Spiro compound as a detergent additive in lubricants for engine systems

Abstract

Spiro compound as detergent additive in lubricants intended for powertrain systems The present application relates to the use, as detergent additive in a lubricating composition intended for a powertrain system, of a spiro compound of formula (I) in which M is an atom chosen from boron and aluminum; R represent, independently of one another, a hydrocarbon group comprising from 1 to 50 carbon atoms; and n1 and n2 are, independently of one another, 0, 1 or 2. It also relates to certain compounds of formula (I), a lubricating composition intended for the lubrication of a powertrain system, comprising one or more base oils and at least one spiro compound of formula (I) as well as a method for lubricating a powertrain system using such a composition.

Description

Title of the invention: Spiro compound as detergent additive in lubricants intended for engine systems Technical field

[0001] The present invention relates to the field of lubricating compositions, in particular lubricating compositions for the lubrication of mobile or stationary motorization systems, in particular gasoline, diesel, gas (liquefied, compressed or hydrogen) or dual fuel engines, in particular light and heavy motor vehicles.

[0002] It relates more particularly to the use of specific spiro compounds as detergent additives in lubricating compositions intended for the lubrication of these motorization systems.

[0003] Advantageously, the invention makes it possible to obtain a lubricant having a reduced content of metallic detergents conventionally used in the field of lubricants and, consequently, having a reduced ash content, in particular sulfated ash, while maintaining good detergency properties. Prior art

[0004] Lubricating compositions, also called "lubricants", are commonly used in engines for the main purpose of reducing friction forces between the various moving metal parts in the engines. They are also effective in preventing premature wear or even damage to these parts, and in particular to their surface.

[0005] To do this, a lubricating composition is conventionally composed of a base oil with which several additives are generally associated, such as for example friction modifying additives, dedicated to stimulating the lubricating performance of the base oil, but also to providing additional performance.

[0006] In fact, lubricants intended for the lubrication of engines, for example diesel engines, must meet several requirements. They must therefore combine good anti-wear and anti-corrosion performance, as well as good detergency and dispersion properties to reduce the formation of deposits.

[0007] In particular, it is essential that lubricants, especially for gasoline, diesel, gas (liquefied, compressed or hydrogen) or dual fuel engines, have good detergency properties. In fact, incomplete combustion of the fuel produces soot which can lead to sludge deposits, as well as carbon and varnish deposits. In the case of diesel or gasoline fuels, the residual sulfur in the fuel burns in the combustion chamber to produce sulfur-derived acids. These acids are responsible for corrosion and wear in the engine and accelerate oil degradation.

[0008] Detergent additives are thus added to base oils to prevent the formation of deposits on the surface of metal parts, which are harmful to the engine, by dissolving secondary oxidation and combustion products, and thus increase the engine's service life. The detergent additives commonly used are metal salts, in particular sulfonates, phenates, salicylates of alkali metals, in particular calcium or magnesium, overbased or not.

[0009] However, these metallic detergents generate ash.

[0010] It is known that ash, particularly sulphated ash, as well as phosphorus and sulphur, can damage the exhaust gas post-treatment systems which are now fitted to all new vehicles to eliminate harmful emissions such as NOx, CO or soot.

[0011] However, existing and proposed regulations on environmental emissions require manufacturers to develop increasingly efficient exhaust gas aftertreatment systems. Diesel particulate filters (DPF), for example, which capture particles (PM for "Particle Matter" in English terminology) from the exhaust flow, make it possible to reduce the emissions of exhaust particles from diesel vehicles with a soot filtration efficiency greater than 95%.

[0012] However, when unburned particulate matter, mainly due to sulfated ash (in particular, calcium, magnesium and zinc based), phosphorus and sulfur ("SAPS") is captured by the filter, the pressure drop of the DPF increases because the metallic deposits reduce the porosity of the filter, reducing its permeability and increasing the resistance to the flow of exhaust gases.

[0013] Due to these negative effects on exhaust aftertreatment systems, several OEMs have published guidelines regarding the physical and chemical composition of engine lubricants, including "low ash content" (LOW SAPS) specifications.

[0014] Due to the ever stricter regulations regarding harmful emissions to the environment, the use of metallic detergents conventionally used in lubricants could be further restricted in the coming years.

[0015] Unfortunately, simply reducing the metallic detergent content is detrimental to the detergency properties of the lubricant and is thus detrimental to engine life.

[0016] Therefore, research has been directed towards the development of new low ash detergent compounds.

[0017] Applications WO2018 / 220007 and WO2018 / 220009 propose the use of compounds derived from salicylic acid, products of the reaction between salicylic acid, a boron compound and an amine compound, for example of the polyamine type, to formulate lubricating compositions, combining good anti-corrosion properties, wear resistance and good detergency performance.

[0018] Application WO2006 / 022934 describes a lubricating composition comprising a lubricating oil and a detergent / antioxidant additive produced from the reaction between an acidic organic compound and a boron compound. Statement of the invention

[0019] The present invention aims to provide a means for improving the detergency properties of lubricants, intended for mobile or stationary powertrain systems, in particular in light and heavy vehicles, while reducing the ash content.

[0020] More particularly, the invention relates, according to a first of its aspects, to the use, as a detergent additive in a lubricating composition intended for a motorization system, of at least one spiro compound of the following formula (I):

[0021] [Chem.l]

[0022] in which: M is an atom selected from boron (B) and aluminum (Al), in particular is a boron atom; ni and n2 are, independently of each other, 0, 1 or 2; and R represent, independently of one another, a hydrocarbon group comprising from 1 to 50 carbon atoms, in particular from 5 to 15 carbon atoms.

[0023] By "detergent additive" within the meaning of the present invention, is meant a compound which, introduced into a lubricant, makes it possible to provide and / or increase its detergent capacities and therefore to reduce, prevent or even eliminate deposits in the engine system.

[0024] In the remainder of the text, a spiro compound of formula (I) as defined above will be referred to more simply as "spiro compound" according to the invention. Examples of spiro compounds considered according to the invention are described more precisely in the rest of the text.

[0025] The invention also relates, according to another of its aspects, to a lubricating composition intended for the lubrication of a motorization system, in particular of a light or heavy motor vehicle, comprising at least: - one or more base oils; and - at least one spiro compound as defined previously and detailed in the rest of the text.

[0026] According to a particular embodiment, a lubricating composition according to the invention comprises, in addition to said spiro compound(s) according to the invention, one or more other detergent additives, in particular chosen from metallic detergent additives conventionally used in the field of lubricants, in particular based on calcium or magnesium.

[0027] As illustrated in the examples which follow, the inventors have discovered that it is possible, by supplementing a lubricant with a spiro compound as defined above, even in a low content, to significantly increase the detergency properties of the lubricant.

