EP2697344B1 - 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 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 milligram equivalent of potash per gram of oil (also referred to as "mg of KOH / g" or "BN point"). 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 IMO (International Maritime Organization) entered into force in May 2005. It sets a maximum sulfur content of 4.5% w / w heavy fuel oils and the creation of Sulfur Emission Control Areas (Sulfur 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 values. specified. 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 maximum sulfur content restrictions become more severe with a maximum global limit of 4.5% m / m to 3.5% m / m by 2012. The Sulfur Emission Control Areas (SECAs) will become ECAs (Emission Control Areas) with a further reduction of the maximum allowable sulfur content from 1.5% m / m to 1.0% m / m by 2010 and the addition of new limits for NOx levels and particles. 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) Maximum sulfur content General limit Limit for ECA's 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 bunk tanks, for a 'high seas' oil to high sulfur content on the one hand and for a fuel 'SECA' with sulfur content less than 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 the lubricant at each change of type of fuel oil.

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 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 where BN is provided in an alternative manner to overbased detergents, by compounds not giving rise to metal deposits when present in excess of the amount of sulfuric acid to be neutralized.

The demand WO 2009/153453 discloses two-cycle marine engine cylinder lubricants for use with both high and low sulfur fuels. The said lubricating compositions have a BN greater than or equal to 15, and comprise one or more lubricating base oils for a marine engine, at least one overbased detergent, optionally in combination with a neutral detergent, one or more oil-soluble fatty amines. . Fatty amines bring at least 10 points of BN, and detergents overbased at most 20 points of BN, to the lubricant.

These lubricating compositions can have a BN of the order of 50 and are as effective from the point of view of acid neutralization kinetics as much higher (typically 70) BN cylinder lubricants, specifically designed for high solids content fuels. sulfur; their reduced rate of overbased detergents also allows them to be adapted to low sulfur content.

However, in this type of composition, a significant part of the BN (at least 10 mg of KOH / g) is provided by the fatty amines. This high level of amine can, for some of them, pose problems of toxicity. This further results in a degradation of the thermal resistance (measured in particular by their ability to form deposits in the ECBT test or "Elf Cokefaction Bench Test" described below).

The antiwear performance of these oils can be further improved. Finally, maintaining the performance of these oils throughout their residence time (about 30 minutes) in the cylinder is problematic.

The demand FR 2094182 discloses a lubricating composition comprising from 0.01 to 5% of an acid neutralization accelerator which may be an ethoxylated fatty diamine, and sufficient alkaline earth metal carbonate to impart a BN of 0.5 to 100 mg KOH / g to the composition. These carbonates can be dispersed in the lubricant by phenates or sulfonates.

In these compositions, almost all BN is provided by alkaline earth metal carbonates. No mention is made of BN shares made respectively by amines, detergents, metal carbonates. No mention is made of the presence of neutral detergents in these compositions.

These compositions have a thermal resistance (measured in particular by their ability to form deposits in the ECBT test) mediocre.

There is therefore a need for two-cycle marine engine cylinder lubricants usable with both high and low sulfur fuels, and whose heat resistance and anti-wear effect is improved over prior art lubricants. .

The present invention relates to a lubricant composition that can be used as cylinder lubricants for two-stroke marine engines, which can be used with both high and low sulfur fuels, and which makes it possible to overcome the disadvantages mentioned above.

Lubricating compositions according to the invention comprise alkoxylated fatty amines in limited amounts, combined with neutral detergents and overbased detergents in specific proportions.

They are as effective from the point of view of acid neutralization kinetics as are much higher (typically 70) BN cylinder lubricants specifically designed for high sulfur fuels; their reduced rate of overbased detergents also allows them to be adapted to low sulfur content fuels.

The compositions according to the invention have very good antiwear properties, and a heat resistance superior to the compositions of the prior art. They are more resistant to aging and retain these properties throughout their residence time in the cylinder of the marine engine.

Description of the invention

1. (a) une ou plusieurs huiles de base lubrifiantes pour moteur marin,
2. (b) au moins un détergent à base de métaux alcalins ou alcalino terreux, surbasé par des sels métalliques de carbonate,
3. (c) au moins un détergent neutre,
4. (d) une ou plusieurs amines grasses alkoxylées solubles dans l'huile, et ayant un BN déterminé selon la norme ASTM D-2896 compris entre 100 et 600 milligrammes de potasse par gramme,

où le pourcentage massique d'amines grasses alkoxylées par rapport au poids total de lubrifiant est choisi de manière à ce que le BN apporté par ces composés représente une contribution comprise entre 2 et 8 milligrammes de potasse par gramme de lubrifiant, et où le BN apporté par les sels métalliques de carbonate représente une contribution d'au plus 65 % du BN total, mesuré selon la norme ASTM D2896, dudit lubrifiant cylindre.The present invention relates to a two-cycle marine engine cylinder lubricant having a BN determined according to ASTM D-2896 greater than or equal to 15 milligrams of potash per gram of lubricant, comprising:

1. (a) one or more lubricating base oils for a marine engine,
2. (b) at least one detergent based on alkali or alkaline earth metals, overbased with carbonate metal salts,
3. (c) at least one neutral detergent,
4. (d) one or more oil-soluble alkoxylated fatty amines having a BN determined according to ASTM D-2896 of between 100 and 600 milligrams of potash per gram,

where the weight percentage of alkoxylated fatty amines relative to the total weight of lubricant is chosen so that the BN supplied by these compounds represents a contribution of between 2 and 8 milligrams of potash per gram of lubricant, and where the BN brought by the carbonate metal salts represents a contribution of at most 65% of the total BN, measured according to ASTM D2896, of said cylinder lubricant.

Preferably, in the cylinder lubricants according to the invention, the BN of the alkoxylated fatty amines determined according to ASTM D-2896 is between 120 and 500, preferably between 150 and 400, preferably between 200 and 300 milligrams of potash per gram.

