosity oil may be substantially all of said base oil or a mixture thereof.

Additives (A) and (B)

Each of these is a detergent, which is an additive that reduces the formation of deposits, for example, deposits of varnish and lacquer at high temperature, in engines; It has neutralizing properties of acids and is capable of keeping finely divided solids in suspension. It is based on metallic "soaps," that is, metal salts of acidic organic compounds, sometimes referred to as surfactants.

A detergent comprises a polar head with a long hydrophobic tail. Large amounts of a metal base are included by reacting an excess of a metal compound, such as an oxide or hydroxide, with an acid gas such as carbon dioxide to give an over-alkalized detergent comprising neutralized detergent as the outer layer of a base micelle metallic (eg carbonate).

The detergent is preferably an alkali metal or alkaline earth metal additive such as a calcium salt, magnesium, sodium or barium salt soluble in oil or dispersible in super-alkalized oil of a surfactant selected from an acid, wherein the super-alkalization is provided by an insoluble salt in metal oil, eg, carbonate, basic carbonate, acetate, formate, hydroxide or oxalate, which is stabilized in an oil diluent by the oil-soluble salt of the surfactant. The metal of the oil-soluble surfactant salt may be the same or different from the metal of the oil-insoluble salt. Preferably the metal, whether the metal of the oil soluble or oil insoluble salt, is calcium.

The TBN of the detergent may be low, that is, less than 50 mg KOH / g, medium, that is, 50-150 mg KOH / g, or high, that is, above 150 mg KOH / g, determined by ASTM D2896. Preferably the TBN is medium or high, that is, more than 50 TBN. More preferably, the TBN is at least 60, more preferably at least 100, more preferably at least 150, and up to 500, such as up to 350 mg KOH / g, determined by ASTM D2896.

In the detergent (A), the surfactant is selected from a hydroxybenzoic acid, a particular example being salicylic acid, and wherein the salt is a salicylate. Salicylate detergents are well known in the art.

In the detergent (B), the surfactant is selected from a sulfonic acid, wherein the salt is a sulphonate. Sulphonate detergents are also well known in the art.

The detergents that can be used are those which are substituted with hydrocarbyl (such as alkyl), such as those known in the art.

As indicated above, the ratio of (A) to (B), expressed as mmol of soap, is in the range of 90:10 to 10:90. As examples of the upper limit of the interval, 80:20 and 75:25 can be mentioned. As an example of the lower limit of the interval, 25:75 can be mentioned. These upper and lower limits can be combined independently to provide subintervals.

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Additive (C): eg alkylphenols with methylene bridges (“MBAP's”)

These are known in the art, and can comprise an oil-soluble mixture of oxyalkylated hydrocarbylphenol condensates wherein the oxyalkyl groups prepared from phenolic functional groups have the formula - (R'O) n -where R 'is an ethylene group , propylene or butylene; and n is independently from 0 to 10; less than 45, preferably less than 30, mol% of the phenolic functional groups of the condensates are non-oxyalkylated; and more than 55 mol% of the phenolic functional groups of the condensates are mono-alkylated.

Such condensates can be represented by the following general structural formula:

image 1

where:

x is 1 to 50, preferably 1 to 40, more preferably 1 to 30;

R1 and R2 are H, hydrocarbyl groups having 1 to 12 carbon atoms, or hydrocarbyl groups having 1 to 12 carbon atoms and at least one heteroatom; Y

R is a hydrocarbyl group having 9 to 100, preferably 9 to 70, most preferably, 9 to 50, carbon atoms.

EP-A-2 374 866 describes such condensates in more detail. MBAPs constitute an embodiment of them.

As indicated above, (C) is present in an amount in the range of 1 to 10, preferably 3 to 5,% by mass. As examples of subintervals, 1 to 7 and 1 to 5% by mass can also be mentioned.

For the avoidance of doubt, it is indicated that an MBAP used in this invention may be plugged terminally or not plugged terminally.

