Anti-wear agents and lubricating oil compositions

Abstract

To provide an anti-wear agent with low copper corrosiveness and high wear prevention effect, and a lubricant composition containing the same.SOLUTION: An anti-wear agent comprises a copolymer (A) that comprises as essential constituent monomers a monomer (a) represented by general formula (1), a monomer (b) represented by general formula (2), and a monomer (c) represented by general formula (3), wherein the weight ratio (a / b) of the monomer (a) to the monomer (b) in the monomers constituting the copolymer (A) is 0.5 to 80.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to anti-wear agents and lubricating oil compositions. [Background technology]

[0002] In recent years, in order to improve fuel efficiency, there has been a demand for improved power transmission efficiency and smaller size and lighter weight in automotive transmissions. As a result, transmission mechanisms have evolved from manual transmissions to automatic transmissions, and more recently, continuously variable transmissions (CVTs) are being installed in some vehicles. Meanwhile, electric vehicles equipped with lead-acid batteries, nickel-metal hydride batteries, lithium-ion batteries, fuel cells, etc., and fitted with electric motors, or hybrid vehicles that use these batteries in combination with internal combustion engines, have been developed, and in these vehicles, transmission oil and electric motor oil have been used separately.

[0003] Recently, in electric vehicles and hybrid vehicles, there has been a growing demand for the standardization of these oils and for miniaturization and weight reduction by packaging the transmission and electric motor. As a result, there is a need for a new oil that possesses not only the wear-preventive properties of manual transmission oil, automatic transmission oil, or continuously variable transmission oil, but also the insulating properties and copper compatibility of electric motor oil.

[0004] Anti-wear agents are used to meet requirements such as wear prevention and seizure prevention, and generally, phosphate esters, zinc dithiophosphate, and organic sulfur compounds are added to mineral oil-based or synthetic base oils. However, transmission oils containing these anti-wear agents have a corrosive effect on copper and also have insufficient insulation properties, so when used as electric motor oil, problems such as damage to copper wires and short circuits in electric motors can occur. Therefore, in electric vehicles or hybrid vehicles, there is a need for anti-wear agents that can achieve both copper compatibility, insulation, and wear prevention.

[0005] Anti-wear agents that do not impair copper compatibility and insulation include polymer-type anti-wear agents that do not contain sulfur or phosphorus as constituent elements. Specifically, known examples include copolymers composed of α-olefin and fumarate ester (Patent Document 1), acrylic acid ester copolymers having hydroxyl groups (Patent Document 2), polyesters having hydrophilic polymer units and polyolefin units (Patent Document 3), and methacrylic acid ester copolymers having a block structure composed of polar segment units and hydrophobic segment units (Patent Document 4). However, the above polymer anti-wear agents have the problem that their anti-wear effect is not sufficient.

[0006] Furthermore, (meth)acrylic acid ester copolymers having monomers of a specific structure as essential constituent monomers are known as friction modifiers (Patent Documents 5, 6, and 7). However, while these friction modifiers have a high friction reduction effect, their wear prevention effect remains unclear. Moreover, the (meth)acrylic acid ester copolymer having a constituent monomer with a carboxyl group, as described in Patent Document 7, raises concerns about copper corrosion involving the carboxyl group, but this aspect has not been studied to date. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 3730660 [Patent Document 2] Patent No. 5822706 [Patent Document 3] Patent No. 5684832 [Patent Document 4] Japanese Patent Publication No. 4686444 [Patent Document 5] Japanese Patent Publication No. 2022-151618 [Patent Document 6] Patent No. 6582021 [Patent Document 7] Japanese Patent Publication No. 2020-139146 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The object of the present invention is to provide an anti-wear agent with low copper corrosiveness and high anti-wear effect, and a lubricating oil composition containing the same. [Means for solving the problem]

[0009] The inventors arrived at the present invention after diligent research. In other words, the present invention relates to an anti-wear agent containing a copolymer (A) having monomer (a) represented by the following general formula (1), monomer (b) represented by the following general formula (2), and monomer (c) represented by the following general formula (3) as essential constituent monomers, wherein the weight ratio (a / b) of monomer (a) to monomer (b) in the monomers constituting the copolymer (A) is 0.5 to 80; and a lubricating oil composition containing the anti-wear agent and a base oil.

[0010] [ka] [In general formula (1), A is a polymerizable unsaturated group having 2 to 5 carbon atoms; -X 1 -, -X 2 - and -X 3 - represents a group that is independently represented as -O- or -NH-; R 1 R is an alkylene group having 1 to 4 carbon atoms; 2 R is an alkylene group having 2 to 20 carbon atoms; 3 R is a hydrogen atom, a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms, a phenyl group in which the hydrogen atom in the aromatic ring may be substituted with a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms, an acyl group having a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms, or a benzoyl group in which the hydrogen atom in the aromatic ring may be substituted with a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms; p is an integer from 1 to 100, and if p is 2 or more, there are multiple R 2 and X 3 These may be the same or different.

[0011] [Chemical formula] [In general formula (2), R 4 represents a hydrogen atom or a methyl group; -X 4 - represents a group represented by -O- or -NH-; R 5 represents an alkylene group having 1 to 10 carbon atoms. q is an integer of 1 to 100, and when q is 2 or more, R 5 may be the same or different.]

[0012] [Chemical formula] [In general formula (3), R 6 represents a hydrogen atom or a methyl group; -X 5 - represents a group represented by -O- or -NH-; R 7 is a linear or branched alkyl group having 5 to 44 carbon atoms.] [Advantages of the Invention]

[0013] The antiwear agent of the present invention and the lubricating oil composition containing the antiwear agent of the present invention have the effects of low copper corrosiveness and excellent antiwear effect. [Modes for Carrying Out the Invention]

[0014] [Antiwear agent] [[ID=!45]]The antiwear agent of the present invention contains a copolymer (A) having a monomer (a) represented by the following general formula (1), a monomer (b) represented by the following general formula (2), and a monomer (c) represented by the following general formula (3) as essential constituent monomers. In the present invention, the weight ratio (a / b) of the monomer (a) to the weight of the monomer (b) in the monomers constituting the copolymer (A) is 0.5 to 80.

[0015] [Chemical formula] [In general formula (1), A is a polymerizable unsaturated group having 2 to 5 carbon atoms; -X 1 -, -X 2 - and -X 3 It should be noted that there seems to be an error in the original text where "!45" is present in the translation of item ID 45. It should likely be just "45" in the original text for a proper translation.- represents a group that is independently represented as -O- or -NH-; R 1 R is an alkylene group having 1 to 4 carbon atoms; 2 R is an alkylene group having 2 to 20 carbon atoms; 3 R is a hydrogen atom, a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms, a phenyl group in which the hydrogen atom in the aromatic ring may be substituted with a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms, an acyl group having a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms, or a benzoyl group in which the hydrogen atom in the aromatic ring may be substituted with a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms; p is an integer from 1 to 100, and if p is 2 or more, there are multiple R 2 and X 3 These may be the same or different.

[0016] [ka] [In general formula (2), R 4 is a hydrogen atom or a methyl group; -X 4 - represents the group -O- and -NH-; R 5 represents an alkylene group with 1 to 10 carbon atoms. q is an integer from 1 to 100, and R when q is 2 or greater. 5 They may be the same or different.

[0017] [ka] [In general formula (3), R 6 is a hydrogen atom or a methyl group; -X 5 - represents a group represented by -O- or -NH-; R 7 [It is a linear or branched alkyl group having 5 to 44 carbon atoms.]

[0018] <Copolymer (A)> In the present invention, copolymer (A) contains monomer (a) represented by general formula (1), monomer (b) represented by general formula (2), and monomer (c) represented by general formula (3) as essential constituent monomers, and the weight ratio (a / b) of monomer (a) to the weight of monomer (b) in the monomers constituting (A) is 0.5 to 80.

[0019] In the present invention, copolymer (A) contains monomer (a) represented by the general formula (1) as an essential constituent monomer. By containing monomer (a) as a constituent monomer, copolymer (A) can be made to have excellent wear prevention effect.

[0020] In general formula (1), A is a polymerizable unsaturated group having 2 to 5 carbon atoms. A polymerizable unsaturated group is a functional group having a carbon-carbon double bond that can undergo addition polymerization, and specifically refers to radical polymerizable unsaturated groups or cationic polymerizable unsaturated groups. Examples of polymerizable unsaturated groups include alkenyl groups having 2 to 5 carbon atoms {e.g., vinyl group, allyl group, homoallyl group (3-butenyl group), 2-butenyl group, methallyl group (2-methyl-1-propenyl group), 3-methyl-3-butenyl group, 3-methyl-2-butenyl group, 2-methyl-3-butenyl group, 2-methyl-2-butenyl group, and 1,1-dimethyl-2-propenyl group}, (meth)acryloyl group, etc. From the viewpoint of wear resistance, A is preferably a vinyl group and a (meth)acryloyl group, and more preferably a (meth)acryloyl group. In this invention, "(meth)acryloyl" means "acryloyl and / or methacryloyl," and "(meth)acrylate" means "acrylate and / or methacrylate."

[0021] -X in general formula (1) 1 -, -X 2 - and -X 3 Each of the hyphens represents a group that can be independently represented as -O- or -NH-. -X 1 -, -X 2 - and -X 3-From the viewpoint of wear prevention, -O- is preferred.

[0022] In general formula (1), R 1 This is an alkylene group having 1 to 4 carbon atoms. Examples of alkylene groups having 1 to 4 carbon atoms include methylene groups, ethylene groups, 1,2- or 1,3-propylene groups, and 1,2-, 1,3- or 1,4-butylene groups. Of these, from the viewpoint of wear prevention, ethylene groups and 1,2- or 1,3-propylene groups are preferred, and ethylene groups are more preferred.

[0023] In general formula (1), p represents the total number of moles of lactam and lactone added, as described below, and is an integer from 1 to 100. From the viewpoint of wear prevention and base oil solubility, it is preferably an integer from 1 to 70, more preferably an integer from 1 to 40, particularly preferably an integer from 1 to 20, and most preferably an integer from 1 to 10. If p is 2 or greater, there are multiple R 2 and X 3 These may be the same or different. In monomer (a) within the monomers constituting copolymer (A), the average value of p per mole of monomer (a) (average number of moles added, hereinafter also referred to as the molar average value of p) is preferably 1.9 to 70, more preferably 1.9 to 40, particularly preferably 1.9 to 20, and most preferably 1.9 to 10, from the viewpoint of wear prevention and base oil solubility. If the copolymer (A) consists of two or more monomers (a), the weighted average of the p values ​​of each monomer (a) based on the mole fraction of each monomer in monomer (a) is the molar mean value of p in general formula (1). When measuring p of monomer (a), 1The molar mean of p can be measured from the spectrum obtained by 1H-NMR (nuclear magnetic resonance) spectroscopy. For example, if the "lactam and / or lactone" is ε-caprolactone, the molar mean of p can be calculated by dividing half of the integral value of the peak around 1.4 ppm (the peak of the γ hydrogen of the carbonyl carbon derived from ε-caprolactone) by the integral value of the peak around 6.4 ppm or 6.1 ppm (one of the hydrogen atoms bonded to the unsaturated double bond of the acryloyl group or methacryloyl group). The γ hydrogen of the carbonyl carbon derived from ε-caprolactone is the structural formula derived from ε-caprolactone (-CO-CH2-CH2-C * This refers to the hydrogen atom bonded to the carbon atom marked with an asterisk (*) in the H2-CH2-CH2-O- (H2-CH2-CH2-O-) sequence. The hydrogen atom bonded to the unsaturated double bond of the acryloyl group is H2C, which is the structural formula of the acryloyl group. * =CH-CO- refers to the hydrogen atom bonded to the carbon atom marked with an asterisk. The hydrogen atom bonded to the unsaturated double bond of the methacryloyl group is H2C, which is the structural formula of the methacryloyl group. * =This refers to the hydrogen atom bonded to the carbon atom marked with an asterisk in C(CH3)-CO-. Specifically, the molar mean of p can be calculated using the following formula. (A in general formula (1) 1 (If it is an acryloyl group) The molar mean of p = (integral value of the peak of the γ hydrogen of the carbonyl carbon derived from ε-caprolactone / 2) / (integral value of one of the peaks of hydrogen atoms bonded to the unsaturated double bond of the acryloyl group) (A in general formula (1) 1 (If it is a methacryloyl group) The molar mean of p = (integral value of the peak of the γ hydrogen of the carbonyl carbon derived from ε-caprolactone / 2) / (integral value of one of the peaks of hydrogen atoms bonded to the unsaturated double bond of the methacryloyl group)

[0024] R in general formula (1) 2This represents an alkylene group having 2 to 20 carbon atoms. Specifically, alkylene groups having 2 to 20 carbon atoms include ethylene, isopropylene, 1,2- or 1,3-propylene, isobutylene, 1,2-, 1,3- or 1,4-butylene, isopentylene, 1,2-, 1,3-, 1,4- or 1,5-pentylene, isohexylene, 1,2-, 1,3-, 1,4-, 1,5- or 1,6-hexylene, isoheptylene, 1,2-, 1,3-, 1,4-, 1,5-, 1,6- or 1,7-heptylene, isooctylene, 1,8-octylene, isononylene, 1,9-nonylene, iso Examples include decylene group, 1,10-decylene group, isoundecylene group, 1,11-undecylene group, isododecylene group, 1,12-dodecylene group, isotridecylene group, 1,13-tridecylene group, isotetradecylene group, 1,14-tetradecylene group, isopentadecylene group, 1,15-pentadeciylene group, isohexadecylene group, 1,16-hexadecylene group, isoheptadeciylene group, 1,17-heptadeciylene group, isooctadecylene group, 1,18-isooctadecylene group, isononadecylene group, 1,19-isonononadecylene group, isoeicosilene group, 1,20-eicosilene group, and the like. R 2 From the viewpoint of wear prevention, the alkylene group is preferably a C2-C17 alkylene group, more preferably a C2-C15 alkylene group, particularly preferably a C2-C13 alkylene group, and most preferably a C2-C10 alkylene group.