[0028] The detergency properties of the lubricant can be assessed by evaluating the performance of the lubricant in terms of thermal stability by an “MCT” test (for “Micro Coking Test” in English terminology) according to the GFC Lu-27-T-07 standard, as described in the examples. This test takes into account the tendency of the lubricant to form deposits / varnishes under high temperature conditions similar to those encountered in the hottest parts of the engine (from 230°C to 280°C).

[0029] Furthermore, as illustrated in example 2, the thermal stability of the detergent following the MCT test, enhanced by the addition of the spiro compound according to the invention, remains high even in the event of prolonged exposure of the lubricant to high temperatures.

[0030] Thus, advantageously, a lubricating composition according to the invention, supplemented by a spiro compound as defined above, retains good detergency capabilities, even after prolonged use, in other words even when it is worn.

[0031] For the purposes of the invention, the term "used" is understood to mean a lubricating composition used during at least one oil change interval, i.e. over a distance traveled by the vehicle of between 10,000 and 30,000 km, preferably between 15,000 and 30,000 km.

[0032] On the other hand, said spiro compound(s), used as detergent additives according to the invention, generate little ash compared to conventional metallic detergents.

[0033] Therefore, the use of one or more spiro compounds advantageously makes it possible to increase the detergency capacities of a lubricating composition, without negatively impacting the ash content generated by the lubricant.

[0034] Also, the addition of one or more spiro compounds according to the invention, capable of significantly increasing the detergency capacities of the lubricant, makes it possible to reduce the content of metallic detergents conventionally used in lubricants, for example based on calcium or magnesium, and undesirable given the ash that they generate, while maintaining, or even improving, the detergency capacity of the lubricant, compared to a lubricant free of spiro compound.

[0035] Advantageously, it is thus possible to reduce the harmful effects in terms of ash levels, in particular sulfated ash, linked to the use of conventional metallic detergents, without impacting the detergency properties of the lubricant, or even by improving the detergency.

[0036] A lubricating composition according to the invention thus makes it possible to combine excellent detergency properties and a low ash content, in particular sulfated ash.

[0037] Also, a lubricating composition according to the invention advantageously has good properties in terms of reducing the fuel consumption of motor vehicles, also known as “Fuel Eco” properties and, in fact, contributes to the reduction of CO2 emissions.

[0038] The invention also relates to a process or method for increasing the detergency capacity of a lubricating composition intended for a mobile or stationary motorization system, in particular of a lubricating composition using a reduced content of metallic detergents, comprising the addition to said lubricating composition of at least one spiro compound according to the invention.

[0039] The process or method according to the invention advantageously makes it possible to increase the detergency capacity of said composition, while maintaining a low ash content.

[0040] Finally, advantageously, by reducing the content of metallic detergents, in particular calcium-based detergents, the lubricant according to the invention makes it possible to reduce and / or prevent abnormal fuel combustion phenomena, in particular pre-ignition, in particular low-speed pre-ignition (known as "Low Speed Pre-Ignition" in English or "LSPI") and / or knocking in an engine lubricated by a lubricant according to the invention (Kocsis et al., "The Impact of Lubricant Volatility, Viscosity and Detergent Chemistry on Low Speed Pre-Ignition Behavior", SAE Int. J. Engines, 10(3):1019-1035, 2017; Ritchie et al., "Controlling Low-Speed Pre-Ignition in Modern Automotive Equipment, Part 3: Identification of Key Additive Comportent Types and Other Lubricant Composition Effects on Low-Speed Pre-Ignition”, SAE Int. J. Engines, 9(2): 832-840, 2016).

[0041] Thus, the spiro compound is advantageously used according to the invention as a detergent additive in a lubricating composition, to prevent and / or reduce abnormal combustion of the fuel, in particular pre-ignition, in particular LSPI, and / or knocking, in an engine lubricated by means of said lubricating composition.

[0042] By "abnormal combustion" is meant any phenomenon during which all or part of the fuel mixture is ignited in an uncontrolled manner within the combustion chamber of an engine, in particular a vehicle engine, in particular a motor vehicle engine. By abnormal combustion according to the invention, is meant more particularly the phenomena of pre-ignition, including low-speed pre-ignition (LSPI); and knocking, including super-knock or mega-knock which can follow a pre-ignition event.

[0043] By "pre-ignition" according to the invention, it is meant to include the phenomenon of low frequency vibration producing a humming sound effect (or "Rumble" in English). More particularly, "pre-ignition" is low speed pre-ignition (LSPI).

[0044] The lubricants considered according to the invention, advantageously having excellent detergency properties, a reduced ash content, good “Fuel Eco” properties and reduction / prevention of abnormal combustion phenomena of the fuel, in particular of LSPI, can be implemented for various motorization systems, mobile or stationary, in particular for motorization systems comprising a Diesel, gasoline, gas or dual-fuel engine, in particular Diesel or gasoline.

[0045] For the purposes of the present invention, the term "motorization system" is intended to denote a system comprising all the mechanical parts necessary for the intended mobile or stationary application and including at least one engine, in particular an internal combustion engine. It may be a combustion, gas, in particular hydrogen, ammonia, electric or hybrid motorization system, depending on the nature of the engine(s) included in the motorization system: combustion, gas, in particular hydrogen, ammonia and / or electric engine.

[0046] A “mobile” motorization system is more particularly a motorization system implemented in vehicles, including light vehicles, heavy goods vehicles, so-called “off-road” mobile machines, or even marine vehicles.

[0047] A mobile motorization system thus corresponds more particularly to the propulsion system of a vehicle.

[0048] For the purposes of the present invention, the term “propulsion system” is understood to mean a system comprising the mechanical parts necessary for propelling a vehicle. The propulsion system more particularly includes an engine, a transmission and possibly a battery. The battery itself is generally made up of a set of electrical accumulators, called cells.

[0049] A “stationary” motorization system within the meaning of the invention is a motorization system including a stationary engine. It may, for example, find applications in devices for producing electrical energy. It may in particular be a gas-powered motorization system, in particular a stationary gas-powered engine.

[0050] A “Diesel engine” within the meaning of the invention is a combustion engine whose fuel is diesel.

[0051] According to a particular embodiment, a lubricating composition according to the invention is implemented in a propulsion system of a light motor vehicle or a heavy goods vehicle, preferably for a gasoline or diesel engine.

[0052] The lubricating compositions according to the invention are particularly suitable for gasoline and diesel engine systems, equipped with exhaust gas post-treatment systems, such as particulate filters (DPF).

[0053] The invention also relates, according to another of its aspects, to a process or method for lubricating a mobile or stationary motorization system, in particular a Diesel, gasoline, gas or dual-fuel engine, in particular in a light or heavy motor vehicle, comprising a step of bringing at least one mechanical part of said system into contact with a lubricating composition as defined above.

