Lubricating fluid composition comprising 6-undecanol di and tri-esters for use as gear oil formulation

Abstract

The invention relates to lubricating fluid compositions comprising some specific 6-undecanol di- and tri-esters and which are intended for use as driveline fluids and heat transfer fluids The invention is also directed to a method for preparing the aforesaid lubricating fluid compositions, as well as to a method of improving efficiency of gear box and / or electric devices by using the lubricating fluid compositions according to the invention.

Description

[0001] 202400078 Foreign Filing 1

[0002] Lubricating fluid composition comprising 6-undecanol di and tri-esters for use as gear oil formulation

[0003] TECHNICAL FIELD OF THE INVENTION

[0004] The invention relates to lubricating fluid compositions comprising some specific 6-undecanol di- and triesters and which are intended for use as driveline fluids and heat transfer fluids. The invention is also directed to a method for preparing the aforesaid lubricating fluid compositions, as well as to a method of improving efficiency of gear box and / or electric devices by using the lubricating fluid compositions according to the invention.

[0005] BACKGROUND OF THE INVENTION

[0006] Only about 15% to 30% of the energy from the fuel added in a conventional vehicle is used to move it down the road, depending on the drive cycle. The rest of the energy is lost to engine and driveline inefficiencies or used to power accessories. Therefore, the potential to improve fuel efficiency with advanced technologies is enormous.

[0007] JP2017160366 discloses a gear oil composition which contains a base oil having a kinematic viscosity at 100 °C of 4.5-6.5 mm2 / s; 0.5-2.0 mass% of an SP-based additive containing an alkylphosphorothioate compound and a hydrocarbylamine compound; 1 ,000-4,000 mass ppm of a calcium-based detergent as a calcium agent; and a triazole derivative, wherein the base oil may contain from 0 to 40 mass% of an ester oil, based on the total amount of the base oil. The amount of ester in the gear oil composition is thus optional. Furthermore, the kinematic viscosity of the gear oil composition at 40 °C is 40 mm2 / s or less, and a viscosity index is 140 or more. The document is silent on the importance of ester structure characteristic to the fluid performance.

[0008] There is still a need to find improved driveline fluid formulations having a low friction and kinematic viscosity, even at low temperature, while maintaining a high flashpoint and shear stability. Specifically, the driveline fluid composition should be much easier to formulate thanks to a much lower viscosity from a low to high temperature range, while still keeping a high flash point without any concern.

[0009] BRIEF SUMMARY OF THE INVENTION

[0010] After a thorough investigation, the inventors of the present invention have surprisingly found that a lubricating fluid composition comprising the specific di- and tri-esters of Formula (I) and (II) as defined below show excellent performance properties as a driveline fluid. In particular, the lubricating fluid composition according to the present invention can be useful for all kinds of lubricant formulations which require low viscosity, even at low temperatures, while keeping a high flash point. It is thus possible to formulate in a easier manner much lower viscosity gear oil fluids while keeping a high flash point without any concern, which provides more flexibility for the end-user formulation development. 202400078 Foreign Filing 2

[0011] According to a first aspect, the invention relates to a lubricating fluid composition comprising the di- and triesters of Formula (I) and (II), respectively, as defined in claim 1 and its dependent claims.

[0012] According to a second aspect, the invention relates to the use of the lubricating fluid composition or the ester A) according to the present invention in a heat transfer fluid.

[0013] A third aspect of the invention is the use of the lubricating fluid composition or the ester A) according to the present invention to improve efficiency of gear box in a mechanical device which uses a gear set to change the speed or direction of rotation. The gear box of the mechanical device is preferably the gearbox or pump of an automobile, a wind turbine, or a hydraulic system.

[0014] A fourth aspect of the invention is a method of reducing friction between two or more metal parts of a device such as an engine, a gearbox or pump of an automobile, a wind turbine, or a hydraulic system, the method comprising using the lubricating fluid composition or the ester A) according to the invention in said devices.

[0015] According to another aspect, the invention relates to a method of enhancing the heat transfer in a battery system or an electrical equipment system, the method comprising using the lubricating fluid composition according to the invention in the battery system or the electrical equipment system.

[0016] According to another aspect of the present invention, the present invention also relates to a method of lowering the pour point of a lubricating fluid composition by adding the ester A) according to the invention, to said composition.

[0017] DETAILED DESCRIPTION OF THE INVENTION

[0018] Lubricating fluid compositions according to the invention

[0019] The present invention relates to a lubricating fluid composition comprising:

[0020] A) an ester selected from the group consisting of di(undecane-6-yl) dicarboxylate A1) of Formula (I), tri(undecane-6-yl) tricarboxylate A2) of Formula (II), or a mixture thereof,

[0021] Formula (I) wherein Ri is selected from a linear or branched alkylene group having from 4 to 9 carbon atoms, 202400078 Foreign Filing 3

[0022] Formula (II) wherein R2 is selected from a hydrocarbon group having from 1 to 3 carbon atoms,

[0023] B) a viscosity index improver selected from the group consisting of a polyalkyl (meth)acrylate B1) prepared by polymerizing a monomer composition comprising branched C7-C15 alkyl (meth)acrylate monomer, a polyalkyl (meth)acrylate B2) prepared by polymerizing a monomer composition comprising polybutadiene-based monomers, an acrylate-olefin copolymer B3), a polyalphaolefin B4), or a mixture thereof, and

[0024] C) a pour point depressant polymer which is a polyalkyl (meth)acrylate prepared by polymerizing a monomer composition consisting of a mixture of linear C7-C15 alkyl(meth)acrylates and linear and / or branched C16-C30 alkyl(meth)acrylates and optionally linear Ci-Ce alkyl(meth)acrylates.

[0025] In the context of the present invention, the term “6-undecanol ester A1)” or “6-undecanol ester A2)” means the 6-undecanol esters of the invention, namely, di(undecane-6-yl) dicarboxylate A1) of Formula (I) or tri(undecane-6-yl) tricarboxylate A2) of Formula (II), respectively.

[0026] Preferably, R1 in Formula (I) is a linear alkylene group having from 4 to 9 carbon atoms, more preferably a linear alkylene group having from 4 to 8 carbon atoms.

[0027] Preferably, the lubricating fluid composition comprises from 5 to 80 % by weight, preferably from 8 to 75 % by weight, more preferably from 10 to 70 % by weight, of di(undecane-6-yl) dicarboxylate A1), tri(undecane- 6-yl) tricarboxylate A2) or a mixture thereof, based on the total weight of the lubricating fluid composition.

[0028] According to another preferred aspect of the invention, the lubricating fluid composition comprises from 5 to 60 % by weight, preferably from 8 to 50 % by weight, more preferably from 10 to 45 % by weight, of the viscosity index improver B), based on the total weight of the lubricating fluid composition.

[0029] Preferably, the lubricating fluid composition comprises from 0.1 to 5 % by weight, preferably from 0.1 to 3 % by weight, more preferably from 0.1 to 2 % by weight, of the pour point depressant C), based on the total weight of the lubricating fluid composition. 202400078 Foreign Filing 4

[0030] As shown in the experimental part below, the lubricating fluid compositions of the present invention have low viscosity in low to high temperature range while keeping high flash point properties without any concern. A further advantage of the lubricating fluid compositions according to the invention is their low viscosity, which allows an improvement of the efficiency of gear box and / or electric devices.

[0031] According to a preferred aspect of the invention, the lubricating fluid composition has a friction coefficient less than 0.030 at 0.8 m / s, tested by Mini traction machine, and a slide-roll ratio with Ball on Disk at 80 °C under 35N of 50 %. Due to the friction coefficient less than 0.030 exhibited by the lubricating fluid composition, a lubricating fluid composition with a low coefficient friction can be obtained (see details on method of measurement in experimental part).

[0032] According to a preferred aspect of the invention, the lubricating fluid composition has a friction coefficient lower than 5% compared to standard-friction formulation without the inventive ester, tested by Mini traction machine at 0.8 m / s, and a slide-roll ratio with Ball on Disk at 80 °C under 35N of 50 % (see details on method of measurement in experimental part).

[0033] Preferably, the total amount of all components in the lubricating fluid composition (namely, ester A), viscosity index improver B), pour point depressant C) and optionally base oil D) and / or additives E), sum up to 90 % by weight or more, more preferably sum up to 95 % by weight or more, even more preferably ranges from 95 to 99 % by weight, most preferably sum up to 100 % by weight, based on the total weight of the lubricating fluid composition.

[0034] All characteristics and preferences indicated below for each component of the lubricating fluid composition apply to the lubricating fluid composition.

