Defoaming agent, lubricating oil composition containing defoaming agent, and machine using lubricating oil composition

Abstract

Provided is a defoaming agent which exhibits excellent defoaming properties even in a high-temperature environment. A defoaming agent which is a polymer having, as polymerization components, at least a polymerizable monomer (1) having-Si [OSi (R) 3] n [R '] 3-n (n is an integer in the range of 1-3) and a polymerizable monomer (2) having-Si [OSi (R) 3] n [R'] 3-n (n is an integer in the range of 1-3); r is respectively and independently alkyl with the carbon atom number of 1-3; and R'each independently represents a C1-3 alkyl group) and has one polymerizable unsaturated group, and the polymerizable monomer (2) has two or more polymerizable unsaturated groups.

Description

Technical Field

[0001] This invention relates to an antifoaming agent, a lubricating oil composition containing the antifoaming agent, and machinery using the lubricating oil composition. Background Technology

[0002] In recent years, reducing carbon dioxide emissions has become an important issue for industry. Among them, transportation equipment, including automobiles, accounts for nearly 20% of total carbon dioxide emissions. As one of the countermeasures to reduce carbon dioxide emissions, policies in various countries have proposed converting gasoline vehicles into electric vehicles (EVs).

[0003] One of the most important challenges in EVs is improving fuel efficiency, and research is rapidly advancing in areas such as vehicle miniaturization and drive system efficiency. One challenge in improving drive system efficiency is addressing lubricant foaming. To reduce frictional resistance, efforts are being made to lower the viscosity of lubricants, but this lower viscosity also makes them more prone to foaming.

[0004] If continuous high-load operation or high-speed driving occurs, the following problems may sometimes occur: increased foaming in low-viscosity lubricating oil, which leads to a decrease in lubrication performance and cooling efficiency; wear and sintering due to the rupture of the oil film at friction points; and accelerated deterioration of lubricating oil due to the rise in oil temperature.

[0005] Therefore, lubricating oils with high defoaming properties are needed to suppress foaming for a long period of time from the initial stage of operation. These lubricating oils contain defoamers to prevent foaming. Polysiloxane-based defoamers are known as such defoamers, and various polysiloxane-based defoamers have been proposed (e.g., Patent Document 1).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2017-039924 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] Existing polysiloxane-based defoamers have the problem that their defoaming properties decrease significantly with increasing temperature. For example, in automotive applications that require defoaming at high temperatures, they cannot achieve sufficient defoaming performance.

[0011] The problem to be solved by the present invention is to provide a defoamer that exhibits excellent defoaming properties even under high temperature conditions.

[0012] Another problem to be solved by the present invention is to provide a lubricating oil composition that exhibits excellent lubrication performance even under high temperature conditions.

[0013] Solution for solving the problem

[0014] The inventors have conducted intensive research to solve the aforementioned problem and have discovered that polymers containing polymerizable monomers having at least a specific organosilicon functional group and a polymerizable unsaturated group, as well as polymerizable monomers having two or more polymerizable unsaturated groups, are defoamers that exhibit excellent defoaming properties even at high temperatures, thus completing the present invention.

[0015] That is, the present invention relates to the following defoamers, etc.

[0016] 1. An antifoaming agent comprising a polymer having at least a polymeric monomer (1) and a polymeric monomer (2) as polymerizing components, said polymeric monomer (1) having -Si[OSi(R)3] n [R'] 3-n (n is an integer in the range of 1 to 3; R is an alkyl group with 1 to 3 carbon atoms; R' is an alkyl group with 1 to 3 carbon atoms) and has a polymerizable unsaturated group, the polymerizable monomer (2) has two or more polymerizable unsaturated groups.

[0017] 2. The defoamer as described in 1, wherein the polymerizable monomer (1) is a compound represented by the following general formula (1-1).

[0018]

[0019] (In the general formula (1-1),

[0020] R is an alkyl group having 1 to 3 carbon atoms, each independently.

[0021] R' is an alkyl group having 1 to 3 carbon atoms, each independently.

[0022] L 11 It is a divalent organic group or a single bond.

[0023] n is an integer in the range of 1 to 3.

[0024] P represents a polymeric group represented by general formula (P-1), general formula (P-2), or general formula (P-3).

[0025] In the general formulas (P-1), (P-2), and (P-3),

[0026] R 11 It can be a hydrogen atom or a methyl group.

[0027] R 12 It can be a hydrogen atom or an organic group.

[0028] R13 It can be a hydrogen atom or a methyl group.

[0029] *For L 11 (The connecting key of the bond.)

[0030] 3. The defoamer as described in 1 or 2, wherein the content of the polymeric monomer (1) in the polymeric component is in the range of 10% by mass or more.

[0031] 4. The defoamer as described in any one of 1 to 3, wherein the polymerizable monomer (2) is a compound represented by the following general formula (2-1).

[0032]

[0033] (In the general formula (2-1),

[0034] R 21 It can be a hydrogen atom or a methyl group.

[0035] x is an integer greater than or equal to 2.

[0036] L 21 (It is an organic group with an x ​​valence.)

[0037] 5. The defoamer as described in any one of 1 to 4, wherein the content of the polymeric monomer (2) in the polymeric component is in the range of 1% to 75% by mass.

[0038] 6. The defoamer as described in any one of 1 to 5, wherein the polymeric component comprises a polymerizable monomer (3), the polymerizable monomer (3) having one or more of the group consisting of an alkyl group having 1 to 18 carbon atoms, an aromatic group having 6 to 18 carbon atoms, a group comprising a polyoxyalkylene chain, and a group comprising a polyester chain.

[0039] 7. The defoamer as described in 6, wherein the polymerizable monomer (3) is one or more selected from the group consisting of compounds represented by the following general formula (3-1), the following general formula (3-2), the following general formula (3-3), the following general formula (3-4), and the following general formula (3-5).

[0040]

[0041] (Among the general formulas (3-1), (3-2), (3-3), (3-4), and (3-5),

[0042] R 31 It can be a hydrogen atom or a methyl group.

[0043] R 32Alkyl groups having 1 to 18 carbon atoms

[0044] R 33 It can be a hydrogen atom or a methyl group.

[0045] R 34 It is an alkyl group having 1 to 18 hydrogen atoms or carbon atoms.

[0046] R 35 It can be a hydrogen atom or a methyl group.

[0047] R 36 It is an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms with an ether bond, or a hydrogen atom.

[0048] R 37 It can be a hydrogen atom or a methyl group.

[0049] R 38 It is an alkyl group having 1 to 18 carbon atoms, or an alkyl group having 1 to 18 carbon atoms and containing an ether bond, or a hydrogen atom.

[0050] L 3 It is a divalent organic group or a single bond.

[0051] R 39 It can be a hydrogen atom or a methyl group.

[0052] R 40 Each is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms.

[0053] n is an integer in the range of 1 to 4, m represents the number of repetitions, with the mean of m ranging from 1 to 200, p is an integer in the range of 1 to 10, q represents the number of repetitions, with the mean of q ranging from 1 to 100, and l is an integer in the range of 0 to 5.

[0054] 8. The defoamer as described in 6 or 7, wherein the polymerizable monomer (3) comprises a compound represented by the general formula (3-2).

[0055] 9. The defoamer as described in any one of 6 to 8, wherein the content of the polymeric monomer (3) in the polymeric component is in the range of 0% by mass to 75% by mass.

[0056] 10. The defoamer according to any one of 1 to 9, wherein the weight-average molecular weight is in the range of 2,000 to 200,000.

[0057] 11. A lubricating oil composition comprising a lubricating oil base oil and any one of 1 to 10 defoamers.

[0058] 12. The lubricating oil composition as described in 11, used for lubricating the drive unit of a machine equipped with an internal combustion engine or an electric motor.

[0059] 13. The lubricating oil composition as described in 11, used for lubricating the drive unit of a vehicle equipped with an internal combustion engine or an electric motor.

[0060] 14. A machine that uses the lubricating oil composition described in 11 in a drive unit.

[0061] The effects of the invention

[0062] According to the present invention, a defoamer that exhibits excellent defoaming properties even under high temperature conditions can be provided.

[0063] According to the present invention, a lubricating oil composition that exhibits excellent lubrication performance even under high temperature conditions can be provided. Detailed Implementation

[0064] Hereinafter, one embodiment of the present invention will be described. The present invention is not limited to the following embodiment, and may be implemented by appropriate modifications without impairing the effects of the present invention.

[0065] It should be noted that in this application specification, the term "(meth)acrylate" refers to one or both of acrylate and methacrylate.

