Diester-based lubricant composition

Abstract

Diester lubricating composition The present invention relates to - one or more diesters, each of said diesters being · a diol selected from 1,2-propanediol, 1,2-decanediol and 1,3-diols having 3 to 10 carbon atoms, and · two same or different monocarboxylic acids having a straight-chain or branched-chain hydrocarbon chain having 4 to 10 carbon atoms a diester formed therebetween, and - at least one base oil different from the diester and / or at least one additive different from the diester, said additive being selected from friction modifier additives, antiwear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, antifoaming agents, thickeners, corrosion inhibitors, copper passivators and mixtures thereof, at least one base oil and / or at least one additive and relates to a lubricating composition containing the same.

Description

Technical Field

[0001] The present invention relates to the field of compositions for lubricating and / or cooling components of mobile or stationary systems such as heavy or light vehicles, utility vehicles, or energy storage devices. More particularly, it relates to the use of novel compounds such as diesters in cooling and / or lubricating compositions, and in particular to the use of novel compounds used in heavy or light vehicles, utility machines, or energy storage devices.

Background Art

[0002] Lubricating compositions, also known as "lubricants", are generally used in various components of motor vehicles, mainly for the purpose of reducing the frictional force between components, more particularly between different metal parts moving within engines, transmissions and hydraulic circuits. Furthermore, lubricating compositions are effective in preventing premature wear or damage of such parts, especially their surfaces. For this purpose, lubricating compositions have conventionally been composed of base oils, which generally have a plurality of additives attached thereto, for example friction modifier additives, to stimulate the lubricating performance of the base oil and also to obtain further performance.

[0003] Lubricating compositions for transmissions (e.g., gearboxes or axles) must meet many requirements, particularly with respect to the stringent specifications imposed by motor vehicle manufacturers. More particularly, the lubricating composition must have satisfactory properties suitable for the implementation of transmission components within the vehicle, particularly in gearboxes or axles, with respect to viscosity, viscosity-temperature resistance, low temperature performance, etc.

[0004] Lubricating compositions, also called cooling compositions, can also be used in energy storage devices such as data centers.

[0005] There is a need to provide lubricating and / or cooling compositions of renewable plant origin with low environmental impact.

[0006] Furthermore, due to current environmental concerns, especially aimed at reducing carbon dioxide emissions, there is an urgent need to reduce the fuel consumption of automobiles. Thus, it is known that lubricating compositions correspond to effective means acting on fuel consumption through their influence on the frictional forces occurring between various components of an automobile. Thereby, it is necessary to develop lubricants that reduce the friction of gearboxes and axle differentials.

[0007] Improving the "fuel consumption" characteristics of transmission lubricants while maintaining the required high level of performance remains a challenge.

[0008] As an example of a lubricant for transmissions, in order to save fuel, at least 30% by weight of one or more methyl esters of fatty acids of the formula RCOOCH3 (wherein R is a paraffin or olefin moiety having 11 to 23 carbon atoms) are used in combination with one or more phosphorus, sulfur or phosphorus-sulfur antiwear and / or extreme pressure additives, and a polyalphaolefin to formulate a lubricating composition for a gearbox. International Publication No. WO 2010 / 038147 can be cited.

[0009] 1.5 mm at 100 °C 2 / s to 3.5 mm 2 / s and having a kinematic viscosity in the range of 3% to 10% of 2 mm at 100 °C 2 / s to 10 mm 2 / s and a transmission lubricating composition showing an improvement in "fuel consumption" containing a monoester type oil having a kinematic viscosity in the range and an ester type oil providing sulfur is also described in US Patent Application Publication No. US 2017 / 0145337.

[0010] The object of the present invention is to propose a novel lubricating composition having improved characteristics with respect to friction reduction or cooling characteristics.

[0011] The present invention also provides a novel lubricating composition that satisfies the properties required for its implementation for lubricating transmission components of light or heavy motor vehicles, such as gearboxes and axles, and exhibits improved properties with respect to fuel economy (the "fuel consumption" property), and more particularly good performance with respect to low temperature properties. SUMMARY OF THE INVENTION

[0012] Accordingly, the subject of the present invention is mainly - one or more diesters, each of said diesters being o a diol selected from 1,2-propanediol, 1,2-decanediol and 1,3-diols having from 3 to 10 carbon atoms, o two identical or different monocarboxylic acids having a straight-chain or branched hydrocarbon chain having from 4 to 10 carbon atoms and formed between them, a diester, - at least one base oil different from the diester and / or at least one additive different from the diester, said additive being selected from friction modifier additives, antiwear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, antifoaming agents, thickeners, corrosion inhibitors, copper passivators and mixtures thereof, at least one base oil and / or at least one additive comprising a lubricating composition.

[0013] According to one embodiment, the lubricating composition according to the invention is with respect to the total weight of the composition - 5 to 95% by weight, preferably 10 to 90% by weight, otherwise preferably 20 to 80% by weight, even more preferably 30 to 70% by weight, or even 40 to 60% by weight of said one or more diesters, - 1 to 95% by weight, preferably 10 to 90% by weight, more preferably 20 to 80% by weight, otherwise more preferentially 30 to 70% by weight, or even 40 to 60% by weight of one or more base oils different from said diesters, - Optionally, one or more additives different from diesters and different from base oils in an amount of 0.01 to 20% by weight, preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, even more preferably 0.5 to 7% by weight, or even more preferably 1 to 5% by weight are included.

[0014] According to one embodiment, the lubricating composition according to the present invention is based on the total weight of the composition - at least 5% by weight, preferably at least 10% by weight, preferably at least 30% by weight, preferably at least 50% by weight, more preferably at least 70% by weight, or even more preferably at least 90% by weight of one or more diesters, and - 0.01 to 20% by weight, preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, even more preferably 0.5 to 7% by weight, or even more preferably 1 to 5% by weight of one or more additives selected from friction modifiers, antiwear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, antifoaming agents, thickeners, corrosion inhibitors, copper thickeners, and mixtures thereof, and - Optionally, 5 to 94% by weight, preferably 10 to 94% by weight, preferably 15 to 90% by weight of a base oil different from the diesters according to the present invention are included.

[0015] Preferably, the diester contains carbon atoms of 13 to 25 carbon atoms, preferably 13 to 24 carbon atoms.

[0016] Preferably, the kinematic viscosity of the diester is in the range of 1 to 6 mm 2 / s at 100 °C, preferably in the range of 1 to 4 mm 2 / s.

[0017] Preferably, the diol is selected from 1,2-propanediol, 1,2-decanediol, and 1,3-alkanediols having 3 to 7 carbon atoms, preferably from 1,2-propanediol and 1,3-propanediol; otherwise, preferably the diol is 1,2-propanediol.

[0018] Preferably, the monocarboxylic acid contains a linear hydrocarbon chain having 4 to 10 carbon atoms, preferably 5 to 9 carbon atoms, either the same or different.

