Use of compositions as friction coefficient reducing agents in oil-based lubricating compositions for clutchless engines and transmissions and novel synergistic compositions

Abstract

The invention relates to the use of a composition comprising a polymer P obtained by free-radical copolymerization of a mixture of (i) at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom, as a friction coefficient reducing agent in an oil-based lubricating composition for engines and transmissions without clutches; (ii) at least one monomer M1, which is a C1-C10 alkyl acrylate or a C1-C10 alkyl methacrylate; and (iii) at least one monomer M2, which is a C11 to C30 alkyl acrylate or a C11 to C30 alkyl methacrylate.

Description

[0001] This application claims priority to application No. SN 63 / 483990 filed in the United States on February 9, 2023, application No. 23160107.1 filed in Europe on March 6, 2023, and application No. 23201073.6 filed in Europe on September 29, 2023, the entire contents of each of which are incorporated by reference into this application for all purposes.

[0002] The present invention relates to the field of lubricating compositions for use in clutchless engines and transmissions, such as gears, and in particular to the need for compositions having a low coefficient of friction in such applications. The invention relates specifically to the use of compositions comprising specific polymers, advantageously in combination with friction modifiers, for reducing the coefficient of friction of oil-based lubricating compositions for clutchless engines and transmissions. Background Art

[0003] In several mechanical fields (automotive or industrial applications), and in particular where metal parts come into repeated contact, it is necessary to reduce friction at the surface and limit the wear of said metal parts, notably by using lubricating compositions. In the field of lubricating compositions, we can distinguish two different applications. The first is those aiming for a low coefficient of friction, which is typically the case for lubricating compositions for engines and transmissions without clutches. The second, on the other hand, is those requiring a high coefficient of friction, as in power transmissions containing clutches.

[0004] Depending on the target application and the desired effect, several additives are included in lubricating compositions that essentially contain base oil.

[0005] In order to achieve high coefficients of friction (higher than 0.1) in applications requiring such behavior, several compounds, in particular polymers, are described, notably in US 2006 / 105924.

[0006] In order to reduce the coefficient of friction of lubricating compositions (below 0.1), it is generally known to use certain friction modifiers.

[0007] Traditional friction modifiers are:

[0008] - Organic friction modifiers (OFMs), which include partial esters and fatty amides, such as glyceryl monooleate and oleamide. OFMs typically have a polar head group that enables the OFM to adsorb onto metal surfaces, and a non-polar hydrocarbon backbone that is required to maintain oil solubility and enable film formation between contacting surfaces.

[0009] Inorganic friction modifiers (IFMs) contain inorganic elements such as sulfur, phosphorus, and molybdenum. Inorganic IFMs chemically decompose to form products that can be chemisorbed or physically adsorbed onto metal surfaces, forming low-shear strength films. An example of an inorganic friction modifier widely used in Japanese engine oils is molybdenum dithiocarbamate (MoDTC).

[0010] Some patents propose reducing the friction coefficient by combining different friction modifiers: US 2013 / 0274158, US 2013 / 0244915 and FR 3014898.

[0011] However, it is known to those skilled in the art that the use of friction modifiers, in particular organic molybdenum compounds containing dithiocarbamate groups, can lead to an exacerbation of wear phenomena in mechanical parts. Therefore, to overcome this problem, anti-wear compounds can be added.

[0012] Standard antiwear agents are based on SAPS (sulfated ash, phosphorus, sulfur) technology like ZDDP (zinc dialkyl dithiophosphate) or on phosphorus chemistry (typically phosphates or phosphites). Both technologies provide ash, sulfur and / or high levels of phosphorus content.

[0013] ZDDP has good performance, but for environmental reasons, the use of anti-wear materials containing metals, sulfur and phosphorus needs to be reduced because:

[0014] -Metals are harmful to lubricants because they produce ash when burned and accumulate deposits on the surface. Varnish and deposits are harmful to mechanical equipment, affecting its durability, and are especially so in electric vehicle powertrain units, where good thermal conductivity is required.

[0015] - Sulfur can cause corrosion, especially on copper, which is used in alloys in engines and, due to the presence of electrical wiring, is widely used in electric vehicle drive train units.

[0016] -Used in engine oils, sulfur and phosphorus can poison the activity of catalysts present in catalytic converters, causing them to become inactivated.

[0017] To overcome these issues, polymeric antiwear agents (AWs) have been developed, as described, for example, in WO 2016 / 177839. Polymer AWs offer the advantages of being ashless (metal-free), sulfur-free, and having very low phosphorus levels (typically approximately 0.34% compared to 8% in ZDDP). This document describes the use of these polymeric antiwear agents in naphthenic oils, but there are some limitations regarding their solubility in other base oils used in clutchless engines and transmissions.

[0018] Polymers, particularly those based on acrylate monomers, have also been described as viscosity index improvers in lubricating compositions, a function that is very different and unrelated to anti-wear properties.

[0019] In this context, there is still a need to develop new environmentally friendly solutions with good performance in reducing friction in lubricating compositions for engines and transmissions without clutches and protecting metal parts in repeated contact from wear. Furthermore, the solutions found should be readily soluble in the common base oils used in engines and transmissions without clutches. Summary of the Invention

[0020] While conducting research to solve the above technical problem, the inventors have surprisingly found that a composition comprising at least one polymer P obtained by free radical copolymerization of a mixture comprising:

[0021] - at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom;

[0022] - at least one monomer M1 which is an acrylic acid C1-C 10 Alkyl ester or methacrylate C1-C 10 alkyl esters; and

[0023] - at least one monomer M2 which is acrylic acid C 11 -C 30 Alkyl ester or methacrylate C 11 -C 30 Alkyl esters.

[0024] The composition is also a good anti-wear agent.

[0025] A first object of the present invention is therefore the use of a composition comprising at least one polymer P as a friction coefficient reducer, preferably simultaneously as an antiwear agent and a friction coefficient reducer, in oil-based lubricating compositions for engines and transmissions without clutches, said at least one polymer being obtained by free-radical copolymerization of a mixture comprising:

[0026] - at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom;

[0027] - at least one monomer M1 which is a C1-C10 alkyl acrylate or a C1-C10 alkyl methacrylate; and

[0028] at least one monomer M2 which is a C11-C30 alkyl acrylate or a C11-C30 alkyl methacrylate.

[0029] Furthermore, the inventors have discovered that combining the above polymer P with a friction modifier promotes the effect of reducing the friction coefficient of an oil-based lubricating composition for an engine. Therefore, as a second object of the present invention, the present invention is directed to a synergistic composition comprising:

[0030] at least one polymer P obtained by free-radical copolymerization of a mixture comprising:

[0031] - at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom;

[0032] - at least one monomer M1 which is an acrylic acid C1-C 10 Alkyl ester or methacrylate C1-C 10 alkyl esters; and

[0033] - at least one monomer M2 which is acrylic acid C 11 -C 30 Alkyl ester or methacrylate C 11 -C 30 alkyl esters; and

[0034] At least one friction modifier FM selected from the group consisting of organic molybdenum friction modifiers such as molybdenum dialkyldithiocarbamates and molybdenum dialkyldithiophosphates, and organic friction modifiers such as glycerides, fatty amides and fatty amines, preferably molybdenum dithiocarbamates and glycerol monooleate.

[0035] A third object of the present invention is a synergistic oil-based lubricant composition for an engine, comprising:

[0036] ●At least one base oil and

[0037] • A synergistic composition as defined above.

