Use of at least partially re-refined lubricating oil for reducing wear

Abstract

The present invention relates to the use of at least one at least partially secondary refined lubricating oil for reducing wear of components in a mechanical system, in particular for reducing wear of moving components in a mechanical system.

Description

Technical Field

[0001] This invention relates to the field of lubricating compositions, and more particularly to the field of lubricating compositions for lubricating mechanical systems, especially moving parts in vehicles.

[0002] More specifically, this invention relates to the use of secondary refined lubricating oil for reducing wear on components in mechanical systems, specifically for reducing wear on moving parts in mechanical systems, and particularly for reducing mechanical fatigue pitting on moving parts in mechanical systems. Background Technology

[0003] A typical cause of damage to mechanical systems is fatigue damage resulting from repeated stress. This phenomenon is caused by repeated rolling stress under heavy loads. It primarily manifests as pitting (surface fatigue).

[0004] Contact stress is reduced by using appropriate component geometry, and this phenomenon is prevented by reducing friction while avoiding adhesion.

[0005] Therefore, lubricating compositions known as "lubricants" are typically used in various components of motor vehicles. Their primary purpose is to reduce friction between the moving metal parts in these components (specifically, the engine, transmission system, and hydraulic circuits), thereby protecting them from wear. They are thus used to prevent premature wear or even damage to these components, particularly surface wear.

[0006] Therefore, lubricating compositions typically consist of one or more base oils, often with the addition of various additives specifically designed to enhance the lubricating properties of the base oils, such as friction-improving additives.

[0007] Therefore, lubricants play a role in prevention through their viscosity and the physicochemical reactivity of their additives. Thus, a type of performance particularly useful for lubrication compositions in mechanical systems is the presence of excellent wear-resistant properties, all of which fall within the requirements that must be met in the manufacturer's technical specifications.

[0008] To this end, various solutions have been proposed, such as surface treatment, adding sulfur- and / or phosphorus-containing additives to the composition, or using nanoparticles.

[0009] However, these solutions are not satisfactory in some respects.

[0010] In practice, sulfur-containing additives, as well as phosphorus-containing and phosphorus-sulfur-containing additives, are widely used in oil formulations as anti-wear and extreme pressure additives. They provide protection to components by forming an adsorbed film on the surface of frictional parts subjected to high loads. Sulfur-containing additives, in particular, prevent seizing, a phenomenon that occurs from the outset when the interfacial resistance exceeds that of the substrate.

[0011] However, despite the existence of numerous anti-wear additives, extreme pressure additives, or friction-modifying additives, their effects are not the same, and some may improve one property while impairing another.

[0012] Moreover, these additives have complex chemical properties, and they may react with each other to form new chemical substances. Their effects on extreme pressure, wear, friction, and jamming characteristics are ultimately unclear.

[0013] Furthermore, the proposed surface treatment methods are costly, and nanoparticles suffer from suspension stability issues, particularly causing filter clogging in mechanical equipment. Moreover, these solutions are unsatisfactory from an environmental perspective.

[0014] Therefore, in order to meet the growing expectations of avoiding the use of toxic solvents and reducing the environmental impact of products, research has also been conducted on the development of water-based lubricants.

[0015] For example, patent application WO 2021 / 259853 describes an aqueous lubricating composition comprising a polyether polyol, an antifreeze compound, and a phosphorus-containing compound.

[0016] However, this water-based lubricant is not entirely satisfactory in preventing the mechanical fatigue pitting phenomenon that may occur. In fact, it has been found that this lubricating composition can produce such defects in mechanical contact, particularly related to the formulation method of the composition.

[0017] Therefore, it is necessary to extend the service life of friction-affected components in mechanical systems by limiting the occurrence of wear phenomena, especially limiting mechanical fatigue pitting.

[0018] At the same time, there is a demand for more environmentally friendly lubricating compositions, which exhibit excellent properties in reducing wear, especially in reducing mechanical fatigue pitting. Summary of the Invention

[0019] The present invention aims to propose the use of specific oils to meet these expectations.

[0020] Specifically, the inventors have discovered that recycled base lubricants are particularly suitable for use in lubrication compositions to reduce wear on components in mechanical systems, specifically reducing wear on moving parts in mechanical systems.

[0021] The present invention aims to propose a new use for at least partially secondary refined lubricating oil to reduce or even avoid wear phenomena, specifically to reduce or even avoid mechanical fatigue pitting.

[0022] Therefore, according to a first aspect, the present invention relates to the use of a composition based on a lubricating oil that is at least partially refined for reducing wear on components in a mechanical system, specifically for reducing wear on moving parts in a mechanical system.

[0023] Surprisingly, as illustrated in the examples below, the inventors have discovered that secondary refined oil from waste oil recycling systems allows for the production of lubricants with improved properties in reducing wear on components in mechanical systems, particularly reducing mechanical fatigue pitting on moving parts in mechanical systems.

[0024] Within the scope of this invention, the expression "at least partially secondary refined lubricating oil," which may also be referred to as "secondary refined oil," "recycled oil," or "recovered oil" hereinafter, refers to an oil obtained from a waste lubricating composition through one or more known secondary refining processes.

[0025] In this invention, "waste lubricating composition" (or simply "waste lubricant" or "waste lubricating oil") refers to any lubricating composition used for lubricating moving parts in a mechanical system, specifically metal parts, such as, but not limited to, bearings, gears, or motors.

[0026] In this invention, "moving component" refers to any combination of at least two components that have relative motion. Specifically, it can be a component in a bearing system, especially inside a motor, in a transmission system, or in a hydraulic circuit, particularly a metal component.

[0027] Waste lubricating oil can come from various sources. In particular, as described below, it can be a lubricant used to lubricate power systems (specifically "moving systems") or so-called industrial systems (specifically "stationary systems").

[0028] Due to its origin, waste lubricating oil, specifically motor lubricating oil, includes degradation products from the oil itself or its additives, as well as metal particles, metal oxides, and other elements from the engine. Specifically, waste oil may contain high levels of useless elements such as calcium (Ca), iron (Fe), magnesium (Mg), sodium (Na), nickel (Ni), phosphorus (P), silicon (Si), chlorine (Cl), and zinc (Zn).

[0029] Methods for secondary refining or reprocessing of waste lubricating oils have been developed to regenerate these oils and allow for their subsequent reuse.

[0030] Therefore, secondary refined lubricating oil is an oil obtained from waste lubricant through one or more processing steps. These processing steps aim to remove at least partially certain contaminants present therein, including dust, water, hydrocarbons, metallic elements, and other degradation residues of additives present in the lubricant.

[0031] Preferably, as described below, the lubricating oils used in this invention, at least partially refined, have characteristics that meet the standards set by the API classification for Group I or Group II oils, particularly in terms of saturated compound content, sulfur content, and viscosity index.

[0032] The lubricating oil used in this invention, preferably a partially secondary refined lubricating oil, has a dynamic viscosity greater than or equal to 4.0 mm² measured at 100°C according to ASTM D445 standard. 2 / s, especially in the 4.0-12 mm range 2 The variation is between / s, specifically greater than or equal to 4.3 mm. 2 / s, more specifically in the range of 4.4-10 mm 2 Variations between / s, especially between 5.0 and 6.5 mm 2 / s.

[0033] To the inventor's knowledge, the use of recycled lubricating oil has never been proposed to reduce wear on components in a mechanical system, or more specifically, to reduce mechanical fatigue pitting on moving parts in a mechanical system.

[0034] "Mechanical fatigue pitting" refers to the deterioration of a surface, especially the surface of moving parts in a mechanical system, caused by fatigue. This deterioration is caused by the shedding of fragments of different sizes from the component due to the propagation of fatigue cracks.

