EP2304006B1 - Cylinder lubricant for a two-stroke marine engine - Google Patents

Description

Field

The present invention relates to a two-cycle marine engine cylinder lubricant for use with both high sulfur and low sulfur fuel oils. It relates more particularly to a lubricant having sufficient neutralization capacity vis-à-vis the sulfuric acid formed during the combustion of high-sulfur fuel oil, while limiting the formation of deposits during the use of fuel oils. low sulfur content.

Technological Background of the Invention

The document FR2094182 discloses lubricants containing an anti-rust and anti-corrosion additive based on polyalkoxylated compounds, including a C18 amine. The amount of amine used is very small. It is further indicated that carbonate is the compound used to provide the basicity of the lubricant.

The marine oils used in slow-moving 2-stroke engines are of two types. The cylinder oils on the one hand, ensuring the lubrication of the cylinder piston assembly, and the system oils on the other hand, ensuring the lubrication of all moving parts out of the cylinder piston assembly. Within the cylinder piston assembly, the combustion residues containing acid gases are in contact with the lubricating oil.

Acid gases are formed from the combustion of fuel oils; they are in particular sulfur oxides (SO ₂ , SO ₃ ), which are then hydrolysed when in contact with the moisture present in the combustion gases and / or in the oil. This hydrolysis generates sulfurous acid (HSO ₃ ) or sulfuric acid (H ₂ SO ₄ ).

To preserve the surface of the liners and avoid excessive corrosive wear, these acids must be neutralized, which is usually done by reaction with the basic sites included in the lubricant.

The capacity of neutralization of an oil is measured by its BN or Base Number in English, characterizing its basicity. It is measured according to ASTM D-2896 and is expressed in equivalent weight of potash per gram of oil or mg of KOH / g. The BN is a standard criterion for adjusting the basicity of cylinder oils to the sulfur content of the fuel used, in order to neutralize all the sulfur contained in the fuel, and likely to be converted into sulfuric acid by combustion and hydrolysis.

Thus, the higher the sulfur content of a fuel oil, the higher the BN of a marine oil. This is why there are marine oils on the market. BN ranging from 5 to 100 mg KOH / g. This basicity is provided by detergents which are overbased by insoluble metal salts, especially metal carbonates. The detergents, mainly of the anionic type, are, for example, metal salicylate, phenate, sulphonate or carboxylate soaps which form micelles in which the insoluble metal salt particles are kept in suspension. The usual overbased detergents intrinsically have a BN conventionally between 150 and 700 mg KOH per gram of detergent. Their mass percentage is fixed in the lubricant as a function of the level of BN that one wishes to achieve.

A part of the BN can also be provided by non-overbased or "neutral" detergents with a NO 2 typically of less than 150. However, it is not conceivable to make cylinder lubricant formulations for a marine engine where all the BN is supplied by "neutral" detergents: they should indeed be incorporated in too large quantities, which could deteriorate other properties of the lubricant and would not be realistic from an economic point of view.

The insoluble metal salts of the overbased detergents, for example calcium carbonate, thus contribute significantly to the BN of the usual lubricants. It can be considered that at least 50%, typically 75%, of the BN of the cylinder lubricants is thus provided by these insoluble salts.

The detergent part itself, or metal soaps, found in both neutral and overbased detergents typically provides the bulk of the BN complement.

Environmental concerns have led in some areas, including coastal areas, to limit the sulfur content in fuel oils used on ships.

For example, MARPOL Annex 6 (Regulations for the Prevention of air pollution from ships) of the IMO (International Maritime Organization) entered into force in May 2005. It sets a maximum sulfur content of 4.5% m / m of fuel oils. and the creation of Sulfur Oxide Controlled Emission Zones (SOx Emission Control Areas). Vessels entering these areas must use fuel with a maximum sulfur content of 1.5% m / m or other alternative treatment to limit SOx emissions to meet the specified values. The notation% m / m denotes the weight percentage of a compound relative to the total weight of fuel oil or lubricating composition in which it is included.

More recently, the Marine Environment Protection Committee (MEPC) met in April 2008 and approved proposals for amendments to MARPOL Annex 6. These proposals are summarized in the table below. They present a scenario in which the content restrictions Sulfur maximum are becoming more stringent with a maximum global limit of 4.5% m / m to 3.5% m / m by 2012. Sulfur Emission Control Areas (SECAs) will become ECAs (Emission Control Areas) with a further reduction of the content maximum permissible sulfur from 1.5% m / m to 1.0% m / m from 2010 and the addition of new limits for NOx and particulate matter. Current Regulations MARPOL Annex 6 Maximum sulfur content General limit 4.50% m / m Limit for SECA's 1.50% m / m Amendments to MARPOL Annex 6 (MEPC Meeting No. 57 - April 2008) General limit Limit for ECA's Maximum sulfur content 3.5% m / m at 1/01/2012 1% m / m at 1/03/2010 0.5% m / m at 1/01/2020 0.1% m / m at 1/01/2015

Ships operating on trans-continental routes already use several types of heavy fuel oil according to local environmental constraints while allowing them to optimize their operating costs. This situation will continue irrespective of the final level of the maximum permissible sulfur content in fuel oils.

Thus most of the container ships currently under construction provide for the implementation of several bunkers, for a high sulfur 'high seas' oil on the one hand and for a 'SECA' fuel with lower sulfur content or equal to 1.5% m / m on the other hand.

The switching between these two categories of fuel oil may require adaptation of the operating conditions of the engine, in particular the use of appropriate cylinder lubricants.

Currently, in the presence of high sulfur fuel oil (3.5% m / m and above), marine lubricants with a BN of about 70 are used.

In the presence of a fuel with a low sulfur content (1.5% m / m and less), marine lubricants with a BN of about 40 are used (this value will in the future be reduced).

In these two cases, then a sufficient neutralization capacity is reached because the concentration required in basic sites provided by the overbased detergents of the Marine lubricant is reached, but it is necessary to change lubricant at each change of fuel type.

In addition, each of these lubricants has limitations of use resulting from the following observations: the use of a BN 70 cylinder lubricant in the presence of a low sulfur fuel oil (1.5% w / w and less) and at fixed lubrication rate, creates a large excess of basic sites (strong BN) and a risk of destabilization of micelles of unused overbased detergents, which contain insoluble metal salts. This destabilization results in the formation of insoluble metal salt deposits and having a high hardness (for example calcium carbonate), mainly on the piston ring, and eventually can lead to a risk of excessive wear polishing shirt.

As a result, the optimization of the cylinder lubrication of a slow 2-stroke engine then requires the selection of the lubricant with the BN adapted to the fuel oil and to the operating conditions of the engine. This optimization reduces the operating flexibility of the engine and requires a high degree of technical skill of the crew in defining the conditions under which the changeover from one type of lubricant to the other must be achieved.

In order to simplify the maneuvers, it would therefore be desirable to have a single cylinder lubricant for a two-stroke marine engine that can be used both with high sulfur content fuel oils and with low sulfur fuel oils.

In particular, there is a need for formulations in which BN is provided in an alternative manner to overbased detergents by compounds which do not give rise to metal deposits when they are present in excess relative to the amount of sulfuric acid at neutralize.

Description of the invention

The object of the present invention is to provide a lubricating oil that can ensure good lubrication of the marine engine cylinder and can withstand the stresses of high sulfur fuel oils and the stresses of low sulfur fuel oils.

The present invention relates to lubricating formulations having a BN sufficiently high to effectively neutralize the sulfuric acid formed in the use of high sulfur fuel oils, a significant portion of said BN being provided by oil soluble species. do not give rise to metal deposits when they are partially consumed, when using low-sulfur fuel oil.

• une ou plusieurs huiles de base lubrifiantes pour moteur marin,
• au moins un détergent à base de métaux alcalins ou alcalino terreux, surbasé par des sels métalliques de carbonate, en combinaison éventuelle avec un ou plusieurs détergents neutres,
• une ou plusieurs amines grasses solubles dans l'huile ayant un BN déterminé selon la norme ASTM D-2896 compris entre 150 et 600 milligrammes de potasse par gramme, préférentiellement compris entre 200 et 500 milligrammes de potasse par gramme,

le pourcentage massique d'amines grasses par rapport au poids total de lubrifiant étant choisi de manière à ce que le BN apporté par ces composés représente une contribution d'au moins 10 milligrammes de potasse par gramme de lubrifiant, de préférence au moins 20 milligrammes de potasse par gramme, de préférence encore au moins 30 milligrammes de potasse par gramme, encore plus préférentiellement au moins 40 milligrammes de potasse par gramme de lubrifiant, au BN total dudit lubrifiant cylindre et,
le pourcentage massique de détergents surbasés par rapport au poids total de lubrifiant étant choisi de manière à ce que le BN apporté par les sels métalliques de carbonate représente une contribution d'au plus 20 milligrammes de potasse par gramme de lubrifiant au BN total dudit lubrifiant cylindre,
l'amine grasse comportant au moins une chaîne aliphatique constituée d'au moins 16 atomes de carbone.The present invention therefore relates to cylinder lubricants having a BN determined according to ASTM D-2896 greater than or equal to 15, preferably greater than 20, preferably greater than 30, advantageously greater than 40 milligrams of potash per gram of lubricant, comprising :

• one or more lubricating base oils for a marine engine,
• at least one detergent based on alkali or alkaline earth metals, overbased with metal carbonate salts, optionally in combination with one or more neutral detergents,
• one or more oil-soluble fatty amines having a BN determined according to the ASTM D-2896 standard of between 150 and 600 milligrams of potash per gram, preferably between 200 and 500 milligrams of potash per gram,

the weight percentage of fatty amines relative to the total weight of lubricant being chosen so that the BN supplied by these compounds represents a contribution of at least 10 milligrams of potash per gram of lubricant, preferably at least 20 milligrams of potash per gram, more preferably at least 30 milligrams of potash per gram, still more preferably at least 40 milligrams of potash per gram of lubricant, to the total BN of said cylinder lubricant and,
the weight percentage of overbased detergents relative to the total weight of lubricant being chosen so that the BN supplied by the carbonate metal salts represents a contribution of at most 20 milligrams of potash per gram of lubricant to the total BN of said lubricant cylinder ,
the fatty amine comprising at least one aliphatic chain consisting of at least 16 carbon atoms.