[0038] In the above compositions and synergistic compositions, the polymer is preferably a polymer P obtained by free radical copolymerization of a mixture comprising:

[0039] - at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom;

[0040] - at least one monomer M1 which is a C1-C10 alkyl acrylate or a C1-C10 alkyl methacrylate; and

[0041] at least one monomer M2′ which is a C11-C30 alkyl acrylate, and at least one monomer M2″ which is a C11-C30 alkyl methacrylate.

[0042] A fourth object of the present invention is therefore a polymer P obtained by free-radical copolymerization of a mixture comprising:

[0043] - at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom;

[0044] - at least one monomer M1 which is a C1-C10 alkyl acrylate or a C1-C10 alkyl methacrylate; and

[0045] at least one monomer M2′ which is a C11-C30 alkyl acrylate, and at least one monomer M2″ which is a C11-C30 alkyl methacrylate.

[0046] The polymer is advantageously obtained by free-radical copolymerization of a mixture consisting essentially of monomers P1, M1, M2′ and M2″.

[0047] The polymer P is most advantageously obtained by free-radical copolymerization of a mixture consisting essentially of:

[0048] - vinylphosphonic acid;

[0049] -2-ethylhexyl acrylate;

[0050] - dodecyl acrylate and

[0051] - dodecyl methacrylate.

[0052] definition

[0053] Before describing the problem of the present invention in detail, the following should be considered:

[0054] As used herein, the singular forms "a," "an," and "the" include both singular and plural referents unless the context clearly dictates otherwise. By way of example, "a compound" means one compound or more than one compound.

[0055] As used herein, the terms "comprising," "comprises," and "consisting of are synonymous with "including," "includes," or "containing," "contains," and are inclusive or open-ended and do not exclude additional, unrecited members, elements, or method steps. It will be understood that the terms "comprising," "comprises," and "consisting of" as used herein encompass the terms "consisting of," "consists," and "consists of."

[0056] Throughout this application, the term "about" is used to indicate that a value includes the standard deviation of error for the device or method being employed to determine the value.

[0057] As used herein, unless otherwise indicated, the term "average" refers to a number mean.

[0058] As used herein, the terms "% by weight", "wt.-%", "weight percent", or "percent by weight", and the terms "% by volume", "vol.-%", "volume percent", or "percent by volume" are used interchangeably.

[0059] Numerical ranges recited by endpoints include all integers and, where appropriate, fractions contained within that range (e.g., 1 to 5 when referring to, for example, the number of elements, may include 1, 2, 3, and 4, and when referring to, for example, a measurement, may also include 1.5, 2, 2.75, and 3.80). Recitation of endpoints also includes the endpoint values ​​themselves (e.g., 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all subranges contained therein.

[0060] The term "alkyl" refers to a straight or branched monovalent hydrocarbon radical having a specified number of carbon atoms. The alkyl radical may be unsubstituted or substituted with a substituent that does not interfere with the specified function of the composition, and may be substituted once or twice with the same or different groups. Substituents may include, for example, alkoxy, hydroxyl, sulfhydryl, amino, alkyl-substituted amino, nitro, carboxyl, carbonyl, carbonyloxy, cyano, methylsulfonylamino, or halogen. Examples of "alkyl" include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, 3-methylpentyl, etc.

[0061] As used herein, the term "alkenyl" is defined identically to "alkyl," except that it contains at least one carbon-carbon double bond and, notably, has 2 to 30 carbon atoms, e.g., 2 to 20 carbon atoms, or 2 to 10 carbon atoms. Specific alkenyl groups contemplated include ethenyl, 1-propenyl, 2-propenyl, and butenyl. Unless otherwise indicated, an alkenyl group may be unsubstituted or substituted.

[0062] As used herein, the term "alkynyl" is defined identically to "alkyl," except that it contains at least one carbon-carbon triple bond and, notably, has 2 to 30 carbon atoms, e.g., 2 to 20 carbon atoms, or 2 to 10 carbon atoms. Specifically contemplated alkynyl groups include ethynyl, 1-propynyl, 2-propynyl, and butynyl. Unless otherwise indicated, an alkynyl group may be unsubstituted or substituted.

[0063] As used herein, the term "acrylate" corresponds to the salts, esters, and conjugate bases of acrylic acid. The acrylate ion is the anion CH2=CH-COO-. DETAILED DESCRIPTION

[0064] Polymer P

[0065] Advantageously, the monomers P1 of the polymer P used in the present invention are chosen from the group consisting of phosphonic acid monomers, phosphoric acid monomers, dioxaphospholane monomers, phosphonic acid (meth)acrylate and (meth)acrylamide monomers, phosphoric acid (meth)acrylate and (meth)acrylamide monomers, and monomers containing 2 phosphorus atoms, like methyl 2-[2,2-bis(diisopropoxyphosphoryl)ethoxy]methacrylate and propyl N,N-tetramethylbis(phosphonate)-2-hydroxybismethylaminomethacrylate.

[0066] The phosphonic acid monomer P1 of the polymer P may be, for example, a compound having the formula (I)

[0067]

[0068] in

[0069] R1=H, C1-C4 alkyl or Group, wherein R=H or C-C4 alkyl, preferably

[0070] Ethyl, (tert)butyl

[0071] R2=H or C1-C4 alkyl, preferably methyl, ethyl or (iso)propyl

[0072] X = a single bond or a spacer selected from C1-C4 alkyl, ether or ketone, preferably selected from -CH2-, -CH2-CH2-, -CH2-O-CH2-CH2, -CH2-O-CO-CH2-, -CH2-O-(CH2)n-, -O-(CH2)n-, where n = 1 or 2.

[0073] Phosphonic acid monomers that can be used within the framework of the present invention are those having the following formula:

[0074] (IPPA or Isopropenylphosphonic Acid)

[0075] (VPA or vinylphosphonic acid).

[0076] Still other phosphonic acid monomers that can be used within the framework of the present invention are diallylaminophosphonic acid and its esters / salts, preferably diallylaminomethylphosphonic acid and its esters / salts, preferably those having the following formula:

[0077]

[0078] where R 2 As defined above.

[0079] The phosphoric acid monomer P1 of the polymer P may be, for example, a compound having the formula (II)

[0080]

[0081] wherein R1 and R2 are as defined above, and wherein X is a single bond or a spacer selected from C1-C4 alkyl or ether ultimately carrying a hydroxyl group and / or a phosphate group (PO4H2), preferably selected from -CH2-, -CH2-CH2-, -O-(CH2)4-, -O-CH2-CHOH-CH2-, -CH2-O-CH2-CHOH-CH2-, -O-CH2-C(PO4H2)-CH2-, -CH2-O-CH2-C(PO4H2)-CH2-.

[0082] The dioxaphospholane monomer P1 of the polymer P may be, for example, a compound of formula (III):

[0083]

[0084] wherein X is a spacer selected from C1-C4 ethers, preferably selected from -O-CH2 or -CH2-O-CH2.

[0085] The phosphonic acid (meth)acrylate and (meth)acrylamide monomers P1 of the polymer P may be, for example, compounds having the formula (IV)

[0086]

[0087] wherein R1=H or CH3, X=-O-, -NH- or -N(CH3)-, R2 is as defined above, and Y is a spacer selected from a C1-C10 alkyl group or an ether or thioether ultimately bearing a hydroxyl group and / or a phenyl (Ph) group, preferably -CH2-CH2-, -C(CH3)2-CH2-CH2-CH2-, -(CH2-CH2)3-O-CH2-CH2-, -CH2-CHOH-CH2-O-CO-CH2-, -CH2-Ph-CH2-, CH2-CHOH-CH2-S-Ph-, CH2-CHOH-CH2-O-Ph-.

