USE OF A FATAMINE TO PREVENT AND / OR REDUCE METAL LOSS OF PARTS IN AN ENGINE

Description

[0001] The present invention relates to the prevention and / or reduction of metal losses from parts of an engine, in particular a marine engine. More particularly, the present invention relates to the prevention and / or reduction of metal losses from parts of a marine engine due to contact of these parts with an acidic medium.

[0002] The present invention relates to the use of one or more soluble fatty amines in a lubricating composition to prevent and / or reduce metal losses from engine parts, in particular a marine engine.

[0003] The present invention also relates to a method for preventing and / or reducing metal losses from parts of an engine, in particular a marine engine, in which said parts are brought into contact with one or more fatty amines soluble in a lubricating composition.

[0004] The combustion of fuel oils generates the formation of acid gases, in particular sulfur oxides (SO 2 , SO 3 ). These acid gases are, among other things, part of the combustion residues of fuel oils; these residues are in contact with the lubricating oil, and therefore also in contact with the engine parts. Upon contact with the moisture present in the combustion gases and / or in the lubricating oil, these acid gases hydrolyze into sulfurous acid (HSO 3 ) or sulfuric acid (H 2 SO 4 ), which in turn are in contact with the engine parts.

[0005] In the case of marine engines, particularly two-stroke marine engines, lubricating oils are classified into two categories: cylinder oils, which lubricate the piston-cylinder assembly, and system oils, which lubricate all moving parts other than the piston-cylinder assembly. More specifically, it is within the piston-cylinder assembly that combustion residues containing acid gases come into contact with the lubricating oil.

[0006] Generally, the neutralization of these acids is carried out by reaction with the basic sites included in the lubricant. The neutralization capacity of an oil is measured by its BN or Base Number in English, characterizing its basicity. It is measured according to the ASTM D- 2896 standard and is expressed in equivalent weight of potash per gram of oil or mg of KOH / g of oil. The BN is a classic criterion for adjusting the basicity of cylinder oils to the sulfur content of the fuel oil used, in order to be able to neutralize all the sulfur contained in the fuel, and likely to be transformed into sulfuric acid by combustion and hydrolysis. More precisely, marine oils available on the market have a BN varying from 5 to 130 mg KOH / g of oil. This basicity is notably provided by detergents which are overbased by insoluble metal salts, in particular metal carbonates.Detergents, mainly of the anionic type, are for example metallic soaps of the salicylate, phenate, sulfonate, carboxylate type, etc. which form micelles in which the insoluble metallic salt particles are kept in suspension. The usual overbased detergents have an intrinsic BN classically between 150 and 700 mg of potash per gram of detergent.

[0007] Some BN can also be provided by non-overbased or "neutral" detergents with BN typically less than 150 mg of potash per gram of detergent.

[0008] However, the applicant noticed that during the combustion of fuel oil, the neutral and / or overbased detergents present in the lubricating composition deteriorated chemically and consequently formed ash, also called residues or deposits which promoted fouling of the engine, in particular the marine engine.

[0009] In order to reduce the rate of ash formed during the combustion of fuel oil, the applicant replaced part of the detergents providing all of the BN in the lubricating composition with compounds providing BN and forming little or no ash during the combustion of fuel oil. The applicant therefore developed lubricating compositions in which part of the detergents providing the BN in the lubricating composition is replaced by amine compounds.

[0010] WO 2009 / 153453 describes a cylinder lubricating composition having a BN greater than or equal to 40 milligrams of potash per gram of lubricant and comprising a base oil, an alkali metal or alkaline earth metal detergent, overbased with metal carbonate salts, a neutral detergent and a fatty amine and / or oil-soluble fatty amine derivative having a BN of between 150 and 600 milligrams of potash per gram of lubricant.

[0011] WO 2014 / 180843 describes a cylinder lubricating composition having a BN greater than or equal to 50 milligrams of potash per gram of lubricant comprising a base oil, an alkali metal or alkaline earth metal detergent overbased with metal carbonate salts, a neutral detergent and a fatty amine mixture having four amine units.

[0012] EP 2 486 113 describes a marine engine lubricating oil comprising a monoamine comprising a base oil, a detergent and a monoamine disubstituted by a hydrogen atom or a hydrocarbon group having 1 to 50 carbon atoms.

[0013] WO 2011 / 042552 describes a lubricating composition for engines comprising a base oil, a detergent and a monoamine disubstituted by a hydrocarbon group comprising from 1 to 50 carbon atoms and by a hydrogen atom or a hydrocarbon group comprising from 1 to 50 carbon atoms.

[0014] In the continuation of its research, the Applicant surprisingly discovered that the amine compounds, usually used to replace part of the BN in the lubricating composition while reducing the ash content formed during the combustion of fuel oil, also make it possible to prevent and / or reduce metal losses from engine parts, in particular a marine engine, when these are in contact with acids resulting from the combustion of fuel oil.

[0015] Thus, the applicant company noticed that the use of one or more soluble fatty amines in a lubricating composition, the fatty amine being chosen from: compounds of formula (I): R 1 -[(NR 2 )-R 3]m -NR 4 R 5 , in which, R 1 represents a saturated or unsaturated, linear or branched hydrocarbon group, comprising from 12 to 22 carbon atoms, R 2 , R 4 or R 5 independently represents a hydrogen atom; a saturated or unsaturated, linear or branched alkyl group, comprising between 1 and 22 carbon atoms; or a group (R 6 -O) q -H in which R 6 is a saturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, and q represents an integer greater than or equal to 1, R 3 represents a saturated or unsaturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, m is an integer between 1 and 10, more preferably between 1 and 6, even more preferably is chosen from 1, 2 or 3, or a mixture of fatty polyalkylamines comprising one or more polyalkylamines of formulae (III) and / or (IV): in which R, identical or different, represents a linear or branched alkyl group comprising from 8 to 22 carbon atoms, n and z, independently of each other, represent 0, 1, 2 or 3, and when z is greater than 0, o and p, independently of each other, represent 0, 1, 2 or 3, said mixture comprising at least 3% by weight of branched compounds such that at least one of n or z is greater than or equal to 1, or of their derivatives, or mixtures of fatty amines of formulae (I), (III) and / or (IV), helps prevent and / or reduce metal loss from engine parts, preferably a marine engine.

[0016] The fatty amines of formula (I) included in a lubricating composition are known as such in applications WO 2009 / 153453 and WO 2014 / 180843 filed by the applicant. The applicant has now discovered a new use for these fatty amines.

[0017] The present application describes the use of one or more soluble fatty amines in a lubricating composition for preventing and / or reducing metal losses from parts of an engine, preferably a marine engine, the fatty amine being chosen from: the compounds of formula (I): R 1 -[(NR 2 )-R 3]m -NR 4 R 5 , in which, R 1 represents a saturated or unsaturated, linear or branched hydrocarbon group, comprising at least 12 carbon atoms, and optionally at least one heteroatom chosen from nitrogen, sulfur or oxygen, R 2 , R 4 or R 5 independently represents a hydrogen atom or a saturated or unsaturated, linear or branched hydrocarbon group, and optionally comprising at least one heteroatom chosen from nitrogen, sulfur or oxygen, R 3 represents a saturated or unsaturated, linear or branched hydrocarbon group, comprising one or more carbon atom(s), and optionally comprising at least one heteroatom chosen from nitrogen, sulfur or oxygen, preferably oxygen, m is an integer greater than or equal to 1, preferably between 1 and 10, more preferably between 1 and 6, even more preferably is chosen from 1, 2 or 3;or a mixture of fatty dialkyl polyalkylamines comprising one or more polyalkylamines of formulas (III) and / or (IV): ; in which R, identical or different, represents a linear or branched alkyl group comprising from 8 to 22 carbon atoms, n and z represent, independently of each other, 0, 1, 2 or 3, and when z is greater than 0, o and p represent, independently of each other, 0, 1, 2 or 3, said mixture comprising at least 3% by weight of branched compounds such that at least one of n or z is greater than or equal to 1, or of their derivatives; or a mixture of fatty amines of formulae (I), (III) and / or (IV).