The Applicant has found that it is possible to formulate cylinder lubricants where a significant part of BN is provided by oil-soluble fatty amines, while maintaining the level of performance compared to conventional equivalent BN formulations.

The performance in question here is in particular the ability to neutralize sulfuric acid, measured using the enthalpy test described in the examples below.

However, it is not possible to completely eliminate the BN input by the insoluble metallic particles of the overbased detergents: they constitute the "ultimate reserve" of essential basicity when operating with high-sulfur fuel oils (eg example greater than 3% m / m, or 3.5% m / m).

These insoluble metal salts also have a favorable antiwear effect provided that they are kept dispersed in the lubricant in the form of stable micelles.

In addition, it has been found that an incorporation of amine with a high content induces a significant drop in the viscosity of the lubricant, which is hardly compatible with use as a cylinder lubricant. This would also have an adverse effect on the toxicity of said lubricants.

The Applicant has also found, surprisingly, that in the presence of a significant contribution of BN by said fatty amines, an excessively high intake (greater than 20 mg of potassium hydroxide / gram of lubricant), BN by insoluble metal salts. overbased detergents (typically metalcarbonates) had an adverse effect on the ability of the cylinder lubricants to neutralize.

However, in conventional BN 40 cylinder lubricants, formulated for use with low sulfur fuel oils, the BN supplied by the insoluble metal salts is typically of the order of 30 mg of potash per gram of lubricant.

Thanks to the alternative BN provided by the fatty amines, which do not form hard metal deposits leading to wear of the parts, in combination with overbased and possibly neutral detergents, the cylinder lubricants according to the present invention are suitable both for the high fuel oils. sulfur content and for low sulfur fuels.

In one embodiment of the invention, the alternative BN provided by the oil-soluble fatty amines represents at least 15% preferably at least 30%, preferably at least 50% of the BN of said cylinder lubricant. Or, especially for BN formulas of the order of 55, the BN supplied by the oil-soluble fatty amines represents at least 55%, or at least 60%, or at least 70% of the BN of said lubricant cylinder .

Preferably, the present invention provides a cylinder lubricant having a BN determined according to the ASTM D-2896 standard of between 40 and 80 milligrams of potash per gram of lubricant, preferably between 65 and 75, or even more preferably equal to 70 milligrams of potash. per gram of lubricant.

According to another embodiment, the BN of the lubricants according to the present invention, determined according to the ASTM D-2896 standard, is between 45 and 60 milligrams of potash per gram of lubricant, preferably between 45 and 55, or even more preferably equal to 50 milligrams of potash per gram of lubricant.

According to another embodiment, the BN of the lubricants according to the present invention, determined according to the ASTM D-2896 standard, is between 54 and 60 milligrams of potash per gram of lubricant, preferably equal to 57, or even more preferably equal to 55 milligrams of potash per gram of lubricant.

According to another embodiment, the BN of the lubricants according to the present invention, determined according to ASTM D-2896, is between 40 and 50 milligrams of potash per gram of lubricant, preferably equal to 45 milligrams of potash per gram of lubricant. .

According to one embodiment, for reasons of cost and availability, the oil-soluble fatty amine (s) is (are) obtained from palm, olive, peanut, conventional or oleic rapeseed oil, of conventional or oleic sunflower, soya, cotton, from beef tallow, or palmitic, stearic, oleic, linoleic acid.

According to one embodiment, the fatty amines are chosen from amines obtained from fatty acids comprising between 16 and 18 carbon atoms.

In order to avoid the gellation phenomenon sometimes observed with a high mass content of fatty amines in the lubricant, it will be preferred to work with fatty amines containing between 16 and 22 carbon atoms.

According to one embodiment, the fatty amines are mono or polyamines, preferentially diamines.

In a preferred embodiment, they are polyamines corresponding to the general formula R- [NH (CH ₂ ) ₃ ] _n -NH ₂ , where n is an integer between 1 and 3, and R represents the fatty chain of fatty acids. saturated or unsaturated compounds containing at least 16 carbon atoms, preferably the fatty chain of oleic acid.

Particularly preferred diamines of the general formula R-NH (CH ₂ ) ₃ NH ₂ , wherein R represents the fatty chain of saturated or unsaturated fatty acids having at least 16 carbon atoms, preferably the fatty chain of the oleic acid.

The application as filed discloses fatty amine derivatives according to the present invention which are for example the amine derivatives described above. These derivatives are, for example, chosen from ethoxylated amines having from 1 to 5 ethylene oxide units and oxyamines.

In the lubricants according to the present invention, the overbased and / or neutral detergents are preferably chosen from carboxylates, sulphonates, salicylates, naphthenates, phenates, and mixed detergents combining at least two of these types of detergents.

Preferentially, these are compounds based on metals selected from the group consisting of calcium, magnesium, sodium or barium, preferably calcium or magnesium.

They are overbased by insoluble metal salts selected from the group of alkali and alkaline earth metal carbonates, preferentially calcium carbonate.

These detergents provide the complement of BN not provided by oil-soluble fatty amines in the cylinder lubricants according to the invention.

According to a preferred embodiment, the weight percentage of overbased detergents relative to the total weight of lubricant is chosen so that the BN supplied by the carbonate metal salts represents a contribution of at least 5 milligrams of potash per gram of lubricant, preferably at least 10 milligrams of potash per gram of lubricant to the total BN of said lubricant cylinder.

According to a particularly preferred embodiment, the weight percentage of overbased detergents, and possibly neutral, relative to the total weight of lubricant, is chosen so that the organic BN, provided by the detergent metal soaps, represents a contribution of at least 5. milligrams of potash per gram of lubricant, preferably at least 10 milligrams of potash per gram of lubricant, in the cylinder lubricants according to the present invention.

Preferably, the lubricant according to the invention comprises from 50 to 90% by weight of base oil, from 4 to 30% by weight of at least one detergent based on alkaline or alkaline earth metals, overbased with metal salts of carbonate, optionally in combination with one or more neutral detergents, and from 2 to 40% by weight, one or more fatty amines as described above.

The lubricants according to the invention may contain one or more functional additives chosen from dispersant additives, anti-wear additives, anti-foam additives, anti-oxidant and / or anti-rust additives.

For example, they may contain from 0.01% to 6%, preferably from 0.1% to 4% by weight of one or more antiwear additives.

They may also contain from 0.1% to 4%, preferably from 0.4% to 2% by weight of a dispersing additive.

The cylinder lubricants according to the invention preferentially have a kinematic viscosity at 100 ° C. of between 12.5 and 26.1 cSt (SAE 40, 50, 60 grades), preferably between 16.3 and 21.9 cSt (grade SAE 50).

According to a particularly preferred embodiment, the cylinder lubricants according to the invention have a kinematic viscosity at 100 ° C. of between 18 and 21.5 cSt, preferably between 19 and 21.5 cSt.

Preferably, the cylinder lubricants according to the invention comprise from 60% to 90% relative to the total weight of lubricant a mixture of one or more base oils, belonging to Groups 1 to 5 defined according to the nomenclature of API, preferentially Groups 1 or 2 according to this same nomenclature.

This mixture of base oils may contain from 10 to 25% by weight, based on the total weight of lubricant, of a BSS type I group base oil (distillation residue, kinematic viscosity at 100 ° C. of 30 mm ² / s, typically between 28 and 32 mm ² / s, and of density at 15 ° C between 895 and 915 kg / m3), and from 50 to 70% by weight, relative to the total weight lubricant, a Neutral Solvent group I base oil (distillate, density at 15 ° C between 880 and 900 kg / m3, kinematic viscosity at 100 ° C close to 11 mm ² / s for the 500 NS, or close to 12 mm ² / s for the 600NS).

According to another embodiment, in the cylinder lubricants according to the invention, the base oil or oils are partially or totally substituted with one or more thickening and / or VI-improving polymers.

According to another object, the invention relates to the use of a lubricant as described above as a single cylinder lubricant that can be used with any type of fuel oil whose sulfur content is less than 4.5%, preferably of which the Sulfur content is 0.5 to 4% w / w.