[0066] [Defoamer]

[0067] The defoamer of the present invention contains a polymer having at least a polymeric monomer (1) and a polymeric monomer (2) as polymerizing components, wherein the polymeric monomer (1) has -Si[OSi(R)3]. n [R'] 3-n (n is an integer from 1 to 3. R is an alkyl group with 1 to 3 carbon atoms. R' is an alkyl group with 1 to 3 carbon atoms) and has a polymerizable unsaturated group, the polymerizable monomer (2) has two or more polymerizable unsaturated groups.

[0068] Here, "polymer components" refers to the components that constitute the polymer, excluding solvents, polymerization initiators, etc., that do not constitute the polymer.

[0069] In this invention, the term "polymerizable monomer" refers to a compound having polymerizable unsaturated groups. Examples of polymerizable unsaturated groups in polymerizable monomers (1) and (2) include: (meth)acryloyl, (meth)acryloyloxy, (meth)acryloylamide, vinyl ether, allyl, styrene, (meth)acryloylamino, maleimide, etc.

[0070] Sometimes, polymers that are used as defoamers of the present invention, which are polymers of at least polymerizable monomers (1) and polymerizable monomers (2), are referred to as "polymers of the present invention".

[0071] The components constituting the polymer of the present invention will be described below.

[0072] The polymerizable monomer (1) possesses -Si[OSi(R)3] n [R'] 3-n The functional group shown is preferably the functional group shown as -Si[OSi(R)3]3, and more preferably -Si[OSi(CH3)3]3.

[0073] The polymerizable monomer (1) is preferably a compound represented by the following general formula (1-1).

[0074]

[0075] (In the general formula (1-1),

[0076] R is an alkyl group having 1 to 3 carbon atoms, each independently.

[0077] R' is an alkyl group having 1 to 3 carbon atoms, each independently.

[0078] L 11 It is a divalent organic group or a single bond.

[0079] n is an integer in the range of 1 to 3.

[0080] P represents a polymeric group represented by general formula (P-1), general formula (P-2), or general formula (P-3).

[0081] In the general formulas (P-1), (P-2), and (P-3),

[0082] R 11 It can be a hydrogen atom or a methyl group.

[0083] R 12 It can be a hydrogen atom or an organic group.

[0084] R 13 It can be a hydrogen atom or a methyl group.

[0085] *For L 11 (The connecting key of the bond.)

[0086] The so-called L 11 The "single bond" refers to the case where O and Si are directly bonded.

[0087] L 11The divalent organic group is preferably an alkylene group with 1 to 50 carbon atoms or an alkene group with 1 to 50 carbon atoms.

[0088] As L 11 Alkyl groups with 1 to 50 carbon atoms can be listed as follows: methylene, ethylene, n-propylene, n-butylene, n-pentylene, n-hexylene, n-heptylene, n-octylene, n-nonylene, n-decylene, n-dodecylene, isopropylene, 2-methylpropylene, 2-methylhexylene, tetramethylethylene, etc.

[0089] L 11 The alkylene group having 1 to 50 carbon atoms is preferably an alkylene group having 1 to 15 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and even more preferably methylene, ethylene, n-propylene or isopropylene.

[0090] L 11 One or more of the -CH2- groups in the alkylene group having 1 to 50 carbon atoms are replaced with -O- groups.

[0091] L 11 The alkene oxide with 1 to 50 carbon atoms is preferably an alkene oxide with 1 to 15 carbon atoms, more preferably an alkene oxide with 1 to 8 carbon atoms, and even more preferably a methylene oxide, ethoxide oxide, propoxy oxide, oxytrimethylene oxide, butoxyoxide oxide, oxytetramethylene oxide, pentylene oxide, heptoxyoxide oxide, or octyl oxide oxide.

[0092] In L 11 When the divalent organic group is an alkylene group with 1 to 50 carbon atoms or an alkene group with 1 to 50 carbon atoms, part of the -CH2- of these divalent organic groups may be replaced by a carbonyl group (-C(=O)-), a phenylene group, an amide bond or a carbamate bond (-NHC(=O)-).

[0093] In L 11 When the divalent organic group is an alkylene group with 1 to 50 carbon atoms or an alkene group with 1 to 50 carbon atoms, a hydroxyl group or other substituent may be further substituted on the carbon atoms of these groups.

[0094] As R 12 Organic groups, for example, alkyl groups having 1 to 18 carbon atoms.

[0095] As R 12 Alkyl groups with 1 to 18 carbon atoms can be listed as follows: methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-dodecyl, isopropyl, 2-methylpropyl, 2-methylhexyl, tetramethylethyl, etc.

[0096] n is preferably 2 or 3, and more preferably 3.

[0097] The compound represented by general formula (1-1) is preferably the compound represented by general formula (1-2) (n=3) or the compound represented by general formula (1-3) (n=2), and more preferably the compound represented by general formula (1-2).

[0098]

[0099] (In the general formulas (1-2) and (1-3),

[0100] P, R', R 11 and L 11 P, R', R of the general formula (1-1) 11 and L 11 same)

[0101] The polymerizable monomer (1) that serves as a polymerizing component can be a single monomer or two or more polymerizable monomers (1) with different structures.

[0102] Polymerizable monomers (1) can be manufactured by known methods or commercially available products can be used.

[0103] Commercially available polymerizable monomers (1) include, for example, 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane.

[0104] As a polymerizable monomer (1), in addition to the 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane, the following compounds may also be used, for example.

[0105]

[0106] In the polymer of the present invention, the lower limit of the content of the polymerizable monomer (1) relative to the total amount of polymeric components of the polymer is, for example, 10% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, or 35% by mass or more.

[0107] There is no particular limit to the upper limit of the proportion of the polymerizable monomer (1), which is, for example, 99% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less or 60% by mass or less relative to the total amount of polymeric components.

[0108] As a combination of the upper and lower limits of the content of the polymerizable monomer (1), for example, a range of 10% to 99% by mass of the total polymeric component of the polymer can be listed, and a range of 25% to 80% by mass of the total polymeric component of the polymer is preferred.

[0109] The proportion of polymerizable monomer (1) can be adjusted according to the raw material input ratio of polymerizable monomer (1) when manufacturing the polymer of the present invention.

[0110] Polymerizable monomer (2) is a polymerizable monomer having two or more polymerizable unsaturated groups. It may have two or more polymerizable unsaturated groups of one kind or two kinds of polymerizable unsaturated groups.

[0111] The polymerizable monomer (2) is preferably a polymerizable monomer having two or more (meth)acryloyl groups or a polymerizable monomer having two or more (meth)acryloyloxy groups.

[0112] The polymerizable monomer (2) is preferably a compound represented by the following general formula (2-1).

[0113]

[0114] (In the general formula (2-1),

[0115] R 21 It can be a hydrogen atom or a methyl group.

[0116] n² is an integer greater than or equal to 2.

[0117] L 21 (It is an n2-valent organic group.)

[0118] n2 can be any integer greater than or equal to 2, such as an integer in the range of 2 to 12, preferably an integer in the range of 2 to 8, more preferably an integer in the range of 2 to 6, and even more preferably an integer in the range of 2 to 4.

[0119] L 21 The n2 valence organic group is an organic group with a valence corresponding to the value of n2. For example, when n2 is 2, it is a divalent organic group, and when n2 is 6, it is a hexavalent organic group.

[0120] L 21 Preferably, it is an alkylene group having 1 to 50 carbon atoms or an alkene group having 1 to 50 carbon atoms, and is an organic group formed by replacing the hydrogen atoms bonded to carbon atoms of the alkylene group and the alkene group with linkage bonds in such a way that the valence corresponding to the value of n2 is obtained.

[0121] Therefore, in L 21 In the case of a divalent organic group, L 21 Preferably, it is an alkylene group or an alkene group with 1 to 50 carbon atoms.

[0122] As L 21Alkyl groups with 1 to 50 carbon atoms can be listed as follows: methylene, ethylene, n-propylene, n-butylene, n-pentylene, n-hexylene, n-heptylene, n-octylene, n-nonylene, n-decylene, n-dodecylene, isopropylene, 2-methylpropylene, 2-methylhexylene, tetramethylethylene, etc.

[0123] L 21 The alkylene group having 1 to 50 carbon atoms is preferably an alkylene group having 1 to 15 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and even more preferably methylene, ethylene, n-propylene or isopropylene.

[0124] L 21 One or more of the -CH2- groups in the alkylene group having 1 to 50 carbon atoms are replaced with -O- groups.