[0054] Other characteristics, variants and advantages of the implementation of a spiro compound according to the invention will emerge more clearly on reading the description and examples which follow, given by way of illustration and not limitation of the invention.

[0055] In the remainder of the text, the expressions “between ... and ...”, “ranging from ... to ...” and “varying from ... to ...” are equivalent and are intended to mean that the limits are included, unless otherwise stated. Brief description of the drawings

[0056] [Fig-1] presents a histogram of the rating results according to the MCT test for the reference lubricants 1 and 2 and for the lubricating compositions according to the invention II and 12 supplemented with a spiro compound according to the invention, as described in examples 1 and 2. Detailed description SPIRO compound

[0057] As indicated previously, the invention is based on the implementation, in a lubricant for a motorization system, of one or more specific spiro compounds, as an additive to improve the detergency of the lubricant.

[0058] It is understood that the invention can implement a single spiro compound or a mixture of at least two distinct spiro compounds, in particular three or four distinct spiro compounds, in particular as defined below.

[0059] As mentioned previously, the spiro compound considered according to the invention is of the following formula (I):

[0060] [Chem.2]

[0061] in which: M is an atom selected from boron and aluminum, in particular is a boron atom; ni and n2 are, independently of each other, 0, 1 or 2; and R represent, independently of one another, a hydrocarbon group comprising from 1 to 50 carbon atoms, in particular from 5 to 15 carbon atoms.

[0062] The hydrocarbon groups considered according to the invention may optionally be interrupted by one or more heteroatoms, for example -O-, -NH-, -N= or -S-, in particular -O- or -NH-; and / or optionally substituted by one or more -OH, -NH2 and -SH groups, in particular -OH or -NH2.

[0063] According to a particular embodiment, the R groups are composed solely of carbon and hydrogen atoms.

[0064] The hydrocarbon groups may in particular be alkyl, alkenyl, aryl or aralkyl groups.

[0065] According to a particular embodiment, the substituents R represent, independently of one another, a hydrocarbon group, preferably an aliphatic chain, linear or branched, comprising from 3 to 50 carbon atoms, in particular from 3 to 30 carbon atoms, in particular from 5 to 25 carbon atoms and more particularly from 8 to 15 carbon atoms.

[0066] In particular, the substituents R may represent, independently of one another, a linear or branched aliphatic chain, in particular an alkyl chain, preferably linear, from C1 to C50; in particular from C3 to C30, in particular from C5 to C25 and more particularly from C8 to C15, for example from C10.

[0067] According to a particular embodiment, n1 and n2 are equal to 0.

[0068] According to another particular embodiment, n1 and n2 are equal to 1 or 2.

[0069] When ni is 2 or n2 is 2, the R groups, carried by the same cycle, can be identical or different.

[0070] According to a particular embodiment, the spiro compound may be of formula (I) above, in which n1 and n2 are 1; the substituents R may be identical or different, preferably identical.

[0071] According to a particular embodiment, the spiro compound is of formula (I) above, in which: ni and n2 are 1; and the R groups, which are identical, represent alkyl groups, preferably linear, from C1 to C50, in particular from C3 to C30, in particular from C5 to C23 and more particularly from C8 to C15, even more preferably from C10.

[0072] According to a particular embodiment, the spiro compound is of formula (I) in which M is a boron atom.

[0073] In other words, according to this particular embodiment, the spiro compound can be a so-called spiroboronate compound, of the following formula (!):

[0074] [Chem.3]

[0075] in which n1 and n2 and R are as defined above.

[0076] According to another particular embodiment, the spiro compound is of formula (I) in which M is an aluminum atom.

[0077] In other words, according to this particular embodiment, the spiro compound can be a so-called spiroaluminate compound, of the following formula (I”):

[0078] [Chem.4]

[0079] in which n1, n2 and R are as defined above.

[0080] The invention thus relates, according to another of its aspects, to a spiro compound of formula (I) above, in which:

[0081] - M is an aluminum atom; - ni and n2 are, independently of each other, 0, 1 or 2, at least one of ni and n2 being 1 or 2; preferably ni and n2 are 1; and - the R groups represent, independently of one another, an aliphatic chain, linear or branched, in particular an alkyl chain, preferably linear, comprising from 5 to 50 carbon atoms, in particular from 6 to 30 carbon atoms, in particular from 8 to 25 carbon atoms and more particularly from 10 to 15 carbon atoms.

[0082] In other words, the invention relates to a spiroaluminate type compound of formula (I”) above, in which: - ni and n2 are, independently of each other, 0, 1 or 2, at least one of ni and n2 being 1 or 2; preferably ni and n2 are 1; and - the R groups represent, independently of one another, an aliphatic chain, linear or branched, in particular an alkyl chain, preferably linear, comprising from 5 to 50 carbon atoms, in particular from 6 to 30 carbon atoms, in particular from 8 to 25 carbon atoms and more particularly from 10 to 15 carbon atoms.

[0083] According to a particular embodiment, the spiroaluminate type compound according to the invention is of formula (I”) in which: - ni and n2 are equal to 1; and - the R groups, identical or different, preferably identical, represent alkyl chains, preferably linear, comprising from 5 to 50 carbon atoms, in particular from 6 to 30 carbon atoms, in particular from 8 to 25 carbon atoms and more particularly from 10 to 15 carbon atoms.

[0084] The spiro compound used according to the invention can be prepared from at least salicylic acid or a salicylic acid derivative and a boron compound or an aluminum compound.

[0085] More particularly, it can be obtained by reaction: - at least one compound chosen from salicylic acid and its derivatives, of the following formula (Ia):

[0086] [Chem.5]

[0087] in which R is as defined previously and n is as defined previously for n1 and n2; and - at least one boron or aluminum compound, in particular boric acid or aluminum hydroxide.

[0088] The preparation of the spiro compound used in the lubricating composition according to the invention does not involve any step, subsequent to the reaction of salicylic acid or one of its derivatives with said boron or aluminum compound, of reaction with an amine compound, as is the case for example in the context of the preparation of the compounds proposed in applications WO2018 / 220007 and WO2018 / 220009.

[0089] Salicylic acid and its derivatives of formula (Ia) above can be synthesized according to synthesis methods known to those skilled in the art or be commercially available.

[0090] The boron compound (in other words, based on boron) can be chosen in particular from boric acid (B(OH)3), boronic acids, boric and boronic esters, boron oxide and boric acid complexes.