[0035] Fatigue cracks occur when cyclic stress accumulates beyond the fatigue limit of a component. Surface mechanical fatigue pitting specifically affects the metal surfaces of components, especially those subjected to high-load Hertzian contact under elastohydrodynamic conditions of pure rolling or rolling-sliding.

[0036] This invention uses secondary refined lubricating oil to reduce wear on components in mechanical systems, demonstrating advantages in several aspects.

[0037] On the one hand, as shown in the embodiments below, the inventors have demonstrated that secondary refined lubricants can prevent mechanical fatigue pitting of moving parts, specifically moving parts in power systems, with an effect at least equivalent to that of lubricating compositions using only virgin base oils.

[0038] In fact, surprisingly, the inventors discovered that, compared to lubricating compositions containing only virgin base oils from the same source, secondary refined lubricants allow for improved resistance to mechanical fatigue pitting in moving parts, specifically in power systems. To the inventors' knowledge, such results had never been achieved before.

[0039] Refined base oils, also known as "virgin" or "new" base oils, are different from secondary refined lubricants. They are oils that are directly refined from petroleum and have not been used before.

[0040] On the other hand, the use of recycled lubricants advantageously meets current expectations for reducing environmental impact and conserving resources. Therefore, compared to using virgin base oils, using recycled lubricants advantageously allows for a reduction in the carbon footprint of the product.

[0041] In one specific embodiment, the present invention relates to the use of at least one at least partially secondary refined lubricating oil to reduce mechanical fatigue pitting of moving parts in a mechanical system.

[0042] As detailed below, the moving parts may constitute the whole or part of the power system, specifically a moving or stationary fuel, electric or hybrid power system, specifically the power system in a vehicle (specifically a light vehicle, heavy vehicle or water vehicle).

[0043] According to another aspect, the present invention also relates to the use of at least one lubricating composition comprising at least one partially secondary refined lubricating oil for reducing wear of components in a mechanical system, specifically for reducing wear of moving parts in a mechanical system, and more specifically for reducing mechanical fatigue pitting of moving parts in a mechanical system.

[0044] Preferably, the at least one secondary refined lubricating oil accounts for more than 50% by mass of the total mass of the composition containing at least one of the oils, specifically more than 70% by mass, especially more than 75% by mass, and more specifically more than 80% by mass.

[0045] As detailed below, the at least one secondary refined lubricating oil can be used as the sole base oil; in other words, no other base oil, such as virgin base oil, needs to be added. Alternatively, they can be mixed with at least one virgin base oil.

[0046] The at least one secondary refined lubricating oil can be mixed with one or more other components. Specifically, one or more additives can be added, such as, but not limited to, corrosion inhibitors, antioxidants, etc.

[0047] The present invention also relates to a method for reducing wear of components in a mechanical system, specifically for reducing wear of moving parts in a mechanical system, the method comprising at least the step of circulating a composition based on at least one at least partially secondary refined lubricating oil in the mechanical system.

[0048] The present invention also relates to a method or process for preparing a lubricating composition, comprising at least the step of obtaining at least a portion of a secondary refined lubricating oil from waste lubricant.

[0049] The preparation method of this composition may specifically include the following steps:

[0050] (i) Using waste lubricant to prepare at least partially secondary refined lubricating oil;

[0051] (ii) Optionally, the at least partially secondary refined lubricating oil is mixed with one or more new base oils different from the secondary refined lubricating oil, such as one or more mineral oils;

[0052] (iii) Optionally, at least one additive may be added to the lubricating oil that has been at least partially refined in step (i) or the lubricating oil mixture in step (ii), specifically selected from corrosion inhibitors, friction modifiers, extreme pressure additives, anti-wear additives, detergents, antioxidants, viscosity index (VI) improvers, pour point (PPD) reducers, dispersants, defoamers, and mixtures thereof.

[0053] Advantageously, the use of the secondary refined lubricant of the present invention thus allows for meeting current expectations of reducing environmental impact and conserving resources through two avenues: one is that, compared to using virgin base oils, the lubricant formulation based on recycled lubricant allows for a reduction in the carbon footprint of the product; the other is that, as mentioned above, the use of secondary refined base oils allows for an effective reduction in wear on components in mechanical systems, specifically reducing wear on moving parts in mechanical systems, and more specifically reducing mechanical fatigue pitting on moving parts in mechanical systems.

[0054] Other features, variations, and advantages of using lubricating oils and related compositions that are at least partially secondary refined will be better illustrated by reading the following description and examples, which are exemplary and not limiting of the invention.

[0055] Unless otherwise stated, expressions such as “between… and…”, “from… to…”, “from… to…”, and “change between… and…” should be understood to include their boundary values.

[0056] In the description and examples, all percentages given are by mass percentages unless otherwise stated. Therefore, percentages are expressed as a percentage by mass of the total mass of the composition. Attached Figure Description

[0057] Figure 1 A two-dimensional chromatogram of the first secondary refined lubricating oil of the present invention is shown, namely oil J in the experimental part;

[0058] Figure 2 A two-dimensional chromatogram of the second type of secondary refined lubricating oil of the present invention is shown, namely, oil H in the experimental part. Detailed Implementation

[0059] At least partially secondary refined lubricating oil

[0060] As described above, the oil used in this invention is a lubricating oil that has been at least partially refined twice, also known as "recycled oil" or "reclaimed oil". In other words, the present invention can use a lubricating oil obtained from waste lubricating compositions through one or more secondary refining processes.

[0061] It should be noted that the waste lubricant composition can be a mixture of multiple waste lubricant compositions from the same source or multiple different sources.

[0062] The waste lubricant composition and associated recycled lubricant primarily comprise one or more base oils commonly used in the lubricant field, such as mineral oil, synthetic oil or natural oil, animal oil or vegetable oil, or mixtures thereof.

[0063] This can be a mixture of multiple base oils, such as a mixture of two, three, or four base oils.

[0064] These base oils can be of natural origin, such as from plants or animals, including vegetable oils, animal oils, fish oils, and mixtures thereof. Examples of such oils include rapeseed oil, canola oil, tall oil, sunflower oil, soybean oil, hemp oil, olive oil, flaxseed oil, mustard oil, palm oil, peanut oil, castor oil, coconut oil, animal fats, and mixtures thereof.

[0065] Specifically, these base oils are mineral oils or synthetic oils, belonging to categories I to V as defined in the API classification (or the equivalent ATIEL classification), as shown in the table below, or mixtures thereof.

[0066] [Table 1]

[0067]

[0068] Specifically, the waste lubricating composition from which the recycled lubricating oil used in this invention is obtained may contain base oil accounting for 50% of its total weight, specifically at least 60% by weight, and more specifically 60%-99% by weight.

[0069] The secondary refined lubricating oil used in this invention has certain characteristics in terms of saturated compound content, sulfur content and viscosity index, which meet the standards set by API for Group I, II, III, IV and / or V oils, specifically Group I, II, III and / or IV oils.

[0070] Therefore, the present invention is intended for use of a composition wholly or partially formed of at least one secondary refined lubricating oil, said lubricating oil being obtained from waste lubricant through one or more processing steps, said waste lubricant being an oil based on one or more API classifications of Groups I to V.

[0071] According to one specific embodiment, the secondary refined lubricating oil used in this invention can be obtained by treating waste lubricating compositions used for lubricating power systems, specifically "sporting" systems, including light vehicles, heavy vehicles, so-called "off-road" sports machinery, or water vehicles.