[0025] R in general formula (1) 3 This is a hydrogen atom, a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms, a phenyl group in which the hydrogen atom in the aromatic ring may be substituted with a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms, an acyl group having a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms, or a benzoyl group in which the hydrogen atom in the aromatic ring may be substituted with a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms.

[0026] Specifically, linear or branched aliphatic hydrocarbon groups having 1 to 44 carbon atoms include saturated aliphatic strained hydrogen groups (alkyl groups) {for example, methyl group, ethyl group, propyl group, butyl group, hexyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, isononyl group, n-decyl group, isodecyl group, n-undecyl group, isoundecyl group, n-dodecyl group, isododecyl group, n-tridecyl group}. n-tetradecyl group, isotridecyl group, n-tetradecyl group, 2-ethyldodecyl group, n-pentadecyl group, 2-methyltetradecyl group, n-hexadecyl group, isohexadecyl group, n-heptadecyl group, isoheptadecyl group, 2-ethylpentadecyl group, 2-octylnonyl group, 2-(3-methylhexyl)-7-methylnonyl group, n-octadecyl group, isooctadecyl group, 2-hexylundecyl 2-ethylheptadecyl group, 1-hexyltridecyl group, n-icosyl group, 2-octylundecyl group, isoicosyl group, 1-undecyldodecyl group, 1-octylpentadecyl group, 2-decyltridecyl group, n-tetraicosyl group, 2-decyltetradecyl group, 2-dodecylpentadecyl group, 2-heptylicosyl group, 2-dodecylhexadecyl group, n-triacontyl group, 2-tetraicos Examples include residues obtained by removing hydroxyl groups from oxo alcohols derived from tetracontyl groups (such as tranecyloctadecyl groups, n-hexatriacontyl groups, n-tetracontyl groups, 2-ethyltetracontyl groups, etc.), unsaturated linear aliphatic hydrocarbon groups, and olefins [e.g., propylene oligomers (2-14 units), ethylene / propylene oligomers (2-20 units), and isobutene oligomers (2-10 units)].

[0027] Examples of phenyl groups in which the hydrogen atoms in the aromatic ring may be substituted with linear or branched aliphatic hydrocarbon groups having 1 to 44 carbon atoms include phenyl groups, o-, m-, or p-methylphenyl groups, and o-, m-, or p-ethylphenyl groups. Examples of acyl groups having a linear or branched aliphatic hydrocarbon group with 1 to 44 carbon atoms include acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, and piperoyl groups. Examples of benzoyl groups in which the hydrogen atoms in the aromatic ring may be substituted with linear or branched aliphatic hydrocarbon groups having 1 to 44 carbon atoms include benzoyl groups and toluyl groups.

[0028] These R 3 Of these, from the viewpoint of wear prevention, preferred are a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, a phenyl group which may be substituted with a linear alkyl

[0029] From the viewpoint of wear prevention, preferred monomers (a) include 1 to 100 mole lactone adducts of hydroxyalkyl (meth)acryloyl monomers (a1), 1 to 100 mole lactam adducts of hydroxyalkyl (meth)acryloyl monomers (a2), 1 to 100 mole lactone adducts of aminoalkyl (meth)acryloyl monomers (a3), and 1 to 100 mole lactam adducts of aminoalkyl (meth)acryloyl monomers (a4), as well as esterified products (a5) or amidated products (a6) of (a1) to (a4) with monocarboxylic acids (e.g., monocarboxylic acids having 2 to 45 carbon atoms), and etherified products (a7) resulting from the reaction of (a1) or (a3) ​​with alkylating agents or aromatic halides having 1 to 44 carbon atoms. More preferably, the monomer (a1) is a 1 to 100 mole lactone adduct of hydroxyalkyl (meth)acryloyl monomers.

[0030] Examples of hydroxyalkyl(meth)acryloyl monomers include hydroxyalkyl(meth)acrylates {hydroxymethyl(meth)acrylate, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, hydroxybutyl(meth)acrylate, etc.} and hydroxyalkyl(meth)acrylamides {hydroxymethyl(meth)acrylamide, hydroxyethyl(meth)acrylamide, hydroxypropyl(meth)acrylamide, hydroxybutyl(meth)acrylamide, etc.}.

[0031] Examples of aminoalkyl (meth)acryloyl monomers include aminoalkyl (meth)acrylates {aminomethyl (meth)acrylate, aminoethyl (meth)acrylate, aminopropyl (meth)acrylate, aminobutyl (meth)acrylate, etc.} and aminoalkyl (meth)acrylamides {aminomethyl (meth)acrylamide, aminoethyl (meth)acrylamide, aminopropyl (meth)acrylamide, aminobutyl (meth)acrylamide, etc.}.

[0032] Lactones include those with 3 to 21 carbon atoms, such as β-propiolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone.

[0033] Lactams include those with 3 to 21 carbon atoms, such as β-lactams, γ-lactams, and δ-lactams.

[0034] Examples of monocarboxylic acids include monocarboxylic acids having 2 to 45 carbon atoms {e.g., linear saturated aliphatic monocarboxylic acids (e.g., ethaneic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, etc.), linear unsaturated aliphatic monocarboxylic acids (e.g., oleic acid, linoleic acid, linolenic acid, arachidonic acid, docosahexanoic acid, etc.)}, aromatic monocarboxylic acids (e.g., benzoic acid, and those in which some of the hydrogen atoms bonded to the aromatic ring of benzoic acid are replaced by linear aliphatic hydrocarbon groups having 1 to 44 carbon atoms (e.g., 4-alkyl (alkyl group with 1 to 44 carbon atoms) benzoic acid, etc.)).

[0035] Examples of alkylating agents having 1 to 44 carbon atoms include alkyl chlorides such as methyl chloride, ethyl chloride, propyl chloride, butyl chloride, isopropyl chloride, and allyl chloride; and alkyl bromides such as methyl bromide, ethyl bromide, propyl bromide, butyl bromide, and isopropyl bromide. Aromatic halides include halogenated aromatic compounds such as fluorinated and chlorinated compounds, and examples include halogenated benzenes and halogenated alkylbenzenes having a chain-like aliphatic hydrocarbon group with 1 to 44 carbon atoms (e.g., 1-halogenated-4-alkyl(alkyl group with 1 to 44 carbon atoms)benzene).

[0036] From the viewpoint of wear resistance, the monomer (a) is preferably a 1-20 molar adduct of hydroxyalkyl (hydroxyalkyl group with 1-4 carbon atoms) (meth)acrylate lactone, an alkylated compound of a 1-12 carbon atom of a 1-20 molar adduct of hydroxyalkyl (hydroxyalkyl group with 1-4 carbon atoms) (meth)acrylate lactone, or an aromatic halogenated compound (which may have an alkyl group with 1-12 carbon atoms) of a 1-20 molar adduct of hydroxyalkyl (hydroxyalkyl group with 1-4 carbon atoms) (meth)acrylate lactone. Preferably, the esterified product is a hydroxyalkyl (hydroxyalkyl group with 1-4 carbon atoms) (meth)acrylate lactone adduct of 1-20 moles with a chain-like aliphatic monocarboxylic acid having 2-13 carbon atoms, or an esterified product is a hydroxyalkyl (hydroxyalkyl group with 1-4 carbon atoms) (meth)acrylate lactone adduct of 1-20 moles with an aromatic monocarboxylic acid (which may have an alkyl group with 1-12 carbon atoms), and more preferably, an ε-capturing product of hydroxyalkyl (hydroxyalkyl group with 2-3 carbon atoms) (meth)acrylate. 1-20 molar adducts of loractone, alkylated 1-12 carbon atoms of 1-20 molar adducts of hydroxyalkyl (hydroxyalkyl group with 2-3 carbon atoms) (meth)acrylate of ε-caprolactone, aromatic (may have an alkyl group with 1-12 carbon atoms) halogenated adducts of 1-20 molar adducts of hydroxyalkyl (hydroxyalkyl group with 2-3 carbon atoms) (meth)acrylate of ε-caprolactone, 1-20 molar adducts of hydroxyalkyl (hydroxyalkyl group with 2-3 carbon atoms) (meth)acrylate of ε-caprolactone The adduct is an esterified product of a chain-like aliphatic monocarboxylic acid having 2 to 13 carbon atoms, or an esterified product of a 1 to 20 molar adduct of hydroxyalkyl (hydroxyalkyl group having 2 to 3 carbon atoms) (meth)acrylate to ε-caprolactone with an aromatic (may have an alkyl group having 1 to 12 carbon atoms) monocarboxylic acid, and particularly preferably a 1 to 20 molar adduct of hydroxyethyl (meth)acrylate to ε-caprolactone, or an alkylated product of a 1 to 12 carbon atom adduct of hydroxyethyl (meth)acrylate to ε-caprolactone.These are aromatic halides (may have an alkyl group with 1 to 12 carbon atoms) of 1 to 20 molar adducts of hydroxyethyl (meth)acrylate to ε-caprolactone, esterified esters of 1 to 20 molar adducts of hydroxyethyl (meth)acrylate to ε-caprolactone with a chain-like aliphatic monocarboxylic acid with 2 to 13 carbon atoms, and esterified esters of 1 to 20 molar adducts of hydroxyethyl (meth)acrylate to ε-caprolactone with aromatic monocarboxylic acids (may have an alkyl group with 1 to 12 carbon atoms).

[0037] Lactone adducts of hydroxyalkyl (meth)acryloyl monomers or aminoalkyl (meth)acryloyl monomers in amounts of 1 to 100 moles can be obtained, for example, by ring-opening addition of a lactone to a hydroxyalkyl (meth)acryloyl monomer or aminoalkyl (meth)acryloyl monomer. The reaction temperature for the ring-opening addition reaction is preferably 80 to 150°C, and more preferably 100 to 140°C, from the viewpoint of reaction time. The reaction time is preferably 2 to 24 hours, and more preferably 3 to 10 hours. The reaction may be carried out in the presence of a catalyst. Any known catalyst can be used as the catalyst for the above reaction, including p-toluenesulfonic acid, tetrapropyl titanate, and stannous octanoate. The amount of catalyst used is preferably 0.01 to 5% by mass, and more preferably 0.03 to 0.5% by mass, relative to the amount of reaction product. After the ring-opening addition reaction is complete, it is desirable to treat the catalyst by methods such as adsorption and filtration using an adsorbent, or neutralization to deactivate the catalyst.

[0038] Lactam adducts of hydroxyalkyl (meth)acryloyl monomers or aminoalkyl (meth)acryloyl monomers in quantities of 1 to 100 moles can be obtained, for example, by ring-opening addition of a lactam to a hydroxyalkyl (meth)acryloyl monomer or aminoalkyl (meth)acryloyl monomer. The reaction temperature for the ring-opening addition reaction of lactam is preferably 80 to 150°C, and more preferably 100 to 140°C, from the viewpoint of reaction time. The reaction time is preferably 2 to 24 hours, and more preferably 3 to 10 hours. The reaction may be carried out in the presence of a catalyst. Any known catalyst can be used as the catalyst for the above reaction, such as tetrapropyl titanate or stannous octanoate. The amount of catalyst used is preferably 0.01 to 5% by weight, and more preferably 0.03 to 0.5% by weight, relative to the amount of reaction product. After the ring-opening addition reaction is complete, it is desirable to treat the catalyst by methods such as adsorption and filtration using an adsorbent, or neutralization to deactivate the catalyst.

[0039] The reaction temperature when esterifying (a1) to (a4) with a monocarboxylic acid is preferably 80°C to 150°C, and more preferably 90°C to 130°C, from the viewpoint of reaction time and prevention of polymerization of (meth)acrylic acid. The esterification reaction may be carried out under reduced pressure to remove the water produced. The preferred reaction pressure is preferably 0.007 to 0.095 MPa, and more preferably 0.01 to 0.092 MPa, from the viewpoint of reaction time and polymerization prevention. The reaction time is preferably 2 to 24 hours, and more preferably 3 to 10 hours. The esterification reaction is preferably carried out in the presence of a catalyst. Any known catalyst can be used as the catalyst for the esterification reaction described above, such as sulfuric acid or p-toluenesulfonic acid. A solvent may also be used in the esterification reaction, and suitable solvents include those that are non-aqueous and have a boiling point of 150°C or lower, such as cyclohexane and toluene.

[0040] The reaction temperature when amidating (a1) to (a4) with a monocarboxylic acid is preferably 80°C to 150°C, and more preferably 90°C to 130°C, from the viewpoint of reaction time and prevention of polymerization of (meth)acrylic acid. Furthermore, the amidation reaction may be carried out under reduced pressure to remove the water produced. The preferred reaction pressure is preferably 0.007 to 0.095 MPa, and more preferably 0.01 to 0.092 MPa, from the viewpoint of reaction time and polymerization prevention. The reaction time is preferably 2 to 24 hours, and more preferably 3 to 10 hours.

[0041] The reaction between (a1) or (a3) ​​and an alkylating agent having 1 to 44 carbon atoms can be obtained by reacting under general conditions in the presence of an alkali (e.g., an amine, a quaternary ammonium salt, sodium hydroxide, etc.).