[0019] Preferably, the diester is - a diester formed from 1,2-decanediol and two heptanoic acids, - a diester formed from 1,2-decanediol and two pentanoic acids, - a diester formed from 1,2-propanediol and two heptanoic acids, - a diester formed from 1,2-propanediol and two nonanoic acids, - a diester formed from 1,3-propanediol and two heptanoic acids, - a diester formed from 1,2-propanediol and two octanoic acids, - a diester formed from 1,2-propanediol and two decanoic acids, - a diester formed from 1,2-propanediol, octanoic acid, and decanoic acid, - and mixtures thereof selected from.

[0020] Preferably, the lubricating composition according to the present invention is - one or more diesters, o· a diol selected from 1,2-decanediol and 1,3-propanediol, and · two identical or different monocarboxylic acids having a linear or branched hydrocarbon chain having 4 to 10 carbon atoms formed therebetween, as well as Diesters formed from 1,2 - propanediol and two heptanoic acids, Diesters formed from 1,2 - propanediol and two octanoic acids, Diesters formed from 1,2 - propanediol and two decanoic acids, Diesters formed from 1,2 - propanediol, octanoic acid, and decanoic acid, and mixtures thereof selected from the group consisting of diesters, at least one base oil different from the diester and / or at least one additive different from the diester, wherein the additive is selected from friction modifier additives, anti - wear additives, extreme - pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, defoamers, thickeners, corrosion inhibitors, copper passivators, and mixtures thereof, at least one base oil and / or at least one additive comprising.

[0021] The present invention further relates to the use of at least one diester in a lubricating composition, wherein the diester is selected from the group consisting of diols selected from 1,2 - propanediol, 1,2 - decanediol, and 1,3 - diols having from 3 to 10 carbon atoms, and two same or different monocarboxylic acids having a straight - chain or branched - chain hydrocarbon chain having from 4 to 10 carbon atoms formed therebetween, wherein the lubricating composition further comprises at least one base oil different from the diester and / or at least one additive different from the diester, wherein the additive is selected from friction modifier additives, anti - wear additives, extreme - pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, defoamers, thickeners, corrosion inhibitors, copper passivators, and mixtures thereof, at least one base oil and / or at least one additive, relating to the use.

[0022] According to one embodiment, the at least one diester is used to lubricate and / or cool at least one element of a mobile or stationary system selected, for example, from heavy or light vehicles, utility vehicles, and energy storage systems.

[0023] Preferably, the mobile system is a vehicle, and the lubricating composition is used to reduce the fuel consumption of a vehicle equipped with transmission components lubricated by the composition, particularly the fuel consumption of the gearbox and / or the axles.

[0024] Preferably, the diester used in the use according to the invention is as defined within the framework of the lubricating composition according to the invention, and / or the lubricating composition used in the use according to the invention is as defined within the framework of the lubricating composition according to the invention.

[0025] According to one embodiment, the present invention relates to the use of at least one diester in a lubricating composition for lubricating and / or cooling at least one element of a mobile or stationary system selected from utility vehicles, and energy storage systems, wherein the diester is - selected from diols including 1,2-propanediol, 1,2-decanediol, and 1,3-diols having 3 to 10 carbon atoms, and - two identical or different monocarboxylic acids having a linear or branched hydrocarbon chain having 4 to 10 carbon atoms formed therebetween, and the lubricating composition further comprises at least one base oil different from the diester and / or at least one additive different from the diester, wherein the additive is selected from friction modifier additives, antiwear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, antifoaming agents, thickeners, corrosion inhibitors, copper passivators, and mixtures thereof, relating to the use.

[0026] According to one embodiment, the present invention is the use of at least one diester in a lubricating composition for lubricating and / or cooling at least one element of a mobile system, wherein said system is a vehicle, wherein said diester is - a diol selected from 1,2-propanediol, 1,2-decanediol and 1,3-diols having from 3 to 10 carbon atoms, - two identical or different monocarboxylic acids having a straight-chain or branched hydrocarbon chain having from 4 to 10 carbon atoms formed therebetween, wherein said lubricating composition is at least one base oil different from the diester and / or at least one additive different from the diester, said additive being selected from friction modifiers, antiwear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, antifoaming agents, thickeners, corrosion inhibitors, copper passivators and mixtures thereof, further comprising at least one base oil and / or at least one additive, said lubricating composition being used to reduce the fuel consumption of a vehicle equipped with transmission components lubricated with the composition, in particular a gearbox and / or an axle, relating to use.

[0027] Hereinafter, in the present text, the expressions "comprised between... and...", "in the range of... to..." and "varying from... to..." are equivalent and mean that the limit values are included, unless otherwise specified.

[0028] Unless otherwise specified, the expression "comprising a" shall be understood as "comprising at least one".

DETAILED DESCRIPTION OF THE INVENTION

[0029] First of all, the present invention is - A diol selected from 1,2 - propanediol, 1,2 - decanediol, and 1,3 - diols having 3 to 10 carbon atoms, and - Two same or different monocarboxylic acids having a linear or branched hydrocarbon chain with 4 to 10 carbon atoms At least one diester formed therebetween, - At least one component selected from a base oil different from the diester, an additive different from the diester, and a mixture thereof, wherein when the additive is present, it is selected from a friction modifier additive, an anti - wear additive, an extreme - pressure additive, a detergent, an antioxidant, a viscosity index (VI) improver, a pour point depressant (PPD), a dispersant, an antifoaming agent, a thickener, a corrosion inhibitor, a copper passivator, and a mixture thereof, at least one component Relates to a lubricating composition containing the same.

[0030] The lubricating composition according to the present invention may contain one or more diesters, and each of the diesters is - A diol selected from 1,2 - propanediol, 1,2 - decanediol, and 1,3 - diols having 3 to 10 carbon atoms, and - The same or different monocarboxylic acids having a linear or branched hydrocarbon chain with 5 to 10 carbon atoms Formed therebetween, More specifically, it is possible to prepare a mixture of diesters by reacting a mixture of a diol and a monocarboxylic acid.

[0031] For example, a diol can be reacted with three monocarboxylic acids A1, A2, and A3. Thereby, according to such an example, the mixture of diesters falling within the scope of the present invention is - The diester formed between the diol and two acids A1, - The diester formed between the diol and two acids A2, - The diester formed between the diol and two acids A3, - The diester formed between the diol, acid A1, and acid A2, - Diesters formed between the diol and acid A1 and acid A3, - Diesters formed between the diol and acid A2 and acid A3 can be included.

[0032] The diesters used according to the present invention As described above, the diesters used according to the present invention are formed between a diol and two monocarboxylic acids.

[0033] The "diester formed between a diol and two monocarboxylic acids" defined by the present invention refers to a compound obtained by two esterification reactions, and each esterification reaction is carried out between one of the two alcohol functional groups of the diol and one of the acid functional groups of the two monocarboxylic acids.

[0034] According to a preferred embodiment, the diester has 13 to 25 carbon atoms, preferably 15 to 24 carbon atoms.