[0072] According to another specific embodiment, the secondary refined lubricating oil used in this invention can be obtained by treating waste lubricating compositions used in lubrication industrial systems, specifically "stationary" systems, including but not limited to turbines, compressors, hydraulic systems, gears, or forming or cutting machines.

[0073] The waste lubricating composition from which the recycled lubricating oil used in this invention is obtained 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, defoamers, thickeners, and mixtures thereof.

[0074] As mentioned above, the properties of waste lubricating compositions degrade after a period of use, whether long or short, during the lubrication and / or cooling process of mechanical systems (specifically power systems such as internal combustion engines).

[0075] Therefore, depending on its source, the waste lubricant composition may contain one or more of the above-mentioned additives, as well as impurities generated from the degradation of additives originally present in the lubricant, or impurities generated from the wear of moving mechanical parts.

[0076] Waste lubricant compositions will obviously vary depending on the source of the lubricant, its initial formulation, and the different contaminations it may be subject to due to its intended use.

[0077] The recycled lubricating oil used in this invention is more specifically obtained from waste lubricating compositions through one or more pretreatment steps, which are well known in the field of secondary refining of waste lubricants.

[0078] Specifically, these treatment steps are designed to remove at least partially moisture, solid particles, hydrocarbons and / or other contaminants, such as polycyclic aromatic hydrocarbons (PAHs), which are useless in lubricant formulations.

[0079] According to a specific embodiment, the recycled lubricating oil used in this invention is obtained from waste lubricant after undergoing one or more pretreatment steps, including dehydration, distillation, filtration, hydrogenation, liquid-liquid extraction, sedimentation, and / or passing the waste lubricating oil through an adsorbent material, preferably as detailed below.

[0080] Therefore, the present invention relates to the use of at least one partially secondary refined lubricating oil, specifically formed from at least one partially secondary refined lubricating oil, preferably as described above, wherein the at least partially secondary refined lubricating oil is obtained from a waste lubricating composition through one or more steps, including dehydration, distillation, filtration, hydrogenation, liquid-liquid extraction, sedimentation and / or passing the waste lubricating composition through an adsorbent material, preferably operated under conditions detailed below.

[0081] Preferably, the recycled lubricating oil used in this invention is obtained by subjecting the waste lubricating composition to at least one dehydration step. This dehydration step allows the removal of any moisture that may be present in the waste lubricant.

[0082] Preferably, the water content of the recycled lubricating oil used in this invention is less than or equal to 10% of the total mass of the recycled lubricating oil, specifically less than or equal to 5%, especially less than or equal to 2%, and more specifically less than or equal to 1%.

[0083] The dehydration can be accomplished by any method known to those skilled in the art, such as by distillation, evaporation, sedimentation, heating, or passing a hot gas stream through the waste lubricating composition.

[0084] According to one embodiment, the dehydration step can be operated at a temperature of 50°C-250°C, preferably 100°C-200°C. Specifically, it can be operated at a pressure of 50,000-150,000 Pa, preferably at atmospheric pressure.

[0085] Preferably, the recycled lubricating oil used in this invention is obtained by subjecting the waste lubricating composition to at least one pretreatment filtration step. This filtration can be carried out by any method known to those skilled in the art. The filtration step can be a particulate or non-particulate filtration step. For example, it can be carried out using a diatomaceous earth-based system.

[0086] Preferably, the regenerated lubricating oil used in this invention is obtained by subjecting the waste lubricating composition to at least one distillation step. Preferably, this distillation step is performed after a pretreatment dehydration step. The at least one distillation step can be carried out using any technique known to those skilled in the art. For example, it can be atmospheric distillation or vacuum distillation. The operating temperature of the distillation can vary, for example, between 100°C and 500°C, preferably between 200°C and 400°C, more preferably between 300°C and 380°C. Specifically, the operating pressure of the distillation can vary between 25 and 2000 Pa, preferably between 50 and 1000 Pa, more specifically between 50 and 250 Pa.

[0087] Preferably, the recycled lubricating oil used in this invention is obtained by subjecting the waste lubricating composition to at least one pretreatment step involving passing the waste lubricating composition through an adsorbent material.

[0088] The adsorbent material advantageously allows for the selective adsorption of aromatic compounds, specifically PAH.

[0089] Specifically, by means of an adsorbent material, preferably activated carbon, the content of polycyclic aromatic hydrocarbons (PAHs) in the waste lubricating composition can be advantageously reduced, especially those selected from α, benzo[b]fluoranthene, benzo[j]fluoranthene, benzo[k]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, diphenyl[a,h]anthene and / or benzene[a]anthene.

[0090] "Waste lubricating composition passing through adsorption material" refers to the waste lubricating composition flowing on an adsorption carrier.

[0091] The adsorbent material can be, for example, activated carbon, zeolite, clay, or functionalized porous compounds. Activated carbon is preferred.

[0092] For example, the recycled lubricating oil used in this invention can be obtained by treating waste lubricating compositions according to the method described in document WO 2018 / 109208.

[0093] When the waste lubricating composition is passed through activated carbon, the amount of activated carbon used is preferably 0.5-60 g of activated carbon per liter of waste lubricating composition, preferably 0.5-50 g / L, preferably 1-50 g / L, preferably 1-30 g / L, for example 5-60 g / L, preferably 5-50 g / L.

[0094] The flow rate of the waste lubricating composition can be 1 m³. 3 / h-15 m 3 The value varies between / h, for example, 5-10 m 3 / h.

[0095] Preferably, the activated carbon is characterized by a density variation range of 200-500 kg / m³, as measured according to, for example, the ASTDM D2854 standard.3 .

[0096] Preferably, the activated carbon is coal-based activated carbon, preferably containing 70%-95% carbon by weight, and more preferably 80%-90% carbon by weight.

[0097] After the waste lubricating composition passes through the adsorption carrier step, and preferably through the activated carbon step, the following pretreatment step is advantageously performed:

[0098] - One or more distillation steps; and

[0099] - The filtering steps are as described above.

[0100] Preferably, the regenerated lubricating oil used in this invention can be obtained by subjecting the waste lubricating composition to at least one pretreatment dehydration (or hydrogenation) step, preferably after the pretreatment dehydration and / or distillation steps. The one or more hydrogenation steps can be carried out by any technique known to those skilled in the art, and typically involve treating the lubricating oil with hydrogen, often in the presence of a hydrogenation catalyst. Such catalysts may, for example, contain at least one Group VI metal oxide or sulfide and / or at least one Group VIII metal oxide or sulfide, such as molybdenum, tungsten, nickel, or cobalt, and a support, such as alumina, aluminosilicate, or zeolite.

[0101] Preferably, the recycled lubricating oil used in this invention can be obtained by subjecting the waste lubricating composition to at least one pretreatment solvent liquid-liquid extraction step, preferably after a pretreatment dehydration and / or distillation step. Specifically, solvent liquid-liquid extraction advantageously allows the clarification of dark waste oil, at least partially removing odorous or aromatic compounds, especially PAHs. The at least one extraction step can be carried out using any technique known to those skilled in the art. This extraction is typically carried out using a suitable extraction solvent in a mixing-settling tank or extraction column.

[0102] Preferably, the recycled lubricating oil used in this invention can be obtained by subjecting the waste lubricating composition to at least one pretreatment settling step. The at least one settling step can be carried out using any technique known to those skilled in the art.

[0103] It should be noted that this invention is not limited to the recycled oil obtained by the above-described processing method. Other lubricating oils that have undergone at least partial secondary refining, such as Group I / II lubricating oils, with different processing steps than those described above, may also be applicable to this invention.