Preferably, in the cylinder lubricants according to the invention, the weight percentage of alkoxylated fatty amines relative to the total weight of lubricant is chosen so that the BN supplied by these compounds represents a contribution of between 3 and 7 milligrams of potassium hydroxide. per gram of lubricant, preferably between 3.5 and 5 milligrams of potash per gram of total BN lubricant of said cylinder lubricant, determined according to ASTM D-2896.

According to one embodiment, the cylinder lubricants according to the invention have a BN, determined according to ASTM D-2896, greater than or equal to 20, preferably greater than 30, advantageously greater than 40 milligrams of potash per gram of lubricant.

Preferably, the cylinder lubricants according to the invention have a BN, determined according to ASTM D-2896, less than 55 milligrams of potash per gram of lubricant.

According to one embodiment, the cylinder lubricants according to the invention have a BN, determined according to ASTM D-2896, of between 40 and 50 milligrams of potash per gram of lubricant, preferably between 42 and 45 milligrams of potash per gram of lubricant.

According to another embodiment, the cylinder lubricants according to the invention have a BN, determined according to the ASTM D-2896 standard, between 50 and 55 milligrams of potash per gram of lubricant, preferably between 51 and 53 milligrams of potash per gram of lubricant.

Preferably, in the cylinder lubricants according to the invention, the BN supplied by the metal salts of carbonates represents a contribution of between 10% and 60%, preferably between 20% and 55%, preferably between 30% and 50%, of the total BN. said cylinder lubricant.

According to a preferred embodiment, in the cylinder lubricants according to the invention, the oil-soluble alkoxylated fatty amine or amines are obtained from palm, olive, peanut, conventional or oleic rapeseed oil, Classic or oleic sunflower, soya, cotton, from beef tallow, or palmitic, stearic, oleic, linoleic acid.

Preferably, in the cylinder lubricants according to the invention, the oil-soluble alkoxylated fatty amine or amines are obtained from fatty acids comprising between 16 and 18 carbon atoms.

où

• R₁ est un radical éthylène, propylène, butylène, de préférence éthylène,
• R₂ est une chaîne grasse d'acides gras saturé ou insaturé, comprenant entre 12 et 22 atomes de carbone, préférentiellement entre 16 et 18 atomes de carbone, préférentiellement la chaîne grasse de l'acide oléique,
• R₃ est un radical alkylène comprenant entre 2 et 3 atomes de carbone,
• q est égal à 0 ou à 1, et lorsque q est égal à zéro, p est égal à zéro
• n, m et p sont des entiers compris entre 0 et 12, préférentiellement entre 0 et 5, préférentiellement entre 0 et 2
• et n + m + p est strictement supérieur à zéro, préférentiellement compris entre 1 et 15, préférentiellement entre 2 et 10, préférentiellement entre 3 et 7, préférentiellement entre 3 et 4.

Particularly preferably, in the cylinder lubricants according to the invention, the alkoxylated fatty amine (s) correspond to the general formula (I):

or

• R ₁ is an ethylene, propylene or butylene radical, preferably ethylene,
• R ₂ is a fatty chain of saturated or unsaturated fatty acids, comprising between 12 and 22 carbon atoms, preferably between 16 and 18 carbon atoms, preferentially the fatty chain of oleic acid,
• R ₃ is an alkylene radical comprising between 2 and 3 carbon atoms,
• q is 0 or 1, and when q is zero, p is zero
• n, m and p are integers between 0 and 12, preferably between 0 and 5, preferentially between 0 and 2
• and n + m + p is strictly greater than zero, preferably between 1 and 15, preferably between 2 and 10, preferably between 3 and 7, preferentially between 3 and 4.

• q = p = 0
• m + n est compris entre 2 et 5, préférentiellement entre 3 et 4
• m et n sont non nuls

Even more preferentially, in the cylinder lubricants according to the invention, the alkoxylated fatty amine (s) correspond to the general formula (I) in which:

• q = p = 0
• m + n is between 2 and 5, preferably between 3 and 4
• m and n are non-zero

According to one embodiment, in the cylinder lubricants according to the invention, the overbased detergents (b) and the neutral detergents (c) are chosen from carboxylates, sulphonates, salicylates, naphthenates, phenates, and mixed detergents combining at least two of these types of detergents.

According to a preferred embodiment, in the cylinder lubricants according to the invention, at least one overbased detergent (b) is a sulphonate.

According to a particularly preferred embodiment, in the cylinder lubricants according to the invention, at least one neutral detergent (c) is a phenate or a sulphonate, preferably a phenate.

• les monoalcools gras primaires secondaires ou tertiaires, dont la chaîne alkyl est saturée ou insaturée, linéaire ou ramifiée, et comprennent au moins 12 atomes de carbone, préférentiellement entre 12 et 24 atomes de carbone, préférentiellement entre 16 et 18 atomes de carbone, préférentiellement les monoalcools primaires à chaîne alkyl linéaire saturée,
• les esters de monoacides gras saturés comportant au moins 14 atomes de carbone et d'alcools comportant au plus 6 atomes de carbone, préférentiellement les mono et diesters, préférentiellement les monoesters de monoalcool, et les diesters dont les fonctions ester sont distantes au plus de quatre atomes de carbone comptés du côté oxygène de la fonction ester.

