5w-grade lubricant compositions comprising a re-refined oil

Abstract

The present invention relates to a lubricating composition of grade 5W as defined by the SAE J300 standard, said lubricant composition comprising one or more at least partially re-refined base oils and at least one polyol triester obtained by reaction between a polyol and one or more acids, said polyol comprising at least 3 hydroxyl functions.

Description

[0001] 5W GRADE LUBRICANT COMPOUNDS INCLUDING REFINED OIL

[0002] The present invention relates to 5W grade lubricating compositions, comprising at least one re-refined oil, and their uses, in particular for lubricating engine parts.

[0003] Lubricating compounds, also known as "lubricants," are commonly used in various components of motor vehicles primarily to reduce friction between the moving metal parts within these components, particularly the engine, transmission, and hydraulic system. They are also effective in preventing premature wear and even damage to these parts, especially their surfaces. To achieve this, a lubricating compound typically consists of a base oil, to which several additives are generally added. These additives are designed to enhance the lubricating performance of the base oil, such as friction modifiers, and also to provide additional performance benefits.

[0004] Internal combustion engines generate CO2 during operation due to the combustion of the fuel they use. Current environmental concerns, particularly regarding the reduction of carbon dioxide emissions, create an urgent need for alternative lubricant compositions to reduce their carbon footprint.

[0005] Furthermore, it is important that these alternative compositions have technical performance at least equivalent to, or even superior to, the compositions used to date, for example with regard to detergency properties.

[0006] Therefore, there is a need for lubricating compositions that reduce the carbon footprint while offering satisfactory or even improved technical properties.

[0007] The present invention aims precisely to provide new lubricating compositions for the lubrication of engine systems, particularly in vehicles, enabling optimal cold-weather performance while reducing carbon footprint. To this end, the invention relates to a 5W grade lubricant composition according to the SAE J300 classification, said lubricant composition comprising one or more base oils, at least partially re-refined, and at least one polyol triester obtained by reaction between a polyol and one or more acids, said polyol comprising at least three hydroxyl groups.

[0008] Surprisingly, as can be seen from the examples that follow, the inventors discovered that the use of a base oil at least partly re-refined in combination with a polyol triester obtained by reaction between a polyol and one or more acids, said polyol comprising at least 3 hydroxyl functions, makes it possible to obtain a composition meeting the specifications required for cold performance, while also making it possible to obtain a satisfactory carbon footprint.

[0009] In particular, the inventors have observed that the use of a specific polyol triester makes it possible to counteract the unsatisfactory cold properties usually obtained with regenerated base oils.

[0010] Surprisingly, the composition of the invention makes it possible to obtain both better performance in terms of eco-design (in particular in comparison with a composition including native oils) and a level of technical performance at the level required for the 5W grade, in particular in terms of CCS viscosity and Noack volatility.

[0011] According to one embodiment, the polyol used in the compositions according to the invention is a triol or a tetraalcohol, preferably a triol.

[0012] In particular, the polyol can be a triol or a tetraalcohol, saturated or unsaturated, linear or branched, in C1 to C16.

[0013] According to one embodiment, the polyol triester of the compositions of the invention is obtained by reaction between a polyol comprising at least 3 hydroxyl functions, and one or more carboxylic acids, in C2 to C30, preferably in C6 to C20.

[0014] Preferably, the polyol triester is a triol triester formed between a triol, saturated or unsaturated, linear or branched, in positions C1 to C16, and one or more monocarboxylic acids, saturated, linear or branched, in positions C2 to C30, preferably from C6 to C20. According to one embodiment, the polyol triester is a triol triester formed between trimethylolpropane and monocarboxylic acids, saturated, linear or branched, in positions C2 to C30, preferably from C6 to C20.

[0015] According to one embodiment, the lubricating composition according to the invention comprises from 5% to 50% by mass, preferably from 10% to 30%, preferably from 15% to 25%, by mass of polyol triester relative to the total mass of said lubricating composition.

[0016] According to one embodiment, the lubricating composition according to the invention comprises from 40% to 90% by mass, preferably from 45% to 80%, preferably from 50% to 70%, by mass of base oil(s) at least partly re-refined relative to the total mass of said lubricating composition.

[0017] According to one embodiment, in the lubricating composition according to the invention, the base oil, at least partly re-refined, is or are the base oils, at least partly refined, from a used lubricant that has been subjected to one or more prior steps of dehydration, distillation, filtration, hydrogenation, liquid / liquid extraction, decantation and / or passing the used lubricant over an adsorbent material.

[0018] According to one embodiment, the base oil or oils at least partially re-refined have a sulfur content of between 0.01% and 0.2% by mass, relative to the total mass of said oil or base oils at least partially re-refined, and / or in which the base oil or oils at least partially re-refined have an aromatic compound content of more than or equal to 0.5% by mass, in particular more than or equal to 1% by mass, in particular between 1% and 25% by mass, more particularly between 2.5% and 20% by mass, relative to the total mass of said oil or base oils at least partially re-refined.

[0019] According to one embodiment, the base oil or oils, at least partly re-refined, have an alkylphenol content of 5 to 3,200 ppm, preferably 10 to 2,000 ppm, and preferably 15 to 1,500 ppm.

[0020] Preferably, the lubricating composition according to the invention further comprises one or more base oils distinct from the base oil or oils at least partly re-refined and / or one or more additives, in particular selected from friction modifier additives, anti-wear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD) additives, dispersants, anti-foaming agents, thickeners, corrosion inhibitors, copper passivating agents, emulsifiers, and mixtures thereof.

[0021] The present invention also relates to the use of a lubricating composition as defined above, for the lubrication of an engine.

[0022] The present invention also relates to the use of a lubricating composition as defined above, to reduce the carbon footprint.

[0023] The present invention also relates to the use of a polyol triester obtained by reaction between a polyol and one or more acids, said polyol comprising at least 3 hydroxyl functions, in a lubricating composition comprising at least one base oil at least partly re-refined, to reduce the carbon footprint of said lubricating composition, the polyol triester being in particular as defined above and the base oil at least partly re-refined being in particular as defined above.

[0024] Other characteristics and variations of the lubricating composition according to the invention will become clearer from the description and examples that follow, given by way of illustration and not limitation of the invention.

[0025] In the following text, the expressions "between ... and ...", "from ... to ...", "ranging ... to ..." and "varying from ... to ..." are equivalent and are meant to mean that the boundaries are included, unless otherwise stated.

[0026] Unless otherwise indicated, the expression "containing one" should be understood as "containing at least one".

[0027] As stated above, the lubricating composition according to the invention comprises at least one base oil, at least partially re-refined, and at least one polyol triester obtained by reaction between a polyol and one or more acids, said polyol comprising at least 3 hydroxyl functions.

[0028] The lubricating composition according to the invention is a 5W winter grade oil.

[0029] According to one embodiment, the lubricating composition according to the invention has a kinematic viscosity at 100°C, measured according to ASTM D445, greater than or equal to 9 mm 2 / s, in particular greater than or equal to 9.3 mm 2 / s, including 9.3 mm 2 / s at 12.5 mm 2 / s, preferably 10 mm 2 / s at 12.5 mm 2 / s.

[0030] According to one embodiment, the Noack volatility, determined according to CEC L-40-93, of the lubricating composition according to the invention is less than 12%. The Noack volatility of the lubricating composition corresponds to the Noack volatility at 250°C, measured according to CEC L-40-A-93 method.

[0031] According to one embodiment, the aforementioned lubricating composition has a viscosity at 150°C and under constant shear (or HTHS 150) greater than or equal to 2.9 mPa.s, preferably from 3.0 mPa.s to 5.0 mPa.s, and in particular from 3.1 mPa.s to 2.9 mPa.s.

[0032] HTHS viscosity (High Temperature, High Shear) is a measure of the viscosity of the residual oil film under high stress (mechanical shear pressure) at high temperature. Here, the HTHS viscosity value of 150 is measured at 150°C.