Preferably, the single-cylinder lubricant according to the invention can be used both with fuel oil with a sulfur content of less than 1.5% w / w and with fuel oil with a sulfur content greater than 3% w / w, or greater than 3.5% m / m.

According to a preferred embodiment, the single-cylinder lubricant according to the invention can be used both with fuel oil with a sulfur content of less than 1% w / w and with fuel oil with a sulfur content of more than 3% w / w.

According to another object the invention relates to the use of a lubricant as described above to prevent corrosion and / or reduce the formation of deposit insoluble metal salts in two-stroke marine engines during the combustion of any type of fuel oil with a sulfur content of less than 4.5% m / m.

The application as filed describes the use of one or more compounds chosen from oil-soluble fatty amines and their derivatives, for example the fatty amines and their derivatives described above, to provide an alternative BN that does not generate any hard metal deposits in cylinder lubricants for two-stroke marine diesel engine having a BN, measured by ASTM D-2896, greater than or equal to 15, preferably greater than 20, preferably greater than 30, advantageously greater than 40 milligrams of potash per gram of lubricant.

The application as filed discloses a method of manufacturing a lubricant as described above wherein the fatty amine (s) and / or their derivatives are added as a separate component of the cylinder lubricant having a BN determined according to ASTM D- 2896 greater than or equal to 15, preferably greater than 20, preferably greater than 30, advantageously greater than 40 milligrams of potash per gram of lubricant and optionally comprising one or more functional additives.

The lubricant described in the application as filed is prepared by diluting one or more marine lubricant additive concentrates in which the fatty amine (s) and / or their derivatives are incorporated.

The application as filed discloses an additive concentrate, for the preparation of cylinder lubricant having a BN determined according to ASTM D-2896 greater than or equal to 15, preferably greater than 20, preferably greater than 30, preferably greater than 30. 40 milligrams of potash per gram of lubricant, said concentrate having a BN between 250 and 300, and comprising one or more fatty amines and / or fatty amine derivatives of BN of between 150 and 600 mg of potash / g of amine according to the ASTM D-2896 standard, the mass percentage of said fatty amines and / or derivatives in the concentrate being chosen so as to provide said concentrate with a BN contribution determined according to the ASTM D-2896 standard of between 35 and 270 milligrams of potassium hydroxide per gram of concentrate.

Detailed description of the invention. Fatty amines and their derivatives as a source of alternative BN to overbased detergents :

The fatty amines used in the lubricants described in the application as filed are primary, secondary or tertiary monoamines, or polyamines containing one or more aliphatic chains, or their derivatives.

These compounds have an intrinsic basicity allowing them to be used as a significant source of BN in cylinder lubricants, in substitution for detergents, especially overbased. The intrinsic BN of the fatty amines and derivatives described in the application as filed, measured according to the ASTM D-2896 standard, is typically between 150 and 600 milligrams of potash per gram, preferably between 200 and 500 milligrams of potash per gram.

These are surfactants of cationic type whose polar head is constituted by the nitrogen atom, (and possibly by one or more oxygen atoms for the oxyamine derivatives and ethoxylated amines) and the lipophilic part by the one or more aliphatic chains.

Fatty amines are mainly obtained from carboxylic acids. These acids are dehydrated in the presence of ammonia to give nitriles, which then undergo catalytic hydrogenation to lead to primary, secondary or tertiary amines.

The starting fatty acids for obtaining fatty amines are, for example, caprylic, pelargonic, capric, undecylenic, lauric, tridecylenic, myristic, pentadecyl, palmitic, margaric, stearic, nonadecylic, arachic, heneicosanoic, behenic, tricosanoic, lignoceric, pentacosanoic acids. , cerotic, heptacosanoic, montanic, nonacosanoic, melissic, hentriacontanoic, laceroic or unsaturated fatty acids such as palmitoleic, oleic, erucic, nervonic, linoleic, a-linolenic, c-linolenic, di-homo-c-linolenic acid, arachidonic, eicosapentaenoic, docosahexanoic.

The preferred fatty acids are derived from the hydrolysis of triglycerides present in vegetable and animal oils, such as coconut oil, palm oil, olive oil, peanut oil, rapeseed oil, sunflower oil, soy oil and cotton oil. , flax, beef tallow, .... natural oils may have been genetically modified to enrich their content of certain fatty acids, for example rapeseed oil or oleic sunflower.

The fatty amines used in the lubricants according to the invention are preferably obtained from natural resources, plant or animal. Treatments that result in fatty amines from natural oils can result in mixtures of secondary and tertiary primary monoamines and polyamines.

For example, products containing, in variable proportions, all or part of the compounds corresponding to the following formulas may be incorporated into the lubricants according to the present invention:

RNH 2,

R-NH-R

R-NHCH ₂ -R

R- [NH (CH ₂ ) ₃ ] ₂ -NH ₂

R- [NH (CH ₂ ) ₃ ] _n -NH ₂

where n is an integer greater than or equal to 1 and R is a fatty chain derived from the fatty acid or acids present in the starting oil. The same fat mono or polyamine may also contain several fatty chains from different fatty acids. These products can also be used in purified form, mainly containing a single type of amines, for example mainly diamines.

Thus advantageously will be used a product consisting of diamines of formula R- [NH (CH ₂ ) ₃ ] ₂ -NH ₂ , where R may represent a plurality of fatty acids from a natural resource, for example tallow fat.

It is also possible to use purified products. For example, amines obtained from oleic acid, in particular diamines of formula R- [NH (CH ₂ ) ₃ ] ₂ -NH ₂ where R is the fatty chain of oleic acid, are advantageously used.

The amines according to the present invention are soluble in the oil matrix to facilitate their incorporation into the lubricant and to be able to more easily reach the droplets of neutralizing acid dispersed in said oil matrix, so as to be more efficient. Thus, the fatty amines of the lubricants according to the present invention are not in emulsion or microemulsion form, but well dispersed in the oil matrix.

The fatty amines according to the present invention are therefore those which comprise at least one aliphatic chain consisting of at least 16 carbon atoms, preferably at least 18 carbon atoms.

In order to avoid the gellation phenomenon sometimes observed with a high mass content of fatty amines in the lubricant, fatty amines containing between 16 and 22 carbon atoms are particularly preferred.

Indeed, the BN of the amines according to the invention being between 150 and 600, and the number of points of minimum BN provided by these amines being 10 milligram of potash per gram of lubricant, it is necessary to use them at levels minimum of the order of 2% by weight in the lubricant, but which can typically rise to values of the order of 20% by weight, for example to bring 40 BN points with an amine of BN 200, or to of the.

Derivatives of fatty amines:

In the lubricants described in the application as filed, the BN alternative to overbased detergents can be provided by fatty amine derivatives. These derivatives are, for example, ethoxylated amines, obtained by condensation of ethylene oxide with primary or secondary amines, aminoxides, resulting from the reaction of tertiary fatty amines with hydrogen peroxide, or ammonium salts. quaternaries synthesized from tertiary amines.

BN lubricants according to the present invention.

The BN of the lubricants described in the application as filed is provided by the neutral or overbased detergents based on alkali or alkaline earth metals and one or more fatty amines and / or their derivatives.

The value of this BN, measured according to ASTM D-2896 can vary from 5 to 100 mg KOH / g, or beyond. A lubricant of BN value fixed will be chosen according to the conditions of use of said lubricants and in particular according to the sulfur content of the fuel oil used and in combination with the cylinder lubricants.

The lubricants according to the present invention are suitable for use as a cylinder lubricant, irrespective of the sulfur content of the fuel oil used as fuel in the engine.

As a result, the cylinder lubricants for two-stroke marine engines according to the invention have a BN greater than or equal to 15, preferably greater than 20, preferably greater than 30, advantageously greater than 40, and preferably between 40 and 80.

According to a preferred embodiment of the invention, the lubricant formulation has a level of BN, measured according to the ASTM D-2896 standard, adapted for use with high-sulfur fuel oils containing of the order of 4, 5% w / w sulfur, that is to say a BN between 65 and 75, or equal to 70.

According to another embodiment, the BN of the lubricants according to the present invention is between 45 and 60, preferably between 45 and 55, or equal to 50.

According to one embodiment, the BN of the lubricants according to the present invention is between 55 and 60, or equal to 57, or equal to 55.

• BN_{amine lub} = contribution de l'amine au BN du lubrifiant fini
• x = % massique de l'amine dans le lubrifiant fini
• BN_amine = BN intrinsèque de l'amine seule (ASTM D 28-96).

The proportion of BN provided by the fatty amines and derivatives is at least 10 points in the lubricants described in the application as filed, preferably at least 20 points, preferably at least 30 points, even more preferably at least 40 points. BN's share of a fat amine in the lubricant (in milligram of potash per gram of finished lubricant, or "points" of BN) is calculated from its intrinsic BN measured according to ASTM D-2896 and its percentage mass in the finished lubricant: $${\mathrm{BN}}_{\mathrm{amine\; lub}}=\mathrm{x}.{\mathrm{BN}}_{\mathrm{amine}}/100$$

• BN _{amine lub} = contribution of amine to the BN of the finished lubricant
• x =% by mass of the amine in the finished lubricant
• BN _amine = intrinsic BN of the amine alone (ASTM D 28-96).