[0091] In particular, the boron compound may be chosen from boric acid; boron oxide; boric acid complexes; trialkyl borates, in particular in which the alkyl groups comprise, independently of one another, from 1 to 4 carbon atoms; boronic acids having a C1-C12 alkyl group; boric acids substituted by two alkyl groups, in particular C1 to C12; boric acids substituted by two aryl groups, in particular C6 to C12; boric acids substituted by one or two aralkyl groups, in particular C7 to C12, and derivatives of these compounds obtained by substitution of at least one alkyl group by one or more alkoxy groups.

[0092] Boric acid complexes are in particular complexes of boron with one or more molecules comprising one or more alcohol functions.

[0093] According to a particular embodiment, the boron compound is boric acid.

[0094] The aluminum compound (in other words, aluminum-based) may be, for example, chosen from aluminum hydroxide (A1(OH)3), aluminum oxide, aluminum sulfate (A12SO4)3.

[0095] It is up to the person skilled in the art to adjust the reaction conditions between said compound(s) (Ia) and the boron or aluminum compound to obtain the desired spiro compound.

[0096] In particular, the reaction can be carried out in a solvent medium consisting of one or more apolar solvents and / or protic polar solvents.

[0097] The solvent medium may consist of one or more solvents chosen from naphtha, protic polar solvents, such as water and alcohols, for example methanol, ethanol, propanol, butanol; and mixtures thereof.

[0098] In the context of the invention, the following terms are understood to mean: - “hydrocarbon group”, a saturated or unsaturated, linear, branched or cyclic, aromatic or not, radical comprising carbon and hydrogen; - “aliphatic chain” means a hydrocarbon group consisting exclusively of carbon and hydrogen atoms, linear or branched, saturated or unsaturated, non-aromatic. Preferably, an aliphatic chain is an alkyl chain; - “alkyl” means a saturated, linear or branched aliphatic group; for example, a Cx to Cz alkyl represents a saturated carbon chain of x to z carbon atoms, linear or branched; - “alkenyl” means a mono- or polyunsaturated, linear or branched aliphatic group; - “cycloalkyl”, a cyclic alkyl group, for example a Cx to Cz cycloalkyl represents a cyclic carbon group of x to z carbon atoms, for example a cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl; - “aryl”, a mono- or polycyclic aromatic group, in particular comprising between 6 and 10 carbon atoms. Examples of aryl groups include phenyl or naphthyl groups; - “aralkyl”, an aryl group as defined above, substituted by at least one alkyl group as defined above.

[0099] Said spiro compound(s) are advantageously used in a content sufficient to achieve the required level of detergency capacity of the lubricant. Advantageously, even a small amount of spiro compound(s), in particular less than 2% by mass, in particular less than or equal to 1% by mass, relative to the total mass of said lubricating composition, makes it possible to significantly increase the detergency capacity of the lubricant.

[0100] Of course, the quantity used in spiro compound(s) can be adjusted according to the nature of the lubricant, and more particularly taking into account the presence or absence and the quantity used in other detergent additive(s), in particular metallic additive(s), for example calcium-based, present in the lubricant.

[0101] Generally speaking, said spiro compound(s) considered according to the invention, in particular as defined above, may be used in an amount of 0.1 to 20% by mass, in particular 0.2 to 15% by mass, in particular 0.5 to 10%, and more particularly 0.5 to 5.0% by mass, relative to the total mass of said lubricating composition. LUBRICATING COMPOSITION

[0102] A lubricating composition as considered according to the invention more particularly comprises one or more base oils and, optionally, other additives conventionally considered in lubricating compositions.

[0103] It is understood that the nature and quantity of the other additives are adapted with regard to the intended purpose of the lubricant, and more particularly with regard to the type of engine system for which it is intended, for example depending on whether it is intended for use in a light vehicle engine, a heavy goods vehicle engine, a diesel or petrol engine, etc. Base oil

[0104] Conventionally, a lubricating composition comprises one or more base oils.

[0105] These base oils can be chosen from base oils conventionally used in the field of lubricating oils, such as mineral, synthetic or natural, animal or vegetable oils or their mixtures.

[0106] It may be a mixture of several base oils, for example a mixture of two, three or four base oils.

[0107] The base oils of the lubricating compositions considered according to the invention may in particular be oils of mineral or synthetic origin belonging to groups I to V according to the classes defined in the API classification (or their equivalents according to the ATIEL classification) and presented in table A below or their mixtures.

[0108] [Tables] Saturates content Sulphur content Viscosity index (VI) Group I Mineral oils < 90% > 0.03% 80 <VI< 120 Groupement II Huiles hydrocraquées > 90% <0.03% 80 <VI < 120 Groupement III Huiles hydrocraquées ou hydro-isomérisées >90% <0.03% >120 Group IV Polyalphaolefins (PAO) Group V Esters and other bases not included in groups I to IV Table A

[0109] Mineral base oils include all types of base oils obtained by atmospheric and vacuum distillation of crude oil, followed by refining operations such as solvent extraction, de-alphatting, solvent dewaxing, hydrotreating, hydrocracking, hydroisomerization and hydrofinishing.

[0110] Synthetic base oils may be esters of carboxylic acids and alcohols, polyalphaolefins or polyalkylene glycols (PAG) obtained by polymerization or copolymerization of alkylene oxides comprising from 2 to 8 carbon atoms, in particular from 2 to 4 carbon atoms. The polyalphaolefins used as base oils are for example obtained from monomers comprising 4 to 32 carbon atoms, for example from decene, octene or dodecene, and whose viscosity at 100°C is between 1.5 and 15 mm2.s 1 according to the ASTM D445 standard. Their average molecular mass is generally between 250 and 3000 according to the ASTM D5296 standard.

[0111] Mixtures of synthetic and mineral oils, which can be biosourced, can also be employed.

[0112] There is generally no limitation on the use of different base oils in the lubricating composition, except that they must have properties, in particular viscosity, viscosity index, sulfur content or oxidation resistance, suitable for use in powertrain systems, in particular vehicle engines.

[0113] Preferably, a lubricating composition considered according to the invention comprises at least one base oil chosen from oils of group II, III and IV of the API classification, and their mixtures.

[0114] In particular, such a lubricating composition may comprise at least one group III base oil, in particular a mixture of at least two group III base oils.

[0115] The base oils suitable for the invention may have a kinematic viscosity measured at 40°C according to the ASTM D445 (KV40) standard ranging from 10 to 100 mm2 / s, in particular from 12 to 50 mm2 / s, more particularly from 15 to 40 mm2 / s.

[0116] The base oils suitable for the invention may have a kinematic viscosity measured at 100°C according to the ASTM D445 (KV100) standard ranging from 1 to 15 mm2 / s, in particular from 2 to 10 mm2 / s, more particularly from 4 to 8 mm2 / s.