[0033] These values ​​are measured according to CEC L-036-90 or ASTM D4683 standards.

[0034] According to one embodiment, the aforementioned lubricating composition has a CCS dynamic viscosity at -30°C of less than 6600 mPa.s measured according to ASTM D5293.

[0035] Preferably, the above-mentioned lubricating composition has a CCS dynamic viscosity at -30°C of 4,500 mPa.s to 6,600 mPa.s, preferably of 4,600 mPa.s to 6,000 mPa.s, measured according to ASTM D5293.

[0036] polyol triester

[0037] As stated above, the lubricating composition according to the invention comprises at least one polyol triester obtained by reaction between a polyol and one or more acids, said polyol comprising at least 3 hydroxyl functions.

[0038] Preferably, the polyol has a hydrocarbon chain, linear or branched, comprising from 1 to 30 carbon atoms, more preferably comprising from 3 to 25 carbon atoms, even more preferably from 3 to 18 carbon atoms.

[0039] According to one embodiment, the polyol has a hydrocarbon chain, linear or branched, preferably branched, comprising from 3 to 10 carbon atoms.

[0040] According to one embodiment, the polyol is a triol or a tetraalcohol, preferably a triol.

[0041] In one embodiment, the polyol triester of the compositions of the invention is a triol triester obtained by reaction between a triol and one or more acids. In another embodiment, the polyol is a triol or a tetraalcohol, saturated or unsaturated, linear or branched, with a C1 to C16 structure.

[0042] Preferably, the polyol is a triol, saturated or unsaturated, linear or branched, comprising from 1 to 16 carbon atoms, preferably from 3 to 12 carbon atoms, and even better from 4 to 6 carbon atoms.

[0043] Advantageously, the polyols are chosen from erythritol, trimethylolpropane, pentaerythritol, preferably trimethylolpropane or dipentaerythritol.

[0044] Preferably, the polyol is trimethylolpropane.

[0045] Within the framework of the present invention, the acid or acids from which a polyol ester according to the invention is formed can be chosen from monoacids (also called monocarboxylic acids) and polyacids (also called polycarboxylic acids).

[0046] By "polyacid" we mean an acid bearing at least 2 carboxylic acid functions, preferably comprising between 2 and 6 carboxylic acid functions, more preferably between 2 and 4 carboxylic acid functions.

[0047] Preferably, the acids are chosen from acid anhydrides or fatty acids.

[0048] Advantageously, the acid anhydrides are chosen from ethanoic anhydrides, propanoic anhydrides, maleic anhydrides, phthalic anhydrides, cis-1,2,3,6-tetrahydrophthalic anhydrides and succinic anhydrides.

[0049] Advantageously, fatty acids comprise from 4 to 36 carbon atoms, preferably from 6 to 24 carbon atoms. These fatty acids can be saturated, monounsaturated, and / or polyunsaturated. The number of carbon atoms also includes the carbon atoms of the carboxylic acid group(s).

[0050] According to a particular embodiment of the invention, the fatty acids used for the reaction with the alcohols are, for example, fatty acids derived from vegetable oil and can be saturated, mono- and / or polyunsaturated. They are chosen for example from caprylic, pelargonic, capric, undecylenic, lauric, tridecylenic, myristic, pentadecylic, palmitic, margaric, stearic, nonadecyl, arachic, heneicosanoic, behenic, tricosanoic, lignoceric, pentacosanoic, cerotic, heptacosanoic, montanic, nonacosanoic, melissic, hentriacontanoic, laceroic acids, and their derivatives or unsaturated fatty acids such as palmitoleic, oleic, erucic, nervonic, linoleic, α-linolenic, β-linolenic, β-linolenic, β-homo-β-linolenic, arachidonic, eicosapentaenoic, docosahexaenoic acids, and their derivatives.Preferably, the fatty acids are derived from the hydrolysis of triglycerides present in vegetable and animal oils, such as coconut, palm, olive, peanut, rapeseed, sunflower, soybean, castor, wood, corn, pumpkin, grapeseed, jojoba, sesame, walnut, hazelnut, almond, shea, macadamia, alfalfa, rye, safflower, coconut, cottonseed, flaxseed, beef tallow, or any mixture thereof. Natural oils may have been genetically modified to enrich their content of certain fatty acids, for example, high-oleic rapeseed or sunflower oil.

[0051] In a particular embodiment of the invention, the carbon chain of acid anhydrides or fatty acids can be functionalized by one or more groups selected from carboxylic acids, amides, ureas, urethanes, amines, polyisobutadienes or alcohols.

[0052] The polyol(s) esters implemented according to the invention can be mixed esters, that is to say esters obtained by mixing different alcohols and / or different acids.

[0053] Thus, preferably, the polyol(s) esters used according to the invention are obtained by reaction between one or more polyol(s) as defined above and one or more monoacid(s) or polyacid(s) as defined above.

[0054] According to one embodiment, the polyol triester according to the invention is obtained by reaction between a polyol comprising at least 3 hydroxyl functions, and one or more carboxylic acids, in C2 to C30, preferably in C6 to C20.

[0055] According to one embodiment, the polyol triester according to the invention is obtained by reaction between a polyol comprising at least 3 hydroxyl functions, and one or more saturated, linear or branched carboxylic acids, in C2 to C30, preferably in C6 to C20.

[0056] By "Cn carboxylic acid", we mean a carboxylic acid comprising a total of n carbon atoms, therefore also including the carbon atom of the carboxylic acid function or carboxylic functions when it is a polycarboxylic acid.

[0057] According to one embodiment, the polyol triester according to the invention is a triol triester formed between a triol, saturated or unsaturated, linear or branched, in C1 to C16, and one or more (mono)carboxylic acid(s), saturated, linear or branched, in C2 to C30, preferably in C6 to C20.

[0058] According to one embodiment, the polyol triester according to the invention is a triol triester formed between a triol, saturated or unsaturated, linear or branched, in C1 to C16, and one or more monocarboxylic acid(s), saturated, linear or branched, in C6 to C20.

[0059] Preferably, the polyol triester is a triol triester formed between trimethylolpropane and monocarboxylic acid(s), saturated, linear or branched, in C6 to C20.

[0060] According to one embodiment, the lubricating composition according to the invention comprises from 5% to 50% by mass, preferably from 10% to 30%, preferably from 15% to 25%, by mass of polyol triester relative to the total mass of said lubricating composition.

[0061] Base oil(s) at least partially re-refined

[0062] The lubricating composition according to the invention comprises at least one base oil, at least partially re-refined.

[0063] The lubricating composition according to the invention may comprise a single base oil at least partly re-refined or a mixture of several base oils at least partly re-refined.

[0064] According to one embodiment, the lubricating composition comprises a mixture of base oils, in which at least one of the base oils of said mixture is at least partially re-refined.

[0065] Preferably, the base oil blend consists solely of base oils that are at least partially re-refined.

[0066] According to one embodiment, the lubricating composition according to the invention does not include unrefined base oil, namely does not include conventional unrecycled base oil (or new base oil).

[0067] In the context of the present invention, the expression "base oil at least partly re-refined", also referred to more simply in the following text as "re-refined lubricating oil", "re-refined oil", "regenerated oil" or "recycled oil", designates an oil derived at least partly from a used lubricating composition that has been subjected to one or more treatment steps known as re-refining treatment.

[0068] According to the invention, the term "used lubricating composition" (or more simply "used lubricant" or "used lubricating oil") means any lubricating composition that has been used for the lubrication of moving parts, in particular metal parts, of a mechanical system, such as, but not limited to, bearings, gears or motors.

[0069] Used lubricating oil can come from various sources. In particular, as detailed later in the text, it can be a lubricant that has been used to lubricate a motorization system, especially a "mobile" one, or to lubricate an industrial system, especially a "stationary" one.