Thus, for a lubricant described in the BN 70 application, the fatty amines and derivatives provide at least 14% of the BN. For a lubricant described in the BN 55 application, the fatty amines and derivatives provide at least 18% of the BN. For a lubricant described in the application as filed BN 40, fatty amines and derivatives provide at least 25% of BN.

Since these fatty amines and their derivatives themselves have a BN between 100 and 600, preferably between 200 and 400, the mass percentage of these compounds in the lubricants described in the application as filed is greater than 1.7% (contribution of 10 BN points with an amine of BN 600), generally greater than 2%.

Fatty amines, however, do not provide all the BN in the lubricants according to the present invention. The applicant has found that the incorporation of high-grade fatty amines induces a significant drop in viscosity, so that beyond a maximum percentage of fatty amines, it is no longer possible to formulate lubricants. having the viscosity grade required for lubricant application cylinder, except to incorporate extremely high amounts of thickening additives, which would lead to unrealistic formulas from an economic point of view and deteriorate other properties of the lubricant.

Incorporation of high-grade amines is also likely to generate toxicity problems.

In order to formulate lubricants suitable for both high and low sulfur content, one will typically choose to work at a BN of about 55, or 57, or 70, providing at least 10 BN points per second. overbased detergents. Thus, a maximum of 60 points of BN will generally be provided by the fatty amines, which corresponds to a maximum mass percentage of fatty amines of the order of 10, 15, 30 or 40%, for amines respectively of BN 600, 400, 200 or 150.

Surprisingly, the Applicant has also found that lubricants combining a BN supply with amines and overbased detergents did not exhibit a satisfactory neutralization efficiency (that is to say of the order of 100 or above), only up to a maximum level of BN provided by the metal carbonate salts of the overbased detergents.

Without wishing to be bound by any theory, it seems that these metal carbonates, which constitute the ultimate reserve of basicity for use of the cylinder lubricant with the high sulfur contents, have a slower sulfuric acid neutralization kinetics than the metallic soaps and amines.

Thus, the share of BN provided by the metal salts of carbonates from overbased detergents is at most 20 points (20 milligrams of potash per gram of lubricant) in the lubricants according to the present invention. This part of BN, hereinafter referred to as "BN carbonate" or "BN CaCo3" is measured according to the method described in Example 1 below.

Conventional oils of BN greater than or equal to 40, thus reformulated according to the invention by substituting fatty amines for overbased detergents, so that they provide at least 10 points of BN in the lubricant, preferably at least 30 points of BN in the lubricant, can correctly prevent corrosion problems when using high-sulfur fuel oils (of the order of 4.5% m / m).

They also make it possible to reduce the formation of insoluble metallic salt deposits providing overbasing (for example CaCO ₃ ) when using low-sulfur fuel oils (1.5% w / w and less). This reduction is directly related to the lowering of the overbased detergent content made possible in the present formulation configuration.

Thus, the lubricants according to the present invention, and in particular those of BN between 65 and 75, for example BN 70, can be used with both high and low sulfur fuel oils.

Detergents, overbased or not.

The detergents used in the lubricant compositions according to the present invention are well known to those skilled in the art.

The detergents commonly used in the formulation of lubricating compositions are typically anionic compounds having a long lipophilic hydrocarbon chain and a hydrophilic head. The associated cation is typically a metal cation of an alkali or alkaline earth metal.

The detergents are preferably chosen from alkali metal or alkaline earth metal salts of carboxylic acids, sulphonates, salicylates and naphthenates, as well as the salts of phenates.

The alkaline and alkaline earth metals are preferably calcium, magnesium, sodium or barium.

These metal salts may contain the metal in an approximately stoichiometric amount. In this case, we speak of non-overbased or "neutral" detergents, although they also bring some basicity. These "neutral" detergents typically have a BN, measured according to ASTM D2896, less than 150 mg KOH / g, or less than 100, or even less than 80 mg KOH / g.

This type of so-called neutral detergents can contribute in part to the BN lubricants according to the present invention. For example, neutral detergents of carboxylates, sulphonates, salicylates, phenates, alkali metal and alkaline earth metal naphthenates, for example calcium, sodium, magnesium or barium, will be used.

When the metal is in excess (in an amount greater than the stoichiometric amount), we are dealing with so-called overbased detergents. Their BN is high, greater than 150 mg KOH / g, typically between 200 and 700 mg KOH / g, generally between 250 and 450 mg KOH / g.

The excess metal providing the overbased detergent character is in the form of oil insoluble metal salts, for example carbonate, hydroxide, oxalate, acetate, glutamate, preferably carbonate.

In the same overbased detergent, the metals of these insoluble salts may be the same as those of the oil-soluble detergents or may be different. They are preferably selected from calcium, magnesium, sodium or barium.

The overbased detergents are thus in the form of micelles composed of insoluble metal salts maintained in suspension in the lubricating composition by the detergents in the form of oil-soluble metal salts.

These micelles may contain one or more types of insoluble metal salts, stabilized by one or more detergent types.

Overbased detergents with a single type of detergent soluble metal salt will generally be named after the nature of the hydrophobic chain of the latter detergent.

Thus, they will be said phenate, salicylate, sulfonate, naphthenate depending on whether this detergent is respectively a phenate, salicylate, sulfonate, or naphthenate.

The overbased detergents will be said to be of mixed type if the micelles comprise several types of detergents, different from each other by the nature of their hydrophobic chain.

For use in the lubricating compositions according to the present invention, the oil-soluble metal salts will preferably be phenates, sulphonates salicylates, and mixed detergents phenate-sulphonate and / or salicylates calcium, magnesium, sodium or barium.

The insoluble metal salts providing the overbased character are alkali and alkaline earth metal carbonates, preferentially calcium carbonate.

The overbased detergents used in the lubricating compositions according to the present invention will preferably be phenates, sulphonates, salicylates and mixed detergents phenates-sulphonates-salicylates, overbased with calcium carbonate.

BN supplied by the detergents in the lubricants according to the invention :

In the lubricants according to the present invention, part of the BN is provided by the insoluble metal salts of the overbased detergents, in particular the metal carbonates.

The weight percentage of overbased detergents relative to the total weight of lubricant is thus chosen so that the BN supplied by the carbonate metal salts represents a contribution of at most 20 milligrams of potash per gram of lubricant to the total BN of said lubricant cylinder.

The BN supplied by the carbonate metal salts is measured on the overbased detergent alone and / or on the final lubricant according to the method described in Example 1. Typically in an overbased detergent, the BN supplied by the metal salts of carbonate represents 50 to 95% of the total BN of the overbased detergent alone.

These insoluble metal salts also have a favorable anti-wear effect provided that they are kept dispersed in the lubricant in the form of stable micelles, which is not the case when they are in excess of the amount of sulfuric acid to neutralize in service.

Thus, according to a preferred embodiment of the invention, the insoluble metal salts of the overbased detergents provide at least 5 milligrams of potash per gram of lubricant (or 5 "points of BN") in the lubricants according to the present invention, preferably at least 10 BN points.

On the other hand, the detergents themselves, which are metal soaps of the essentially phenate or salicylate type, or sulfonate, also contribute to the BN of the lubricants according to the present invention. This BN contribution, hereinafter referred to as "organic BN", comes from both neutral and overbased detergents.

These metal soaps have a positive effect on the thermal resistance of the cylinder lubricants. Thus, preferentially, the lubricants according to the present invention have a certain portion of their BN provided by these metal soaps.

According to a preferred embodiment, the organic BN provided by the metal soaps represents a contribution of at least 5 milligrams of potash per gram of lubricant, preferably at least 10 milligrams of potash per gram of lubricant, in the cylinder lubricants according to the present invention.

• le BN apporté par les amines grasses, déterminé en fonction du BN des amines mesurées par ASTM 2896 et du pourcentage massique d'amines grasses.
• Le BN apporté par les sels métalliques insolubles des détergents surbasés, appelé par extension « BN carbonate » ou « BN CaCO3 », et mesuré par la méthode décrite dans l'exemple 1 ci après.
• Le BN « organique » apporté par les savons métalliques des détergents surbasés et éventuellement neutres, et obtenu par différence entre le BN total du lubrifiant et les autres contributions.

The BN of the lubricants according to the present invention, measured according to ASTM D2896, therefore comprises at least 3 distinct components:

• the BN supplied by the fatty amines, determined according to the BN of the amines measured by ASTM 2896 and the mass percentage of fatty amines.
• The BN provided by the insoluble metal salts of the overbased detergents, called by extension "BN carbonate" or "BN CaCO3", and measured by the method described in Example 1 below.
• The "organic" BN provided by the metal soaps of the overbased and possibly neutral detergents, and obtained by difference between the total BN of the lubricant and the other contributions.

Base oils.

In general, the base oils used for the formulation of lubricants according to the present invention can be oils of mineral, synthetic or vegetable origin as well as their mixtures.

The mineral or synthetic oils generally used in the application belong to one of the classes defined in the API classification as summarized in the table below. Saturated content Sulfur content Viscosity index Group 1 Mineral oils <90% > 0.03% 80 ≤ VI <120 Group 2 Hydrocracked oils ≥ 90% ≤ 0.03% 80 ≤ VI <120 Group 3 Hydroisomerized oils ≥ 90% ≤ 0.03% ≥ 120 Group 4 PAO Group 5 Other bases not included in groups 1 to 4

The Group 1 mineral oils can be obtained by distillation of selected naphthenic or paraffinic crudes and then purification of these distillates by methods such as solvent extraction, solvent or catalytic dewaxing, hydrotreatment or hydrogenation.