[0125] L 21 The alkene oxide with 1 to 50 carbon atoms is preferably an alkene oxide with 1 to 15 carbon atoms, more preferably an alkene oxide with 1 to 8 carbon atoms, and even more preferably a methylene oxide, ethoxide oxide, propoxy oxide, oxytrimethylene oxide, butoxyoxide oxide, oxytetramethylene oxide, pentylene oxide, heptoxyoxide oxide, or octyl oxide oxide.

[0126] In L 21 When the divalent organic group is an alkylene group with 1 to 50 carbon atoms or an alkene group with 1 to 50 carbon atoms, a portion of the -CH2- of these divalent organic groups may be replaced by a carbonyl group (-C(=O)-), a phenylene group, a thioether bond (-S-), an amide bond, or a carbamate bond.

[0127] In L 21 When the divalent organic group is an alkylene group with 1 to 50 carbon atoms or an alkene group with 1 to 50 carbon atoms, a hydroxyl group or other substituent may be further substituted on the carbon atoms of these groups.

[0128] Specific examples of polymerizable monomers (2) include: ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 2-hydroxy-3-methacryloylpropyl acrylate, 2-hydroxy-1,3-dimethacryloyloxypropane, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, tricyclodecanediethanol di(meth)acrylate. Esters, ethoxylated bisphenol A di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, tri-(2-acryloyloxyethyl)isocyanurate, bis-(2-acryloyloxyethyl)isocyanurate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, di(trimethylolpropane) tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, polypentaerythritol poly(meth)acrylate, etc.

[0129] The polymerizable monomer (2) that serves as a polymerizing component can be a single monomer or two or more polymerizable monomers (2) with different structures.

[0130] Polymerizable monomers (2) can be manufactured by known methods or commercially available products can be used.

[0131] In the polymer of the present invention, the proportion of the polymerizable monomer (2) relative to 100 parts by mass of the polymerizable monomer (1) is, for example, in the range of 0.1 parts by mass to 900 parts by mass, preferably in the range of 1 parts by mass to 500 parts by mass relative to 100 parts by mass of the polymerizable monomer (1), more preferably in the range of 3 parts by mass to 300 parts by mass relative to 100 parts by mass of the polymerizable monomer (1). Even more preferably, it is in the range of 5 parts by mass to 200 parts by mass relative to 100 parts by mass of the polymerizable monomer (1).

[0132] The proportion of polymerizable monomer (2) can be adjusted according to the raw material input ratio of polymerizable monomer (2) when manufacturing the polymer of the present invention.

[0133] In the polymer of the present invention, the proportion of the polymerizable monomer (2) relative to the total amount of polymeric components is, for example, in the range of 0.1% to 90% by mass, preferably in the range of 1% to 75% by mass, more preferably in the range of 3% to 60% by mass, and even more preferably in the range of 5% to 50% by mass.

[0134] In addition to polymerizable monomers (1) and (2), polymerizable monomers (3) are preferably used as polymerizable components in the polymer of the present invention. The polymerizable monomer (3) has one or more of the following groups: alkyl groups having 1 to 18 carbon atoms, aromatic groups having 6 to 18 carbon atoms, groups containing polyoxyalkylene chains, and groups containing polyester chains.

[0135] By also including a polymerizable monomer (3) as a polymerization component, for example, when the defoamer of the present invention is added to a lubricating oil composition, the high compatibility of the defoamer with respect to the lubricating oil base oil can be ensured.

[0136] The alkyl group with 1 to 18 carbon atoms in the polymerizable monomer (3) can be any of the following: straight-chain alkyl, branched alkyl and cyclic alkyl. For specific examples, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-hexyl, cyclohexyl, n-octyl, hexadecyl, etc.

[0137] The alkyl group having 1 to 18 carbon atoms in the polymerizable monomer (3) is preferably an alkyl group having 1 to 6 carbon atoms.

[0138] Aromatic groups with 6 to 18 carbon atoms that are polymerizable monomers (3) can be listed as: phenyl, naphthyl, anthracene-1-yl, phenanthrene-1-yl, etc.

[0139] The group containing the (poly)oxoalkylene chain in the so-called polymeric monomer (3) is a monovalent group containing the repeating part of the oxoalkylene or a divalent linking group containing the repeating part of the oxoalkylene.

[0140] The polymerizable monomer (3) contains groups that include polyester chains, which are either monovalent groups containing repeating portions of ester bonds or divalent linking groups containing repeating portions of ester bonds.

[0141] The alkyl group with 1 to 18 carbon atoms in the polymerizable monomer (3) may further have substituents, such as hydroxyl, aryl, etc.

[0142] The aromatic groups with 6 to 18 carbon atoms in the polymerizable monomer (3) may further have substituents, such as hydroxyl, alkyl and the like.

[0143] Examples of polymerizable monomers (3) that are alkyl groups having 1 to 18 carbon atoms and whose polymerizable unsaturated group is (meth)acryloyl group include: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, n-heptyl methacrylate, n-octyl methacrylate, and 2-ethylhexyl methacrylate. Alkyl esters of (meth)acrylic acid with 1 to 18 carbon atoms, such as decyl methacrylate, dodecyl methacrylate, stearyl methacrylate, and isostearyl methacrylate; and cross-linked cyclic alkyl esters of (meth)acrylic acid with 1 to 18 carbon atoms, such as dicyclopentyloxyethyl methacrylate, isobornyloxyethyl methacrylate, isobornyl methacrylate, adamantyl methacrylate, dimethyl adamantyl methacrylate, dicyclopentyl methacrylate, and dicyclopentenyl methacrylate.

[0144] It should be noted that in this application, the term "(meth)acrylate" refers to both methacrylate and acrylate.

[0145] Polymerizable monomers (3) having a phenylalkyl group having 7 to 18 carbon atoms or a phenoxyalkyl group having 7 to 18 carbon atoms and a polymerizable unsaturated group of (meth)acryloyl, for example: benzyl (meth)acrylate, phenoxymethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, etc.

[0146] As polymeric monomers having 1 to 18 carbon atoms and a polymerizable unsaturated group of vinyl ether (3), examples include: methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, n-dodecyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether and other alkyl vinyl ethers; cycloalkyl vinyl ethers, etc.

[0147] Examples of polymerizable monomers (3) that have aromatic groups with 6 to 18 carbon atoms include styrene, α-methylstyrene, p-methylstyrene, p-methoxystyrene, etc.

[0148] As polymeric monomers (3) having alkyl groups with 1 to 18 carbon atoms and polymerizable unsaturated groups of (meth)acryloylamino, examples include: N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, diacetoneacrylamide, acryloylmorpholine, etc.

[0149] As polymeric monomers having 1 to 18 carbon atoms and whose polymeric unsaturated group is maleimide (3), examples include: methyl maleimide, ethyl maleimide, propyl maleimide, butyl maleimide, hexyl maleimide, octyl maleimide, dodecyl maleimide, stearyl maleimide, cyclohexyl maleimide, etc.

[0150] Examples of polymerizable monomers (3) that have a group containing a polyoxyalkylene chain and whose polymerizable unsaturated group is a (meth)acryloyl group include: polypropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, polytrimethylene glycol mono(meth)acrylate, polytetramethylene glycol mono(meth)acrylate, poly(ethylene glycol-propylene glycol) mono(meth)acrylate, polyethylene glycol-polypropylene glycol mono(meth)acrylate, poly(ethylene glycol-tetramethylene glycol) mono(meth)acrylate, and poly(ethylene glycol-tetramethylene glycol) mono(meth)acrylate. Poly(propylene glycol-tetramethylene glycol) mono(meth)acrylate, poly(propylene glycol-tetramethylene glycol) mono(meth)acrylate, poly(propylene glycol-1,2-butanediol) mono(meth)acrylate, poly(propylene glycol-poly(1,2-butanediol) mono(meth)acrylate, poly(ethylene glycol-1,2-butanediol) mono(meth)acrylate, poly(ethylene glycol-poly(1,2-butanediol) mono(meth)acrylate, poly(tetraethylene glycol-1,2-butanediol) mono(meth)acrylate, poly(tetraethylene glycol-1,2-butanediol) mono(meth)acrylate 1,2-Butanediol mono(meth)acrylate, poly(ethylene glycol-trimethylenediol) mono(meth)acrylate, poly(ethylene glycol-trimethylenediol) mono(meth)acrylate, poly(ethylene glycol-trimethylenediol) mono(meth)acrylate, poly(propylene glycol-trimethylenediol) mono(meth)acrylate, poly(propylene glycol-trimethylenediol) mono(meth)acrylate, poly(trimethylenediol-tetramethylenediol) mono(meth)acrylate, poly(trimethylenediol-poly(trimethylenediol) ... Methyl glycol mono(meth)acrylate, poly(1,2-butanediol-trimethylenediol) mono(meth)acrylate, poly(1,2-butanediol-polytrimethylenediol) mono(meth)acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, poly(1,2-butanediol-tetramethylenediol) mono(meth)acrylate, poly(1,2-butanediol-tetramethylenediol) mono(meth)acrylate, etc.

