EP3523407A1

EP3523407A1 - Lubricanting composition for a marine engine or a stationary engine

Info

Publication number: EP3523407A1
Application number: EP17780738.5A
Authority: EP
Inventors: Catherine AMBLARD; Christian Gonneaud
Original assignee: Total Marketing Services SA
Current assignee: TotalEnergies Onetech SAS
Priority date: 2016-10-07
Filing date: 2017-10-06
Publication date: 2019-08-14
Anticipated expiration: 2037-10-06
Also published as: KR102489074B1; KR20190055817A; CN109804053A; TW201823440A; RU2019110090A; JP2019530783A; FR3057273A1; WO2018065606A1; AR109896A1; US11572526B2; JP7041131B2; EP3523407B1; BR112019006244A2; FR3057273B1; US20200040276A1

Abstract

The present invention relates to a lubricating composition comprising: - at least one base oil; - at least one olefin copolymer; - at least one detergent; and - at least one linear hydrogenated styrene/butadiene copolymer. The invention also relates to the use of said composition for reducing fuel consumption in an engine and for enhancing the cleanliness of a 4-stroke or 2-stroke, preferably 4-stroke, marine engine or of a stationary engine.

Description

LUBRICATING COMPOSITION FOR MARINE ENGINE OR STATIONARY ENGINE

The present invention is applicable to the field of lubricating compositions, and more particularly to the field of lubricant compositions for marine engines, in particular for four-stroke or two-stroke marine engines, preferably for four-stroke marine engines, or for stationary engines. More particularly, the present invention relates to lubricant compositions whose use promotes fuel savings (Fuel Eco or FE or Gaz Eco or GE) and having good properties in engine cleanliness, especially cleanliness crankcase. The present invention also relates to a method for reducing the fuel consumption, in particular of fuel oil, of a ship or a plant using this lubricating composition. In the automotive sector, because of environmental concerns, there is a growing interest in reducing emissions and saving fuel. The nature of engine lubricants for automobiles has an influence on these two phenomena, and engine lubricants for automobiles called "fuel-eco" (in English terminology), have emerged. It is mainly the quality of the lubricating bases, alone or in combination with viscosity index improving polymers and / or friction modifying additives, which gives the lubricant its "fuel-eco" properties. The fuel savings generated by "fuel-eco" engine lubricants are essentially achieved during the cold start, when the engine is not yet in stabilized mode, and not at high temperature in stabilized mode. In general, consumption gains in the NEDC (New European Driving Cycle) cycle according to European Directive 70/220 / EEC are cold (urban cycle) of 5%, hot (extra cycle). -1.5%, for average earnings of 2.5%.

But in the field of marine lubricants, marine engines operate at steady state, there are few cold starts. Fuel-eco solutions adapted to automotive engines are therefore not suitable for marine engines. In particular, the gains in consumption obtained in the field of the automobile can not be obtained in the field of the navy.

In addition, the problem of "fuel-eco" is also put forward in the stationary engines of power station. Furthermore, the formulation of a lubricant "fuel-eco" and / or "gas-eco" should not be at the expense of other lubricant performance. In particular, the wear resistance, the demulsification, the neutralization capacity, and the cleanliness of the engine (piston and / or housing) must not be altered.

WO 2007/121039 discloses a lubricating composition comprising a copolymer comprising an olefin block and a vinyl aromatic block and in particular its use to reduce engine fouling. Also known from WO 2013/045648 is a composition comprising at least one copolymer olefin, at least one hydrogenated styrene-isoprene copolymer, at least one glycerol ester and its use to improve the fuel Eco and to limit engine fouling. Finally, WO 2014/135596 discloses a lubricating composition comprising at least one alkoxylated fatty amine and at least one copolymer of styrene and hydrogenated isoprene, and its use to improve the Fuel Eco and to limit the fouling of the engine.

There is therefore an interest in having a lubricating composition for a marine engine or for a stationary engine which allows reductions in the consumption of fuel (fuel and / or gas), in particular fuel, which are satisfactory, while maintaining the other performances of the engine. lubricant composition, in particular the cleanliness of the engine, more specifically the cleanliness of the crankcase.

It is also advantageous to have a lubricating composition for a marine engine or for a stationary engine having good thermal resistance under severe operating conditions, and more particularly in the presence of fuel (fuel and / or gas), particularly fuel. Indeed, during the combustion of the fuel or gas within the engine, residues and unburnt combustion can pollute the lubricant composition and thus alter its thermal behavior and its detergency properties.

An object of the present invention is therefore to provide a lubricant composition overcoming all or in part the aforementioned drawbacks. In particular, it is an object of the present invention to provide a lubricant composition for a marine engine or for a stationary engine that makes it possible to save fuel (fuel oil and / or gas), in particular a gain in Fuel Eco (FE), while maintaining engine cleanliness. .

Another object of the present invention is to provide a lubrication process for saving fuel (fuel and / or gas), including fuel, while maintaining good engine cleanliness. Still other objects will appear on reading the description of the invention which follows.

The subject of the invention is thus a lubricating composition comprising:

at least one base oil;

- at least one detergent;

at least one olefin copolymer; and

at least one linear hydrogenated styrene-butadiene copolymer.