The oils of Groups 2 and 3 are obtained by more severe purification methods, for example a combination among hydrotreatment, hydrocracking, hydrogenation and catalytic dewaxing.

Examples of Group 4 and 5 synthetic bases include poly-alpha olefins, polybutenes, polyisobutenes, alkylbenzenes.

These base oils can be used alone or as a mixture. A mineral oil can be combined with a synthetic oil.

Cylinder oils for 2-stroke marine diesel engines have a SAE-40 SAE-40 viscometric grade, typically SAE-50 equivalent to a kinematic viscosity at 100 ° C of between 16.3 and 21.9 mm ² / s.

Grade 40 oils have a kinematic viscosity at 100 ° C of between 12.5 and 16.3 cSt.

Grade 50 oils have a kinematic viscosity at 100 ° C of 16.3 to 21.9 cSt.

Grade 60 oils have a kinematic viscosity at 100 ° C of 21.9 to 26.1 cSt.

According to the uses of the profession, it is preferred to formulate cylinder oils for 2-stroke marine diesel engines having a kinematic viscosity at 100 ° C. of between 18 and 21.5, preferably between 19 and 21.5 mm 2 / s (Cst).

This viscosity can be obtained by mixing additives and base oils, for example containing Group 1 mineral bases such as Neutral Solvent (for example 500NS or 600 NS) and Brightstock bases. Any other combination of mineral, synthetic or vegetable bases having, in admixture with the additives, a viscosity compatible with the grade SAE-50 may be used.

Typically, a conventional cylinder lubricant formulation for slow 2-cycle marine diesel engines is SAE 40 to SAE60, preferably SAE50 (SA37 J300) and includes at least 50% by weight of original lubricating base oil. mineral and / or synthetic, suitable for use in a marine engine, for example of API Group 1, that is to say obtained by distillation of selected crudes and purification of these distillates by processes such as solvent extraction , solvent or catalytic dewaxing, hydrotreatment or hydrogenation. Their Viscosity Index (VI) is between 80 and 120; their sulfur content is greater than 0.03% and their saturated content is less than 90%.

Typically, a conventional cylinder lubricant formulation for slow 2-stroke marine diesel engines contains from 18 to 25% by weight, based on the total weight of lubricant, of a BSS type I base oil base oil (residue). distillation, kinematic viscosity at 100 ° C close to 30 mm ² / s, typically between 28 and 32 mm ² / s, and density at 15 ° C between 895 and 915 kg / m3), and 50 to 60% by weight, based on the total weight of lubricant, of a Group 600 NS type base oil (distillate, density at 15 ° C between 880 and 900 kg / m3, kinematic viscosity at 100 ° C close to 12 mm ² / s).

Thickening additives :

In the lubricants according to the present invention, the applicant has demonstrated that the introduction of significant amounts of fatty amines (typically of the order of 5 to 15%, or greater than 10%, or of the order 20% by weight) has the effect of lowering the viscosity of the lubricant. Thus, it may be necessary, especially for the highest amine contents, to introduce into the lubricants according to the present invention thickening and / or viscosity index improvers having the effect of increasing the viscosity of the lubricant. . This makes it possible to formulate viscosimetric-grade cylinder lubricants adapted to their use.
Thus, according to one embodiment, in the cylinder lubricants according to the invention, the base oil or oils are partially or totally substituted by one or more thickening additives whose role is to increase the viscosity of the composition, as hot as cold, or by viscosity index (VI) improving additives.

These additives are most often polymers of low molecular weight, of the order of 2000 to 50 000 dalton (Mn).

They may be chosen from PIBs (of the order of 2000 daltons), polyacrylate or poly methacrylates (of the order of 30000 daltons), olefin-copolymers, olefin and alpha olefin copolymers, EPDM, polybutenes , Poly-alphaolefins high molecular weight (viscosity 100 ° C> 150), Styrene-Olefin copolymers, hydrogenated or not.

In the cylinder lubricants according to the invention, the polymers used to partially or totally substitute one or more of the base oils are preferably the aforementioned thickeners of the PIB type (for example marketed under the name Indopol H2100).

They will preferably be present in amounts of 5 to 20% by weight in the cylinder lubricants according to the invention, preferably between 8 and 20% for amine contents greater than 15% by weight.

Anti-wear additives :

Lubricants according to the present invention contain, at BN equivalent, a lower amount of overbased detergents than that present in conventional cylinder lubricants. Thus, a BN 70 cylinder lubricant usually contains about 25% by weight of overbased detergents, whereas in the lubricants of the BN 70 invention, this content can fall around 15% or even be less than 5%. .

However, as mentioned above, these compounds can have a positive anti-wear effect. This is why the cylinder lubricants according to the invention will preferably comprise antiwear additives.

The anti-wear additives protect the friction surfaces by forming a protective film adsorbed on these surfaces. The most commonly used is Zinc di thiophosphate or DTPZn. This category also contains various phosphorus, sulfur, nitrogen, chlorine and boron compounds.

There is a wide variety of anti-wear additives, but the most used category is that of phospho-sulfur-containing additives such as metal alkylthiophosphates, in particular zinc alkylthiophosphates, and more specifically zinc dialkyldithiophosphates or DTPZn. The preferred compounds have the formula Zn ((SP (S) (OR 1) (OR 2)) 2, or R 1 and R 2 are alkyl groups, preferably containing 1 to 18 carbon atoms, and DTPZn is typically present at in the range of 0.1 to 2% by weight.

Amine phosphates, polysulfides, especially sulfur-containing olefins, are also commonly used antiwear additives.

Lubricating compositions containing nitrogenous and sulfur-containing anti-wear and extreme pressure additives, such as, for example, metal dithiocarbamates, in particular molybdenum dithiocarbamate, are also usually encountered in lubricating compositions. Glycerol esters are also anti-wear additives. Mention may be made, for example, of mono, di and trioleates, monopalmitates and monomyristates.

The anti-wear and extreme pressure additives are present in lubricant compositions at contents of between 0.01 and 6%, preferably between 0.1 and 4%.

According to a preferred embodiment, the cylinder lubricants according to the present invention contain at least 0.5% by weight of one or more anti-wear additives.

The preferred anti-wear agents are of the DTPZn type.

Dispersant additives.

Dispersants are well known additives used in the formulation of lubricating composition, especially for application in the marine field. Their primary role is to maintain in suspension the particles present initially or appearing in the lubricant composition during its use in the engine. They prevent their agglomeration by playing on steric hindrance. They can also have a synergistic effect on the neutralization.

The dispersants used as lubricant additives typically contain a polar group, associated with a relatively long hydrocarbon chain, generally containing from 50 to 400 carbon atoms. The polar group typically contains at least one nitrogen, oxygen or phosphorus element.

The compounds derived from succinic acid are dispersants particularly used as lubrication additives. Especially succinimides, obtained by condensation of succinic anhydrides and amines, succinic esters obtained by condensation of succinic anhydrides and alcohols or polyols.

These compounds can then be treated with various compounds including sulfur, oxygen, formaldehyde, carboxylic acids and compounds containing boron or zinc to produce, for example, borated succinimides or zinc-blocked succinimides.

Mannich bases, obtained by polycondensation of phenols substituted with alkyl groups, formaldehyde and primary or secondary amines, are also compounds used as dispersants in lubricants.

According to one embodiment of the present invention, at least 0.1% of a dispersing additive is used. It is possible to use a dispersant in the family of succinimide PIBs, for example borated or blocked with zinc.

Other functional additives.

The lubricant formulation according to the present invention may also contain any functional additives adapted to their use, for example anti-foam additives to counteract the effect of detergents, which may for example be polar polymers such as polymethylsiloxanes, polyacrylates, antioxidant additives and / or or anti rust, for example organo metal detergents or thiadiazoles. These are known to those skilled in the art. These additives are generally present at a content by weight of 0.1 to 5%.

According to the present invention, the compositions of the lubricants described refer to the compounds taken separately before mixing, it being understood that said compounds may or may not retain the same chemical form before and after mixing. Preferably, the lubricants according to the present invention obtained by mixing the compounds taken separately are not in the form of emulsion or microemulsion.

Additive concentrates for marine lubricants :

The fatty amines and derivatives contained in the lubricants described in the application as filed may in particular be incorporated in a lubricant as separate additives. However, the fatty amines and derivatives contained in the lubricants described in the application as filed may also be incorporated into a marine lubricant additive concentrate.

Conventional marine cylinder lubricant additive concentrates generally consist of a mixture of the constituents described above, detergents, dispersants, other functional additives, pre-dilution base oil, in proportions which make it possible to obtain, after dilution, in a base oil for cylinder lubricants having a BN determined according to ASTM D-2896 greater than or equal to 15, preferably greater than 20, preferably greater than 30, advantageously greater than 40 milligrams of potash per gram of lubricant. This mixture generally contains, relative to the total weight of concentrate, a detergent content greater than 80%, preferably greater than 90%, a dispersant additive content of 2 to 15%, preferably 5 to 10%, a content of other functional additives from 0 to 5%, preferably from 0.1 to 1%. The BN of said concentrates, measured according to ASTM D 2896, is generally between 250 and 300 milligrams of potash per gram of concentrate, typically of the order of 275 milligrams of potash per gram of concentrate.