[0042] From the viewpoint of solubility in lubricating oil base oil, the constituent units derived from monomer (a) (structures in which the polymerizable vinyl groups of (a) react to form single bonds) are preferably those that have a specific solubility parameter (sometimes abbreviated as SP value below). The SP value of the constituent unit derived from monomer (a) is preferably 9.0 to 12.5 (cal / cm³). 3 ) 1 / 2 And more preferably 9.3 to 12.3 (cal / cm²). 3 ) 1 / 2 And, particularly preferably, 9.5 to 12.0 (cal / cm²). 3 ) 1 / 2 That is the case. In this invention, the SP value refers to the value calculated using formula (28) on page 153 of the Fedors method (Polymer Engineering and Science, February, 1974, Vol. 14, No. 2, pp. 147-154), using the numerical values ​​(heat of vaporization and molar volume of atoms or functional groups at 25°C) listed on page 152 (Table 5). Specifically, it refers to the Δe parameter of the Fedors method, as listed in Table 1 below. i and v i The values ​​can be used to calculate the following formula by applying the values ​​corresponding to the types of atoms and atomic groups within the molecular structure. SP value = (ΣΔe i / Σv i ) 1 / 2

[0043] [Table 1]

[0044] Furthermore, when copolymer (A) uses two or more monomers (a) as monomers, it is preferable that the SP value of monomer (a) is calculated by determining the SP value of each of the multiple monomers constituting (A) using the method described above, and then taking the arithmetic mean of the SP values ​​of each monomer (a) based on their weight fractions, so that the value is within the range described above.

[0045] The molecular formula weight or number average molecular weight (hereinafter abbreviated as Mn) of monomer (a) is preferably 150 to 20,000, more preferably 150 to 10,000, particularly preferably 150 to 7,000, and most preferably 150 to 4,000, from the viewpoint of wear prevention. Furthermore, the molecular weight or Mn of (a), and the weight-average molecular weight (hereinafter abbreviated as Mw) of copolymer (A) described later can be measured by gel permeation chromatography (hereinafter abbreviated as GPC) under the following conditions. <Measurement conditions for Mn in (a) and Mw in (A)> Device: "HLC-8320GPC" [Manufactured by Tosoh Corporation] Columns: 1 x "TSKgel guardcolumn SuperHZ-L" [manufactured by Tosoh Corporation], 3 x "TSKgel Super HZM-M" [manufactured by Tosoh Corporation] Measurement temperature: 40℃ Sample solution: 0.25% by weight tetrahydrofuran solution Solution injection volume: 10μl Detection device: RI (Differential Refractometer) Reference material: Standard polystyrene (TSKstandard POLYSTYRENE) 11 samples (molecular weight: 589, 1,013, 2,630, 9,100, 19,500, 37,900, 96,400, 190,000, 427,000, 1,090,000, 2,110,000) [Manufactured by Tosoh Corporation]

[0046] In the present invention, copolymer (A) contains monomer (b) represented by the general formula (2) as an essential constituent monomer. In the present invention, it is presumed that by having monomer (b) as a constituent monomer of copolymer (A), the carboxyl groups of monomer (b) enhance the adsorption force to the metal, thereby improving the wear prevention effect.

[0047] R in general formula (2) 4 This is either a hydrogen atom or a methyl group, and of these, both a hydrogen atom and a methyl group are preferred from the viewpoint of preventing wear.

[0048] -X in general formula (2) 4 - represents a group represented by -O- or -NH-, and of these, the group represented by -O- is preferred from the viewpoint of preventing wear.

[0049] R in general formula (2) 5 This is an alkylene group having 1 to 10 carbon atoms. Examples of alkylene groups having 1 to 10 carbon atoms include methylene, ethylene, isopropylene, 1,2- or 1,3-propylene, isobutylene, 1,2-, 1,3- or 1,4-butylene, isopentylene, 1,2-, 1,3-, 1,4- or 1,5-pentylene, isohexylene, 1,2-, 1,3-, 1,4-, 1,5- or 1,6-hexylene, isoheptylene, 1,2-, 1,3-, 1,4-, 1,5-, 1,6- or 1,7-heptylene, isooctylene, 1,8-octylene, isononylene, 1,9-nonylene, isodecylene, and 1,10-decylene. Of these, alkylene groups having 1 to 8 carbon atoms are preferred from the viewpoint of preventing wear, alkylene groups having 2 to 6 carbon atoms are more preferred, and alkylene groups having 2 to 5 carbon atoms are particularly preferred.

[0050] In general formula (2), q is an integer from 1 to 100, preferably an integer from 1 to 50, more preferably an integer from 1 to 20, and particularly preferably an integer from 1 to 10 from the viewpoint of preventing wear. Multiple R when q is 2 or more 5 They may be the same or different.

[0051] Specific examples of monomer (b) include carboxyalkyl (1-10 carbon atoms) (meth)acrylate, carboxypolyacetactone mono(meth)acrylate (with 2-100 moles of α-acetactone added), carboxypolypropiolactone mono(meth)acrylate (with 2-100 moles of β-propiolactone added), carboxypolybutyrolactone mono(meth)acrylate (with 2-100 moles of γ-butyrolactone added), carboxypolyvalerolactone mono(meth)acrylate (with 2-100 moles of δ-valerolactone added), and carboxypolycaprolactone mono(meth)acrylate (with 2-100 moles of ε-caprolactone added).

[0052] Monomer (b) can be obtained, for example, by the reaction of a lactone having 2 to 11 carbon atoms (e.g., α-acetolactone, β-propiolactone, γ-butyrolactone, β-butyrolactone, δ-valerolactone, γ-valerolactone, ε-caprolactone, δ-caprolactone, and γ-caprolactone, etc.) with (meth)acrylic acid or (meth)acrylamide. Furthermore, monomers (b) such as β-carboxyethyl acrylate (product name "β-CEA", manufactured by Daicel Ornex Corporation) and ω-carboxy-polycaprolactone (2-mol adduct) monoacrylate (product name "Aronics M-5300", manufactured by Toagosei Co., Ltd.) are commercially available and can be obtained.

[0053] In the present invention, copolymer (A) contains monomer (c) represented by the general formula (3) as an essential constituent monomer. The inclusion of monomer (c) as a constituent monomer tends to make it easier to dissolve in the base oil.

[0054] R in general formula (3) 6 This is either a hydrogen atom or a methyl group, and of these, a methyl group is preferred from the viewpoint of wear prevention and viscosity index improvement effect.

[0055] -X in general formula (3) 5- is a group represented by -O- or NH-, and of these, -O- is preferred from the viewpoint of wear prevention.

[0056] R in general formula (3) 7 These are linear or branched alkyl groups having 5 to 44 carbon atoms, for example, pentyl group, hexyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, isononyl group, n-decyl group, isodecyl group, n-undecyl group, isoundecyl group, n-dodecyl group, isododecyl group, n-tridecyl group, isotridecyl group, n-tetradecyl group, 2-ethyldodecyl group, n-pentadecyl group, 2-methyltetradecyl group, n-hexadecyl group, isohexadecyl group, n-heptadecyl group, isoheptadecyl group, 2-ethylpentadecyl group, 2-octylnonyl group, 2-(3-methylhexyl)-7-methylnonyl group, n-octadecyl group, isooctadecyl group, 2-hexylundecyl group, Examples include 2-ethylheptadecyl group, 1-hexyltridecyl group, n-icosyl group, 2-octylundecyl group, isoicosyl group, 1-undecyldodecyl group, 1-octylpentadecyl group, 2-decyltridecyl group, n-tetraicosyl group, 2-decyltetradecyl group, 2-dodecylpentadecyl group, 2-heptylicosyl group, 2-dodecylhexadecyl group, n-triacontyl group, 2-tetradecyloctadecyl group, n-hexatriacontyl group, n-tetracontyl group, 2-ethyltetracontyl group, and olefins [e.g., propylene oligomers (2-14 units), ethylene / propylene oligomers (2-20 units), and isobutene oligomers (2-10 units), etc.].

[0057] R 7 Of these, from the viewpoint of base oil solubility, linear or branched alkyl groups having 10 to 34 carbon atoms are preferred, more preferably linear or branched alkyl groups having 12 to 32 carbon atoms are preferred, particularly preferably linear or branched alkyl groups having 16 to 32 carbon atoms are preferred, and most preferably linear alkyl groups having 16 to 22 carbon atoms and branched alkyl groups having 18 to 32 carbon atoms are preferred.

[0058] Examples of monomers (c) include pentyl (meth)acrylate, hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-undecyl (meth)acrylate, isoundecyl (meth)acrylate, n-dodecyl (meth)acrylate, isododecyl (meth)acrylate, n-tridecyl (meth)acrylate, Isotridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, 2-ethyldodecyl (meth)acrylate, n-pentadecyl (meth)acrylate, 2-methyltetradecyl (meth)acrylate, n-hexadecyl (meth)acrylate, isohexadecyl (meth)acrylate, n-heptadecyl (meth)acrylate, isoheptadecyl (meth)acrylate, 2-ethylpentadecyl (meth)acrylate, 2-octyrnonyl (meth)acrylate, 2-(3-methylhexyl)-7-methyl Lu-nonyl (meth)acrylate, n-octadecyl (meth)acrylate, isooctadecyl (meth)acrylate, 2-hexylundecyl (meth)acrylate, 2-ethylheptadecyl (meth)acrylate, 1-hexyltridecyl (meth)acrylate, n-icosyl (meth)acrylate, 2-octylundecyl (meth)acrylate, isoicosyl (meth)acrylate, 1-undecyldodecyl (meth)acrylate, 1-octylpentadecyl (meth)acrylate, 2-decyltridecyl (meth)acrylate Examples include acrylate, n-tetraicosyl (meth)acrylate, 2-decyltetradecyl (meth)acrylate, 2-dodecylpentadecyl (meth)acrylate, 2-heptylicosyl (meth)acrylate, 2-dodecylhexadecyl (meth)acrylate, n-triacontyl (meth)acrylate, 2-tetradecyloctadecyl (meth)acrylate, n-hexatriacontyl (meth)acrylate, n-tetracontyl (meth)acrylate, and 2-ethyltetracontyl (meth)acrylate. Of these, 2-decyltetradecyl(meth)acrylate, 2-dodecylhexadecyl(meth)acrylate, and 2-tetradecyloctadecyl(meth)acrylate are preferred from the viewpoint of wear prevention, and more preferably 2-dodecylhexadecyl(meth)acrylate and 2-tetradecyloctadecyl(meth)acrylate.

[0059] Copolymer (A) may contain monomers other than those mentioned above as constituent monomers. For example, it may be a copolymer in which one or more monomers are selected from the group consisting of nitrogen atom-containing monomers (d) other than monomers (a) to (c), hydroxyl group-containing monomers (e) other than monomer (a), and phosphorus atom-containing monomers (f). Furthermore, polymer (A) may contain the following monomers (g) to (n), and a carboxyl-containing monomer (t) other than monomer (b) as constituent monomers.

[0060] Examples of nitrogen atom-containing monomers (d) include the following monomers (d1) to (d4). Amide group-containing monomer (d1): (meth)acrylamide, monoalkylaminoalkyl(meth)acrylamide [having an aminoalkyl group (2-6 carbon atoms) with one C1-4 alkyl group bonded to the nitrogen atom; for example, N-methylaminoethyl(meth)acrylamide, N-ethylaminoethyl(meth)acrylamide, N-isopropylamino-n-butyl(meth)acrylamide and Nn- or isobutylamino-n-butyl(meth)acrylamide, etc.], dialkylamino(meth)acrylamide [having two C1-4 alkyl groups bonded to the nitrogen atom; for example, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide and N, Examples include those having a nitrogen atom only in the amide group, such as N-di-n-butyl(meth)acrylamide, dialkylaminoalkyl(meth)acrylamide [those having an aminoalkyl group (2-6 carbon atoms) in which two alkyl groups with 1-4 carbon atoms are bonded to the nitrogen atom; for example, N,N-dimethylaminoethyl(meth)acrylamide, N,N-diethylaminoethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, and N,N-di-n-butylaminobutyl(meth)acrylamide, etc.], and N-vinyl carboxylic acid amide [N-vinylformamide, N-vinylacetamide, N-vinyl-n- or isopropionylamide, and N-vinylhydroxyacetamide, etc.].

[0061] Nitro group-containing monomer (d2): Examples include 4-nitrostyrene.

[0062] Monomers containing primary to tertiary amino groups (d3): Primary amino group-containing vinyl monomers {alkenylamines with 3-6 carbon atoms [(meth)allylamine and clotylamine, etc.], aminoalkyl (2-6 carbon atoms) (meth)acrylates [aminoethyl (meth)acrylate, etc.]}; Secondary amino group-containing vinyl monomers {monoalkylaminoalkyl (meth)acrylates [those having an aminoalkyl group (2-6 carbon atoms) in which one alkyl group with 1-6 carbon atoms is bonded to a nitrogen atom; for example, t-butylaminoethyl (meth)acrylate and methylaminoethyl (meth)acrylate, etc.], dialkenylamines with 6-12 carbon atoms [di(meth)allylamine, etc.]}; Tertiary amino group-containing vinyl monomers {dialkylaminoalkyl (meth)acrylates [nitrogen atom Examples include aminoalkyl groups (with 2 to 6 carbon atoms) to which two alkyl groups with 1 to 6 carbon atoms are bonded; for example, dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate, etc., alicyclic (meth)acrylates having a nitrogen atom [morpholinoethyl (meth)acrylate, etc.], aromatic vinyl monomers [N,N-diphenylaminoethyl (meth)acrylamide, N,N-dimethylaminostyrene, 4-vinylpyridine, 2-vinylpyridine, N-vinylpyrrole, N-vinylpyrrolidone and N-vinylthiopyrrolidone, etc.], and their hydrochloride salts, sulfates, phosphates, or lower alkyl (1 to 8 carbon atoms) monocarboxylic acid (acetic acid and propionic acid, etc.) salts.

[0063] Nitrile group-containing monomer (d4): Examples include (meth)acrylonitrile.

[0064] Of the nitrogen atom-containing vinyl monomers (d), (d1) and (d3) are preferred, and more preferably are N,N-diphenylaminoethyl(meth)acrylamide, dimethylaminoethyl(meth)acrylamide, diethylaminoethyl(meth)acrylamide, dimethylaminopropyl(meth)acrylamide, dimethylaminoethyl(meth)acrylate, and diethylaminoethyl(meth)acrylate.