[0035] Esters A)

[0036] As indicated above, the ester A) according to the present invention is selected from the group consisting of di(undecane-6-yl) dicarboxylate A1) of Formula (I), tri(undecane-6-yl) tricarboxylate A2) of Formula (II), or a mixture thereof.

[0037] According to a preferred aspect of the invention, the di(undecane-6-yl) dicarboxylate A1) of Formula (I) or the tri(undecane-6-yl) tricarboxylate A2) is the product of the esterification reaction of 6-undecanol with an acid, and the chemical structure of the 6-undecanol di- and tri-ester A1) or A2) depends on the structure of the acid reactant. For example, the esters of the present invention can be prepared by the esterification as described in EP2155754.

[0038] According to another preferred aspect of the invention, the di(undecane-6-yl) dicarboxylate A1) of Formula (I) or the tri(undecane-6-yl) tricarboxylate A2) is the product of a transesterification reaction of dimethyl di carboxy I ate, diethyl dicarboxylate, trimethyl tricarboxylate, or triethyl tricarboxylate. The chemical 202400078 Foreign Filing 5 structure of the di(undecane-6-yl) dicarboxylate A1) or tri(undecane-6-yl) tricarboxylate A2) depends on the structure of the reactant carboxylic acid moiety.

[0039] Preferably, when the di(undecane-6-yl) dicarboxylate A1) or tri(undecane-6-yl) tricarboxylate A2) is obtained by reacting with two or more acids, then the resulting ester is a mixture of 6-undecanol di- and / or tri-esters obtained by reacting 6-undecanol with each of these acids.

[0040] According to a preferred aspect of the invention, the acid moiety which reacts with 6-undecanol to prepare the di(undecane-6-yl) dicarboxylate A1) of Formula (I) is preferably selected from a group consisting of adipic acid, 2,2-dimethylpentanedioic acid, 3,3-dimethylglutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dipropyl malonic acid, 3-ethyl-3-methylglutaric acid, trimethyl adipic acid, or a mixture thereof. Most preferred acids are adipic acid, azelaic acid, sebacic acid, or a mixture thereof.

[0041] According to another preferred aspect of the invention, the acid moiety which reacts with 6-undecanol to prepare the tri(undecane-6-yl) tricarboxylate A2) of Formula (II) is preferably selected from the group consisting of tricarballylic acid, carboxymalonic acid or a mixture thereof. Most preferred acid to 6- undecanol diester A2) is carboxymalonic acid.

[0042] According to a preferred aspect of the invention, the ester A) is selected from the group consisting of di(undecyl-6-yl)adipate, di(undecyl-6-yl)2,2-dimethylpentanedioate, di(undecyl-6-yl)3,3- dimethypentanedioate, di(undecyl-6-yl)heptanedioate, di(undecyl-6-yl)octanedioate, di(undecyl-6-yl)2,2- dipropyl malonate, di(undecan-6-yl)3-ethyl-3-methylpentanedioate, di(undecyl-6-yl) trimethyl adipate, tri(undecan-6-yl) methanetricarboxylate, tri(undecan-6-yl) propane-1 ,2, 3-tricarboxylate, di(undecyl-6- yl)nonanedioate, and di(undecyl-6-yl)decanedioate, or a mixture thereof. More preferably, the ester A) is selected from the group consisting of di(undecyl-6-yl)adipate, di(undecyl-6-yl)nonanedioate, di(undecyl-6- yl)decanedioate, or a mixture thereof.

[0043] Preferably, the di(undecane-6-yl) dicarboxylate A1) of Formula (I) or the tri(undecane-6-yl) tricarboxylate A2) of Formula (II) has a kinematic viscosity at 100°C of 2.0 to 7.0 mm2 / s, more preferably of 3.0 to 6.0 mm2 / s even more preferably from 3.3 to 4.7 mm2 / s, as determined by ASTM D7042. Thanks to the low kinematic viscosity at 100°C exhibited by these 6-undecanol esters A), low viscosity in high temperature range can be also imparted to a lubricating fluid composition comprising the di(undecane-6-yl) dicarboxylate A1), tri(undecane-6-yl) tricarboxylate A2) or a mixture thereof, which is for example advantageous for enhancing the heat transfer in a battery system or an electrical equipment system.

[0044] Preferably, the di(undecane-6-yl) dicarboxylate A1) or tri(undecane-6-yl) tricarboxylate A2) has a kinematic viscosity at -20°C of 800 mm2 / s or less, more preferably of from 200 mm2 / s to 700 mm2 / s, even more preferably of from 300 mm2 / s to 600 mm2 / s as determined by ASTM D7042. Thanks to the low kinematic viscosity at -20°C exhibited by the 6-undecanol diester A1) or 6-undecanol triester A2), low viscosity at in low temperature range can be also imparted to a lubricating fluid composition comprising these esters according to the present invention. 202400078 Foreign Filing

[0045] Preferably, the di(undecane-6-yl) dicarboxylate A1) or tri(undecane-6-yl) tricarboxylate A2) has a kinematic viscosity at 40 °C of 40 mm2 / s or less, more preferably of from 5 mm2 / s to 30 mm2 / s, even more preferably of from 10 mm2 / s to 20 mm2 / s as determined by ASTM D7042.

[0046] Preferably, the di(undecane-6-yl) dicarboxylate A1) ortri(undecane-6-yl) tricarboxylate A2) has a flash point of 230 °C or more as determined by JIS K2265, more preferably from 232 °C to 300 °C, even more preferably of 234 °C or more, most preferably from 234 °C to 255 °C, as determined by JIS K2265. Thanks to the flash point of 230 °C or more, exhibited by the di(undecane-6-yl) dicarboxylate A1) or tri(undecane- 6-yl) tricarboxylate A2), high flash point properties can be also imparted to a lubricating fluid composition or a heat transfer fluid composition comprising these esters according to the present invention.

[0047] Preferably, the di(undecane-6-yl) dicarboxylate A1) or tri(undecane-6-yl) tricarboxylate A2) has a pour point of -40 °C or less, more preferably of -50 °C or less as determined by JIS K2269. Thanks to the pour point of -40 °C or lower exhibited by the di(undecane-6-yl) dicarboxylate A1) of Formula (I) or tri(undecane-6-yl) tricarboxylate A2) of Formula (II), low temperature viscosity properties can be also imparted to a fluid composition comprising these esters according to the present invention.

[0048] According to a preferred embodiment of the present invention, the ester A) is the ester of Formula (V) or the ester of Formula (VI), or a mixture thereof

[0049] Preferably, the ester of Formula (V) is obtained by a reaction of esterification of 6-undecanol with azelaic acid. Preferably, the ester of Formula (VI) is obtained by a reaction of esterification of 6-undecanol with adipic acid. 202400078 Foreign Filing 7

[0050] Viscosity index improver B)

[0051] According to the present invention, the viscosity index improver B) is selected from the group consisting of a polyalkyl (meth)acrylate B1) prepared by polymerizing a monomer composition comprising branched C7- C15 alkyl (meth)acrylate monomer, a polyalkyl (meth)acrylate B2) prepared by polymerizing a monomer composition comprising polybutadiene-based monomers, an acrylate-olefin copolymer B3), a polyalphaolefin B4), or a mixture thereof.

[0052] The term "(meth)acrylic acid" in the context of this invention refers to acrylic acid, methacrylic acid and mixtures of acrylic acid and methacrylic acid; methacrylic acid being preferred. The term "(meth)acrylate" refers to esters of acrylic acid, esters of methacrylic acid or mixtures of esters of acrylic acid and methacrylic acid; esters of methacrylic acid being preferred.

[0053] In the present invention, the weight-average molecular weights (Mw) of the polymers (viscosity index improver B) and pour point depressant C)) are determined by gel permeation chromatography (GPC) using polymethylmethacrylate calibration standards and the following measurement conditions: Eluent: tetra hydrofuran (THF) Operation temperature: 40 °C

[0054] Column set: the column set consists of one pre-column (PSS-SDV 100 A 10|jm 8.0 x 50 mm), and three columns (2 x PSS-SDV Linear XL 10|jm 8.0 x 300mm, 1 x PSS-SDV 100 A 10|jm 8.0 x 300mm), all columns with an average particle size of 10 pm (PSS Standards Service GmbH, Mainz, Germany) Flow rate: 1 mL / min

[0055] Injected volume: 100 pL

[0056] Instrument: Shodex GPC101 consisting of an autosampler, pump and column oven Detection device: a refractive index detector from Shodex.