Marine lubricants

Marine Diesel Cylinder Lubricant ("MDCL")

An MDCL may employ 10-35, preferably 13-30, most preferably 16-24, mass% of a concentrate or additive package, the remainder being base oil. Preferably it includes at least 50, more preferably at least 60, even more preferably at least 70,% by mass of oil of lubricating viscosity based on the total mass of MDCL. Preferably, the MDCL has a compositional TBN (using ASTM D2896) of 10-100, such as 70-100 or 40-100, preferably 60-90, more preferably 70-80.

The following may be mentioned as examples of typical proportions of additives in an MDCL.

 Additive

 Mass% of i.a. (Broad)% by mass of i.a. (Favorite)

 detergent (s)

 1-20 3-15

 dispersant (s)

 0.5-5 1-3

 antiwear agent (s)

 0.1-1.5 0.5-1.3

 spill point dispersant

 0.03-1.15 0.05-0.1

 base oil

 rest rest

Tubular piston engine oil ("TPEO")

A TPEO may employ 7-35, preferably 10-28, more preferably 12-24, mass% of a concentrate or additive package, the remainder being base oil. Preferably, the TPEO has a compositional TBN (using 5 D2896) of 25-60, such as 25-55.

The following may be mentioned as typical proportions of additives in a TPEO.

 Additive

 Mass% of i.a. (Broad)% by mass of i.a. (Favorite)

 detergent (s)

 0.5-12 2-8

 dispersant (s)

 0.5-5 1-3

 antiwear agent (s)

 0.1-1.5 0.5-1.3

 oxidation inhibitor

 0.2-2 0.5-1.5

 corrosion inhibitor

 0.03-0.15 0.05-0.1

 spill point dispersant

 0.03-1.15 0.05-0.1

 base oil

 rest rest

The terms "oil soluble" or "oil dispersible", as used herein, do not necessarily indicate that the compounds or additives are soluble, dissolvable, miscible or capable of being suspended in the oil in all proportions. These do mean, however, that they are, for example, stably soluble or dispersible in oil to a sufficient extent to exert their intended effect in the environment in which the oil is used. In addition, the additional incorporation of other additives may also allow the incorporation of higher levels of a particular additive, if desired.

The lubricating compositions of this invention comprise defined (ie, independent) individual components, which may or may not remain chemically the same before and after mixing.

It may be desirable, although not essential, to prepare one or more packages of additives or concentrates comprising the additives, whereby the additives can be added simultaneously to the oil of lubricating viscosity to form the lubricating oil composition. The dissolution of the additive package (s) in the lubricating oil can be facilitated by solvents and by mixing, accompanied by gentle heating, but this is not essential. The additive package (s) will typically be formulated to contain the additive (s) in appropriate amounts to provide the desired concentration, and / or to perform the intended function in the final formulation when the ( The package (s) are / are combined with a predetermined amount of base lubricant.

Thus, the additives may be mixed with small amounts of base oil or other compatible solvents, together with other desirable additives to form additive packages containing the active ingredients in an amount, based on the additive package, of, for example, from 2.5 to 90, preferably from 5 to 75, most preferably from 8 to 60,% by mass of additives in the appropriate proportions, the rest being base oil.

The final formulations may typically contain about 5 to 40% by mass of the additive package (s), the remainder being base oil.

Examples

The present invention is illustrated by, but not limited to, the following examples.

Stability Test Method

A calcium salicylate detergent (basicity index 1.35) and a calcium sulphonate detergent (basicity index 22.0) were mixed in various proportions in a single stage, aided by stirrers and hot plates, at 75 ° C for 30 minutes with 1% diluent oil. This provided a set of mixtures.

Each resulting mixture was poured into graduated glass stability tubes, and tested for a period of 12 weeks at room temperature and at 60 ° C.

The stability tubes were visually inspected weekly for, as evidence of the

additive instability, gel formation, phase separation, amount of sediment that fell to the bottom of the tube, and turbidity.

The test was carried out on mixtures containing methylene bridge dodecylphenoxyethanol (an "MBAP" not capped end-to-end) and on mixtures that did not contain it.