[0035] The diol used in the present invention is among 1,2-propanediol, 1,2-decanediol, and 1,3-diols containing 3 to 10 carbon atoms.

[0036] "Diol" refers to a compound containing (exactly) two hydroxyl functional groups (-OH).

[0037] "1,3-diol containing X to Y carbon atoms" means a diol in which the alcohol functional groups are located at the 1st and 3rd positions of a hydrocarbon chain containing X to Y carbon atoms, respectively.

[0038] The "hydrocarbon chain" defined by the present invention refers to a straight-chain or branched-chain, saturated or unsaturated alkyl or alkylene chain. The hydrocarbon chain may be optionally interrupted by one or more heteroatoms, more specifically one or more oxygen atoms. Preferably, the hydrocarbon chain is a straight-chain or branched-chain, saturated or unsaturated alkyl or alkylene chain consisting of carbon atoms and hydrogen atoms.

[0039] According to one embodiment, the 1,3-diol having 3 to 10 carbon atoms is selected from 1,3-alkanediols having 3 to 10 carbon atoms.

[0040] "1,3-alkanediol having X to Y carbon atoms" means a diol in which alcohol functional groups are located at the 1-position and 3-position of an alkane chain having X to Y carbon atoms, respectively.

[0041] According to one embodiment, the diol is selected from 1,2-propanediol, 1,2-decanediol, and 1,3-diols having 3 to 7 carbon atoms, preferably from 1,2-propanediol and 1,3-alkanediols having 3 to 7 carbon atoms, more preferably from 1,2-propanediol and 1,3-propanediol, and advantageously the diol is 1,2-propanediol.

[0042] The diol used according to the present invention may be commercially available or may be synthesized according to any method well known to those skilled in the art.

[0043] Preferably, the diol used according to the present invention contains a carbon content of biological origin of at least 60% by weight, preferably at least 70% by weight, alternatively preferably at least 80% by weight, alternatively more preferably at least 90% by weight, based on the total weight of the carbon atoms of the diol.

[0044] Within the framework of the present invention, the carbon content of biological origin can be measured according to the ASTM D6866 standard.

[0045] The diester used according to the present invention is obtained from two identical or different monocarboxylic acids.

[0046] "Monocarboxylic acid" means a compound containing a single carboxyl functional group (-COOH).

[0047] The hydroxycarboxylic acid used to form the diester of the present invention is selected from monocarboxylic acids having a straight-chain hydrocarbon chain with 4 to 10 carbon atoms, preferably 5 to 9 carbon atoms, or preferably 5 to 8 carbon atoms if not. Preferably, the straight-chain or branched-chain hydrocarbon chain of the monocarboxylic acid is saturated.

[0048] According to an embodiment, the monocarboxylic acid, either the same or different, contains a straight-chain hydrocarbon chain having 5 to 10 carbon atoms, preferably 5 to 9 carbon atoms, or preferably 5 to 8 carbon atoms if not.

[0049] According to an embodiment, the monocarboxylic acid, either the same or different, contains a saturated straight-chain hydrocarbon chain having 5 to 10 carbon atoms, preferably 5 to 9 carbon atoms, or preferably 5 to 8 carbon atoms if not.

[0050] The monocarboxylic acid used according to the present invention may be commercially available or may be synthesized according to any method known to those skilled in the art.

[0051] Preferably, the monocarboxylic acid used according to the present invention contains a carbon content of at least 60% by weight, preferably at least 70% by weight, or preferably at least 80% by weight, or more preferably at least 90% by weight of biological origin with respect to the total weight of the carbon atoms of the diol.

[0052] Preferably, the diester used in the present invention is saturated.

[0053] The "saturated diester" defined by the present invention means a diester having a saturated hydrocarbon chain. Thus, preferably, the diol used according to the present invention contains a saturated hydrocarbon chain, and the monocarboxylic acids used according to the present invention each contain a saturated hydrocarbon chain. Preferably, the hydrocarbon chain consists of carbon atoms and hydrogen atoms.

[0054] According to certain embodiments, the diesters used in accordance with the present invention are branched-chain diesters.

[0055] As used herein, the term "branched-chain diester" refers to a diester having a branched hydrocarbon chain that can be located between the two ester functional groups and / or at one or both ends of the diester.

[0056] According to a preferred embodiment, the diesters used in the present invention are saturated and branched.

[0057] According to an embodiment, the diesters used in accordance with the present invention have a kinematic viscosity in the range of 1 to 6 mm 2 / s, preferably 1 to 4 mm 2 / s, as measured at 100 °C in accordance with ASTM D445 standard.

[0058] According to an embodiment, the diesters according to the present invention have a kinematic viscosity in the range of 2 to 20 mm 2 / s, preferably 3 to 10 mm 2 / s, as measured at 40 °C in accordance with ASTM D445 standard.

[0059] It is understood that the definitions given above for carboxylic acids and alcohols can be combined, to the extent possible, to define other specific embodiments.

[0060] More particularly, the diesters used in accordance with the present invention are of the following formula (I), (II) or (III):

Chemical formula

Chemical formula

Chemical formula

[0061] Preferably, the diester corresponding to formula (I), (II) or (III) has 13 to 25 carbon atoms, preferably 15 to 24 carbon atoms.

[0062] In the diesters of formula (I), (II) or (III), R 1 and R 2 may be the same or different.

[0063] According to one embodiment, the diesters used according to the present invention are - a diester formed from 1,2 - decanediol and two heptanoic acids, - a diester formed from 1,2 - decanediol and two pentanoic acids, - a diester formed from 1,2 - propanediol and two heptanoic acids, - a diester formed from 1,2 - propanediol and two nonanoic acids, - a diester formed from 1,3 - propanediol and two heptanoic acids, - a diester formed from 1,2 - propanediol and two octanoic acids, - a diester formed from 1,2 - propanediol and two decanoic acids, - A diester formed from 1,2-propanediol and a mixture of acids including octanoic acid and decanoic acid, as well as mixtures thereof are selected from.

[0064] The diesters according to the present invention can be prepared according to synthetic methods known to those skilled in the art. The synthetic method uses, more specifically, two esterification reactions, each of which takes place between the alcohol functional group of the diol and the acid functional group of the monocarboxylic acid.

[0065] Of course, it is the role of those skilled in the art to adjust the synthetic conditions to obtain the diesters according to the present invention.

[0066] Within the framework of the present invention, it is understood that the diesters according to the present invention can be in the form of a mixture of at least two diesters according to the present invention, more specifically in the form of the diesters defined above.

[0067] Preferably, the diesters used according to the present invention contain a carbon content of biological origin of at least 60% by weight, preferably at least 70% by weight, otherwise preferably at least 80% by weight, otherwise more preferably at least 90% by weight, based on the total weight of the carbon atoms of the diester.

[0068] Within the framework of the present invention, the carbon content of biological origin can be measured according to the ASTM D6866 standard.