According to one embodiment, the cylinder lubricants according to the invention further comprise from 0.1 to 10% by weight, preferably from 0.2 to 2%, preferably from 0.3 to 1.5%, preferentially from 0, 4 to 1%, preferably 0.5 to 1% of one or more compounds selected from:

• primary or secondary tertiary fatty monoalcohols, whose alkyl chain is saturated or unsaturated, linear or branched, and comprise at least 12 carbon atoms, preferably between 12 and 24 carbon atoms, preferably between 16 and 18 carbon atoms, preferably primary monoalcohols with saturated linear alkyl chain,
• saturated fatty acid monoacid esters comprising at least 14 carbon atoms and alcohols containing at most 6 carbon atoms, preferentially mono and diesters, preferentially monoesters of monoalcohol, and diesters whose ester functions are at most four carbon atoms counted on the oxygen side of the ester function.

According to a preferred embodiment, the cylinder lubricants according to the invention have a kinematic viscosity measured according to ASTM D445 at 100 ° C between 12.5 and 26.1 cSt, preferably between 16.3 and 21.9 cSt.

The present invention also relates to the use of a lubricant as described above as a single cylinder lubricant usable both with fuel oils with a sulfur content of less than 1.5% m / m and with fuel oil content in sulfur greater than 3.5% m / m in two-stroke marine engines.

The present invention also relates to the use of a lubricant as described above as a single cylinder lubricant usable with both fuel oils with a sulfur content of less than 1% w / w and with sulfur-containing fuel oils. greater than 3% m / m in two-stroke marine engines.

The present invention also relates to the use of a lubricant as described above as a cylinder lubricant usable with all fuel with a sulfur content of between 0.1% w / w and 3.5% w / w in two-stroke marine engines.

The present invention also relates to the use of a lubricant as described above for preventing corrosion and / or reducing the formation of deposits of insoluble metal salts in the cylinders of two-stroke marine engines during the combustion of any type of fuel oil with a sulfur content of less than 4.5% m / m.

Detailed description of the invention. Alkoxylated fatty amines and other accelerators of neutralization speed:

The fatty amines used in the lubricants according to the present invention are alkoxylated fatty amines, preferably monoamines, or diamines containing one or more aliphatic chains.

These compounds have an intrinsic basicity and contribute to the BN lubricants according to the invention. The intrinsic BN of the alkoxylated fatty amines used in the present invention, measured according to ASTM D-2896, is typically comprised between 100 and 600 milligrams of potash per gram, preferably between 120 and 500 milligrams of potash per gram, preferably between 150 and 400 milligrams of potash per gram, preferably between 200 and 300 milligrams of potash per gram.

These are (weak) surfactants of cationic type, the polar head of which is constituted by the nitrogen atom and by the oxygen atom (s) provided by the alkoxylation, and the lipophilic part by the fatty aliphatic chain (s). . Thus, it is preferable, in order to obtain a surfactant character, for this polar head to consist of amine functions which are not very distant from one another (typically separated by 2 to 3 carbon atoms), and preferably in a restricted number (typically one or two functions). amine), and preferably alkoxylated with a limited number of alkylene oxide functions, typically between 1 and 15, preferably between 2 and 10, preferentially between 3 and 7, preferentially between 3 and 4, and preferably with alkylene oxides comprising from 2 to 4 carbon atoms. This makes it possible to constitute a "compact" polar head, and therefore a surface-active character to these alkoxylated fatty amines.

Because of their (low) surfactant nature and their (strong) lipophilic character, these compounds can both be stabilized in solution in the oil matrix and shift the chemical equilibria within the overbased detergents present in the lubricants according to the invention. . As a result, the basic sites (insoluble metal salts) provided by the overbased detergents are more accessible, which makes the reaction of neutralization of the sulfuric acid by said basic sites more efficient.

The alkoxylated fatty amines are obtained by known alkoxylation processes, for example described in the application FR 2 094 182 , by bringing together the fatty amines and the alkylene oxides, at temperatures for example between 100 and 200 ° C, in the presence of a basic catalyst which may be NaOH, KOH, NaOCH ₃ .

The starting 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, α-linolenic, c-linolenic, di-homo-c-linolenic, 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. The natural oils may have been genetically modified to enrich their content of certain fatty acids, for example rapeseed oil or oleic sunflower oil.

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

For example, it is possible to use, for the preparation of the alkoxylated amines of the lubricants according to the present invention, products containing, in variable proportions, all or part of the fatty amines corresponding to the following formulas:

R ₁ NH ₂ ,

R ₁ -NH-R

R ₁ -NHCH ₂ -R

R ₁ - [NH (CH ₂ ) ₃ ] ₂ -NH ₂

R ₁ - [NH (CH ₂ ) _r ] _q -NH ₂

where q is an integer greater than 1, preferably between 1 and 12, or between 1 and 5, or between 1 and 2, r is an integer between 2 and 3, and R and R ₁ are fatty chains from or fatty acids present in the starting oil. The same mono or fatty polyamine may 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 predominantly monoamines or predominantly diamines.

Advantageously, a product consisting of primary monoamines of formula R ₁ NH _{2 will be used} , where R 1 may represent a plurality of fatty acids derived from a natural resource, for example tallow fat, or soybean oil, or coconut oil, or sunflower oil (oleic).

It is also advantageous to use a product consisting of diamines of formula R ₁ - [NH (CH ₂ ) ₃ ] -NH ₂ , where R ₁ may represent a plurality of fatty acids from a natural resource, for example tallow fat , or soybean oil, or coconut oil, or sunflower oil (oleic).

It is also possible to use purified products. For example, it is advantageous to use amines obtained from oleic acid, in particular primary monoamines of formula R ₁ NH ₂ or diamines of formula R ₁ - [NH (CH ₂ ) ₃ ] -NH ₂ where R ₁ is the fatty chain of oleic acid.

The alkoxylated amines of the lubricants according to the present invention must be highly soluble in the oil matrix in order to be able to effectively increase the acid neutralization kinetics.