Surprisingly, the Applicant has found that it is possible to formulate lubricant compositions for marine engines or stationary engines to significantly reduce fuel consumption (fuel and / or gas), including fuel (Fuel Eco), while while maintaining or even improving engine cleanliness, including crankcase cleanliness, compared to conventional lubricating compositions for marine engines or for stationary engines. This is made possible by a lubricating composition comprising at least one base oil, at least one detergent, at least one olefin copolymer and at least one linear hydrogenated styrene-butadiene copolymer.

Thus, the present invention makes it possible to formulate lubricating compositions for a 4-stroke or 2-stroke marine engine, preferably 4-stroke, or for a stationary engine, which makes it possible to combine both engine cleanliness and fuel savings (fuel oil and fuel). / or gas), in particular fuel (Fuel Eco).

Advantageously, the lubricant compositions according to the invention have improved thermal resistance under severe conditions, and more particularly in the presence of fuel, in particular fuel.

Advantageously, the lubricant compositions according to the invention have improved storage stability and a viscosity that does not vary or very little over time.

In one embodiment of the invention, the linear hydrogenated styrene / butadiene copolymer may be chosen from hydrogenated styrene / butadiene block copolymers or random hydrogenated styrene / butadiene copolymers, or mixtures thereof. Advantageously, the linear hydrogenated styrene / butadiene copolymer has a content of hydrogenated butadiene units, ranging from 50% to 98% by weight, preferably from 60% to 98%, more preferably from 60% to 90%, relative to to the hydrogenated linear styrene / butadiene copolymer mass.

Advantageously, the hydrogenated linear styrene / butadiene copolymer has a content of hydrogenated butadiene units, ranging from 50% to 98% by moles, preferably from 60% to 98%, more preferably from 70% to 97%, more preferably from 70% to 95%, based on the number of moles of the hydrogenated and linear styrene / butadiene copolymer.

Advantageously, the linear hydrogenated styrene / butadiene copolymer has a content of styrene units, ranging from 2% to 50%, preferably from 2% to 40%, more preferably from 10% to 40% by weight relative to Hydrogenated and linear styrene / butadiene copolymer mass.

Advantageously, the linear hydrogenated styrene / butadiene copolymer has a content of styrene units, ranging from 2% to 50%, preferably from 2% to 40%, more preferably from 5% to 30% by mol relative to the number moles of hydrogenated linear styrene / butadiene copolymer.

In one embodiment of the invention, the linear hydrogenated styrene / butadiene copolymer according to the invention has a weight average molecular weight M _w ranging from 80,000 to 500,000 daltons, preferably from 80,000 to 250,000 daltons. more preferably from 80,000 to 200,000 daltons, still more preferably from 80,000 to 150,000 daltons.

In one embodiment of the invention, the linear hydrogenated styrene / butadiene copolymer according to the invention has a polydispersity index ranging from 0.8 to 1.4, preferably from 0.8 to 1.2.

In one embodiment of the invention, the hydrogenated butadiene units are formed from 5 to 40% by weight of 1,4-butadiene, preferably from 20 to 40% relative to the weight of butadiene units in the copolymer. hydrogenated linear styrene / butadiene and 20 to 60% by weight of butadiene addition 1 -2, preferably 30 to 60% relative to the mass of butadiene units in the hydrogenated linear styrene / butadiene copolymer.

In another embodiment of the invention, the hydrogenated butadiene units are formed from 10 to 60 mol% of butadiene of addition 1 -4, preferably from 20 to 50% with respect to the number of moles of butadiene units in the hydrogenated linear styrene / butadiene copolymer and 30 to 80 mol% of butadiene addition 1 -2, preferably 40 to 60% relative to the number of moles of butadiene units in the hydrogenated styrene / butadiene linear copolymer .

As examples of linear hydrogenated styrene / butadiene copolymer according to the invention, mention may be made of hydrogenated and linear styrene / butadiene polymers marketed by Lubrizol. In one embodiment of the invention, the content by weight of hydrogenated and linear styrene / butadiene copolymer in the lubricating composition according to the invention is from 0.01% to 8% by weight, relative to the total weight of the lubricating composition, preferably from 0.1% to 5%, more preferably from 0.1% to 2%, advantageously from 0.1 to 1%. This amount refers to the amount of active polymer material. Indeed, the linear hydrogenated styrene / butadiene copolymer used in the context of the present invention may be in the form of a dispersion in a mineral or synthetic oil, and more particularly in a Group I oil according to the API classification. Preferably, the olefin copolymer is an ethylene-propylene copolymer.

These copolymer olefins are conventionally copolymers based on ethylene units and propylene units, or optionally copolymers based on ethylene units, propylene units and diene units (EPDM). Preferably, the copolymer olefin according to the invention is an ethylene / propylene copolymer.

The copolymer olefin according to the invention is in linear or star form, preferably in linear form. The olefin copolymer according to the invention is in block form or in statistical form.