[0151] It should be noted that "poly(ethylene glycol-propylene glycol)" refers to a random copolymer of ethylene glycol and propylene glycol, and "polyethylene glycol-polypropylene glycol" refers to a block copolymer of ethylene glycol and propylene glycol.

[0152] The polymerizable monomer (3) is preferably one or more selected from the group consisting of the compound represented by the following general formula (3-1), the compound represented by the following general formula (3-2), the compound represented by the following general formula (3-3), and the compound represented by the following general formula (3-4).

[0153]

[0154] (Among the general formulas (3-1), (3-2), (3-3), (3-4), and (3-5),

[0155] R 31 It can be a hydrogen atom or a methyl group.

[0156] R 32 Alkyl groups having 1 to 18 carbon atoms

[0157] R 33 It can be a hydrogen atom or a methyl group.

[0158] R 34 It is an alkyl group having 1 to 18 hydrogen atoms or carbon atoms.

[0159] R 35 It can be a hydrogen atom or a methyl group.

[0160] R 36 It is an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms with an ether bond, or a hydrogen atom.

[0161] R 37 It can be a hydrogen atom or a methyl group.

[0162] R 38 It is an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms with an ether bond, or a hydrogen atom.

[0163] L 3 It is a divalent organic group or a single bond.

[0164] R 39 It can be a hydrogen atom or a methyl group.

[0165] R 40 Each is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms.

[0166] n is an integer in the range of 1 to 4, m represents the number of repetitions, with the mean of m ranging from 1 to 200, p is an integer in the range of 1 to 10, q represents the number of repetitions, with the mean of q ranging from 1 to 100, and l is an integer in the range of 0 to 5.

[0167] In the above equation (3-2), the m n inside the parentheses can be the same or different from each other.

[0168] In the above equation (3-3), the q p's within the parentheses can be the same or different from each other.

[0169] In equation (3-4), the q p's within the parentheses can be the same or different from each other.

[0170] R 32 R 34 R 36 and R 38 Alkyl groups having 1 to 18 carbon atoms may further have substituents, such as hydroxyl, aryl, etc.

[0171] R 36 and R 38 Alkyl groups with 1 to 18 carbon atoms and ether bonds may further have substituents, such as hydroxyl, aryl, etc.

[0172] R 30 Alkyl groups having 1 to 6 carbon atoms may further have substituents, such as hydroxyl, aryl, etc.

[0173] R 40 The alkoxy group with 1 to 6 carbon atoms may further have substituents, such as hydroxyl, aryl, etc.

[0174] L in equations (3-3) and (3-4) 3 Divalent organic groups can be listed as those related to L 11 The same group as the divalent organic group.

[0175] In the general formula (3-2), m represents the number of repetitions, for example, m can be any integer greater than or equal to 1. The mean of m is, for example, in the range of 1 to 200, preferably in the range of 1 to 100, and more preferably in the range of 1 to 50.

[0176] The number mean of m can be confirmed by measuring the number mean molecular weight of the polymeric monomer (3) using the method described in the examples.

[0177] In the general formulas (3-3) and (3-4), q represents the number of repetitions, for example, q only needs to be an integer greater than or equal to 1. The mean of q is, for example, in the range of 1 to 100, preferably in the range of 1 to 80, and more preferably in the range of 1 to 50.

[0178] The polymerizable monomer (3) preferably comprises one or more compounds selected from the group consisting of the compound represented by formula (3-2), the compound represented by formula (3-3), and the compound represented by formula (3-4).

[0179] When the polymerizable monomer (3) comprises one or more compounds selected from the group consisting of the compound shown in formula (3-2), the compound shown in formula (3-3), and the compound shown in formula (3-4), it is preferable that the total amount of the compound shown in formula (3-2), the compound shown in formula (3-3), and the compound shown in formula (3-4) is 50% by mass or more relative to the total amount of the polymerizable monomer (3).

[0180] The polymerizable monomer (3) that is a polymerizable component can be a single monomer or two or more polymerizable monomers (3) with different structures.

[0181] Polymerizable monomers (3) can be manufactured by known methods.

[0182] In addition, commercially available products can be used for polymerizable monomers (3). For example, commercially available products that are polymerizable monomers (3) having a group containing a polyoxyalkylene chain and a polymerizable unsaturated group of (meth)acryloyl group include “NK Ester M-20G”, “NK Ester M-40G”, “NK Ester M-90G”, “NK Ester M-230G”, “NK Ester AM-90G”, “NK Ester AMP-10G”, “NK Ester AMP-20G”, and “NK Ester AMP-60G” manufactured by Shin-Nakamura Chemical Industry Co., Ltd., and “Blemmer PE-90”, “Blemmer PE-200”, “Blemmer PE-350”, “Blemmer PME-100”, “Blemmer PME-200”, “Blemmer PME-400”, “Blemmer PME-4000”, “Blemmer PP-1000”, “Blemmer PP-500”, “Blemmer PP-800”, “Blemmer PME-200”, “Blemmer PME-4000”, “Blemmer PP-4000”, “Blemmer PP-1000”, “Blemmer PP-500”, “Blemmer PP-800”, “Blemmer PME-200”, “Blemmer PME-200”, “Blemmer PME-40 ... Products include “70PEP-350B”, “Blemmer 55PET-800”, “Blemmer 50POEP-800B”, “Blemmer 10PPB-500B”, “Blemmer NKH-5050”, “Blemmer AP-400”, “Blemmer AE-350”, the Placcel F series manufactured by Daicel Co., Ltd., and the Viscoat series manufactured by Osaka Organic Chemical Industry Co., Ltd.

[0183] When a polymerizable monomer (3) is included as a polymerizing component, the proportion of the polymerizable monomer (3) is, for example, 0 to 200 parts by mass relative to 100 parts by mass of the polymerizable monomer (1), preferably 20 to 200 parts by mass relative to 100 parts by mass of the polymerizable monomer (1), more preferably 40 to 150 parts by mass relative to 100 parts by mass of the polymerizable monomer (1), and even more preferably 70 to 120 parts by mass relative to 100 parts by mass of the polymerizable monomer (1).

[0184] The proportion of polymerizable monomer (3) can be adjusted according to the raw material input ratio of polymerizable monomer (3) when manufacturing the polymer of the present invention.

[0185] In the polymer of the present invention, the proportion of the polymerizable monomer (3) relative to the total amount of polymeric components is, for example, in the range of 0% to 90% by mass, preferably in the range of 1% to 80% by mass, more preferably in the range of 3% to 75% by mass, and even more preferably in the range of 5% to 70% by mass.

[0186] The polymer of the present invention can be any polymer that uses polymeric monomer (1), polymeric monomer (2) and any polymeric monomer (3) as polymerizing components. Without impairing the effect of the present invention, it may also include other polymeric monomers besides polymeric monomer (1), polymeric monomer (2) and any polymeric monomer (3) as polymerizing components.

[0187] The polymer of the present invention is preferably a polymer whose polymeric components are substantially composed of polymeric monomers (1), polymeric monomers (2) and optional polymeric monomers (3), and more preferably a copolymer whose polymeric components are composed only of polymeric monomers (1), polymeric monomers (2) and optional polymeric monomers (3).

[0188] Here, "substantially constitutes" means that the total content of the polymeric monomer (1), polymeric monomer (2) and optional polymeric monomer (3) in the polymeric component of the polymer of the present invention is 80% or more by mass, 90% or more by mass, 95% or more by mass, or 99% or more by mass.

[0189] The polymerization form of the polymers of the present invention is not particularly limited.

[0190] The polymer of the present invention may be a random polymer of polymeric monomer (1), polymeric monomer (2) and optionally polymeric monomer (3). Alternatively, the polymer of the present invention may also be a block polymer having polymer blocks of any one or more of polymeric monomer (1), polymeric monomer (2) and optionally polymeric monomer (3).

[0191] The polymer of the present invention preferably does not contain fluorine atoms.

[0192] The number-average molecular weight (Mn) of the polymer of the present invention is preferably in the range of 1,000 to 50,000, more preferably in the range of 1,000 to 30,000, and even more preferably in the range of 1,500 to 10,000.

[0193] The weight-average molecular weight (Mw) of the polymer of the present invention is preferably in the range of 1,000 to 300,000, more preferably in the range of 1,500 to 250,000, even more preferably in the range of 2,000 to 200,000, and particularly preferably in the range of 3,000 to 150,000.