[0057] Preferably, the polyalkyl (meth)acrylate B1) prepared by polymerizing a monomer composition comprising branched C7-C15 alkyl (meth)acrylate monomer has a weight-average molecular weight (Mw) of 8,000 to 150,000 g / mol, more preferably of 10,000 to 100,000 g / mol, even more preferably of 10,000 to 50,000 g / mol, most preferably from 10,000 to 30,000 g / mol (measured according to the GPC method conditions as indicated above).

[0058] Preferably, the polyalkyl (meth)acrylate B2) prepared by polymerizing a monomer composition comprising polybutadiene-based monomers has a weight-average molecular weight (Mw) of 70,000 to 300,000 g / mol, more preferably of 80,000 to 250,000 g / mol, even more preferably of 80,000 to 200,000 g / mol (measured according to the GPC method conditions as indicated above).

[0059] Preferably, the acrylate-olefin copolymer B3) has a weight-average molecular weight from 5,000 to 30,000 g / mol, preferably from 7,000 to 25,000 g / mol, even more preferably from 8,000 to 20,000 g / mol (measured according to the GPC method conditions as indicated above). 202400078 Foreign Filing 8

[0060] Preferably, the polyalphaolefin B4) has a weight-average molecular weight (Mw) of 5,000 to 150,000 g / mol, more preferably of 6,000 to 100,000 g / mol, even more preferably of 7,000 to 30,000 g / mol (measured according to the GPC method conditions as indicated above).

[0061] Preferably, the polydispersity index (PDI) of the viscosity index improver B) according to the invention is in the range from 1 .0 to 6.0, more preferably from 1 .2 to 5.0, even more preferably from 1 .4 to 4.0. The polydispersity index is defined as the ratio of weight-average molecular weight to number-average molecular weight (Mw / Mn).

[0062] Preferably, the viscosity index improver B1) is a polymer obtainable by polymerizing a monomer composition comprising linear and / or branched C12-C30 alkyl(meth)acrylate monomer and linear Ci-Ce alkyl(meth)acrylate monomer, more preferably obtainable by polymerizing a monomer composition comprising branched C12-C22 alkyl(meth)acrylate monomer and linear Ci-Ce alkyl(meth)acrylate monomer, even more preferably by polymerizing a monomer composition comprising branched C12-C15 alkyl(meth)acrylate monomer and methyl(meth)acrylate.

[0063] More preferably, the viscosity index improver B1) is a polymer obtainable by polymerizing a monomer composition comprising from 40 to 99.9 % by weight, more preferably from 45 to 99.8 % by weight, of branched C12-C15 alkyl(meth)acrylate monomer, and from 0.1 to 30 % by weight, more preferably from 0.2 to 20 % by weight, of Ci-Ce alkyl(meth)acrylate monomer. All weight percentages are given based on the total weight of the monomer composition.

[0064] Preferably, the monomer composition of the viscosity index improver B1) further comprises a monomer selected from the group consisting of (meth)acrylates of ether alcohols, aminoalkyl (meth)acrylates, aminoalkyl (meth)acrylamides or a mixture thereof. More preferably, the monomer composition of the viscosity index improver B1) further comprises 20 % by weight or less, even more preferably from 0.1 to 20 % by weight, even more preferably from 0.1 to 15 % by weight, most preferably from 0.1 to 10 % by weight of a monomer selected from the group consisting of (meth)acrylates of ether alcohols, aminoalkyl (meth)acrylates, aminoalkyl (meth)acrylamides or a mixture thereof.

[0065] Preferably, the viscosity index improver B2) is a polymer obtainable by polymerizing a monomer composition comprising: a) a polybutadiene-based macromonomer a) having a number-average molecular weight of 500 to 10,000 g / mol or a mixture thereof, b) methyl(meth)acrylate, butyl(meth)acrylate, a monomer having from 8 to 17 carbon atoms selected from a group consisting of styrene or a substituted styrene having an alkyl substituent in the side chain or a mixture thereof, c) a monomer selected from linear or branched C7-C30 alkyl(meth)acrylates, or a mixture thereof. 202400078 Foreign Filing 9

[0066] More preferably, the viscosity index improver B2) is a polymer obtainable by polymerizing a monomer composition comprising: a) 10 to 40 % by weight of a polybutadiene-based macromonomer a) having a number-average molecular weight of 500 to 10,000 g / mol or a mixture thereof, based on the total weight of the viscosity improver monomer composition, b) 50 to 70 % by weight of methyl(meth)acrylate, butyl(meth)acrylate, one monomer having from 8 to 17 carbon atoms selected from a group consisting of styrene or a substituted styrene having an alkyl substituent in the side chain or a mixture thereof, based on the total weight of the viscosity improver monomer composition, c) 0.1 to 15 % by weight of one monomer selected from linear or branched C7-C30 alkyl(meth)acrylates or a mixture thereof, based on the total weight of the viscosity improver monomer composition.

[0067] Preferably, the viscosity index improver B2) according to the invention is a polymer which comprises a first polymer, which is also referred to as backbone or main chain, and a multitude of further polymers which are referred to as side chains and are bonded covalently to the backbone. In the present case, the backbone of the polymer is formed by the interlinked unsaturated groups of the mentioned (meth)acrylic acid esters. The alkyl groups and the hydrogenated polybutadiene chains of the (meth)acrylic esters form the side chains of the polymer. The reaction product of one ester of (meth)acrylic acid and one hydroxylated hydrogenated polybutadiene or the reaction product of one (meth)acrylic acid and one hydroxylated hydrogenated polybutadiene corresponds to monomer a) and is also referred in the present invention as macromonomer or polybutadiene-based macromonomer a).

[0068] The viscosity index improver polymer B2) according to the invention can be characterized on the basis of its molar degree of branching ("f-branch"). The molar degree of branching refers to the percentage in mol% of macromonomer (monomer a)) used, based on the total molar amount of all the monomers in the monomer composition. The molar amount of the macromonomer used is calculated on the basis of the number-average molecular weight Mnof the macromonomer. The calculation of the molar degree of branching is described in detail in WO 2007 / 003238 A1 , especially on pages 13 and 14, to which reference is made here explicitly. Preferably, the polymers have a molar degree of branching fbranch of 0.1 to 5 mol%, more preferably 0.5 to 4 mol% and most preferably 1 .0 to 2.5 mol%.

[0069] Preferably, the polybutadiene-based macromonomer a) for use in accordance with the invention has a number-average molecular weight (Mn) of 1 ,000 to 6,000 g / mol, more preferably from 1 ,500 to 5,500 g / mol.

[0070] The number-average molecular weight (Mn) of the polybutadiene-based macromonomer a) is determined by gel permeation chromatography (GPC) using polybutadiene calibration standards (PSS Standards Service GmbH, Mainz, Germany) according to DIN 55672-1 using the following measurement conditions: Eluent: tetra hydrofuran (THF) Operation temperature: 35 °C

[0071] Column set: the column set consists of one pre-column (PSS-SDV; 10p; 8 x 50 mm); four PSS-SDV columns with a size of 300 x 8 mm and an average particle size of 10 pm (SDV-LXL, SDV-LinL, 2 columns 202400078 Foreign Filing 10

[0072] SDV 100 A (PSS Standards Service GmbH, Mainz, Germany)); and one solvent-peak separation column with a size of 8x100mm (KF-800D from the company Shodex)

[0073] Flow rate: 1 mL / min

[0074] Injected volume: 100 pL

[0075] Instrument: Agilent 1100 series consisting of an autosampler, pump and column oven

[0076] Detection device: a refractive index detector from Agilent 1 100 series

[0077] The polybutadiene-based macromonomers a) are esters of (meth)acrylic acid, which are either the reaction product of one ester of (meth)acrylic acid with one hydroxylated hydrogenated polybutadiene (by transesterification), or the reaction product of one (meth)acrylic acid with one hydroxylated hydrogenated polybutadiene (by direct esterification).

[0078] Preferably, the hydroxylated hydrogenated polybutadienes have a hydrogenation level of at least 99%. Preferably, the hydroxylated hydrogenated polybutadienes can be obtained according to GB 2270317.

[0079] As used herein, the term “hydroxylated hydrogenated polybutadiene” refers to a hydrogenated polybutadiene that comprises one or more hydroxyl groups. The hydroxylated hydrogenated polybutadiene may further comprise additional structural units, such as polyether groups derived from the addition of alkylene oxides to a polybutadiene or a maleic anhydride group derived from the addition of maleic anhydride to a polybutadiene. These additional structural units may be introduced into the polybutadiene when the polybutadiene is functionalized with hydroxyl groups.

[0080] Preference is given to monohydroxylated hydrogenated polybutadienes. More preferably, the hydroxylated hydrogenated polybutadiene is a hydroxyethyl- or hydroxypropyl-terminated hydrogenated polybutadiene. Particular preference is given to hydroxypropyl-terminated polybutadienes.