[0065] Examples of hydroxyl group-containing monomers (e) include the following: Hydroxyl group-containing aromatic monomers (e.g., p-hydroxystyrene), hydroxyalkyl (C2-C6) (meth)acrylates [e.g., 2-hydroxyethyl (meth)acrylate and 2- or 3-hydroxypropyl (meth)acrylate], mono- or di-hydroxyalkyl (C1-C4) substituted (meth)acrylamides [e.g., N,N-dihydroxymethyl (meth)acrylamide, N,N-dihydroxypropyl (meth)acrylamide, N,N-di-2-hydroxybutyl (meth)acrylamide], vinyl alcohol, C3-C12 alkenols [e.g., (meth)aryl alcohol, clotyl alcohol, isocyl alcohol] Examples include rotyl alcohol, 1-octenol and 1-undecenol, etc., alkene monools or alkene diols having 4 to 12 carbon atoms [1-buten-3-ol, 2-buten-1-ol and 2-buten-1,4-diol, etc.], hydroxyalkyl (1 to 6 carbon atoms) alkenyl (3 to 10 carbon atoms) ethers (2-hydroxyethylpropenyl ether, etc.), alkenyl (3 to 10 carbon atoms) ethers or (meth)acrylates of polyhydric (3 to 8 hydric) alcohols (glycerin, pentaerythritol, sorbitol, sorbitan, diglycerin, sugars and sucrose, etc.) [sucrose (meth)allyl ether, etc.].

[0066] Examples of phosphorus atom-containing monomers (f) include the following monomers (f1) to (f2).

[0067] Phosphate ester group-containing monomer (f1): Examples include (meth)acryloyloxyalkyl (C2-C4) phosphate esters [(meth)acryloyloxyethyl phosphate and (meth)acryloyloxyisopropyl phosphate] and alkenyl phosphate esters [vinyl phosphate, allyl phosphate, propenyl phosphate, isopropenyl phosphate, butenyl phosphate, pentenyl phosphate, octenyl phosphate, decenyl phosphate and dodecenyl phosphate, etc.].

[0068] Phosphono group-containing monomer (f2): Examples include (meth)acryloyloxyalkyl (C2-C4) phosphonic acids [(meth)acryloyloxyethylphosphonic acid, etc.] and alkenyl (C2-C12) phosphonic acids [vinylphosphonic acid, allylphosphonic acid, octenylphosphonic acid, etc.].

[0069] Of the phosphorus atom-containing monomers (f), (f1) is preferred, (meth)acryloyloxyalkyl (2-4 carbon atoms) phosphate esters are preferred, and (meth)acryloyloxyethyl phosphate is particularly preferred.

[0070] Alkoxyalkyl ether monomer (g); Methoxyethyl (meth)acrylate, methoxypropyl (meth)acrylate, methoxybutyl (meth)acrylate, methoxyheptyl (meth)acrylate, methoxyhexyl (meth)acrylate, methoxypentyl (meth)acrylate, methoxyoctyl (meth)acrylate, ethoxyethyl (meth)acrylate, ethoxypropyl (meth)acrylate, ethoxybutyl (meth)acrylate, ethoxyheptyl (meth)acrylate, ethoxyhexyl (meth)acrylate, ethoxypentyl (meth)acrylate, ethoxyoctyl (meth)acrylate, propoxymethyl (meth)acrylate, propoxyethyl Examples include propoxypropyl (meth)acrylate, propoxybutyl (meth)acrylate, propoxyheptyl (meth)acrylate, propoxyhexyl (meth)acrylate, propoxypentyl (meth)acrylate, propoxyoctyl (meth)acrylate, butoxymethyl (meth)acrylate, butoxyethyl (meth)acrylate, butoxypropyl (meth)acrylate, butoxybutyl (meth)acrylate, butoxyheptyl (meth)acrylate, butoxyhexyl (meth)acrylate, butoxypentyl (meth)acrylate, butoxyoctyl (meth)acrylate, etc. Of the monomers (g), preferred are methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, and butoxyethyl (meth)acrylate.

[0071] Aliphatic hydrocarbon monomers (h): Examples include alkenes with 2 to 20 carbon atoms (ethylene, propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, and octadecene, etc.) and alkadienes with 4 to 12 carbon atoms (butadiene, isoprene, 1,4-pentadiene, 1,6-heptadiene, and 1,7-octadiene, etc.).

[0072] Alicyclic hydrocarbon monomers (i): Examples include cyclohexene, (di)cyclopentadiene, pinene, limonene, vinylcyclohexene, and ethylidene bicycloheptene.

[0073] Aromatic hydrocarbon monomers (j): Examples include styrene, α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, 4-ethylstyrene, 4-isopropylstyrene, 4-butylstyrene, 4-phenylstyrene, 4-cyclohexylstyrene, 4-benzylstyrene, indene, 4-clotylbenzene, and 2-vinylnaphthalene.

[0074] Vinyl esters, vinyl ethers, vinyl ketones (k): Examples include vinyl esters of saturated fatty acids having 2 to 12 carbon atoms (vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl octanoate, etc.), alkyl, aryl, or alkoxyalkyl vinyl ethers having 1 to 12 carbon atoms (methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, phenyl vinyl ether, vinyl-2-methoxyethyl ether, and vinyl-2-butoxyethyl ether, etc.), and alkyl or aryl vinyl ketones having 1 to 8 carbon atoms (methyl vinyl ketone, ethyl vinyl ketone, and phenyl vinyl ketone, etc.).

[0075] Epoxy group-containing monomer (l): Examples include glycidyl (meth)acrylate and glycidyl (meth)allyl ether.

[0076] Halogen element-containing monomer (m): Examples include vinyl chloride, vinyl bromide, vinylidene chloride, (meth)allyl chloride, and halogenated styrenes (such as dichlorostyrene).

[0077] Esters (n) of unsaturated polycarboxylic acids: Examples include alkyl, cycloalkyl, or aralkyl esters of unsaturated polycarboxylic acids [alkyl diesters of unsaturated dicarboxylic acids (maleic acid, fumaric acid, and itaconic acid, etc.) having 1 to 8 carbon atoms (dimethyl maleate, dimethyl fumarate, diethyl maleate, and dioctyl maleate)].

[0078] Examples of carboxyl group-containing monomers (t) include (meth)acrylic acid, monomer (t1) represented by the following general formula (4), monomer (t2) represented by the following general formula (5), and monomer (t3) represented by the following general formula (6).

[0079] [ka] [R in general formula (4)] 8 is a hydrogen atom or a methyl group; -X 6 - represents a group represented by -O- or -NH-; R 9 R is an alkylene group having 1 to 10 carbon atoms; 10 O is an alkylene oxy group with 2 to 4 carbon atoms; R 11 represents an alkylene group with 1 to 12 carbon atoms. u is an integer from 0 to 10, and R when u is 2 or greater. 10 O can be the same or different.

[0080] [ka]

[0081] [R in general formula (5)] 12 is a hydrogen atom or a methyl group; -X 7 - represents a group represented by -O- or -NH-; R 13R is an alkylene group having 1 to 10 carbon atoms; 14 O is an alkylene oxy group with 2 to 4 carbon atoms; R 15 Each of these is independently either a hydrogen atom or a carboxyl group, and at least one represents a carboxyl group. v is an integer from 0 to 10, and when v is 2 or greater, R 14 O can be the same or different.

[0082] [ka]

[0083] [R in general formula (6)] 16 is a hydrogen atom or a methyl group; -X 8 - represents a group represented by -O- or -NH-; R 17 R is an alkylene group having 1 to 10 carbon atoms; 18 O is an alkylene oxy group with 2 to 4 carbon atoms; R 19 Each of these is independently either a hydrogen atom or a carboxyl group, and at least one represents a carboxyl group. r is an integer from 0 to 10, and when r is 2 or greater, R 18 O can be the same or different.

[0084] Monomer (t1) is a monomer having one carboxyl group, represented by the general formula (4) above. R in general formula (4) 8 This is either a hydrogen atom or a methyl group, and of these, both hydrogen atoms and methyl groups are preferred from the viewpoint of wear prevention.

[0085] -X in general formula (4) 6 - represents a group represented by -O- or NH-, of which -O- is preferred from the viewpoint of wear prevention.

[0086] R in general formula (4) 9 This is an alkylene group having 1 to 10 carbon atoms. Examples of the alkylene group having 1 to 10 carbon atoms include a methylene group, an ethylene group, an isopropylene group, a 1,2- or 1,3-propylene group, an isobutylene group, a 1,2-, 1,3- or 1,4-butylene group, an isopentylene group, a 1,2-, 1,3-, 1,4- or 1,5-pentylene group, an isohexylene group, a 1,2-, 1,3-, 1,4-, 1,5- or 1,6-hexylene group, an isoheptylene group, a 1,2-, 1,3-, 1,4-, 1,5-, 1,6- or 1,7-heptylene group, an isooctylene, a 1,8-octylene group, an isononylene group, a 1,9-nonylene group, an isodecylene group, a 1,10-decylene group, and the like. Among these, from the viewpoint of anti-wear property, an ethylene group, a 1,2-propylene group, and a 1,3-propylene group are preferable, and an ethylene group is more preferable.

[0087] R in the general formula (4) 10 O is an alkyleneoxy group having 2 to 4 carbon atoms. Examples of the alkyleneoxy group having 2 to 4 carbon atoms include an ethyleneoxy group, a propyleneoxy group, a butyleneoxy group, and the like. Examples of the propylene group in the propyleneoxy group include a 1,2-propylene group and a 1,3-propylene group, and examples of the butylene group in the butyleneoxy group include a 1,2-butylene group, a 1,3-butylene group, and a 1,4-butylene group. From the viewpoint of anti-wear property, the alkyleneoxy group is preferably an ethyleneoxy group and a propyleneoxy group, and more preferably an ethyleneoxy group.

[0088] u in the general formula (4) is an integer of 0 to 10, preferably an integer of 0 to 7, more preferably an integer of 0 to 5, and particularly preferably an integer of 0 to 3 from the viewpoint of anti-wear property. When u is 2 or more, a plurality of R 10 O may be the same or different.

[0089] R in the general formula (4) 11 is a residue obtained by removing two carboxyl groups from a dicarboxylic acid having 3 to 14 carbon atoms and is an alkylene group having 1 to 12 carbon atoms. Examples of alkylene groups having 1 to 12 carbon atoms include methylene, ethylene, isopropylene, 1,2- or 1,3-propylene, isobutylene, 1,2-, 1,3- or 1,4-butylene, isopentylene, 1,2-, 1,3-, 1,4- or 1,5-pentylene, isohexylene, 1,2-, 1,3-, 1,4-, 1,5- or 1,6-hexylene, isoheptylene, 1,2-, 1,3-, 1,4-, 1,5-, 1,6- or 1,7-heptylene, isooctylene, 1,8-octylene, isononylene, 1,9-nonylene, isodecylene, 1,10-decylene, 1,11-undecylene, and 1,12-dodecylene. Of these, alkylene groups having 1 to 6 carbon atoms are preferred from the viewpoint of wear prevention, and alkylene groups having 1 to 4 carbon atoms are more preferred. Examples of dicarboxylic acids having 3 to 14 carbon atoms include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanediic acid, and alkyl succinic acid (such as succinic acid having an alkyl group with 1 to 10 carbon atoms).