[0018] Without being bound by theory, the applicant has surprisingly observed that the fatty amines according to the invention not only make it possible to provide organic BN to the lubricating composition while providing little or no ash during the combustion of fuel oil, but also make it possible to prevent and / or reduce metal losses from engine parts, particularly in a marine engine, when these parts are brought into contact with acids resulting from the combustion of fuel oil. More specifically, the applicant has unexpectedly discovered that these fatty amines, soluble in a lubricating composition in the presence of a large excess of sulfuric acid, make it possible to reduce and / or reduce metal losses from parts directly in contact with said lubricating composition and the large excess of sulfuric acid.This limitation and / or reduction of metal losses from the parts is probably due to the passivation of all or part of the surface of the metal parts by said fatty amines.

[0019] For the purposes of the invention, the term "metal losses from engine parts" means metal losses resulting from the attack of these parts by acids and not metal losses generated by friction of one metal part against another.

[0020] The present invention relates to the use of one or more soluble fatty amines in a lubricating composition for passivating all or part of the surface of metal parts of an engine, preferably a marine engine, and preventing and / or reducing metal losses from said metal parts, the fatty amine is chosen from: Compounds of formula (I): R 1 -[(NR 2 )-R 3]m -NR 4 R 5 , in which, R 1 represents a saturated or unsaturated, linear or branched hydrocarbon group, comprising from 12 to 22 carbon atoms, R 2 , R 4 or R 5 independently represents a hydrogen atom; a saturated or unsaturated, linear or branched alkyl group, comprising between 1 and 22 carbon atoms; or a group (R 6 -O) q -H in which R 6 is a saturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, and q represents an integer greater than or equal to 1, R 3 represents a saturated or unsaturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, m is an integer between 1 and 10, more preferably between 1 and 6, even more preferably is chosen from 1, 2 or 3; or a mixture of one or more polyalkylamines of formulae (III) and / or (IV): in which R, identical or different, represents a linear or branched alkyl group comprising from 8 to 22 carbon atoms, n and z, independently of each other, represent 0, 1, 2 or 3, and when z is greater than 0, o and p, independently of each other, represent 0, 1, 2 or 3, said at least 3% by weight of branched compounds such that at least one of n or z is greater than or equal to 1, or of their derivatives; or a mixture of fatty amines of formulae (I), (III) and / or (IV).

[0021] Preferably, when the fatty amine is of formula (I): R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 12 to 22 carbon atoms, preferably from 14 to 22 carbon atoms, and optionally at least one heteroatom chosen from nitrogen, sulfur or oxygen, and / or R 2 , R 4 or R 5 independently represents a hydrogen atom; a saturated or unsaturated, linear or branched alkyl group comprising between 1 and 22 carbon atoms, preferably between 14 and 22 carbon atoms, more preferably between 16 and 22 carbon atoms;or a group (R 6 -O) q -H in which R 6 is a saturated, linear or branched alkyl group comprising at least 2 carbon atoms, preferably between 2 and 6 carbon atoms, more preferably between 2 and 4 carbon atoms and q represents an integer greater than or equal to 1, preferably between 1 and 6, more preferably between 1 and 4, and / or R 3 represents a saturated or unsaturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, preferably between 2 and 4 carbon atoms. ;

[0022] More preferably, when the fatty amine is of formula (I): m is equal to 1, 2 or 3, R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 12 to 20 carbon atoms, preferably from 14 to 20 carbon atoms, and optionally at least one heteroatom chosen from nitrogen, sulfur or oxygen, R 2 independently represents a hydrogen atom or a saturated, linear or branched alkyl group comprising from 1 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, more preferably from 16 to 18 carbon atoms, R 3 represents a saturated and linear alkyl group comprising between 2 and 6 carbon atoms, preferably between 2 and 4 carbon atoms, R 4 and R 5 represent a hydrogen atom or a methyl group, preferably a hydrogen atom.

[0023] Advantageously, when the fatty amine is of formula (I): m is equal to 3, R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 12 to 20 carbon atoms, preferably from 14 to 20 carbon atoms, more preferably from 16 to 20 carbon atoms, and optionally at least one heteroatom chosen from nitrogen, sulfur or oxygen, R 2 independently represents a hydrogen atom or a saturated, linear or branched alkyl group comprising from 16 to 18 carbon atoms, R 3 represents an ethyl or propyl group, R 4 and R 5 represent a hydrogen atom.

[0024] More preferably, when the fatty amine is also of formula (I): m is equal to 1, 2 or 3, R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 14 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, R 2 , R 4 and R 5 independently represent a hydrogen atom or a group (R 6 -O) q -H in which R 6 is a saturated, linear alkyl group comprising between 2 and 6 carbon atoms, more preferably between 2 and 4 carbon atoms and q representing an integer between 1 and 6, more preferably between 1 and 4, R 3 represents a saturated and linear alkyl group comprising between 2 and 6 carbon atoms, preferably between 2 and 4 carbon atoms.

[0025] Advantageously, when the fatty amine is also of formula (I): m is equal to 3, R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 14 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, R 2 , R 4 and R 5 independently represent a hydrogen atom or a group (R 6 -O) q -H in which R 6 is a saturated, linear alkyl group comprising between 2 and 4 carbon atoms and q representing an integer between 1 and 4, R 3 represents an ethyl or propyl group.

[0026] According to a particular embodiment of the invention, the use of fatty amine of formulas (I), (III) and / or (IV) makes it possible to prevent and / or reduce metal losses from parts in a marine engine, two-stroke or four-stroke during the combustion of any type of fuel oil.

[0027] Preferably, the use of fatty amine of formulas (I), (III) and / or (IV) makes it possible to prevent and / or reduce metal losses from parts in the hot parts, in particular the piston ring-liner (SPC) zone, of a marine engine, two-stroke or four-stroke, during the combustion of any type of fuel oil.

[0028] Preferably, the fuel oil has a sulfur content of less than 3.5% by weight relative to the total weight of the fuel oil. Detailed description of the invention. Fatty amine

[0029] An object of the invention relates to the use of one or more soluble fatty amines in a lubricating composition to prevent and / or reduce metal losses from parts of an engine, preferably a marine engine, the fatty amine is chosen from: compounds of formula (I): R 1 -[(NR 2 )-R 3]m -NR 4 R 5 , in which, R 1 represents a saturated or unsaturated, linear or branched hydrocarbon group, comprising from 12 to 22 carbon atoms, R 2 , R 4 or R 5 independently represents a hydrogen atom; a saturated or unsaturated, linear or branched alkyl group, comprising between 1 and 22 carbon atoms; or a group (R 6 -O) q -H in which R 6 is a saturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, and q represents an integer greater than or equal to 1, R 3 represents a saturated or unsaturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, m is an integer between 1 and 10, more preferably between 1 and 6, even more preferably is chosen from 1, 2 or 3; or a mixture of fatty dialkyl polyalkylamines comprising one or more polyalkylamines of formulae (III) and / or (IV): in which R, identical or different, represents a linear or branched alkyl group comprising from 8 to 22 carbon atoms, n and z represent, independently of each other, 0, 1, 2 or 3, and when z is greater than 0, o and p represent, independently of each other, 0, 1, 2 or 3, said mixture comprising at least 3% by weight of branched compounds such that at least one of n or z is greater than or equal to 1, or of their derivatives; or a mixture of fatty amines of formulae (I), (III) and / or (IV).

[0030] Preferably, another subject of the invention relates to the use of one or more soluble fatty amines in a lubricating composition for preventing and / or reducing metal losses from parts of an engine, preferably a marine engine, the fatty amine is of formula (I): R 1 -[(NR 2 )-R 3]m -NR 4 R 5 , in which, R 1 represents a saturated or unsaturated, linear or branched hydrocarbon group comprising from 12 to 22 carbon atoms, R 2 , R 4 or R 5 independently represents a hydrogen atom; a saturated or unsaturated, linear or branched alkyl group comprising between 1 and 22 carbon atoms; or a group (R 6 -O) q -H in which R 6 is a saturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, and q represents an integer greater than or equal to 1, R 3 represents a saturated or unsaturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, m is an integer between 1 and 10, more preferably between 1 and 6, even more preferably is chosen from 1, 2 or 3.