[0081] These monohydroxylated hydrogenated polybutadienes can be prepared by first converting butadiene monomers by anionic polymerization to polybutadiene. Subsequently, by reaction of the polybutadiene monomers with an alkylene oxide, such as ethylene oxide or propylene oxide, a hydroxy-functionalized polybutadiene can be prepared. The polybutadiene may also be reacted with more than one alkylene oxide units, resulting in a polyether-polybutadiene block copolymer having a terminal hydroxyl group. The hydroxylated polybutadiene can be hydrogenated in the presence of a suitable transition metal catalyst.

[0082] These monohydroxylated hydrogenated polybutadienes can also be selected from products obtained by hydroboration of (co)polymers of having a terminal double bond (e.g. as described in US Patent No. 4,316,973); maleic anhydride-ene-amino alcohol adducts obtained by an ene reaction between a (co)polymer having a terminal double bond and maleic anhydride with an amino alcohol; and products obtained by hydroformylation of a (co)polymer having a terminal double bond, followed by hydrogenation (e.g. as described in JP Publication No. S63-175096).

[0083] The polybutadiene-based macromonomers a) for use in accordance with the invention can be prepared by transesterification of alkyl(meth)acrylates. Reaction of the alkyl(meth)acrylate with the hydroxylated 202400078 Foreign Filing 11 hydrogenated polybutadiene forms the ester of the invention. Preference is given to using methyl(meth)acrylate or ethyl(meth)acrylate as reactant.

[0084] This transesterification is widely known. For example, it is possible for this purpose to use a heterogeneous catalyst system, such as lithium hydroxide / calcium oxide mixture (LiOH / CaO), pure lithium hydroxide (LiOH), lithium methoxide (LiOMe) or sodium methoxide (NaOMe) or a homogeneous catalyst system such as isopropyl titanate (Ti(OiPr)4) or dioctyltin oxide (Sn(OCt)2O). The reaction is an equilibrium reaction. Therefore, the low molecular weight alcohol released is typically removed, for example by distillation.

[0085] Alternatively, the polybutadiene-based macromonomers a) can be obtained by a direct esterification proceeding, for example, from (meth)acrylic acid or (meth)acrylic anhydride, preferably under acidic catalysis by p-toluenesulfonic acid or methanesulfonic acid, or from free methacrylic acid by the DCC method (dicyclohexylcarbodiimide).

[0086] Furthermore, the hydroxylated hydrogenated polybutadiene can be converted to an ester by reaction with an acid chloride such as (meth)acryloyl chloride.

[0087] Preferably, the monomers b) according to the invention are selected from methyl(meth)acrylate, butyl(meth)acrylate, one monomer having from 8 to 17 carbon atoms selected from a group consisting of styrene or a substituted styrene having an alkyl substituent in the side chain or a mixture thereof. Suitable styrene monomers having from 8 to 17 carbon atoms are selected from the group consisting of styrene, substituted styrenes having an alkyl substituent in the side chain, for example alpha-methylstyrene and alpha-ethylstyrene, substituted styrenes having an alkyl substituent on the ring, such as vinyltoluene and para-methylstyrene, halogenated styrenes, for example monochlorostyrenes, dichlorostyrenes, tribromostyrenes and tetra bromostyrenes, nitrostyrene; styrene being preferred.

[0088] Regarding the monomers c), the term “C7-30 alkyl(meth)acrylates” refers to esters of (meth)acrylic acid with linear or branched alkyl chain having 7 to 30 carbon atoms. The term encompasses individual (meth)acrylic esters with an alcohol of a particular length, and likewise mixtures of (meth)acrylic esters with alcohols of different lengths.

[0089] Suitable C7-30 alkyl(meth)acrylates include, for example, 2-butyloctyl(meth)acrylate, 2- hexyloctyl(meth)acrylate, decyl(meth)acrylate, 2-butyldecyl(meth)acrylate, 2-hexyldecyl(meth)acrylate, 2- octyldecyl(meth)acrylate, undecyl(meth)acrylate, 5-methylundecyl(meth)acrylate, dodecyl(meth)acrylate,

[0090] 2-methyldodecyl(meth)acrylate, 2-hexyldodecyl(meth)acrylate, 2-octyldodecyl (meth)acrylate, tridecyl(meth)acrylate, 5-methyltridecyl(meth)acrylate, tetradecyl(meth)acrylate, 2- decyltetradecyl(meth)acrylate, pentadecyl(meth)acrylate, hexadecyl(meth)acrylate, 2- methylhexadecyl(meth)acrylate, 2-dodecylhexadecyl(meth)acrylate, heptadecyl(meth)acrylate, 5- isopropylheptadecyl(meth)acrylate, 4-terf-butyloctadecyl(meth)acrylate, 5-ethyloctadecyl(meth)acrylate,

[0091] 3-isopropyloctadecyl(meth)acrylate, octadecyl(meth)acrylate, 2-decyloctadecyl(meth)acrylate, 2- tetradecyloctadecyl(meth)acrylate, nonadecyl(meth)acrylate, eicosyl(meth)acrylate, cetyleicosyl(meth)acrylate, stearyleicosyl(meth)acrylate, docosyl(meth)acrylate, 202400078 Foreign Filing 12 eicosyltetratriacontyl(meth)acrylate, 2-decyl-tetradecyl(meth)acrylate, 2-decyloctadecyl(meth)acrylate, 2- dodecyl-1-hexadecyl(meth)acrylate, 1 ,2-octyl-1-dodecyl(meth)acrylate, 2- tetradecylocadecyl(meth)acrylate, 1 ,2-tetradecyl-octadecyl(meth)acrylate and 2-hexadecyl- eicosyl(meth)acrylate, n-tetracosyl(meth)acrylate, n-triacontyl(meth)acrylate and / or n- hexatriacontyl(meth)acrylate.

[0092] Particularly preferred monomers c) are (meth)acrylic esters of a linear C12-14 alcohol mixture (C12-14 alkyl methacrylate), (meth)acrylic esters of a linear C16-18 alcohol mixture (C16-18 alkyl methacrylate) or a mixture thereof.

[0093] In the context of the present invention, the term “C12-14 alkyl(meth)acrylates” refers to esters of (meth)acrylic acid and linear or branched alcohols having 12 to 14 carbon atoms. The term encompasses individual (meth)acrylic esters with an alcohol of a particular length, and likewise mixtures of (meth)acrylic esters with alcohols of different lengths. Suitable C12-14 alkyl(meth)acrylates include, for example, dodecyl methacrylate, 2-methyldodecyl methacrylate, tridecyl methacrylate, 5-methyltridecyl methacrylate and / or tetradecyl methacrylate.

[0094] Likewise, the C16-18 alkyl(meth)acrylates include, for example, may also independently be selected from the group consisting of hexadecyl (meth)acrylate, 2-methylhexadecyl (meth)acrylate, heptadecyl (meth)acrylate, 5-isopropylheptadecyl (meth)acrylate, 4-tert-butyloctadecyl (meth)acrylate, 5- ethyloctadecyl (meth)acrylate, 3-isopropyloctadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, cetyleicosyl (meth)acrylate, stearyleicosyl (meth)acrylate, docosyl (meth)acrylate, behenyl (meth)acrylate, eicosyltetratriacontyl (meth)acrylate, cycloalkyl (meth)acrylates, 2,4,5-tri-t-butyl-3-vinylcyclohexyl (meth)acrylate, and 2,3,4,5-tetra-t-butylcyclohexyl (meth)acrylate. Particularly preferred C16-18 alkyl(meth)acrylates is stearyleicosyl (meth)acrylate.

[0095] Preferably, the monomer composition of the viscosity index improver B2) further comprises a monomer d) selected from the group consisting of (meth)acrylates of ether alcohols, aminoalkyl (meth)acrylates, aminoalkyl (meth)acrylamides or a mixture thereof. More preferably, the monomer composition of the viscosity index improver B2) further comprises 20 % by weight or less, even more preferably from 0.1 to 20 % by weight, even more preferably from 0.1 to 15 % by weight, most preferably from 0.1 to 10 % by weight of monomer d) selected from the group consisting of (meth)acrylates of ether alcohols, aminoalkyl (meth)acrylates, aminoalkyl (meth)acrylamides, or a mixture thereof.