Indeed, they act in this respect in two ways: either by directly neutralizing the droplets of dispersed acids in the oil matrix, or by destabilizing the micelles of overbased detergents to increase the effectiveness of the basic sites of said overbased detergents.

où R₁, R₂, R₃ sont tels que définis ci-dessus, n, m, et p sont des entiers non nuls tels que n + m + p est compris entre 1 et 15,
Selon un mode préféré, q = p = 0 et m et n sont des entiers non nuls tels que m + n est compris entre 1 et 5, préférentiellement entre 2 et 4.The solubility of alkoxylated fatty amines is primarily due to their fatty chain. These amines are also all the more soluble that they comprise a limited number of alkylene oxide functions. The Applicant has also found that the alkoxylated amines where the nitrogen atoms are ternary (where no longer NH bond exist) are easier to solubilize, preferentially monoamines with ternary nitrogen.
Thus, it will be preferable to use, in the compositions according to the invention, alkoxylated amines of formula (I) below:

where R ₁ , R ₂ , R ₃ are as defined above, n, m, and p are non-zero integers such that n + m + p is between 1 and 15,
According to a preferred embodiment, q = p = 0 and m and n are non-zero integers such that m + n is between 1 and 5, preferably between 2 and 4.

These alkoxylated amines are therefore all the more effective if they are well dispersed - solubilized in the oil matrix.

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 preferably those which comprise at least one aliphatic chain consisting of at least 12 carbon atoms, preferably at least 14 carbon atoms, preferably at least 16 carbon atoms, preferably at least 18 carbon atoms. carbon.

Surprisingly, the Applicant has found that these alkoxylated amines, and mainly fatty ethoxylated monoamines (preferably of formula (I) above where p = q = 0 and m and n are non-zero integers, preferably such that m + n is between 1 and 5, preferably between 2 and 4) gave remarkable anti-wear properties to the cylinder lubricants which contain them.

However, when they are present in excessive amounts, the thermal properties of the lubricants that contain them are degraded.

Other molecules having a (low) surfactant character and a (strong) lipophilic character may advantageously be used in combination with the alkoxylated fatty amines described above. These compounds increase the rate of acid neutralization by the lubricant.

They can both be stabilized in solution in the oil matrix and shift the chemical equilibria in the overbased detergents present in the lubricants according to the invention. As a result, the basic sites (insoluble metal salts) provided by the overbased detergents are more accessible, which makes the reaction of neutralization of the sulfuric acid by said basic sites more efficient.

These compounds can be used in combination with the alkoxylated amines at contents of between 0.1 and 10% by weight, preferably between 0.1 and 2%, preferably between 0.3 and 1.5%, preferentially between 0.4 and 1.5% by weight. and 1%, preferably between 0.5 and 1%.

It is in particular primary secondary or tertiary fatty monoalcohols, whose alkyl chain is saturated or unsaturated, linear or branched, and comprise at least 12 carbon atoms, preferably between 12 and 24 carbon atoms, preferably from 16 to 18 atoms. of carbon. Preferably, these fatty monoalcohols are primary monoalcohols with a linear saturated alkyl chain, preferably containing from 16 to 18 carbon atoms.

It may also be esters of saturated fatty acids containing at least 14 carbon atoms and alcohols containing at most 6 carbon atoms, preferably chosen from mono and diesters, preferably from monoesters of monoalcohol, and diesters. whose ester functions are at most four carbon atoms from the oxygen side of the ester function.

BN lubricants according to the present invention.

The BN of the lubricants according to the present invention is provided by neutral detergents, overbased detergents based on alkali or alkaline earth metals, and with one or more alkoxylated fatty amines.

The value of this BN, measured according to ASTM D-2896 can vary for a lubricant of 0.5 to 100 mg KOH / g, or beyond.

The BN of a marine engine cylinder lubricant 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 in combination with said 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 two-cycle marine engine cylinder lubricants according to the invention have a BN greater than or equal to 15 milligrams of potash per gram of lubricant, preferably greater than 20, preferably greater than 30, advantageously greater than 40.

According to a preferred embodiment, the cylinder lubricants according to the invention have a BN of less than 55, typically between 40 and 55, preferably between 40 and 50, preferably between 42 and 45, typically of the order of 43 or 44 milligrams of potash per gram of lubricant. This corresponds to the BN of prior art cylinder lubricant formulations specifically used and only with low sulfur fuel oils where (almost) all BN is provided by overbased detergents.

According to another preferred embodiment, the lubricants according to the invention have a BN between 50 and 55, typically between 51 and 53 milligram of potash per gram of lubricant. This corresponds to an intermediate BN between the formulas of the prior art for which the (almost) totality of BN is provided by overbased detergents, specifically used with low-sulfur fuel oils, and those specifically used with high-grade fuel oils. sulfur.

The proportion of BN supplied by the alkoxylated fatty amines in the lubricants according to the invention is between 2 and 8, preferably between 3 and 7, preferably between 3.5 and 5 milligrams of potassium per gram of lubricant (or "BN points"). ").

• 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'aminé seule (ASTM D 28-96).

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).

The intrinsic BN of the alkoxylated amines of the lubricants according to the invention is between 100 and 600, preferably between 120 and 500, preferably between 150 and 400, preferably between 200 and 300.

Thus, in the lubricants according to the invention, the alkoxylated fatty amines provide between 0.33% (supply of 2 points of BN with an amine of BN 600) and 8% (supply of 8 points of BN with an amine of BN 100 ) of the total BN, preferably between 0.4% (contribution of 2 points of BN by an amine of BN 500) and 6.7% (contribution of 8 points of BN by an amine of BN 120) of the total BN, preferably between 0.5% (contribution of 2 points of BN by an amine of BN 400) and 5.3% (contribution of 8 points of BN by an amine of BN 150) of the total BN, preferentially between 0.7% (contribution of 2 BN points with an amine of BN 300) and 4% (contribution of 8 BN points with an amine of BN 200) of the total BN.