[0104] In any case, the secondary refined lubricating oil used in this invention differs from waste lubricating oil, especially because it has a lower content of certain useless contaminants, such as water, hydrocarbons, metal elements, or certain heteroatoms.

[0105] The main characteristic of the regenerated lubricating oil used in this invention is that its silicon content varies between 0 ppm and 300 ppm, especially between 1 and 300 ppm.

[0106] The main characteristic of the regenerated lubricating oil used in this invention is that its phosphorus content is less than or equal to 100 ppm, specifically varying between 0 ppm and 100 ppm, for example, 0 ppm.

[0107] The regenerated lubricating oil used in this invention is further characterized by containing one or more other elements selected from chlorine, oxygen, and nitrogen. For example, its chlorine content can vary between 0 ppm and 50 ppm, for example, 0 ppm.

[0108] The content of these elements can be estimated by any method known to those skilled in the art, such as X-ray fluorescence spectroscopy (XRF), infrared spectroscopy, or ultraviolet spectroscopy.

[0109] According to one embodiment, the secondary refined lubricating oil of the present invention contains one or more alkylphenols. "Alkylphenol" refers to a phenolic compound with an alkyl group R1 at the para-position, and therefore has the chemical formula R1-C6H4-OH. The presence of alkylphenols is characteristic of secondary refined lubricating oils because virgin oils (unused oils) do not contain alkylphenols.

[0110] Preferably, the alkylphenol content in the secondary refined lubricating oil of the present invention is 5-3200 ppm, specifically 10-2000 ppm, and more preferably 15-1500 ppm.

[0111] According to one embodiment, the secondary refined lubricating oil of the present invention contains 10-300 ppm alkylphenol, preferably 15-250 ppm alkylphenol.

[0112] According to another embodiment, the secondary refined lubricating oil of the present invention contains 150-2000 ppm alkylphenol, preferably 200-1500 ppm alkylphenol.

[0113] The alkylphenol content of the secondary refined lubricating oil was measured according to the method described in patent application FR 23 15133.

[0114] This method is based on liquid chromatography and mass spectrometry steps and uses the standard compound 4-hexadecylphenol.

[0115] In the liquid chromatography procedure, a column packed with C8-bonded silica particles was used. Measurements were performed at 40°C at a flow rate of 0.4 mL / min.

[0116] A so-called reversed-phase column is used here to separate the various components of the sample (in this case, the secondary refined lubricating oil to be analyzed) according to the polarity of the sample. The composition of the mobile phase is adjusted so that these interactions change over time, and thus the various molecules in the sample being analyzed (in this case, the secondary refined lubricating oil) are gradually eluted.

[0117] The mobile phase is used in a gradient manner, as shown in the table below, consisting of solution A containing 50% water and 50% acetonitrile and solution B containing 100% methanol.

[0118]

[0119] Mass spectrometry can be used to obtain the signals produced by target molecules, and these molecules can be identified by their mass and retention time.

[0120] The preferred ionization source used is an electrospray ionization (ESI) source, which allows for the selective ionization of polar compounds. If this method is used here, the selected detection mode is a negative ion detection mode, as it allows for the selective ionization of polar compounds with acidic characteristics. The mass-to-charge ratio (m / z) ranges from 100 to 1200.

[0121] Specifically, the method for measuring the alkylphenol content in the secondary refined lubricating oil used in this invention includes a first step of preparing a standard solution (4-hexadecylphenol) and a solution to be analyzed (secondary refined lubricating oil).

[0122] - Prepare standard solutions of different concentrations by diluting with THF and adding 2% ammonium hydroxide to obtain calibration curves, which will be explained further below;

[0123] - The secondary refined lubricating oil solution was prepared by diluting it in THF and adding 3% ammonium hydroxide.

[0124] To establish a calibration curve, the peak intensity of the 4-hexadecylphenol ion in the standard was obtained by plotting extracted ion chromatograms (EIC). This allows for obtaining chromatograms extracted at a given m / z ratio, i.e., at m / z 317.28 for this standard molecule, with the deprotonated form corresponding to C1. 22 H 37 O − Ions. Therefore, the EIC intensity was recorded for each analysis at various test concentrations.

[0125] The obtained data allowed for the construction of a calibration curve. This calibration curve was obtained by injecting standard solutions of various concentrations: the curve was constructed using linear regression, and the linearity of the detector and the correctness of the standard solutions were verified by calculating the correlation coefficient (R²).

[0126] The correlation equation allows the prediction of the concentration of an unknown sample by inputting the y-value obtained from the experiment. Here, the equation is as follows:

[0127]

[0128] To quantify alkylphenols in the secondary refined lubricating oil of this invention, the analytical method includes the following steps: identifying the m / z ratio of alkylphenol residues on an average mass spectrum by integrating the entire chromatogram. This average mass spectrum corresponds to the average of all mass spectra obtained throughout the chromatographic run. This allows for the acquisition of all compounds ionized during the analysis. A list of mass spectra summarizing all m / z ratios of the ions and their associated intensities is extracted from this average mass spectrum.

[0129] The next step is to use this mass spectrum list to construct a Kendrick diagram. This is a molecular map that allows the identification of a series of compounds of the same type but different degrees of alkylation by eliminating mass deviations in the CH2 unit.

[0130] Kendrick diagrams can be created by calculating the following values:

[0131]

[0132] Where KM corresponds to the Kendrick mass, and IUPAC mass corresponds to the theoretical mass, which is calculated based on the sum of the elements that make up the target molecule. In this case, the target molecule has the chemical formula C. 22 H 37 O - The standard molecular weight of hexadecylphenol, IUPAC mass = 317.284440 g·mol⁻¹ -1 EXPER mass corresponds to the experimental mass measurement value, that is, the mass measured in the experiment.

[0133] The Kendrick KM mass is calculated for each peak of the average mass spectrum as determined above.

[0134] Then, Kendrick MKD quality defects are typically calculated using the following equation:

[0135]

[0136] KMD corresponds to Kendrick quality defects.

[0137] KM corresponds to Kendrick mass.

[0138] NKM is Kendrick KM mass rounded to the nearest integer.

[0139] Kendrick KMD quality defects are calculated for each peak (e.g., each peak corresponds to a compound present in the secondary refined lubricant).

[0140] The Kendrick diagram corresponds to a two-dimensional molecular diagram, showing the KMD as a function of NKM. Homologous compounds with different degrees of alkylation appear as horizontal lines.

[0141] By applying a filter to the vertical axis (KMD), all m / z ratios of alkylphenols can be obtained: i.e., KMD value = 0.069. Once all m / z ratios with KMD = 0.069 are identified, they are used to construct extracted ion chromatograms (EICs), as described for standard molecules. This allows for obtaining chromatograms that relate only to the desired m / z ratio. Therefore, the EIC intensities for each m / z ratio corresponding to the alkylphenol are summed to obtain the total intensity (from the spectrum of secondary refined lubricating oils according to the present invention, various types of alkylphenol molecules can be obtained, differing only in the length of their alkyl chains).

[0142] To perform quantification, the sum of the obtained EIC intensities is used as the y-value in the equation of the correction curve. For example, if the obtained value is 2.45... E 6. The quantitative amount of alkylphenol residue in the secondary refined lubricating oil used in this invention is:

[0143]

[0144]

[0145] Therefore, x equals 2460.6 ppm.

[0146] According to one embodiment, the secondary refined lubricating oil of the present invention contains one or more polyolefin alkanes (PAOs). The presence of polyolefin alkanes is a characteristic of secondary refined lubricating oils because virgin oil (unused oil) does not contain polyolefin alkanes (PAOs).