[0031] Preferably, another subject of the invention relates to the use of one or more soluble fatty amines in a lubricating composition for preventing and / or reducing metal losses from parts of an engine, preferably a marine engine, the fatty amine being a mixture of fatty polyalkylamines comprising one or more polyalkylamines of formulae (III) and / or (IV): in which R, identical or different, represents a linear or branched alkyl group comprising from 8 to 22 carbon atoms, n and z represent, independently of each other, 0, 1, 2 or 3, and when z is greater than 0, o and p represent, independently of each other, 0, 1, 2 or 3, said mixture comprising at least 3% by weight of branched compounds such that at least one of n or z is greater than or equal to 1, or of their derivatives.

[0032] By "fatty amine" according to the invention is meant an amine of formula (I), (III) or (IV) comprising one or more hydrocarbon groups, saturated or unsaturated, linear or branched, and optionally comprising at least one heteroatom chosen from nitrogen, sulfur or oxygen, preferably oxygen.

[0033] By "several fatty amines" according to the invention is meant a mixture of fatty amines of which at least one fatty amine is of formulas (I), (III) and / or (IV).

[0034] Preferably, when the fatty amine is of formula (I): R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 12 to 22 carbon atoms, preferably from 14 to 22 carbon atoms, and / or R 2 , R 4 or R 5 independently represents a hydrogen atom; a saturated or unsaturated, linear or branched alkyl group comprising between 1 and 22 carbon atoms, preferably between 14 and 22 carbon atoms, more preferably between 16 and 22 carbon atoms; or a group (R 6 -O) q -H in which R 6 is a saturated, linear or branched alkyl group comprising between 2 and 4 carbon atoms and q represents an integer greater than or equal to 1, preferably between 1 and 6, more preferably between 1 and 4, and / or R 3 represents a saturated or unsaturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, preferably between 2 and 4 carbon atoms.

[0035] Advantageously, when the fatty amine is of formula (I): m is equal to 1, 2 or 3, R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 14 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, R 2 independently represents a hydrogen atom or a saturated, linear or branched alkyl group comprising from 1 to 20 carbon atoms, more preferably from 16 to 20 carbon atoms, more preferably from 16 to 18 carbon atoms, R 3 represents a saturated and linear alkyl group comprising between 2 and 6 carbon atoms, preferably between 2 and 4 carbon atoms, R 4 and R 5 represent a hydrogen atom or a methyl group, preferably a hydrogen atom.

[0036] In particular, when the fatty amine is of formula (I): m is equal to 3, R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 14 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, R 2 independently represents a hydrogen atom or a saturated, linear or branched alkyl group comprising from 16 to 18 carbon atoms, R 3 represents an ethyl or propyl group, R 4 and R 5 represent a hydrogen atom.

[0037] Advantageously, when the fatty amine is of formula (I): m is equal to 1, 2 or 3, R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 14 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, R 2 , R 4 and R 5 independently represent a hydrogen atom or a group (R 6 -O) q -H in which R 6 is a saturated, linear alkyl group comprising between 2 and 6 carbon atoms, more preferably between 2 and 4 carbon atoms and q representing an integer between 1 and 6, more preferably between 1 and 4, R 3 represents a saturated and linear alkyl group comprising between 2 and 6 carbon atoms, preferably between 2 and 4 carbon atoms.

[0038] In particular, when the fatty amine is of formula (I): m is equal to 3, R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 14 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, R 2 , R 4 and R 5 independently represent a hydrogen atom or a group (R 6 -O) q -H in which R 6 is a saturated, linear alkyl group comprising between 2 and 4 carbon atoms and q representing an integer between 1 and 4, R 3 represents an ethyl or propyl group.

[0039] Generally, the fatty amines of formula (I) according to the invention are mainly obtained from carboxylic acids. These acids are dehydrated in the presence of ammonia to give nitriles, and then undergo catalytic hydrogenation to lead in particular to fatty amines.

[0040] For the purposes of the invention, the fatty amine of formula (I) is obtained from at least one carboxylic acid, preferably at least one fatty acid.

[0041] For the purposes of the invention, the alkyl group of the fatty amine of formula (I) has a number of carbon atoms corresponding to the number of carbon atoms in the carbon chain of the carboxylic acid, preferably corresponding to the number of carbon atoms in the carbon chain of the fatty acid

[0042] For the purposes of the invention, the same fatty amine of formula (I) may be substituted by several alkyl groups obtained from several carboxylic acids, identical or different, preferably obtained from several fatty acids, identical or different.

[0043] According to a particular embodiment of the invention, the alkyl group is obtained from a fatty acid chosen from caprylic, pelargonic, capric, undecylenic, lauric, tridecylenic, myristic, pentadecylic, palmitic, margaric, stearic, nonadecylic, arachic, heneicosanoic, behenic, tricosanoic, lignoceric, pentacosanoic, cerotic, heptacosanoic, montanic, nonacosanoic, melissic, hentriacontanoic, laceroic acids, and their derivatives or unsaturated fatty acids such as palmitoleic, oleic, erucic, nervonic, linoleic, a-linolenic, c-linolenic, di-homo-c-linolenic, arachidonic, eicosapentaenoic, docosahexanoic acids, and their derivatives.

[0044] Preferably, the fatty acids are derived from the hydrolysis of triglycerides present in vegetable and animal oils, such as coconut, palm, olive, peanut, rapeseed, sunflower, soybean, cottonseed, linseed, beef tallow. Natural oils may have been genetically modified to enrich their content of certain fatty acids, for example rapeseed or high oleic sunflower oil.

[0045] Generally, the fatty amine of formula (I) according to the invention is preferably obtained from natural resources, plant or animal. The treatments making it possible to obtain fatty amines from natural oils can lead to mixtures of primary, secondary and tertiary polyamines.

[0046] According to a particular embodiment of the invention, when several fatty amines of formula (I) are used to prevent and / or reduce metal losses from engine parts, said fatty amines form a mixture of fatty amines comprising, in variable proportions, all or part of the compounds corresponding to the following formulas (Ia), (Ib) and (Ic): R 1 -[(NR 2 )-R 3 ]-NR 4 R 5 (Ia), R 1 -[(NR 2 )-R 3 ] 2 -NR 4 R 5 (Ib), R 1 -[(NR 2 )-R 3 ] 3 -NR 4 R 5 (Ic) in which, R 1 represents a saturated or unsaturated, linear or branched hydrocarbon group comprising from 12 to 22 carbon atoms, R 2 , R 4 or R 5 independently represents a hydrogen atom; a saturated or unsaturated, linear or branched alkyl group comprising between 1 and 22 carbon atoms; or a group (R 6 -O) q -H in which R 6 is a saturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, and q represents an integer greater than or equal to 1, R 3 represents a saturated or unsaturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms,

[0047] The preferences and advantages for the definitions of the groups R 1 , R 2 , R 3 , R 4 , R 5 and R 6 of the fatty amines of formulas (Ia), (Ib) and (Ic) are as defined above for the fatty amine of formula (I) according to the invention.

[0048] According to another particular embodiment, the mixture of fatty amines of formula (I) is in a purified form, that is to say comprising mainly a single type of amine of formula (Ia), (Ib) or (Ic), for example mainly diamines of formula (Ia), triamines of formula (Ib) or mainly tetramines of formula (Ic). In particular, the mixture of fatty amines comprises mainly tetramines of formula (Ic).

[0049] According to a particular embodiment of the invention, the mixture of fatty amines of formula (I) mainly comprises: diamines of formula (Ia), or triamines of formula (Ib), or tetramines of formula (Ic), in which, the R groups 1 , R 2 , R 3 , R 4 , R 5 and R 6 are as defined above.

[0050] In another embodiment of the invention, the mixture of fatty amines of formula (I) mainly comprises diamines of formula (Ia) in which: R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 12 to 20 carbon atoms, preferably from 14 to 20 carbon atoms, more preferably from 16 to 20 carbon atoms, R 2 represents a saturated, linear or branched alkyl group comprising from 1 to 5 carbon atoms, preferably from 1 to 3 carbon atoms, more preferably a methyl group, R 3 represents an ethyl or propyl group, R 4 and R 5 independently represent a saturated, linear or branched alkyl group comprising from 1 to 5 carbon atoms, preferably from 1 to 3 carbon atoms, more preferably a methyl group.