The copolymer olefin according to the invention advantageously has a content of ethylene units, ranging from 30% to 80% by weight, relative to the weight of copolymer olefin, preferably from 30% to 70%, more preferably 40% by weight. at 70%. The copolymer olefin according to the invention also advantageously has a content of ethylene units, ranging from 40% to 90% by mole, relative to the number of moles of copolymer olefin, preferably from 40% to 80%, more preferably from 50% to 80%.

The copolymer olefin according to the invention advantageously has a content of propylene units, ranging from 20% to 70% by weight, relative to the weight of copolymer olefin, preferably from 20% to 60%, more preferably 20%. at 50%.

The copolymer olefin according to the invention also advantageously has a content of propylene units, ranging from 10% to 60% by mole, relative to the number of moles of copolymer olefin, preferably from 20% to 60%, more preferably from 20% to 50%.

The copolymer olefin according to the invention advantageously has a weight average molecular weight Mw of between 40,000 and 220,000 daltons, preferably between 60,000 and 220,000 daltons, more preferably between 100,000 and 220,000 daltons, more preferably between 140,000 and 210,000 daltons.

The copolymer olefin according to the invention advantageously has a polydispersity index between 1, 5 and 5, preferably between 2 and 5, more preferably between 2 and 4, even more preferably between 2 and 3.5.

The amount of copolymer olefin in the lubricating composition according to the invention is from 0.01% to 5% by weight, relative to the total weight of the lubricating composition, preferably from 0.01% to 2%, more preferably from 0.01% to 1%, even more preferably from 0.1% to 1%. This quantity is understood as the amount of polymer solids. Indeed, the olefin copolymer used in the context of the present invention is sometimes diluted in a mineral or synthetic oil (most often a Group 1 oil according to API classification).

In one embodiment, the lubricant composition according to the invention may comprise at least one detergent.

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 according to the invention are chosen from the alkali metal or alkaline earth metal salts of carboxylic acids, sulphonates, salicylates, naphthenates, and phenates, taken alone or as a mixture. Detergents are named after the nature of the hydrophobic, carboxylate, sulphonate, salicylate, naphthenate or phenate chain.

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

The detergents used will not be overbased (or neutral) or overbased. Non-overbased or "neutral" detergents are used when the metal salts contain the metal in an approximately stoichiometric amount. We talk about overbased detergents, when the metal is in excess (in an amount greater than the stoichiometric amount). The excess metal providing the overbased detergent character is in the form of metal salts insoluble in the oil. 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 types of detergents. 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.

The preferred detergents are carboxylates, sulphonates and / or phenates, taken alone or in admixture, in particular calcium carboxylates, sulphonates and / or phenates.

The amount of detergent in the lubricating composition according to the invention is from 1% to 30% by weight, relative to the total weight of the lubricating composition, preferably from 1% to 25%, more preferably from 1% to 20% more preferably from 3% to 20%.

Preferably, the amount of detergent in the lubricating composition according to the invention is from 10% to 30%, preferably from 10% to 25%, and more preferably from 10% to 20% by weight relative to the total mass. of said lubricating composition.

The BN (Base Number measured according to ASTM D-2896) of the lubricating compositions according to the present invention is wholly or partly provided by neutral or overbased detergents based on alkali or alkaline earth metals. The BN value of the lubricating compositions according to the present invention, measured according to ASTM D-2896, may vary from 3 to 140 mg of KOH / g, preferably from 3 to 80 mg of KOH / g, more preferably from 4 to 60 mg of KOH / g. The BN value will be chosen according to the conditions of use of the lubricating compositions and in particular according to the sulfur content of the fuel used.

Thus, for heavy fuels with a sulfur content ranging from 0.1% to 3.5% by weight, the BN value of the composition will be between 20 and 80 mg of KOH / g, more preferably between 20 and 65 mg of KOH / g. These compositions are preferably used in 4T marine engines or in stationary engines.

Thus also for heavy fuels with a sulfur content ranging from 0.1% to 3.5% by weight, the BN value of the composition will be between 20 and 140 mg of KOH / g, more preferably between 20 and 100 mg of KOH / g. These compositions are preferably used in 2T marine engines, in particular for cylinder oils.

For gasols with a sulfur content ranging from 0.05% to 2% by weight, the BN value of the composition is between 5 and 30 mg of KOH / g, more preferably between 10 and 20 mg of KOH / g. These compositions are preferably used in 4T marine engines or in stationary engines.

For gases, the BN value of the composition is less than 10 mg KOH / g, more preferably between 2 and 8 mg KOH / g. These compositions are preferably used in 4T marine engines or in stationary engines.

In the following of the present invention, the essential additives, the additives described above, that is to say a) at least one copolymer olefin, b) at least one copolymer of styrene and linear hydrogenated butadiene, c ) at least one detergent as defined above.

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

The mineral or synthetic oils generally used in the marine engine oil application belong to one of the classes defined in the API classification as summarized in the table below. Content Content in Saturated Sulfur Viscosity Index (VI)

Group 1 Mineral oils <90%> 0.03% 80 <VI <120

Group II

> 90% <0.03% 80 <VI <120

Hydrocracked oils

Group III

> 90% <0.03%> 120

Hydroisomerized oils

Group IV Poly-alpha-Olefins (PAO)

Other bases not included in groups 1 to

Group V

IV

The Group I mineral oils can be obtained by distillation of selected naphthenic or paraffinic crudes followed by purification of these distillates by processes such as solvent extraction, solvent or catalytic dewaxing, hydrotreatment or hydrogenation. The inorganic bases of Group I are for example the bases called Neutral Solvent (as for example 150NS, 330NS, 500NS or 600NS) or the Brightstock.