[0096] Preferably, the acrylate-olefin copolymer B3) comprises:

[0097] 65 to 90 % by weight, based on the total weight of the copolymer B3), of monomer units derived from an acrylate of Formula (III)

[0098] Formula (III) wherein R3 means a linear or branched alkyl group having from 6 to 12 carbon atoms, and 202400078 Foreign Filing 13

[0099] 10 to 35 % by weight, based on the total weight of the copolymer B3), of monomer units derived from a non-functionalized alpha-olefin of Formula (IV),

[0100] Formula (IV) wherein R4 means a linear alkyl group having from 6 to 16 carbon atoms, wherein the copolymer B3) comprises from 0 to 30 % by weight of monomer units derived from monomers with linear alkyl group having more than 8 carbon atoms, based on the total weight of the copolymer B3), and wherein the copolymer has a kinematic viscosity at 100°C from 80 to 600 mm2 / s according to ASTM D 445.

[0101] According to one preferred aspect of the invention, it is preferred that R3 in the acrylate monomer of Formula (III) is a linear or branched alkyl group having from 6 to 10 carbon atoms, more preferably linear or branched alkyl group having 8 to 10 carbon atoms. Particularly preferred acrylates of Formula (III) are 2-ethylhexyl acrylate, 2-propylheptyl acrylate, n-octylacrylate or a mixture thereof. It is preferred that the VII acrylateolefin copolymer B3) comprises from 65 to 85 % by weight, more preferably from 70 to 80 % by weight, of monomer units derived from the acrylate monomer of Formula (III), based on the total weight of the copolymer B3).

[0102] According to the present invention, it is preferred that the VII acrylate-olefin copolymer B3) comprises from 15 to 35 % by weight, more preferably from 20 to 30 % by weight, of monomer units derived from the nonfunctionalized alpha-olefin of Formula (IV), based on the total weight of the copolymer B3). Particularly preferred non-functionalized alpha-olefins of Formula (IV) are selected from the group consisting of decene, dodecene, tetradecene, hexadecane, or a mixture thereof.

[0103] Optionally, the monomer composition to prepare the acrylate-olefin copolymer B3) can also comprise up to 10 % by weight of monomer derived from at least one monomer selected from the list consisting of methacrylamides, fumarates, maleates or a mixture thereof, based on the total weight of the monomer composition.

[0104] The method for preparing the acrylate-olefin copolymer B3) is described for example in EP4015604.

[0105] Pour point depressant C)

[0106] According to the present invention, the pour point depressant C) is a polyalkyl(meth)acrylate obtainable by polymerizing a monomer composition consisting of a mixture of linear C7-C15 alkyl(meth)acrylates and linear or branched C16-C30 alkyl(meth)acrylates, and optionally linear Ci-Ce alkyl(meth)acrylates. 202400078 Foreign Filing 14

[0107] Pour point depressants (PPD) are additives that improve the low temperature performance of an oil by modifying the wax crystallization process.

[0108] Preferably, the polymer C) is a polyalkyl(meth)acrylate polymer having a weight-average molecular weight (Mw) of 10,000 to 200,000 g / mol (measured according to the GPC method conditions as indicated above). A detailed description of the GPC method is provided above. More preferably, the polymer C) is a polyalkyl(meth)acrylate polymer having a weight-average molecular weight (Mw) of 20,000 to 150,000 g / mol, even more preferably, of 30,000 to 100,000 g / mol (measured according to the GPC method conditions as indicated above).

[0109] Preferably, the polymer C) is obtainable by polymerizing a monomer composition consisting of: e) 20 to 99 % by weight of a monomer selected from linear C7-C15 alkyl(meth)acrylates or a mixture thereof, based on the total weight of the monomer composition, f) 1 to 80 % by weight of a monomer selected from linear or branched C16-C30 alkyl(meth)acrylates or a mixture thereof, based on the total weight of the monomer composition, and g) 0 to 20 % by weight of linear Ci-Ce alkyl(meth)acrylates.

[0110] More preferably, the polymer C) is obtainable by polymerizing a monomer composition consisting of: e) 80 to 98 % by weight of one monomer selected from linear C12-C14 alkyl(meth)acrylates, based on the total weight of the monomer composition, f) 2 to 20 % by weight of at least one monomer selected from linear C16-C22 alkyl(meth)acrylates, based on the total weight of the monomer composition.

[0111] Unless otherwise noted, the weight amounts of the monomers are given relative to the total amount of monomers used, namely, the total weight of the monomer composition to prepare the polymer C).

[0112] Preferably, the polydispersity index (PDI) of the pour point depressant polymer C) according to the invention is in the range from 1 .0 to 6.0, more preferably from 1 .2 to 5.0, even more preferably from 1 .4 to 4.0. The polydispersity index is defined as the ratio of weight-average molecular weight to number-average molecular weight (Mw / Mn).

[0113] Base oil D)

[0114] The lubricating fluid composition may also preferably comprise a base oil D).

[0115] Base oils correspond to lubricant base oils, mineral, synthetic or natural, animal or vegetable oils suited to their use / chosen depending on the intended use.

[0116] The base oils, which may be used in formulating the lubricating fluid compositions according to the present invention, include, for example, conventional base stocks selected from API (American Petroleum Institute) base stock categories known as Group I, Group II, Group III and / or Group IV (different from the PAG VII B4)). The Group I and II base stocks are mineral oil materials (such as paraffinic and naphthenic oils) having 202400078 Foreign Filing 15 a viscosity index (or VI) of less than 120. Group I is further differentiated from Group II in that the latter contains greater than 90% saturated materials and the former contains less than 90% saturated material (that is more than 10% unsaturated material). Group III is considered the highest level of mineral base oil with a VI of greater than or equal to 120 and a saturates level greater than or equal to 90%. Preferably the base oil included in the lubricating fluid composition of the present invention is selected from the group consisting of API Group II and III base oils. Most preferably, the lubricant composition comprises an API Group III base oil. Group IV base oils are polyalphaolefins (PAG) different from the PAO VII B4). Preferably, the API Group IV base oil is a polyalphaolefin having a weight-average molecular weight of less than 1 ,000 g / mol. These base oils can be used individually or as a mixture.

[0117] Preferably, the lubricating fluid composition comprises from 0 to 85 % by weight, more preferably from 0.1 to 80 % by weight, even more preferably from 5 to 80 % by weight, most preferably from 10 to 75 % by weight of a base oil D), based on the total weight of the lubricating fluid composition.

[0118] Further additives E)

[0119] The lubricating fluid composition according to the present invention may also comprise additional additives E) suitable for use according to the final technical application. The additive E) is selected from the group consisting of dispersants, demulsifiers, defoamers, lubricity additives, friction modifiers, antioxidants, detergents, dyes, corrosion inhibitors, odorants, or a mixture thereof.

[0120] Preferably, the lubricating fluid composition comprises from 0 to 15 % by weight, more preferably from 0.1 to 15.0 % by weight, even more preferably from 0.5 to 12.0 % by weight, most preferably from 1 to 10 % by weight, of an additive E), based on the total weight of the lubricating fluid composition.

[0121] Preparation of the di(undecane-6-yl) dicarboxylate and tri(undecane-6-yl) tricarboxylate according to the invention

[0122] In the present invention, the di(undecane-6-yl) dicarboxylate A1) of Formula (I) or tri(undecane-6-yl) tricarboxylate A2) of Formula (II) may be prepared by direct esterification reaction of 6-undecanol with an acid or its anhydride, or by the transesterification reaction of 6-undecanol with dimethyl dicarboxylate, diethyl dicarboxylate, trimethyl tricarboxylate, or triethyl tricarboxylate. For example, di(undecane-6-yl) dicarboxylate A1) of Formula (I) or tri(undecane-6-yl) tricarboxylate A2) of Formula (II) can be prepared by the esterification as described in EP2155754B1 .

[0123] The direct or transesterification process according to the invention can preferably be carried out by classical esterification methods, such as non-catalyzed, catalyzed with enzymes, acid- or base-catalyzed.

[0124] Acid catalyzed esterification can be done, for example, with Bronsted- or Lewis acids. Examples are hydrochloric acid, sulfonic acids (such as methane sulfonic acid, para-toluene sulfonic acid, 10- camphersulfonic acids), sulfuric acid, phosphoric acid, hypophosphorous acid, phosphonic acid, phosphorous acid, phosphinic acid, tin (II) salts such as tin oxide, zinc salts such as zinc oxide or zinc 202400078 Foreign Filing 16 acetylacetonate, zirconium salts, titanium alkoxides such as titanium butoxide. Also, polymer- / resin-based or supported catalysts can be used, such as sulfonated polystyrene or sulfonated fluoropolymer (Nation- Fl). The above-mentioned acids can preferably be used in combination.

[0125] Base catalyzed esterification can for example be carried out with alkaline, earth alkaline or ammonium salts, such as the respective hydroxides, oxides, phosphates or carbonates. Furthermore, amines or the alkaline salts of alcohols or of organic acids can be used as bases. The above-mentioned bases can preferably be used in combination.