Below a certain content of alkoxylated fatty amines, no improvement in the acid neutralization kinetics is obtained.

Moreover, the incorporation of high-grade alkoxylated fatty amines induced a significant drop in viscosity, so that beyond a maximum percentage of alkoxylated fatty amines, it is no longer possible to formulate lubricants. having the viscosity grade required for cylinder lubricant application, except for incorporating 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 alkoxylated amines is also likely to generate toxicity problems.

Moreover, the Applicant has found that the incorporation of high-grade alkoxylated amines results in a degradation of the thermal resistance.

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 and sulphonates, salicylates, and mixed phenate-sulphonate and / or salicylate detergents, preferentially phenates and / or sulphonates. , calcium, magnesium, sodium or barium, preferably calcium phenates and / or sulfonates.

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, preferentially sulphonates and phenates 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 BN supplied by the carbonate metal salts (or BN carbonate or BN _CaCO3 ) 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 brought The carbonate metal salts represent from 50 to 95% of the total BN of the overbased detergent alone.

It should be noted that some neutral detergents also include some content (much less important than overbased detergents) in insoluble metal salts (calcium carbonate), and can themselves contribute to the BN carbonate.

In the lubricants according to the invention, the mass percentage of overbased (and neutral) 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 most 65%. preferably at most 60% of the total BN (according to ASTM D-2896) of said cylinder lubricant.

Indeed, when the contribution of BN carbonate to the total BN of the cylinder lubricant becomes too great, there is a strong degradation of the thermal resistance of the lubricant.

These insoluble metal salts, however, 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, in the lubricants according to the invention, the BN carbonate provided by the insoluble metal salts (calcium carbonate) represent preferably between 10% and 60%, preferably between 20% and 55%, preferably between 30% and 50% of the total BN (ASTM D-2896) of said lubricant.

Thus, for lubricants according to the invention typically having a BN (ASTM D-2896) of the order of 40 to 50, typically of the order of 45 milligrams of potash per gram of lubricant, the BN contribution provided by the Insoluble metal salts of overbased detergents are in the range of 20 to 25 milligrams of potash per gram of lubricant, typically 22 to 24 milligrams of potash per gram of lubricant or "BN point".

On the other hand, the detergents themselves, which are metal soaps of the essentially phenate, or sulfonate, or salicylate type, also contribute to the BN of the lubricants according to the present invention.

1. 1) 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,
2. 2) Le complément de BN, désigné ci après par « BN organique », qui peut être mesuré par différence entre le BN total ASTM D-2896 du lubrifiant et son BN carbonate, et apporté :
   • o par les savons métalliques des détergents surbasés et éventuellement neutres,
   • o par les amines grasses alkoxylées, (ce BN amine étant déterminé en fonction du BN des amines mesuré par ASTM D-2896 et du pourcentage massique d'amines grasses).

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

1. 1) 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,
2. 2) The BN complement, hereinafter referred to as "organic BN", which can be measured by the difference between the total lubricant BN of ASTM D-2896 and its BN carbonate, and provided:
   • o metallic soaps from overbased and possibly neutral detergents,
   • o by the alkoxylated fatty amines, (this BN amine being determined as a function of the BN of the amines measured by ASTM D-2896 and the mass percentage of fatty amines).

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 (VI) Group I Mineral oils <90% > 0.03% 80 ≤ VI <120 Group II Hydrocracked oils ≥ 90% ≤ 0.03% 80 ≤ VI <120 Group III Hydroisomerized Oils ≥ 90% ≤ 0.03% ≥ 120 Group IV PAO (polyalphaolefins) Group V Other bases not included in groups I to IV

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

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

Examples of Group IV and V synthetic bases include polyalphaolefins (PAOs), polybutenes, polyisobutenes, alkylbenzenes.

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

Cylinders 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 16.3 to 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 I mineral bases such as Neutral Solvent (for example 500NS or 600 NS) and Brightstock bases. Any other combination of bases mineral, synthetic or vegetable origin 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 SAE-60, preferably SAE-50 (SA37 J300) and includes at least 50% by weight a lubricating base of mineral and / or synthetic origin, suitable for use in a marine engine, for example, API Group I, 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 1 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 / m ³ ), and 50 to 60% by weight, based on the total weight of lubricant, of a Group I 600 NS base oil (distillate, density at 15 ° C between 880 and 900 kg / m ₃ , viscosity kinematic at 100 ° C close to 12 mm2 / s).

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. In particular, we use 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% by weight of a dispersing additive is used, typically between 0.5 and 2%, typically between 1 and 1.5% by weight of dispersant. For example, it is possible to use a dispersant chosen from the family of PIB succinimides, optionally 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 alkoxylated fatty amines contained in the lubricants according to the present invention may in particular be incorporated in a lubricant as separate additives. However, they can 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 the concentrate, a detergent content greater than 70%, preferably greater than 80%, preferably greater than 90%, a dispersant additive content of 2 to 15%, preferably at 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.

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, advantageously greater than 40 milligrams of potash per gram lubricant, is a concentrate having a BN between 180 and 250, and comprising one or more alkoxylated fatty amines of BN between 100 and 600 mg of potash / g of amine according to ASTM D-2896, the mass percentage of said fatty amines alkoxylated in the concentrate being chosen so as to provide said concentrate a BN contribution determined according to ASTM D-2896 between 10 and 40, preferably between 12 and 30, preferably between 15 and 25, typically of the order 20 milligrams of potash per gram of concentrate.

The alkoxylated fatty amines of the concentrates according to the invention are those described above and in the examples below.

The concentrates may also contain base oil in a small amount (typically between 0 and 5% by weight), but sufficient to facilitate the use of said additive concentrates.

The concentrates are diluted 4 to 5 times in a base oil or in a base oil mixture in order to obtain the cylinder lubricants according to the invention.