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 poly-alpha olefins, polybutenes, polyisobutenes, alkylbenzenes.

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

In a preferred embodiment of the invention, the lubricating base oil is selected from Group I or Group II base oils, alone or as a mixture.

In one embodiment of the invention, the lubricant composition according to the invention can be characterized by a viscometric grade SAE-20, SAE-30, SAE-40, SAE-50 or SAE-60 according to the SAEJ300 classification, preferably SAE-30 or SAE-40, advantageously SAE-30.

Grade 20 oils have a kinematic viscosity at 100 ° C of between 5.6 and 9.3 cSt. Grade 30 oils have a kinematic viscosity at 100 ° C of between 9.3 and 12.5 cSt. Grade 40 oils have a kinematic viscosity at 100 ° C between 12.5 and 16.3 cSt. Grade 50 oils have a kinematic viscosity at 100 ° C of between 16.3 and 21.9 cSt. Grade 60 oils have a kinematic viscosity at 100 ° C between 21.9 and 26.1 cSt.

Kinematic viscosity is measured according to ASTM D7279 at 100 ° C.

In a preferred embodiment, the lubricant composition according to the invention has a kinematic viscosity measured according to ASTM D7279 at 100 ° C. of between 5.6 and 26.1 cSt, preferably between 9.3 and 21.9 cSt. more preferably between 9.3 and 16.3 cSt.

In one embodiment of the invention, the content by weight of base oil in the lubricating composition according to the invention is from 40% to 95%, preferably from 50% to 95%, more preferably from 60% to 95%, advantageously from 60 to 85% relative to the total weight of the lubricant composition.

In one embodiment, the lubricating composition is not in the form of an emulsion.

In addition to the essential additives as described above, the composition according to the invention may comprise at least one optional additive, especially chosen from those commonly used by those skilled in the art. For example, the optional additive may be selected from dispersant additives, anti-wear additives, antioxidants, friction modifiers, pour point improvers, defoamers, thickeners, fatty amines, and the like. mixtures. These are well known to those skilled in the art.

In one embodiment, the lubricant composition according to the invention may further comprise a dispersant.

Dispersants are well-known additives used in the formulation of lubricating compositions, 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.

In one embodiment of the invention, the dispersant may be selected from succinic acid derivatives. Among the derivatives of succinic acid is meant in the sense of the invention, succinic acid esters or amide esters of succinic acid. Preferably, the dispersant is chosen from compounds comprising at least one succinimide group.

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.

In a preferred embodiment of the invention, the dispersant is selected from borated compounds comprising at least one succinimide group.

In a preferred embodiment of the invention, the dispersant may be chosen from borated compounds comprising at least one substituted succinimide group or borated compounds comprising at least two substituted succinimide groups, the succinimide groups being connectable at their vertex level. carrying a nitrogen atom with a polyamine group.

By substituted succinimide group within the meaning of the present invention is meant a succinimide group of which at least one of the vertices is substituted by a hydrocarbon group comprising from 8 to 400 carbon atoms.

Advantageously, the dispersant is chosen from borated compounds comprising at least one succinimide group substituted with a polyisobutene group.

Advantageously, the dispersant is chosen from borated compounds comprising at least two succinimide groups each substituted by a polyisobutene group. More advantageously, the dispersant is chosen from borated compounds comprising at least two succinimide groups each substituted with a polyisobutene group and characterized by:

A number-average molecular mass of polyisobutene greater than 2000 Daltons, preferably ranging from 2000 to 5000 Daltons, advantageously from 2000 to 3000

daltons,

• A boron element mass content greater than or equal to 0.35% relative to the total mass of the dispersant. The Mannich bases, obtained by polycondensation of phenols substituted with alkyl groups, formaldehyde and primary or secondary amines, can also be used as dispersant in the lubricant composition according to the invention. In one embodiment of the invention, the content by weight of dispersant is at least 0.1%, preferably from 0.1% to 10%, advantageously from 1% to 6% relative to the total weight of the composition. lubricating.

The anti-wear additives protect the friction surfaces by forming a protective film adsorbed on these surfaces. There is a wide variety of anti-wear additives. It is thus possible to mention phospho-sulfur-containing additives, such as metal alkylthiophosphates, in particular zinc alkylthiophosphates, and more specifically zinc dialkyldithiophosphates (or ZnDTPs). The alkyl groups of these zinc dialkyldithiophosphates preferably comprise from 1 to 18 carbon atoms. Amine phosphates, polysulfides, especially sulfur-containing olefins, are also commonly used antiwear additives. Nitrogen-containing and sulfur-containing anti-wear additives, such as, for example, metal dithiocarbamates, in particular molybdenum dithiocarbamates, are also encountered. The preferred anti-wear additive is ZnDTP.