[0126] The direct esterification or transesterification reaction by acid or based catalysts is done at temperature of from 50 °C to 260 °C, preferably from 80 °C to 200 °C. A vacuum and / or a flow of an inert gas like nitrogen or argon is preferably applied to support the removal of condensation water, methanol or ethanol and acceleration of reaction.

[0127] For removal of the water, methanol or ethanol generated during the direct or transesterification process, it is preferred that the unreacted acid, methyl ester, or ethyl ester is distilled off from the reaction mixture. An example of the removal process of acid catalyst and / or unreacted acid, methyl ester, or ethyl ester is given below in the experimental part.

[0128] Preferably, after the esterification reaction, a neutralization, washing or adsorption process can be done if needed. Examples of neutralizers include an aqueous solution of sodium hydroxide and potassium hydroxide, preferably, an aqueous solution of sodium hydroxide. The concentration of the aqueous solution of sodium hydroxide is preferably from 10 wt% to 50 wt%, more preferably from 20 wt% to 40 wt%.

[0129] Preferably, the aqueous layer containing neutralizing salts can be removed by separators and / or centrifuges, adsorbents and filtration. Preferably, the obtained organic layer can be additionally washed with water. The removal of water can be done using the aforementioned methods. Preferably, moisture contained in the organic layer can be removed by evaporation under reduced pressure and / or by adsorbent and filtration.

[0130] The esterification to prepare present invention is not limited to above-mentioned methods and methods in inventive examples described later.

[0131] Method for preparing the lubricating fluid composition according to the present invention

[0132] The present invention also relates to a method for preparing the lubricating fluid compositions according to the present invention, in which the components A), B), C), and optionally components D) and / or E), are mixed together to obtain the lubricating fluid composition.

[0133] Preferably, the components are mixed at a temperature from 60 C to 80 C, more preferably for at least one hour. 202400078 Foreign Filing 17

[0134] Use as heat transfer fluid

[0135] In recent years, energy shortage and environmental concerns have had a tremendous impact on technological advancement. The increase of environmental awareness has led to a growing interest in so- called green technologies, especially in the automobile industry. The demand for emission-free vehicles fueled by renewable energy sources, such as pure electric vehicles (EVs), hybrid electric vehicles (HEVs) and fuel cell electric vehicles, has gradually become more significant and is anticipated to increase drastically in the next 20 years. The energy for such vehicles is provided and stored in batteries having a high specific energy density. Various batteries are available for EVs and HEVs, such as lead-acid, zinc / halogen, metal / air, sodium-beta, nickel metal hydride (Ni-MH) and lithium-ion (Li-ion). To increase the performance of electric vehicles, large-scale batteries with a high current discharge are required. Due to the size and power output, these large-scale batteries generate a large amount of heat during rapid charge and discharge cycles at high current levels. Thus, batteries have to be thermally managed by cooling or dissipating heat to avoid battery malfunction and increase the lifetime of the battery.

[0136] Furthermore, the performance of the battery is temperature dependent. Depending on their type, batteries perform optimally only with a particular temperature range. Therefore, a proper thermal management allows optimizing battery performance.

[0137] As shown in the experimental part, it has been advantageously observed that the lubricating fluid composition according to the present invention can be used for e-driveline fluid. Thus, according to another aspect of the present invention, the present invention also relates to the use of the ester A) as defined herein throughout the description or the lubricating fluid composition according to the present invention in a heat transfer fluid for direct or indirect cooling system of computers, servers such as in data center computers, transformers, capacitors, or electric vehicles powertrain, wherein the direct or indirect cooling system is selected from axles, differentials, transmissions, electric motors, fluid-filled power cables, battery pack or power electronics.

[0138] Use of the esters A) or the lubricating fluid composition according to the present invention to improve efficiency of a gear box and / or an electric device

[0139] According to another aspect of the present invention, the present invention also relates to a use of the di(undecane-6-yl) dicarboxylate A1) of Formula (I) or tri(undecane-6-yl) tricarboxylate A2) of Formula (II) or the lubricating fluid composition according to the present invention to improve efficiency of a gear box and / or an electric device.

[0140] Preferably, the electric device is selected from a group consisting of electric batteries, electric motors, electric transformers, electric capacitors, fluid-filled transmission lines, fluid-filled power cables, computers, data servers, battery pack or power electronics such as electric power converters. 202400078 Foreign Filing 18

[0141] Method of improving efficiency of gear box and / or electric devices in a cooling system of data center or an electric vehicle according to the invention

[0142] According to another aspect of the present invention, the present invention also relates to a method of improving efficiency of gear box and / or electric devices in a cooling system of data center or an electric vehicle. The method comprises using the lubricating fluid composition or the ester A) according to the present invention in the electronic powertrain or cooling system of data center.

[0143] Method of reducing friction between two or more metal parts according to the invention

[0144] Lubricants are compositions that reduce friction between surfaces. In addition to allowing freedom of motion between two surfaces and reducing mechanical wear of the surfaces, a lubricant also may inhibit corrosion of the surfaces and / or may inhibit damage to the surfaces due to heat or oxidation. Examples of lubricant compositions include, but are not limited to, engine oils, transmission fluids, gear oils, industrial lubricating oils, greases and metalworking oils. Using the lubricating fluid composition according to the present invention is thus important for energy efficiency and durability of the device that is being lubricated.

[0145] According to another aspect of the present invention, the present invention also relates to a method of reducing friction between two or more metal parts of an engine, a gearbox or pump of an automobile, a wind turbine, or a hydraulic system, the method comprising using the lubricating fluid composition according to the present invention in said engine, gearbox or pump of an automobile, wind turbine, or hydraulic system.

[0146] Method of enhancing the heat transfer by using the esters A) or the lubricating fluid composition according to the invention in a battery system or other electrical equipment systems

[0147] According to another aspect of the present invention, the present invention relates to a method of enhancing the heat transfer in a battery system or an electrical equipment system, the method comprising using the esters A) or the lubricating fluid composition according to the invention in the battery system or the electrical equipment system.

[0148] Preferably, the battery system or the electrical equipment system is a direct or indirect cooling system of computers, servers, data center device, transformers, capacitors, or electric vehicles powertrain, wherein the direct or indirect cooling system is selected from axles, differentials, transmissions, electric motors, fluid-filled power cables, battery pack or power electronics.

[0149] Method of lowering the pour point of a lubricant formulation

[0150] According to another aspect of the present invention, the present invention also relates to a method of lowering the pour point of a lubricating fluid formulation by adding the esters A) of the present invention to said lubricating fluid composition. 202400078 Foreign Filing 19

[0151] EXPERIMENTAL PART

[0152] The invention is further illustrated in detail hereinafter with reference to examples and comparative examples, without any intention to limit the scope of the present invention.

[0153] Cp specific heat; expressed by SI unit: J / (kg K)

[0154] Density @ 15 °C density at 15 °C according to ASTM D4052

[0155] Density @ 100 °C density at 100 °C according to ASTM D4052

[0156] Durasyn 180R high viscosity polyalphaolefin (PAO), which is a fully synthesized and hydrogenated hydrocarbon base fluid produced from C10 linear alpha olefin feedstocks with a kinematic viscosity at 100 °C of 100 mm2 / s

[0157] FP (COC) flash point according to JIS K2265 k thermal conductivity; expressed by SI unit: W / (m K)

[0158] KV-20 kinematic viscosity at -20°C according to ASTM D7042

[0159] KV40 kinematic viscosity at 40°C according to ASTM D7042

[0160] KV100 kinematic viscosity at 100°C according to ASTM D7042

[0161] AKV100 kinematic viscosity loss ratio at 100°C after the test following JASO M347 high power method for 2 hours. p @ MTM friction coefficient tested by Mini Traction Machine (method explained below)

[0162] Ap variation in the coefficient of friction

[0163] Mn number-average molecular weight

[0164] Mw weight-average molecular weight n.m. means “not measured”

[0165] PDI polydispersity Index pour point according to JIS K2269

[0166] Mouromtseff @ 100°C Mouromtseff number in turbulent state flow at 100 °C (method explained below)

[0167] PPD Pour Point Depressant

[0168] PPD No. 1 polyalkyl(meth)acrylate prepared by polymerizing 94 wt% of linear C12-C14 alkyl(meth)acrylate and 6 wt% of stearyl methacrylate (linear C16-C18 alkyl methacrylate)

[0169] VII Viscosity Index Improver

[0170] VII No. 1 polyalkylmethacrylate comprising 88 wt% of linear and branched C12-C15 alkylmethacrylate (weight ratio linear to branched 40:60) and 12 wt% of methyl methacrylate

[0171] VII No. 2 acrylate-olefin copolymer comprising 77 wt% of 2-ethyl hexyl acrylate and 23 wt% of 1 -decene

[0172] VII No. 3 polyalkylmethacrylate comprising 99.8 wt% of linear and branched C12-C15 alkylmethacrylate (weight ratio linear to branched 40:60) and 0.2 wt% of methyl methacrylate

[0173] Yubase 4 API Group III hydrorefined mineral oil with a KV40 of 19.5 mm2 / s and KV100 of

[0174] 4.3 mm2 / s (manufactured by SK enmove) 202400078 Foreign Filing 20

[0175] Yubase 6 API Group III hydrorefined mineral oil with a KV40 of 36.0 mm2 / s and KV100 of

[0176] 6.4 mm2 / s (manufactured by SK enmove)

[0177] Test methods

[0178] Molecular weights of the esters

[0179] The molecular weights of the di- and tri-esters of Formula (I) and Formula (II) according to the present invention, as well as any comparative esters, are determined based on the structure of the obtained ester. The sum of the molar mass of all atoms in the ester is equal to the molecular mass or molecular weight of said ester.