[0069] The diesters or mixtures of diesters according to the present invention can correspond to at least 5% by weight of the composition according to the present invention, preferably at least 10% by weight, preferably at least 30% by weight, more preferably at least 50% by weight, otherwise more preferably at least 70% by weight, more specifically at least 80% by weight, more specifically at least 90% by weight, or even at least 95% by weight of the total weight of the composition according to the present invention.

[0070] The diesters according to the present invention can be used together with one or more auxiliary base oils (also called co-base oils). According to one embodiment, the composition comprises, based on the total weight of the diester and a base oil different from the diester, - 5 to 95% by weight, preferably 5 to 50% by weight, more preferably 10 to 40% by weight of one or more diesters according to the present invention, and - 5 to 95% by weight, preferably 50 to 95% by weight, preferably 60 to 90% by weight of one or more different base oils according to the present invention and contains.

[0071] According to one embodiment, the lubricating composition according to the present invention may comprise, based on the total weight of the said composition, at least 30% by weight, more particularly 50% to 99.5% by weight, preferably 70% to 99% by weight, more preferably 80% to 99% by weight, or even 80% to 95% by weight of the diester or mixture of diesters according to the present invention.

[0072] According to certain embodiments, the lubricating composition according to the present invention can be formed up to more than 95% by weight, more particularly up to more than 98% by weight of one or more diesters according to the present invention.

[0073] According to certain embodiments, the composition according to the present invention is a composition comprising a 100% by weight mixture of a diester as defined in the present invention and an additional base oil, preferably the composition is, based on the total weight of the composition, - 5 to 95% by weight, preferably 5 to 50% by weight, more preferably 10 to 40% by weight of one or more diesters according to the present invention, and - 5 to 95% by weight, preferably 50 to 95% by weight, preferably 60 to 90% by weight of one or more different base oils according to the present invention and is a composition in the proportions containing.

[0074] Such embodiments are particularly advantageous when the composition is used for cooling as a cooling fluid.

[0075] Auxiliary base oil (common base oil) The lubricating composition according to the present invention may contain, in addition to one or more diesters according to the present invention, one or more base oils different from the diesters according to the present invention, which are called "auxiliary base oils".

[0076] The one or more base oils optionally present in the lubricating composition according to the present invention are appropriately selected with respect to their compatibility with the one or more diesters used according to the present invention.

[0077] A mixture of a plurality of base oils, for example, a mixture of 2, 3, or 4 base oils may be present.

[0078] Preferably, the base oil or mixture of auxiliary base oils used in the lubricating composition according to the present invention has a kinematic viscosity in the range of 1.5 to 8 mm 2 / s, particularly 1.5 to 6.1 mm 2 / s, more particularly 1.5 to 4.1 mm 2 / s, even more particularly 1.5 to 2.1 mm 2 / s as measured at 100 °C according to the ASTM D445 standard.

[0079] The base oil is defined by the API classification (or its equivalent according to the ATIEL classification) and can be selected from mineral oils or synthetic oils belonging to Groups I to V according to the classes shown in Table 1 below.

Table 1

[0080] Examples of mineral base oils include any type of base oil obtained by purification operations such as atmospheric distillation and vacuum distillation of crude oil, subsequent solvent extraction, dewaxing, solvent dewaxing, hydrotreating, hydrocracking, hydroisomerization, and hydrofinishing.

[0081] A mixture of synthetic oil and mineral oil, which may be biosourced, can be further used.

[0082] The base oil can be further selected from synthetic oils different from the esters defined by the present invention, such as certain carboxylic acid esters and alcohol esters, from polyalphaolefins (PAO), and from polyalkylene glycols (PAG) obtained by polymerization or copolymerization of alkylene oxides containing 2 to 8 carbon atoms, more particularly 2 to 4 carbon atoms.

[0083] The PAO used as the base oil is obtained, for example, from monomers containing 4 to 32 carbon atoms, such as octene or decene.

[0084] The weight average molecular weight of the PAO can vary quite widely. Preferentially, the weight average molecular weight of the PAO is less than 600 Da. The weight average molecular weight of the PAO can further be in the range of 100 - 600 Da, 150 - 600 Da, or further 200 - 600 Da.

[0085] For example, the PAO used in the context of the present invention, having a kinematic viscosity measured at 100 °C according to the ASTM D445 standard in the range of 1.5 - 8 mm 2 / s, is commercially available from Ineos under the trademarks Durasyn® 162, Durasyn® 164, Durasyn® 166 and Durasyn® 168.

[0086] Advantageously, the additional one or more base oils are selected from polyalphaolefins (PAO).

[0087] It is the role of the person skilled in the art to adjust the content of the auxiliary base oil used in the composition according to the present invention.

[0088] More particularly, the composition according to the present invention can contain 5 - 95% by weight, preferably 50 - 95% by weight, or preferably 60 - 90% by weight, of one or more base oils different from the diesters according to the present invention, based on the total weight of the composition.

[0089] Additives The lubricating composition according to the present invention may optionally further contain one or more additives known to those skilled in the art in the field of lubrication, more particularly in the field of lubrication for vehicle transmissions, especially for light or heavy vehicle transmissions.

[0090] The additives may be selected in particular from friction modifier additives, antiwear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, antifoaming agents, thickeners, corrosion inhibitors, copper passivators and mixtures thereof.

[0091] Preferably, the lubricating composition according to the present invention may further contain one or more additives selected from antioxidants, antifoaming agents, pour point improvers and corrosion inhibitors.

[0092] It is understood that the nature and amount of the additives used are selected so as not to affect the properties of the lubricating composition imparted by the diesters according to the present invention.

[0093] Such additives can be introduced separately and / or as a mixture similar to additives already commercially available for commercial lubricant formulations for vehicle engines having performance levels defined by ACEA (European Automobile Manufacturers' Association) and / or API (American Petroleum Institute) well known to those skilled in the art.

[0094] The additives may be present in the lubricating composition according to the present invention in a content within the range of 10% by weight or less, more particularly 5% by weight or less, more particularly 0.01 to 3% by weight, based on the total weight of the composition.

[0095] The lubricating composition according to the present invention may further contain at least one antioxidant additive.

[0096] Thereby, according to one of its aspects, the present invention relates to a lubricating composition comprising (i) at least one diester as defined above and (ii) at least one antioxidant additive.

[0097] Antioxidant additives generally make it possible to retard the decomposition of the composition in use. Such decomposition very often appears as the formation of deposits in the presence of sludge or in the increase of the viscosity of the composition.

[0098] Antioxidant additives act in particular as radical inhibitors or hydroperoxide decomposers.