[0194] In this invention, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are values ​​obtained by measuring polystyrene using gel permeation chromatography (GPC).

[0195] The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the polymers of the present invention were determined by the methods described in the examples.

[0196] The defoamer of the present invention may contain only the polymer of the present invention, or it may contain defoamers other than the polymer of the present invention. Alternatively, the defoamer of the present invention may also be the polymer of the present invention.

[0197] [Polymer Manufacturing Methods]

[0198] The manufacturing method of the polymer of the present invention is not particularly limited and can be carried out by known methods.

[0199] The polymers of the present invention can be manufactured using polymerization mechanisms such as free radical polymerization, cationic polymerization, and anionic polymerization, via solution polymerization, bulk polymerization, emulsion polymerization, etc. For example, in the case of free radical polymerization, the polymers of the present invention can be manufactured by adding a mixture of polymerizable monomers to an organic solvent and adding a common free radical polymerization initiator.

[0200] Various polymerization initiators can be used as the polymerization initiator, such as: peroxides such as tert-butyl peroxide-2-ethylhexanoate, benzoyl peroxide, and diacyl peroxide; azo compounds such as azobisisobutyronitrile, dimethyl azobisisobutyrate, and phenylazotriphenylmethane; and metal chelating compounds such as Mn(acac)3.

[0201] As needed, chain transfer agents such as lauryl thiol, 2-mercaptoethanol, ethyl thioglycolic acid, and octyl thioglycolic acid, as well as thiol compounds with coupling groups such as γ-mercaptopropyltrimethoxysilane, can also be used as chain transfer agents and other additives.

[0202] Examples of organic solvents include: alcohols such as ethanol, isopropanol, n-butanol, isobutanol, and tert-butanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and methyl amyl ketone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and butyl lactate; monocarboxylic acid esters such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, propyl 2-hydroxypropionate, butyl 2-hydroxypropionate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, and butyl 2-methoxypropionate; and dimethyl... Polar solvents such as formamide, dimethyl sulfoxide, and N-methylpyrrolidone; ethers such as methyl cellosolve, cellosolve, butyl cellosolve, butyl carbitol, and ethyl cellosolve acetate; propylene glycols and their esters such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monobutyl ether acetate; halogen solvents such as 1,1,1-trichloroethane and chloroform; ethers such as tetrahydrofuran and dioxane; aromatics such as benzene, toluene, and xylene; and further, fluorinated inert liquids such as perfluorooctane and perfluorotri-n-butylamine.

[0203] These solvents can be used alone or in combination of two or more.

[0204] The polymers of the present invention can also be manufactured by living polymerization such as living radical polymerization and living anionic polymerization.

[0205] In living radical polymerization, a growth reaction can be carried out by reversibly generating a dormant species protected by atoms or atomic groups at the active polymerization end, which then reacts with the monomer. Even if the first monomer is consumed, the growth end does not lose its activity and reacts with successively added second monomers to obtain a block polymer. Examples of such living radical polymerization include: atom transfer radical polymerization (ATRP), reversible addition-cracking radical polymerization (RAFT), nitroxide radical controlled polymerization (NMP), and radical polymerization using organotellurium (TERP). There are no particular restrictions on which method is used, but ATRP is preferred in terms of ease of control. ATRP uses organohalides or sulfonyl halides as polymerization initiators and metal complexes containing transition metal compounds and ligands as catalysts for polymerization.

[0206] Specific examples of polymerization initiators that can be used in ATRP include: 1-phenylethyl chloride, 1-phenylethyl bromide, chloroform, carbon tetrachloride, 2-chloropropionitrile, α,α'-dichloroxylene, α,α'-dibromoxylene, hexa(α-bromomethyl)benzene, alkyl esters of 2-halogenated carboxylic acids (e.g., 2-chloropropionic acid, 2-bromopropionic acid, 2-chloroisobutyric acid, 2-bromoisobutyric acid, etc.) with 1 to 6 carbon atoms, etc.

[0207] More specific examples of alkyl esters of 2-halogenated carboxylic acids having 1 to 6 carbon atoms include, for example, methyl 2-chloropropionate, ethyl 2-chloropropionate, methyl 2-bromopropionate, ethyl 2-bromoisobutyrate, etc.

[0208] The transition metal compound that can be used in ATRP is M n+ X n The compound represented.

[0209] As M n+ X n The transition metal M represented by the transition metal compound n+ It can be obtained from Cu + Cu 2+ Fe 2+ Fe 3+ Ru 2 + Ru 3+ Cr 2+ Cr 3+ Mo 0 Mo + Mo 2+ Mo 3+ W 2+ W 3+ ,Rh 3+ ,Rh 4+ Co + Co 2+ Re 2+ Re 3+ Ni 0 Ni + Mn 3+ Mn 4 + V 2+ V 3+ Zn + Zn 2+ Au + Au 2+ Ag + and Ag 2+ Choose from the groups formed.

[0210] M n+ X n The X in the transition metal compound can be derived from halogen atoms, alkoxy groups with 1 to 6 carbon atoms, or (SO4). 1 / 2 (PO4) 1 / 3 (HPO4) 1 / 2 (H2PO4), trifluoromethanesulfonate, hexafluorophosphate, methanesulfonate, arylsulfonate (preferably benzenesulfonate or toluenesulfonate), SeR11 CN and R 12 Choose from the group composed of COOs. Here, R 11 R represents an aryl, linear, or branched alkyl group with 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms). 12 The alkyl group (preferably methyl) is a straight-chain or branched chain with 1 to 6 carbon atoms, which may be substituted with a halogen 1 to 5 times (preferably substituted with fluorine or chlorine 1 to 3 times).

[0211] M n+ X n The 'n' in the transition metal compound represents the formal charge on the metal, and is an integer from 0 to 7.

[0212] Examples of ligand compounds capable of coordinating with the transition metal of the aforementioned transition metal compound include: compounds having ligands containing one or more nitrogen, oxygen, phosphorus, or sulfur atoms that can coordinate with the transition metal via σ bonds; compounds having ligands containing two or more carbon atoms that can coordinate with the transition metal via π bonds; and compounds having ligands that can coordinate with the transition metal via μ or η bonds.

[0213] There are no particular limitations on the transition metal complexes mentioned above. Preferred examples include transition metal complexes from groups 7, 8, 9, 10, and 11. More preferably, complexes of copper with a valence of 0, copper with a valence of 1, ruthenium with a valence of 2, iron with a valence of 2, or nickel with a valence of 2 are also mentioned.

[0214] Specific examples of catalysts that can be used in ATRP, when the central metal is copper, include complexes with ligands such as 2,2'-bipyridine and its derivatives, 1,10-phenanthroline and its derivatives, tetramethylethylenediamine, pentamethyldiethylenetriamine, and hexamethyltris(2-aminoethyl)amine. Additionally, examples of divalent ruthenium complexes include: ruthenium trichlorotris(triphenylphosphine)dichlorotris(tributylphosphine)dichlororuthenium, ruthenium trichloro(cyclooctadiene)dichlororuthenium, ruthenium dichlorobenzene, ruthenium dichloro(norbornene)dichlorodibis(2,2'-bipyridine)dichlororuthenium, ruthenium trichlorotris(1,10-phenanthroline)dichlororuthenium, and ruthenium trichlorohydrocarbonyl(triphenylphosphine)dichloro ...

[0215] In living radical polymerization, solvents are preferred.

[0216] Solvents used in living radical polymerization include, for example: ester solvents such as ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate; ether solvents such as diisopropyl ether, dimethoxyethane, and diethylene glycol dimethyl ether; halogen solvents such as dichloromethane and dichloroethane; aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohol solvents such as methanol, ethanol, and isopropanol; and aprotic polar solvents such as dimethylformamide and dimethyl sulfoxide.

[0217] The solvent may be used alone or in combination with two or more solvents.

[0218] The preferred polymerization temperature for the active free radical polymerization is in the range of room temperature to 120°C.

[0219] When the polymers of the present invention are manufactured by living radical polymerization, metals originating from the transition metal compounds used in the polymerization may sometimes remain in the obtained polymer. The metals remaining in the obtained polymer can be removed using activated alumina or the like after polymerization.

[0220] [Lubricating oil composition]

[0221] The defoamer of the present invention can preferably be used as a defoamer in a lubricating oil composition, wherein the lubricating oil composition of the present invention contains the defoamer of the present invention.

[0222] The defoamer of the present invention is a polymer with a cross-linked structure, which is formed by using a polymeric monomer (2) having two or more polymerizable unsaturated groups as a polymerization component. Even at high temperatures, the molecular diffusion of the defoamer can be suppressed, thus maintaining its solubility in lubricating oil base oil at a low level. Therefore, the defoamer of the present invention can exhibit high defoaming performance even at high temperatures.