The weight content of anti-wear additive in the lubricant according to the invention is from 0.1% to 5%, preferably from 0.2% to 4%, more preferably from 0.2% to 2% by weight. to the total weight of the lubricating composition.

For example, for pour point improving additives, polymethacrylates (PMA) can be used. The lubricating composition according to the invention may also comprise friction modifiers. Friction modifiers reduce friction between engine parts as much as possible. These additives help prevent engine damage while increasing fuel economy. They can be chosen from organic molecules having a polar function at one of the ends: carboxylic acid and derivatives, glycerol ester, imides, fatty amides, fatty amines and derivatives, phosphoric or phosphonic acid derivatives (phosphite or amine phosphate ). They act by chemical reaction on the metal surface or by absorption on the metal surface (hydrogen bonding).

Another type of friction modifier may be selected from organometallic compounds: molybdenum disthiophosphate, molybdenum dithiocarbamate, copper oleate, copper salicylate.

Finally the friction modifier can be a solid compound: the most common being MoS2 molybdenum disulfide, boron nitride, polytetrafluoroethylene (PTFE). The content by weight of the friction modifier in the lubricant according to the invention is from 0.1% to 5%, preferably from 0.2% to 4%, more preferably from 0.2% to 2% by weight. total of the lubricating composition. The anti-foam additives may be chosen from polar polymers such as polymethylsiloxanes or polyacrylates.

These additives are generally present at a content by weight of 0.01 to 3% relative to the total weight of the lubricating composition. Additives of the lubricating composition may also be chosen from fatty amines and especially from at least one fatty amine of formula (I):

Ri - [(NR ₂₎ -R _3] n-NR ₄ R _'1 5,

in which,

R 1 represents a saturated or unsaturated hydrocarbon group, linear or branched, 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 hydrocarbon group, linear or branched, and optionally comprising at least one heteroatom chosen from nitrogen, sulfur or oxygen, R ₃ represents a saturated or unsaturated hydrocarbon group, linear or branched, comprising one or more carbon atom (s), and optionally comprising at least one heteroatom selected from nitrogen, sulfur or oxygen, preferably oxygen,

N is greater than or equal to 0, preferably n is greater than or equal to 1, more preferably is an integer between 1 and 10, still more preferably between 1 and 6, advantageously is chosen from 1, 2 or 3.

Preferably, the fatty amine may be chosen from mixtures of fatty polyalkylamines comprising one or more polyalkylamines of formulas (II) and / or (III):

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. In one embodiment, the mass percentage of fatty amine is between 1 and 15% relative to the total weight of the lubricating composition, preferably between 1 and 10%. Preferably, the lubricating composition according to the invention comprises:

- 0.01% to 8% by weight of hydrogenated linear styrene / butadiene copolymer, preferably from 0.1% to 5%, more preferably from 0.1% to 2%, advantageously from 0.1 to 1%;

From 0.01% to 5% by weight of copolymer olefin, preferably from 0.01% to 2%, more preferably from 0.01% to 1%, even more preferably from

0.1% to 1%;

1% to 30% by weight of detergent, preferably from 1% to 25%, more preferably from 1% to 20%, even more preferably from 3% to 20%.

Preferably, the lubricating composition according to the invention comprises:

From 0.01% to 5% by weight of copolymer olefin, preferably from 0.01% to 2%, more preferably from 0.01% to 1%, even more preferably from 0.1% to 1%;

10% to 30% by weight of detergent, preferably from 10% to 25%, more preferably from 10% to 20%.

As mentioned above:

the amount of linear hydrogenated styrene / butadiene copolymer is understood as the amount of active polymer material;

the amount of olefin copolymer is understood as the amount of active polymer material.

Advantageously, the lubricant composition according to the invention allows a fuel gain (Fuel Eco and / or Eco Gas) greater than 0.7% at 75% filler, preferably at least 0.8% at 75%. charge, more preferably at least 0.9% to 75% charge. Advantageously, the lubricant composition according to the invention also allows a fuel saving (Fuel Eco and / or Gas Eco) of at least 0.9% to 100% filler, preferably at least 1% to 100%. % of charge. The lubricant composition according to the invention can be advantageously used in marine engines 4-stroke or 2-stroke, preferably 4-stroke, or stationary engines.

In a preferred embodiment, the lubricant composition is used in fast or medium speed 4-stroke engines, which operate respectively with distillates and fuel oils or heavy fuel oil and also with gas. They can also be used as power generation units on large ships or implemented in stationary engines of diesel-electric power plants.

In particular, the lubricant composition is suitable for 4-stroke engines as an oil for piston sheath engine also called TPEO oil.

In particular, the lubricant composition is suitable for 2-stroke engines as a system oil or a cylinder oil. In particular, the lubricant composition is suitable for stationary engines as a piston piston engine oil piston sleeve also called TPEO oil.

Thus, the subject of the invention is also an engine oil for a piston sleeve, also called TPEO (Trunk Piston Engine Oil) oil, comprising a lubricating composition as defined above.

By piston oil piston engine sleeve also called TPEO oil according to the invention, any lubricant composition intended for the lubrication of marine engines 4-stroke or stationary engines, including the housing and cylinders. The invention also relates to a cylinder oil comprising a lubricant composition as defined above.