[0099] Generally used antioxidant additives include phenolic antioxidants, amine antioxidant additives, and phosphorus-sulfur antioxidant additives. Some of such antioxidant additives, for example phosphorus-sulfur antioxidant additives, may produce ash. Phenolic antioxidant additives may be ash-free or may be in the form of neutral or basic metal salts. Antioxidant additives are in particular sterically hindered phenols, esters of sterically hindered phenols, and sterically hindered phenols containing thioether bridges, diphenylamines, at least one C1-C 12 diphenylamines substituted with an alkyl moiety, N,N'-dialkylaryldiamines, and mixtures thereof. Preferentially, the sterically hindered phenol is selected from compounds containing a phenol moiety in which at least one carbon adjacent to the carbon atom having an alcohol functional group is substituted by at least one C1-C 10 alkyl moiety, preferentially a C1-C6 alkyl moiety, preferentially a C4 alkyl moiety, preferentially a tert-butyl moiety. Amine compounds are another class of antioxidant additives that can optionally be used in combination with phenolic antioxidant additives. Examples of amine compounds are aromatic amines, such as the formula NR 5 R 6 R 7 (wherein R 5 represents an aliphatic moiety or an optionally substituted aromatic moiety, R 6 represents an optionally substituted aromatic moiety, R 7 represents a hydrogen atom, an alkyl moiety, an aryl moiety or the formula R 8 S(O) z R 9represents a moiety having, where R 8 represents an alkylene or alkenylene moiety, and R 9 represents an alkyl moiety, an alkenyl moiety or an aryl moiety, and z is 0, 1 or 2). The aromatic amine is used. Sulfurized alkylphenol, or its alkali or alkaline earth metal salt can also be further used as an antioxidant additive.

[0100] Advantageously, the lubricating composition contains at least one antioxidant additive that does not contain ash.

[0101] The additive can be used in the lubricating composition according to the present invention at a ratio of 0.1 to 2% by weight based on the total mass of the composition.

[0102] The lubricating composition according to the present invention can contain at least one antiwear additive, one extreme pressure additive, or a mixture thereof.

[0103] The antiwear additive and the extreme pressure additive protect the surface exposed to friction by forming a protective film adsorbed on the surface.

[0104] There are a wide variety of antiwear additives. Preferably, the antiwear additive is selected from metal alkylthiophosphates, more particularly zinc alkylthiophosphates, more particularly zinc dialkyldithiophosphates or phosphorus-sulfur based additives such as ZnDTP. A preferred compound has the formula Zn((SP(S)(OQ 2 )(OQ 3 ))2, where Q 2 and Q 3 are either the same or different and independently represent an alkyl moiety, preferably an alkyl moiety containing 1 to 18 carbon atoms.

[0105] Preferably, the lubricating composition according to the present invention has the formula

Chemical formula

[0106] Amine phosphates are also antiwear additives that can be used in the lubricating compositions according to the present invention. However, the phosphorus provided by such additives forms ash and can potentially act as a poison in automotive catalyst systems. Such effects can be minimized by partially replacing amine phosphates with additives that do not provide phosphorus, such as polysulfides, especially sulfur olefins.

[0107] The lubricating composition may contain, based on the total weight of the composition, 0.01 to 6% by weight, preferably 0.05 to 4% by weight, more preferably still or 0.1 to 2% by weight of antiwear additives and extreme pressure additives.

[0108] The lubricating composition according to the present invention can further contain at least one defoaming agent.

[0109] The defoaming agent can be selected from silicones.

[0110] The lubricating composition can contain, based on the total weight of the fluid, 0.01 to 2% by weight or 0.01 to 5% by weight, preferably 0.1 to 1.5% by weight or 0.1 to 2% by weight of the defoaming agent.

[0111] The lubricating composition according to the present invention can further contain at least one friction modifier additive.

[0112] Friction adjustment additives function to limit friction by forming an adsorbed monolayer on the surface of the metal with which they come into contact. This can be selected from compounds that provide metal elements and ashless compounds. Examples of compounds that provide metal elements include transition metal complexes such as Mo and Sb. Sn, Fe, Cu, Zn, where the ligand can be a hydrocarbon compound containing oxygen, nitrogen, sulfur or phosphorus atoms. Ashless friction adjustment additives are generally of organic origin and can be selected from esters of fatty acids and polyols, alkoxylated amines, alkoxylated fatty amines, fatty epoxides, fatty epoxide borates, amino acids or fatty acid glycerol esters, which are different from the monoesters required according to the present invention. According to the present invention, the fatty compound contains at least one hydrocarbon moiety containing 10 to 24 carbon atoms. More specifically, the molybdenum compound may be selected from molybdenum dithiocarbamate (Mo-DTC), molybdenum dithiophosphate (Mo-DTP), and mixtures thereof. The lubricating composition may particularly contain a molybdenum content of 1000 to 2500 ppm.

[0113] The lubricating composition may contain 0.01 to 5% by weight, more specifically 0.1 to 2% by weight, or even more specifically 0.1 to 1.5% by weight of the friction adjustment additive based on the total mass of the composition.

[0114] When used at too high a content, the molybdenum compound may have an adverse effect on the low-temperature properties of the lubricating composition used. Thereby, the lubricating composition according to the present invention preferably contains less than 1.5% by weight, more preferably less than 1% by weight, or even no molybdenum based on the total weight of the composition.

[0115] The lubricating composition according to the present invention can contain at least one detergent additive.

[0116] Detergent additives generally reduce the formation of deposits on the surface of metal parts by dissolving oxidation and combustion by-products.

[0117] Detergent additives that can be used in lubricating compositions are generally known to those skilled in the art. The detergent additive can be an anionic compound containing a lipophilic hydrocarbon moiety and a hydrophilic head. The associated cation can be a metal cation of an alkali metal or an alkaline earth metal.

[0118] The detergent additive is preferably selected from alkali metal salts or alkaline earth metal salts of carboxylic acids, sulfonates, salicylates, naphthenates, and phenates. The alkali metals and alkaline earth metals are preferably calcium, magnesium, sodium or barium.

[0119] Such metal salts generally contain the metal in stoichiometric or excess amounts, i.e., at a concentration higher than the stoichiometric amount. At this time, these are overbased detergents, and the excess metal that gives the overbased characteristic to the detergent additive is generally in the form of an oil-insoluble metal salt, such as a carbonate, hydroxide, oxalate, acetate, glutamate, preferably a carbonate.

[0120] The lubricating composition can contain, for example, 2 to 4% by weight of the detergent additive based on the total weight of the composition.

[0121] The lubricating composition used according to the present invention can further contain at least one pour point depressant (PPD) additive.

[0122] By retarding the formation of paraffin crystals, the pour point depressant generally improves the behavior of the composition under low temperature conditions. Examples of pour point depressants include alkyl polymethacrylates, polyacrylates, polyaryl amides, polyalkyl phenols, polyalkyl naphthalenes, and alkyl polystyrenes.

[0123] The lubricating composition according to the present invention can contain, in particular, 0.1% to 2%, preferably 0.2% to 1% of the pour point depressant based on the total weight of the composition.

[0124] In addition, the lubricating composition can contain at least one dispersant.

[0125] The dispersant can be selected from Mannich bases, succinimides and their derivatives, such as derivatives of polyisobutylene succinic anhydride.

[0126] For example, the lubricating composition can contain 0.2 to 10% by weight of the dispersant based on the total weight of the composition.