[0070] Due to their origin, used lubricating oils, particularly engine lubricating oils, contain a number of degradation products derived from the oil itself or the additives it contains, as well as metal particles, metal oxides, and other elements, originating, for example, from the engine. Used oil may contain, in particular, high levels of undesirable elements, such as calcium (Ca), iron (Fe), magnesium (Mg), sodium (Na), nickel (Ni), phosphorus (P), silicon (Si), chlorine (Cl), zinc (Zn), oxygen (O), or nitrogen (N), etc.

[0071] Methods for re-refining or reconditioning used lubricating oils have been developed, in order to regenerate these oils and allow their subsequent reuse.

[0072] A re-refined lubricating oil is thus an oil obtained after one or more processing steps of a used lubricant, aimed at eliminating, at least in part, a number of contaminating elements present in it, such as dust, water, fuel fractions, metallic elements and other residues resulting from the degradation of additives present in the lubricant.

[0073] According to one embodiment, a re-refined lubricating oil according to the present invention comprises one or more alkylphenols. "Alkylphenol" is understood to mean a phenolic compound with an alkyl group Ri in the para position, and therefore with the formula R1-C6H4-OH. The presence of alkylphenols is characteristic of re-refined lubricating oils, since native (unused) oils do not contain alkylphenols.

[0074] Preferably, the alkylphenol content in the re-refined lubricating oil according to the present invention is from 5 to 3,200 ppm. A re-refined lubricating oil according to the present invention may, for example, comprise from 10 to 2,000 ppm, preferably from 15 to 1,500 ppm, of alkylphenol(s).

[0075] According to one embodiment, a re-refined lubricating oil according to the present invention comprises 10 to 300 ppm, preferably 15 to 250 ppm, of alkylphenol(s).

[0076] According to one embodiment, a re-refined lubricating oil according to the present invention comprises 150 to 2,000 ppm, preferably 200 to 1,500 ppm, of alkylphenol(s).

[0077] The alkylphenol(s) content in the re-refined lubricating oil is measured according to the method described in the patent application filed under number FR 23 15133.

[0078] This method is based on the implementation of liquid chromatography and mass spectrometry steps, using a standard compound which is 4-hexadecylphenol.

[0079] For the liquid chromatography steps, a column packed with particles composed of C8-bonded silica is used. Measurements are carried out at 40°C with a flow rate of 0.4 mL / min.

[0080] Here, we use a reversed-phase column to separate the different components of the sample (in this case, re-refined lubricating oil to be analyzed) according to their polarity. We manipulate the composition of the mobile phase to modify these interactions over time and thus progressively elute the different molecules of the analyzed sample (here, re-refined lubricating oil).

[0081] The mobile phase is used in the form of a gradient as shown in Table 1 below, from a solution A comprising 50% water and 50% acetonitrile and a solution B comprising 100% methanol.

[0082] [Table 1]

[0083] Using mass spectrometry detection, it is then possible to obtain the signal produced only by the molecules of interest, identified by both their mass and their retention time.

[0084] The ionization source used is preferably an electrospray ionization (ESI) source, which allows for the selective ionization of polar compounds. In the case of the method used here, the detection mode chosen is negative detection mode because it allows for the selective ionization of polar compounds with acidic characteristics. The mass range (m / z) varies from 100 to 1200.

[0085] In particular, the method for measuring the alkylphenol content in re-refined lubricating oil used according to the invention includes a first step consisting of preparing the standard solution (4-hexadecylphenol) and the solution to be analyzed (re-refined lubricating oil):

[0086] . preparation of a standard solution at different concentrations to obtain a calibration curve as explained later, by dilution in THF with the addition of 2% ammonium hydroxide; and

[0087] . preparation of a solution of said re-refined lubricating oil by dilution in THF with the addition of 3% ammonium hydroxide.

[0088] To establish the calibration curve, the intensity of the chromatographic peak associated with the 4-hexadecylphenol ion of the standard is retrieved by plotting an extracted ion chromatogram (EIC). This allows for an extracted chromatogram only for a given m / z ratio, in this case 317.28 for the standard molecule, the deprotonated form corresponding to the [C22H38O-H] ion. The intensity of the EICs is therefore retrieved for each analysis at the different concentrations tested.

[0089] The data obtained allow the construction of the calibration curve. This calibration curve is obtained by injecting several standard solutions at different concentrations: the line is constructed by linear regression, and the correlation coefficient (R) is calculated. 2) allows verification of detector linearity and correct preparation of standard solutions.

[0090] The associated equation then allows us to predict the concentration of an unknown sample by entering the experimentally obtained y value. Here, the equation is as follows: y = 1001.9x - 15309

[0091] To quantify alkylphenols in the re-refined lubricating oil according to the invention, the analytical method includes a step of identifying the m / z ratios of alkylphenol residues on the average mass spectrum by integrating the entire chromatogram. This average spectrum corresponds to the average of all the mass spectra obtained during the complete chromatographic run. This allows for the identification of all the compounds that were ionized during the analysis. From this average mass spectrum, a mass list is extracted, grouping all the m / z ratios of the ions with their associated intensities.

[0092] The next step is to construct a Kendrick diagram using this mass list. This is a molecular mapping technique that allows for the identification of series of compounds of the same type but with different degrees of alkylation, thus eliminating the mass defect of the hydrogens in the CH2 motif.

[0093] The Kendrick diagram can be created by calculating the following values: 14.00000

[0094] KM = mass (IUPAC or EXPER) x - — k 7 14.01565 where KM corresponds to the Kendrick mass, IUPAC mass corresponds to the theoretical mass calculated from the sum of each element constituting the molecule of interest, here for the standard molecule hexadecylphenol with the formula C22H37O the IUPAC mass = 317.284440 g.mol -1 , and EXPER mass corresponds to an experimental mass measurement, measured during an experiment.

[0095] The Kendrick mass KM is calculated for each peak of the mean mass spectrum, determined beforehand as explained above.

[0096] Next, the Kendrick MKD mass defect is typically calculated using the following equation:

[0097] KMD = NKM - KM where KMD corresponds to the Kendrick mass fault,

[0098] KM corresponds to Kendrick's mass, and

[0099] NKM is rounded to the nearest integer of the mass of Kendrick KM.

[0100] The Kendrick KMD mass defect is calculated for each peak (each peak corresponding, for example, to a compound present in the re-refined lubricating oil).

[0101] Kendrick diagrams are a 2D molecular map representing KMDs as a function of NKMs. Homologous compounds varying in their degree of alkylation appear as horizontal lines.

[0102] The complete m / z set of alkylphenols is obtained by applying a filter to the y-axis (KMD): this corresponds to the KMD value of 0.069. Once all the m / z values ​​with KMD = 0.069 are identified, they are used to construct extracted ion chromatograms (EICs) as described for the standard molecule. This allows for a chromatogram dependent solely on the required m / z value. The EIC intensities for each m / z corresponding to the alkylphenols are then summed to obtain the total intensity (several alkylphenol-type molecules are obtained from the spectra of re-refined lubricating oil according to the invention, these molecules varying in the length of their alkyl chain).

[0103] To obtain a quantification, the sum of the intensities of the obtained EICs is used as the y-value for the calibration curve equation. For example, if the value obtained is 2.45 E6. The quantification of alkylphenol residues in the re-refined lubricating oil used according to the invention is: y = 1001.9% - 15309

[0104] > y + 15309

[0105] X ~ 1001.9 and therefore x is equal to 2460.6 ppm.

[0106] According to one embodiment, a re-refined lubricating oil according to the present invention comprises one or more polyalphaolefins (PAOs). The presence of polyalphaolefin(s) is characteristic of re-refined lubricating oils, since native (unused) oils do not contain polyalphaolefins (PAOs).