[0051] Preferably, the mixture of fatty amines of formula (I) comprises mainly diamines of formula R 1 -[(NR 2 )-R 3] -NH 2 (Ila), triamines of formula R 1 (NR 2 )-R 3 ] 2 -NH 2 (IIb), or tetramines of formula R 1 -[(NR 2 )-R 3 ] 3 -NH 2 (Ilc), in which: R 1 or R 2 represents at least one alkyl group, saturated or unsaturated, obtained from a fatty acid derived from tallow fat, or soybean oil, or coconut oil, or sunflower oil (oleic), and R 3 represents a saturated or unsaturated, linear or branched hydrocarbon group, comprising at least 2 carbon atoms.

[0052] For the purposes of the invention, when R 1 or R 2 represents a saturated alkyl group, said saturated alkyl is obtained from a saturated fatty acid or from an unsaturated fatty acid which has undergone hydrogenation, in particular of all of these double bonds.

[0053] Advantageously, the mixture of fatty amines of formula (I) comprising mainly tetramines of formula R 1 -[(NR 2 )-R 3 ] 3 -NH 2 (IIc) is in the form: of at least one fatty amine of formula (IIc) in which R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 14 to 16 carbon atoms; R 2 represents a hydrogen atom; and R 3 represents a saturated, linear alkyl group comprising from 2 to 6 carbon atoms of at least one fatty amine of formula (IIc) in which R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising at least 18 carbon atoms; R 2 represents a hydrogen atom; and R 3 represents a saturated, linear alkyl group comprising from 2 to 6 carbon atoms, and of at least one fatty amine of formula (IIc) in which R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising at least 20 carbon atoms; R 2 represents a hydrogen atom; and R 3 represents a linear, saturated alkyl group comprising from 2 to 6 carbon atoms.

[0054] In particular, the mixture of fatty amines of formula (I) comprising mainly tetramines of formula R 1 -[(NR 2 )-R 3 ] 3 -NH 2 (IIc) is in the form: of at least one fatty amine of formula (IIc) in which R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 14 to 16 carbon atoms; R 2 represents a hydrogen atom; and R 3 represents a saturated, linear alkyl group comprising from 2 to 6 carbon atoms, of at least one fatty amine of formula (IIc) in which R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising at least 18 carbon atoms; R 2 represents a hydrogen atom; and R 3 represents a saturated, linear alkyl group comprising from 2 to 6 carbon atoms, and of at least one fatty amine of formula (IIc) in which R 1 represents a saturated or unsaturated, linear or branched alkyl group comprising at least 20 carbon atoms; R 2 represents a hydrogen atom; and R 3 represents a linear, saturated alkyl group comprising from 2 to 6 carbon atoms, the sum of the weight content of said fatty amines of formula (IIc) being greater than 90% relative to the weight of said mixture of fatty amines.

[0055] Advantageously, the mixture of fatty amines of formula (I) comprising mainly tetramines of formula R 1 -[(NR 2 )-R 3 ] 3 -NH 2 (Ilc) is also in the form: of at least one fatty amine of formula (IIc) in which R 1 represents a linear or branched unsaturated alkyl group comprising from 16 to 20 carbon atoms, preferably from 18 to 20 carbon atoms; R 2 represents a hydrogen atom; and R 3 represents a linear saturated alkyl group comprising from 2 to 6 carbon atoms and of at least one fatty amine of formula (IIc) in which R 1 represents a linear or branched saturated alkyl group comprising from 16 to 20 carbon atoms, preferably from 18 to 20 carbon atoms; R 2 represents a hydrogen atom; and R 3 represents a linear saturated alkyl group comprising from 2 to 6 carbon atoms.

[0056] In particular, the mixture of fatty amines of formula (I) comprising mainly tetramines of formula R 1 -[(NR 2 )-R 3 ] 3 -NH 2 (IIc) is in the form: of at least one fatty amine of formula (IIc) in which R 1 represents a linear or branched unsaturated alkyl group comprising from 16 to 20 carbon atoms, preferably from 18 to 20 carbon atoms; R 2 represents a hydrogen atom; and R 3 represents a linear saturated alkyl group comprising from 2 to 6 carbon atoms, of at least one fatty amine of formula (IIc) in which R 1 represents a linear or branched saturated alkyl group comprising from 16 to 20 carbon atoms, preferably from 18 to 20 carbon atoms; R 2 represents a hydrogen atom; and R 3 represents a linear saturated alkyl group comprising from 2 to 6 carbon atoms, the sum of the weight content of said fatty amines of formula (IIc) being greater than 90% relative to the weight of said mixture of fatty amines.

[0057] Preferably, the fatty amine mixture of formula (I) does not comprise fatty amines other than fatty amines corresponding to formula (IIc).

[0058] According to a particular embodiment of the invention, when a single fatty amine of formula (I) is used to prevent and / or reduce metal losses from engine parts, said fatty amine corresponds to one of the following formulas: a diamine of formula (IIa), or a triamine of formula (IIb), or a tetramine of formula (IIc), in which, R 1 represents a linear or branched saturated hydrocarbon group, comprising from 14 to 22 carbon atoms, R 2 independently represents a hydrogen atom or a linear or branched saturated hydrocarbon group, comprising between 14 and 22 carbon atoms, R 3 represents a linear saturated hydrocarbon group, comprising between 2 and 6 carbon atoms.

[0059] In this embodiment, the fatty amine of formula (I) is preferably a tetramine of formula (IIc) in which, R 1 represents a linear or branched saturated alkyl group comprising between 14 and 18 carbon atoms, R 2 independently represents a hydrogen atom or a linear or branched saturated hydrocarbon group comprising between 14 and 18 carbon atoms, R 3 represents a linear saturated hydrocarbon group comprising between 2 and 6 carbon atoms.

[0060] In this embodiment, the fatty amine of formula (I) is advantageously a tetramine of formula (IIc) in which, R 1 represents a linear or branched saturated alkyl group, comprising between 16 and 18 carbon atoms, R 2 independently represents a hydrogen atom or a linear or branched saturated hydrocarbon group, comprising between 16 and 18 carbon atoms, R 3 represents an ethyl or propyl group.

[0061] Preferably, when the fatty amine is a mixture of polyalkylamines of formulas (III) and / or (IV), the mixtures of polyalkylamines comprise at least 5% by weight of compounds having a pure linear structure, since these compounds have been shown to have an acceptable viscosity profile.

[0062] According to one embodiment, when the fatty amine is a mixture of polyalkylamines of formulas (III) and / or (IV), the mixtures of polyalkylamines comprise at least 4% by mass (%m / m), preferably at least 5%m / m, preferably at least 6%m / m, preferably more than 7%m / m, preferably more than 7.5%m / m, preferably more than 10%m / m, preferably more than 20%m / m of branched compounds of which at least one of n or z is greater than or equal to 1.

[0063] For products of formula (III), this means that for branched products, n must be greater than or equal to 1.

[0064] Preferably, when the fatty amine is a mixture of polyalkylamines of formulae (III) and / or (IV), when n, o, p or z is equal to 0, the hydrogen atom present at the end of the chain is covalently bonded to the corresponding secondary nitrogen atom.

[0065] Preferably, when the fatty amine is a mixture of polyalkylamines of formulas (III) and / or (IV), the mixture comprises compounds of formulas (III) and / or (IV) in which n, o, p and z, when they are different from 0, are equal to 1 or 2, preferably, when n, o, p and z are different from 0 they are equal to 1.

[0066] According to a preferred embodiment, when the fatty amine is a mixture of polyalkylamines of formulas (III) and / or (IV), the mixture essentially comprises compounds of formulas (III) and / or (IV) for which n, o, p or z independently represent 0, 1 or 2, preferably n, o, p or z independently represent 0 or 1.

[0067] According to a preferred embodiment, when the fatty amine is a mixture of polyalkylamines of formulas (III) and / or (IV), the mixture essentially comprises compounds of formulas (III) and / or (IV) and their derivatives for which n, o, p and z independently represent 0, 1 or 2, preferably, n, o, p and z independently represent 0 or 1.

[0068] Derivatives of compounds of formulas (III) and / or (IV) are described below.

[0069] According to a preferred embodiment, each R group is, independently of one another, an alkyl group, linear or branched, comprising from 14 to 22 carbon atoms, preferably from 14 to 20 carbon atoms, preferably from 16 to 20 carbon atoms.