[0090] Specific examples of monomers (t1) include monoesters of hydroxyalkyl (C1-C10) (meth)acrylates and C3-C14 dicarboxylic acids {for example, mono(2-(meth)acryloyloxyethyl) malonate, mono(3-(meth)acryloyloxy-n-propyl) malonate, mono(meth)acryloyloxyisopropyl malonate, mono(4-(meth)acryloyloxy-n-butyl) malonate, mono(meth)acryloyloxyisobutyl malonate, mono(6-(meth)acryloyloxy-n-hexyl) malonate, mono(meth)acryloyloxy-n-hexyl) malonate (8-(meth)acryloyloxy-n-octyl), mono(10-(meth)acryloyloxy-n-decyl) malonate, mono(meth)acryloyloxyisodecyl malonate, mono(2-(meth)acryloyloxyethyl) succinate, mono(3-(meth)acryloyloxy-n-propyl) succinate, mono(meth)acryloyloxyisopropyl succinate, mono(4-(meth)acryloyloxy-n-butyl) succinate, mono(meth)acryloyloxyisobutyl succinate, mono(6-(meth)acryloyloxy-n-hexyl) succinate ), mono(8-(meth)acryloyloxy-n-octyl) succinate, mono(10-(meth)acryloyloxy-n-decyl) succinate, mono(meth)acryloyloxyisodecyl succinate, mono(2-(meth)acryloyloxyethyl) glutanate, mono(3-(meth)acryloyloxy-n-propyl) glutanate, mono(meth)acryloyloxyisopropyl glutanate, mono(4-(meth)acryloyloxy-n-butyl) glutanate, mono(meth)acryloyloxyisobutyl glutanate, mono(6-(meth)acryloyloxy Liloyloxy-n-hexyl), mono(8-(meth)acryloyloxy-n-octyl) glutanoate, mono(10-(meth)acryloyloxy-n-decyl) glutanoate, mono(meth)acryloyloxyisodecyl glutanoate, mono(2-(meth)acryloyloxyethyl) adipic acid, mono(3-(meth)acryloyloxy-n-propyl) adipic acid, mono(meth)acryloyloxyisopropyl adipic acid, mono(4-(meth)acryloyloxy-n-butyl) adipic acid, mono(meth)acryloyloxyisobutyl adipic acid,Mono(6-(meth)acryloyloxy-n-hexyl) adipic acid, mono(8-(meth)acryloyloxy-n-octyl) adipic acid, mono(10-(meth)acryloyloxy-n-decyl) adipic acid, mono(meth)acryloyloxyisodecyl adipic acid, mono(2-(meth)acryloyloxyethyl) pimlic acid, mono(3-(meth)acryloyloxy-n-propyl) pimlic acid, mono(meth)acryloyloxyisopropyl pimlic acid, mono(4-(meth)acryloyloxy-n-butyl) pimlic acid, Mono(meth)acryloyloxyisobutyl pimlic acid, mono(6-(meth)acryloyloxy-n-hexyl) pimlic acid, mono(8-(meth)acryloyloxy-n-octyl) pimlic acid, mono(10-(meth)acryloyloxy-n-decyl) pimlic acid, mono(meth)acryloyloxyisodecyl pimlic acid, mono(2-(meth)acryloyloxyethyl) suberic acid, mono(3-(meth)acryloyloxy-n-propyl) suberic acid, mono(meth)acryloyloxyisopropyl suberic acid, Mono(4-(meth)acryloyloxy-n-butyl) beric acid, mono(meth)acryloyloxyisobutyl suberic acid, mono(6-(meth)acryloyloxy-n-hexyl) suberic acid, mono(8-(meth)acryloyloxy-n-octyl) suberic acid, mono(10-(meth)acryloyloxy-n-decyl) suberic acid, mono(meth)acryloyloxyisodecyl suberic acid, mono(2-(meth)acryloyloxyethyl) azelaic acid, mono(3-(meth)acryloyloxy-n-propyl) azelaic acid ), mono(meth)acryloyloxyisopropyl azelaic acid, mono(4-(meth)acryloyloxy-n-butyl) azelaic acid, mono-(meth)acryloyloxyisobutyl azelaic acid, mono(6-(meth)acryloyloxy-n-hexyl) azelaic acid, mono(8-(meth)acryloyloxy-n-octyl) azelaic acid, mono(10-(meth)acryloyloxy-n-decyl) azelaic acid, mono(meth)acryloyloxyisodecyl azelaic acid, mono(2-(meth)acryloyloxyethyl) sebacate,mono(3-(meth)acryloyloxy-n-propyl) sebacate, mono(meth)acryloyloxyisopropyl sebacate, mono(4-(meth)acryloyloxy-n-butyl) sebacate, mono(meth)acryloyloxyisobutyl sebacate, mono(6-(meth)acryloyloxy-n-hexyl) sebacate, mono(8-(meth)acryloyloxy-n-octyl) sebacate, mono(10-(meth)acryloyloxy-n-decyl) sebacate, mono(meth)acryloyloxyisodecyl sebacate, mono(2-(meth)acryloyl Dodecanediol mono(3-(meth)acryloyloxy-n-propyl), dodecanediol mono(meth)acryloyloxyisopropyl, dodecanediol mono(4-(meth)acryloyloxy-n-butyl), dodecanediol mono(meth)acryloyloxyisobutyl, dodecanediol mono(6-(meth)acryloyloxy-n-hexyl), dodecanediol mono(8-(meth)acryloyloxy-n-octyl), dodecanediol mono(10-(meth)acryloyloxy-n-decyl), dodecanediol mono(meth)acryloyloxyisodecyl, etc.

[0091] Monoesterified compounds of alkylene (C2-C4) oxide adducts (1-10 moles added) of hydroxyalkyl (C1-C10) (meth)acrylates and dicarboxylic acids with C3-C14 {for example, monoesterified compounds of malonic acid and (meth)acryloyloxyethyl polyethylene glycol (1-10 moles of ethylene oxide added), monoesterified compounds of malonic acid and (meth)acryloyloxy-n-propyl polyethylene glycol (1-10 moles of ethylene oxide added), monoesterified compounds of malonic acid and (meth)acryloyloxyisopropyl polyethylene glycol Monoesterified compounds of methyl ammonium chloride (1-10 moles of ethylene oxide added), monoesterified compounds of malonic acid and (meth)acryloyloxy-n-butyl polyethylene glycol (1-10 moles of ethylene oxide added), monoesterified compounds of malonic acid and (meth)acryloyloxyisobutyl polyethylene glycol (1-10 moles of ethylene oxide added), monoesterified compounds of succinic acid and (meth)acryloyloxyethyl polyethylene glycol (1-10 moles of ethylene oxide added), monoesterified compounds of succinic acid and (meth)acryloyloxy-n-propyl Monoesterified polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified succinic acid with (meth)acryloyloxyisopropyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified succinic acid with (meth)acryloyloxy-n-butyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified succinic acid with (meth)acryloyloxyisobutyl polyethylene glycol (with 1-10 moles of ethylene oxide added), and glutanic acid with (meth)acryloyloxyisopropyl polyethylene glycol. Monoesterified glutanoic acid with hydroxyethyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified glutanoic acid with (meth)acryloyloxy-n-propyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified glutanoic acid with (meth)acryloyloxyisopropyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified glutanoic acid with (meth)acryloyloxy-n-butyl polyethylene glycol (with 1-10 moles of ethylene oxide added),Monoesterified glutanic acid with (meth)acryloyloxyisobutyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified adipic acid with (meth)acryloyloxyethyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified adipic acid with meth)acryloyloxy-n-propyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified adipic acid with meth)acryloyloxyisopropyl polyethylene glycol (with 1-10 moles of ethylene oxide added) Monoesterified with ), monoesterified with adipic acid and (meth)acryloyloxy-n-butyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified with adipic acid and (meth)acryloyloxyisobutyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified with pimlic acid and (meth)acryloyloxyethyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified with pimlic acid and (meth)acryloyloxy-n-propyl polyethylene glycol ( Monoesterified with (1-10 moles of ethylene oxide added), monoesterified with (meth)acryloyloxyisopropyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified with (meth)acryloyloxy-n-butyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified with (meth)acryloyloxyisobutyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified with suberic acid and (meth)acryloyloxy Monoesterified ethyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified suberic acid with (meth)acryloyloxy-n-propyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified suberic acid with (meth)acryloyloxyisopropyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified suberic acid with (meth)acryloyloxy-n-butyl polyethylene glycol (with 1-10 moles of ethylene oxide added),Monoesterified suberic acid with (meth)acryloyloxyisobutyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified azelaic acid with (meth)acryloyloxyethyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified azelaic acid with (meth)acryloyloxy-n-propyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified azelaic acid with (meth)acryloyloxyisopropyl polyethylene glycol (with 1-10 moles of ethylene oxide added). Monoesterified with (10 mol addition), monoesterified azelaic acid and (meth)acryloyloxy-n-butyl polyethylene glycol (1-10 mol addition of ethylene oxide), monoesterified azelaic acid and (meth)acryloyloxyisobutyl polyethylene glycol (1-10 mol addition of ethylene oxide), monoesterified sebacic acid and (meth)acryloyloxyethyl polyethylene glycol (1-10 mol addition of ethylene oxide), monoesterified sebacic acid and (meth)acryloyloxy-n-propyl polyethylene glycol Monoesterified sebacic acid with (1-10 moles of ethylene oxide added), monoesterified sebacic acid with (meth)acryloyloxyisopropyl polyethylene glycol (1-10 moles of ethylene oxide added), monoesterified sebacic acid with (meth)acryloyloxy-n-butyl polyethylene glycol (1-10 moles of ethylene oxide added), monoesterified sebacic acid with (meth)acryloyloxyisobutyl polyethylene glycol (1-10 moles of ethylene oxide added), and dodecanediic acid with (meth)acryloyl Monoesterified oxyethyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified dodecanediic acid and (meth)acryloyloxy-n-propyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified dodecanediic acid and (meth)acryloyloxyisopropyl polyethylene glycol (with 1-10 moles of ethylene oxide added), monoesterified dodecanediic acid and (meth)acryloyloxy-n-butyl polyethylene glycol (with 1-10 moles of ethylene oxide added),Examples include monoesterified compounds of dodecanediic acid and (meth)acryloyloxyisobutyl polyethylene glycol (with 1 to 10 moles of ethylene oxide added).

[0092] Monomer (t1) can be obtained, for example, by monoesterification of an alkyl dicarboxylic acid having 3 to 14 carbon atoms (e.g., malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and alkyl (1 to 10 carbon atoms) succinic acid, etc.) or their anhydrides or lower alkyl (1 to 4 carbon atoms) esters with hydroxyalkyl (1 to 10 carbon atoms) (meth)acrylate or a 1 to 10 molar adduct of hydroxyalkyl (1 to 10 carbon atoms) (meth)acrylate. Alternatively, it can be obtained by monoesterification of an alkyl dicarboxylic acid having 3 to 14 carbon atoms or their anhydrides or lower alkyl (1 to 4 carbon atoms) esters with hydroxyalkyl (1 to 10 carbon atoms) (meth)acrylamide or a 1 to 10 molar adduct of hydroxyalkyl (1 to 10 carbon atoms) (meth)acrylamide. Furthermore, monomers (t1) such as mono(2-acryloyloxyethyl) succinate (manufactured by Tokyo Chemical Industry Co., Ltd.) and mono(2-acryloyloxyethyl) succinate (product name "HOA-MS(N)", manufactured by Kyoeisha Chemical Co., Ltd.) are commercially available and can be obtained.

[0093] The monomer (t2) is a monomer having 1 to 5 carboxyl groups, represented by the general formula (5) above. R in general formula (5) 12 This is either a hydrogen atom or a methyl group, and of these, both hydrogen atoms and methyl groups are preferred from the viewpoint of wear prevention.

[0094] -X in general formula (5) 7 - represents a group represented by -O- or NH-, of which -O- is preferred from the viewpoint of wear prevention.

[0095] R in general formula (5) 13is an alkylene group having 1 to 10 carbon atoms. Examples of the alkylene group having 1 to 10 carbon atoms include a methylene group, an ethylene group, an isopropylene group, a 1,2- or 1,3-propylene group, an isobutylene group, a 1,2-, 1,3- or 1,4-butylene group, an isopentylene group, a 1,2-, 1,3-, 1,4- or 1,5-pentylene group, an isohexylene group, a 1,2-, 1,3-, 1,4-, 1,5- or 1,6-hexylene group, an isoheptylene group, a 1,2-, 1,3-, 1,4-, 1,5-, 1,6- or 1,7-heptylene group, an isooctylene, a 1,8-octylene group, an isononylene group, a 1,9-nonylene group, an isodecylene group, a 1,10-decylene group, and the like. Among these, from the viewpoint of antiwear properties, an ethylene group, a 1,2-propylene group, and a 1,3-propylene group are preferable, and an ethylene group is more preferable.

[0096] R in the general formula (5) 14 O is an alkyleneoxy group having 2 to 4 carbon atoms. Examples of the alkyleneoxy group having 2 to 4 carbon atoms include an ethyleneoxy group, a propyleneoxy group, and a butyleneoxy group. Examples of the propylene group in the propyleneoxy group include a 1,2-propylene group and a 1,3-propylene group, and examples of the butylene group in the butyleneoxy group include a 1,2-butylene group, a 1,3-butylene group, and a 1,4-butylene group. As the alkyleneoxy group, from the viewpoint of antiwear properties, an ethyleneoxy group and a propyleneoxy group are preferable, and an ethyleneoxy group is more preferable.

[0097] v in the general formula (5) is an integer of 0 to 10, preferably an integer of 0 to 7, more preferably an integer of 0 to 5, and particularly preferably an integer of 0 to 3 from the viewpoint of antiwear properties. When v is 2 or more, a plurality of R 14 O may be the same or different.

[0098] R in the general formula (5) 15Each of these is independently a hydrogen atom or a carboxyl group, with at least one being a carboxyl group. Of these, from the viewpoint of wear prevention, there are preferably 1 to 5 carboxyl groups, more preferably 1 to 4 carboxyl groups, and particularly preferably 1 to 3.

[0099] Specific examples of monomers (t2) include monohydroxyethyl (meth)acrylate phthalate, monohydroxy-n-propyl (meth)acrylate phthalate, monohydroxyisopropyl (meth)acrylate phthalate, monohydroxy-n-butyl (meth)acrylate phthalate, monohydroxyisobutyl (meth)acrylate phthalate, monohydroxy-n-hexyl (meth)acrylate phthalate, monohydroxy-n-octyl (meth)acrylate phthalate, monohydroxy-n-decyl (meth)acrylate phthalate, and phthalates. Monoesterified hydroxyalkyl (C2-C10) (meth)acrylates with 1-10 molar alkylene (C2-C4) oxide adducts, monohydroxyethyl (meth)acrylate trimellitate, monohydroxy-n-propyl (meth)acrylate trimellitate, monohydroxyisopropyl (meth)acrylate trimellitate, monohydroxy-n-butyl (meth)acrylate trimellitate, monohydroxyisobutyl (meth)acrylate trimellitate, monohydroxy-n-hexyl (meth)acrylate trimellitate Crylate, monohydroxy-n-octyl (meth)acrylate trimellitic acid, monohydroxy-n-decyl (meth)acrylate trimellitic acid, monoesterified trimellitic acid with 1-10 molar alkylene (2-4 carbon atoms) oxide adducts of hydroxyalkyl (2-10 carbon atoms) (meth)acrylate, monohydroxyethyl (meth)acrylate pyromellitic acid, monohydroxy-n-propyl (meth)acrylate pyromellitic acid, monohydroxyisopropyl (meth)acrylate pyromellitic acid, monohydroxy -n-butyl (meth)acrylate, pyromelidic acid monohydroxyisobutyl (meth)acrylate, pyromelidic acid monohydroxy-n-hexyl (meth)acrylate, pyromelidic acid monohydroxy-n-octyl (meth)acrylate, pyromelidic acid monohydroxy-n-decyl (meth)acrylate, monoesterified pyromelidic acid with 1-10 molar alkylene (carbon 2-4) oxide adducts of hydroxyalkyl (carbon 2-10) (meth)acrylate, benzenepentacarboxylic acid monohydroxyethyl (meth)acrylate,Monohydroxy-n-propyl (meth)acrylate of benzenepentacarboxylic acid, monohydroxyisopropyl (meth)acrylate of benzenepentacarboxylic acid, monohydroxy-n-butyl (meth)acrylate of benzenepentacarboxylic acid, monohydroxyisobutyl (meth)acrylate of benzenepentacarboxylic acid, monohydroxy-n-hexyl (meth)acrylate of benzenepentacarboxylic acid, monohydroxy-n-octyl (meth)acrylate of benzenepentacarboxylic acid, monohydroxy-n-decyl (meth)acrylate of benzenepentacarboxylic acid, alkylene (2-4 carbon atoms) oxides 1-10 of benzenepentacarboxylic acid and hydroxyalkyl (2-10 carbon atoms) (meth)acrylates Examples include monoesterified products with molar adducts, monohydroxyethyl (meth)acrylate of mellitate, monohydroxy-n-propyl (meth)acrylate of mellitate, monohydroxyisopropyl (meth)acrylate of mellitate, monohydroxy-n-butyl (meth)acrylate of mellitate, monohydroxyisobutyl (meth)acrylate of mellitate, monohydroxy-n-hexyl (meth)acrylate of mellitate, monohydroxy-n-octyl (meth)acrylate of mellitate, monohydroxy-n-decyl (meth)acrylate of mellitate, and monoesterified products of mellitate and hydroxyalkyl (C2-C10) (meth)acrylate with 1-10 molar adducts of alkylene (C2-C4) oxide.