[0127] The lubricating composition used according to the present invention can contain at least one viscosity index (VI) improver additive.

[0128] Viscosity index improvers, more particularly polymers that improve the viscosity index, provide good cold resistance and minimum viscosity at high temperatures.

[0129] Examples of polymers that improve the viscosity index include polymer esters, hydrogenated or non-hydrogenated homopolymers or copolymers of styrene, butadiene and isoprene, homopolymers or copolymers of olefins such as ethylene or propylene, polyacrylates and polymethacrylates (PMA), preferably homopolymers or copolymers of olefins such as ethylene or propylene.

[0130] More particularly, the lubricating composition according to the present invention may contain 1% to 15% by weight, preferably 5% to 10% by weight, of an additive that improves the viscosity index based on the total weight of the lubricating composition.

[0131] The lubricating composition may also contain at least one defoaming additive selected from polar polymers such as polymethylsiloxane or polyacrylate.

[0132] More particularly, the lubricating composition according to the present invention can contain 0.01% to 3% by weight of the additive based on the total weight of the lubricating composition.

[0133] The lubricating composition may also contain at least one anticorrosive agent or copper passivator, such as compounds like polyisobutene succinic anhydride, thiadiazole sulfonate, or mercaptobenzothiazole. These are typically present in the lubricating composition according to the invention in a content of 0.01% to 1% by weight based on the total weight of the composition.

[0134] Advantageously, the lubricating composition according to the invention contains one or more additives selected from viscosity index improvers, pour point depressants, antiwear agents, and antioxidants.

[0135] According to a particular embodiment, the lubricating composition according to the invention comprises (i) at least one diester according to the invention, and (ii) at least one additive selected preferably from antioxidants, viscosity index improvers, pour point depressants, antiwear and / or extreme pressure additives, antifoaming agents, detergents, dispersants, and mixtures thereof, more preferably from antioxidants, viscosity index improvers, pour point depressants, antiwear and extreme pressure additives, and mixtures thereof, or is even formed by these.

[0136] Advantageously, the lubricating composition according to the invention is formed by (i) at least one diester corresponding to one of formulas (I), (II), or (III) as defined above, and (ii) at least one antioxidant additive.

[0137] Advantageously, the lubricating composition according to the invention is formed by (i) at least one diester corresponding to one of formulas (I) or (II) as defined above, and (ii) at least one antioxidant additive.

[0138] According to a particular embodiment, the composition according to the invention - at least 5% by weight, preferably at least 10% by weight, preferably at least 30% by weight, preferably at least 50% by weight, more preferably at least 70% by weight, or even at least 90% by weight of a diester corresponding to one of formulas (I), (II), or (III), and - 0.01 to 20% by weight, preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, or more preferably still 0.5 to 7% by weight, or even 1 to 5% by weight, of one or more additives selected from friction modifiers, antiwear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, antifoaming agents, thickeners, corrosion inhibitors, copper thickeners and mixtures thereof, - Optionally, 5 to 94% by weight, preferably 10 to 94% by weight, preferably 15 to 90% by weight of a base oil different from the diester according to the present invention comprising, or even consisting of, these The content is expressed relative to the total weight of the composition.

[0139] According to a particular embodiment, the composition according to the present invention relative to the total weight of the composition - 5 to 95% by weight, preferably 10 to 90% by weight, more preferably 20 to 80% by weight, even more preferably 30 to 70% by weight, or even 40 to 60% by weight, of a diester corresponding to one of formula (I), (II) or (III), - 5 to 95% by weight, preferably 10 to 90% by weight, more preferably 20 to 80% by weight, or more preferably still 30 to 70% by weight, or even 40 to 60% by weight, of one or more base oils different from the said diester, - Optionally, 0.01 to 20% by weight, preferably 0.05 to 15% by weight, or preferably 0.1 to 10% by weight, even more preferably 0.5 to 7% by weight, or even 1 to 5% by weight, of one or more additives different from the diester and different from the base oil comprising, or even consisting of, these The content is expressed relative to the total weight of the composition.

[0140] According to a particular embodiment, the lubricating composition according to the present invention - At least 5% by weight, preferably 10% to 40% by weight, more preferably 15% to 30% by weight, of one or more diesters according to the invention, defined above and preferably corresponding to formula (I), selected from the diesters - 50% to 95% by weight of a base oil different from the diester defined according to the invention, preferably a base oil selected from Group II and / or Group III base oils according to the API classification - Optionally, 5% to 15% by weight of at least one viscosity index improver - Optionally, 0.1% to 1% by weight of at least one pour point depressant additive - Optionally, 0.01% to 6% by weight of at least one antiwear additive, and - Optionally, 0.1% to 2% by weight of at least one antioxidant additive comprising, or even consisting of, these The contents are expressed relative to the total weight of the composition.

[0141] Preferably, the lubricating composition according to the invention - Less than 30% by weight, more particularly 1% to 30% by weight, especially 5% to 30% by weight, preferably 10% to 30% by weight, more particularly 15% to 30% by weight, of one or more diesters according to the invention, defined above and preferably selected from the diesters of formula (I) or (II) - 50% to 85% by weight of a base oil different from the diester defined according to the invention, preferably a base oil selected from Group II and / or Group III base oils according to the API classification - Optionally, 5% to 15% by weight of at least one viscosity index improver - Optionally, 0.1% to 1% by weight of at least one pour point depressant additive - Optionally, 0.01% to 6% by weight of at least one antiwear additive, and - Optionally, 0.1% to 2% by weight of at least one antioxidant additive comprising, or even consisting of, these The content is expressed based on the total weight of the composition.

[0142] According to certain embodiments, the composition according to the present invention - 5 to 95% by weight, preferably 5 to 50% by weight, or preferably 10 to 40% by weight of said diester corresponding to formula (I) or (II), and - 5 to 95% by weight, preferably 50 to 95% by weight, preferably 60 to 90% by weight of one or more different said diesters, and - Optionally, 0.01 to 20% by weight, preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, or more preferably 0.5 to 7% by weight, or even 1 to 5% by weight of one or more additives selected from friction modifier additives, antiwear additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressant additives (PPD), dispersants, antifoaming agents, thickeners, corrosion inhibitors, copper passivators and mixtures thereof contain, or even consist of these, The content is expressed based on the total weight of the composition.

[0143] The composition according to the present invention advantageously has a kinematic viscosity in the range of 1 to 20 mm 2 / s, preferably 2 to 15 mm 2 / s, measured at 100 °C according to the ASTM D445 standard.

[0144] The composition according to the present invention advantageously has a kinematic viscosity in the range of 20 to 50 mm 2 / s, preferably 25 to 40 mm 2 / s, measured at 40 °C according to the ASTM D445 standard.

[0145] The composition according to the present invention has good lubricating properties.

[0146] The composition according to the present invention also has good properties in terms of cold resistance.

[0147] The composition according to the present invention also has good cooling properties.