[0070] Generally, the fatty amines of formula (III) and (IV) according to the invention are mainly obtained from carboxylic acids. These acids are dehydrated in the presence of ammonia to give nitriles, and then undergo catalytic hydrogenation to lead in particular to fatty amines.

[0071] For the purposes of the invention, the fatty amines of formula (III) and (IV) are obtained from at least one carboxylic acid, preferably at least one fatty acid.

[0072] For the purposes of the invention, the alkyl group of the fatty amines of formula (III) and (IV) has a number of carbon atoms corresponding to the number of carbon atoms in the carbon chain of the carboxylic acid, preferably corresponding to the number of carbon atoms in the carbon chain of the fatty acid.

[0073] For the purposes of the invention, the same fatty amine of formula (I) may be substituted by several alkyl groups obtained from several carboxylic acids, identical or different, preferably obtained from several fatty acids, identical or different.

[0074] For the purposes of the invention, the same fatty amine of formula (I) may be substituted by several alkyl groups obtained from several carboxylic acids, identical or different, preferably obtained from several fatty acids, identical or different.

[0075] Although the two R groups may be different, they are, in a preferred embodiment, identical, such compounds being produced more economically. Regardless of whether they are identical or not, one or both R groups, independently, are derived from chemical or natural raw material such as natural oils and fats. In particular, if a natural raw material is used, this means that each R group may have a particular distribution in the length of the carbon chain. Suitably, R is derived from oil or fat of animal or vegetable origin such as tallow, coconut oil and palm oil. Since the preparation of the di-alkyl fatty polyalkylamines according to the invention comprises a hydrogenation step, it may be advantageous, in the process for preparing the products of the invention, to use hydrogenated R groups. Advantageously, the R group is a hydrogenated tallow group.Preferably, the R group of the raw material is unsaturated and is (partially) hydrogenated during the process of preparing the fatty polyalkylamine.

[0076] According to a particular embodiment of the invention, when the fatty amine is a mixture of polyalkylamines of formulae (III) and / or (IV), the alkyl group R is obtained from a fatty acid chosen from caprylic, pelargonic, capric, undecylenic, lauric, tridecylenic, myristic, pentadecylic, palmitic, margaric, stearic, nonadecylic, arachic, heneicosanoic, behenic, tricosanoic, lignoceric, pentacosanoic, cerotic, heptacosanoic, montanic, nonacosanoic, melissic, hentriacontanoic, laceroic acids, and their derivatives or unsaturated fatty acids such as palmitoleic, oleic, erucic, nervonic, linoleic, a-linolenic, c-linolenic, di-homo-c-linolenic acid, arachidonic, eicosapentaenoic, docosahexanoic, and their derivatives.

[0077] Preferably, the fatty acids are derived from the hydrolysis of triglycerides present in vegetable and animal oils, such as coconut, palm, olive, peanut, rapeseed, sunflower, soybean, cottonseed, linseed, beef tallow. Natural oils may have been genetically modified to enrich their content of certain fatty acids, for example rapeseed or high oleic sunflower oil.

[0078] The compositions of fatty dialkyl polyalkylamine derivatives of formulae (III) and / or (IV) according to the invention comprise compounds for which one or more NH moieties of the fatty polyalkylamine of the invention are methylated, alkoxylated, or both. It has been discovered that such compounds possess advantageous solubility, particularly in lubricating oils. Advantageously, the alkoxylated derivatives are butoxylated, propoxylated and / or ethoxylated. If two or more alkoxylating agents are used, they may be used in any order, for example EO-PO-EO, and the different alkoxy units may be polyhedral in nature and / or present randomly. Advantageously, a primary -NH 2 group is alkoxylated with one or more alkylene oxides in a conventional manner to form a -NH-AO-H group, where AO represents one or more alkyleneoxy units.The resulting -NH-AO-H group may be further alkoxylated to form -N(AO-H) 2 units. In particular, when large amounts of alkylene oxide (i.e. more than 8 moles of alkylene oxides per mole of polyalkylamine) are used, generally one or more of the secondary amines, if present, are alkoxylated.

[0079] According to one embodiment, all the primary and secondary amine functions of the di-alkyl polyamine of formulas (III) and / or (IV) are alkoxylated. According to another embodiment, the fatty di-alkyl polyalkylamines are derived by methylation of one or more NH functions in a manner known to those skilled in the art, for example by reaction with formic acid and formaldehyde. According to one embodiment, one or more OH functions of the alkoxylated fatty di-alkyl polyalkylamines are methylated in a conventional manner.

[0080] However, since it may be more economical to prepare mixtures of polyalkylamines of formula (IV), mixtures of polyalkylamines of formula (IV) are preferred. If appropriate, mixtures of polyalkylamines of formulas (III) and / or (IV) are used.

[0081] The branched polyalkylamines of the invention may be produced by any synthetic route known to those skilled in the art. A conventional method of production may be from a diamine and involves two or more cycles, preferably two for economic reasons, each cycle comprising a cyanoethylation step and a hydrogenation step. This process is hereinafter referred to as a two-step process. In an alternative process, one equivalent of di-alkyl diamine may react in a single step with two or more equivalents of acrylonitrile, followed by hydrogenation. In this case, optional additional cycles involving cyanoethylation and hydrogenation steps may be considered. Such a one-step process may be advantageous since it requires fewer intermediate steps. In order to increase branching in the two-step process, an acid catalyst is used such as HCl or acetic acid.Furthermore, increasing the reaction temperature during cyanoethylation also allows for increased branching in this process. When carrying out a multi-cycle process, the temperature of a subsequent cyanoethylation step is higher than the temperature of a previous cyanoethylation step, allowing for the production of a compound with the desired branching. In one embodiment, more than one mole of acrylonitrile per mole of initial polyamine is used, which also allows for increased branching of the expected product to the desired level. Suitably, and in order to maintain a homogeneous reaction mixture, a solvent is used. Preferred solvents include C 1-4 alcohols and C 2-4 diols. Preferably, ethanol is used, as it allows for particular ease of handling.Surprisingly, it has been shown that C 1-4 alcohols and C 2-4 diols are not simple solvents but also possess co-catalytic activity during the cyanoethylation step. The amount of solvent employed can vary over a wide range. For economic reasons, the amount employed is preferably minimal. The amount of solvent, particularly in the cyanoethylation step, is preferably less than 50, 40, 30 or 25% by weight relative to the liquid reaction mixture. The amount of solvent, particularly in the cyanoethylation step, is preferably greater than 0.1, 0.5, 1, 5 or 10% by weight relative to the liquid reaction mixture.

[0082] According to one embodiment, the mixture of fatty di-alkyl polyalkylamines of formulas (III) and / or (IV) according to the invention is characterized by a BN measured according to the ASTM D-2896 standard of between 150 and 350 mg KOH / g of amine, preferably between 170 and 340 and even more preferably between 180 and 320.

[0083] According to one embodiment, in the cylinder lubricants according to the invention, the percentage by weight of the mixture of di-alkyl polyalkylamine relative to the total weight of the lubricating composition is chosen so that the BN provided by these compounds represents a contribution of between 5 and 60 mgKOH / g of lubricant, preferably between 10 and 30 mgKOH / g of lubricant, of the total BN of said cylinder lubricant, measured according to the ASTM D-2896 standard. Lubricating composition

[0084] The fatty amine of formula (I), or the mixture of fatty amines of formulas (III) and / or (IV) or the mixture of fatty amines of formulas (I), (III) and / or (IV) according to the invention for preventing and / or reducing metal losses from parts of an engine, preferably a marine engine, is present in a lubricating composition. Said lubricating composition comprises: at least one base oil, preferably a marine engine lubricating base oil, at least one alkali or alkaline earth metal based detergent, overbased with metal carbonate salts.

[0085] Preferably, the lubricating composition has a BN determined according to the ASTM D-2896 standard greater than or equal to 15 milligrams of potash per gram of lubricant, more preferably greater than or equal to 40 milligrams.

[0086] Advantageously, the lubricating composition has a BN determined according to standard ASTM D-2896 of between 40 and 120 milligrams of potash per gram of lubricant, preferably between 50 and 100 milligrams of potash per gram of lubricant.

[0087] Advantageously, the lubricating composition also has a BN determined according to standard ASTM D-2896 of between 15 and 40 milligrams of potash per gram of lubricant, preferably between 20 and 40 milligrams of potash per gram of lubricant.