[0117] The base oil(s) may be present in a lubricating composition according to the invention in a content of at least 50% by mass, relative to its total mass, in particular at least 60% by mass, more particularly ranging from 60 to 99% by mass and preferably from 70 to 90% by mass.

[0118] Preferably, the group III oil or oils represent(s) at least 50% by mass, in particular at least 60% by mass, more particularly between 70 and 100% by mass, for example between 80 and 100% by mass, of the total mass of the base oils of the composition. ADDITIVES

[0119] A lubricating composition according to the invention may comprise all types of additives suitable for the intended use of the lubricant, as detailed in the remainder of the text, for example for use in engine systems of light or heavy vehicles, in particular Diesel engines.

[0120] In particular, in the case where it is sought to formulate a lubricant having a low ash content, it is understood that the additives are chosen so as not to significantly impact the ash content of the lubricating composition.

[0121] These additives can be introduced in isolation and / or in the form of a mixture, or "additive package", like those already available for sale for formulations of commercial lubricants for vehicle engines, of performance level as defined by the ACEA (Association of European Automobile Manufacturers) and / or the API (American Petroleum Institute), well known to those skilled in the art.

[0122] These additives, distinct from said spiro compound(s), may in particular be chosen from other detergent additives, distinct from said spiro compound(s), in particular metallic detergent additives, friction modifiers, anti-wear additives, extreme pressure additives, antioxidants, wear improvers, etc. viscosity index (VI), pour point depressants (PPD), dispersants, antifoaming agents, thickeners, corrosion inhibitors, and mixtures thereof.

[0123] Advantageously, a lubricating composition according to the invention comprises one or more additives chosen from other detergent additives, distinct from said spiro compound(s), in particular chosen from metallic detergent additives, viscosity index improvers, pour point lowering additives, anti-wear additives, antioxidants and mixtures thereof. Other detergents

[0124] The lubricating composition considered according to the invention, supplemented by one or more spiro compounds according to the invention, in particular as defined previously, may comprise one or more other detergent additives, in particular one or more metallic detergent additives.

[0125] As mentioned above, metallic detergents are known to those skilled in the art to provide high levels of detergency. However, these metallic compounds have the disadvantage of generating sulfated ash.

[0126] These are generally anionic compounds comprising a long lipophilic hydrocarbon chain and a hydrophilic head, the associated cation possibly being a metal cation of an alkali or alkaline earth metal.

[0127] They are generally chosen from alkali metal or alkaline earth metal salts of carboxylic acids, in particular sulfonates, salicylates, naphthenates, phenates, carboxylates and mixtures thereof. The alkali and alkaline earth metals are preferably calcium, magnesium, sodium or barium.

[0128] These metal salts generally comprise the metal in a stoichiometric quantity or in excess, therefore in a quantity greater than the stoichiometric quantity. These are then overbased detergent additives; the excess metal providing the overbased character to the detergent additive is then generally in the form of a metal salt insoluble in the base oil, for example a carbonate, a hydroxide, an oxalate, an acetate, a glutamate, preferably a carbonate.

[0129] According to a particular embodiment, a lubricating composition according to the invention comprises at least one metallic detergent additive, distinct from the spiro compounds according to the invention, in particular chosen from salts of alkali metals or alkaline-earth metals, overbased or not, in particular from calcium salts, magnesium salts and their mixtures.

[0130] Thus, according to a particular embodiment, a lubricating composition according to the invention, intended for a motorization system, in particular for a light or heavy motor vehicle, comprises at least: - one or more base oils; - at least one spiro compound according to the invention; and - at least one metallic detergent additive distinct from said spiro compound, in particular as defined above, notably chosen from calcium and magnesium salts and their mixtures.

[0131] In particular, a lubricating composition according to the invention may comprise at least one calcium-based detergent additive, such as a calcium sulfonate, salicylate, naphthenate, phenate, carboxylate or a mixture thereof, in particular a calcium-based detergent additive overbased, for example by calcium carbonate.

[0132] Advantageously, as indicated above, by the addition of one or more spiro compounds according to the invention, making it possible to significantly increase the detergency capacity of the lubricant, the content of metallic detergent additives as defined above, undesirable with regard to the ash that they generate, can be reduced, while retaining good detergency properties.

[0133] According to a particular embodiment, the lubricating composition according to the invention may comprise less than 15% by mass, in particular less than 10% by mass and more particularly from 0.1 to 10% by mass, in particular from 0.5% to 5.0% by mass, of metallic detergent additive(s) distinct from the spiro compounds according to the invention, relative to the total mass of said composition.

[0134] In particular, said metallic detergent additive(s) may be present in the lubricating composition so as to provide a content of metallic element(s), in particular calcium, of less than or equal to 6000 ppm, in particular ranging from 100 ppm to 4000 ppm, preferably from 250 ppm to 3000 ppm.

[0135] Lowering the content of metallic detergents, such as calcium and magnesium salts, advantageously makes it possible to meet the specifications of “LOW SAPS” lubricating compositions.

[0136] Advantageously, a lubricating composition according to the invention thus has a sulfated ash content, determined according to the ASTM D-874 standard, less than or equal to 2% by mass, in particular less than or equal to 1.5% by mass, and more particularly less than or equal to 1% by mass, relative to the total mass of said lubricating composition.

[0137] According to a particular embodiment, a lubricating composition according to the invention may comprise: - from 60 to 99.8% by mass, preferably from 70 to 90% by mass, of one or more base oils; - from 0.1 to 20% by mass, in particular from 0.2 to 15% by mass and more particularly from 0.5 to 10% by mass of at least one spiro compound according to the invention, such as as previously defined; and - from 0.1 to 10% by mass, in particular from 0.5 to 5% by mass, of one or more metallic detergent additives, distinct from said spiro compound according to the invention, in particular as defined above, notably chosen from calcium and magnesium salts and their mixtures; the contents being expressed relative to the total mass of said lubricating composition. Other additives

[0138] A lubricating composition considered according to the invention may also comprise one or more other additives, distinct from said spiro compound(s), chosen from friction modifying additives, anti-wear additives, extreme pressure additives, antioxidants, viscosity index improvers, pour point lowering additives, dispersants, anti-foaming agents, thickeners, corrosion inhibitors, and mixtures thereof.

[0139] Thus, a lubricating composition considered according to the invention may also comprise at least one viscosity index (VI) improver. Viscosity index (VI) improvers, in particular viscosity index improving polymers, make it possible to guarantee good cold resistance and minimal viscosity at high temperature. Examples of viscosity index improving polymers include polymer esters, homopolymers or copolymers, hydrogenated or non-hydrogenated, of styrene, butadiene and isoprene, homopolymers or copolymers of olefin, such as ethylene or propylene, polyacrylates and polymethacrylates (PMA).