By cylinder oil according to the invention is meant any lubricating composition for the lubrication of cyclinders of marine engines 2-stroke. The invention also relates to a system oil comprising a lubricating composition as defined above.

By oil system according to the invention is meant any lubricant composition for the lubrication of the lower part of marine engines 2-stroke, including mannetons, the camshaft and palliers of the crankshaft. The system oil also protects the housing and cools the piston heads.

In addition, it also serves as hydraulic fluid.

The invention also relates to the use of a lubricant composition as defined above for the lubrication of marine engines 4-stroke or 2-stroke or stationary engines. In a preferred embodiment, the invention relates to the use of a lubricant composition as defined above for the lubrication of 4-stroke marine engines or stationary engines.

All of the features and preferences presented for the lubricant composition apply to the above use.

The invention also relates to the use of a lubricant composition as defined above for reducing fuel consumption (fuel oil and / or gas), in particular fuel oil, in an engine, in particular 4-stroke marine engines or 2- time or stationary engines, while improving the engine cleanliness, preferably the crankcase cleanliness.

In a preferred embodiment, the invention relates to the use of a lubricant composition as defined above for reducing the fuel consumption, in particular of 4-cycle marine engine fuel or stationary engines, while improving the Engine cleanliness, preferably crankcase cleanliness.

The reduction of the fuel consumption, in particular of fuel oil, is notably evaluated by tests on engine test bench or by evaluation of the tensile coefficient on test machine, in particular on machine MTM (Mini Traction Machine).

Engine cleanliness is notably evaluated by continuous ECBT methods.

The compounds as defined above contained in the lubricant composition according to the invention, and more particularly the olefin copolymer and the hydrogenated styrene / butadiene copolymer may be incorporated into the lubricating composition as separate additives, in particular by separate addition of these in the base oils. However, they can also be integrated in an additive concentrate for marine lubricating composition or stationary engine lubricant composition.

Thus, the subject of the invention is also a composition of concentrated additive type comprising:

at least one detergent,

at least one olefin copolymer,

at least one linear hydrogenated styrene / butadiene copolymer.

All the characteristics and preferences presented for the detergent, the olefin copolymer and the linear hydrogenated styrene / butadiene copolymer also apply to the above composition.

In one embodiment of the invention, at least one base oil can be added to the additive concentrate composition according to the invention to obtain a lubricating composition according to the invention.

Another subject of the invention relates to a method of reducing fuel consumption, in particular fuel oil, and improving engine cleanliness, particularly crankcase cleanliness, comprising contacting the lubricant composition as defined above. or obtained from the concentrate as defined above, with a marine engine or a stationary engine.

The set of characteristics and preferences presented for the lubricant composition or for the additive concentrate type composition also applies to the lubrication process according to the invention.

The various objects of the present invention and their implementations will be better understood on reading the examples which follow. These examples are given for information only, and are not limiting in nature.

Examples

Compositions Ci, C ₂ , L _1; L ₂ and L ₃ are obtained from the following components: The olefin copolymer used in the examples comprises 67 mol% of ethylene units and 33 mol% of propylene units, 58% by weight of ethylene units and 42% by weight of ethylene units. mass of propylene units, and has a mass average molecular weight of between 170,000 Da and 200,000 Da. It exhibits a viscosity at 100 ° C of 4500 cSt when diluted to 7% by mass in a Group 1 oil. The commercial olefin copolymer is diluted 5% by weight in a Group 1 base oil for the compositions and L ₃ .

The commercial olefin copolymer is diluted to 2.3% by weight in a Group 1 base oil for the composition L ₂ .

The hydrogenated and linear styrene-butadiene copolymer used in the examples comprises 82 mol% of hydrogenated butadiene units (of which 32 mol% of 1,4-butadiene addition units and 50 mol% of butadiene addition units 1). -2) and 18 mol% of styrene units, 72% by weight of hydrogenated butadiene units (of which 28% by weight of 1,4-butadiene addition units and 44% by weight of 1,2-addition butadiene units) and 29% by weight of styrene units.

It has a weight average molecular weight of between 120,000 Da and 150,000 Da and has a polydispersity index of between 1 and 1.1. The commercial linear hydrogenated styrene-butadiene copolymer is diluted to 8% by weight in a Group 1 base oil for the compositions L _1; L ₂ and L ₃ .

a detergent package 1 comprising detergents based on calcium carboxylates, calcium phenates, an anti-wear additive, zinc dithiophosphate (ZnDTP), an antifoam and a friction modifier, the package being diluted between 40 and 60% by weight, in a Group 1 base oil,

a detergent package 2 comprising detergents based on calcium carboxylates, calcium phenates, an anti-wear additive, zinc dithiophosphate (ZnDTP), an antifoam, the package being diluted between 40 and 60% by weight in a Group 1 base oil,