The application as filed discloses an additive concentrate, for the preparation of cylinder lubricant having a BN determined according to ASTM D-2896 greater than or equal to 15, preferably greater than 20, preferably greater than 30, preferably greater than 30. 40 milligrams of potash per gram of lubricant, said concentrate having a BN between 250 and 300, and comprising one or more fatty amines and / or fatty amine derivatives of BN of between 150 and 600 mg of potash / g of amine according to the ASTM D-2896 standard, the mass percentage of said fatty amines and / or derivatives in the concentrate being chosen so as to bring to said concentrate a BN contribution determined according to the ASTM D-2896 standard of between 35 (14% of 250 ) and 270 (90% of 300) milligrams of potash per gram of concentrate.

The mass percentage of said fatty amines and / or derivatives in the concentrate is chosen so as to bring to said concentrate a BN contribution determined according to the ASTM D-2896 standard of between 60 (25 % of 250) and 225 (75 % of 300). ) milligrams of potash per gram of concentrate.

The mass percentage of said fatty amines and / or derivatives in the concentrate is chosen so as to provide said concentrate with a BN contribution determined according to ASTM D-2896 between 135 (55 % of 250) and 225 (75 % of 300). ) milligrams of potash per gram of concentrate.

The fatty amines of the concentrates described in the application as filed are those described above and in the examples below as a source of BN alternative detergents.

The concentrates described in the application as filed also contain base oil in a small amount, but sufficient to facilitate the use of said additive concentrates.

Measuring the performance differential, between a conventional reference lubricant and a lubricant according to the invention.

This measurement is characterized by a neutralization efficiency index measured according to the enthalpic test method described precisely in the examples and in which the progress of the exothermic neutralization reaction is followed by the rise in temperature observed when said lubricant containing the basic sites is put in the presence of sulfuric acid.

Of course, the present invention is not limited to the examples and to the embodiment described and shown, but it is capable of numerous variants accessible to those skilled in the art.

Examples : Example 1: This example is intended to describe the method for measuring the contribution of the insoluble metal salts present in the BN-based overbased detergents of the lubricant compositions containing said overbased detergents:

• ▪ BN carbonate, amené par le surbasage du détergent par des carbonates métalliques, généralement carbonate de calcium, désigné ci après par «BN_CaCO3»,
• ▪ BN dit organique amené par le savon métallique du détergent du type essentiellement phénate ou salicylate, ou sulfonate.

Le BN carbonate, désigné ci après par BNCaCO3 est mesuré, sur l'huile finie ou les détergents surbasés seuls, selon le mode opératoire suivant. Celui ci à pour principe d'attaquer le surbasage, carbonate (de calcium), de l'échantillon par de l'acide sulfurique. Ce carbonate se transforme en gaz carbonique suivant la réaction ;

The total measurement of the basicity (so-called BN or Base Number) of the finished lubricating oils or overbased detergents is done by the ASTM D2896 method. This BN consists of two distinct forms:

• ▪ BN carbonate, brought by the overbasing of the detergent by metal carbonates, generally calcium carbonate, hereinafter referred to as "BN _CaCO3 ",
• ▪ BN said organic brought by the metallic soap of the detergent essentially of phenate type or salicylate, or sulfonate.

The BN carbonate, hereinafter referred to as BNCaCO3, is measured on the finished oil or the overbased detergents alone, according to the following procedure. This one has for principle to attack the overbasing, carbonate (calcium), of the sample by sulfuric acid. This carbonate is transformed into carbon dioxide according to the reaction;

The volume of the reactor being constant, the pressure increases proportionally with the release of CO ₂ .
Procedure : in a reaction vessel with a volume of 100 ml, fitted with a stopper on which a differential pressure gauge has been fitted, the necessary quantity of product whose BN _CaCO3 is to be measured is _weighed so as not to exceed the limit of measuring the differential pressure gauge, which is 600 mb increase in pressure. The quantity is determined from the graph figure 2 , indicating for each mass of product (1 to 10 grams, right from left to right in the figure) the pressure measured on the differential pressure gauge (which corresponds to the pressure increase due to the release of CO ₂ ) as a function of the part BN _CaCO3 of the sample. If the result of BN _CaCO3 is unknown, an average product amount of about 4 g is weighed. In all cases, the sample mass (m) is recorded.
The reaction vessel may be pyrex, glass, polycarbonate, ... or any other material that promotes heat exchange with the surrounding environment, so that the internal temperature of the vessel equilibrates rapidly with that of the ambient environment.

A small amount of 600 NS type fluid base oil is introduced into the reaction vessel containing a small magnet bar.
About 2 ml of concentrated sulfuric acid is placed in the reaction vessel, being careful not to stir the medium at this stage.
The cap and pressure gauge assembly is screwed onto the reaction vessel. The threads can be greased. We tighten to have a perfect seal.
Stirring is started, and the time required for the pressure to stabilize and the temperature to equilibrate with the ambient medium is stirred. A time of 30 minutes is enough. Note the pressure increase P and the ambient temperature T ° C (σ).
The whole is cleaned with a solvent of the heptane type.

Calculation method

• P = Pression partielle de CO2(Pa) (1Pa = 10^-2 mb)
• V = Volume du récipient (m³).
• R = 8.32 (J). $$T=\mathrm{273}+\sigma \left(°C\right)=\left(°K\right).$$
  
  n = nombre de moles de CO₂ dégagé $${\mathrm{P\; CO}}_{}$$$${}_2=\frac{{\mathrm{<figure-callout\; id="2"\; label="n\; CO"\; filenames="imgf0001.png"\; state="\{\{state\}\}">n\; CO</figure-callout>}}_2*\mathrm{R}*\mathrm{T}}{\mathrm{V}}*{10}^{-2}$$
  

To calculate the pressure, the ideal gas formula is used. $$\mathit{PV}=\mathit{nRT}$$

• P = Partial pressure of CO2 (Pa) (1Pa = 10 ^-2 mb)
• V = Volume of the container (m ³ ).
• R = 8.32 (J). $$T=\mathrm{273}+\sigma \left(°\mathrm{VS}\right)=\left(°K\right).$$
  
  n = number of moles of CO ₂ released $${\mathrm{<figure-callout\; id="2"\; label="P\; CO"\; filenames="imgf0001.png"\; state="\{\{state\}\}">P\; CO</figure-callout>}}_2=\frac{{\mathrm{<figure-callout\; id="2"\; label="n\; CO"\; filenames="imgf0001.png"\; state="\{\{state\}\}">n\; CO</figure-callout>}}_2*\mathrm{R}*\mathrm{T}}{\mathrm{V}}*{10}^{-2}$$
  

Calculation of the number of moles of CO ₂ .

$$m*B\mathrm{NOT}\mathrm{}\mathit{carbonate}=m\mathrm{boy\; Wut}\mathrm{}KOH\mathrm{}\mathit{equivalent}.$$

• m = mass of product in grams
• BN carbonate = BN expressed in equivalent KOH for 1g. $$\frac{\mathrm{m}*\mathrm{BN\; carbonate}*\frac{44}{2*56.1}}{1000}=\mathrm{boy\; Wut}\mathrm{}d\mathrm{<figure-callout\; id="2"\; label="e\; VS\; O"\; filenames="imgf0001.png"\; state="\{\{state\}\}">e\; </figure-callout>}\mathrm{}\mathrm{VS}{O}_{}{}_2\mathrm{}\mathit{cleared},\mathrm{}soit\mathrm{}e\mathrm{not}\mathrm{}\mathrm{not}ombre\mathrm{}de\mathrm{}moles\mathrm{}d\mathrm{<figure-callout\; id="2"\; label="e\; VS\; O"\; filenames="imgf0001.png"\; state="\{\{state\}\}">e\; </figure-callout>}\mathrm{}\mathrm{VS}{O}_{}{}_2$$
  
  cleared: $$\frac{\mathrm{m}*\mathrm{BN\; carbonate}*44*{10}^{-3}}{44*2*56.1}=\mathrm{m}*\mathrm{BN\; carbonate\; *\; 0.0089}{10}^{-3}$$
  

Calculation formula for CO pressure ₂ according to the BN carbonate.

$$\boxed{{\mathrm{<figure-callout\; id="2"\; label="P\; CO"\; filenames="imgf0001.png"\; state="\{\{state\}\}">P\; CO</figure-callout>}}_2=\frac{\mathrm{m}*\mathrm{BN\; carbonate}*0.0089\mathrm{}{10}^{-3}*\mathrm{R}*\mathrm{T}*{10}^{-2}}{\mathrm{V}}}$$

Formula for calculating BN carbonate from CO pressure ₂ .

$$\boxed{\mathrm{BN\; carbonate}=\frac{\mathrm{P}*\mathrm{V}}{\mathrm{m}*0.0089*{10}^{-3}*\mathrm{R}*\mathrm{T}*{10}^{-2}}}$$