[0148] A further subject of the present invention is the use of diesters in a composition for lubricating and / or cooling at least one component of a mobile or stationary system, wherein said diesters are - selected from diols selected from 1,2-propanediol, 1,2-decanediol and 1,3-diols having from 3 to 10 carbon atoms, - with the same or different monocarboxylic acids having a straight-chain or branched hydrocarbon chain having from 4 to 10 carbon atoms and are formed therebetween, preferably, the composition for lubricating and / or cooling further comprises at least one base oil different from the diester and / or at least one additive different from the diester, and said additive is selected from antioxidants, pour point depressants, antifoaming agents, corrosion inhibitors, antiwear and / or extreme pressure additives, friction modifiers, detergents, dispersants, and mixtures thereof, more particularly selected from antioxidants, pour point depressants, antifoaming agents, and corrosion inhibitors, relating to use.

[0149] One or more features of the diesters presented in the context of the composition according to the invention also apply to the diesters used according to the invention.

[0150] According to one embodiment of the use according to the invention, the component to be lubricated and / or cooled is a component of a heavy or light vehicle, a utility machine, or an energy storage device (e.g., a data center).

[0151] The diesters defined in the present invention help to reduce the friction coefficient of lubricating compositions.

[0152] The diesters defined in the present invention make it possible to cool elements of mobile or stationary systems such as heavy or light vehicles, utility machines, energy storage devices.

[0153] According to the present invention, more particularly, the composition formulated as described above has excellent tribological properties, particularly with regard to friction reduction, and is thus particularly well - suited for use as a lubricating fluid.

[0154] According to the present invention, more particularly, the composition formulated as described above has excellent thermal properties, particularly with regard to thermal conductivity, and is thus particularly well - suited for use as a cooling fluid.

[0155] The composition of the present invention is suitable for lubricating automotive transmission components, particularly transmissions for light or heavy vehicles, such as gearboxes and / or axles.

[0156] More particularly, it can be used to lubricate the manual gearbox and / or axle of a light or heavy vehicle. Advantageously, the lubricating composition according to the present invention has performance, more particularly performance regarding low - temperature characteristics, which is particularly well - suited for use in lubricating the transmission of heavy vehicles, more particularly for lubricating the manual gearbox and / or the axle of a heavy vehicle.

[0157] The present invention further relates to a method for lubricating and / or cooling a part, comprising bringing the composition according to the present invention into contact with at least a part of a movable or fixed system.

[0158] According to one embodiment, the movable or fixed system is selected from heavy or light vehicles, utility machines, energy storage devices such as data centers.

[0159] The present invention further relates to a method for lubricating and / or cooling at least one mechanical part, particularly an automotive transmission member, comprising bringing the lubricating composition according to the present invention into contact with the mechanical part, more particularly the automotive transmission part.

[0160] The diesters defined in the present invention can be added to lubricating compositions used in vehicle transmissions in order to improve the "fuel consumption" characteristics of the lubricating composition, i.e., the ability to limit the fuel consumption of motor vehicles, without affecting their performance, particularly with respect to low-temperature characteristics.

[0161] Here, the present invention will be described by the following examples, which are given by way of illustration of the invention and are not intended to be limiting.

[0162] Example Example 1: Preparation of Compounds to be Tested The following compounds were prepared: - Diester A: A diester formed from 1,2-decanediol and two heptanoic acids - Diester B: A diester formed from 1,2-decanediol and two pentanoic acids - Diester C: A diester formed from 1,2-propanediol and two heptanoic acids - Diester D: A diester formed from 1,2-propanediol and two nonanoic acids - Diester E: A diester formed from 1,3-propanediol and two heptanoic acids - Diester F: A mixture of diesters formed from 1,2-propanediol and a cut of biological C8 - C10 acids - A monoester formed from a monocarboxylic acid having a saturated hydrocarbon chain of 3 to 14 carbon atoms and a monoalcohol having a saturated hydrocarbon chain of 3 to 14 carbon atoms.

[0163] The diesters and monoesters were prepared according to known ester preparation methods.

[0164] The compositions to be tested below in the examples contain 100% of each ester (diester or monoester) defined in Example 1.

[0165] Example 2: Viscosity Measurement The kinematic viscosities at 100 °C (KV100) and 40 °C (KV40) were determined in accordance with ASTM D445 standard.

[0166] The viscosities are shown in Table 2.

Table 2

[0167] All the diesters used according to the present invention have a viscosity of less than 4 mm 2 / s at 100 °C.

[0168] Example 3: Measurement of Coefficient of Friction Tribological properties can be evaluated by tests on a ball-disk rotational tribometer (also called ball-on-plane type) such as a reciprocating linear tribometer. This test helps to evaluate the performance of lubricants regarding friction under mixed / limited conditions according to the applied load, pressure or speed conditions.

[0169] The coefficient of friction of the lubricating composition to be tested is determined at 40 °C by using a hardened steel ball with a diameter of about 2 cm, for example 1.905 cm, on a hardened steel plane.

[0170] The tribometer can be a device that moves a steel ball and a steel plane relative to each other to determine the friction / coefficient of friction of a given lubricating composition while varying various characteristics such as speed, load, and temperature. The hardened steel surface has an AISI 52100 standard by mirror finish, and the ball also has an AISI 52100 standard and is made of hardened steel.

[0171] The applied load is 25 N, and the driving speed varies from 10 mm / s to 2500 mm / s respectively. More specifically, the coefficient of friction is determined at a rotational speed of 10 mm / s. The coefficient is determined at a 5% slip-to-rotation ratio (%SRR).

[0172] Approximately 50 ml of the lubricating composition to be tested was added to the device. The ball was fitted to face the plane, and the ball and the plane were moved independently to produce a mixed rotation / sliding contact.

[0173] The coefficient of friction is measured and recorded by a force sensor.

[0174] Driving speed 225 mm 2 The results at / s are shown in Table 3.

[0175] The lubricating compositions tested contain each ester defined in Example 1 at 100%.

Table 3

[0176] The results show that the diesters used according to the present invention have a very low coefficient of friction, more specifically lower than that of the monoesters.

[0177] Example 4: Measurement of flash point in small quantities The flash point in small quantities is measured according to the ASTM D93Ac standard (Cleveland open cup method).

[0178] The values are shown in Table 4.

Table 4

[0179] As shown by the values in Table 4, the flash point is even better when the diester is a branched-chain diester. In fact, the diester formed from 1,2-propanediol has a lower flash point than the diester formed from 1,3-propanediol having the same total number of carbon atoms.

[0180] Example 5: Measurement of pour point in small quantities The pour point in small quantities is measured according to the ASTM D7346 standard.

[0181] The values are shown in Table 5.

Table 5

[0182] The results in Table 5 show that the diesters used in the lubricating composition according to the present invention have a low pour point, more specifically a lower pour point than the monoester.

[0183] Example 6: Measurement of traction coefficient The traction coefficient (COT) was measured using a PCS Instrument MTM tribometer. This helps to evaluate the performance of lubricants with respect to friction under mixed / hydrodynamic conditions. The test consists of moving a steel ball and a steel plane relative to each other at different speeds, making it possible to define the %SSR (sliding to rotation ratio) corresponding to the sliding speed / driving speed.