A method for preparing the cylinder lubricants according to the invention comprises the step of mixing such a concentrate in one or more base oils, preferably of group 1, so that said concentrate represents between 20 and 30% by weight , typically of the order of 25% by weight, in the cylinder lubricant.

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.

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.

BN carbonate, hereinafter referred to as BN _CaCO3, is measured on the finished oil or the overbased detergents alone, according to the following procedure. It is his principle to attack the overbasing, carbonate (of 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 $${\mathrm{P\; CO}}_{}$$$${}_2=\frac{{\mathrm{<figure-callout\; id="2"\; label="nCO"\; filenames="imgf0001.png"\; state="\{\{state\}\}">nCO</figure-callout>}}_2*\mathrm{R}*\mathrm{T}}{\mathrm{V}}*{10}^{-2}$$
  

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). $$T=\mathrm{273}+\sigma \left(°C\right)=\left(°K\right).$$
  
• 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 .

$$m*B\mathrm{NOT}\mathrm{}\mathit{carbonate}=mg\mathrm{}KOH\mathrm{}\mathrm{ed}quiv\mathrm{at}le\mathrm{not}t\mathrm{.}$$

• m = mass of product in grams
• BN carbonate = BN expressed in equivalent KOH for 1g. $\frac{\mathrm{m}*\mathrm{BN\; carbonate\; *}\frac{44}{2*56.1}}{1000}=g$
  
  of CO ₂ released, ie in moles of CO ₂ released: $$\frac{\mathrm{m}*\mathrm{BN\; carbonate}*44*{10}^{-3}}{44*2*56.1}=\mathrm{m}*\mathrm{BN\; carbonate}*0.0089\mathrm{}{10}^{-3}$$
  

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

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

Formula for calculating BN carbonate from CO pressure ₂ .

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

• 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. $$\boxed{\mathrm{BN\; carbonate}=\frac{\mathrm{P\; lue}*\mathrm{0,0001}}{m*\mathrm{0,0089}*{10}^{-3}*\mathrm{8,32}\left(273*\sigma \mathrm{lue}\right)*{10}^{-2}}}$$
  
  $$\boxed{\mathrm{BN\; carbonate}=\frac{\mathrm{P\; lue}}{m*\mathrm{0,0074}*\mathrm{R}*\left(273*\sigma \mathrm{lue}\right)}}$$
  

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). $$T=\mathrm{273}+\sigma \left(°C\right)=\left(°K\right).\sigma =Temp\mathrm{ed}r\mathrm{at}ture\mathrm{}\mathrm{at}mbi\mathrm{at}\mathrm{not}te\mathrm{}\mathit{read}.$$
  
  m = mass of product introduced into the reaction vessel. $$\boxed{\mathrm{BN\; carbonate}=\frac{\mathrm{P\; read}*0.0001}{m*0.0089*{10}^{-3}*8.32\left(273*\sigma \mathrm{read}\right)*{10}^{-2}}}$$
  
  $$\boxed{\mathrm{BN\; carbonate}=\frac{\mathrm{P\; read}}{m*0.0074*\mathrm{R}*\left(273*\sigma \mathrm{read}\right)}}$$
  

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 release 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 thus calculated with respect to the reference oil to which the value of 100 is attributed. This is the ratio between the neutralization reaction times of the reference (S _ref ) and the sample. measured (S _mes ): $$\mathrm{Neutralization\; efficiency\; index}={\mathrm{S}}_{\mathrm{ref}}/{\mathrm{S}}_{\mathrm{my}}\mathrm{<figure-callout\; id="100"\; label="x"\; filenames="imgf0001.png"\; state="\{\{state\}\}">x</figure-callout>}100$$

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 adapted to the measurement of reaction times of the order of 5 to 20 seconds and to the temperature rise measurement of a few tens of degrees to 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 placing the stirring system inside the reactor so that the acid and the lubricant mix well and repeatedly between two tests, stirring 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: Lubricating compositions

• Huiles de base de groupe I, pour conférer un KV100 de l'ordre de 20 cSt et un KV 40 de l'ordre de 225 à 240 cSt aux compositions,
• Détergent phénate neutre,
• Détergent Phénate surbasé,
• Détergent sulfonate surbasé,
• Monoamine oléique éthoxylée,
• Oleyl propylène diamine (non éthoxylée),
• Alcool gras (mélange de monoalcools gras avec chaînes grasses en C16 à C18).

Several lubricating compositions have been prepared from the following compounds:

• Base oils of group I, to confer a KV100 of the order of 20 cSt and a KV 40 of the order of 225 to 240 cSt to the compositions,
• Neutral phenate detergent,
• Phenate detergent overbased,
• Superbased sulfonate detergent,
• Ethoxylated oleic monoamine
• Oleyl propylene diamine (non-ethoxylated),
• Fatty alcohol (mixture of fatty monoalcohols with C16 to C18 fatty chains).

For each of the compositions prepared, the total BN, according to ASTM D-2896, the BN Carbonate, was measured according to the method described in Example 1, the neutralization efficiency index, according to the method described in the example 2.

The anti-wear properties of these compositions were also measured by the Falex wear test (wear measurement in μm): the lower the wear mark, the better the anti-wear properties.

This test uses a Falex brand tribometer with pawn and blocks. The lubricant to be tested is placed in a heated container to the desired temperature. The blocks are placed in the gap of the jaws and the pin fixed on the mandrel. The pion-blocks assembly is immersed in the oil bath. A fixed load (3760 N in our case) is applied on the set pion-blocks through the jaws and a pneumatic cylinder. The pin is rotated at a fixed speed. A distance sensor located on the cylinder permanently measures the gap of the jaws and therefore the wear of the pin and blocks. This wear is recorded and the final wear result reported as a test result.