[0088] The (meth)acrylate phosphate and (meth)acrylamide monomers P1 of the polymer P may be, for example, compounds having formula (V)

[0089]

[0090] wherein R1=H or CH3, X=-O-, -NH- or -N(CH3)-, R2 is as defined above, and Y is a spacer selected from C1-C10 alkyl or alkylene oxide units, preferably ethylene oxide and / or propylene oxide units, -CH2-CH2-.

[0091] Phospho(meth)acrylate and (meth)acrylamide-based monomers that have been tested within the framework of the present invention are those having the following formula:

[0092]

[0093] Where n is 3 to 7

[0094]

[0095] where p is 1 to 2

[0096]

[0097] wherein n is 3 to 9.

[0098] We can also consider PO / EO monomers containing P, like those with the following formula:

[0099]

[0100] wherein m+n is at most equal to 15, preferably 10; and when n=0:

[0101] m=1-5, preferably 1-3; and when n>0: n≥m+2.

[0102] Preferably, monomer P1 of polymer P is vinylphosphonic acid (VPA).

[0103] Advantageously, the monomer M1 of the polymer P used in the present invention is chosen from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, n-heptyl (meth)acrylate, isoheptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, preferably 2-ethylhexyl (meth)acrylate.

[0104] As for the monomer M2, it is advantageously selected from the group consisting of n-undecyl(meth)acrylate, iso-undecyl(meth)acrylate, iso-dodecyl(meth)acrylate, n-tridecyl(meth)acrylate, n-tetradecyl(meth)acrylate, n-pentadecyl(meth)acrylate, n-hexadecyl(meth)acrylate, n-heptadecyl(meth)acrylate, n-octadecyl(meth)acrylate, n-nonadecyl(meth)acrylate, dodecyl(meth)acrylate, n-eicosyl(meth)acrylate and n-tricosyl(meth)acrylate, preferably dodecyl(meth)acrylate and dodecyl(meth)acrylate.

[0105] In a preferred embodiment, the polymer P comprises at least one monomer M2′ which is a C11-C30 alkyl acrylate and at least one monomer M2″ which is a C11-C30 alkyl methacrylate, more preferably dodecyl acrylate and dodecyl methacrylate.

[0106] In a preferred embodiment, the polymer P is obtained by free radical copolymerization of a mixture consisting essentially of:

[0107] - vinylphosphonic acid;

[0108] -2-ethylhexyl acrylate;

[0109] - dodecyl acrylate and

[0110] - dodecyl methacrylate.

[0111] More preferably, the polymer P is obtained by free-radical copolymerization of a mixture having the following molar ratios, based on the total amount of vinylphosphonic acid, 2-ethylhexyl acrylate, dodecyl acrylate and dodecyl methacrylate:

[0112] - vinylphosphonic acid: 1% to 20%, notably 2% to 15%, preferably 5% to 10%;

[0113] - 2-ethylhexyl acrylate: 10% to 90%, notably 20% to 80%, preferably 30% to 60%;

[0114] - lauryl acrylate: 10% to 70%, notably 15% to 50% and more preferably 20% to 40%;

[0115] - Lauryl methacrylate: 10% to 70%, notably 15% to 50% and more preferably 20% to 40%.

[0116] Even more preferably, the polymer P is obtained by free-radical copolymerization of a mixture having the following molar ratios, based on the total amount of vinylphosphonic acid, 2-ethylhexyl acrylate, dodecyl acrylate and dodecyl methacrylate:

[0117] - vinylphosphonic acid: 1% to 20%, notably 2% to 15%, preferably 5% to 10%;

[0118] - 2-ethylhexyl acrylate: 30% to 60%;

[0119] - dodecyl acrylate: 15% to 50%, preferably 20% to 40%;

[0120] - Dodecyl methacrylate: 15% to 50%, preferably 20% to 40%.

[0121] Composition

[0122] According to a preferred embodiment, the use according to the invention is such that the composition further comprises at least one friction modifier FM selected from the group consisting of organic molybdenum friction modifiers such as molybdenum dialkyldithiocarbamates and molybdenum dialkyldithiophosphates, and organic friction modifiers such as glycerides, fatty amides and fatty amines, preferably molybdenum dithiocarbamates and glycerol monooleate. Indeed, as shown in the experimental section below, when at least one FM as described above is combined with the composition according to the invention, the effect on the reduction of the friction coefficient is enhanced.

[0123] Advantageously, the composition comprises from 0.1% to 10% by weight, preferably from 0.5% to 2.5% by weight, of a friction modifier FM as described above, based on the total weight of the composition.

[0124] According to a preferred embodiment, the oil-based lubricating composition in which the composition according to the invention is used comprises a base oil selected from the group consisting of mineral oils, synthetic oils and natural oils.

[0125] Mineral oils are known per se and are commercially available. They are generally obtained from mineral oil or crude oil by distillation and / or refining, and optionally further purification and refining processes. The term mineral oil particularly includes higher-boiling fractions of crude oil or mineral oil. Typically, the boiling point of mineral oil is above 200° C., preferably above 300° C., at 5000 Pa. Production is also possible by low-temperature retorting of shale oil, coking of bituminous coal, distillation of lignite under air exclusion, and hydrogenation of bituminous coal or lignite. Therefore, mineral oils have varying proportions of aromatic hydrocarbons, cyclic hydrocarbons, branched hydrocarbons, and straight-chain hydrocarbons, depending on their source.

[0126] Synthetic oils include organic esters such as diesters and polyesters, polyalkylene glycols, polyethers, synthetic hydrocarbons, and in particular polyolefins, with polyalphaolefins (PAOs) being preferred, silicone oils, and perfluoroalkyl ethers. In addition, synthetic base oils derived from gas-to-liquids (GTL), coal-to-liquids (CTL), or biomass-to-liquids (BTL) processes can be used. These are generally slightly more expensive than mineral oils, but offer advantages in terms of performance.

[0127] Natural oils are animal or vegetable oils, such as neatsfoot oil or jojoba oil.

[0128] According to the API (American Petroleum Institute), base oils used in lubricant formulations are divided into several groups. Mineral oils are divided into Group I (non-hydrogenated), and based on saturation, sulfur content and viscosity index, they are divided into Group II and Group III (both hydrogenated). PAOs correspond to Group IV. All other base oils are included in Group V.

[0129] These base oils useful in the present invention may also be used as mixtures and are in many cases commercially available.

[0130] According to a preferred embodiment, the base oil is a mineral oil or a synthetic base oil of Group II or III, notably a Group IV synthetic base oil, or a mixture thereof.

[0131] Friction reduction effect

[0132] According to the use according to the invention, the coefficient of friction of an oil-based lubricant composition is reduced between 40°C and 150°C to an absolute value of less than 0.2 measured using the HFRR (High Frequency Reciprocating Rig) tribological test according to ASTM D6079, except that the diesel fuel has been replaced by the oil-based lubricant composition and the constant time and temperature of 60°C for 75 minutes has been replaced by a warm-up phase at 40°C for 15 minutes and a ramp-up phase at 2°C / min up to 150°C for 55 minutes.