[0180] Weight-average molecular weights of the polymers

[0181] The weight-average molecular weights (Mw) of the polymers (viscosity index improver B) and pour point depressant C)) are determined by gel permeation chromatography (GPC) using polymethylmethacrylate calibration standards. Detailed measurement conditions are provided above in the detailed description part.

[0182] Flash Points

[0183] Flash point (FP) was measured by Cleveland open-cup (COC) method according to JIS K2265.

[0184] Kinematic viscosities

[0185] The kinematic viscosities of the obtained esters, as well as of the lubricating fluid compositions comprising said esters, were measured at -20°C, 40°C and 100°C respectively according to ASTM D7042 with no deviations.

[0186] Determination of Mouromtseff number in turbulent state flow at 100 °C

[0187] The Mouromtseff number in turbulent state flow at 100 °C is a dimensionless figure and given by the following formula wherein p : density; expressed by SI unit: kg / m3, k: thermal conductivity; expressed by SI unit: W / (m K), Cp: specific heat; expressed by SI unit: J / (kg K), p: dynamic viscosity; expressed by SI unit: Pa s = N s / m2, a: 0.8 , b: 0.67 ,d: 0.33, e: 0.47.

[0188] Determination of the reduction in friction via mini traction machine

[0189] Friction coefficient was tested by Mini traction machine. The data points at 0.8 m / s and 50 % of slide-roll ratio with Ball on Disk at 80°C under 35N were confirmed.

[0190] The coefficient of friction was measured using a Mini traction machine named MTM2 from PCS Instruments following the test method described in Table 1 below. SRR refers to the Sliding Roll Ratio and is defined as (Ubaii-Udisc) / U wherein (Ubaii- Udisc) represents the sliding speed and U represents the entrainment speed, given by U = (Ubaii + Udisc) / 2. Stribeck curves for each sample were measured according to protocol in Table 202400078 Foreign Filing 21

[0191] 1. Ball and disc were not replaced between the running-in and the test. According to MTM Method, the friction coefficient was recorded over the complete range of speed for each blend and a Stribeck curve is obtained.

[0192] Table 1 : Protocol to measure the Stribeck curves

[0193] Running-in

[0194] Test conditions

[0195] Pour Points

[0196] Pour point (PP) was measured according to JIS K2269.

[0197] Synthesis and performance of esters

[0198] Inventive examples: Synthesis of a 6-undecanol diesters A1) according to the invention

[0199] Working example 1 (Working Ex. 1)

[0200] To a 4-neck 500 ml round-bottomed flask was added 6-Undecanol 251 .33g (1 .46mol, 1 .0 eq) and dimethyl adipate 1 15.49 g (0.66mol, 0.45 equiv.), heated up to 70°C under vacuum, Then, it was cooled to room temperature and titanium (IV) butoxide (1.20g, 0.0048 equiv.) were added at room temperature. The resulting mixture was heated at reflux with stirring under nitrogen atmosphere until its producing methanol stops. The methanol produced in the reaction was collected in a Dean-Stark trap. The cooled mixture was added with deionized water, heated up to 90°C for about 1 hour. Afterwards, cooled mixture was added 202400078 Foreign Filing 22

[0201] Decalite 4308 and filtered with Buchner funnel. Solvent or remained raw materials were further removed by heating the crude product with stirring under high vacuum.

[0202] Working example 2 (Working Ex.2)

[0203] To a 4-neck 500 ml round-bottomed flask was added Azelaic acid (141 .18g, 0.75mol, 1 .0 eq), 6-Undecanol (273.10g, 1.57mol, 2.1 eq) and p-toluene sulfonic acid monohydrate (4.28g, 0.023mol, 0.03 eq). at room temperature. The resulting mixture was heated at reflux with stirring under nitrogen atmosphere until its producing water stops. The water produced during the reaction was condensed and collected in a Dean- Stark trap. The cooled mixture was added with sodium hydroxide aqueous solution (4wt% NaOH) to neutralize the acid catalyst and extracted. This extraction process was repeated three times. Collected organic phase was dried with KYOWAAD™700 and filtered with Buchner funnel. Remained raw materials were further removed by heating the crude product with stirring under high vacuum.

[0204] Working example 3 (Working Ex.3)

[0205] To a 4-neck 500 ml round-bottomed flask was added 6-Undecanol (289.48g, 1 .68mol, 1.0 equiv.) and dimethyl sebacate (161.23g, 0.70mol, 0.42 equiv.), heated up to 75°C under vacuum. Then, it was cooled to room temperature and titanium (IV) butoxide (1 .36g, 0.0048 equiv.) were added at room temperature. The resulting mixture was heated at reflux with stirring under nitrogen atmosphere until its producing methanol stops. The methanol produced in the reaction was collected in a Dean-Stark trap. The cooled mixture was added with deionized water, heated up to 90°C for about 1 hour. Afterwards, cooled mixture was added Decalite 4308 and filtered with Buchner funnel. Solvent or remained raw materials were further removed by heating the crude product with stirring under high vacuum.

[0206] Comparative examples

[0207] Comparative example 1 (Comp. Ex.1)

[0208] Comp. Ex. 1 corresponds to glycerol tris(2-ethylhexanoate), a pure synthetic tri-ester base stock

[0209] Comparative example 2 (Comp. Ex.2)

[0210] Comp. Ex.2 corresponds to 2-ethylhexyl dodecanoate a pure synthetic diester base stock

[0211] Comparative example 3 (Comp. Ex.3)

[0212] For the synthesis of Comp. Ex.3, 265.36g (1.54mol) of 6-undecanol was mixed with 102.31g (0.70 mol) of dimethyl succinate continuing with the same procedure as for the synthesis of the Working Ex.3 as disclosed above.

[0213] Comparative example 4 (Comp. Ex.4)

[0214] For the synthesis of Comp. Ex.4, 86.90g (0.50mol) of 6-undecanol was mixed with 50.10 g (0.19mol) of dimethyl dodecanedioate continuing with the same procedure as for the synthesis of the Working Ex.3 as disclosed above.

[0215] All examples and comparative ester examples and their respective physical / chemical properties are shown in Table 2 below. 202400078 Foreign Filing 23

[0216] Table 2: Comparative and working ester examples: Synthesis and performance of esters, and comparison with API Group III mineral oil n.m. means “not measured

[0217] 202400078 Foreign Filing 24

[0218] Results Discussion

[0219] The 6-undecanol esters of the invention (Working Examples 1 to 3) all exhibit a good combination of low viscosities in low to high temperature range (see very good values of KV at -20 °C, KV at 40 °C and KV at 100 °C in Table 2 above), as well as high flash point properties higher than 230 C. Furthermore, they also exhibit great low temperature performance with excellent pour point values, under minus 40 C (-40 C).

[0220] In contrast, the comparative esters (Comp. Ex. 1 to 4) do not show any results in which all the aboveindicated properties are combined and thus do not perform efficiently.

[0221] Comparative Example 2 has in general good properties, but its density value measured at 15 °C is high, which leads to a lower shear stability when mixed in a lubricating fluid composition. Generally, higher density esters are more hydrophilic and prohibit polar viscosity index improvers such as poly alkyl (meth)acrylates from shrinking in the hydrophobic lubricant compositions. Thus, viscosity index improvers exist in more swelled form, leading to being less shear stable.

[0222] The comparative 6-undecanol esters (Comp. Ex. 3 with alcohol reactant: 6-undecanol) show a low viscosity. However, it has a low viscosity index value (47) and a bad low temperature performance with pour point value (-27.5°C).