• P CO₂ = valeur lue sur le manomètre différentiel, en mbars = P lue
• V = volume du récipient en m³ = 0.0001.
• R = 8.32 (J).

$$T=\mathrm{273}+\sigma \left(°C\right)=\left(°K\right).\sigma =Température\mathrm{}ambiante\mathrm{}\mathit{lue}.$$

m = masse de produit introduit dans le vase de réaction. $$\boxed{\mathrm{BN\; carbonate}=\frac{\mathrm{P\; lue}*0.0001}{\mathrm{m}*0.0089*{10}^{-3}*8.32*\left(273*\sigma \mathrm{lue}\right)*{10}^{-2}}}$$

$$\boxed{\mathrm{BN\; carbonate}=\frac{\mathrm{P\; lue}}{\mathrm{m}*0.0074*\mathrm{R}*\left(273*\sigma \mathrm{lue}\right)}}$$

By setting the values related to the test conditions, we obtain the simplified formula:

• P CO ₂ = value read on the differential pressure gauge, in mbar = P read
• V = vessel volume in m ³ = 0.0001.
• R = 8.32 (J).

$$T=\mathrm{273}+\sigma \left(°\mathrm{VS}\right)=\left(°K\right).\sigma =Temp\mathrm{ed}r\mathrm{at}ture\mathrm{}\mathrm{at}mbi\mathrm{at}\mathrm{not}te\mathrm{}\mathit{read}.$$

m = mass of product introduced into the reaction vessel. $$\boxed{\mathrm{BN\; carbonate}=\frac{\mathrm{P\; read}*0.0001}{\mathrm{m}*0.0089*{10}^{-3}*8.32*\left(273*\sigma \mathrm{read}\right)*{10}^{-2}}}$$

$$\boxed{\mathrm{BN\; carbonate}=\frac{\mathrm{P\; read}}{\mathrm{m}*0.0074*\mathrm{R}*\left(273*\sigma \mathrm{read}\right)}}$$

The result obtained is the BN _CaCO3 expressed in mgKOH / g.

The BN supplied by the metallic soaps of detergents, also designated by "organic BN", is obtained by difference between the total BN according to ASTM D2896 and the BN _CaCO3 thus measured.

Example 2 : This example aims to describe the enthalpic test for measuring the neutralization efficiency of lubricants vis-à-vis sulfuric acid.

The availability or accessibility of the basic sites included in a lubricant, in particular lubricant cylinder for marine engine two times, vis-à-vis the acid molecules, can be quantified by a dynamic test of speed monitoring or kinetics of neutralization.

Principle :

The acid-base neutralization reactions are generally exothermic and it is therefore possible to measure the heat release obtained by reaction of sulfuric acid with the lubricants to be tested. This evolution is followed by the evolution of the temperature over time in an adiabatic reactor of the DEWAR type.

From these measurements, it is possible to calculate an index quantifying the effectiveness of a lubricant according to the present invention with respect to a lubricant taken as a reference, and for an amount of added acid representing a fixed number of BN points to be neutralized. . The BN of the lubricants to be tested is preferably in excess of the BN required to neutralize the amount of added acid. To test BN 70 lubricants, the following examples thus add an amount of acid corresponding to the neutralization of 55 BN points.

The efficiency index is calculated relative to the reference oil to which is assigned the value of 100. This is the ratio between the reference neutralization reaction times (S _ref) and the sample measured (S _mes ): $$\mathrm{Neutralization\; efficiency\; index}={\mathrm{S}}_{\mathrm{ref}}/{\mathrm{S}}_{\mathrm{my}}\times 100$$

The values of these neutralization reaction times, which are of the order of a few seconds, are determined from the acquisition curves of the increase in temperature as a function of time during the neutralization reaction. (See curve figure 1 ).

The duration S is equal to the difference t _f - t _i between the time at the end of reaction temperature and the time at the reaction start temperature.

The time t _i at the reaction start temperature corresponds to the first rise in temperature after stirring is started.

The time t _f at the final reaction temperature is that from which the temperature signal remains stable for a duration greater than or equal to the half-duration of reaction.

The lubricant is all the more effective as it leads to short periods of neutralization and therefore to a high index.

Material used :

The reactor and agitator geometries as well as the operating conditions were chosen so as to be in a chemical regime, where the effect of the diffusional stresses in the oil phase is negligible.

Therefore in the configuration of the material used, the fluid height must be equal to the inside diameter of the reactor, and the stirring propeller must be positioned at about 1/3 of the height of the fluid.

The apparatus consists of a cylindrical adiabatic reactor of 300 ml, the inner diameter of which is 52 mm and the internal height 185 mm, of a stirring rod provided with a propeller with inclined blades, 22 mm in diameter; the diameter of the blades is between 0.3 and 0.5 times the diameter of the DEWAR, that is to say from 15.6 to 26 mm.

The position of the propeller is set at a distance of about 15 mm from the bottom of the reactor. The stirring system is driven by a variable speed motor of 10 to 5000 rpm and a temperature acquisition system as a function of time.

This system is suitable for measuring reaction times of the order of 5 to 20 seconds and the temperature rise measurement of a few tens of degrees from a temperature of about 20 ° C to 35 ° C preferably about 30 ° C. The position of the temperature acquisition system in the DEWAR is fixed.

The stirring system will be adjusted so that the reaction proceeds in a chemical regime: in the configuration of the present experiment, the speed of rotation is set at 2000 rpm, and the position of the system is fixed.

Furthermore, the chemical regime of the reaction is also dependent on the oil height introduced into the DEWAR, which must be equal to the diameter of the latter, and which corresponds in this experiment to a mass of about 86. g of the lubricant tested.

To test the BN 70 lubricants, the amount of acid corresponding to the neutralization of 55 BN points is introduced into the reactor.

4.13 g of 95% concentrated sulfuric acid and 85.6 g of lubricant to be tested are introduced into the reactor for a BN 70 lubricant.

After setting up the stirring system inside the reactor so that the acid and the lubricant mix well and repeatedly between two tests, agitation is started to follow the reaction in chemical regime. The acquisition system is permanent.

Implementation of the enthalpic test - calibration :

To calculate the efficiency indices of the lubricants according to the present invention by the method described above, we have chosen to take as a reference the neutralization reaction time measured for a two-stroke marine engine cylinder oil of BN 70 (measured by ASTM D-2896), not containing fatty amines according to the present invention.

This oil is obtained from a mineral base obtained by mixing a distillate of density at 15 ° C of between 880 and 900 Kg / m ³ with a distillation residue having a density of between 895 and 915 Kg / m. ³ (Brightstock) in a distillate / residue ratio of 3.

To this base is added a concentrate in which there is a BN overbased calcium sulfonate equal to 400 mg KOH / g, a dispersant, a BN-based calcium phenate equal to 250 mg KOH / g. This oil is formulated specifically to have sufficient neutralization capacity to be used with high sulfur fuels, namely S contents above 3% or even 3.5%.

The reference lubricant contains 25.50% by weight of this concentrate. Its BN of 70 is exclusively provided by the overbased detergents (phenates and overbased sulfonates) contained in said concentrate.

This reference lubricant has a viscosity at 100 ° C of between 18 and 21.5 mm ² / s.

The neutralization reaction time of this oil (hereinafter referred to as Href) is 10.59 seconds and its neutralization efficiency index is set to 100.

EXAMPLE 3 This example describes, by way of comparison, the influence of the contribution of the BN provided by the carbonate metal salts on the performance of the cylinder oils, namely their neutralization efficiency.

In this example, several BN 70 cylinder oils A, B, C are used, where part of the BN is supplied, as in the reference oil, with a concentrate of overbased detergents, and another part is provided by a mixture of of fatty polyamines obtained from tallow, mainly containing palmitic, stearic and oleic acids. This amine mixture has a BN of 460 mg KOH / g. It consists of compounds of formula R [NH- (CH ₂ ) ₃ ] _n NH ₂ , where R represents the fatty chain of palmitic, stearic or oleic acids, and n is an integer between 0 and 3.

The reference is the two-stroke marine engine cylinder oil of BN 70 referenced Href in the previous example.

Table 1 below lists the characteristics of the reference and the samples tested, as well as the values of their efficiency indices. Table 1 H ref AT B VS Composition% mass Concentrated phenates + overbased sulfonates 25.50 21,30 17,10 12,90 (Poly) fatty amines, BN 460 mg KOH / g, ASTM D2896 0.00 2.50 5.00 7.50 Gr I base oils 74.50 76.20 77.90 79,60 properties KV 100 (Cst), ASTMD445 20.5 19.21 18.36 16.51 KV 40 (Cst), ASTMD445 243.7 221.1 208.3 178 Total BN (mg KOH / g, ASTM D-2896.) 70.1 71 69.4 73.4 Of which BN supplied with fatty amines (mg KOH / g, ASTM D-2896) 0 (0% of the BN) 11.50 (16%) 23 (33%) 34.50 (47%) Of which BN CaCO3 (mg KOH / g) 51.0 (74% of the BN) 42.6 (60%) 34.2 (49%) 25.8 (35%) Neutralization efficiency index (IE) 100 59 65 76

Note that the lubricant neutralization efficiency index is significantly less than 100 when the contribution of BN provided by the metal carbonate salts is greater than 20 milligrams of potassium hydroxide per gram of lubricant.