[0133] Preferably, the coefficient of friction of the oil-based lubricant composition is reduced by 0.12 points as measured using the HFRR (High Frequency Reciprocating Rig) tribology test according to ASTM D6079 between 70°C and 150°C, compared to an oil-based lubricant composition consisting of base oil alone, except that the diesel fuel has been replaced by the oil-based lubricant composition, and the constant time and temperature of 60°C for 75 minutes has been replaced by a warm-up phase at 40°C for 15 minutes and a ramp-up phase at 2°C / min up to 150°C for 55 minutes.

[0134] Synergistic composition

[0135] A second object of the present invention is a synergistic composition comprising:

[0136] at least one polymer P obtained by free-radical copolymerization of a mixture comprising:

[0137] - at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom;

[0138] - at least one monomer M1 which is an acrylic acid C1-C 10 Alkyl ester or methacrylate C1-C 10 alkyl esters; and

[0139] - at least one monomer M2 which is acrylic acid C 11 -C 30 Alkyl ester or methacrylate C 11 -C 30 alkyl esters; and

[0140] At least one friction modifier FM selected from the group consisting of organic molybdenum friction modifiers such as molybdenum dialkyldithiocarbamates and molybdenum dialkyldithiophosphates, and organic friction modifiers such as glycerides, fatty amides and fatty amines, preferably molybdenum dithiocarbamates and glycerol monooleate.

[0141] In the synergistic composition, the preferred organic molybdenum friction modifiers are, in fact, molybdenum dialkyldithiocarbamates and molybdenum dialkyldithiophosphates, and the preferred organic friction modifiers are, in fact, glycerides, fatty amides, and fatty amines.

[0142] The synergistic composition preferably consists essentially of at least one polymer P obtained by free-radical copolymerization of a mixture consisting essentially of:

[0143] - at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom;

[0144] - at least one monomer M1 which is an acrylic acid C1-C 10Alkyl ester or methacrylate C1-C 10 alkyl esters; and

[0145] - at least one monomer M2 which is acrylic acid C 11 -C 30 Alkyl ester or methacrylate C 11 -C 30 alkyl esters;

[0146] and at least one friction modifier FM selected from the group consisting of molybdenum dithiocarbamate and glyceryl monooleate.

[0147] Preferably, the polymer P comprises at least one monomer M2' and at least one monomer M2" as defined above.

[0148] In the synergistic composition according to the invention, the polymer P is advantageously obtained by free-radical copolymerization of a mixture consisting essentially of:

[0149] - vinylphosphonic acid;

[0150] -2-ethylhexyl acrylate;

[0151] - dodecyl acrylate and

[0152] - dodecyl methacrylate.

[0153] In a preferred embodiment, the polymer P is obtained by free-radical copolymerization of a mixture having the following molar ratios, based on the total amount of vinylphosphonic acid, 2-ethylhexyl acrylate, dodecyl acrylate and dodecyl methacrylate:

[0154] - vinylphosphonic acid: 1% to 20%, notably 2% to 15%, preferably 5% to 10%;

[0155] - 2-ethylhexyl acrylate: 10% to 90%, notably 20% to 80%, preferably 30% to 60%;

[0156] - lauryl acrylate: 10% to 70%, notably 15% to 50% and more preferably 20% to 40%;

[0157] - Lauryl methacrylate: 10% to 70%, notably 15% to 50% and more preferably 20% to 40%.

[0158] Even more preferably, the polymer P is obtained by free-radical copolymerization of a mixture having the following molar ratios, based on the total amount of vinylphosphonic acid, 2-ethylhexyl acrylate, dodecyl acrylate and dodecyl methacrylate:

[0159] - vinylphosphonic acid: 1% to 20%, notably 2% to 15%, preferably 5% to 10%;

[0160] - 2-ethylhexyl acrylate: 30% to 60%;

[0161] - dodecyl acrylate: 15% to 50%, preferably 20% to 40%;

[0162] - Dodecyl methacrylate: 15% to 50%, preferably 20% to 40%.

[0163] In an advantageous embodiment of the synergistic composition according to the invention, the composition comprises from 0.1% to 10% by weight, preferably from 0.5% to 2.5% by weight, of at least one friction modifier FM, based on the total weight of the composition.

[0164] The most impressive results were obtained with the synergistic composition according to the invention, wherein the friction modifier was glyceryl monooleate (GMO). The effect on reducing the coefficient of friction was unexpectedly high.

[0165] Synergistic oil-based lubricant composition

[0166] A third object of the present invention is a synergistic oil-based lubricant composition for clutchless engines and transmissions, the composition comprising:

[0167] ●At least one base oil and

[0168] • A synergistic composition as previously defined.

[0169] In a preferred embodiment, the synergistic lubricating oil composition for clutchless engines and transmissions according to the present invention is such that the base oil is a Group II or III mineral oil or a synthetic base oil, notably a Group IV synthetic base oil, or a mixture thereof.

[0170] According to the present invention, the concentration of polymer P in the oil-based lubricant composition is preferably in the range of 0.01 to 10% by weight, more preferably in the range of 0.1 to 5% by weight and most preferably in the range of 0.5 to 2.5% by weight, based on the total weight of the oil-based lubricant composition.

[0171] The composition comprising the polymer P according to the invention can be mixed with one or more base oils.

[0172] The compositions comprising the polymers P according to the invention can be added to fresh and / or aged oils. Furthermore, the compositions comprising the polymers P according to the invention can be added directly to clutch-free engine and transmission oils or indirectly by diluting with a diesel mixture comprising the polymers.

[0173] In addition to the composition comprising the polymer P according to the invention, the oil-based lubricant composition may also contain further additives. These additives include viscosity index improvers, pour point improvers and DI additives (dispersants, detergents, defoamers, corrosion inhibitors, antioxidants, other anti-wear and extreme pressure additives, other friction modifiers).

[0174] Additional useful VI improvers include poly(iso)butylene (PIB), fumarate-olefin copolymers, styrene-maleate copolymers, hydrogenated styrene-diene copolymers (HSD) and olefin copolymers (OCP), and polymethacrylates.

[0175] Suitable dispersants include poly(isobutylene) derivatives such as poly(isobutylene) succinimide (PIBSI); polyisobutenyl succinic anhydride (PIBSA), polyisobutenyl succinimide, polyisobutenyl succinates, polyaminomethylalkylphenols (also known as Mannich dispersants).

[0176] Preferred detergents include metal-containing compounds, such as phenoxides; salicylates; thiophosphonates, especially thiopyrophosphonates, thiophosphonates, and phosphonates; sulfonates and carbonates. These compounds may contain, among other metals, calcium, magnesium, and barium. These compounds may preferably be used in neutral or overbased form.

[0177] Of particular interest are additional defoamers, which are often divided into silicone-containing and silicone-free defoamers. Silicone-containing defoamers include linear poly(dimethylsiloxanes) and cyclic poly(dimethylsiloxanes). Silicone-free defoamers that can be used are often polyacrylates and polyethers, such as poly(ethylene glycol) or tributyl phosphate.