[0088] According to one embodiment of the invention, the mass percentage of fatty amine relative to the total weight of the cylinder lubricant is chosen so that the BN provided by this fatty amine represents a contribution of at least 2 milligrams of potash per gram of lubricant to the total BN of said cylinder lubricant, preferably at least 5 milligrams of potash per gram of lubricant to the total BN of said cylinder lubricant.

[0089] The proportion of BN provided by a fatty amine in the cylinder lubricant according to the invention (in milligrams of potash per gram of finished lubricant, or “points” of BN) is calculated from its intrinsic BN measured according to standard ASTM D-2896 and its mass percentage in the finished lubricant: BN amine lub = x . BN amine / 100 BN amine lub = contribution of amine to BN of finished lubricant x = mass % of amine in finished lubricant BN amine = intrinsic BN of amine alone (ASTM D-2896).

[0090] According to one embodiment of the invention, the mass percentage of fatty amine of formulae (I), (III) and / or (IV) relative to the total weight of the cylinder lubricant is chosen so that the BN provided by this fatty amine represents a contribution of 2 to 30 milligrams of potash per gram of lubricant, more preferably of 5 to 25 milligrams of potash per gram of lubricant to the total BN of said cylinder lubricant.

[0091] According to a preferred embodiment of the invention, the fatty amine of formula (I) or the mixture of fatty amines of formulas (III) and / or (IV) or the mixture of fatty amines of formulas (I), (III) and / or (IV) is added in an amount of 0.1 to 15%, preferably 0.5 to 10%, preferably 0.5 to 8% or 3 to 10% by weight relative to the total weight of the lubricating composition.

[0092] In another embodiment of the invention, the fatty amine of formula (I) represents from 0.5 to 10%, preferably from 0.5 to 8% by weight relative to the total weight of the lubricating composition.

[0093] In another embodiment of the invention, the percentage by weight of the mixture of di-alkyl polyalkylamine of formulas (III) and / or (IV) relative to the total weight of lubricant is between 0.1 and 15%, preferably between 0.5 and 10%, advantageously between 3 and 10%.

[0094] Preferably, the lubricating composition further comprises at least one neutral detergent.

[0095] With regard to the detergents used in the lubricating compositions according to the present invention, these are well known to those skilled in the art.

[0096] According to a particular embodiment of the invention, the detergents commonly used in the formulation of lubricating compositions are typically anionic compounds comprising a long lipophilic hydrocarbon chain and a hydrophilic head. The associated cation is typically a metal cation of an alkali or alkaline earth metal.

[0097] The detergents are preferably chosen from alkali or alkaline earth metal salts of carboxylic acids, sulfonates, salicylates, naphthenates, as well as phenate salts.

[0098] The alkali and alkaline earth metals are preferably calcium, magnesium, sodium or barium.

[0099] These metal salts may contain the metal in approximately stoichiometric amounts. In this case, they are referred to as non-overbased or "neutral" detergents, although they also provide some basicity. These "neutral" detergents typically have a BN, measured according to ASTM D2896, of less than 150 mg KOH / g, or less than 100, or even less than 80 mg KOH / g.

[0100] This type of so-called neutral detergents can contribute in part to the BN of the lubricants according to the present invention. For example, neutral detergents of the type carboxylates, sulfonates, salicylates, phenates, naphthenates of alkali and alkaline earth metals, for example calcium, sodium, magnesium, barium, will be used.

[0101] When the metal is in excess (in a quantity greater than the stoichiometric quantity), 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.

[0102] The excess metal providing the overbased character to the detergent is in the form of oil-insoluble metal salts, e.g. carbonate, hydroxide, oxalate, acetate, glutamate, preferably carbonate.

[0103] In the same overbased detergent, the metals in these insoluble salts may be the same as those in oil-soluble detergents or different. They are preferably chosen from calcium, magnesium, sodium or barium.

[0104] Overbased detergents are thus in the form of micelles composed of insoluble metal salts held in suspension in the lubricating composition by the detergents in the form of oil-soluble metal salts.

[0105] These micelles may contain one or more types of insoluble metal salts, stabilized by one or more types of detergent.

[0106] Overbased detergents containing only one type of detergent-soluble metal salt will generally be named after the nature of the hydrophobic chain of the latter detergent.

[0107] Thus, they will be called carboxylate, phenate, salicylate, sulfonate, naphthenate type depending on whether this detergent is respectively a carboxylate, phenate, salicylate, sulfonate, or naphthenate.

[0108] Overbased detergents will be said to be of mixed type if the micelles include several types of detergents, differing from each other by the nature of their hydrophobic chain.

[0109] For use in the lubricating compositions according to the present invention, the oil-soluble metal salts will preferably be carboxylates, phenates, sulfonates of salicylates, and mixed detergents phenate - sulfonate and / or salicylates of calcium, magnesium, sodium or barium.

[0110] The insoluble metal salts providing the overbased character are carbonates of alkali and alkaline earth metals, preferably calcium carbonate.

[0111] The overbased detergents used in the lubricating compositions according to the present invention will preferably be carboxylates, phenates, sulfonates, salicylates and mixed phenate-sulfonate-salicylate detergents, overbased with calcium carbonate.

[0112] According to a particular embodiment of the invention, the base oil included in the lubricating composition is chosen from oils of mineral, synthetic or vegetable origin as well as their mixtures.

[0113] 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 DTP Group 5 Other bases not included in bases groups 1 to 4

[0114] Group 1 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, hydrotreatment or hydrogenation.

[0115] Group 2 and 3 oils are obtained by more severe purification processes, for example a combination of hydrotreating, hydrocracking, hydrogenation and catalytic dewaxing.

[0116] Examples of Group 4 and 5 synthetic bases include polyalpha olefins, polybutenes, polyisobutenes, alkylbenzenes.

[0117] These base oils can be used alone or in a mixture. Mineral oil can be combined with synthetic oil.

[0118] Cylinder oils for 2-stroke marine diesel engines have a viscosity grade of SAE-40 to SAE-60, generally SAE-50 equivalent to a kinematic viscosity at 100°C between 16.3 and 21.9 mm 2 < / s.

[0119] Grade 40 oils have a kinematic viscosity at 100°C between 12.5 and 16.3 mm 2 < / s.

[0120] Grade 50 oils have a kinematic viscosity at 100°C between 16.3 and 21.9 mm 2 < / s.

[0121] Grade 60 oils have a kinematic viscosity at 100°C between 21.9 and 26.1 V.

[0122] According to professional practice, it is preferred to formulate cylinder oils for 2-stroke marine diesel engines with a kinematic viscosity at 100°C of between 18 and 21.5, preferably between 19 and 21.5 mm 2 < / s.

[0123] This viscosity can be achieved by mixing additives and base oils, for example, containing Group 1 mineral bases such as Neutral Solvent bases (e.g. 500NS or 600 NS) and Brightstock. Any other combination of mineral, synthetic or vegetable bases having, when mixed with the additives, a viscosity compatible with the SAE-50 grade can be used.

[0124] Typically, a conventional cylinder lubricant formulation for slow 2-stroke marine diesel engines is of SAE 40 to SAE 60 grade, preferably SAE 50 (according to SAE J300 classification) and comprises at least 50% by weight of lubricating base oil of mineral and / or synthetic origin, suitable for use in marine engines, for example, of API Group 1 class, i.e. obtained by distillation of selected crudes then 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 less than 90%.

[0125] According to a particular embodiment of the invention, the lubricating composition may further comprise one or more thickening additives whose role is to increase the viscosity of the composition, both hot and cold, or viscosity index (VI) improving additives.

[0126] Preferably, these additives are most often low molecular weight polymers, in the order of 2000 to 50,000 daltons (Mn).

[0127] They can be chosen from PIBs (around 2000 daltons), poly-Acrylate or Poly Metacrylates (around 30000 daltons), Olefin-copolymers, Olefin and Alpha Olefin Copolymers, EPDM, Polybutenes, High Molecular Weight Poly-Alphaolefins (viscosity 100°C > 150), Styrene-Olefin Copolymers, hydrogenated or not.

[0128] According to a particular embodiment of the invention, the base oil(s) included in the lubricating composition according to the invention may be partially or totally substituted by these additives.