The thermal resistance of these compositions was also measured by means of the continuous ECBT test, where the mass of deposits (in mg) generated under given conditions is measured. The lower this mass, the better the thermal resistance.

This test simulates both the thermal stability and the detergency of marine lubricants. The test uses aluminum beakers that simulate the shape of pistons. These beakers are placed in a glass container, maintained at a controlled temperature of the order of 60 ° C. The lubricant is placed in these containers, themselves equipped with a wire brush, partially immersed in the lubricant. This brush is rotated at a speed of 1000 rpm, which creates a projection of lubricant on the bottom surface of the beaker. The beaker is maintained at a temperature of 310 ° C by a heating electric resistance, regulated by a thermocouple.

In the procedure applied and called ECBT Continuous, the test has a duration of 12 hours and the projection of lubricant is continuous. This procedure simulates the formation of deposits in the piston-segment assembly. The result is the weight of deposits measured on the beaker.

A detailed description of this test is given in the publication entitled "Research and Development of Marine Lubricants in ELF ANTAR France - The relevance of laboratory tests in simulating field performance" by Jean-Philippe ROMAN, MARINE PROPULSION CONFERENCE 2000 - AMSTERDAM - 29-30 MARCH 2000 .

The compositions B, F, G and H are compositions according to the invention, whose BN is of the order of 43 to 44.

It can be seen that their neutralization efficiency is identical to or even greater than that of the reference, a BN 70 cylinder oil that can be used with fuels having high sulfur contents. Thus, the compositions according to the invention may for example be used as cylinder oil for marine engine 2 times, with fuels whose content is of the order of 4.5% m / m. The reduction of the overbased detergent content (and therefore insoluble metal salts) thus made possible also allows their use as a cylinder oil for marine engine 2 times, with fuels whose content is low, of the order of 1.5% m / m and less.

Compared to compositions A and C, which do not contain an alkoxylated amine, it is found that the wear properties of the compositions according to the invention are greatly improved.

In the compositions D and E, where the contribution of BN by the amines is high (of the order of 10 to 15 points of BN), a deterioration of the thermal resistance is observed with respect to the compositions according to the invention.

In the compositions I, J and K, where the percentage of BN provided by the carbonates is high (of the order of 70% and above), there is also a degradation of the thermal resistance compared to the compositions according to the invention. invention.

Thus, the compositions according to the invention have the advantage of a neutralization efficiency enabling them to be used both with high and low sulfur fuels, while having improved anti-wear and thermal resistance properties. <b> Table 1: Lubricating compositions and properties </ b> AT B C D E F G H I J K Neutral detergents 1.90 1.90 1.90 1.90 1.90 7.70 3.85 5.80 0.00 2.80 0.00 Detergents overbased 13.65 13.65 13.65 13.65 13.65 9.20 11,10 11.40 10 8.60 12.70 Ethoxylated amine *** - 3.00 6.20 9.00 3.00 3.00 3.00 3.00 3.00 3.00 Diamine grasse **** - 3.15 dispersed 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 Defoamers 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Fatty alcohol C1618 0.50 Group I bases 80.21 80.06 77.01 74.21 78.86 80.81 78.56 85.76 84,36 83.06 Total 100 100 100 100 100 100 100 100 100 100 100 BN Total ASTM D-2896 43.8 43.5 43.3 44.2 43.8 44.8 43.4 43.1 BN CaCO ₃ * 26.7 25.7 24.1 25.6 22.4 37.1 32.7 29.5 % BNCaCo ₃ / BNtotal 62% 59% 56% 58% 51% 83% 75% 68% Neutralization efficiency index ** 105 101 103 101 114 100 101 115 Falex Wear (μm) 58 18 55 19 23 19 17 19 ECBT Deposit (mg) 213 167 191 334 148 158 122 334 256 248 * Measured according to the method described in Example 1
** Measured according to the method described in Example 2
*** BN 160
**** BN 320

Example 4

• Un mélange d'huiles de base de groupe I et de groupe II, pour conférer un KV100 de l'ordre de 20cSt et un KV 40 de l'ordre de 225 à 240 cSt à la composition L,
• Un détergent carboxylate neutre (composition M),
• Un mélange de détergents surbasés phénate et carboxylate (composition N),
• Une bis (2-hydroxyéthyl) cocoalkylamine (composition O), dans les proportions du Tableau 2 ci-dessous,
• Les détergents phénates neutres utilisés dans les compositions L, N et O sont les mêmes que ceux utilisés dans l'exemple 3,
• Les détergents surbasés phénates et sulfonate utilisés dans les compositions L, M, O sont les mêmes que ceux utilisés dans l'exemple 3,
• L'amine éthoxylée monoamine oléique utilisée dans les compositions L, M et O est la même que celle utilisée dans l'exemple 3.

Example 3 was repeated under the same experimental conditions but with other lubricating compositions according to the invention. These compositions are prepared from the following compounds:

• A mixture of Group I and Group II base oils, to give a KV100 of the order of 20 cSt and a KV 40 of about 225 to 240 cSt to the composition L,
• A neutral carboxylate detergent (composition M),
• A mixture of phenate and carboxylate overbased detergents (composition N),
• A bis (2-hydroxyethyl) cocoalkylamine (composition O), in the proportions of Table 2 below,
• Neutral phenate detergents used in compositions L, N and O are the same as those used in Example 3,
• The phenate and sulfonate overbased detergents used in the compositions L, M, O are the same as those used in Example 3,
• The ethoxylated oleic monoamine amine used in the compositions L, M and O is the same as that used in Example 3.