[0107] Figures 1 and 2 show two-dimensional chromatograms of two re-refined lubricating oils according to the present invention. The arrow in each figure indicates the characteristic PAO peak (at C30), a marker of the re-refined oils.

[0108] According to one embodiment, a re-refined lubricating oil according to the present invention comprises one or more polyalphaolefins (PAOs) comprising less than 40 carbon atoms, and preferably comprising 30 carbon atoms.

[0109] The presence of PAO in re-refined lubricating oil is determined according to the method described in the patent application filed under number FR 24 06231.

[0110] This method is based on the implementation of comprehensive two-dimensional gas chromatography (GCxGC) and classification steps.

[0111] In particular, it is implemented via a chromatography device, the chromatography device comprising a comprehensive two-dimensional gas chromatography module including a first column A and a second column B, and capable of separating different compounds of the product according to their volatility and polarity, the chromatography device further comprising a flame ionization detector capable of measuring an intensity of ionization electric current generated for each compound included in the product, the chromatography device being calibrated with at least one calibration product, allowing the retention time of the different compounds present in the product to be corrected.

[0112] The method is further implemented by an electronic classification device, comprising the following steps: a. determine a table describing the intensity of ionization electric current generated for each compound included in the product as a function of the corrected retention times in columns A and B, from a measurement carried out by the chromatography device on the product; b. assign a class to the product, from among a plurality of classes, by applying a multivariate statistical algorithm to the table, said algorithm being trained on tables obtained from reference products.

[0113] The chromatography device includes a comprehensive two-dimensional gas chromatography module comprising a first column A and a second column B. The comprehensive two-dimensional gas chromatography modules (2DGC or GCxGC) that may be used in the context of this disclosure are those described in the literature.

[0114] These modules generally include an injection module, a vaporization module, a first column A, a modulator, and a second column B. They allow two-dimensional separation of complex mixtures, because the product is subjected to two separations, resulting in a two-dimensional chromatogram as a function of the retention times of columns A and B and a table describing the intensity of the ionization electric current generated for each compound included in the product as a function of the corrected retention times in columns A and B.

[0115] In one embodiment, the first column A and the second column B are polydimethylsiloxane columns partially functionalized with phenyl groups. The percentage of phenyl functionalization can range from 2% to 50%. In a particular embodiment, the percentage of phenyl functionalization in column A is greater than the percentage of phenyl functionalization in column B. Advantageously, the length of column A is greater than that of column B. The diameters of the two columns, A and B, can be equivalent. Both columns can have a film thickness of 0.1 µm, suitable for separating low-volatility samples. In one embodiment, the temperature gradient applied to the furnace is 2°C / min up to 400°C.A quantity of product is injected into the first column A to obtain an initial separation, and then, via the modulator, into the second column B to obtain a second separation. The product can be injected directly without pretreatment, particularly in the case of lubricating oil analysis.

[0116] The GCxGC device is coupled to a flame ionization detector (FID). This detector is capable of measuring the intensity of the ionization current generated for each compound in the product. The flame ionization detector is located at the outlet of the second column.

[0117] Following analysis by the flame ionization detector, a table describing the intensity of the ionization current generated for each compound in the product, as a function of the corrected retention times in columns A and B, is determined. The table is therefore derived from a two-dimensional chromatogram obtained from a measurement performed by the chromatography device on the product.

[0118] In addition, during this initial step, an external calibration is performed to correct the retention time of the various compounds present in the product. This is done by injecting at least one calibration product. If the product to be classified is a lubricating oil, the calibration product can be a lubricating oil, preferably recycled. In one embodiment, the calibration product comprises at least one marker, preferably at least two markers. The marker can be selected from n-paraffins, polyalphaolefins, and mixtures thereof. The retention time correction can be performed using software.

[0119] Following this initial step, the classification system moves to a subsequent step, during which it assigns, via its product assignment module, a respective class from among the plurality of classes, by applying a multivariate statistical algorithm to the table, said algorithm being trained on tables obtained from reference products.

[0120] The multivariate statistical algorithm used in the allocation step can be a partial least squares regression algorithm; preferably, the multivariate statistical algorithm is chosen from the group consisting of: a partial least squares regression algorithm, and a partial least squares regression algorithm with discriminant analysis. The algorithm is typically a partial least squares regression algorithm, such as the PLS algorithm or the PLS-DA algorithm.

[0121] The multivariate statistical algorithm used in the allocation step is trained on tables obtained from reference products. In Partial Least Squares Discriminant Analysis (PLS-DA), the prediction coefficient on a scale of 0 to 1 represents the probability or confidence level of a sample belonging to a particular class.

[0122] Here's how this coefficient is calculated and used:

[0123] 1. Creation of latent variables:

[0124] PLS-DA creates latent variables (components) that capture the maximum variance of the X data (the predictors) while maximizing the covariance with the Y classes (the categorical responses).

[0125] 2. Calculating scores:

[0126] The samples are projected onto these latent variables, producing scores that are used to discriminate between classes.

[0127] 3. Modeling:

[0128] A linear model is fitted to these scores to predict the values ​​of Y. In the case of PLS-DA, Y is often coded in binary to represent the classes (e.g., 0 for group A and 1 for group B).

[0129] 4. Prediction:

[0130] When making predictions for new samples, the scores of these samples are calculated and passed through the linear model to obtain a continuous prediction. This continuous prediction is then transformed into a probability on a scale of 0 to 1.

[0131] 5. Interpretation of probabilities:

[0132] These probabilities are then interpreted to assign the samples to the different classes.

[0133] For example :

[0134] - If the probability is less than 0.4, the sample is classified in group A (here, the group of re-refined base oils); and

[0135] - If the probability is greater than or equal to 0.4, the sample is classified in group B (group of conventional base oils).

[0136] According to one embodiment, in the lubricating composition according to the present invention, the content of base oil(s), at least partially re-refined, is at least 50% by mass, preferably at least 60%, preferably from 65% to 95%, or even from 70% to 90%, or from 75% to 80%, relative to the mass of said lubricating composition. According to another embodiment, in the lubricating composition according to the invention, said base oil(s), at least partially re-refined, represent more than 40% by mass, in particular more than 45% or more than 50% by mass, and more particularly from 50% to 70% by mass, relative to the total mass of said lubricating composition.

[0137] According to one embodiment, the mass content of base oil(s) at least partly re-refined is between 50% and 90%, and preferably between 70% and 85%, relative to the total mass of said lubricating composition.

[0138] As detailed later in the text, the re-refined lubricating oil(s) can be used as the sole base oil(s), that is, without the addition of a separate base oil, such as new base oil. Alternatively, they can be used in combination with at least one new base oil.

[0139] In a particular embodiment, the lubricating composition consists solely of one or more re-refined lubricating oils.

[0140] According to one embodiment, the base oil or oils, at least partially re-refined, have a kinematic viscosity measured at 100°C according to ASTM D445 greater than or equal to 3.0 mm 2 / s, in particular greater than or equal to 4.0 mm 2 / s, specifically between 4.0 and 12 mm 2 / s, in particular greater than or equal to 4.3 mm 2 / s and more specifically between 4.4 and 10 mm 2 / s, particularly between 4.5 and 6 mm 2 / s.

[0141] According to one embodiment, the base oil or oils, at least partly re-refined, have a viscosity index, determined according to ASTM D2270, greater than or equal to 110, in particular between 110 and 130, preferably between 112 and 125, and more particularly between 118 and 124.

[0142] The viscosity index is calculated by measuring the kinematic viscosity at 40°C and 100°C. These measurements are then compared to the results of two reference oils. The calculation method is described in ASTM D2270.

[0143] Preferably, the re-refined lubricating oils implemented according to the invention advantageously exhibit, compared to virgin base oils of equivalent group according to the API classification, reduced volatility.