[0178] In a particular embodiment, the lubricating oil composition of the present invention may contain corrosion inhibitors. These are often divided into rust inhibitors and metal deactivators / deactivators. The rust inhibitors used may be, in particular, sulfonates, such as petroleum sulfonates or (in many cases overbased) synthetic alkylbenzene sulfonates, such as dinonylnaphthalene sulfonate; carboxylic acid derivatives, such as lanolin (wool fat), paraffin oxides, zinc naphthenates, alkylated succinic acids, 4-nonylphenoxy-acetic acid, amides and imides (N-acylsarcosine, imidazoline derivatives); amine-neutralized mono- and dialkyl phosphates; morpholine, dicyclohexylamine or diethanolamine. Metal deactivators / deactivators include benzotriazole, tolyltriazole, 2-mercaptobenzothiazole, dialkyl-2,5-dimercapto-1,3,4-thiadiazole; N,N'-disalicylideneethylenediamine, N,N'-disalicylidenepropylenediamine; zinc dialkyldithiophosphates and zinc dialkyldithiocarbamates.

[0179] Another preferred group of additives is the group of antioxidants. Antioxidants include, for example, phenols such as 2,6-di-tert-butylphenol (2,6-DTB), butylated hydroxytoluene (BHT), 2,6-di-tert-butyl-4-methylphenol, 4,4'-methylenebis(2,6-di-tert-butylphenol); aromatic amines, in particular alkylated diphenylamines, N-phenyl-1-naphthylamine (PNA), polymeric 2,2,4-trimethyldihydroquinone (TMQ); sulfur and phosphorus containing compounds, such as metal dithiophosphates, such as zinc dithiophosphate (ZnDTP), "OOS triesters", i.e. dithiophosphoric acids with olefins, cyclopentadiene, norbornyl, dihydrogen phosphates, cyclopentadiene ... reaction products of activated double bonds of olefins, alpha-pinene, polybutene, acrylates, maleates (ashless on combustion); organic sulfur compounds, for example dialkyl sulfides, diaryl sulfides, polysulfides, modified mercaptans, thiophene derivatives, xanthates, thioglycols, thioaldehydes, sulfur-containing carboxylic acids; heterocyclic sulfur / nitrogen compounds, in particular dialkyldimercaptothiadiazoles, 2-mercaptobenzimidazoles; zinc and methylenebis(dialkyldithiocarbamates); organic phosphorus compounds, for example triaryl and trialkyl phosphites; organic copper compounds and overbased calcium- and magnesium-based phenates and salicylates.

[0180] Other potential preferred anti-wear (AW) and extreme pressure (EP) additives include phosphorus compounds such as trialkyl phosphates, triaryl phosphates, such as tricresyl phosphate, amine-neutralized mono- and dialkyl phosphates, ethoxylated mono- and dialkyl phosphates, phosphites, phosphonates, phosphines; compounds containing sulfur and phosphorus, such as metal dithiophosphates, such as zinc dialkyl dithiophosphate (ZnDTP), ammonium dialkyl dithiophosphate, antimony dialkyl dithiophosphate, molybdenum dialkyl dithiophosphate, lead dialkyl dithiophosphate, "OO "S triesters" = reaction products of dithiophosphoric acids with activated double bonds from olefins, cyclopentadiene, norbornadiene, α-pinene, polybutene, acrylates, maleates, triphenylphosphorothioate (TPPT); compounds containing sulfur and nitrogen, for example zinc bis(pentyldithiocarbamate) or methylenebis(di-n-butyldithiocarbamate); sulfur compounds containing elemental sulfur and H-S-sulfurized hydrocarbons (diisobutylene, terpenes); sulfurized glycerides and fatty acid esters; overbased sulfonates; chlorine compounds or solids, such as graphite or molybdenum disulfide.

[0181] More preferably, if any, the other anti-wear additives and / or extreme pressure additives are selected from phosphorus compounds, compounds comprising sulfur and phosphorus, compounds comprising sulfur and nitrogen, sulfur compounds comprising elemental sulfur and H~S-sulfurized hydrocarbons, sulfurized glycerides and fatty acid esters, overbased sulfonates, chlorine compounds, graphite or molybdenum disulphide.

[0182] Another preferred additive group is the group of additional friction modifiers. The additional friction modifiers used may include mechanically active compounds such as molybdenum disulfide, graphite (including fluorinated graphite), poly(trifluoroethylene), polyamides, polyimides; compounds that form an adsorption layer such as long-chain carboxylic acids, fatty acid esters, ethers, alcohols, amines, amides, imides; compounds that form a layer by tribochemical reaction such as saturated fatty acids, phosphoric acid and thiophosphates, xanthates, sulfonated fatty acids; compounds that form a polymeric layer such as ethoxylated partial esters of dicarboxylic acids, dialkyl phthalates, methacrylates, unsaturated fatty acids, sulfonated olefins or organometallic compounds such as molybdenum compounds (molybdenum dithiophosphates and molybdenum dithiocarbamates MoDTC) and their combinations with ZnDTP and copper-containing organic compounds.

[0183] Some of the additives detailed above may perform multiple functions.

[0184] Lubricants useful in the present invention, particularly for engine oils, may preferably be designed to meet the requirements of the SAE classification as specified in SAE J300. For example, the requirements of viscosity grades 0W, 5W, 10W, 15W, 20W, 25W, 20, 30, 40, 50, and 60 (single grades) and 0W-40, 10W-30, 10W-60, 15W-40, 20W-20, and 20W-50 (multi-grades) may be adjusted.

[0185] The present invention also relates to the use of a composition comprising at least one polymer P as described above as:

[0186] - as polymeric anti-wear agents and friction modifiers in lubricants (including but not limited to engines, transmissions, hydraulic systems); and / or metalworking fluids (including but not limited to forming fluids and removal fluids) and / or greases (including but not limited to bearings, gears, wire ropes); or

[0187] - As adhesion promoters and / or additives for providing corrosion resistance, i.e. in adhesive bonding of two surfaces, for bonding paints or varnishes or inks to metal surfaces, or as additives in coating compositions.

[0188] Polymeric antiwear agents (AW) and their use in lubricant compositions

[0189] In several mechanical sectors (automotive or industrial applications), and in particular where metal parts come into repeated contact, it is necessary to reduce friction at the surfaces and limit the wear of said metal parts, notably through the use of lubricating compositions. Depending on the intended application and the desired effect, some additives (including anti-wear additives) are included in lubricating compositions that essentially contain a base oil.

[0190] Standard antiwear agents are based on SAPS (sulfated ash, phosphorus, sulfur) technology like ZDDP (zinc dialkyl dithiophosphate) or based on phosphorus chemistry (typically phosphates, phosphonates or phosphites). Both technologies provide ash, sulfur

[0191] In order to overcome the problems of SAPS, polymeric antiwear agents (AW) have been developed. Polymer AW has the advantages of being ashless (metal-free), sulfur-free and having very low P levels.

[0192] The polymeric antiwear compositions developed typically present compositions comprising at least one polymer P as described above.

[0193] By combining the polymer AW with a friction modifier, it is possible to promote the effect of reducing the friction coefficient of the oil-based lubricating composition.

[0194] Polymer AW can be used in lubricants for any type of application requiring an AW additive, such as in industrial or automotive applications, including but not limited to lubricants for industrial use (e.g., hydraulic fluids, compressor fluids, refrigeration oils, turbine and circulating oils, gear oils, other gear industry oils, industrial engine oils, metalworking fluids, and greases) and / or automotive lubricants (e.g., engine oils, transmission fluids, coolants, and greases).

[0195] Use as an adhesion promoter and / or additive to provide corrosion resistance

[0196] The polymers P described above can also be used as adhesion promoters in several applications listed below.