[0147] Figure 1 and Figure 2 Two-dimensional chromatograms of two secondary refined lubricating oils of the present invention are shown. The arrows on each chromatogram indicate PAO (C... 30 The characteristic peaks of this are markers for secondary refined oil.

[0148] According to one embodiment, the secondary refined lubricating oil of the present invention comprises one or more polyolefin alkanes (PAOs) containing less than 40 carbon atoms, preferably 30 carbon atoms.

[0149] The presence of PAO in the secondary refined lubricating oil was determined according to the method described in patent application No. FR 2406231.

[0150] This method is based on the steps of performing two-dimensional integrated gas chromatography (GCxGC) and classification.

[0151] Specifically, it is implemented by a chromatographic apparatus comprising a two-dimensional integrated gas chromatography module, including a first chromatographic column A and a second chromatographic column B, capable of separating various compounds in the product based on volatility and polarity. The apparatus also includes a flame ionization detector capable of measuring the ionization current intensity generated by each compound contained in the product. The apparatus is calibrated using at least one calibrator, allowing correction of the retention times of various compounds present in the product.

[0152] The method is also implemented using an electronic sorting device, including the following steps:

[0153] a. Based on the measurements of the product performed by the chromatographic apparatus, determine a table that describes the ionization current intensity produced by each compound contained in the product in chromatographic columns A and B as a function of the corrected retention time.

[0154] b. The algorithm was trained by applying a multivariate statistical algorithm to the table, assigning one of the multiple categories to the product, based on the table obtained from the reference product.

[0155] The chromatographic apparatus includes a two-dimensional integrated gas chromatography module, comprising a first column A and a second column B. The two-dimensional integrated gas chromatography (2DGC or GCxGC) modules that can be used in this disclosure are those described in the literature.

[0156] These modules typically include an injection module, a vaporization module, a first column A, a modulator, and a second column B. They allow for two-dimensional separation of complex mixtures because the product undergoes two separations, resulting in a two-dimensional chromatogram showing the retention times of each column (A) and column (B), as well as a table describing the changes in the intensity of the ionization current generated by each compound in the product with the corrected retention times of each column (A) and column (B).

[0157] According to one embodiment, the first chromatographic column A and the second chromatographic column B are partially phenyl-functionalized polydimethylsiloxane columns. The percentage of phenyl functionalization can be between 2% and 50%. According to a specific embodiment, the percentage of phenyl functionalization in chromatographic column A is higher than that in chromatographic column B. Advantageously, the length of chromatographic column A is greater than the length of column B. The diameters of the two chromatographic columns A and B can be equal. The membrane thickness of the two chromatographic columns can be 0.1 µm, suitable for separating low-volatility samples. According to one embodiment, the temperature gradient applied to the oven is 2 °C / min until it reaches 400 °C.

[0158] A certain amount of the product is injected into the first chromatographic column A to achieve the first separation, and then injected into the second chromatographic column B through a modulator to achieve the second separation. The product can be injected directly without pretreatment, especially when analyzing lubricating oils.

[0159] The GCxGC apparatus is connected to a flame ionization detector (FID). It measures the ionization current intensity produced by each compound contained in the product. The flame ionization detector is located at the outlet of the second column.

[0160] Following flame ionization detector (FID) analysis, a table was generated depicting the ionization current intensity as a function of calibrated retention time for each compound contained in the product, produced in columns A and B. Therefore, this table was obtained from a two-dimensional chromatogram, which was obtained by measuring the product using a chromatographic apparatus.

[0161] Additionally, in this initial step, external calibration is performed to allow for the correction of retention times of various compounds present in the product. This is accomplished by injecting at least one calibrator. If the product to be classified is a lubricant, the calibrator can also be a lubricant, preferably a recycled lubricant. According to one embodiment, the calibrator contains at least one marker, preferably at least two markers. The markers can be selected from n-alkanes, polyolefins, and mixtures thereof. Retention time correction can be performed using software.

[0162] After this initial step is completed, the sorting device proceeds to the next step, in which it assigns the corresponding category from multiple categories to the products through its product allocation module. This is done by applying a multivariate statistical algorithm to a table, which has been trained based on the table obtained from the reference products.

[0163] The multivariate statistical algorithm used in the allocation step can be a partial least squares regression multivariate statistical algorithm; preferably, the multivariate statistical algorithm is selected from: partial least squares regression algorithm and partial least squares regression algorithm with discriminant analysis. This algorithm is usually a partial least squares regression algorithm, such as the PLS algorithm or the PLS-DA algorithm.

[0164] Based on the table obtained from the reference sample, the multivariate statistical algorithm used in the allocation step was trained.

[0165] In Partial Least Squares Discriminant Analysis (PLS-DA), prediction coefficients ranging from 0 to 1 represent the probability or confidence that a sample belongs to a particular class.

[0166] The following are the calculation and usage methods for this coefficient:

[0167] 1. Create latent variables:

[0168] PLS-DA creates latent variables (components) that capture the maximum variance of the data X (predictors) while maximizing the covariance with the category Y (categorical response).

[0169] 2. Calculate the score:

[0170] The samples are projected onto these latent variables, and the resulting scores are used to distinguish between categories.

[0171] 3. Modeling:

[0172] Based on these scores, a linear model is fitted to predict the Y value. In the case of PLS-DA, Y is typically binary encoded to represent the category (e.g., 0 for group A, 1 for group B).

[0173] 4. Prediction:

[0174] When making predictions for new samples, scores are calculated for these samples, and continuous predictions are achieved using a linear model. This continuous prediction is then converted into probabilities ranging from 0 to 1.

[0175] 5. Explanation of probability:

[0176] These probabilities are then interpreted to assign samples to different categories.

[0177] For example:

[0178] - If the probability is less than 0.4, the sample is classified into class A (in this case, secondary refined base oils).

[0179] - If the probability is greater than or equal to 0.4, the sample is classified into class B (conventional base oils).

[0180] Preferably, the secondary refined lubricating oil used in this invention meets the API classification standards for Group I, II, III, IV and / or V oils in terms of saturated compound content, sulfur content and viscosity index. Specifically, it meets the Group I, II, III and / or IV oil standards.

[0181] According to a particularly preferred embodiment, the at least one secondary refined lubricating oil used in this invention is selected from secondary refined lubricating oils whose characteristics meet the standards set by the API classification for Group I or Group II oils, particularly in terms of saturated compound content, sulfur content, and viscosity index.

[0182] On the other hand, the recycled lubricating oil used in this invention is formulated using waste lubricant, and therefore differs from virgin or new base oils (oils directly refined from petroleum) or natural base oils (e.g., naturally sourced) in terms of composition and physicochemical properties.

[0183] Specifically, as mentioned above, surprisingly, recycled lubricants exhibit superior thermophysical and hydraulic properties, particularly in terms of viscosity index, density, Noyak evaporation loss, flash point, and / or thermal conductivity, and advantageously, these thermophysical and hydraulic properties are superior to those of virgin base oils.

[0184] Preferably, the recycled lubricating oil used in this invention has a dynamic viscosity of 2-12 mmHg, measured at 100°C according to ASTM D445 standard. 2 / s -1 Specifically, 3-10 mm 2 / s -1 .

[0185] Preferably, the lubricating oil, at least partially refined, has a dynamic viscosity of 4.0 mmHg, measured at 100°C according to ASTM D445 standard. 2 / s, especially in the 4.0-12 mm range 2 Between / s, specifically greater than or equal to 4.3 mm 2 / s, more specifically in the range of 4.4-10 mm 2 Between / s, especially 5.0-6.5 mm 2 / s.