[0144] Volatility properties can be more specifically evaluated by determining the Noack volatility according to CEC L-40-93. Advantageously, a regenerated lubricating oil implemented according to the invention has a Noack volatility less than or equal to 15%, in particular less than or equal to 14%.

[0145] More preferably, a regenerated lubricating oil implemented according to the invention can have a Noack volatility strictly less than 12%, in particular between 7% and 11%.

[0146] According to one embodiment, the base oil or oils at least partly re-refined have a sulfur content of between 0.01% and 0.2% by mass, relative to the total mass of said oil or base oils at least partly re-refined.

[0147] The content of this element can be assessed by any method known to a person skilled in the art, for example by X-ray fluorescence (XRF).

[0148] According to one embodiment, the base oil or oils, at least partially re-refined, have an aromatic compound content of 0.5% or more by mass, in particular 1% or more by mass, in particular between 1% and 25% by mass, more particularly between 2.5% and 20% by mass, relative to the total mass of said oil or base oils, at least partially re-refined.

[0149] Preferably, in the lubricating composition of the invention, the base oil or oils, at least partially re-refined, have an aromatic compound content of between 4% and 15% by mass, in particular between 5% and 10% by mass, relative to the total mass of said oil or base oils, at least partially re-refined.

[0150] The levels of these different elements can be determined by any method known to a person skilled in the art, for example by X-ray fluorescence (XRF) or by infrared or ultraviolet spectroscopy.

[0151] According to one embodiment, the lubricating composition according to the invention further comprises one or more base oils distinct from the base oil, at least partially re-refined, and / or one or more additives, in particular selected from friction modifier additives, anti-wear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD) additives, dispersants, anti-foaming agents, thickeners, corrosion inhibitors, copper passivating agents, emulsifiers, and mixtures thereof.

[0152] As previously stated, the base oil used in the lubricating compositions of the invention is a lubricating oil that is at least partly re-refined, also called "regenerated oil" or "recycled oil", in other words a lubricating oil derived from a used lubricating composition that has been subjected to one or more re-refining treatment steps.

[0153] It is understood that a used lubricating composition may be a mixture of several used lubricating compositions, from the same source or from several different sources.

[0154] Used lubricating compositions and, consequently, regenerated lubricating oils, comprise, in majority quantity, one or more base oils conventionally used in the field of lubricants, such as mineral, synthetic or natural, animal or vegetable oils or mixtures thereof.

[0155] It can be a mixture of several base oils, for example a mixture of two, three, or four base oils.

[0156] These base oils can be of natural origin, for example from plants or animals, such as vegetable oils, animal oils, fish oils, and mixtures thereof. Examples of such oils are rapeseed oil, canola oil, tall oil, sunflower oil, soybean oil, hemp oil, olive oil, linseed oil, mustard oil, palm oil, peanut oil, castor oil, coconut oil, animal fats, and mixtures thereof.

[0157] Advantageously, these base oils are mineral or synthetic oils belonging to groups I to V according to the classes defined in the API classification (or their equivalents according to the ATI EL classification) and presented in Table 2 below, or mixtures thereof. [Table 2]

[0158] In particular, the used lubricating composition, from which the regenerated lubricating oil implemented according to the invention is derived, may comprise at least 50% by weight of base oil(s) relative to its total weight, in particular at least 60% by weight of base oil(s), and more particularly between 60% and 99% by weight of base oil(s).

[0159] According to a particular embodiment, the re-refined lubricating oil implemented according to the invention can be derived from the treatment of a used lubricating composition that has been used for the lubrication of a motorization system, in particular "mobile", i.e. including light vehicles, heavy goods vehicles, mobile machines known as "off road", or even marine vehicles.

[0160] According to another particular embodiment, the re-refined lubricating oil implemented according to the invention can be obtained from the treatment of a used lubricating composition that has been used for the lubrication of an industrial system, in particular a "stationary" one, i.e. including, but not limited to, turbines, compressors, hydraulic systems, gears, or even forming or cutting machines.

[0161] A used lubricating composition, from which the regenerated lubricating oil used according to the invention is derived, may contain various conventional additives in the field of lubricants, such as friction modifiers, extreme pressure additives, anti-wear additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD) additives, dispersants, anti-foaming agents, thickeners, emulsifiers, and mixtures thereof.

[0162] As previously mentioned, the properties of the used lubricant composition are degraded due to its use, for a more or less long period, for the lubrication and / or cooling of a mechanical system, in particular a motorization system, such as a combustion engine.

[0163] Due to their origin, used lubricating compositions may contain one or more of the additives described above and impurities resulting from the degradation of additives originally present in the lubricant, or resulting from the wear of moving mechanical parts.

[0164] The composition of used lubricant can of course be different depending on the origin of the lubricant, its initial formulation and the fact that it may have been contaminated differently depending on its use.

[0165] The regenerated lubricating oil implemented according to the invention comes more particularly from a used lubricant which has been subjected to one or more prior pre-treatment steps known in the field of re-refining used lubricants.

[0166] In particular, these treatment steps aim to remove, at least partially, water, solid particles, fuel and / or other contaminants (organic and / or mineral), such as polycyclic aromatic hydrocarbons (PAHs), which are undesirable in the formulation of lubricants.

[0167] According to a particular embodiment, the regenerated lubricating oil implemented according to the invention comes from a used lubricant that has been subjected to one or more prior steps of dehydration, distillation, filtration, hydrogenation, liquid / liquid extraction, decantation and / or passing of the used lubricant over an adsorbent material, preferably as detailed below.

[0168] Preferably, the regenerated lubricating oil produced according to the invention is obtained by subjecting a used lubricating composition to at least one dehydration step. This dehydration step removes any water that may be present in the used lubricant.

[0169] Advantageously, the regenerated lubricating oil implemented according to the invention thus comprises a water content less than or equal to 10% by mass, in particular less than or equal to 5% by mass, in particular less than or equal to 2% by mass and more particularly less than or equal to 1% by mass, relative to the total mass of said regenerated lubricating oil.

[0170] This dehydration can be achieved by any method known to those skilled in the art, for example by distillation, evaporation, decantation, heating or passing a stream of hot air over the used lubricating composition.

[0171] According to one embodiment, the dehydration step can be carried out at a temperature between 50°C and 250°C, preferably between 100°C and 200°C. In particular, it can be carried out at a pressure between 50,000 and 150,000 Pa, preferably at atmospheric pressure.

[0172] Preferably, the regenerated lubricating oil produced according to the invention is obtained by subjecting a used lubricating composition to at least one preliminary filtration step. This filtration can be carried out by any method known to those skilled in the art. This filtration step may be a particulate or non-particulate filtration step. For example, it can be carried out using diatomaceous earth systems.

[0173] Preferably, the regenerated lubricating oil produced according to the invention is obtained by subjecting a used lubricating composition to at least one distillation step, preferably following a prior dehydration step. This distillation step(s) can be carried out using any technique known to those skilled in the art. For example, it could be atmospheric distillation or distillation under reduced pressure. The distillations can, for example, be carried out at a temperature between 100°C and 500°C, preferably between 200°C and 400°C, and more preferably between 300°C and 380°C. In particular, they can be carried out at a pressure between 25 Pa and 2,000 Pa, preferably between 50 Pa and 1,000 Pa, and more particularly between 50 Pa and 250 Pa.

[0174] Advantageously, the regenerated lubricating oil implemented according to the invention is obtained by subjecting a used lubricating composition to at least one prior step of passing said used lubricating composition over an adsorbent material.

[0175] The adsorbent material advantageously allows for the selective adsorption of aromatic compounds, particularly PAHs. In particular, passing over an adsorbent material, preferably activated carbon, advantageously reduces the content of polycyclic aromatic hydrocarbons (PAHs), notably selected from chrysene, benzo[b]fluoranthene, benzo[j]fluoranthene, benzo[k]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, dibenz[a,h]anthracene and / or benz[a]anthracene, of the used lubricant composition.