[0140] Advantageously, a lubricating composition according to the invention comprises at least one viscosity index improver chosen from polymethacrylates (PMA) and hydrogenated polyisoprene-styrenes (PISH), linear, grafted, comb or star, preferably star.

[0141] In particular, the viscosity index improving additive(s) may be present in a lubricating composition according to the invention in a content ranging from 1 to 15% by mass, in particular from 2 to 10% by mass, relative to the total mass of the lubricating composition.

[0142] According to one embodiment, a lubricating composition according to the invention is free of additive improving the viscosity index.

[0143] A lubricating composition considered according to the invention may comprise at least one friction modifying additive.

[0144] The friction modifying additives may be chosen from compounds providing metallic elements and ash-free compounds, preferably from ash-free compounds.

[0145] Among the compounds providing metallic elements, mention may be made of transition metal complexes such as Mo, Sb, Sn, Fe, Cu, Zn, the ligands of which may be hydrocarbon compounds comprising oxygen, nitrogen, sulfur or phosphorus atoms.

[0146] Advantageously, the friction modifying additives are chosen from ash-free compounds, generally of organic origin and which may be more particularly chosen from monoesters of fatty acids and polyols, alkoxylated amines, alkoxylated fatty amines, fatty epoxides, borate fatty epoxides, fatty amines or fatty acid glycerol esters. According to the invention, the fatty compounds comprise at least one hydrocarbon group comprising from 10 to 24 carbon atoms.

[0147] According to an advantageous variant, a lubricating composition comprises at least one friction modifying additive, in particular based on molybdenum.

[0148] In particular, the molybdenum-based compounds may be chosen from molybdenum dithiocarbamates (Mo-DTC), molybdenum dithiophosphates (Mo-DTP), and mixtures thereof.

[0149] Advantageously, a lubricating composition considered according to the invention may comprise from 0.01 to 5% by mass, preferably from 0.01 to 5% by mass, more particularly from 0.1 to 2% by mass or even more particularly from 0.1 to 1.5% by mass, relative to the total mass of the lubricating composition, of friction modifying additives.

[0150] A lubricating composition according to the invention may comprise at least one anti-wear and / or extreme pressure additive.

[0151] Anti-wear additives and extreme pressure additives protect friction surfaces by forming a protective film adsorbed on these surfaces.

[0152] There is a wide variety of anti-wear additives. Preferably for the lubricating composition according to the invention, the anti-wear additives are chosen from phospho-sulfur additives such as metal alkylthiophosphates, in particular zinc alkylthiophosphates, and more specifically zinc dialkyldithiophosphates or ZnDTP. The preferred compounds are of formula Zn((SP(S)(OR3)(OR4))2, in which R3 and R4, identical or different, independently represent an alkyl group, preferably an alkyl group comprising from 1 to 18 carbon atoms.

[0153] Amine phosphates are also anti-wear additives that can be used in the lubricating composition according to the invention. However, the phosphorus provided by these additives can act as a poison for automobile catalytic systems because these additives generate ash. These effects can be minimized by partially substituting the amine phosphates with additives that do not provide phosphorus, such as, for example, polysulfides, in particular sulfur-containing olefins. Advantageously, the extreme pressure and / or anti-wear additive(s) may be present in a lubricating composition according to the invention in a content ranging from 0.01 to 6% by mass, preferably from 0.05 to 4% by mass, more preferably from 0.1 to 2% by mass relative to the total mass of lubricating composition.

[0154] A lubricating composition considered according to the invention may comprise at least one antioxidant additive. The antioxidant additives are essentially dedicated to delaying the degradation of the lubricating composition in service. This degradation may in particular result in the formation of deposits, the presence of sludge or an increase in the viscosity of the lubricating composition. They act in particular as radical inhibitors or hydroperoxide destroyers.

[0155] Among the commonly used antioxidant additives, mention may be made of phenolic type antioxidant additives, amine type antioxidant additives, phosphosulfur antioxidant additives. Some of these antioxidant additives, for example phosphosulfur antioxidant additives, may be ash-generating. The phenolic antioxidant additives may be ash-free or in the form of neutral or basic metal salts. The antioxidant additives may in particular be chosen from sterically hindered phenols, sterically hindered phenol esters and sterically hindered phenols comprising a thioether bridge, diphenylamines, diphenylamines substituted by at least one C1-C12 alkyl group, N,N'-dialkyl-aryl-diamines and mixtures thereof.

[0156] Preferably, the sterically hindered phenols are chosen from compounds comprising a phenol group of which at least one vicinal carbon of the carbon carrying the alcohol function is substituted by at least one C1-C10 alkyl group, preferably a C1-C6 alkyl group, preferably a C4 alkyl group, preferably by the tert-butyl group.

[0157] Amino compounds are another class of antioxidant additives that can be used, optionally in combination with phenolic antioxidant additives. Examples of amine compounds are aromatic amines, for example aromatic amines of formula NR5R6R7 in which R5 represents an aliphatic group or an aromatic group, optionally substituted, R6 represents an aromatic group, optionally substituted, R7 represents a hydrogen atom, an alkyl group, an aryl group or a group of formula R8S(O)ZR9 in which R8 represents an alkylene group or an alkenylene group, R9 represents an alkyl group, an alkenyl group or an aryl group and z represents 0, 1 or 2.

[0158] Sulfurized alkyl phenols or their alkali and alkaline earth metal salts can also be used as antioxidant additives.

[0159] A lubricating composition considered according to the invention may contain all types of antioxidant additives known to those skilled in the art. Advantageously, the lubricating composition comprises at least one ash-free antioxidant additive.

[0160] Also advantageously, a lubricating composition considered according to the invention may comprise from 0.1 to 2% by mass, relative to the total mass of the composition, of at least one antioxidant additive.

[0161] A lubricating composition considered according to the invention may comprise at least one pour point depressant additive (also called “PPD” agents for “Pour Point Depressant” in English). By slowing down the formation of paraffin crystals, the pour point depressant additives generally improve the cold behavior of the lubricating composition.

[0162] Examples of pour point reducing agents include polyalkyl methacrylates, polyacrylates, polyarylamides, polyalkylphenols, polyalkylnaphthalenes, and alkylated polystyrenes.

[0163] A lubricating composition considered according to the invention may also comprise at least one dispersing agent. The dispersing agents ensure the maintenance in suspension and the evacuation of insoluble solid contaminants constituted by the secondary oxidation products which form when the lubricating composition is in service. They may be chosen from Mannich bases, succinimides and their derivatives.

[0164] In particular, a lubricating composition considered according to the invention may comprise from 0.2 to 10% by mass of dispersing agent(s), relative to the total mass of the composition.