Group 2 base oils, in particular bases called 100R and 220R, respectively with viscosities of 4.1 cSt and 6.4 cSt at 100 ° C, and 20.2 cSt and 41.5 cSt at 40 ° C. VS

base oils of group 1, in particular bases called Neutral Solvent 100NS and 150NS, respectively with a viscosity of 4.1 cSt and 5.3 cSt at 100 ° C, and 20.2 cSt and 31.0 cSt at 40 ° C. VS . The composition C ₃ is obtained from the following components:

a styrene / isoprene hydrogenated copolymer (SIH), star-shaped, comprising 90% by weight of hydrogenated isoprene units and 10% by weight of styrene units, with a mass Mw equal to 605,000, with a mass Mn equal to 439,500, of index with a polydispersity of 1, 4, the commercial copolymer is diluted to 10.7% by weight, in a Group 1 base oil,

a linear copolymer olefin (OCP) comprising 50% by mass of ethylene units, with a mass Mw equal to 171,700, with a mass Mn equal to 91,120, with a polydispersity index equal to 1.9, the commercial copolymer is diluted to 12.5% by mass, in a Group 1 base oil,

a package comprising detergents based on calcium carboxylates, calcium sulphonates, and calcium phenates and an anti-wear additive, zinc dithiophosphate (ZnDTP), the package being diluted to 50% by weight, in a Group 1 base oil,

base oils of group 1, in particular bases called Neutral Solvent 150NS and 330NS, respectively viscosity at 40 ° C of 30 cSt and 66 cSt. The percentages of the various constituents are indicated in Tables Ia and Ib below, it is the% by weight of the products used in dilution, and not% by weight of active ingredient.

Example 1 Evaluation of the Thermal Properties of Lubricating Compositions According to the Invention

It is a question of evaluating the thermal resistance of lubricating compositions according to the invention by the implementation of the continuous ECBT test, and thus of simulating engine cleanliness in the presence of such compositions. The following lubricant compositions were tested; the percentages given correspond to mass percentages. Tables la and Ib

Table la

Table Ib

The physico-chemical characteristics of the compositions of Tables Ia and Ib are described in Table II. Table II

The thermal behavior of the compositions was therefore evaluated by means of the continuous ECBT test, by which the mass of deposits (in mg) generated under conditions is measured. determined. The lower the mass, the better the thermal resistance and therefore the better the engine cleanliness.

This test simulates a high temperature engine piston on which the lubricant from the crankcase is sprayed.

The test uses aluminum beakers that simulate the shape of pistons. These beakers were placed in a glass container, kept at controlled temperature by circulating water at 20 ° C. The lubricant was placed in these containers, themselves equipped with a wire brush, partially immersed in the lubricant. This brush was driven in a rotary motion at a speed of 1000 revolutions per minute, which creates a projection of lubricant on the lower surface of the beaker. The beaker was maintained at a temperature of 310 ° C by an electric heating resistor controlled by a thermocouple.

In the continuous ECBT test, the test lasted for 12 hours and the lubricant spray was continuous. This procedure simulates the formation of deposits in the piston-segment assembly. The result is the measured deposit weight 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 by Jean-Philippe ROMAN, MARINE PROPULSION CONFERENCE 2000 - AMSTERDAM - 29-30 MARCH 2000.

The results are summarized in Table III below.

Table III

The results show that the compositions according to the invention have good thermal resistance and thus make it possible to improve engine cleanliness.

It should be noted that the lubricating compositions exhibit improved thermal performance over lubricating compositions comprising an olefin copolymer alone and lubricating compositions comprising an olefin copolymer in combination with a hydrogenated styrene-isoprene copolymer. Example 2 Evaluation of Fuel Economy Properties of Lubricating Compositions According to the Invention

Here, it is a question of determining, by simulation, the properties of economy of consumption of fuel by the use of lubricating compositions according to the invention, by the evaluation of the traction coefficient on machine MTM (Mini Traction Machine) according to the method described below. The tests were carried out on a MTM PCS machine in contact ball 100C6 (standard steel AISI 52100) ultra polished of diameter equal to 19,05mm against flat disk having the same characteristics of material and surface condition than the balls.

The following conditions have been determined for their representativity of the engine operation in the SPC (Piston Segment Shirt) zone, the SPC zone being the zone of the engine in which the majority of the friction takes place and therefore the zone in which the gain in consumption fuel can be maximized:

- load on the 25N ball,

- drive speed of 1 m / s,

- SRR (sliding / rolling ratio) of 100%, this ratio being equivalent to the ratio of sliding speed / rolling speed,

- temperature of 90 ° C.

Thus, under these conditions, the measured tensile coefficient makes it possible to effectively predict the gain in fuel consumption of a lubricating composition; the lower the traction coefficient, the better the consumption of fuel oil.

The compositions were evaluated according to the above method; the results representing the tensile coefficient of each composition are grouped in Table IV.

Table IV

The tensile coefficient for the compositions according to the invention is decreased compared with the comparative compositions Ci and C ₂ .

It is therefore observed that the combination of an olefin copolymer and a linear hydrogenated styrene-butadiene copolymer makes it possible to reduce the coefficient of traction and thus makes it possible to reduce friction. Example 3 Evaluation of Fuel Economy Properties of Lubricating Compositions According to the Invention

The fuel economy properties of the lubricant compositions according to the invention were validated by a test carried out on a bench equipped with a MAN 5L16 / 24 engine. The particular characteristics of this engine have been described in the publication entitled "INNOVATOR-4C, The cuttting-edge MAN B & W 5L16 / 24 test engine", by D. Lançon, V. Doyen and J. Christensen, CIMAC Congress 2004, KYOTO ( Paper 124).