[0176] The term "passage of the used lubricating composition over an adsorbent material" refers to the flow of the used lubricating composition over the adsorbent support.

[0177] Absorbent materials can include, for example, activated carbon, zeolites, clays, or functionalized porous compounds. Preferably, activated carbon is used.

[0178] For example, the regenerated lubricating oil used in the process of the invention can be obtained from the treatment of a used lubricating composition according to the process described in document WO 2018 / 109208.

[0179] In the case of passing the used lubricating composition over activated carbon, the quantity of activated carbon used is preferably between 0.5 and 60 g of activated carbon per litre of used lubricating composition, preferably between 0.5 and 50 g / L, preferably from 1 to 50 g / L, preferably between 1 and 30 g / L, for example between 5 and 60 g / L, preferably between 5 and 50 g / L.

[0180] The flow rate of the used lubricant composition can be between 1 m 3 / h and 15 m3 / h, for example between 5 and 10 m 3 / h.

[0181] Preferably, activated carbon is characterized by a density between 200 and 500 kg / m³ 3 , for example measured according to the ASTDM D2854 standard.

[0182] Preferably, activated carbon is coal coal, preferably comprising 70% to 95%, advantageously 80% to 90% by weight of carbon.

[0183] The step of passing the used lubricating composition over an adsorbent support, preferably activated carbon, is advantageously preceded by the following preliminary steps:

[0184] - one or more distillation stages; and

[0185] - a filtration step, in particular as defined previously.

[0186] Advantageously, the regenerated lubricating oil produced according to the invention can be obtained by subjecting a used lubricating composition to at least one preliminary hydrogenation (or hydrotreating) step, preferably following a preliminary dehydration and / or distillation step. This hydrogenation step(s) can be carried out by any technique known to those skilled in the art and generally consist of treating the lubricating oil with hydrogen, usually in the presence of a hydrotreating catalyst. Such a catalyst may contain, for example, at least one oxide or sulfide of at least one Group VI metal and / or at least one Group VIII metal, such as molybdenum, tungsten, nickel, or cobalt, and a carrier, for example, alumina, silica-alumina, or a zeolite.

[0187] Advantageously, the regenerated lubricating oil produced according to the invention can be obtained by subjecting a used lubricating composition to at least one preliminary liquid / liquid extraction step with a solvent, preferably following a preliminary dehydration and / or distillation step. In particular, liquid / liquid extraction with a solvent advantageously clarifies dark-colored used oil and at least partially removes unpleasant odors or aromatic compounds, especially PAHs. This extraction step(s) can be carried out using any technique known to those skilled in the art. The extraction is generally performed in a mixer-settler or in an extraction column, using a suitable extraction solvent.

[0188] Advantageously, the regenerated lubricating oil implemented according to the invention can be obtained by subjecting a used lubricating composition to at least one preliminary settling step. This settling step(s) can be carried out using any technique known to those skilled in the art.

[0189] It is understood that the invention is in no way limited to the use of regenerated oils obtained according to the treatment methods described above. Other lubricating oils, at least partially re-refined, obtained from treatment steps other than those described above, may be suitable for the invention.

[0190] In any event, a re-refined lubricating oil implemented according to the invention differs from a used lubricating oil, in particular due to the reduced content of certain undesirable contaminants, for example water, fuel, metallic elements or certain heteroatoms.

[0191] On the other hand, a regenerated lubricating oil implemented according to the invention is distinguished, due to its formation from a used lubricant, from a virgin or new base oil, oil directly from petroleum refining, or even from native base oils, for example of natural origin, both in terms of its composition and its physico-chemical properties.

[0192] A regenerated lubricating oil implemented according to the invention is characterized in particular by a silicon content between 0 ppm and 300 ppm, in particular between 1 and 300 ppm.

[0193] A regenerated lubricating oil implemented according to the invention is characterized in particular by a phosphorus content less than or equal to 100 ppm, in particular between 0 ppm and 100 ppm, for example 0 ppm.

[0194] A regenerated lubricating oil implemented according to the invention can also be characterized by its content of one or more other elements selected from chlorine, oxygen, and nitrogen. For example, it may have a chlorine content between 0 ppm and 50 ppm, for example, 0 ppm.

[0195] The content of these elements can be evaluated by any method known to a person skilled in the art, for example by X-ray fluorescence (XRF), or by infrared or ultraviolet spectroscopy.

[0196] According to a particular embodiment, a regenerated lubricating oil implemented according to the invention has a density less than or equal to 870 kg / m³ 3 , in particular less than or equal to 860 kg / m 3 The density of the lubricating oil, at least partially re-refined, can thus be between 830 and 870 kg / m³. 3 , in particular between 840 and 860 kg / m 3 .

[0197] Density can in particular be determined according to the standard NF EN ISO 12185.

[0198] In particular, a regenerated lubricating oil implemented according to the invention has a flash point greater than or equal to 225°C, in particular greater than or equal to 228°C. The flash point of the lubricating oil, at least partially re-refined, can thus be between 225°C and 245°C.

[0199] The flash point can in particular be determined according to the NF EN ISO 2592 standard.

[0200] According to a preferred embodiment, the lubricating composition according to the invention comprises from 40% to 90% by mass, preferably from 45% to 80%, preferably from 50% to 70%, by mass of base oil(s) at least partly re-refined relative to the total mass of said lubricating composition.

[0201] A lubricating composition implemented according to the invention may further include all types of additives suitable for the intended use of the lubricant, as detailed in the following text, for example for use in mobile or stationary drive systems, more particularly mobile, for light or heavy vehicles, or even off-road vehicles, particularly in combustion drive systems.

[0202] These additives can be chosen from among friction modifiers, anti-wear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD) additives, dispersants, anti-foaming agents, thickeners, corrosion inhibitors, copper passivating agents, emulsifiers, and mixtures thereof.

[0203] Advantageously, a lubricating composition according to the invention comprises one or more additives selected from viscosity index improvers, pour point lowering additives, anti-wear additives, antioxidants and mixtures thereof.

[0204] These additives may be added to the regenerated base oil(s) used according to the invention, or to a mixture of the regenerated base oil(s) and at least one new base oil, in an appropriate quantity determined by those skilled in the art. It is understood that the nature and quantity of the additives used are chosen in such a way that the advantageous properties of the composition based on the re-refined lubricating oil(s) are not, or are not substantially, altered by the intended addition.

[0205] A lubricating composition implemented according to the invention may comprise between 0.01% and 20% by mass, in particular between 0.05% and 10% by mass of additives, in particular as described below, relative to the total weight of the composition.

[0206] Advantageously, a lubricating composition implemented according to the invention may include at least one friction-modifying additive. Friction-modifying additives reduce friction by forming adsorbed monolayers on the surfaces of the metals in contact. They may be selected from compounds containing metallic elements and from ash-free compounds. Examples of compounds containing metallic elements include transition metal complexes such as Mo, Sb, Sn, Fe, Cu, and Zn, whose ligands may be hydrocarbon compounds containing oxygen, nitrogen, sulfur, or phosphorus atoms.Ash-free friction-modifying additives are generally of organic origin and can be selected from fatty acid and polyol esters, other than the monoester required according to the invention, 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 10 to 24 carbon atoms. In particular, molybdenum-based compounds can be selected from molybdenum dithiocarbamates (Mo-DTC), molybdenum dithiophosphates (Mo-DTP), and mixtures thereof.

[0207] Advantageously, a lubricating composition 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 weight of the lubricating composition, of friction-modifying additives.