It is found that the lubricant compositions L to O according to the invention have a good neutralization efficiency, good anti-wear properties and thermal resistance regardless of the base oil used (composition L), the neutral detergent used (composition M) the overbased detergent used (composition N) or the ethoxylated amine used (composition O). <b> Table 2: Lubricating compositions and properties (continued) </ b> The M NOT O Neutral phenate detergents 5.80 - 5.80 5.80 Neutral carboxylate detergents - 6.20 - - Phenate and sulfonate overbased detergents 11.40 11.40 - 11.40 Phenate and carboxylate overbased detergents - - 11,60 - Ethoxylated ethoxylated monoamine oleic amine *** 3.00 3.00 3.00 - Ethylated amine bis (2-hydroxyethyl) cocoalkylamine **** - - - 2.45 dispersed 1.20 1.20 1.20 1.20 Defoamers 0.04 0.04 0.04 0.04 Group I bases - 78.16 78.36 79.11 Group I and II bases 78.56 - - - Total 100 100 100 100 BN Total ASTM D-2896 43.6 44.2 43.8 43.9 BN CaCO _{3 *} 26.7 27.0 26.7 27.4 % BNCaCo ₃ / BNtotal 61.2 61.1 61.0 62.4 Neutralization efficiency index ** 111 144 123 134 Falex Wear (μm) 28 33 21 27 ECBT Deposit (mg) 121 99 105 103 * Measured according to the method described in Example 1
** Measured according to the method described in Example 2
*** BN 160 mg KOH / g
**** BN 196 mg KOH / g

Claims (14)

1. Cylinder lubricant for two-stroke marine engines having a BN determined according to standard ASTM D-2896 greater than or equal to 15 milligrams of potassium hydroxide per gram of lubricant, comprising:

   (a) one or more lubricant base oils for marine engines,

   (b) at least one detergent based on alkali metals or alkaline earth metals, overbased with metal carbonate salts,

   (c) at least one neutral detergent,

   (d) one or more oil-soluble alkoxylated fatty amines, having a BN determined according to standard ASTM D-2896 between 100 and 600 milligrams of potassium hydroxide per gram,

   where the percentage by weight of alkoxylated fatty amines relative to the total weight of lubricant is selected so that the BN supplied by these compounds represents a contribution between 2 and 8 milligrams of potassium hydroxide per gram of lubricant, and where the BN supplied by the metal carbonate salts represents a contribution of at most 65% of the total BN, measured according to standard ASTM D2896, of said cylinder lubricant, said contribution being calculated according to the method described in the present description (experimental section).
2. Cylinder lubricant according to Claim 1, wherein the BN of the alkoxylated fatty amines determined according to standard ASTM D-2896 is between 120 and 500, preferably between 150 and 400, preferably between 200 and 300 milligrams of potassium hydroxide per gram.
3. Cylinder lubricant according to one of Claims 1 or 2, wherein the percentage by weight of alkoxylated fatty amines relative to the total weight of lubricant is selected so that the BN supplied by these compounds represents a contribution between 3 and 7 milligrams of potassium hydroxide per gram of lubricant, preferably between 3.5 and 5 milligrams of potassium hydroxide per gram of lubricant to the total BN of said cylinder lubricant, determined according to standard ASTM D-2896.
4. Cylinder lubricant according to one of Claims 1 to 3 having a BN, determined according to standard ASTM D-2896, greater than or equal to 20, preferably greater than 30, advantageously greater than 40 milligrams of potassium hydroxide per gram of lubricant.
5. Cylinder lubricant according to one of Claims 1 to 4 having a BN, determined according to standard ASTM D-2896, less than 55 milligrams of potassium hydroxide per gram of lubricant.
6. Cylinder lubricant according to one of Claims 1 to 5, wherein the BN supplied by the metal carbonate salts represents a contribution between 10% and 60%, preferably between 20% and 55%, preferably between 30% and 50%, of the total BN of said cylinder lubricant.
7. Cylinder lubricant according to any one of Claims 1 to 6, wherein the oil-soluble alkoxylated fatty amine or amines are obtained from fatty acids comprising between 16 and 18 carbon atoms.
8. Cylinder lubricant according to any one of Claims 1 to 7, wherein the alkoxylated fatty amine or amines correspond to general formula (I):

   

   where

   R₁ is an ethylene, propylene, or butylene radical, preferably ethylene,

   R₂ is a fatty chain of saturated or unsaturated fatty acids, comprising between 12 and 22 carbon atoms, preferably between 16 and 18 carbon atoms, preferably the fatty chain of oleic acid,

   R₃ is an alkylene radical comprising between 2 and 3 carbon atoms,

   q is equal to 0 or 1, and when q is equal to zero, p is equal to zero

   n, m and p are integers between 0 and 12, preferably between 0 and 5, preferably between 0 and 2

   and n + m + p is strictly greater than zero, preferably between 1 and 15, preferably between 2 and 10, preferably between 3 and 7, preferably between 3 and 4.
9. Cylinder lubricant according to Claim 8, wherein:

   • q=p=0

   • m + n is between 2 and 5, preferably between 3 and 4

   • m and n are not zero.
10. Cylinder lubricant according to any one of Claims 1 to 9, wherein the overbased detergents (b) and the neutral detergents (c) are selected from carboxylates, sulphonates, salicylates, naphthenates, phenolates, and mixed detergents combining at least two of these types of detergents.
11. Cylinder lubricant according to one of Claims 1 to 10, wherein at least one overbased detergent (b) is a sulphonate.
12. Cylinder lubricant according to one of Claims 1 to 11, wherein at least one neutral detergent (c) is a phenolate or a sulphonate, preferably a phenolate.
13. Use of a lubricant according to any one of Claims 1 to 12 as a single cylinder lubricant usable both with fuel oils with a sulphur content below 1.5% w/w and with fuel oils with a sulphur content above 3.5% w/w in two-stroke marine engines.
14. Use of a lubricant according to any one of Claims 1 to 12 as a cylinder lubricant usable with all fuel oils with a sulphur content between 0.1 % w/w and 3.5% w/w in two-stroke marine engines.

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