A dedicated steady-state procedure has been developed for measuring the "fuel eco" properties of the lubricant compositions as described below. This procedure uses equipment usually found in engine test centers:

• Rinsing the engine and lubrication circuits with the lubricant candidate,

• Break-in of the engine with the candidate lubricant,

• Measurement of distillate fuel consumption (Marine Diesel Oil - according to specification IS08217). Measurements are repeated to ensure accuracy,

• The fuel consumption obtained with the lubricant candidate is compared with that obtained when a reference lubricant is tested under the same conditions,

• The operating conditions of the engine are:

o Speed: 1000 rpm,

o Power output: 100%, 75% and 25% of maximum power, o Engine lubricant temperature: 68-70 ° C,

o Volume of lubricant: 2 x 200 liters,

• The tests are organized according to a precise protocol which consists of supervising any test carried out with a lubricant candidate between two tests carried out with the reference lubricant. This makes it possible to guarantee the stability of operation of the engine as well as the statistically significant nature of the differences in consumption measured between lubricants.

• In this case, the reference lubricant is a commercial oil for 4T semi-rapid viscosity grade SAE40 and BN 30.

The comparative composition C ₃ and the composition according to the invention were evaluated. The results, representing the gain in fuel consumption for the different engine loads tested, are summarized in Table V. Table V

nd: not determined

It is found that the combination of a hydrogenated linear styrene / butadiene copolymer and a copolymer olefin makes it possible, in the lubricant compositions L _1; L ₂ and L ₃ , to reduce by more than 1% the consumption of fuel oil at 75% of filler but also at 100% relative to the reference oil, unlike the composition C ₃ (comparative) comprising the combination of a hydrogenated styrene / isoprene copolymer and a copolymer olefin which only makes it possible to reduce by 0.7% the fuel oil consumption at 75% of feedstock relative to the reference oil.

In addition, it was observed that the general appearance of the engine and crankcases after the test to demonstrate fuel savings are low fouling, especially with visual ratings of 7.5 out of 10 for crankcase cleanliness and 69.3 out of 100 for piston cleanliness, which is in line with the reference oil, especially 4-stroke marine engines, which also have low fouling, especially with visual ratings of 7.5 out of 10 for cleanliness carter and 69.2 out of 100 for pistons cleanliness. Thus, the above examples show that the lubricant compositions according to the invention have both good thermal behavior, and thus allow to improve the engine cleanliness, while significantly reducing fuel consumption, especially fuel.

Claims

1 .- Lubricating composition comprising:

at least one base oil;

at least one detergent in a content ranging from 10% to 30% by weight relative to the total weight of said lubricating composition;

at least one olefin copolymer;

at least one linear hydrogenated styrene / butadiene copolymer.

2.- lubricating composition according to claim 1 wherein in the hydrogenated styrene / butadiene linear copolymer, the content of hydrogenated butadiene units ranges from 50% to 98% by mole, preferably from 60% to 98%, more preferably 70% by weight; % to 97%, based on the number of moles of hydrogenated linear styrene / butadiene copolymer.

3. - lubricating composition according to claim 1 or 2, wherein the weight content of linear hydrogenated styrene / butadiene copolymer is from 0.01% to 8% by weight, relative to the total weight of the lubricating composition, of preferably from 0.1% to 5%, more preferably from 0.1% to 2%, advantageously from 0.1 to 1%.

4. - lubricating composition according to any one of claims 1 to 3, wherein the olefin copolymer is an ethylene-propylene copolymer.

5. - lubricating composition according to claim 4, wherein the ethylene / propylene copolymer comprises an ethylene content of content ranging from 30% to 80% by weight relative to the weight of copolymer olefin, preferably from 30% to 70% more preferably from 40% to 70%.

6. - lubricating composition according to any one of claims 1 to 5, wherein the amount of olefin copolymer is from 0.01% to 5% by weight, relative to the total weight of the lubricating composition, preferably 0 , 01% to 2%, more preferably from 0.01% to 1%, even more preferably from 0.1% to 1%.

7. A lubricating composition according to any one of claims 1 to 6, wherein the amount of detergents is from 10% to 25% by weight based on the total weight of the lubricating composition, and preferably from 10% to 20% by weight. %.

8. A lubricating composition according to any one of claims 1 to 7, comprising:

0.01% to 8% by weight of linear hydrogenated styrene / butadiene copolymer;

0.01% to 5% by weight of olefin copolymer;

10% to 30% by weight of detergent.

9.- Use of a lubricant composition according to any one of claims 1 to 8 for the lubrication of marine engines 4-stroke or 2-stroke, preferably 4-stroke, or stationary engine.

10.- Use of a lubricant composition according to any one of claims 1 to 8 to reduce fuel consumption while improving marine engine cleanliness 4-stroke or 2-stroke, preferably 4-stroke, or stationary engine .