Example 4 This example according to the invention describes the influence of the contribution of the BN provided by the metal salts of carbonate on the performance of the cylinder oils, namely the neutralization efficiency.

The reference is the two-stroke marine engine cylinder oil of BN 70 referenced Href in Example 1.

The oils G to J comprise, as a source of BN alternative to overbased detergents, a compound comprising predominantly a fatty diamine obtained from oleic acid, of formula RNH (CH ₂ ) ₃ NH ₂ , where R represents the fatty chain of oleic acid. The BN of this compound is 320 mg KOH / g (Dinoram O).

The oils K and L comprise, as source of BN alternative to overbased detergents, a compound comprising predominantly a C16 fatty amine of nature dimethyl hexadecyl amine. The BN of this compound is 200 mg KOH / g (Genamine 16R).

Fatty amines bring, in this example, about 40 BN points out of a total of 70, or about 57%. The remainder of the BN is provided by neutral phenate, overbased phenate and overbased sulfonate detergents.

Note that the lubricant neutralization efficiency index is greater than 100 when the contribution of BN provided by the metal carbonate salts is less than 20 milligrams of potassium hydroxide per gram of lubricant.

Moreover, to compensate for the drop in viscosity generated by the introduction of fatty amines and to obtain lubricants that meet the requirements for use as a cylinder oil for a two-cycle marine diesel engine, PIB has been introduced into the formulas.

Furthermore, it has been found that the oil G exhibited poor anti-wear performance (as measured, for example, in the ASTM D2670 test carried out in the FALEX pin & vee block machine), compared with the Href reference. We have therefore sought to compensate for this drop in wear performance by adding a DTPZn type antiwear in oils H, I, J, K, L.

This drop in performance is probably due to the lowering of the content of overbased detergents, which, in the form of stable micelles, has a positive anti-wear effect (conversely, when the micelles are destabilized, for example when the overbased detergents are in excess over the amount of acid generated in operation, there is formation of hard metal deposits that generate wear).

The characteristics and the performances of the oils thus formulated are summarized in Table 2. The oils H, I, J, K are preferred oils according to the invention, with an efficiency index comparable to or even greater than that of the reference, and a viscosity grade for use as a cylinder lubricant. Table 2 H ref BOY WUT H I J K The Composition% mass overbased phenates and / or sulfonates 25.50 4.00 4.00 4.00 11,00 4.00 4.00 Neutral Phenates 9.00 9.00 9.00 9.00 9.00 Oleic fatty diamines, BN 320 mg KOH / g, ASTM D2896 12.50 12.50 12.50 12.50 Genamine 16 R BN 200 mg KOH / g, ASTM D2896 20.00 20.00 Gr I base oils 74.50 73.45 72.95 65,00 66,00 50.55 57.50 GDP Indopol H2100 7.95 8.95 14,90 7.95 DTPZn 0.50 0.50 0.50 0.50 0.50 dispersed 1.05 1.05 1.05 1.05 1.05 1.05 properties KV 100 (Cst), ASTM D445 20.52 21.89 21,47 19.56 20,16 19.83 13.40 KV 40 (Cst), ASTM D445 243.7 250.4 251 197.29 202.50 165.54 99.80 Total BN (mg KOH / g, ASTM D-2896.) 70.1 70 71 72 70 70 69.6 Of which BN supplied with fatty amines (mg KOH / g, ASTM D-2896) 0 (0% of the BN) 40 (57%) 39.7 (56%) 39.7 (57%) 39.7 (57%) 39.8 (57%) 39.8 (57%) Of which BN CaCO3 (mg KOH / g) 51.0 (74% of the BN) 16.9 (24%) 16.9 (24%) 16.9 (23%) 16.0 (23%) 16.9 (24%) 16.9 (24%) Neutralization efficiency index (IE) 100 114 120 117 104 101 118

Claims (17)

1. Cylinder lubricant having a BN determined according to standard ASTM D-2896 greater than or equal to 15, preferably greater than 20, preferably greater than 30, advantageously greater than 40 milligrams of potash per gram of lubricant, comprising:

   a) one or more lubricating base oils for marine engines,

   b) at least one detergent based on alkali or alkaline-earth metals, overbased with metallic carbonate salts, optionally in combination with one or more neutral detergents,

   c) one or more oil-soluble fatty amines having a BN determined according to standard ASTM D-2896 comprised between 150 and 600 milligrams of potash per gram, preferably comprised between 200 and 500 milligrams of potash per gram,

   the percentage by mass of fatty amines relative to the total weight of lubricant being chosen such that the BN provided by these compounds represents a contribution of at least 10 milligrams of potash per gram of lubricant, preferably at least 20 milligrams of potash per gram, preferably at least 30 milligrams of potash per gram, still more preferably at least 40 milligrams of potash per gram of lubricant, to the total BN of said cylinder lubricant,
   the percentage by mass of overbased detergents relative to the total weight of lubricant being chosen such that the BN provided by the metallic carbonate salts represents a contribution of at most 20 milligrams of potash per gram of lubricant to the total BN of said cylinder lubricant, and
   the fatty amine comprises at least one aliphatic chain made up of at least 16 carbon atoms.
2. Cylinder lubricant according to claim 1 in which the percentage by mass of fatty amines relative to the total weight of lubricant is chosen such that the BN provided by these compounds represents at least 15 %, preferably at least 30 %, more preferably at least 50 % of the BN of said cylinder lubricant.
3. Cylinder lubricant according to any one of claims 1 or 2 having a BN determined according to standard ASTM D-2896 comprised between 40 and 80 milligrams of potash per gram of lubricant.
4. Cylinder lubricant according to any one of claims 1 to 3 in which the oil-soluble fatty amine(s) are obtained from palm, olive, peanut, standard or oleic rapeseed, standard or oleic sunflower, soya or cotton oil, from beef tallow, or from palmitic, stearic, oleic or linoleic acid.
5. Cylinder lubricant according to any one of claims 1 to 4 in which the oil-soluble fatty amine(s) are obtained from fatty acids comprising between 16 and 18 carbon atoms.
6. Cylinder lubricant according to any one of claims 1 to 5 in which the fatty amines are polyamines corresponding to the general formula R-[NH-(CH₂)₃]_n-NH₂, where n is an integer comprised between 1 and 3 and R represents the fatty chain of saturated or unsaturated fatty acids comprising at least 16 carbon atoms, preferably the fatty chain of oleic acid.
7. Cylinder lubricant according to any one of claims 1 to 6 in which the fatty amines are diamines corresponding to the general formula R-NH-(CH₂)₃-NH₂, where R represents the fatty chain of saturated or unsaturated fatty acids comprising at least 16 carbon atoms, preferably the fatty chain of oleic acid.
8. Cylinder lubricant according to any one of claims 1 to 7 in which the overbased and/or neutral detergents are chosen from the carboxylates, sulphonates, salicylates, naphthenates, phenates, and mixed detergents combining at least two of these types of detergents.
9. Cylinder lubricant according to any one of claims 1 to 8 in which the overbased and/or neutral detergents are compounds based on metals chosen from the group made up of calcium, magnesium, sodium or barium, preferably calcium or magnesium.
10. Cylinder lubricant according to any one of claims 1 to 9 in which the overbased detergents are overbased by insoluble metallic salts chosen from the group of alkali and alkaline-earth metal carbonates.
11. Cylinder lubricant according to any one of claims 1 to 10 in which the percentage by mass of overbased detergents relative to the total weight of lubricant is chosen such that the BN provided by the metallic carbonate salts represents a contribution of at least 5 milligrams of potash per gram of lubricant, preferably at least 10 milligrams of potash per gram of lubricant to the total BN of said cylinder lubricant.
12. Cylinder lubricant according to any one of claims 1 to 11 in which the percentage by mass of overbased, and optionally neutral, detergents relative to the total weight of lubricant, is chosen such that the organic BN provided by the detergent metallic soaps represents a contribution of at least 5 milligrams of potash per gram of lubricant, preferably at least 10 milligrams of potash per gram of lubricant, in the cylinder lubricants according to the present invention.
13. Cylinder lubricant according to any one of claims 1 to 12, the kinematic viscosity of which, measured according to standard ASTM D445 at 100°C, is comprised between 12.5 and 26.1 cSt, preferably comprised between 16.3 and 21.9 cSt.
14. Cylinder lubricant according to any one of claims 1 to 13 in which one or more base oils are partially or totally replaced by one or more thickening and/or viscosity improving VI polymers.
15. Use of a cylinder lubricant according to any one of claims 1 to 14 as a single cylinder lubricant that can be used both with fuel oils with a sulphur content less than 1.5 % m/m and with fuel oils with a sulphur content greater than 3.5 % m/m.
16. Use of a cylinder lubricant according to any one of claims 1 to 14 as a single cylinder lubricant that can be used both with fuel oils with a sulphur content of less than 1 % m/m and with fuel oils with a sulphur content greater than 3 % m/m.
17. Use of a lubricant according to one of claims 1 to 14 to prevent corrosion and/or reduce the formation of insoluble metallic salt deposits in two-stroke marine engines during the combustion of any type of fuel oil, the sulphur content of which is less than 4.5 % m/m.

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