[0223] Furthermore, in machinery equipped with an internal combustion engine or an electric motor, where a high shear force is applied in the drive section of the machinery, the defoamer of the present invention suppresses the reduction of molecular weight through its cross-linking structure, thereby suppressing the decrease in defoaming performance.

[0224] As described above, the defoamer of the present invention has high defoaming performance and can be used without limitation in lubricant compositions for drive systems such as shock absorbers, transmissions, and power steering in automobiles.

[0225] The content ratio of the defoamer of the present invention in the lubricating oil composition of the present invention is not particularly limited, for example, it is in the range of 1 ppm to 1,000 ppm by mass of the total amount of the lubricating oil composition, preferably in the range of 5 ppm to 700 ppm by mass, and even more preferably in the range of 10 ppm to 400 ppm by mass.

[0226] The lubricating oil base oil of the lubricating oil composition of the present invention can be any well-known type, such as mineral oil, synthetic oil, or a mixture of mineral oil and synthetic oil.

[0227] As a mineral oil, there are examples such as: mineral oils refined by vacuum distillation of the atmospheric residue obtained from atmospheric distillation of crude oil to obtain lubricating oil fractions, and then refining the obtained lubricating oil fractions by performing one or more of the following processes: solvent deasphalting, solvent extraction, hydrogenation decomposition, solvent dewaxing, catalytic dewaxing, hydrogenation refining, etc. Examples include paraffinic mineral oils and cycloalkane mineral oils.

[0228] Alternatively, examples include mineral oils produced by isomerizing mineral oil-based waxes and GTL waxes manufactured using the Fischer-Tropsch process.

[0229] Synthetic oils include: polyolefins such as polybutene, α-olefin homopolymers or copolymers (e.g., ethylene-α-olefin copolymers); various esters such as polyol esters, diesters, and phosphate esters; various ethers such as polyphenyl ethers; and polydiols, alkylbenzenes, and alkylnaphthalenes.

[0230] Lubricating oil base oil can be used alone or in combination of two or more.

[0231] The preferred dynamic viscosity of the lubricating oil base oil at 100°C is 1 mm. 2 / s~20mm 2 The range of / s is more preferably 2mm. 2 / s~15mm 2 The range of / s is preferably 2mm. 2 / s~10mm 2 The range of / s.

[0232] By keeping the dynamic viscosity of the lubricating oil base oil within the aforementioned range at 100°C, evaporation loss is minimized and power loss due to viscous resistance is not too significant, thus making it easier to achieve improved fuel consumption.

[0233] The lubricating oil base oil preferably has a paraffin content (sometimes recorded as %Cp) of 70% or more, more preferably 75% or more, and even more preferably 80% or more, based on ndM ring analysis.

[0234] The lubricating oil base oil has good oxidation stability and other properties when the paraffin content is within the aforementioned range.

[0235] The content of lubricating oil base oil in the lubricating oil composition is, for example, in the range of 65% to 95% by mass of the total amount of the lubricating oil composition, preferably in the range of 70% to 95% by mass, and even more preferably in the range of 70% to 90% by mass.

[0236] The lubricating oil composition of the present invention only needs to contain the defoamer and lubricating oil base oil of the present invention, and may further contain other additives.

[0237] Other additives may include ashless cleaning agents, ashless friction modifiers, wear-resistant agents, extreme pressure agents, viscosity index improvers, metal deactivators, pour point depressants, rust inhibitors, etc. These additives may be used alone or in combination of two or more.

[0238] The content of other additives can be appropriately adjusted within the range that does not impair the effect of the present invention, based on the total amount of the lubricating oil composition, typically 0.001% to 25% by mass, preferably 0.005% to 20% by mass, and more preferably 0.01% to 15% by mass.

[0239] The total content of other additives, based on the total amount of the lubricating oil composition, is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0240] Examples of ashless cleaning agents include: alkenyl succinic acid monoimide, alkenyl succinic acid diimide, and boron-modified alkenyl succinic acid imide.

[0241] Examples of ashless friction modifiers include aliphatic amines, fatty acid esters, fatty acid amides, fatty acids, aliphatic alcohols, and aliphatic ethers, which have at least one alkyl or alkenyl group with 6 to 30 carbon atoms in their molecules.

[0242] Examples of wear-resistant agents or extreme pressure agents include: sulfur-containing compounds such as zinc dithiophosphate; phosphorus-containing compounds such as phosphites, phosphates, phosphonates, and their amine or metal salts; and sulfur- and phosphorus-containing wear-resistant agents such as thiophosphites, thiophosphates, thiophosphonates, and their amine or metal salts.

[0243] Examples of viscosity index improvers include: polymethyl methacrylate, dispersed polymethyl methacrylate, olefin copolymers (e.g., ethylene-propylene copolymers), dispersed olefin copolymers, and styrene copolymers (e.g., styrene-diene copolymers, styrene-isoprene copolymers).

[0244] Examples of metal deactivators include: benzotriazole compounds, toluenetriazole compounds, imidazole compounds, and pyrimidine compounds.

[0245] Examples of pour point depressants include: ethylene-vinyl acetate copolymers, condensates of chlorinated paraffin and naphthalene, condensates of chlorinated paraffin and phenol, polymethyl methacrylate, and polyalkyl styrene.

[0246] Examples of rust inhibitors include: petroleum sulfonates, alkylbenzene sulfonates, dinonylnaphthalene sulfonates, alkenyl succinates, polyol esters, etc.

[0247] The lubricating oil composition of the present invention is preferably used for lubricating the drive unit of a machine equipped with an internal combustion engine or an electric motor.

[0248] Regarding the lubrication of the drive unit, for example in electric vehicles, the drive unit is generally an integrated unit comprising a motor, inverter, and gearbox. The gearbox is filled with the lubricating oil composition of the present invention, thereby lubricating the drive unit. Alternatively, in gasoline vehicles, the internal combustion engine, which serves as the drive unit, stores the lubricating oil composition of the present invention in an oil pan and supplies it to the cylinders via an oil pump, thereby lubricating the drive unit. The lubrication of the drive unit is not limited to these forms; the drive unit can be lubricated by filling and supplying the metal-to-metal contact areas with the lubricating oil composition of the present invention.

[0249] As for the machinery in which the lubricating oil composition of the present invention can be used, it can be used without restriction as long as it is a car (gasoline car, electric car), robot (industrial robot, entertainment robot), aircraft (airplane, helicopter), ship, various household appliances, etc., that has an internal combustion engine or electric motor.

[0250] [Example]

[0251] The present invention will now be described in detail with reference to embodiments and comparative examples.

[0252] It should be noted that the present invention is not limited to the following embodiments.

[0253] In the examples and comparative examples, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are values ​​obtained by gel permeation chromatography (GPC) and conversion to polystyrene.

[0254] The determination conditions for GPC are as follows.

[0255] [GPC Measurement Conditions]

[0256] Measurement Equipment: High-efficiency GPC device "HLC-8320GPC" manufactured by Tosoh Corporation.

[0257] Tube Column: "TSK GUARDCOLUMN SuperHZ-L" manufactured by Tosoh Corporation + "TSK gel SuperHZM-N" manufactured by Tosoh Corporation + "TSK gel SuperHZM-N" manufactured by Tosoh Corporation + "TSK gel SuperHZM-N" manufactured by Tosoh Corporation + "TSK gel SuperHZM-N" manufactured by Tosoh Corporation

[0258] Detector: RI (Differential Refractometer)

[0259] Data processing: EcoSEC Data Analysis version 1.07 manufactured by Tosoh Corporation.

[0260] Column temperature: 40℃

[0261] Developing solvent: Tetrahydrofuran

[0262] Flow rate: 0.35 mL / min

[0263] Test sample: Dissolve 7.5 mg of the sample in 10 ml of tetrahydrofuran, filter the obtained solution using a microporous filter, and use the resulting sample as the test sample.

[0264] Sample injection volume: 20 μL

[0265] Standard sample: According to the determination manual "HLC-8320GPC", use the following monodisperse polystyrene with a known molecular weight.

[0266] (Monodisperse polystyrene)

[0267] The "A-300" manufactured by Tosoh Corporation

[0268] The "A-500" manufactured by Tosoh Corporation

[0269] The "A-1000" manufactured by Tosoh Corporation

[0270] The "A-2500" manufactured by Tosoh Corporation

[0271] The "A-5000" manufactured by Tosoh Corporation

[0272] The F-1 fighter jet manufactured by Tosoh Corporation.