[0100] Monomer (t2) can be obtained, for example, by monoesterification of aromatic polyvalent (2-6 valent) carboxylic acids (e.g., phthalic acid, isophthalic acid, terephthalic acid, hemimellitic acid, trimellitic acid, trimesic acid, merophanic acid, prenitic acid, pyromellitic acid, and melitic acid, etc.) or their anhydrides or lower alkyl (C1-4) esters with hydroxyalkyl (C1-10) (meth)acrylate or a 1-10 molar adduct of hydroxyalkyl (C1-10) (meth)acrylate with alkylene (C2-4) oxide. Alternatively, it can be obtained by monoesterification of aromatic polyvalent (2-6 valent) carboxylic acids or their anhydrides or lower alkyl (C1-4) esters with hydroxyalkyl (C1-10) (meth)acrylamide or a 1-10 molar adduct of hydroxyalkyl (C1-10) (meth)acrylamide with alkylene (C2-4) oxide. Furthermore, monomers (t2) such as mono(2-methacryloyloxyethyl) phthalate (manufactured by Tokyo Chemical Industry Co., Ltd.) and mono(2-acryloyloxyethyl) phthalate (product name "HOA-MPL(N)", manufactured by Kyoeisha Chemical Co., Ltd.) are commercially available and can be obtained.

[0101] Monomer (t3) is a monomer having 1 to 5 carboxyl groups, represented by the general formula (6) above. R in general formula (6) 16 This is either a hydrogen atom or a methyl group, and of these, both hydrogen atoms and methyl groups are preferred from the viewpoint of wear prevention.

[0102] -X in general formula (6) 8 - represents a group represented by -O- or NH-, of which -O- is preferred from the viewpoint of wear prevention.

[0103] R in general formula (6) 17 This is an alkylene group having 1 to 10 carbon atoms. Examples of alkylene groups having 1 to 10 carbon atoms include methylene, ethylene, isopropylene, 1,2- or 1,3-propylene, isobutylene, 1,2-, 1,3- or 1,4-butylene, isopentylene, 1,2-, 1,3-, 1,4- or 1,5-pentylene, isohexylene, 1,2-, 1,3-, 1,4-, 1,5- or 1,6-hexylene, isoheptylene, 1,2-, 1,3-, 1,4-, 1,5-, 1,6- or 1,7-heptylene, isooctylene, 1,8-octylene, isononylene, 1,9-nonylene, isodecylene, and 1,10-decylene. Of these, ethylene groups, 1,2-propylene groups, and 1,3-propylene groups are preferred from the viewpoint of wear prevention, and ethylene groups are more preferred.

[0104] R in general formula (6) 18 O is an alkylene oxy group having 2 to 4 carbon atoms. Examples of alkylene oxy groups having 2 to 4 carbon atoms include ethylene oxy group, propylene oxy group, and butylene oxy group. Examples of propylene groups in the propylene oxy group include 1,2-propylene group and 1,3-propylene group, and examples of butylene groups in the butylene oxy group include 1,2-butylene group, 1,3-butylene group, and 1,4-butylene group. From the viewpoint of wear prevention, the alkylene oxy group is preferably an ethylene oxy group and a propylene oxy group, and more preferably an ethylene oxy group.

[0105] In general formula (6), r is an integer between 0 and 10, preferably an integer between 0 and 7, more preferably an integer between 0 and 5, and particularly preferably an integer between 0 and 3, from the viewpoint of wear prevention. If r is 2 or greater, there are multiple R 18 O can be the same or different.

[0106] R in general formula (6) 19Each of these is independently a hydrogen atom or a carboxyl group, with at least one being a carboxyl group. Of these, from the viewpoint of wear prevention, there are preferably 1 to 5 carboxyl groups, more preferably 1 to 4 carboxyl groups, and particularly preferably 1 to 3. Specific examples of monomers (t3) include monohydroxyethyl (meth)acrylate hexahydrophthalate, monohydroxy-n-propyl (meth)acrylate hexahydrophthalate, monohydroxyisopropyl (meth)acrylate hexahydrophthalate, monohydroxy-n-butyl (meth)acrylate hexahydrophthalate, monohydroxyisobutyl (meth)acrylate hexahydrophthalate, monohydroxy-n-hexyl (meth)acrylate hexahydrophthalate, and monohydroxy-n-octyl (meth)acrylate hexahydrophthalate. Rate, monohydroxy-n-decyl (meth)acrylate hexahydrophthalate, monoesterified hexahydrophthalate with 1-10 molar alkylene (2-4 carbon atoms) oxide adducts of hydroxyalkyl (1-10 carbon atoms) (meth)acrylate, monohydroxyethyl (meth)acrylate 1,2,4-cyclohexanetricarboxylic acid, monohydroxy-n-propyl (meth)acrylate 1,2,4-cyclohexanetricarboxylic acid, monohydroxyisopropyl (meth)acrylate 1,2 ,4-cyclohexanetricarboxylic acid monohydroxy-n-butyl (meth)acrylate, 1,2,4-cyclohexanetricarboxylic acid monohydroxyisobutyl (meth)acrylate, 1,2,4-cyclohexanetricarboxylic acid monohydroxy-n-hexyl (meth)acrylate, 1,2,4-cyclohexanetricarboxylic acid monohydroxy-n-octyl (meth)acrylate, 1,2,4-cyclohexanetricarboxylic acid monohydroxy-n-decyl (meth)acrylate, 1,2,4-cyclohexanetricarboxylic acid and hydroxyalkyl ( Monoesterified compounds of C1-C10 (meth)acrylates with 1-10 molar alkylene (C2-C4) oxide adducts, 1,2,4,5-cyclohexanetetracarboxylic acid monohydroxyethyl (meth)acrylate, 1,2,4,5-cyclohexanetetracarboxylic acid monohydroxy-n-propyl (meth)acrylate, 1,2,4,5-cyclohexanetetracarboxylic acid monohydroxyisopropyl (meth)acrylate, 1,2,4,5-cyclohexanetetracarboxylic acid monohydroxy-n-butyl (meth)acrylate, 1,2,4,Monohydroxyisobutyl (meth)acrylate of 5-cyclohexanetetracarboxylic acid, monohydroxy-n-hexyl (meth)acrylate of 1,2,4,5-cyclohexanetetracarboxylic acid, monohydroxy-n-octyl (meth)acrylate of 1,2,4,5-cyclohexanetetracarboxylic acid, monohydroxy-n-decyl (meth)acrylate of 1,2,4,5-cyclohexanetetracarboxylic acid, alkylenes of 1,2,4,5-cyclohexanetetracarboxylic acid and hydroxyalkyl (C1-C10) (meth)acrylates. Monoesterified with 1-10 molar oxide adducts (2-4 carbon atoms), 1,2,3,4,5-cyclohexanepentacarboxylic acid monohydroxyethyl (meth)acrylate, 1,2,3,4,5-cyclohexanepentacarboxylic acid monohydroxy-n-propyl (meth)acrylate, 1,2,3,4,5-cyclohexanepentacarboxylic acid monohydroxyisopropyl (meth)acrylate, 1,2,3,4,5-cyclohexanepentacarboxylic acid monohydroxy-n-butyl (meth)acrylate, 1,2,3,4,5-cyclohexane Monohydroxyisobutyl (meth)acrylate pentacarboxylic acid, monohydroxy-n-hexyl (meth)acrylate 1,2,3,4,5-cyclohexanepentacarboxylic acid, monohydroxy-n-octyl (meth)acrylate 1,2,3,4,5-cyclohexanepentacarboxylic acid, monohydroxy-n-decyl (meth)acrylate 1,2,3,4,5-cyclohexanepentacarboxylic acid, alkylene (carbon) alkyl (carbon) alkyl (carbon) alkyl (carbon) alkyl (carbon) alkyl (carbon) alkyl (carbon) alkyl (carbon) alkyl (carbon) alkyl (carbon) alkyl (carbon) alkyl (carbon) Monoesterified with 1-10 molar oxide adducts of prime numbers 2-4, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid monohydroxyethyl (meth)acrylate, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid monohydroxy-n-propyl (meth)acrylate, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid monohydroxyisopropyl (meth)acrylate, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid monohydroxy-n-butyl (meth)acrylate, 1,2,3,4,5,Examples include monohydroxyisobutyl (meth)acrylate of 6-cyclohexanehexacarboxylic acid, monohydroxy-n-hexyl (meth)acrylate of 1,2,3,4,5,6-cyclohexanehexacarboxylic acid, monohydroxy-n-octyl (meth)acrylate of 1,2,3,4,5,6-cyclohexanehexacarboxylic acid, monohydroxy-n-decyl (meth)acrylate of 1,2,3,4,5,6-cyclohexanehexacarboxylic acid, and monoesters of 1,2,3,4,5,6-cyclohexanehexacarboxylic acid with 1 to 10 molar adducts of alkylene (carbon 2 to carbon 4) oxides of hydroxyalkyl (carbon 1 to carbon 10) (meth)acrylate.

[0107] The monomer (t3) is, for example, a cyclohexane polyvalent (2-6 valent) carboxylic acid (e.g., 1,2-cyclohexanedicarboxylic acid (also written as hexahydrophthalic acid), 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,2,3-cyclohexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,3,5-cyclohexanetricarboxylic acid, 1,2,3,4-cyclohexanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid It can be obtained by monoesterification of an acid (such as 1,2,3,5-cyclohexanetetracarboxylic acid, 1,2,3,4,5-cyclohexanepentacarboxylic acid, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid, etc.) or their anhydrides or lower alkyl (C1-C4) esters with hydroxyalkyl (C1-C10) (meth)acrylate or a 1-10 molar adduct of hydroxyalkyl (C1-C10) (meth)acrylate and alkylene (C2-C4) oxide. Alternatively, it can be obtained by monoesterification of a polyvalent cyclohexane or its anhydrides or lower alkyl (C1-C4) esters with hydroxyalkyl (C1-C10) (meth)acrylamide or a 1-10 molar adduct of hydroxyalkyl (C1-C10) (meth)acrylamide and alkylene (C2-C4) oxide. Furthermore, monomers (t3) such as mono(2-methacryloyloxyethyl) hexahydrophthalate (manufactured by Tokyo Chemical Industry Co., Ltd.) and mono(2-acryloyloxyethyl) hexahydrophthalate (product name "Light Acrylate HOA-HH(N)", manufactured by Kyoeisha Chemical Co., Ltd.) are commercially available and can be obtained.

[0108] The weight percentage of monomer (a) constituting copolymer (A) is preferably 10 to 45% by weight, more preferably 18 to 40% by weight, then even more preferably 22 to 36% by weight, and particularly preferably 28 to 36% by weight, based on the total weight of the constituent monomers of (A), from the viewpoint of base oil solubility and wear prevention properties. The weight percentage of monomer (b) constituting copolymer (A) is preferably 0.5 to 20% by weight, more preferably 2 to 15% by weight, then even more preferably 2 to 10% by weight, and particularly preferably 3 to 10% by weight, based on the total weight of the constituent monomers of (A), from the viewpoint of wear resistance, low copper corrosion resistance, and electrical insulation. The weight percentage of monomer (c) constituting copolymer (A) is preferably 50 to 85% by weight, more preferably 53 to 75% by weight, even more preferably 53 to 70% by weight, then even more preferably 55 to 67% by weight, and particularly preferably 58 to 67% by weight, based on the total weight of the constituent monomers of (A), from the viewpoint of base oil solubility and wear prevention. The weight percentage of monomers (t) constituting the copolymer (A) is preferably 0.5 to 17.5% by weight, more preferably 1.5 to 13% by weight, then even more preferably 1.5 to 10% by weight, and particularly preferably 3 to 10% by weight, based on the total weight of the constituent monomers of (A), from the viewpoint of wear resistance, low copper corrosion resistance, and electrical insulation. From the viewpoint of wear prevention, the total weight percentage of monomers (d) to (f) constituting copolymer (A) is preferably 20% by weight or less, more preferably 15% by weight or less, then even more preferably 10% by weight or less, and particularly preferably 7% by weight or less, based on the total weight of the constituent monomers of (A). From the viewpoint of wear prevention, the total weight percentage of monomers (g) to (n) constituting copolymer (A) is preferably 10% by weight or less, more preferably 7% by weight or less, and particularly preferably 5% by weight or less, based on the total weight of the constituent monomers of (A).