[0208] Preferably, a lubricating composition according to the invention comprises at least one anti-wear additive, one extreme-pressure additive, or mixtures thereof. Anti-wear and extreme-pressure additives are designed to protect friction surfaces by forming a protective film adsorbed onto them. A wide variety of anti-wear additives exist. Particularly suitable for lubricating compositions according to the invention are anti-wear additives selected from polysulfide additives, sulfur-containing olefin additives, or phospho-sulfur additives such as metallic alkylthiophosphates, especially zinc alkylthiophosphates, and more specifically zinc dialkyldithiophosphates or ZnDTP. Preferred compounds have the formula Zn((SP(S)(OR)(OR'))2, in which R and R', whether identical or different, independently represent an alkyl group, preferably comprising from 1 to 18 carbon atoms.

[0209] Advantageously, a lubricating composition according to the invention may comprise from 0.01% to 6% by mass, preferably from 0.05% to 4% by mass, and more preferably from 0.1% to 2% by mass, relative to the total weight of the composition, of anti-wear additives and extreme pressure additives. Advantageously, a lubricating composition according to the invention may comprise at least one antioxidant additive. The antioxidant additive delays the degradation of the lubricating composition in service. This degradation can manifest itself in particular through the formation of deposits, the presence of sludge, or an increase in the viscosity of the lubricating composition. Antioxidants act, in particular, as radical inhibitors or hydroperoxide scavengers.

[0210] Commonly used antioxidant additives include phenolic antioxidants, amine-type antioxidants, and phosphosulfur-containing antioxidants. Some of these antioxidants, such as phosphosulfur-containing antioxidants, can generate ash. Phenolic antioxidants may be ash-free or in the form of neutral or basic metal salts. Antioxidant additives may include sterically hindered phenols, sterically hindered phenol esters, sterically hindered phenols containing a thioether bridge, diphenylamines, diphenylamines substituted with at least one C1-C12 alkyl group, N,N'-dialkylaryl diamines, and mixtures thereof.

[0211] Preferably, sterically hindered phenols are chosen from compounds comprising a phenol group in which at least one vicinal carbon of the carbon bearing the alcohol functional group is substituted by at least one C1-C10 alkyl group, preferably a C1-C2 alkyl group, preferably a C4 alkyl group, and preferably by the tert-butyl group. Amino compounds are another class of antioxidant additives that can be used, possibly in combination with phenolic antioxidant additives. Examples of amine compounds are aromatic amines, for example, aromatic amines of formula NR 5 R 6 R 7 in which R 5 represents an aliphatic group or an aromatic group, possibly substituted, R 6 represents an aromatic group, possibly substituted, R 7represents a hydrogen atom, an alkyl group, an aryl group, or a group with the formula R 8 S(O) Z R 9 in which R 8 represents an alkylene group or an alkenylene group, R 9 represents an alkyl group, an alkenyl group or an aryl group and z represents 0, 1 or 2. Sulfurized alkyl phenols or their alkali and alkaline earth metal salts can also be used as antioxidant additives.

[0212] Advantageously, a lubricating composition according to the invention may comprise from 0.1% to 2% by mass, relative to the total weight of the composition, of at least one antioxidant additive. A lubricating composition according to the invention may also comprise at least one detergent additive. Detergent additives generally reduce the formation of deposits on the surface of metal parts by dissolving oxidation and combustion byproducts. Detergent additives usable in a lubricating composition according to the invention are generally known to those skilled in the art. Detergent additives may be anionic compounds comprising a long lipophilic hydrocarbon chain and a hydrophilic head group. The associated cation may be a metallic cation of an alkali or alkaline earth metal.Detergent additives are preferably chosen from alkali metal or alkaline earth metal salts of carboxylic acids, sulfonates, salicylates, naphthenates, and phenate salts. The alkali and alkaline earth metals are preferably calcium, magnesium, sodium, or barium. These metal salts generally contain the metal in stoichiometric amounts or in excess, i.e., in an amount greater than the stoichiometric amount. These are then called over-basic detergent additives; the excess metal that gives the detergent additive its over-basic character is then generally in the form of a metal salt insoluble in the base oil, for example, a carbonate, hydroxide, oxalate, acetate, or glutamate, preferably a carbonate.

[0213] A lubricating composition according to the invention may comprise from 0.5% to 8%, preferably from 0.5% to 4% by mass, relative to the total weight of the lubricating composition, of detergent additive.

[0214] Advantageously, a lubricating composition according to the invention may also include at least one pour point depressant (PPD) additive. By slowing the formation of paraffin crystals, pour point depressant additives generally improve the cold-weather performance of the lubricating composition according to the invention. Examples of pour point depressants include alkyl polymethacrylates, polyacrylates, polyarylamides, polyalkylphenols, polyalkylnaphthalenes, and alkylated polystyrenes.

[0215] A lubricating composition according to the invention may comprise from 0.1% to 2%, preferably from 0.2% to 1% by mass of pour point lowering additive(s), relative to the total weight of the composition. A lubricating composition according to the invention may also comprise at least one dispersing agent. Such dispersing agents ensure the suspension and removal of insoluble solid contaminants consisting of oxidation byproducts that form when the lubricating composition is in service. They may be selected from Mannich bases, succinimides and their derivatives, such as polyisobutylene succinic anhydride derivatives.

[0216] In particular, a lubricating composition according to the invention may comprise from 0.2% to 10% mass of dispersing agent(s), relative to the total weight of the composition.

[0217] A lubricating composition according to the invention may also include at least one viscosity index improver (VI). Viscosity index improvers, particularly viscosity index improving polymers, ensure good cold-weather performance and minimal viscosity at high temperatures. Examples of viscosity index improving polymers include polymer esters, hydrogenated or non-hydrogenated homopolymers or copolymers of styrene, butadiene, and isoprene, olefin homopolymers or copolymers such as ethylene or propylene, and polyacrylates and polymethacrylates (PMAs), preferably olefin homopolymers or copolymers such as ethylene or propylene.

[0218] In particular, a lubricating composition according to the invention may comprise from 1% to 15% by mass of additive(s) improving the viscosity index, preferably from 5% to 10% by mass, relative to the total weight of the lubricating composition.

[0219] A lubricating composition may also include at least one antifoaming additive, for example, selected from polar polymers such as polymethylsiloxanes or polyacrylates. In particular, a lubricating composition according to the invention may include from 0.01% to 3% by mass of antifoaming additive(s), relative to the total weight of the lubricating composition.

[0220] It may also include at least one anti-corrosion agent or copper passivating agent, for example compounds such as polyisobutenes succinic anhydrides, thiadiazole sulfonates, or mercaptobenzothiazoles. These are typically present in a lubricating composition according to the invention at concentrations between 0.01% and 1% by mass, relative to the total weight of the composition.Thus, a lubricating composition according to the invention may further comprise one or more base oils distinct from the lubricating oil, at least partly re-refined, and / or one or more additives, in particular selected from friction modifier additives, anti-wear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressant (PPD) additives, dispersants, anti-foaming agents, thickeners, corrosion inhibitors, copper passivating agents, emulsifiers, and mixtures thereof.

[0221] The present invention covers all motorized vehicles, preferably including at least one combustion engine, including heavy vehicles or light vehicles.

[0222] The present invention also relates to the use of a lubricating composition as defined above, for lubricating the parts of an internal combustion engine.

[0223] Preferably, the present invention also relates to the use of a lubricating composition as defined above, for lubricating the parts of internal combustion engines of the spark-ignition type, preferably gas, gasoline, diesel or hybrid engines, and more particularly for lubricating the parts of a diesel engine.

[0224] The present invention relates to the use of a lubricating composition as defined above for the lubrication of an engine.

[0225] The present invention also relates to a method of lubricating at least one mechanical part of the engine, said method comprising a step of bringing at least one mechanical part of said engine into contact with a lubricating composition as defined above.

[0226] The present invention also makes it possible to reduce the carbon footprint by using the aforementioned lubricating composition, and therefore by using at least one base oil that is at least partially re-refined, compared to using a lubricating composition comprising a virgin (or native) base oil. The present invention thus also relates to the use of the aforementioned lubricating composition to reduce the carbon footprint. The present invention relates to the use of a polyol triester obtained by reaction between a polyol and one or more acids, said polyol comprising at least three hydroxyl groups, in a lubricating composition comprising at least one base oil that is at least partially re-refined, to reduce the carbon footprint of said lubricating composition.