[0197] In a first embodiment, the copolymer can be used for adhesive bonding of two surfaces S1 and S2, preferably metal surfaces, to each other. The idea is to use the copolymer as an additive in a surface treatment composition for all or part of the (preferably metal) surface (S1) and optionally all or part of the (preferably metal) surface (S2) and / or in an adhesive layer between the two surfaces. In this method, the surface treatment composition can be:

[0198] - conversion composition; and / or

[0199] - a solution or dispersion which is applied to the surface to be treated after the conversion coating has been applied to the surface.

[0200] In a second embodiment, the polymer P may be used in a method of bonding a paint or varnish or ink to a metal surface (S1), the method comprising:

[0201] - treating all or part of said metal surface (S1) with a composition comprising the copolymer; and

[0202] - Applying a paint or varnish or ink to the treated surface (S1).

[0203] In the third embodiment, polymer P can be used as the additive in coating composition, and coating composition includes but not limited to ink and paint, as solvent-based and powder coating.This means that copolymer can be mixed in ink and paint (comprising for example solvent-based paint and powder coating) as additive, and it promotes the adhesion of ink / painting and base material and / or the adhesion of another coating on ink / painting.Especially, copolymer can be used for pre-coated metal (PCM) application, i.e. pre-coated (painted) metal coil, as the coil used for building application.Idea is that copolymer is introduced in painting to improve the adhesion of painting and base material, particularly when the coil of painting is cut into sheet and then is transformed into corrugated metal sheet etc., improve " formability ", paint still must continue to adhere to metal sheet perfectly simultaneously.Another advantage of this embodiment is the paint adhesion and the corrosion resistance improved during storage (for example under wet conditions).

[0204] Should the disclosure of any patents, patent applications, and publications incorporated herein by reference conflict with the description of the present application to the extent that a term may be unclear, the description of the present application shall take precedence. BRIEF DESCRIPTION OF THE DRAWINGS

[0205] Figure 1 、 Figure 2 and Figure 3 is a graph of the coefficient of friction as a function of temperature for the lubricating compositions prepared in the following experimental section.

[0206] Experimental part

[0207] Raw materials used

[0208]

[0209]

[0210] Table 1. Commercial index numbers of raw materials used

[0211] Preparation of polymer P according to the invention: The copolymer poly(vinylphosphonic acid-co-2-ethylhexyl acrylate-co-dodecyl acrylate-co-dodecyl methacrylate) (poly(VPA-co-2-EHA-co-LA-co-LMA)) (7.5 / 46.5 / 23 / 23 mol %) was synthesized by conventional free radical polymerization in ethyl acetate (EtOAc) (initiator: 2,2′-azobis-2-methylbutyronitrile, AMBN)

[0212] In a 2.5 L jacketed reactor equipped with a multi-stage lighting A320 stirring blade, a reverse blade, a condenser connected to a microcooler, and a cryostat, 31.02 g (0.230 mol) of VPA (80% purity), 40.17 g (0.214 mol) of 2-EHA (98% purity), 28.22 g (0.106 mol) of LA (90% purity), 28.00 g (0.106 mol) of LMA (96% purity), and 394.38 g of ethyl acetate were added. The reaction mixture was degassed by bubbling nitrogen with stirring while the cryostat was set to 70° C. over a 1 hour temperature ramp. Once a temperature of 70° C. is reached, a nitrogen stream is left in the air and a 65 wt % (meth)acrylate solution of three comonomers, 2-EHA (227.61 g, 1.210 mol), LA (159.91 g, 0.599 mol) and LMA (158.66 g, 0.599 mol) in ethyl acetate (252.73 g) is introduced under stirring by a syringe pump over a period of 9 hours. The reaction is started by adding 34.19 g of an 8 wt % AMBN solution (2.78 g, 0.0142 mol, 98% purity) in ethyl acetate (31.42 g) at one time. After a 3-hour reaction, a 12.3 wt % AMBN solution (5.64 g, 0.029 mol, 98% purity) of 45.11 g in ethyl acetate (39.47 g) is introduced over a period of 6 hours by a syringe pump. Once the initiator and monomer feeds were complete, the reaction mixture was aged at 70°C for an additional 11 hours before being cooled to ambient temperature and discharged. 1 H NMR analysis was performed in CDCl3. The final conversions in 2-EHA, LA, and LMA were greater than 99%. The final conversion in VPA was approximately 74%. Molecular weights were determined by size exclusion chromatography (SEC) in conjunction with RI and multi-angle light scattering (MALLS) detectors. n,SEC-MALLS =45,000 g·mol -1 ;M w,SEC-MALLS =101,000 g·mol -1 ; The product was then transferred into EHC45 base oil and the ethyl acetate was removed using a rotary evaporator at 50° C. under reduced pressure (40 mbar). The final solids content was 33.3 wt %.

[0213] Methods used to measure molecular weight :

[0214] Size-spacing chromatography (SEC) samples were diluted in mobile phase (THF + 0.01 M tetrabutylammonium tetrafluoroborate + 100 μL trifluoroacetic acid / kg eluent) and filtered (on 0.45 μm pores) prior to analysis.

[0215] Samples were analyzed by SEC equipped with a multi-angle laser light scattering (MALLS) detector according to the following conditions:

[0216] ●Eluent: THF + 0.01M tetrabutylammonium tetrafluoroborate + 100μL trifluoroacetic acid / kg eluent

[0217] Flow rate: 1 mL / min -1

[0218] Column: Agilent Polypore (2*30cm) + guard column

[0219] ●Detection: RI (Agilent detector) + MALLS Mini Dawn TREOS

[0220] ●Sample concentration: 3 mg·mL in mobile phase -1

[0221] Injection volume: 100 μL

[0222] The copolymer poly(2-(phosphonooxy)ethyl methacrylate-co-2-ethylhexyl acrylate-co-dodecyl acrylate-co-dodecyl methacrylate) (poly( PAM4000-co-2-EHA-co-LA-co-LMA))(8 / 46 / 23 / 23 mol%)

[0223] In a 2.5 L jacketed reactor equipped with a multi-stage illuminated A320 stirring blade, reverse blade, condenser connected to a microcooler and a cryostat bath, 3.39 g (0.012 mol) of 74.9 wt% PEG in EtOH was added. The mixture was stirred at 40 ℃ for 1 h and then degassed with 12.81 g (0.069 mol) of 2-EHA (99% purity), 11.26 g (0.042 mol) of LA (90% purity), 11.17 g (0.044 mol) of LMA (96% purity), 7.71 g (0.040 mol) of AMBN (98% purity) and 395.38 g of ethyl acetate. The reaction mixture was degassed under stirring by bubbling nitrogen while the temperature of the low-temperature constant-temperature bath was set to reach 70 ℃ in a 1 hour temperature ramp. Once a temperature of 70 ℃ was reached, nitrogen gas was left in the air and two separate monomer solutions were introduced in parallel over 6 hours by a syringe pump under stirring. The first is a mixture of three monomers 2-EHA, LA and LMA: 690.56 g of a solution containing 2-EHA (237.70 g, 1.289 mol), LA (158.28 g, 0.658 mol), LMA (167.52 g, 0.658 mol) and EtOAc (127.06 g). The second is a 74.9 wt% solution in EtOH. PAM4000 solution (64.47 g, 0.230 mol). Once the monomer feed was complete, the reaction mixture was aged at 70°C for another 4 hours before being cooled to ambient temperature and discharged. Samples were taken and passed through 1 H NMR analysis was performed in CDCl3. The final conversion of 2-EHA and LA was 94%, while that of LMA and The conversion in PAM4000 was >99%. The product was then transferred to EHC45 base oil and the ethyl acetate was removed using a rotary evaporator at 50° C. under reduced pressure (40 mbar). The final solids content was 50 wt%.