[0109] In the present invention, the weight ratio (a / b) of monomer (a) to the weight of monomer (b) in the copolymer (A) is 0.5 to 80. A weight ratio (a / b) of 0.5 or higher results in good copper compatibility (low copper corrosion) and electrical insulation, while a ratio of 80 or lower provides excellent wear prevention. In this invention, by containing monomer (a) and monomer (b) as constituent monomers in the above weight ratio in copolymer (A), copper corrosion is suppressed, while the carboxyl group derived from monomer (b) enhances the adsorption force to the metal, and the side chain {-(-C(=O)-R} derived from monomer (a) 2 -X 3 -) p -R 3 It is presumed that this, combined with the adhesive force provided by the} portion, can further enhance the wear prevention effect. The weight ratio (a / b) is preferably 0.5 to 20, more preferably 1 to 10, and particularly preferably 2 to 8.

[0110] In the present invention, the total weight ratio of monomers (a) and monomer (b) constituting copolymer (A) is preferably 15 to 50% by weight, more preferably 25 to 47% by weight, even more preferably 30 to 42% by weight, and particularly preferably 33 to 40% by weight, based on the total weight of the constituent monomers of (A), from the viewpoint of base oil solubility and wear prevention properties. In the present invention, the total weight ratio of monomers (a), monomer (b), and monomer (c) constituting copolymer (A) is preferably 83% by weight or more, more preferably 87% by weight or more, and particularly preferably 95% by weight or more, from the viewpoint of wear prevention.

[0111] The acid value of copolymer (A) is preferably 1.0 to 38 mg KOH / g, more preferably 3.8 to 28 mg KOH / g, and particularly preferably 5.8 to 19 mg KOH / g, from the viewpoint of wear prevention, low copper corrosion, and electrical insulation. The acid value of (A) can be measured in accordance with JIS K2501.

[0112] The SP value of copolymer (A) is 8.5 to 11.5 (cal / cm²) from the viewpoint of base oil solubility and viscosity index improvement effect. 3 ) 1 / 2 Preferably, and more preferably 8.7 to 11.0 (cal / cm³). 3 ) 1 / 2 , more preferably 8.9~10.5 (cal / cm³) 3 ) 1 / 2 And, particularly preferably, 9.2 to 10.2 (cal / cm²). 3 ) 1 / 2 That is the case.

[0113] The SP value of copolymer (A) is calculated by determining the SP value of the constituent units derived from each monomer constituting (A) using the SP value calculation method described above (the structure in which the vinyl groups contained in each monomer constituting (A) become single bonds through polymerization reactions), and then taking the arithmetic mean value based on the weight fraction of each constituent monomer at the time of preparation. For example, if the monomer is methyl methacrylate, the constituent units derived from methyl methacrylate consist of two CH3 groups, one CH2 group, one C group, and one CO2 group. Therefore, according to the following formula, the SP value of the constituent units derived from methyl methacrylate is 9.933 (cal / cm³). 3 ) 1 / 2 It can be seen that... Similarly, calculating, the SP value of the constituent unit derived from ethyl methacrylate is 9.721 (cal / cm³). 3 ) 1 / 2 It can be seen that this is the case. ΣΔe i =1125×2+1180+350+4300=8080 Σv i =33.5 × 2 + 16.1 - 19.2 + 18.0 = 81.9 δ = (8080 / 81.9) 1 / 2 = 9.933 (cal / cm3 ) 1 / 2 When the polymer is a polymer of 50% by weight methyl methacrylate and 50% by weight ethyl methacrylate, the SP value of the polymer is calculated by taking the arithmetic mean based on the weight fraction of the SP values ​​of the constituent units derived from each monomer, as shown below. SP value of polymer = (9.933 × 50 + 9.721 × 50) / 100 = 9.827 (cal / cm²) 3 ) 1 / 2 The SP value of polymer (A) can be adjusted to a desired range by appropriately adjusting the monomers and their weight fractions used. Specifically, the SP value can be reduced by using a large amount of monomers with long alkyl groups, and increased by using a large amount of monomers with short alkyl groups.

[0114] The weight-average molecular weight (hereinafter abbreviated as Mw) of copolymer (A) is preferably 0.5 million to 500,000, more preferably 0.5 million to 100,000, and particularly preferably 10,000 to 50,000, from the viewpoint of wear prevention.

[0115] Copolymer (A) can be obtained by known manufacturing methods, specifically by solution polymerization of the monomer in a solvent in the presence of a polymerization catalyst. Examples of solvents include toluene, xylene, alkylbenzenes having 9 to 10 carbon atoms, methyl ethyl ketone, ethyl acetate, 2-propanol, and base oils described later. Polymerization catalysts include azo catalysts (such as azobisisobutyronitrile and azobisvaleronitrile), peroxide catalysts (such as benzoyl peroxide, cumyl peroxide, and lauryl peroxide), and redox catalysts (such as a mixture of benzoyl peroxide and a tertiary amine). Furthermore, known chain transfer agents (such as alkyl mercaptans with 2 to 20 carbon atoms) can be used as needed. The polymerization temperature is preferably 25 to 140°C, and more preferably 50 to 120°C. In addition to the above solution polymerization, (A) can also be obtained by bulk polymerization, emulsion polymerization, or suspension polymerization. The polymerization form of copolymer (A) may be either a random addition copolymer or an alternating copolymer, and may also be either a graft copolymer or a block copolymer.

[0116] The anti-wear agent of the present invention may contain the copolymer (A), but may also contain a base oil from the viewpoint of handling (ease of addition to lubricating oil composition, etc.). Examples of base oils include mineral oils (solvent-refined oils, paraffin oils, high viscosity index oils containing isoparaffins, high viscosity index oils obtained by hydrocracking of isoparaffins, and naphthenic oils, etc.), synthetic lubricants [hydrocarbon-based synthetic lubricants (poly-α-olefin-based synthetic lubricants, etc.) and ester-based synthetic lubricants, etc.], and mixtures thereof. Of these, mineral oils and hydrocarbon-based synthetic lubricants are preferred from the viewpoint of electrical insulation.

[0117] The content of copolymer (A) in the anti-wear agent is preferably 20 to 90% by weight, and more preferably 30 to 80% by weight, based on the weight of the anti-wear agent, from the viewpoint of handling (ease of addition to lubricating oil composition, etc.). The base oil content in the anti-wear agent is preferably 10 to 80% by weight, and more preferably 20 to 70% by weight, based on the weight of the anti-wear agent, from the viewpoint of handling (ease of addition to lubricating oil composition, etc.).

[0118] The anti-wear agent of the present invention has low copper corrosiveness and high anti-wear effect, and is therefore suitably used in gear oil (differential oil and industrial gear oil, etc.), MTF, transmission oil [ATF and belt-CVTF, etc.], traction oil (toroidal-CVT F, etc.), shock absorber oil, power steering oil, hydraulic oil (hydraulic oil for construction machinery and industrial hydraulic oil, etc.), and engine oil, and is preferably used as an anti-wear agent for transmission oil, electric motor oil, and dual-purpose oil for transmissions and electric motors in electric vehicles or hybrid vehicles, and is particularly preferably used as an anti-wear agent for dual-purpose oil for transmissions and electric motors in electric vehicles or hybrid vehicles.

[0119] <Lubricating oil composition> The lubricating oil composition of the present invention contains the anti-wear agent and base oil of the present invention. If the anti-wear agent contains a base oil, the same base oil as the base oil in the anti-wear agent may be used, or a different base oil may be used. Examples of base oils used in lubricating oil compositions include mineral oils (solvent-refined oils, paraffin oils, high viscosity index oils containing isoparaffins, high viscosity index oils obtained by hydrocracking of isoparaffins, and naphthenic oils, etc.), synthetic lubricating oils [hydrocarbon-based synthetic lubricating oils (poly-α-olefin-based synthetic lubricating oils, etc.) and ester-based synthetic lubricating oils, etc.] and mixtures thereof. Of these, mineral oils and hydrocarbon-based synthetic lubricating oils are preferred from the viewpoint of insulating properties.

[0120] The kinematic viscosity of the base oil at 100°C (measured according to JIS-K2283) is preferably 1 to 10 mm from the viewpoint of the solubility of copolymer (A). 2 / s, and more preferably 1-4 mm 2 It is / s. The viscosity index of the base oil (measured according to JIS-K2283) is preferably 90 or higher, and more preferably 100 or higher, from the viewpoint of improving the viscosity index.

[0121] The cloud point of the base oil (measured according to JIS-K2269) is preferably -5°C or lower, and more preferably -15°C or lower. When the cloud point of the base oil is within this range, the low-temperature viscosity of the lubricating oil composition is good.

[0122] From the viewpoint of compatibility, the absolute value (ΔSP) of the difference between the SP value of copolymer (A) in the lubricating oil composition and the SP value of the base oil is preferably 0.5 to 3.2 (cal / cm³). 3 ) 1 / 2 And more preferably 0.6 to 2.5 (cal / cm²). 3 ) 1 / 2 Particularly preferred is 0.6 to 2.1 (cal / cm³). 3 ) 1 / 2 And most preferably 0.7 to 1.7 (cal / cm²). 3 ) 1 / 2 That is the case.

[0123] The content of copolymer (A) in the lubricating oil composition of the present invention is preferably 0.1 to 30% by weight, more preferably 0.1 to 20% by weight, and particularly preferably 0.1 to 10% by weight, based on the weight of the lubricating oil composition, from the viewpoint of wear prevention.

[0124] The lubricating oil composition of the present invention is suitably used in gear oil (differential oil and industrial gear oil, etc.), MTF, transmission oil [ATF and belt-CVTF, etc.], traction oil (toroidal-CVT F, etc.), shock absorber oil, power steering oil, hydraulic oil (hydraulic oil for construction machinery and industrial hydraulic oil, etc.), and engine oil, and is preferably useful as transmission oil, electric motor oil, or dual-purpose oil for transmissions and electric motors in electric vehicles or hybrid vehicles, and is particularly preferably useful as a dual-purpose oil for transmissions and electric motors in electric vehicles or hybrid vehicles.

[0125] The lubricating oil composition of the present invention may contain various other additives besides the anti-wear agent of the present invention. Examples of other additives include at least one selected from the group consisting of viscosity index improvers, detergents, dispersants, antioxidants, oiliness improvers, extreme pressure agents, defoamers, anti-emulsifiers, corrosion inhibitors, and pour point depressants, and examples of each additive are as follows. Alternatively, multiple additives may be included in the lubricating oil composition as a lubricating oil package additive. Examples of lubricating oil package additives include DI (Detergent Inhibitor) packages. DI packages are commercially available and can be obtained from companies such as Lubrizol Corporation (for example, the LUBRIZOL PV series for gasoline vehicles, product name PV1510, etc.), Infinium (for example, Infinium P5741 for engine oil, etc.), Chevron Corporation (for example, OLOA55501, OLOA55503, etc. for passenger car motor oils), and Afton Chemical Corporation (for example, the HiTEC 9800 series for engine oil, etc.).

[0126] (1) Viscosity index improvers: (C1-7) alkyl(meth)acrylate / (C8-40) linear or branched alkyl(meth)acrylate copolymer, dispersed monomer (amine monomer, etc.) / (C1-7) alkyl(meth)acrylate / (C8-40) linear or branched alkyl(meth)acrylate copolymer, hydroxyl group-containing monomer / (C1-7) alkyl(meth)acrylate / (C8-40) linear or branched alkyl(meth)acrylate copolymer, comb-shaped polymer [(C1-7) alkyl( [meth)acrylate / (C8-40) linear or branched alkyl (meth)acrylate / polyolefin macromonomer], ethylene / (C1-18) alkyl (meth)acrylate copolymer, alkoxyalkyl (meth)acrylate / polybutylene copolymer macromonomer / (C1-32) linear or branched alkyl (meth)acrylate copolymer, polyisobutylene, polyalkylstyrene, ethylene / propylene copolymer, styrene / maleic acid ester copolymer, styrene / isoprene hydrogenated copolymer, etc.; (2) Cleansing agent: Basic, overbasic, or neutral metal salts [overbasic sulfonates (petroleum sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, etc.) or alkaline earth metal salts, etc.], salicylates, phenates, naphthenates, carbonates, phosphonates, and mixtures thereof; (3) Dispersant: Succinimides (bis- or mono-polybutenyl succinimides), Mannich condensates, borates, etc.; (4) Antioxidants: Hindered phenols and aromatic secondary amines, etc. (5) Oiliness improvers: Long-chain fatty acids and their esters (oleic acid and oleic acid esters, etc.), long-chain amines and their amides (oleylamine and oleylamide, etc.), etc. (6) Extreme pressure agents: Sulfur compounds (mono- or disulfide, sulfoxide, and sulfur phosphide compounds), phosphide compounds, and chlorine compounds (such as chlorinated paraffins); (7) Antifoaming agent: Silicone oils, metallic soaps, fatty acid esters, and phosphate compounds, etc. (8) Antiemulsifiers: Quaternary ammonium salts (such as tetraalkylammonium salts), sulfated oils, and phosphates (such as phosphates of polyoxyethylene-containing nonionic surfactants), etc. (9) Corrosion inhibitors: Nitrogen atom-containing compounds (such as benzotriazole and 1,3,4-thiodiazolyl-2,5-bisdialkyldithiocarbamate), etc. (10) Pour point depressants: Polyalkyl methacrylate, polyalkyl acrylate, polyalkylstyrene, polyvinyl acetate, etc.