[0129] Therefore, the polymers used to partially or totally substitute one or more of the base oils are preferably the aforementioned PIB type thickeners (for example marketed under the name Indopol H2100).

[0130] According to a particular embodiment of the invention, the lubricating composition may further comprise at least one anti-wear additive.

[0131] Preferably, the anti-wear additive is zinc dithiophosphate or DTPZn. Also found in this category are various phosphorus, sulfur, nitrogen, chlorine and boron compounds.

[0132] There are a wide variety of anti-wear additives, but the most widely used category is phospho-sulfur additives such as metal alkylthiophosphates, particularly zinc alkylthiophosphates, and more specifically zinc dialkyldithiophosphates or DTPZn.

[0133] Amine phosphates, polysulfides, especially sulfur olefins, are also commonly used anti-wear additives.

[0134] Anti-wear and extreme pressure additives of the nitrogen and sulfur type are also commonly found in lubricating compositions, such as, for example, metal dithiocarbamates, in particular molybdenum dithiocarbamate. Glycerol esters are also anti-wear additives. Examples include mono-, di- and trioleates, monopalmitates and monomyristates.

[0135] According to a particular embodiment of the invention, the lubricating composition may further comprise at least one dispersant.

[0136] Dispersants are well-known additives used in the formulation of lubricating compositions, particularly for applications in the marine sector. Their primary role is to maintain in suspension the particles initially present or appearing in the lubricating composition during its use in the engine. They prevent their agglomeration by acting on steric hindrance. They can also have a synergistic effect on neutralization.

[0137] Dispersants used as lubricant additives typically contain a polar group, associated with a relatively long hydrocarbon chain, generally containing 50 to 400 carbon atoms. The polar group typically contains at least one nitrogen, oxygen, or phosphorus element.

[0138] Compounds derived from succinic acid are dispersants particularly used as lubrication additives. In particular, succinimides, obtained by condensation of succinic anhydrides and amines, and succinic esters obtained by condensation of succinic anhydrides and alcohols or polyols, are used.

[0139] 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.

[0140] Mannich bases, obtained by polycondensation of phenols substituted by alkyl groups, formaldehyde and primary or secondary amines, are also compounds used as dispersants in lubricants.

[0141] A dispersant from the PIB succinimide family, for example borated or zinc-blocked, can be used.

[0142] According to a particular embodiment of the invention, the lubricating composition may further comprise all types of functional additives suitable for their use, for example anti-foam additives to counter the effect of detergents, which may be for example polar polymers such as polymethylsiloxanes, polyacrylates, anti-oxidant and / or anti-rust additives, for example organo-metallic detergents or thiadiazoles. These are known to those skilled in the art.

[0143] According to the present invention, the lubricant compositions 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 an emulsion or a microemulsion. Engine

[0144] The use of one or more fatty amines of formulas (I), (III) and / or (IV) according to the invention soluble in a lubricating composition makes it possible to prevent and / or reduce metal losses from engine parts.

[0145] According to a particular embodiment of the invention, the use of one or more fatty amines of formulae (I), (III) and / or (IV) makes it possible to prevent and / or reduce metal losses from parts in a marine engine, two-stroke or four-stroke during the combustion of any type of fuel oil.

[0146] According to a particular embodiment of the invention, the use of one or more fatty amines of formulae (I), (III) and / or (IV) according to the invention makes it possible to prevent and / or reduce metal losses from parts in the hot parts, in particular the SPC zone, of a marine engine, two-stroke or four-stroke, during the combustion of any type of fuel oil.

[0147] According to a particular embodiment of the invention, the fuel oil has a sulfur content of less than 3.5% by weight relative to the total weight of the fuel oil.

[0148] The various embodiments, variations, preferences and advantages described above may be taken separately or in combination for the implementation of the first object of the invention. Process

[0149] Another object of the invention covers a method for preventing and / or reducing metal losses from parts of an engine, preferably a marine engine, in which said parts are brought into contact with one or more fatty amines soluble in a lubricating composition, the fatty amine being chosen from: compounds of formula (I): R 1 -[(NR 2 )-R 3]m -NR 4 R 5 , in which, R 1 represents a saturated or unsaturated, linear or branched hydrocarbon group, comprising from 12 to 22 carbon atoms, R 2 , R 4 or R 5 independently represents a hydrogen atom; a saturated or unsaturated, linear or branched alkyl group, comprising between 1 and 22 carbon atoms; or a group (R 6 -O) q -H in which R 6 is a saturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, and q represents an integer greater than or equal to 1, R 3 represents a saturated or unsaturated, linear or branched alkyl group comprising between 2 and 6 carbon atoms, m is an integer between 1 and 10, more preferably between 1 and 6, even more preferably is chosen from 1, 2 or 3, a mixture of fatty polyalkylamines comprising one or more polyalkylamines of formulae (III) and / or (IV): in which R, identical or different, represents a linear or branched alkyl group comprising from 8 to 22 carbon atoms, n and z, independently of each other, represent 0, 1, 2 or 3, and when z is greater than 0, o and p, independently of each other, represent 0, 1, 2 or 3, said mixture comprising at least 3% by weight of branched compounds such that at least one of n or z is greater than or equal to 1, or of their derivatives, and a mixture of fatty amines of formulae (I), (III) and / or (IV).

[0150] The different embodiments, preferences, advantages, variants described above covering the use of one or more soluble fatty amines in a lubricating composition to prevent and / or reduce metal losses from parts of an engine, preferably a marine engine, apply separately or in combination to the second subject of the invention covering the method described above.

[0151] The invention is illustrated by the following examples given without limitation. Experimental protocol for measuring metal losses in metal parts

[0152] 200 g of the lubricating composition comprising one or more fatty amines according to the invention are introduced into a 700 mL test tube and this test tube is heated to 60°C with vigorous stirring for a period of approximately 30 minutes.

[0153] A cast iron plate, previously sanded, cleaned and weighed, is immersed in the heated and stirred test tube, then a quantity of 50% diluted sulfuric acid is gradually added over 1 hour 30 minutes so as to neutralize all or part of the total BN in said lubricating composition. The quantity of 50% diluted sulfuric acid added to the lubricating composition is calculated according to the number of BN points to be neutralized. The rate of addition of the 50% diluted sulfuric acid is calculated according to the total quantity of sulfuric acid to be added over a period of 1 hour 30 minutes.

[0154] The lubricating composition thus acidified and comprising the plate is subsequently stirred for a further 30 min to ensure that the BN neutralization reaction is complete.

[0155] The plate immersed in the acidified lubricating composition is then removed from the test piece and weighed in order to determine the metallic losses of said cast iron plate due to attack by the sulfuric acid. EXAMPLE Evaluation of metal losses from a metal part brought into contact with fatty amines according to the invention and with sulfuric acid

[0156] This involves evaluating the metal losses of a metal part directly placed in contact with sulfuric acid and with fatty amines according to the invention contained in a lubricating composition.

[0157] For this purpose, different lubricating compositions were prepared from the following compounds: a lubricating base oil comprising a mixture of group I and / or II mineral oils, in particular Brightstock type oils, a detergent package, a mixture of fatty amines 1 comprising predominantly polyalkylamines of formulas (III) and / or (IV), a fatty amine 2 comprising predominantly tetramines of formula (I), a fatty amine 3 comprising predominantly diamines of formula (I), a fatty amine 4 comprising predominantly triamines of formula (I), a fatty amine 5 comprising predominantly tetramines of formula (I). The compositions L 1 to L 7 according to the invention are described in Table I as well as a control lubricating composition L 8 comprising only a base oil and a detergent package; the percentages indicated correspond to mass percentages.

[0158] The results obtained concerning the metallic losses of the parts brought into contact with sulfuric acid and respectively with the lubricating compositions L 1 to L 8 are described in Table II.

[0159] It is observed that the presence of fatty amines according to the invention contained in compositions L 1 to L 7 and L 9 to L 11 makes it possible to significantly reduce, or even avoid, the metal losses of a part directly brought into contact with sulfuric acid, independently of the content of fatty amines in the lubricating composition, unlike the control composition which does not comprise fatty amines according to the invention. In particular, the metal losses of the parts do not exceed 4 mg when these parts are immersed in an acidic medium and respectively in the presence of different types of fatty amines according to the invention contained in the lubricating compositions, unlike the metal losses of the parts brought into contact with sulfuric acid and a lubricating composition not comprising fatty amines according to the invention which exceed 80 mg.