[0224] Preparation of other comparative polymers

[0225] Two comparative polymers were prepared based on VPA and 2EHA according to Examples 1 and 2 of WO 2016 / 177839 A1. Those polymers differ from the polymers according to the invention notably in that they do not contain at least one monomer M2 which is a C11-C30 alkyl acrylate or a C11-C30 alkyl methacrylate.

[0226] Those polymers were not tested in the following friction tests because they presented solubility issues in Group II base oils.

[0227] In order to demonstrate the influence of the presence of VPA in the polymer backbone, notably on the anti-wear properties, another comparative polymer has been prepared. This comparative polymer P' was prepared according to the following method:

[0228] Preparation of polymer P': Copolymer poly(2-ethylhexyl acrylate-co-dodecyl acrylate-co-dodecyl methacrylate) (poly(2-EHA-co-LA-co-LMA)) (49 / 25 / 26 mol%) was synthesized by conventional free radical polymerization in ethyl acetate (EtOAc) (initiator: 2,2'-azobis-2-methylbutyronitrile, AMBN)

[0229] In a 0.75 L jacketed reactor equipped with a MixelTT stirring blade, a reverse blade, a condenser connected to a microcooler and a low-temperature constant temperature bath, 4.80 g (0.026 mol) of 2-EHA (98% purity), 3.13 g (0.013 mol) of LA (90% purity), 2.61 g (0.014 mol) of AMBN (98% purity) and 106.57 g of ethyl acetate were added. The reaction mixture was degassed by bubbling nitrogen under stirring while the temperature of the low-temperature constant temperature bath was set to reach 70° C. within a 1 hour temperature ramp. Once a temperature of 70° C. was reached, the nitrogen flow was left in the air and two different (meth)acrylate solutions were added dropwise; a 60 wt % (meth)acrylate solution of the two comonomers 2-EHA (91.25 g, 0.495 mol) and LA (59.51 g, 0.248 mol) in ethyl acetate (100.5 g) was introduced over 4 hours and a pure LMA (96% purity) solution (69.06 g, 0.261 mol) was introduced over 6 hours by a syringe pump under stirring. Once the monomer feeds were complete, the reaction mixture was aged at 70° C. for a further 10 hours before being cooled to ambient temperature and discharged. Samples were taken and passed through 1 H NMR analysis was performed in CDCl3. Final conversions in 2-EHA, LA, and LMA were greater than 99%. Molecular weights were determined by size exclusion chromatography (SEC) coupled with RI and multi-angle light scattering (MALLS) detection. n,SEC-MALLS =41,000 g·mol -1 ;M w,SEC-MALLS =109,000 g·mol -1 ; The product was then transferred into EHC45 base oil and the ethyl acetate was removed using a rotary evaporator at 50° C. under reduced pressure (40 mbar). The final solids content was 33.3%.

[0230] Lubricating composition

[0231] Preparation: In a 100 mL beaker, 50 g of a formulation containing base oil and other compounds in the proportions described in Table 2 below was prepared. They were mixed at 60° C. using mechanical stirring at 750 rpm for 15 minutes. The resulting composition was bright and transparent, except that the use of MoDTC turned the blend slightly green.

[0232] The formulations were completed in a Group II base oil blend having a kinematic viscosity of 9 cSt at 100°C to simulate a typical engine oil (SAE 20 grade).

[0233] base oil ZDDP Polymer P GMO MoDTC Comparison 1 100 0 0 0 0 Comparison 2 99 1 0 0 0 Contrast 3 99 0 0 1 0 Contrast 4 99 0 0 0 1 Contrast 5 98 1 0 1 0 Contrast 6 98 1 0 0 1 Present invention 1 99 0 1 0 0 Present invention 2 98 0 1 1 0 Present invention 3 98 0 1 0 1

[0234] Table 2. Composition in % by weight

[0235] Friction test:

[0236] Materials: Equipment HFRR (High Frequency Reciprocating Tester): Ball-plate reciprocating friction system from PCS Instruments.

[0237] Method: For each of the compositions prepared above, the coefficient of friction was measured by HFRR: ball on disk: metal / metal under a load of 200 g with a stroke of 1000 microns, at 40° C. for 15 min and then ramped to 150° C. at 2° C. / min for 55 min. The method used was that described in ASTM D6079, except that the diesel fuel was replaced by the formulation presented in Table 3 and the constant time and temperature of 60° C. for 75 min was replaced by a preheating phase (40° C. for 15 min) and a ramping phase (to 150° C. at 2° C. / min for 55 min).

[0238] result:

[0239]

[0240]

[0241] Table 3. Friction reduction results

[0242] The above results have been converted into graphs in order to highlight the differences between the present invention and the comparative examples.

[0243] exist Figure 1In the data presented in Figure 1, it is shown that the polymer according to the invention (Invention 1) is as good as the benchmark ZDDP (Comparative 2) as an antiwear agent for lubricating compositions, since the friction coefficient is reduced along the slope (40°C-150°C) up to an absolute value of less than or equal to 0.17 and is reduced by 37% at 150°C compared to the oil-based lubricant composition comprising no additive (Comparative 1).

[0244] In the results of present invention 2, Figure 2 In the results, we can note that by adding polymer P and GMO as friction modifiers to the oil-based composition (Invention 2), we achieve an unexpected synergistic effect. In fact, the same effect of promoting friction coefficient reduction is not achieved with ZDDP and GMO (Comparative 5). A skilled person would expect intermediate results between Comparative 3 and Invention 1 at 150°C, as is the case with Comparative 5, which is intermediate between Comparative 2 and Comparative 3. Surprisingly, the friction coefficient of Invention 2 is reduced to a level far below that of Comparative 3. This effect is also highlighted in Table 3, which shows that the % friction reduction at 150°C is +22% for Invention 2 (P+GMO) and -21% for Comparative 5 (ZDDP+GMO) compared to an oil-based composition containing GMO but without the antiwear agent AW. It can also be seen that the % friction reduction at 150°C is +45% for Invention 2 (P+GMO) and +16% for Comparative 5 (ZDDP+GMO) compared to an oil-based composition containing the same antiwear agent AW but without GMO.

[0245] In the results of present invention 3 Figure 3 In the data, we can note that by adding polymer P and MoDTC as friction modifiers to the oil-based composition (Invention 3), we also achieve an unexpected synergistic effect. In fact, the same effect of promoting friction coefficient reduction is not achieved with ZDDP and MoDTC (Comparative 6). One would have expected results close to those of Comparative 4 (MoDTC alone) at 150°C, as was the case with Comparative 6. Surprisingly, the friction coefficient of Invention 3 is reduced to significantly less than that of Comparative 4. This effect is also highlighted in Table 3, which shows that the % friction reduction at 150°C is +37% for Invention 3 (P + MoDTC) and -7% for Comparative 6 (ZDDP + MoDTC) compared to an oil-based composition containing MoDTC but without the antiwear agent AW. It can also be seen that the % friction reduction at 150°C is +65% for Invention 3 (P + MoDTC) and +42% for Comparative 6 (ZDDP + MoDTC) compared to an oil-based composition containing the same antiwear agent AW but without MoDTC.

[0246] Wear resistance test:

[0247] Materials and methods:

[0248] - 4-ball wear test: A 4-ball tester was used similarly to the Falex 4-ball tester. Tests were performed according to ASTM D4172. All tests were performed at 75°C, 40 kg load, and 1200 rpm for 60 minutes.