[0165] A lubricating composition considered according to the invention may also comprise at least one anti-foam additive. The anti-foam additives may be chosen from polar polymers such as polymethylsiloxanes or polyacrylates.

[0166] In particular, a lubricating composition considered according to the invention may comprise from 0.01 to 3% by mass of anti-foam additive(s), relative to the total mass of the lubricating composition.

[0167] As mentioned above, all of the additives detailed above may be introduced in the form of a mixture or "package" of additives.

[0168] According to this embodiment, the package of additives can represent from 1% to 30% by mass relative to the total mass of the composition, in particular from 1 to 20% by mass, in particular from 3% to 15% by mass and more particularly from 5 to 15% by mass.

[0169] According to a particular embodiment, a lubricating composition according to the invention may comprise, or even consist of: - a base oil or a mixture of base oils; - one or more spiro compounds according to the invention, in particular as defined above; and - optionally one or more additives, distinct from said spiro compound(s), chosen from other detergent additives, in particular metallic detergent additives, friction modifiers, anti-wear additives, extreme pressure additives, antioxidants, viscosity index (VI) improvers, pour point depressant (PPD) additives, dispersants, anti-foaming agents, thickeners, corrosion inhibitors, and mixtures thereof.

[0170] Preferably, a lubricating composition formulated according to the invention comprises, or even consists of: - from 60 to 98.9% by mass, in particular from 70 to 90% by mass, of one or more base oils; - from 0.1 to 20% by mass, preferably from 0.5 to 10% by mass, of one or more spiro compounds according to the invention as defined above; and - from 1% to 30% by mass, preferably from 3% to 20% by mass, of one or more additive(s) chosen from other detergent additives, distinct from said spiro compound(s), in particular chosen from metallic detergent additives; anti-wear agents; antioxidants; dispersants; viscosity index improvers and mixtures thereof; the contents being expressed relative to the total mass of said lubricating composition.

[0171] In particular, a lubricating composition formulated according to the invention may comprise, or even consist of: - from 60 to 99.8% by mass, in particular from 70 to 90% by mass, of one or more base oils; - from 0.1 to 20% by mass, preferably from 0.5 to 10% by mass, of one or more spiro compounds according to the invention as defined above; - from 0.1 to 10% by mass, in particular from 0.5 to 5% by mass, of one or more metallic detergent additives distinct from said spiro compound(s), in particular as defined above, notably chosen from calcium and magnesium salts and their mixtures; and - optionally from 1% to 30% by mass, preferably from 3% to 20% by mass, of one or more other additives chosen from anti-wear agents, antioxidants, viscosity index improvers and mixtures thereof, the contents being expressed relative to the total mass of said lubricating composition.

[0172] According to a particular embodiment, a lubricating composition according to the invention may have a kinematic viscosity, measured at 40°C according to the standard ASTM D445, between 20 mm2 / s and 50 mm2 / s, preferably between 25 mm2 / s and 40 mm2 / s.

[0173] Advantageously, a lubricating composition according to the invention has a kinematic viscosity, measured at 100°C according to the ASTM D445 standard, of between 2 mm2 / s and 20 mm2 / s, preferably between 4 mm2 / s and 15 mm2 / s. APPLICATION

[0174] As indicated previously, the lubricating compositions considered according to the invention may be intended for mobile or stationary motorization systems, in particular for gasoline, diesel, gas or dual-fuel engines.

[0175] The invention thus relates, according to another of its aspects, to the use of a composition as defined previously, incorporating one or more spiro compounds as detergent additive, for lubricating a mobile or stationary motorization system.

[0176] The lubricating compositions according to the invention may in particular be intended for engine systems including an internal combustion engine, and more particularly a diesel or gasoline engine, preferably a Diesel engine.

[0177] According to a particular embodiment, they are implemented for the lubrication of a motorization system of a vehicle, more particularly of a light or heavy vehicle, for example trucks.

[0178] In particular, they can be adapted for the lubrication of gasoline or diesel engine systems, equipped with exhaust gas post-treatment systems, in particular diesel particulate filters (DPF).

[0179] All of the characteristics and particular modes relating to the spiro compound of formula (I) and to the lubricating composition comprising it also apply to the uses, processes and methods targeted according to the invention.

[0180] The invention will now be described by means of the following examples, given as an illustration and not as a limitation of the invention. Measurement of thermal stability

[0181] The performance of the compositions in terms of thermal stability is evaluated by MCT (for “Micro Coking Test” in English), according to the GFC Lu-27-T-07 standard.

[0182] The MCT test evaluates the tendency of a composition to form deposits (or varnishes) on a hot surface (coking). It reports on the thermal stability of a thin-layer composition, subjected to temperature conditions similar to those encountered in the hottest parts of the engine (230 to 280°C). The deposits and varnishes are measured by a video rater. The result is expressed as a score out of 10, called merit, according to the CEC M-02-A-78 method. The higher the value of The higher the MCT, the better the thermal stability of the lubricating composition.

[0183] The test conditions are as follows: - 600 pl of oil; - duration: 90 minutes; - 1.5% inclined plate; - temperature gradient from 230 to 280°C; - video rating of the plate varnishes: score from 0 to 10, best result 10.

[0184] Furthermore, the temperature from which the varnish deposition occurs is also determined. The higher this temperature, the better the thermal stability of the lubricating composition. Example 1

[0185] Evaluation of the detergency properties linked to the addition of spiroboronate

[0186] The effect of adding a spiroboronate compound was evaluated on two lubricants, noted reference 1 and reference 2, intended for heavy goods vehicles, the composition of which is detailed in the following table. The lubricants are formulated by simple mixing at 60°C of the different components.

[0187] [Tables2] Reference 1 Reference 2 Base oil 1(1* [%] 65.2 62.7 Base oil 2*2) [%] 20 20 Additive package 1(3) [%] 8 - Additive package 2!41 [%] - 12.5 PISH polymer [%] 6.8 4.8 tn Group III base oil (KV100 = 6.3-6.7 mm%, K.V40 = 37 mm%, VI above 125) commercially available for example from SK Lubricantes under the trade name “Yubase® 6”. w Group III base oil (KV100 = 4.2 mm2 / s, KV40 = 19.1 mm2 / s, VI of 126) commercially available, for example, from SK Lubricantes under the trade name “Yubase® 4”. l3) Package of additives commonly used in the lubricant sector and commercially available. It includes anti-wear agents of the zinc dithiopliosphate type, calcium-based detergents and PIBSI-type dispersants. A package of additives commonly used in the lubricant sector and commercially available. It includes zinc dithiophosphate anti-wear agents, calcium-based detergents and PIBSI-type dispersants.