[0160] It is also a question of evaluating the metallic losses of a metallic part directly brought into contact with fatty amines according to the invention contained in a lubricating composition and with a large excess of sulfuric acid in order to demonstrate that the reduction in metallic losses under such conditions is not due to the neutralization of the sulfuric acid by said fatty amines but indeed comes from the passivation of all or part of the surface of the metallic parts by said fatty amines.

[0161] For this, two metal parts were respectively immersed in the lubricating compositions L 4 and L 8 in the presence of a large excess of sulfuric acid. The results obtained concerning the metal losses of the parts brought into contact with a large excess of sulfuric acid and respectively with the lubricating compositions L 4 and L 8 are described in Table III.

[0162] The test for evaluating the metal losses of a metal part directly brought into contact with fatty amines according to the invention contained in a lubricating composition and with a large excess of sulfuric acid was carried out according to the experimental protocol for measuring the metal losses of metal parts described above. In this test, the quantity of sulfuric acid diluted to 50% introduced into the lubricating composition according to the invention was calculated so as to neutralize 150% of the total BN of the lubricating composition according to Tableau III Compositions L 4 L 8 (witness) Metal losses (mg) 7 117,7

[0163] It is observed that even in the presence of a large excess of sulfuric acid, the metal part loses little material, i.e. it loses 7 mg when it is in contact with fatty amines according to the invention contained in a lubricating composition, unlike a metal part placed in contact with a lubricating composition not comprising fatty amines according to the invention for which the metal losses amount to more than 115 mg.

[0164] Therefore, it is clearly demonstrated that the use of at least one fatty amine and / or fatty amine derivative contained in a lubricating composition makes it possible to significantly reduce, or even avoid, metal losses from a part of an engine, in particular a marine engine, when it is in contact with an acidic environment.

Claims

1. Use of one or more soluble fatty amines in a lubricating composition to passivate all or part of the surface of metal parts of an engine, preferably of a marine engine and prevent and / or reduce the metallic losses of said metal parts, wherein the fatty amine is chosen from among: - the compounds of formula (I):         R1-[(NR2)-R3]m-NR4R5, in which, • R1 represents a saturated or unsaturated hydrocarbon group, linear or branched, comprising from 12 to 22 carbon atoms, • R2, R4 or R5 independently represent a hydrogen atom, a saturated or unsaturated, linear or branched, alkyl group comprising between 1 and 22 carbon atoms or a (R6-O)q-H group wherein R6 is a saturated, linear or branched, alkyl group comprising between 2 and 6 carbon atoms, and q represents an integer greater than or equal to 1, • R3 represents a saturated or unsaturated, linear or branched, alkyl group comprising between 2 and 6 carbon atoms; • m is an integer between 1 and 10, more preferably between 1 and 6, still more preferably selected from among 1, 2 or 3; or - a mixture of one or more polyalkylamines of formulas (III) and / or (IV): in which • R, identical or different, represents a linear or branched alkyl group comprising from 8 to 22 carbon atoms, • n and z, independently of each other, represent 0, 1, 2 or 3, and • o and p represent 0, 1, 2 or 3 independently of each other when z is greater than 0, wherein said mixture comprises at least 3% by weight of branched compounds such as at least one of n or z is greater than or equal to 1, or derivatives thereof; or - a mixture of fatty amines of formulas (I), (III) and / or (IV).

2. Use according to claim 1, wherein: • R1 represents a linear or branched, saturated or unsaturated alkyl group comprising from 14 to 22 carbon atoms, and / or • R2, R4 or R5 independently represent a hydrogen atom; a saturated or unsaturated, linear or branched alkyl group comprising between 14 and 22 carbon atoms, preferably between 16 and 22 carbon atoms; or an (R6-O)q-H group in which R6 is a saturated, linear or branched alkyl group comprising between 2 and 4 carbon atoms, and q represents an integer between 1 and 6, preferably between 1 and 4, and / or • R3 represents a linear or branched, saturated or unsaturated alkyl group comprising between 2 and 4 carbon atoms.

3. Use according to claim 1 or 2, wherein: • m is equal to 1, 2 or 3, • R1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 12 to 20 carbon atoms, preferably from 14 to 20 carbon atoms, • R2 independently represents a hydrogen atom or a saturated, linear or branched alkyl group comprising from 1 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, more preferably from 16 to 18 carbon atoms, • R3 represents a saturated and linear alkyl group comprising between 2 and 6 carbon atoms, preferably between 2 and 4 carbon atoms, • R4 and R5 represent a hydrogen atom or a methyl group, preferably a hydrogen atom.

4. Use according to claim 3, wherein: • m is equal to 3, • R1 represents a saturated or unsaturated, linear or branched alkyl group comprising from 12 to 20 carbon atoms, preferably from 14 to 20 carbon atoms, more preferably from 16 to 20 carbon atoms, • R2 independently represents a hydrogen atom or a linear or branched, saturated alkyl group comprising from 16 to 18 carbon atoms, • R3 represents an ethyl or propyl group, • R4 and R5 represent a hydrogen atom.

5. Use according to claim 1 or 2, wherein: • m is equal to 1, 2 or 3, • R1 represents a linear or branched, saturated or unsaturated alkyl group comprising from 14 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, • R2, R4 or R5 independently represent a hydrogen atom or an (R6-O)q-H group in which R6 is a linear saturated alkyl group comprising between 2 and 6 carbon atoms, more preferably between 2 and 4 carbon atoms; and q represents an integer between 1 and 6, more preferably between 1 and 4, • R3 represents a saturated and linear alkyl group, comprising between 2 and 6 carbon atoms, preferably between 2 and 4 carbon atoms.

6. Use according to claim 5, wherein: • m is equal to 3, • R1 represents a linear or branched, saturated or unsaturated alkyl group comprising from 14 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, • R2, R4 or R5 independently represent a hydrogen atom or an (R6-O)q-H group in which R6 is a linear saturated alkyl group comprising between 2 and 4 carbon atoms and q represents an integer between 1 and 4 , • R3 represents an ethyl or propyl group.

7. Use according to any one of the preceding claims, wherein the mixture of polyalkylamines of formulas (III) and / or (IV) comprises at least 5% by weight of compounds having a pure linear structure.

8. Use according to any one of the preceding claims, wherein the polyalkylamine mixture of formulas (III) and / or (IV) comprises at least 4%, preferably at least 5%, preferably at least 6%, preferably more than 7%, preferably more than 7.5%, preferably more than 10%, preferably more than 20% by weight of branched compounds so that at least n or z is greater than or equal to 1.

9. Use according to any one of the preceding claims, wherein the polyalkylamine mixture of formulas (III) and / or (IV) comprises at least polyalkylamines of formulas (III) and / or (IV) so that when n, o, p and z are not equal to 0, they are equal to 1 or 2, preferably they are equal to 1.

10. Use according to any one of the preceding claims, wherein the polyalkylamine mixture of formulas (III) and / or (IV) comprises at least polyalkylamines of formulas (III) and / or (IV) for which n, o, p or z are independently 0, 1 or 2, preferably independently 0 or 1.

11. Use according to any one of the preceding claims, wherein the polyalkylamine mixture of formulas (III) and / or (IV) comprises at least polyalkylamines of formulas (III) and / or (IV) and their derivatives for which n, o, p or z independently represent 0, 1 or 2, preferably they are independently 0 or 1.

12. Use according to any one of the preceding claims, wherein the mixture of fatty amines of formulas (I), (III) and / or (IV) represents from 0.1 to 15%, preferably from 0.5 to 10%, preferably 0.5 to 8% or 3 to 10% by weight relative to the total weight of the lubricating composition.

13. Use according to any one of the preceding claims for preventing and / or reducing metal losses of parts in a 2-stroke or 4-stroke marine engine, during the combustion of any type of fuel.

14. Use according to any one of the preceding claims, for preventing and / or reducing metal losses of parts in hot parts, including the piston-ring jacket zone, of a 2-stroke or 4-stroke marine engine, during the combustion of any type of fuel.

15. Use according to any one of the preceding claims, wherein the fuel oil has a sulfur content of less than 3.5% by weight relative to the total weight of the fuel oil.