[0127] The lubricating oil composition of the present invention may contain friction and wear inhibitors other than the wear inhibitor of the present invention. (11) Friction and wear modifiers: Molybdenum-based and zinc-based compounds (such as molybdenum dithiophosphate, molybdenum dithiocarbamate, and zinc dialkyldithiophosphate);

[0128] The total content of other additives in the lubricating oil composition is preferably 0.1 to 30% by weight, more preferably 0.3 to 20% by weight, and even more preferably 3 to 10% by weight, based on the weight of the lubricating oil composition. [Examples]

[0129] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0130] <Manufacturing Example 1> [Manufacturing of Monomer (a-1)] In a reaction vessel equipped with a temperature controller, stirring blades, vacuum device, Liebig condenser, fractionation column, distillate receiving flask, nitrogen inlet and outlet, 260.3 parts by weight (2.0 mol) of 2-hydroxyethyl methacrylate (hereinafter abbreviated as HEMA), 684.8 parts by weight (6.0 mol) of ε-caprolactone, 3.7 parts by weight (0.03 mol) of hydroquinone monomethyl ether, and 0.27 parts by weight of butyltris(2-ethylhexanoyloxy)tin were added, and the mixture was heated to 115°C while stirring with air flowing through it. The reaction was then carried out at 115°C for 8 hours, and the distillate water was separated. The mixture was then cooled to 25°C, 1 The esterified product was confirmed by 1H-NMR (yield 100 mol%). (a-1) In general formula (1), A is a methacryloyl group, -X 1 -, -X 2 - and -X 3 - represents a group represented as -O-, R 1 is an ethylene group, the molar mean of p = 3, R 2 = Pentylene group, R 3 It is a monomer represented by a hydrogen atom, and its SP value is 11.04.

[0131] <Manufacturing Example 2> [Manufacturing of Monomer (a-2)] In a reaction vessel equipped with a temperature controller, stirring blades, vacuum device, Liebig condenser, fractionation column, distillate receiving flask, nitrogen inlet and outlet, 260.3 parts by weight (2.0 moles) of 2-hydroxyethyl methacrylate (HEMA), 913.2 parts by weight (8.0 moles) of ε-caprolactone, 3.7 parts by weight (0.03 moles) of hydroquinone monomethyl ether, and 0.27 parts by weight of butyltris(2-ethylhexanoyloxy)tin were added, and the mixture was heated to 115°C while stirring with air flowing through. The reaction was then carried out at 115°C for 8 hours, and the distillate was separated. The mixture was then cooled to 25°C, 1 The esterified product was confirmed by 1H-NMR (yield 100 mol%). (a-2) is where A in general formula (1) is a methacryloyl group, and -X 1 -, -X 2 - and -X 3 - represents a group represented as -O-, R 1is an ethylene group, the molar mean of p = 4, R 2 = Pentylene group, R 3 It is a monomer represented by a hydrogen atom, and its SP value is 10.87.

[0132] <Manufacturing Example 3> [Manufacturing of Monomer (a-3)] In a reaction vessel equipped with a temperature controller, stirring blades, vacuum device, Liebig condenser, fractionation column, distillate receiving flask, nitrogen inlet and outlet, 260.3 parts by weight (2.0 moles) of 2-hydroxyethyl methacrylate (HEMA), 228.3 parts by weight (2.0 moles) of ε-caprolactone, 3.7 parts by weight (0.03 moles) of hydroquinone monomethyl ether, and 0.27 parts by weight of butyltris(2-ethylhexanoyloxy)tin were added, and the mixture was heated to 115°C while stirring with air flowing through. The reaction was then carried out at 115°C for 8 hours, and the distillate was separated. The mixture was then cooled to 25°C, 1 The esterification reaction product was confirmed by 1H-NMR (yield 53 mol%). Subsequently, 2-hydroxyethyl methacrylate (HEMA), which remained as an impurity at a concentration of 47 mol%, was removed by silica column chromatography. (a-3) is where A in general formula (1) is a methacryloyl group, and -X 1 -, -X 2 - and -X 3 - represents a group represented as -O-, R 1 is an ethylene group, the molar mean of p = 1.9, R 2 = Pentylene group, R 3 It is a monomer represented by a hydrogen atom, and its SP value is 11.36.

[0133] <Manufacturing Example 4> [Manufacturing of Monomer (a-4)] In a reaction vessel equipped with a temperature controller, stirring blades, vacuum device, Liebig condenser, fractionation column, distillate receiving flask, nitrogen inlet and outlet, 232.2 parts by weight (2.0 moles) of 2-hydroxyethyl acrylate (hereinafter abbreviated as HEA), 456.6 parts by weight (4.0 moles) of ε-caprolactone, 3.7 parts by weight (0.03 moles) of hydroquinone monomethyl ether, and 0.27 parts by weight of butyltris(2-ethylhexanoyloxy)tin were added, and the mixture was heated to 115°C while stirring with air flowing through. The reaction was then carried out at 115°C for 8 hours, and the distillate water was separated. The mixture was then cooled to 25°C, 1 The esterification reaction product was confirmed by 1H-NMR (yield 76 mol%). Subsequently, 24 mol% of 2-hydroxyethyl acrylate (HEA) remained as an impurity and was removed by silica column chromatography. (a-4) In general formula (1), A is an acryloyl group, and -X 1 -, -X 2 - and -X 3 - represents a group represented as -O-, R 1 is an ethylene group, the molar mean of p = 2.6, R 2 = Pentylene group, R 3 It is a monomer represented by a hydrogen atom, and its SP value is 11.30.

[0134] <Examples 1-27, Comparative Examples 1-4> In a reaction vessel equipped with a stirring device, a heating / cooling device, a thermometer, and a nitrogen inlet tube, 185 parts by weight of ethyl acetate, 100 parts by weight of a mixture of various monomers listed in Tables 2-3, and the amounts of dodecyl mercaptan and 2,2'-azobis(2-methylbutyronitrile) listed in Tables 2-3 as initiator and chain transfer agent were added. After purging with nitrogen (gas phase oxygen concentration 100 ppm), the mixture was heated to 76°C under a sealed container while stirring, and the polymerization reaction was carried out at the same temperature for 6 hours. Mineral oil [SP value: 8.3 (cal / cm³)] 3 ) 1 / 2 kinematic viscosity at 100℃: 4.2 mm 243 parts by weight of [122 / s, viscosity index: 122] were added, the temperature was raised to 120-130°C, and then the unreacted monomers and ethyl acetate were removed over 2 hours under reduced pressure (0.027-0.040 MPa) at the same temperature to obtain the anti-wear agents of the present invention (A-1) to (A-27) and comparative anti-wear agents (B-1) to (B-4) containing 70% by weight of the copolymer.

[0135] [Table 2]

[0136] [Table 3]

[0137] The various monomers listed in Tables 2-3 are as follows: (a-5): HEMA ε-caprolactone 5 molar adduct (mean molar value of p = 5, SP value 10.75) (a-6): HEA ε-caprolactone 10 molar adduct (mean molar value of p = 10, SP value 10.68) (a-7): HEMA ε-caprolactone 20 molar adduct (mean molar value of p = 20, SP value 11.32) (a-8): Terminal butyl ester of the ε-caprolactone 4-mol adduct of HEMA (mean molar value of p = 4, SP value 9.96) (a-9): Terminal butyl ester of the 7-mol adduct of ε-caprolactone to HEMA (mean molar value of p = 7, SP value 10.40) (b-1): ω-carboxypolycaprolactone (with 2 moles of caprolactone added) monoacrylate (Aronix M-5300, manufactured by Toagosei Co., Ltd.) (R in general formula (2)) 4 is a hydrogen atom, -X 4 - is -O-, R 5 (This is a pentylene group, q=2) (b-2): β-carboxyethyl acrylate (β-CEA, manufactured by Daicel Ornex Co., Ltd.) (R in general formula (2)) 4 is a hydrogen atom, -X 4 - is -O-, R5 (This is an ethylene group, q=1) (c-1): Methacrylic acid ester of Neodol23 (manufactured by Shell Chemicals, a mixture of linear or branched alkyl alcohols with 12 to 13 carbon atoms (weight ratio = linear C12:branched C12:linear C13:branched C13 = 40:10:40:10)) (c-2): n-hexadecyl methacrylate (c-3): n-octadecyl methacrylate (c-4): Decyltetradecyl methacrylate (c-5): 2-docylhexadecyl methacrylate (c-6): 2-tetradecyl octadecyl methacrylate (c-7): Dodecyl acrylate (c-8): n-octadecyl acrylate (d-1): N,N-dimethylaminoethyl methacrylate (e-1): 2-hydroxyethyl acrylate (e-2): 2-hydroxyethyl methacrylate (e-3): 2-hydroxy-2-methylpropyl methacrylate

[0138] <Examples 28-54, Comparative Examples 5-8> The obtained anti-wear agents (A-1) to (A-27), and the comparative anti-wear agents (B-1) to (B-4) were added to Toyota Motor Corporation's genuine e-transaxle fluid TE in an amount of 2% by weight relative to the weight of the base oil (amount added in terms of solid matter), to obtain lubricating oil compositions (V-1) to (V-27) and (W-1) to (W-4).

[0139] <Added kinematic viscosity> The kinematic viscosity at 100°C and 40°C of lubricating oil compositions (V-1) to (V-27) and (W-1) to (W-4) was measured using the method described in JIS-K2283 (2000). The results are shown as the added kinematic viscosity (mm²). 2 The values ​​( / s) are shown in Tables 2 and 3.

[0140] <Viscosity index> The viscosity indices of lubricating oil compositions (V-1) to (V-27) and (W-1) to (W-4) were measured using the method described in JIS-K2283 (2000), and the results are shown in Tables 2 and 3.

[0141] The copper corrosiveness, volume resistivity, and wear evaluation of lubricating oil compositions (V-1) to (V-27) and (W-1) to (W-4) were measured using the following method. The results are shown in Tables 2 and 3.

[0142] <Copper corrosion> A copper plate corrosion test was conducted at 150°C for 12 hours, in accordance with JIS K2513:2000 (Petroleum products - Copper plate corrosion test method). The degree of discoloration of the copper plate after the test was compared to the copper plate corrosion standard, and the discoloration number was recorded. Lubricating oil compositions with a discoloration number of "1" were deemed acceptable.

[0143] <Volume resistivity> The volume resistivity of each lubricating oil composition was measured at room temperature using a non-aqueous conductivity meter (Dispersion Technology, model number: DT700). The higher the volume resistivity, the better the electrical insulation performance, 0.5 × 10 10 A value of Ω·cm or higher indicates good electrical insulation.

[0144] <Wear evaluation> The tests were conducted in accordance with ASTM D 2783, except for the test conditions described below. Specifically, for each lubricating oil composition, a load of 500 N was applied to a high-speed four-ball tester and rotated for 10 seconds to check for seizure. If seizure did not occur, the load was increased by 10 N and the next test was performed, and the load just before seizure occurred was measured as the maximum non-seizure load (N). A higher value indicates that seizure is less likely to occur and that the wear prevention effect is superior. <Measurement conditions> Equipment: Space Creation Co., Ltd. KRL & Four Ball Test Machine Ball:Steel Balls for Four Ball Bearings, Size:1 / 2 Speed:1760rpm Temperature: 25℃ Test duration: 10 seconds Test starting load: 500N Load increase interval: 10N

[0145] As is clear from the results in Tables 2-3, the lubricating oil compositions containing the wear inhibitor of the present invention (Examples 28-54) exhibit high wear prevention, low copper corrosion, high volume resistivity, and excellent insulating properties. On the other hand, the lubricating oil compositions of Comparative Examples 5-8 are found to be significantly inferior to the lubricating oil compositions containing the wear inhibitor of the present invention in at least one of the following properties: wear prevention, copper corrosion, and insulating properties. [Industrial applicability]

[0146] The lubricating oil composition containing the wear inhibitor of the present invention is suitable as a drivetrain lubricant (MTF, differential gear oil, ATF, and belt-CVTF, etc.), hydraulic fluid (machine hydraulic fluid, power steering oil, and shock absorber oil, etc.), engine oil (for gasoline and diesel engines, etc.), traction oil, and motor oil in electric vehicles or hybrid vehicles.

Claims

1. An anti-wear agent comprising a copolymer (A) having monomer (a) represented by the following general formula (1), monomer (b) represented by the following general formula (2), and monomer (c) represented by the following general formula (3) as essential constituent monomers, wherein the weight ratio (a / b) of monomer (a) to monomer (b) in the monomers constituting the copolymer (A) is 0.5 to 80, and the acid value of the copolymer (A) is 1.0 to 38 mgKOH / g. 【Chemistry 1】 [In general formula (1), A is a polymerizable unsaturated group having 2 to 5 carbon atoms; -X １ -, -X ２ - and -X ３ Each of the -s is a group independently represented as -O-; R １ R is an alkylene group having 1 to 4 carbon atoms; ２ R is an alkylene group having 2 to 20 carbon atoms; ３ R is a hydrogen atom or a linear or branched aliphatic hydrocarbon group having 1 to 44 carbon atoms; p is an integer from 1 to 100, and if p is 2 or more, there are multiple R ２ and X ３ These may be the same or different. 【Chemistry 2】 [In general formula (2), R ４ is a hydrogen atom or a methyl group; -X ４ - is a group represented by -O-; R ５ represents an alkylene group having 1 to 10 carbon atoms. q is an integer of 1 to 100, and when q is 2 or more, R ５ may be the same or different. ] 【Transformation 3】 [In general formula (3), R ６ is a hydrogen atom or a methyl group; -X ５ - represents a group represented by -O-; R ７ [It is a linear or branched alkyl group having 5 to 44 carbon atoms.]

2. The anti-wear agent according to claim 1, wherein the total weight ratio of monomer (a) and monomer (b) in the monomers constituting the copolymer (A) is 15 to 50% by weight based on the total weight of the constituent monomers of (A).

3. The anti-wear agent according to claim 1, wherein the weight-average molecular weight of the copolymer (A) is 0.5 million to 500,000.

4. A lubricating oil composition comprising an anti-wear agent and a base oil according to any one of claims 1 to 3.

5. The kinematic viscosity of the base oil at 100°C is 1 to 4 mm². ２ The lubricating oil composition according to claim 4, wherein the value is / s.

6. The lubricating oil composition according to claim 4, further comprising at least one selected from the group consisting of viscosity index improvers, detergents, dispersants, antioxidants, oiliness improvers, extreme pressure agents, defoamers, anti-emulsifiers, corrosion inhibitors, and pour point depressants.

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