[0186] Preferably, the recycled lubricating oil used in this invention has a dynamic viscosity of 20-40 mm² / s, specifically 25-40 mm² / s, measured at 40°C according to ASTM D445 standard. 2 / s, more specifically 26-35 mm² / s.

[0187] Preferably, the viscosity index of the recycled lubricating oil used in this invention is greater than or equal to 110. Therefore, the viscosity index of the at least partially secondary refined lubricating oil varies between 110 and 130, specifically between 115 and 125.

[0188] The viscosity index can be determined according to the NF ISO 2909 standard.

[0189] Preferably, the Noyak evaporation loss of the regenerated lubricating oil used in this invention is less than or equal to 15%. Therefore, the Noyak evaporation loss of the at least partially secondary refined lubricating oil varies between 5% and 15%.

[0190] More specifically, the Noyak evaporation loss of the regenerated lubricating oil used in this invention is absolutely less than 12%, especially 5%-12%, and more specifically 6%-11.5%.

[0191] Noark evaporation losses can be determined in particular according to the CEC L-40-93 standard.

[0192] Preferably, the sulfur content of the recycled lubricating oil used in this invention varies between 0.001% and 0.2% by mass percentage in the total mass of the recycled lubricating oil, specifically between 0.01% and 0.2% by mass percentage, more specifically between 0.02% and 0.2% by mass percentage, and especially between 0.09% and 0.15% by mass percentage.

[0193] Preferably, the aromatic compound content of the recycled lubricating oil used in this invention accounts for a mass percentage greater than or equal to 0.01% of the total mass of the recycled lubricating oil, and more specifically, a mass percentage of 0.02%-10%.

[0194] The content of these various elements can be determined by any method known to those skilled in the art, such as X-ray fluorescence spectroscopy (XRF), infrared spectroscopy, or ultraviolet spectroscopy.

[0195] The secondary refined lubricating oil used in this invention advantageously possesses at least one, at least two, at least three, or even all of the following features:

[0196] - According to ASTM D445, the dynamic viscosity measured at 100°C is greater than or equal to 4.0 mm² / s, for example, varying between 4.0 and 12 mm² / s, more specifically 4.4 to 10 mm² / s;

[0197] - Viscosity index greater than or equal to 110, especially varying between 110 and 130, specifically between 115 and 125;

[0198] - Noah's evaporation loss is less than or equal to 15%, specifically varying between 5% and 15%, preferably absolutely less than 12%, more specifically between 5% and 12%, and more specifically between 6% and 11.5%;

[0199] - The sulfur content as a percentage of the total mass of the recycled lubricating oil varies between 0.001% and 0.2%, specifically between 0.01% and 0.2%, and particularly between 0.02% and 0.2%, especially between 0.09% and 0.15%.

[0200] - The content of aromatic compounds in the total mass of the regenerated lubricating oil is greater than or equal to 0.01%, and more specifically, the mass percentage is between 0.02% and 10%.

[0201] Preferably, the density of the recycled lubricating oil used in this invention is less than or equal to 870 kg / m³. 3 Specifically, less than 860 kg / m 3 Therefore, the density of at least partially secondary refined lubricating oil is 830-870 kg / m³. 3 The variation is between 840-860 kg / m³. 3 .

[0202] The specific density can be determined according to the NF EN ISO 12185 standard.

[0203] Preferably, the flash point of the recycled lubricating oil used in this invention is greater than or equal to 225°C, specifically greater than or equal to 228°C. Therefore, the flash point of at least some of the secondary refined lubricating oil can vary between 225°C and 245°C.

[0204] The specific flash point can be determined according to the NF EN ISO 2592 standard.

[0205] Preferably, the thermal conductivity of the regenerated lubricating oil used in this invention, measured at 100°C and atmospheric pressure, is greater than or equal to 125 mW / mK, specifically greater than or equal to 128 mW / mK. Therefore, the thermal conductivity of at least a portion of the secondary refined lubricating oil varies between 125-145 mW / mK, specifically 128-140 mW / mK.

[0206] This thermal conductivity can be determined in particular according to the ASTM D7896-19 standard.

[0207] Due to these properties in viscosity index, density, thermal conductivity, flash point, Noyak evaporation loss, and density, the secondary refined lubricating oil used in this invention exhibits excellent performance.

[0208] A high viscosity index, in particular, allows for a composition whose viscosity changes less with temperature.

[0209] Specifically, secondary refined lubricating oils advantageously have low density, specifically lower than that of virgin base oils, and high viscosity index, specifically higher than that of virgin base oils.

[0210] Specifically, at least some of the secondary refined lubricating oils are selected from oils sold by the following companies: Proluminas, Osilub, Tam house, Sahara, Enviroil, Cator, Setergo, Masafee, Southern Oil, Clenaway, Petrolube, Terrapure, Finas, Broad, Jungu, LWART, Tecoil, Osilub, Avista, Puraglobe, LPC Hellas, Itelyum, FFS Refiners, Tayras, ReGENIII, Safety Kleen, Daya Lubricant, Lubricon, IFP Petro, Plus Lubricant, or Pentas Flora.

[0211] Lubricating Composition

[0212] The at least one secondary refined lubricating oil may be used as the sole base oil of the lubricating composition, or may be formulated in combination with one or more different base oils, specifically in combination with one or more novel base oils.

[0213] These new base oils are specifically selected from base oils commonly used in the lubricant industry, such as mineral oils, synthetic oils or natural oils, animal oils or vegetable oils, or mixtures thereof.

[0214] Preferably, these base oils are mineral oils or synthetic oils belonging to categories I to V as defined by the API classification (or equivalent ATIEL classification), as shown in Table 1 below, or mixtures thereof.

[0215] Therefore, the lubricating composition used in this invention may comprise a mixture of one or more at least partially secondary refined lubricating oils and one or more novel base oils (e.g., at least one mineral oil).

[0216] Preferably, the lubricating composition of the present invention comprises a novel base oil that is different from a secondary refined lubricating oil, and its mass percentage is less than 50%.

[0217] Preferably, the lubricating composition of the present invention mainly consists of at least one secondary refined lubricating oil.

[0218] Specifically, the at least one secondary refined lubricating oil accounts for more than 50% by mass of the total mass of the composition containing at least one of the oils, especially more than 70% by mass, specifically more than 75% by mass, and preferably more than 80% by mass.

[0219] The at least one secondary refined lubricating oil accounts for more than 90% by mass of the total mass of oil or base oil in the composition containing at least one of the oils, more specifically 90%-100% by mass, and preferably 95%-100% by mass.

[0220] In one specific embodiment, the lubricating composition of the present invention is completely free of base oils other than the at least one secondary refined oil.

[0221] additive

[0222] In one specific embodiment, the composition used in this invention may also contain various additives suitable for use as lubricants, as detailed below, for example, for light or heavy vehicle power systems or water vehicle power systems, for internal combustion, electric or hybrid power systems.

[0223] These additives may be selected in particular from friction modifiers, anti-wear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD) additives, dispersants, defoamers, thickeners, preservatives, copper passivators, and mixtures thereof.

[0224] Preferably, the composition comprises one or more additives selected from viscosity index improvers, pour point depressants, anti-wear additives, antioxidants, and mixtures thereof.

[0225] These additives may be added to at least one of the regenerated base oils used in this invention, or to a mixture of the at least one regenerated base oil and at least one virgin base oil, in appropriate amounts as determined by those skilled in the art. It should be noted that the properties and quantities of the additives used are selected such that the advantageous properties of the composition based on the at least one secondary refined lubricating oil are not, or substantially not, altered by the considered addition.

[0226] Specifically, the composition may contain additives accounting for 0%-20% of the total weight of the composition, specifically 0.01%-10% by mass, as described above.