[0188] Two lubricating compositions in accordance with the invention, denoted II and 12, are prepared by supplementing reference lubricants 1 and 2 respectively with a spiroboronate compound in accordance with the invention (spiro compound of formula (I) in which M is a boron atom, R each represent a decyl group and ni and n2 are 1), at a rate of 1% by mass relative to the reference lubricant.

[0189] The properties in terms of thermal stability of the reference lubricants 1 and 2 and of the lubricating compositions II and 12 according to the invention, incorporating a spiroboronate compound according to the invention, are evaluated according to the MCT protocol described above.

[0190] The rating results (MCT at 90 min) are gathered in the following table and are presented on the histogram in [Fig.l]. The temperature values from which the formation of deposits occurs (TDépôt) are also gathered in the following table.

[0191] [Tables3] Reference 1 Reference 2 II (ref 1 + 1% spiroboronate) 12 (ref2 + 1% spiroboronate) MCT at 90 min(D) 4.4 8 8.8 9.4 Toépôt (°C) 235 249 264 272 Values are expressed with a standard deviation of ± 1%

[0192] The compositions according to the invention, supplemented with a spiroboronate compound according to the invention, exhibit an excellent rating, superior to those obtained with the reference lubricants, which demonstrates significantly increased thermal stability under high temperature conditions (from 230°C to 280°C).

[0193] These results are confirmed by deposit formation temperatures for the compositions according to the invention which are much higher than those obtained with the reference lubricants.

[0194] Thus, the addition of a spiroboronate compound according to the invention makes it possible to significantly increase the thermal stability of the lubricant. The lubricants will thus form less deposit / varnish under the conditions of implementation at the level of the vehicle engine system, and thus have improved detergency properties. Example 2

[0195] Maintenance of detergency properties during lubricant aging

[0196] The reference lubricants and the lubricating compositions according to the invention, as prepared in Example 1, are evaluated according to the modified MCT test to subject the lubricant layers to high temperature (from 230 to 280 °C) for a duration three times longer (3 times 90 minutes). Such conditions make it possible to simulate aging of the lubricant.

[0197] The rating results, under the different conditions of the MCT test, are collected in the following table, and are presented on the histogram of [Fig. 1]. The temperature values from which the formation of deposits occurs (TDépôt ) are also collected in the following table.

[0198] [Tables4] Reference 1 Reference 2 II (ref + 1% spiroboronate) 12 (ref 2 + 1% spiroboronate) MCT at 3 times 90 min^* ND 3.3 5.7 6.1 TDépôt (V) ND 235 249 243 (,) Values are expressed with a standard deviation of ± 1%

[0199] These results show that lubricants supplemented with a spiroboronate retain improved thermal stability, even for a duration of exposure to high temperature conditions three times longer.

[0200] These results are confirmed by temperatures from which the formation of deposits occurs for the compositions according to the invention which are much higher than those obtained with the reference lubricants.

[0201] Thus, the lubricants according to the invention retain excellent detergency properties even after repeated use of the lubricant.

Claims

1.

2.

3.

4.

5.

6. Claims Use, as a detergent additive in a lubricating composition intended for a motorization system, of at least one spiro compound of the following formula (I): in which M is an atom chosen from boron and aluminum; ni and n2 are, independently of each other, 0, 1 or 2; and R represent, independently of one another, a hydrocarbon group comprising from 1 to 50 carbon atoms, in particular from 5 to 15 carbon atoms. Use according to the preceding claim, said spiro compound being of formula (I) in which the substituents R represent, independently of one another, an aliphatic chain, linear or branched, in particular an alkyl chain, preferably linear, of C1 to C50; in particular of C3 to C30, in particular of C5 to C23 and more particularly of C8 to C15, more preferably of C10. Use according to claim 1 or 2, said spiro compound being of formula (I) in which n1 and n2 are 1, the R groups being identical. Use according to any one of the preceding claims, said spiro compound being of formula (I) in which M is a boron atom. Use according to any one of the preceding claims, said spiro compound(s) being used in a content of between 0.1 and 20% by mass relative to the total mass of said lubricating composition, preferably of between 0.2 and 15% by mass, more preferably between 0.5 and 10% by mass, and more preferably between 0.5 and 5.0% by mass. Use according to any one of the preceding claims, said lubricating composition comprising at least one detergent additive me- metal, distinct from the spiro compound of formula (I), chosen from salts of alkali metals or alkaline earth metals, overbased or not, in particular from calcium salts, magnesium salts and their mixtures.

7. Use according to the preceding claim, said metallic detergent additive(s) being present in a content of less than or equal to 15% by mass, in particular less than or equal to 10% by mass and more particularly between 0.5% and 5.0% by mass, relative to the total mass of said composition.

8. Use according to any one of the preceding claims, said composition comprising one or more base oils in a content of at least 50% by mass, relative to its total mass, in particular at least 60% by mass, more particularly ranging from 60 to 99% by mass and preferably from 70 to 90% by mass.

9. Use according to any one of the preceding claims, said composition comprising one or more other additives, distinct from said spiro compound(s), chosen from friction modifying additives, anti-wear additives, extreme pressure additives, antioxidants, viscosity index improvers, pour point lowering additives, dispersants, anti-foaming agents, thickeners, corrosion inhibitors, and mixtures thereof.

10. Use according to any one of the preceding claims, said lubricating composition being a lubricant for a motorization system, mobile or stationary, comprising a Diesel, gasoline, gas or dual-fuel engine, in particular in a light or heavy motor vehicle.

11. Use according to any one of the preceding claims, for preventing and / or reducing abnormal fuel combustion, in particular pre-ignition, in particular LSPI, and / or knocking, in an engine system lubricated using said lubricating composition.

12. Lubricating composition intended for the lubrication of a motorization system, comprising at least: - one or more base oils; - at least one spiro compound of formula (I) defined in any one of claims 1 to 5, - optionally one or more additives, distinct from said spiro compound(s), chosen from other detergent additives, in par- in particular metallic detergent additives, friction modifiers, anti-wear additives, extreme pressure additives, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, antifoam agents, thickeners, corrosion inhibitors, and mixtures thereof.

13. Lubricating composition according to the preceding claim, said composition comprising at least one metallic detergent additive distinct from the spiro compound of formula (I), in particular chosen from calcium and magnesium salts and their mixtures; in particular in a content less than or equal to 15% by mass, in particular less than or equal to 10% by mass and more particularly between 0.5% and 5.0% by mass, relative to the total mass of said composition.

14. Method for lubricating a motorization system, comprising a step of bringing at least one mechanical part of said system into contact with a lubricating composition as defined according to claim 12 or 13, said motorization system comprising in particular a Diesel, gasoline, gas or dual-fuel engine, more particularly in a light or heavy motor vehicle.

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