5 Results

 RATIO (mmol / mmol): SALICILATO / SULFONATO

 MBAP (mass%)

 90/10 75/25 50/50 25/75

 0

 OK 12 gel / sep. phasesn 3 gel 1 gel> 3

 OK 12 gel / sep. phasesn 2 gel 1 gel 3

 one

 OK 12 OK 12 gel 1 gel> 3

 OK 12 gel / sep. phasesn 5 gel 1 gel 2

 3

 OK 12 OK 12 gel / sep. phasesn 3 gel> 3

 OK 12 gel / sep. phasesn 7 gel / sep. phasesn 6 gel> 3

 5

 OK 12 OK 12 OK 12 OK 12

 OK 12 OK 12 OK 12 OK 12

Key:

okay

gel / sep. 10 numbers phases

no stability problems of the additive were observed

additive instability (gel formation more severe than phase separation)

number of weeks in which the stability behavior was observed and reported (first

number, test at room temperature; second number, test at 60 ° C)

The above data shows that:

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1. at a 90/10 ratio, no stability problems were observed, even in the absence of MBAP.

2. at a 75/25 ratio, problems were observed in the absence of MBAP; the tests at room temperature indicated that there were no stability problems at 1, 3 and 5% by mass of MBAP; the tests at 60 ° C indicated an improvement at 1 and 3% by mass of MBAP and no problem at 5% by mass of MBAP.

3. at a 50/50 ratio, problems were observed in the absence of MBAP and 1% by mass of MBAP; the 3% mass trials of MBAP resulted in some improvement; the 5% mass tests of MBAP indicated that there were no stability problems both at room temperature and at 60 ° C.

4. at a 25/75 ratio, problems were observed without MBAP; the results at room temperature at 1 and 3% by mass of MBAP being worse than the results at 60 ° C; the 5% mass tests of MBAP indicated that there were no stability problems both at room temperature and at 60 ° C.

Claims (9)

5 10 fifteen twenty 25 30 1. A package of additives for a lubricating oil composition for two-stroke or four-stroke marine engines, comprising less than 50% by mass of an oil of lubricating viscosity; more than 50% by mass of (A) an over-alkalized metal hydroxybenzoate detergent additive and (B) an over-alkalized metal sulphonate detergent additive; and (C) an oil-soluble hydrocarbylphenol aldehyde condensate additive in an amount in the range of 1 to 10, preferably 3 to 6, mass%; wherein the ratio of (A) to (B), expressed as mmol of soap, is in the range of 90:10 to 10:90, preferably 80:20 to 20:80. 2. A lubricating oil composition for two-stroke marine engines, comprising an oil of lubricating viscosity in a larger amount, and mixed with a smaller amount of the additive package claimed in claim 1; wherein the composition has a TBN of 10 to 120, preferably 40 to 100, using ASTM D2896. 3. A lubricating oil composition for four-stroke marine engines, comprising an oil of lubricating viscosity in a larger amount, and mixed with a smaller amount of the additive package claimed in claim 1; wherein the composition has a TBN of 25 to 60, using ASTM D2896. 4. The additive package or composition of claims 1,2 or 3, wherein (A) is an over-alkalized calcium salicylate detergent. 5. The additive package or composition of any one of the preceding claims, wherein (B) is an over-alkalized calcium sulphonate detergent. 6. The additive package or composition of any one of the preceding claims, wherein (C) is a methylene bridge alkylphenol, whose hydroxyl groups are terminally plugged or not capped. 7. The composition of any one of claims 2 to 6, in the form of a lubricant for marine diesel cylinders. 8. The use of 1 to 10% by mass of the additive (C), defined in claim 1 or claim 6, in a package of additives for a marine diesel lubricant containing the additives (A) and (B), defined in claim 1 and in the relationship of claim 1, to improve the stability of the additives (A) and (B) in the lubricant, measured by gel formation, phase separation, sediment or turbidity by visual inspection over a period 12 weeks at room temperature and 60 ° C. 9. A method for lubricating a marine crosshead diesel engine, which comprises supplying a composition of any of claims 2 to 7 to the engine piston / cylinder during operation.