[0227] Specifically, the composition may contain at least one base oil comprising 80%-99.95% by weight of the total weight of the composition, which is composed of at least one partially secondary refined lubricating oil, preferably 80%-99.99% by weight, and optionally contains 0.01%-20% by weight of virgin lubricating oil, and preferably 0.05%-10% by weight of additives.

[0228] Therefore, according to another aspect, the present invention also relates to a method or process for preparing a lubricating composition, comprising at least the step of obtaining at least partially secondary refined lubricating oil from waste lubricant H.

[0229] Preferably, this method or process includes at least the following steps:

[0230] (i) Providing at least partially secondary refined lubricating oil obtained from waste lubricant, specifically by subjecting the waste lubricant to one or more steps, including dehydration, distillation, filtration, hydrogenation, liquid-liquid extraction, sedimentation and / or passing the waste lubricant through an adsorbent material, preferably as detailed above;

[0231] (ii) Optionally, the at least partially secondary refined lubricating oil is mixed with one or more novel base oils, which are different from the secondary refined lubricating oil, such as one or more mineral oils;

[0232] (iii) Optionally, at least one additive may be added to the lubricating oil that has been at least partially refined in step (i) or the lubricating oil mixture in step (ii), as described above.

[0233] application

[0234] Lubricating oils that are at least partially refined are particularly suitable for use in lubrication compositions.

[0235] As mentioned above, the use of secondary refined oils, preferably those whose characteristics are consistent with those specified by the API classification for Group I or Group II oils, is beneficial in allowing for reduced component wear, specifically reduced wear of moving parts, and more specifically, reduced mechanical fatigue pitting of moving parts in mechanical systems.

[0236] Specifically, the mechanical system can be a moving or stationary power system.

[0237] In the context of this invention, "power system" refers to a system comprising all the mechanical components required for a target moving or stationary application and powered by an engine. This can be an internal combustion, gas (especially hydrogen or ammonia), electric, or hybrid system, depending on the type of one or more engines included in the power system: an internal combustion engine, a gas (especially hydrogen or ammonia) engine, and / or an electric engine.

[0238] In the context of this invention, a "stationary" power system refers to a power system that includes a stationary engine. Such applications can be seen, for example, in power generation devices. Specifically, it can be a gas-powered system, and more specifically, a stationary gas engine.

[0239] More specifically, a "sporty" powertrain is a powertrain used in vehicles, including light vehicles, heavy vehicles, so-called "off-road" sports machinery, or water vehicles.

[0240] Therefore, a "sporty" powertrain can be a vehicle propulsion system, specifically an internal combustion engine vehicle, an electric vehicle, or a hybrid vehicle.

[0241] In the context of this invention, "propulsion system" refers to a system that includes mechanical components necessary for the propulsion of a vehicle. More specifically, a propulsion system includes an engine, such as an internal combustion engine or an electric motor, which includes a rotor-stator assembly with power electronics, a transmission, and optionally a battery.

[0242] The lubricating composition can therefore be used to lubricate gears, transmission mechanisms, especially reducers, gearboxes and / or axle shafts, and engines.

[0243] The secondary refined lubricating oil of the present invention can be used in lubricating compositions to lubricate various components of the propulsion system of electric or hybrid vehicles, specifically the engine, power electronics, transmission and / or battery, more specifically the bearings located between the stator and rotor of the motor, or the transmission, specifically the reducer of the electric or hybrid vehicle.

[0244] More specifically, they can be used to lubricate the motors in electric or hybrid vehicles. They can also provide lubrication for the bearings between the stator and rotor of the electric or hybrid vehicle motor.

[0245] Specifically, the composition based on at least one secondary refined oil used in this invention allows for lubrication of the transmission of electric or hybrid vehicles, specifically the reducer if a transmission is present.

[0246] Therefore, advantageously, for example by using a composition based on at least one secondary refined oil used in this invention, lubrication can be provided for the transmission of electric or hybrid vehicles, specifically for the reducer.

[0247] The present invention specifically relates to a method or process for reducing wear of components in a mechanical system, specifically reducing mechanical fatigue pitting of moving parts in a mechanical system, comprising at least the step of circulating a composition based on at least one partially secondary refined lubricating oil in the mechanical system, the composition being as described above.

[0248] This method or process specifically includes the following steps:

[0249] a) Provides a composition based on at least one at least partially secondary refined lubricating oil, as described above;

[0250] b) Using the composition described in step a) in a mechanical system, as specifically described above;

[0251] c) Circulate the composition in the mechanical system.

[0252] In this invention, the particular, beneficial, or preferred characteristics of these oils and compositions allow for the definition of uses within the invention, which also have particular, beneficial, or preferred characteristics.

[0253] The present invention will now be described through the following non-limiting embodiments.

[0254] Example

[0255] The measurement methods for the various parameters described in the embodiments will be explained in detail below.

[0256] Methods for measuring kinematic viscosity

[0257] The kinematic viscosity of the oil was measured using a viscometer at 40°C (KV40) and 100°C (KV100) according to NF EN ISO 3104 standard. This standard is technically equivalent to ASTM D445. Results are expressed in mm² / s (equivalent to centistokes, denoted as cSt).

[0258] Methods for measuring viscosity index

[0259] The viscosity index is a dimensionless ratio used to indicate how the viscosity of an oil changes with temperature. It is calculated according to the NF ISO 2909 standard using the kinematic viscosity values ​​at 40°C and 100°C. The higher the index, the less the oil's viscosity is affected by temperature changes.

[0260] Methods for measuring sulfur content and aromatic compound content

[0261] The sulfur content and aromatic compound content in oil products are determined by infrared or ultraviolet spectroscopy.

[0262] Methods for measuring acid value

[0263] Acid value, also known as Acid Number (AN), formerly known as Total Acid Number (TAN), is defined as the number of milligrams of potassium hydroxide (mg KOH / g) required to neutralize one gram of organic or inorganic acids contained in an oil.

[0264] The acid value of both new and waste oil products was measured using potentiometric titration according to ASTM D 664 standard (November 2018, 5th edition).

[0265] Methods for measuring pour point

[0266] The pour point of the composition was determined according to ASTM D5950 standard, in degrees Celsius.

[0267] Methods for measuring volatility

[0268] Volatility allows for the determination of an oil's evaporation loss at high temperatures. Volatility was determined using the Noark evaporation loss test according to CEC L-40-93 standard. During the test, the oil sample was heated to approximately 250°C under a constant gas flow for approximately 60 minutes.

[0269] The results are expressed as a weight loss fraction, in units of mass percentage.

[0270] Methods for measuring density

[0271] The density of the oil was determined according to NF EN ISO 12185 standard at 15°C using a U-tube densitometer. The unit is kg / m³. 3 .

[0272] Methods for measuring thermal conductivity

[0273] Thermal conductivity, usually denoted by λ, characterizes the ability of an oil to dissipate heat in a medium. Thermal conductivity is determined according to standard ASTM D7896-19 using the transient thermal conductivity method for liquid hot wires. Its unit is mW / mK.

[0274] Flash point measurement method

[0275] Flash point provides an indication of a product's ability to form a flammable mixture with air under controlled conditions. It is determined using a Cleveland open-cup apparatus according to NFEN ISO 2592 standards. The flash point at ambient atmospheric pressure is the lowest temperature at which the vapor above the surface of the oil ignites when a flame passes over the oil-containing test cup. It is measured in degrees Celsius.

[0276] Measurement of mechanical fatigue pitting

[0277] Mechanical fatigue pitting (or "pitting") is evaluated using an MPR (Micro Pitting Rig) friction testing machine.