[0273] The F-2 manufactured by Tosoh Corporation

[0274] The F-4 manufactured by Tosoh Corporation

[0275] The F-10 manufactured by Tosoh Corporation

[0276] The F-20 manufactured by Tosoh Corporation

[0277] The F-40 manufactured by Tosoh Corporation

[0278] The F-80 manufactured by Tosoh Corporation

[0279] The F-128 manufactured by Tosoh Corporation

[0280] The F-288 manufactured by Tosoh Corporation

[0281] (Synthetic Example 1: Synthesis of Defoamer (1))

[0282] In a glass flask equipped with a stirring device, thermometer, cooling tube, and dropping device, 30 parts by mass of dipropylene glycol monomethyl ether acetate as a solvent are added, and the mixture is heated to 95°C while being stirred under a nitrogen stream.

[0283] Next, two dropping solutions were prepared by dissolving 15 parts by mass of 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane, 13.8 parts by mass of methoxy polyethylene glycol acrylate (with approximately 9 repeats of the ethylene oxide chain), and 4.5 parts by mass of polyethylene glycol dimethacrylate (with approximately 4 repeats of the ethylene oxide chain) in 37.7 parts by mass of dipropylene glycol monomethyl ether acetate, and a polymerization initiator solution prepared by dissolving 1 part by mass of tert-butyl peroxide-2-ethylhexanoate as a free radical polymerization initiator in 10 parts by mass of dipropylene glycol monomethyl ether acetate, respectively, in different dropping devices.

[0284] While keeping the inside of the flask at 95°C, the monomer solution and polymerization initiator solution were simultaneously added dropwise. The monomer solution was added dropwise over 2 hours, and the polymerization initiator solution was added dropwise over 2.5 hours. After the addition of the polymerization initiator solution was completed, the mixture was stirred at 95°C for 3 hours. Then, the temperature was raised to 110°C and stirred for 1 hour to obtain a solution of defoamer (1).

[0285] The molecular weight of the obtained defoamer (1) was determined by GPC, and the weight-average molecular weight (Mw) was 33,000.

[0286] (Synthesis Example 2: Synthesis of Defoamer (2))

[0287] In a glass flask equipped with a stirring device, thermometer, cooling pipe, and dropping device, 30 parts by mass of dipropylene glycol monomethyl ether acetate as a solvent are added, and the mixture is heated to 100°C while being stirred under a nitrogen stream.

[0288] Next, two dropping solutions were prepared by dissolving 15 parts by mass of 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane, 13.8 parts by mass of methoxy polyethylene glycol acrylate (with an ethylene oxide chain repeat number of approximately 9), and 4.5 parts by mass of trimethylolpropane triacrylate in 93.2 parts by mass of dipropylene glycol monomethyl ether acetate, and a polymerization initiator solution prepared by dissolving 1.67 parts by mass of tert-butyl peroxide-2-ethylhexanoate as a free radical polymerization initiator in 10 parts by mass of dipropylene glycol monomethyl ether acetate, respectively, in different dropping devices.

[0289] While keeping the inside of the flask at 100°C, the monomer solution and polymerization initiator solution were simultaneously added dropwise. The monomer solution was added dropwise over 2 hours, and the polymerization initiator solution was added dropwise over 2.5 hours. After the addition of the polymerization initiator solution was completed, the mixture was stirred at 100°C for 4 hours to obtain a solution of defoamer (2).

[0290] The molecular weight of the obtained defoamer (2) was determined by GPC, and the weight-average molecular weight (Mw) was 20,000.

[0291] (Synthesis Example 3: Synthesis of Defoamer (3))

[0292] In a glass flask equipped with a stirring device, thermometer, cooling tube, and dropping device, 30 parts by mass of dipropylene glycol monomethyl ether acetate as a solvent are added, and the mixture is heated to 105°C while being stirred under a nitrogen stream.

[0293] Next, two dropping solutions were prepared by dissolving 15 parts by mass of 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane, 13.8 parts by mass of methoxy polyethylene glycol acrylate (with an ethylene oxide chain repeat number of approximately 9), and 4.5 parts by mass of pentaerythritol tetraacrylate in 93.2 parts by mass of dipropylene glycol monomethyl ether acetate, and a polymerization initiator solution prepared by dissolving 1.67 parts by mass of tert-butyl peroxide-2-ethylhexanoate as a free radical polymerization initiator in 10 parts by mass of dipropylene glycol monomethyl ether acetate, respectively, in different dropping devices.

[0294] While maintaining the inside of the flask at 105°C, the monomer solution and polymerization initiator solution were simultaneously added dropwise. The monomer solution was added dropwise over 2 hours, and the polymerization initiator solution was added dropwise over 2.5 hours. After the addition of the polymerization initiator solution was completed, the mixture was stirred at 105°C for 4 hours to obtain the solution of defoamer (3).

[0295] The molecular weight of the obtained defoamer (3) was determined by GPC, and the weight-average molecular weight (Mw) was 26,000.

[0296] (Synthetic Example 4: Synthesis of Defoamer (4))

[0297] In a glass flask equipped with a stirring device, thermometer, cooling tube, and dropping device, 30 parts by mass of dipropylene glycol monomethyl ether acetate as a solvent are added, and the mixture is heated to 110°C while being stirred under a nitrogen stream.

[0298] Next, two dropping solutions were prepared by dissolving 15 parts by mass of 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane, 13.8 parts by mass of methoxy polyethylene glycol acrylate (with an ethylene oxide chain repeat number of approximately 9), and 4.5 parts by mass of dipentaerythritol hexaacrylate in 93.2 parts by mass of dipropylene glycol monomethyl ether acetate, and a polymerization initiator solution prepared by dissolving 6.66 parts by mass of tert-butyl peroxide-2-ethylhexanoate as a free radical polymerization initiator in 10 parts by mass of dipropylene glycol monomethyl ether acetate, respectively, in different dropping devices.

[0299] While maintaining the inside of the flask at 110°C, the monomer solution and polymerization initiator solution were simultaneously added dropwise. The monomer solution was added dropwise over 2 hours, and the polymerization initiator solution was added dropwise over 2.5 hours. After the addition of the polymerization initiator solution was completed, the mixture was stirred at 110°C for 4 hours to obtain a solution of defoamer (4).

[0300] The molecular weight of the obtained defoamer (4) was determined by GPC, and the weight-average molecular weight (Mw) was 13,000.

[0301] (Synthetic Example 5: Synthesis of Defoamer (5))

[0302] In a glass flask equipped with a stirring device, thermometer, cooling pipe, and dropping device, 30 parts by mass of n-butyl acetate as a solvent are added, and the mixture is heated to 100°C while being stirred under a nitrogen stream.

[0303] Next, two dropping solutions were prepared by dissolving 15 parts by mass of 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane, 13.8 parts by mass of methoxy polyethylene glycol acrylate (with an ethylene oxide chain repeat number of approximately 9), and 4.5 parts by mass of tris(2-acryloyloxyethyl)isocyanurate in 78.1 parts by mass of n-butyl acetate, and a polymerization initiator solution prepared by dissolving 1.67 parts by mass of tert-butyl peroxide-2-ethylhexanoate, which serves as a free radical polymerization initiator, in 10 parts by mass of n-butyl acetate, in separate dropping devices.

[0304] While keeping the inside of the flask at 100°C, the monomer solution and polymerization initiator solution were simultaneously added dropwise. The monomer solution was added dropwise over 2 hours, and the polymerization initiator solution was added dropwise over 2.5 hours. After the addition of the polymerization initiator solution was completed, the mixture was stirred at 100°C for 3 hours, then heated to 110°C and stirred for 1 hour to obtain the solution of defoamer (5).

[0305] The molecular weight of the obtained defoamer (5) was determined by GPC, and the weight-average molecular weight (Mw) was 14,000.

[0306] (Synthesis Example 6: Synthesis of Defoamer (6))

[0307] In a glass flask equipped with a stirring device, thermometer, cooling tube, and dropping device, 30 parts by mass of dipropylene glycol monomethyl ether acetate as a solvent are added, and the mixture is heated to 110°C while being stirred under a nitrogen stream.

[0308] Next, two dropping solutions were prepared by dissolving 12.5 parts by mass of 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane and 12.5 parts by mass of polyethylene glycol dimethacrylate (with an ethylene oxide chain repeating approximately 9 times) in 60 parts by mass of dipropylene glycol monomethyl ether acetate, and a polymerization initiator solution prepared by dissolving 7.5 parts by mass of tert-butyl peroxide-2-ethylhexanoate as a free radical polymerization initiator in 10 parts by mass of dipropylene glycol monomethyl ether acetate, respectively, in different dropping devices.