[0249] The candidates were each added at 1 wt% to a Group II blend base oil of 45 wt% base oil at 6.5 cSt at 100°C and 55% base oil at 12 cSt at 100°C to meet an overall kinematic viscosity of 9 cSt at 100°C.

[0250] - Pin and V-block wear test: Falex pins and V-blocks are used to run this test.

[0251] The test was run at 100 lb for 3 minutes and then at 300 lb for 2 hours.

[0252] The candidates were each added at 1 wt% to a Group II blend base oil of 45 wt% base oil at 6.5 cSt at 100°C and 55% base oil at 12 cSt at 100°C to meet an overall kinematic viscosity of 9 cSt at 100°C.

[0253] result:

[0254]

[0255] Table 4

[0256] The results show that Invention 1 provides good wear resistance in both the 4-ball wear test and the pin and V-shaped wear test. The wear scar produced in the 4-ball wear test is smaller than that of Comparatives 1 and 3 and is equivalent to ZDDP (standard wear resistance). Similar performance was observed in the pin and V-shaped wear tests in terms of pin weight loss and diameter loss.

Claims

1. Use of a composition comprising at least one polymer P obtained by free-radical copolymerization of a mixture comprising: - at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom; - at least one monomer M1 which is an acrylic acid C1-C 10 Alkyl ester or methacrylate C1-C 10 alkyl esters; and - at least one monomer M2 which is acrylic acid C 11 -C 30 Alkyl ester or methacrylate C 11 -C 30 Alkyl esters.

2. Use according to claim 1, simultaneously as an anti-wear agent and friction coefficient reducer in oil-based lubricating compositions for engines and transmissions without clutches.

3. The use according to claim 1 or 2, wherein The monomer M1 is selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, n-heptyl (meth)acrylate, isoheptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, preferably 2-ethylhexyl (meth)acrylate.

4. The use according to any one of claims 1 to 3, wherein The monomer M2 is selected from the group consisting of n-undecyl(meth)acrylate, iso-undecyl(meth)acrylate, iso-dodecyl(meth)acrylate, n-tridecyl(meth)acrylate, n-tetradecyl(meth)acrylate, n-pentadecyl(meth)acrylate, n-hexadecyl(meth)acrylate, n-heptadecyl(meth)acrylate, n-octadecyl(meth)acrylate, n-nonadecyl(meth)acrylate, dodecyl(meth)acrylate, n-eicosyl(meth)acrylate and n-tricosyl(meth)acrylate, preferably dodecyl(meth)acrylate and dodecylmethacrylate.

5. The use according to any one of claims 1 to 4, wherein The polymer P comprises at least one monomer M2' which is a C11-C30 alkyl acrylate and at least one monomer M2" which is a C11-C30 alkyl methacrylate, more preferably dodecyl acrylate and dodecyl methacrylate.

6. The use according to claim 5, wherein The polymer P is obtained by free-radical copolymerization of a mixture consisting essentially of: - vinylphosphonic acid; -2-ethylhexyl acrylate; - dodecyl acrylate and - dodecyl methacrylate.

7. The use according to claim 6, wherein The polymer P is obtained by free-radical copolymerization of a mixture having the following molar ratios, based on the total amount of vinylphosphonic acid, 2-ethylhexyl acrylate, dodecyl acrylate and dodecyl methacrylate: - vinylphosphonic acid: 1% to 20%, notably 2% to 15%, preferably 5% to 10%; - 2-ethylhexyl acrylate: 10% to 90%, notably 20% to 80%, preferably 30% to 60%; - lauryl acrylate: 10% to 70%, notably 15% to 50% and more preferably 20% to 40%; - Lauryl methacrylate: 10% to 70%, notably 15% to 50% and more preferably 20% to 40%.

8. A synergistic composition comprising: at least one polymer P obtained by free-radical copolymerization of a mixture comprising: - at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom; - at least one monomer M1 which is an acrylic acid C1-C 10 Alkyl ester or methacrylate C1-C 10 alkyl esters; and - at least one monomer M2 which is acrylic acid C 11 -C 30 Alkyl ester or methacrylate C 11 -C 30 alkyl esters; and At least one friction modifier FM selected from the group consisting of organic molybdenum friction modifiers such as molybdenum dialkyldithiocarbamates and molybdenum dialkyldithiophosphates, and organic friction modifiers such as glycerides, fatty amides and fatty amines, preferably molybdenum dithiocarbamates and glycerol monooleate.

9. The synergistic composition according to claim 8, wherein The polymer P comprises at least one monomer M2' which is a C11-C30 alkyl acrylate and at least one monomer M2" which is a C11-C30 alkyl methacrylate, more preferably dodecyl acrylate and dodecyl methacrylate.

10. The synergistic composition according to claim 8 or 9, wherein The polymer P is obtained by free-radical copolymerization of a mixture consisting essentially of: - vinylphosphonic acid; -2-ethylhexyl acrylate; - dodecyl acrylate and - dodecyl methacrylate.

11. The synergistic composition according to claim 10, wherein The polymer P is obtained by free-radical copolymerization of a mixture having the following molar ratios, based on the total amount of vinylphosphonic acid, 2-ethylhexyl acrylate, dodecyl acrylate and dodecyl methacrylate: - vinylphosphonic acid: 1% to 20%, notably 2% to 15%, preferably 5% to 10%; - 2-ethylhexyl acrylate: 10% to 90%, notably 20% to 80%, preferably 30% to 60%; - lauryl acrylate: 10% to 70%, notably 15% to 50% and more preferably 20% to 40%; - Lauryl methacrylate: 10% to 70%, notably 15% to 50% and more preferably 20% to 40%.

12. The synergistic composition according to any one of claims 8 to 11, wherein The composition comprises from 0.1% to 10% by weight, preferably from 0.5% to 2.5% by weight, of at least one friction modifier FM, preferably glyceryl monooleate, based on the total weight of the composition.

13. A synergistic oil-based lubricant composition for clutchless engines and transmissions comprising: - at least one base oil, preferably a mineral oil or a synthetic base oil of Group II or III, notably a Group IV synthetic base oil, or a mixture thereof, and - A synergistic composition according to any one of claims 8 to 12.

14. A polymer obtained by free radical copolymerization of a mixture comprising: - at least one ethylenically unsaturated monomer P1 containing at least one phosphorus atom; - at least one monomer M1 which is a C1-C10 alkyl acrylate or a C1-C10 alkyl methacrylate; and at least one monomer M2′ which is a C11-C30 alkyl acrylate, and at least one monomer M2″ which is a C11-C30 alkyl methacrylate.

15. The polymer according to claim 14, obtained by free radical copolymerization of a mixture consisting essentially of: - vinylphosphonic acid; -2-ethylhexyl acrylate; - dodecyl acrylate and - dodecyl methacrylate.

16. Use of a composition comprising at least one polymer according to claim 14 or 15 for: - as polymeric anti-wear agents and friction modifiers in lubricants (including but not limited to engines, transmissions, hydraulic systems); and / or metalworking fluids (including but not limited to forming fluids and removal fluids) and / or greases (including but not limited to bearings, gears, wire ropes); or - As adhesion promoters and / or additives for providing corrosion resistance, i.e. in adhesive bonding of two surfaces, for bonding paints or varnishes or inks to metal surfaces, or as additives in coating compositions.

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