[0278] The MPR friction testing machine is a device that brings a central roller (12 mm in diameter) into contact with three rings (54 mm in diameter) arranged around the central roller. This geometry allows the test roller to undergo multiple rolling contacts in a short period of testing, thereby accelerating mechanical fatigue pitting.

[0279] Mechanical fatigue pitting was detected using an accelerometer connected to a vibration monitor. The test was stopped when the vibration setpoint was exceeded due to pitting. Two to three tests were performed for each composition. The time required to reach the vibration setpoint was recorded for each test.

[0280] The longer the test time, that is, the longer it takes to reach the vibration set value, the better the performance of the tested composition in terms of mechanical fatigue pitting.

[0281] Example 1

[0282] The properties of commercially available lubricating compositions I1 and I2 conforming to the present invention were evaluated, which contain at least partially secondary refined lubricating oil H.

[0283] Another commercially available lubricating composition I3 conforming to the present invention was also evaluated, which comprises at least partially secondary refined lubricating oil J.

[0284] At least partially secondary refined oil product H is obtained from waste lubricating composition (which contains a large amount of base oil) and is subjected to at least one step of dehydration, distillation, filtration, hydrogenation, liquid-liquid extraction, sedimentation and / or passing the waste lubricating oil through an adsorbent material, especially at least one step of dehydration, distillation, liquid-liquid extraction and / or hydrogenation.

[0285] At least partially secondary refined oil J is obtained from waste lubricating composition (which contains a large amount of base oil) and is subjected to at least one step of dehydration, distillation, filtration, hydrogenation, liquid-liquid extraction, sedimentation and / or passing the waste lubricating oil through an adsorbent material, especially at least one step of dehydration, distillation, liquid-liquid extraction and / or hydrogenation.

[0286] Composition C1, based solely on virgin / primary base oils, was also evaluated. This composition does not conform to the present invention because it has not undergone any recycling or secondary refining processes. This composition contains commercially available base oils classified as API Group I.

[0287] Composition I1 comprises 25% new / virgin oil and 75% oil H as defined above.

[0288] Composition I2 does not contain any new oil, and therefore only contains oil H as defined above.

[0289] Composition I3 comprises 25% new / virgin oil and 75% oil J as defined above.

[0290] The kinetic viscosity, viscosity index, density at 15°C, Noark evaporation loss, and Cleveland flash point of oils H and J were measured according to the scheme described above. The results are shown in Table 2 below.

[0291] [Table 2]

[0292]

[0293] The kinetic viscosity, viscosity index, sulfur content, acid value, and pour point of the compositions C1, I1, I2, and I3 at 40°C and 100°C were measured according to the scheme described above. The results are shown in Table 3 below.

[0294] [Table 3]

[0295]

[0296] The mechanical fatigue pitting corrosion performance of the composition was tested according to the mechanical fatigue pitting corrosion test described above. The results are shown in Table 4 below.

[0297] [Table 4]

[0298]

[0299] It has been observed that the secondary refined lubricating oil of the present invention exhibits resistance to mechanical fatigue pitting in the lubricating composition, which is comparable to or even significantly superior to that of a brand new lubricating oil.

[0300] Specifically, the results obtained using composition I1 of the present invention are comparable to those obtained using reference composition C1. Furthermore, surprising results were also obtained using composition I2 of the present invention, which does not contain virgin oil. Therefore, for composition I2, the maximum set test time (750 hours) was achieved when all three tests were completed.

[0301] Moreover, when using a secondary refined natural lubricating oil (which accounts for 75% of the total weight of the oil contained in lubricating composition I3) that is different from the oil used in I1 and I2, composition I3 yielded even more impressive results, with the longest test time averaging 2750 hours, and no maximum threshold was set this time.

Claims

1. At least one at least partially secondary refined lubricating oil for use in reducing wear on components in a mechanical system, specifically for reducing wear on moving parts in a mechanical system.

2. The use according to claim 1, for reducing mechanical fatigue pitting of moving parts in a mechanical system.

3. The use according to any one of the preceding claims, wherein the at least one partially secondary refined lubricating oil is obtained from waste lubricant after one or more pretreatment steps, including dehydration, distillation, filtration, hydrogenation, liquid-liquid extraction, sedimentation and / or passing the waste lubricating oil through an adsorbent material.

4. The use according to any one of the preceding claims, wherein the at least one at least partially secondary refined lubricating oil is used in the composition, wherein its content accounts for less than 50% by mass of the total mass of the composition, specifically less than 70% by mass, particularly less than 75% by mass, and more specifically less than 80% by mass.

5. The use according to any one of the preceding claims, wherein the at least one at least partially secondary refined lubricating oil has a dynamic viscosity greater than or equal to 4.0 mm², measured at 100°C according to ASTM D445 standard. 2 / s, especially in the 4.0-12 mm range 2 The variation is between / s, specifically greater than or equal to 4.3 mm. 2 / s, more specifically in the range of 4.4-10mm 2 Variations between / s, especially between 5.0 and 6.5 mm 2 / s.

6. In the use according to any one of the preceding claims, the viscosity index of the at least one at least partially secondary refined lubricating oil is greater than or equal to 110, particularly varying between 110 and 130, specifically 115-125.

7. In the use according to any one of the preceding claims, the Noyak evaporation loss of the at least one at least partially secondary refined lubricating oil is strictly less than 12%, especially 5%-12%, and more specifically 6%-11.5%.

8. In the use according to any one of the preceding claims, the sulfur content of the at least one partially secondary refined lubricating oil accounts for a mass percentage of 0.001%-0.2% of the total mass of the regenerated lubricating oil, specifically 0.01%-0.2% by mass.

9. In the use according to any one of the preceding claims, the aromatic compound content of the at least one partially secondary refined lubricating oil accounts for a mass percentage greater than or equal to 0.01% of the total mass of the regenerated lubricating oil, and more specifically, a mass percentage of 0.02%-10%.

10. In the use according to any one of the preceding claims, the density of the at least one at least partially secondary refined lubricating oil is less than or equal to 870 kg / m³. 3 Especially at 830-870 kg / m 3 Between, specifically less than or equal to 860 kg / m 3 More specifically, in the range of 840-860 kg / m 3 between.

11. In the use according to any one of the preceding claims, the at least one partially secondary refined lubricating oil has an alkylphenol content of 5-3200 ppm, specifically 10-2000 ppm, preferably 15-1500 ppm.

12. The use according to any one of the preceding claims, wherein the at least one at least partially secondary refined lubricating oil comprises one or more polyolefin alkanes (PAOs) containing less than 40 carbon atoms, preferably 30 carbon atoms.

13. The use according to any one of the preceding claims, wherein the at least one partially secondary refined lubricating oil is used in a composition comprising one or more base oils different from the at least partially secondary refined lubricating oil and / or one or more additives, the additives being particularly selected from corrosion inhibitors, friction modifiers, extreme pressure additives, anti-wear additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPDs), dispersants, defoamers, and mixtures thereof.

14. Use of at least one lubricating composition for reducing wear of components in a mechanical system, said at least one lubricating composition comprising at least one at least partially secondary refined lubricating oil as described in any one of claims 3-12, specifically for reducing wear of moving parts in a mechanical system, and more specifically for reducing mechanical fatigue pitting of moving parts in a mechanical system.

15. A method for reducing wear of components in a mechanical system, specifically a method for reducing mechanical fatigue pitting of moving parts in a mechanical system, comprising at least the step of circulating a composition based on at least one at least partially secondary refined lubricating oil in the mechanical system, said lubricating oil being as described in any one of claims 3 to 12.

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