[0309] While maintaining the inside of the flask at 110°C, the monomer solution and polymerization initiator solution were simultaneously added dropwise. The monomer solution was added dropwise over 2 hours, and the polymerization initiator solution was added dropwise over 2.5 hours. After the addition of the polymerization initiator solution was completed, the mixture was stirred at 110°C for 2 hours to obtain a solution of defoamer (6).

[0310] The molecular weight of the obtained defoamer (5) was determined by GPC, and the weight-average molecular weight (Mw) was 15,000.

[0311] (Comparative Synthesis Example 1: Synthesis of Defoamer (1'))

[0312] In a glass flask equipped with a stirring device, thermometer, cooling pipe, and dropping device, 52 parts by mass of n-butyl acetate as a solvent are added, and the mixture is heated to 85°C while being stirred under a nitrogen stream.

[0313] Next, two dropping solutions were placed in different dropping devices: 30 parts by mass of 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane dissolved in 50 parts by mass of n-butyl acetate and 20 parts by mass of methoxy polyethylene glycol methacrylate (the number of repeats of the ethylene oxide chain is about 9); and a polymerization initiator solution prepared by dissolving 3 parts by mass of tert-butyl peroxide-2-ethylhexanoate, which serves as a free radical polymerization initiator, in 15 parts by mass of n-butyl acetate.

[0314] While maintaining the inside of the flask at 85°C, the monomer solution and polymerization initiator solution were added dropwise over 2 hours. After the addition was completed, the mixture was stirred at 85°C for 4 hours, and then heated to 110°C and stirred for another 1 hour to obtain a solution of defoamer (1').

[0315] The molecular weight of the obtained defoamer (1') was determined by GPC, and the weight-average molecular weight (Mw) was 40,000.

[0316] (Comparative Example 2: Synthesis of Defoamer (2'))

[0317] Except that 30 parts by mass of the compound shown in formula (1') were used instead of 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane, a solution of defoamer (2') was obtained in the same manner as in Comparative Example 1.

[0318]

[0319] (The repeated part of n is approximately 65.)

[0320] The molecular weight of the obtained defoamer (2') was determined by GPC, and the weight-average molecular weight (Mw) was 25,000.

[0321] (Comparative Example 3)

[0322] Additionally, prepare the commercially available dimethyl silicone ("KF-96-50000cs" manufactured by Shin-Etsu Silicone Co., Ltd.) as a defoamer (3').

[0323]

[0324] The defoaming performance of the manufactured defoamer was evaluated by conducting the following foaming test. The results are shown in Table 1.

[0325] (Preparation of Lubricating Oil Composition)

[0326] A lubricating oil composition is prepared by adding defoamers diluted with kerosene to 100 parts by weight of a base lubricating oil (paraffinic mineral oil) as the main component and containing small amounts of various additives (viscosity index improvers, phosphite compounds, thiadiazole compounds, calcium-based cleaning agents, metal deactivators, ashless dispersants, antioxidants, etc.) in the amounts shown in Table 1.

[0327] The obtained lubricating oil composition was subjected to the following foaming test. The results are shown in Table 1.

[0328] (Fogging test)

[0329] The foaming test was conducted according to the homogenizer method disclosed in Japanese Patent Application Publication No. 2008-120880.

[0330] Using a homogenizer (PRIMIX Co., Ltd.'s "TKLabomix") equipped with a generator shaft (PRIMIX Co., Ltd.'s "Minimixer"), the lubricating oil composition was stirred under the following conditions. The foaming amount (mL) was calculated by subtracting the oil level reading (mL) before stirring from the foaming level reading (mL) 3 seconds after stirring ended. The lower the foaming amount, the better the defoaming performance.

[0331] Speed: 16,000 rpm

[0332] Oil temperature: 80℃ or 120℃

[0333] Oil volume: 80ml

[0334] Container: 200ml graduated cylinder (inner diameter φ36mm)

[0335] Mixing time: 1 minute

[0336] [Table 1]

[0337]

[0338] According to the results in Table 1, it can be confirmed that defoamers (1) to (6) exhibit excellent defoaming properties at both 80°C and 120°C. On the other hand, sufficient defoaming properties cannot be obtained in defoamer (1') without the use of "polymeric monomer (2) having two or more polymeric unsaturated groups". Regarding defoamer (2'), defoaming properties at 80°C are obtained by introducing a polysiloxane structure, but sufficient defoaming properties are not obtained at 120°C.

Claims

1. An antifoaming agent comprising a polymer having at least a polymeric monomer (1) and a polymeric monomer (2) as polymerizing components, said polymeric monomer (1) having -Si[OSi(R)3] n [R'] 3-n The functional group shown has a polymerizable unsaturated group, namely -Si[OSi(R)3]. n [R'] 3-n In this context, n is an integer in the range of 1 to 3; R is an alkyl group with 1 to 3 carbon atoms; R' is an alkyl group with 1 to 3 carbon atoms; and the polymerizable monomer (2) has two or more polymerizable unsaturated groups.

2. The defoamer as described in claim 1, wherein, The polymerizable monomer (1) is a compound represented by the following general formula (1-1); In the general formula (1-1), R are each an alkyl group having 1 to 3 carbon atoms; R' is an alkyl group having 1 to 3 carbon atoms, and each R' is an alkyl group. L 11 It is a divalent organic group or a single bond; n is an integer in the range of 1 to 3; P represents a polymeric group as shown in general formula (P-1), general formula (P-2), or general formula (P-3); In the general formulas (P-1), (P-2), and (P-3), R 11 It can be a hydrogen atom or a methyl group; R 12 It consists of hydrogen atoms or organic groups; R 13 It can be a hydrogen atom or a methyl group; *For L 11 Bonded connection key.

3. The defoamer as described in claim 1 or 2, wherein, The content of the polymerizable monomer (1) in the polymeric component is in the range of 10% by mass or more.

4. The defoamer as described in claim 1 or 2, wherein, The polymerizable monomer (2) is a compound represented by the following general formula (2-1); In the general formula (2-1), R 21 It can be a hydrogen atom or a methyl group; x is an integer greater than or equal to 2. L 21 It is an x-valent organic group.

5. The defoamer as described in claim 1 or 2, wherein, The content of the polymerizable monomer (2) in the polymeric component is in the range of 1% to 75% by mass.

6. The defoamer as described in claim 1 or 2, wherein, The polymeric component comprises a polymerizable monomer (3), which has one or more groups selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, an aromatic group having 6 to 18 carbon atoms, a group containing a polyoxyalkylene chain, and a group containing a polyester chain.

7. The defoamer as described in claim 6, wherein, The polymerizable monomer (3) is one or more selected from the group consisting of compounds represented by the following general formula (3-1), the following general formula (3-2), the following general formula (3-3), the following general formula (3-4), and the following general formula (3-5); In the general formulas (3-1), (3-2), (3-3), (3-4), and (3-5), R 31 It can be a hydrogen atom or a methyl group. R 32 Alkyl groups having 1 to 18 carbon atoms R 33 It can be a hydrogen atom or a methyl group. R 34 It is an alkyl group having 1 to 18 hydrogen atoms or carbon atoms. R 35 It can be a hydrogen atom or a methyl group. R 36 It is an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms with an ether bond, or a hydrogen atom. R 37 It can be a hydrogen atom or a methyl group. R 38 It is an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms with an ether bond, or a hydrogen atom. L 3 It is a divalent organic group or a single bond. R 39 It can be a hydrogen atom or a methyl group. R 40 Each is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms. n is an integer in the range of 1 to 4, m represents the number of repetitions, the average of m is in the range of 1 to 200, p is an integer in the range of 1 to 10, q represents the number of repetitions, the average of q is in the range of 1 to 100, and l is an integer in the range of 0 to 5.

8. The defoamer as described in claim 7, wherein, The polymerizable monomer (3) comprises a compound represented by the general formula (3-2).

9. The defoamer as described in claim 6, wherein, The content of the polymerizable monomer (3) in the polymeric component is in the range of 0% to 75% by mass.

10. The defoamer according to claim 1 or 2, wherein the weight-average molecular weight is in the range of 2,000 to 200,000.

11. A lubricating oil composition comprising a lubricating oil base oil and the defoamer of claim 1.

12. The lubricating oil composition of claim 11, used for lubricating the drive portion of a machine equipped with an internal combustion engine or an electric motor.

13. The lubricating oil composition of claim 11, used for lubricating the drive unit of a vehicle equipped with an internal combustion engine or an electric motor.

14. A machine that uses the lubricating oil composition of claim 11 in a drive unit.

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