[0184] The measurement conditions were a load of 25 N, a disk speed of 1.4 m / s, and an SRR of 20% at an estimated temperature of 100 °C.

[0185] The lower the traction coefficient of the lubricating composition, the lower the friction between metal parts and the better the fuel efficiency.

[0186] The results obtained are shown in Table 6. [Table 6]

[0187] The results show that the diesters used according to the present invention have a very low traction coefficient, more specifically a lower traction coefficient than the monoester.

[0188] Example 7: Measurement of thermal conductivity The thermal conductivity of the compound described in Example 1 was measured at different temperatures according to the ASTM D7896-19 standard.

[0189] The results are shown in Table 7. [Table 7]

[0190] The results indicate that the diesters defined in the present invention have good thermal properties, thereby enabling their use as cooling fluids.

Claims

1. - One or more diesters, each of the diesters is A diol selected from o1,2-propanediol, 1,2-decanediol, and 1,3-diol having 3 to 10 carbon atoms, o Having a linear or branched hydrocarbon chain having 4 to 10 carbon atoms, wherein the hydrocarbon chain is optionally interrupted by one or more heteroatoms, and two identical or different monocarboxylic acids A diester is formed between them, - At least one base oil different from the diester and / or at least one additive different from the diester, wherein the additive is selected from friction modifiers, wear-resistant additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, defoamers, thickeners, corrosion inhibitors, copper passivators and mixtures thereof, and A lubricating composition containing the following:

2. The lubricating composition according to claim 1, wherein the linear or branched hydrocarbon chain having 4 to 10 carbon atoms is a linear or branched, saturated or unsaturated alkyl chain or alkylene chain consisting of carbon atoms and hydrogen atoms.

3. With respect to the total weight of the aforementioned composition, - 5 to 95% by weight, preferably 10 to 90% by weight, otherwise preferably 20 to 80% by weight, otherwise more preferably 30 to 70% by weight, or even more preferably 40 to 60% by weight of one or more of the diesters, -1 to 95% by weight, preferably 10 to 90% by weight, more preferably 20 to 80% by weight, otherwise more preferably 30 to 70% by weight, or even more preferably 40 to 60% by weight, one or more base oils different from the diester, -Optionally, 0.01 to 20% by weight, preferably 0.05 to 15% by weight, otherwise preferably 0.1 to 10% by weight, otherwise more preferably 0.5 to 7% by weight, or even more preferably 1 to 5% by weight, one or more additives different from the diester and different from the base oil. A lubricating composition according to claim 1 or 2, comprising:

4. With respect to the total weight of the aforementioned composition, - One or more diesters in an amount of at least 5% by weight, preferably at least 10% by weight, preferably at least 30% by weight, preferably at least 50% by weight, more preferably at least 70% by weight, or even more preferably at least 90% by weight, - 0.01 to 20% by weight, preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, otherwise more preferably 0.5 to 7% by weight, or even more preferably 1 to 5% by weight, one or more additives selected from friction modifiers, wear-resistant additives, extreme pressure additives, cleaning agents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPDs), dispersants, defoamers, thickeners, copper thickeners, corrosion inhibitors and mixtures thereof, - Where appropriate, 5 to 94% by weight, preferably 10 to 94% by weight, preferably 15 to 90% by weight, of a base oil different from the diester according to the present invention. A lubricating composition according to claim 1 or 2, comprising:

5. The lubricating composition according to claim 1 or 2, wherein the diester has 13 to 25 carbon atoms, preferably 13 to 24 carbon atoms.

6. The aforementioned diester is 1 to 6 mm at 100°C. ２ Within the range of / s, preferably 1 to 4 mm ２ The lubricating composition according to claim 1 or 2, having a kinematic viscosity in the range of / s.

7. The lubricating composition according to claim 1 or 2, wherein the diol is preferably selected from 1,2-propanediol and 1,3-propanediol, which have 3 to 7 carbon atoms, and otherwise preferably the diol is 1,2-propanediol.

8. The lubricating composition according to claim 1 or 2, wherein the monocarboxylic acid is either the same or different and comprises a straight-chain hydrocarbon chain having 4 to 10 carbon atoms, preferably 5 to 9 carbon atoms.

9. - The diester is, - A diol selected from 1,2-decanediol and 1,3-propanediol, - Having a linear or branched hydrocarbon chain having 4 to 10 carbon atoms, wherein the hydrocarbon chain is optionally interrupted by one or more heteroatoms, and two identical or different monocarboxylic acids Diesters formed between them, A diester formed from -1,2-propanediol and two heptanoic acids, A diester formed from -1,2-propanediol and two octanoic acids, A diester formed from -1,2-propanediol and two decanoic acids, A diester formed from -1,2-propanediol, octanoic acid, and decanoic acid, - and mixtures thereof A lubricating composition according to claim 1 or 2, selected from the above.

10. The aforementioned diester, A diester formed from -1,2-decanediol and two heptanoic acids, A diester formed from -1,2-decanediol and two pentanoic acids, A diester formed from -1,2-propanediol and two heptanoic acids, A diester formed from -1,2-propanediol and two nonanoic acids, A diester formed from -1,3-propanediol and two heptanoic acids, A diester formed from -1,2-propanediol and two octanoic acids, A diester formed from -1,2-propanediol and two decanoic acids, A diester formed from -1,2-propanediol, octanoic acid, and decanoic acid, - and mixtures thereof A lubricating composition according to claim 1 or 2, selected from the above.

11. The use of at least one diester in a lubricating composition, The aforementioned diester, A diol selected from -1,2-propanediol, 1,2-decanediol, and 1,3-diol having 3 to 10 carbon atoms, -Having a linear or branched hydrocarbon chain having 4 to 10 carbon atoms, wherein the hydrocarbon chain is optionally interrupted by one or more heteroatoms, and two identical or different monocarboxylic acids It is formed between, The lubricating composition comprises at least one base oil different from the diester and / or at least one additive different from the diester, wherein the additive further comprises at least one base oil and / or at least one additive selected from friction modifiers, wear-resistant additives, extreme pressure additives, detergents, antioxidants, viscosity index (VI) improvers, pour point depressants (PPD), dispersants, defoamers, thickeners, corrosion inhibitors, copper passivators and mixtures thereof. use.

12. For example, the use according to claim 11 for lubricating and / or cooling at least one element of a moving system or a stationary system, selected from heavy or light vehicles, public works vehicles, and energy storage systems.

13. The use according to claim 12, wherein the moving system is a vehicle, and the lubricating composition is used to reduce the fuel consumption of a vehicle equipped with transmission components lubricated by the composition, particularly the fuel consumption of the gearbox and / or axles.

14. The use according to any one of claims 11 to 13, wherein the diester is as defined in claim 2, and / or the lubricating composition is as defined in claim 3.