[0223] The comparative 6-undecanol esters (Comp. Ex. 4 with alcohol reactant: 6-undecanol) show a high viscosity index value (147). However, it has a thick kinematic viscosity @100 °C(5.3 mm2 / s) and a very bad low temperature performance with pour point value ( -5 °C).

[0224] In Table 2 above, the inventive esters according to the invention have also been compared with the base oil Yubase 4 (API Group 3 base oil). The base oil reference Yubase 4 has the same range of viscosity at 100 °C as the inventive esters according to the invention. Yubase 4 also has similar viscosity index values and high flash point as the inventive esters. However, Yubase 4 has a very bad low temperature performance with a pour point value of only -15 °C. Furthermore, Yubase 4 has a low Mouromtseff value much lower than the inventive esters at the same viscosity range which shows that Yubase 4 has similar poor heat transfer properties as any hydrocarbon based base fluid. In contrast, the inventive esters show better heat transfer property with high Mouromtseff values at 100 °C measured at the same viscosity range.

[0225] These results show that the esters do not only need to be 6-undecanol diesters, but also need to have the right alkylene chain length between ester bonds (Ri in formula (I) of diesters A1) according to the invention).

[0226] Examples of lubricating fluid compositions

[0227] To prepare the lubricating fluid compositions of the present invention, the components listed in Table 3 below are mixed together at 60°C until the resulting mixture is homogeneous.

[0228] The physical properties of the lubricating fluid compositions are also shown in Table 3 below. 202400078 Foreign Filing 25

[0229] Table 3: Lubricating fluid compositions comprising comparative or working ester examples of Table 2, and their performance as drive line fluids

[0230] 202400078 Foreign Filing 26

[0231] Result discussion from the results shown in Table 3 above:

[0232] The lubricating fluid composition of Comp. F1 , prepared with the same VII and PPD (and same amounts) as inventive lubricating fluid composition Inv. F1 , Inv. F2, and Inv. F4, but without any 6-undecanol ester according to the invention, shows a very high Brookfield value of 553,600 mPa.s.

[0233] Although the lubricating fluid compositions of Comp. F2, prepared with the same VII and PPD (and same amounts) as inventive lubricating fluid compositions Inv. F1 , Inv. F2, and Inv. F4 has good flash point properties, it disadvantageously shows no improvement in Ap. Additionally, it shows a worse shear stability than all the inventive lubricating fluid compositions and its Brookfield viscosity is not low enough.

[0234] In contrast, it can be observed that the lubricating fluid compositions according to the invention (Inv. F1-F8) comprising the 6-undecanol diesters A1) of formula (I) according to the invention do not only show excellent low viscosities in low to high temperature range, but also have high flash point properties and great antifriction properties, while still maintaining high shear stability. It is confirmed that it is possible to formulate fluids having lower friction compared to conventional fluids according to the state of the art, while keeping their flash point and shear stability high enough without any concern by using the lubricating fluid compositions as defined in the present invention.

Claims

202400078 Foreign Filing 27CLAIMS1 . A lubricating fluid composition comprising:A) an ester selected from the group consisting of di(undecane-6-yl) dicarboxylate A1) of Formula (I), tri(undecane-6-yl) tricarboxylate A2) of Formula (II), or a mixture thereof,wherein R1 is selected from a linear or branched alkylene group having from 4 to 9 carbon atoms,wherein R2 is selected from a hydrocarbon group having from 1 to 3 carbon atoms,B) a viscosity index improver selected from the group consisting of a polyalkyl (meth)acrylate B1) prepared by polymerizing a monomer composition comprising branched C7-C15 alkyl(meth)acrylate monomer, a polyalkyl (meth)acrylate B2) prepared by polymerizing a monomer composition comprising polybutadiene-based monomers, an acrylate-olefin copolymer B3), a polyalphaolefin B4), or a mixture thereof, andC) a pour point depressant polymer which is a polyalkyl (meth)acrylate prepared by polymerizing a monomer composition consisting of a mixture of linear C7-C15 alkyl(meth)acrylates and linear and / or branched C16-C30 alkyl(meth)acrylates, and optionally linear C1-C6 alkyl(meth)acrylates.202400078 Foreign Filing 282. The lubricating fluid composition according to claim 1 , wherein the lubricating fluid composition comprises from 5 to 80 % by weight, preferably from 8 to 75 % by weight, more preferably from 10 to 70 % by weight, of di(undecane-6-yl) dicarboxylate A1), tri(undecane-6-yl) tricarboxylate A2) or a mixture thereof, based on the total weight of the lubricating fluid composition.

3. The lubricating fluid composition according to claim 1 or 2, wherein the lubricating fluid composition comprises from 5 to 60 % by weight, preferably from 8 to 50 % by weight, more preferably from 10 to 45 % by weight, of the viscosity index improver B), based on the total weight of the lubricating fluid composition.

4. The lubricating fluid composition according to any one of claims 1 to 3, wherein the lubricating fluid composition comprises from 0.1 to 5 % by weight, preferably from 0.1 to 3 % by weight, more preferably from 0.1 to 2 % by weight, of the pour point depressant C), based on the total weight of the lubricating fluid composition.

5. The lubricating fluid composition according to any one of claims 1 to 4, wherein the ester A) is selected from the group consisting of di(undecyl-6-yl)adipate, di(undecyl-6-yl)2,2-dimethylpentanedioate, di(undecyl-6-yl)3,3-dimethy pentanedioate, di(undecyl-6-yl)heptanedioate, di(undecyl-6-yl)octanedioate, di(undecyl-6-yl)2,2-dipropyl malonate, di(undecan-6-yl)3-ethyl-3-methylpentanedioate, di(undecyl-6-yl) trimethyl adipate, tri(undecan-6-yl) methanetricarboxylate, tri(undecan-6-yl) propane-1 ,2, 3-tricarboxylate, di(undecyl-6-yl)nonanedioate, and di(undecyl-6-yl)decanedioate, or a mixture thereof.

6. The lubricating fluid composition according to any one of claims 1 to 5, wherein the di(undecane-6-yl) dicarboxylate A1) or the tri(undecane-6-yl) tricarboxylate A2) has a flash point of 230 °C or more, as determined by JIS K2265.

7. The lubricating fluid composition according to any one of claims 1 to 6, wherein the lubricating fluid composition further comprises a base oil belonging to Groups I to IV in the base oil categories defined by the American Petroleum Institute and selected from Group I base oil, Group II base oil, Group III base oil, Group IV base oil different from the polyalphaolefin B4), or a mixture thereof.

8. The lubricating fluid composition according to any one of claims 1 to 7, wherein the lubricating fluid composition further comprises an additive E) selected from a group consisting of extreme pressure agents, anti-wear agents, friction modifiers, defoamers, seal compatibility agents, antioxidants, yellow metal passivators, rust inhibitors, electrostatic discharge depressants, demulsifiers, dyes, or a mixture thereof.202400078 Foreign Filing 299. Ester of Formula (V) or of Formula (VI)10. Use of the ester as defined in any one of claims 1 , 5, 6 and 9 or the lubricating fluid composition as defined in any one of claims 1 to 8 in a heat transfer fluid for direct or indirect cooling system of computers, servers, data center device, transformers, capacitors, or electric vehicles powertrain, wherein the direct or indirect cooling system is selected from axles, differentials, transmissions, electric motors, fluid-filled power cables, battery pack or power electronics.11 . Use of the lubricating fluid composition as defined in any one of claims to 1 to 8 or the ester as defined in any one of claims 1 , 5, 6 and 9 in a gear box and / or electric devices to improve efficiency of said gear box and / or electric devices.

12. A method of improving efficiency of gear box and / or electric devices in a cooling system of data center or an electric vehicle, the method comprising using the lubricating fluid composition as defined in any one of claims 1 to 8 or the ester as defined in any one of claims 1 , 5, 6 and 9 in the electronic powertrain or cooling system of data center.

13. A method of reducing friction between two or more metal parts of an engine, a gearbox or pump of an automobile, a wind turbine, or a hydraulic system, the method comprising using the lubricating fluid composition as defined in any one of claims 1 to 8 in the engine, the gearbox or pump of an automobile, the wind turbine, or the hydraulic system.202400078 Foreign Filing 3014. A method of enhancing the heat transfer in a battery system or an electrical equipment system, the method comprising using the lubricating fluid composition as defined in any one of claims 1 to 8 or the ester as defined in any one of claims 1 , 5, 6 and 9 or in the battery system or the electrical equipment system.

15. A method of lowering the pour point of a lubricating fluid composition by adding the ester as defined in any one of claims 1 , 5, 6 and 9, to said lubricating fluid composition.

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