[0227] According to one embodiment, the polyol triester is as defined above and the base oil, at least partly re-refined, is as defined above.

[0228] The invention also relates to the use of at least one base oil, at least partially re-refined as defined above, as a base oil in a lubricating composition, to reduce the content of compound(s) of fossil origin.

[0229] Also, the present invention also relates to the use of a base oil at least partly re-refined as defined above in a lubricating composition in order to reduce the carbon footprint of said composition.

[0230] The invention also relates to the use of at least one base oil, at least partially re-refined as defined above, as a base oil in a lubricating composition comprising at least one polyol triester as defined above, to reduce the content of compound(s) of fossil origin.

[0231] Also, the present invention also relates to the use of a base oil at least partly re-refined as defined above in a lubricating composition comprising at least one polyol triester as defined above, in order to reduce the carbon footprint of said composition.

[0232] All the characteristics and preferences presented for the lubricating composition also apply to the processes / methods and uses according to the invention.

[0233] The invention will now be described by means of the following examples, given by way of illustration and not limitation of the invention. EXAMPLES

[0234] Example 1: Formulation of lubricating compositions according to the invention

[0235] Preparation of compositions

[0236] Lubricating compositions are prepared by mixing the compounds described in Table 3 below.

[0237] The percentages indicated correspond to percentages by mass relative to the total mass of the composition.

[0238] [Table 3]

[0239] (1) Package of additives including at least one detergent, one anti-wear agent and one dispersant.

[0240] (2) Polymethacrylate-type polymer improving viscosity index

[0241] (3) Regenerated base oil, having a viscosity measured at 100°C according to ASTM D445 (KV100) of 5.5 mm 2 / s,

[0242] (4) Group III base oil, having a viscosity measured at 100°C according to ASTM D445 (KV100) of 5.1 mm 2 / s,

[0243] (5) Trimethylolpropane triester (

[0244] (6) Neopentyl glycol triester. The characteristics of the lubricating compositions are shown in Table 4 below:

[0245] [Table 4]

[0246] KV100 (KV100 stands for Kinematic Viscosity measured at 100°C) corresponds to the kinematic viscosity measured at 100°C, measured according to the ASTM D445 standard.

[0247] CCS viscosity (from the English: "Cold Cranking Viscosity") is a measure of the dynamic viscosity of oil at low temperatures (-30°C). These values ​​are measured according to the ASTM D5293 standard.

[0248] HTHS viscosity (High Temperature, High Shear) is a measure of the viscosity of the residual oil film under high stress (mechanical shear pressure) at elevated temperatures. Here, the HTHS viscosity value of 150 is measured at 150°C according to CEC L-036-90 or ASTM D4683 standards.

[0249] Noack volatility at 250°C is measured according to the CEC L-40-A-93 method.

[0250] It is therefore observed that the composition of invention C1 meets the requirements of the 5W winter grade, unlike composition CC2 (which includes a polyol triester different from that according to the invention). It is also observed that the addition of a polyol triester according to the invention makes it possible to counteract the negative performance of a composition comprising a regenerated oil (but without a polyol triester) (corresponding to composition CC3). Example 2: Carbon footprint measurement

[0251] To determine the carbon footprint of the aforementioned compositions, LCA (life cycle analysis) calculations are carried out according to the methodology indicated below.

[0252] Measurement conditions: ISO 14040 and ISO 14044 standards.

[0253] Software used: SimaPro V.9.3.0.3.

[0254] Methodology for carbon footprint: based on the IPCC 2013 100-year global warming potential reference baseline (“GWP100”), adapted according to environmental footprint guidelines

[0255] The results are summarized in the following table 5.

[0256] [Table 5]

[0257] It is noted that the composition of the invention has an improved carbon footprint compared to the reference composition CC1 (22% reduction), but also compared to the comparative composition CC2 (with a diol triester instead of a triol triester).

Claims

36 DEMANDS 1. Lubricating composition of grade 5W according to SAE J300 classification, said lubricating composition comprising one or more base oils at least partly re-refined and at least one polyol triester obtained by reaction between a polyol and one or more acids, said polyol comprising at least 3 hydroxyl functions.

2. Lubricating composition according to claim 1, wherein the polyol is a triol or a tetraalcohol, preferably a triol.

3. Lubricating composition according to claim 1 or 2, wherein the polyol is a triol or a tetraalcohol, saturated or unsaturated, linear or branched, in C1 to C16.

4. Lubricating composition according to any one of the preceding claims, wherein the polyol triester is obtained by reaction between a polyol comprising at least 3 hydroxyl functions, and one or more carboxylic acids, in C2 to C30, preferably in C6 to C20.

5. Lubricating composition according to any one of the preceding claims, wherein the polyol triester is a triol triester formed between a triol, saturated or unsaturated, linear or branched, in C1 to C16, and one or more monocarboxylic acid(s), saturated, linear or branched, in C2 to C30, preferably in C6 to C20.

6. Lubricating composition according to any one of the preceding claims, wherein the polyol triester is a triol triester formed between trimethylolpropane and monocarboxylic acid(s), saturated, linear or branched, in C2 to C30, preferably C6 to C20.

7. Lubricating composition according to any one of the preceding claims, comprising from 5% to 50% by mass, preferably from 10% to 30%, preferably from 15% to 25%, by mass of polyol triester relative to the total mass of said lubricating composition. 37 8. Lubricating composition according to any one of the preceding claims, comprising from 40% to 90% by mass, preferably from 45% to 80%, preferably from 50% to 70%, by mass of base oil(s) at least partly re-refined relative to the total mass of said lubricating composition.

9. Lubricating composition according to any one of the preceding claims, wherein the base oil at least partly re-refined is derived or the base oils at least partly refined are derived from a used lubricant which has been subjected to one or more prior steps of dehydration, distillation, filtration, hydrogenation, liquid / liquid extraction, decantation and / or passing of the used lubricant over an adsorbent material.

10. Lubricating composition according to any one of the preceding claims, wherein the base oil or oils at least partially re-refined have a sulfur content of between 0.01% and 0.2% by mass, relative to the total mass of said oil or base oils at least partially re-refined, and / or wherein the base oil or oils at least partially re-refined have an aromatic compound content of more than or equal to 0.5% by mass, in particular more than or equal to 1% by mass, in particular between 1% and 25% by mass, more particularly between 2.5% and 20% by mass, relative to the total mass of said oil or base oils at least partially re-refined.

11. Lubricating composition according to any one of the preceding claims, wherein the base oil or oils, at least partly re-refined, have an alkylphenol content of 5 to 3,200 ppm, preferably 10 to 2,000 ppm, and preferably 15 to 1,500 ppm.

12. Lubricating composition according to any one of the preceding claims, wherein the lubricating composition further comprises one or more base oils distinct from the base oil or oils, at least partially re-refined, and / or one or more additives, in particular selected from friction modifiers, anti-wear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD) additives, dispersants, anti-foaming agents, thickeners, corrosion inhibitors, copper passivating agents, emulsifiers, and mixtures thereof.

13. Use of a lubricating composition according to any one of the preceding claims, for the lubrication of an engine.

14. Use of a lubricating composition according to any one of claims 1 to 11, to reduce the carbon footprint.

15. Use of a polyol triester obtained by reaction between a polyol and one or more acids, said polyol comprising at least 3 hydroxyl groups, in a lubricating composition comprising at least one base oil, at least partially re-refined, to reduce the carbon footprint of said lubricating composition, the polyol triester being in particular as defined in any one of claims 1 to 6 and the base oil, at least partially re-refined, being in particular as defined in any one of claims 1 and 7 to 10.

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