JP2019052223A - An ashless detergent dispersant and a lubricant composition - Google Patents

Abstract

To provide the ashless detergent dispersant and the lubricant composition using the ashless detergent dispersant, wherein the ashless detergent dispersant contains a polymer that maintains stable dispersion performance even in a high temperature environment and exhibits sufficient solubility in a lubricant and easy handling.SOLUTION: The ashless detergent dispersant comprises polymers having a weight average molecular weight (Mw) of 200,000 or less, wherein the polymer is formed by polymerizing a specific maleimide monomer as an essential component as a monomer component. The lubricant composition also contains lubricant base oil and the ashless detergent dispersant. Furthermore, a method of producing the ashless detergent dispersant comprises a polymer having the weight average molecular weight (Mw) of 200,000 or less formed by polymerizing the specific maleimide monomer as the essential component as the monomer component.SELECTED DRAWING: None

Description

  The present invention relates to an ashless detergent / dispersant having a specific structure, and a lubricating oil composition containing the same. In particular, the present invention relates to an ashless detergent / dispersant that maintains stable dispersion performance even in a high-temperature environment and exhibits sufficient solubility in lubricating oil and easy handling.

As part of recent global environmental protection measures, there is a need for enhanced fuel economy and exhaust gas purification performance for automobiles. In connection with this, the lubricating oil for automobiles is also required to have performance capable of realizing improvement in fuel efficiency and exhaust gas purification performance in an internal combustion engine.
Countermeasures against environmental pollution caused by nitrogen oxides (NOx) and particulate emissions (PM) in exhaust gas from internal combustion engines have become important issues in recent years, and there is an urgent need to reduce them. For example, there is a method of increasing the exhaust gas recirculation rate or reducing the combustion peak temperature by delaying the fuel injection timing.
However, if the combustion peak temperature is lowered, black smoke and PM increase, so an exhaust gas aftertreatment device is essential. The use of PM traps and oxidation catalysts for exhaust gas after-treatment devices is being considered, but since these generally have a filter-like structure, deposits are generated by the metal content in automotive lubricating oil. If this happens, the filter is clogged (blocked), which is a problem.
Conventionally, in lubricating oils for internal combustion engines, metal-based and ashless-based are used in combination as detergent dispersants, and as metal-based detergent dispersants, generally alkali metal or alkaline earth metal sulfonates, phenates, salicylates, Phosphonates and their overbased compounds are used, but it is necessary to reduce the metal content in the lubricating oil to suppress the deposits. Development of an ashless detergent / dispersant that can reduce the amount of water is being promoted (Patent Documents 1 to 5).

JP 7-316576 A Japanese Patent No. 5400612 Japanese Patent No. 4212751 JP 2006-291042 A Special table 2013-512955 gazette

  However, many of the ashless detergents and dispersants developed so far have not been sufficiently effective in suppressing oxidative degradation and maintaining base number in high temperature environments. Further, there is room for improvement in the solubility in lubricating base oil and the handleability due to the viscosity of the dispersant itself, and further improvements are desired.

  The present invention has been made in view of the above problems, and its purpose is to maintain a stable dispersion performance even in a high temperature environment, and to contain a polymer exhibiting sufficient solubility in lubricating oil and easy handling. It is intended to provide an ashless detergent / dispersant and a lubricating oil composition using the ashless detergent / dispersant.

  As a result of intensive studies, the present inventors have found an ashless detergent / dispersant containing a specific polymethacrylate polymer having a ring structure in the main chain, and further a lubricating oil composition, and have reached the present invention.

That is, the present invention provides a polymer obtained by polymerizing, as a monomer component, (a) a maleimide monomer represented by the following general formula (1) (hereinafter referred to as “component (a)”) as an essential component. And an ashless detergent / dispersant in which the polymer has a weight average molecular weight (Mw) of 200,000 or less.

（式中、Ｒ¹ 及びＲ² はそれぞれ独立に、水素原子またはアルキル基であり、Ｘは水素原子、直鎖状、環状、分岐状のアルキル基（芳香環を有するアルキル基を含む）またはアリール基である。）
該重合体が、（ａ）成分に加え、（ｂ）炭素数が６〜４０の脂肪族炭化水素基を有するアルキル（メタ）アクリレート（以下、「（ｂ）成分」と称する）、及び（ｃ）炭素数が１〜５の脂肪族炭化水素基を有するアルキル（メタ）アクリレート（以下、「（ｃ）成分」と称する）を必須成分として重合してなる重合体であることが好ましい。
該重合体１００質量部に対し、（ａ）成分由来の単位が５質量部以上５０質量部以下であることが好ましい。
該重合体１００質量部に対し、（ｂ）成分由来の単位が５０質量部以上９５質量部未満であることが好ましい。

Wherein R ¹ and R ² are each independently a hydrogen atom or an alkyl group, and X is a hydrogen atom, a linear, cyclic or branched alkyl group (including an alkyl group having an aromatic ring) or aryl Group.)
In addition to the component (a), the polymer comprises (b) an alkyl (meth) acrylate having an aliphatic hydrocarbon group having 6 to 40 carbon atoms (hereinafter referred to as “component (b)”), and (c) It is preferably a polymer obtained by polymerizing an alkyl (meth) acrylate having an aliphatic hydrocarbon group having 1 to 5 carbon atoms (hereinafter referred to as “component (c)”) as an essential component.
It is preferable that the unit derived from the component (a) is 5 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the polymer.
The unit derived from component (b) is preferably 50 parts by mass or more and less than 95 parts by mass with respect to 100 parts by mass of the polymer.

  Moreover, this invention is a lubricating oil composition containing the said ashless type | system | group detergent dispersing agent.

  In addition, as a monomer component, (a) a maleimide monomer represented by the following general formula (1) (hereinafter referred to as “component (a)”) is polymerized as an essential component, and a weight average molecular weight (Mw) ) Is also a method for producing an ashless detergent-dispersant containing a polymer of 200,000 or less.

（式中、Ｒ¹ 及びＲ² はそれぞれ独立に、水素原子またはアルキル基であり、Ｘは水素原子、直鎖状、環状、分岐状のアルキル基（芳香環を有するアルキル基を含む）またはアリール基である。）
さらに、 単量体成分として、（ａ）下記一般式（１）で示されるマレイミド系単量体（以下、「（ａ）成分」と称する）を必須成分として重合してなり重量平均分子量（Ｍｗ）が２０万以下である重合体の無灰系清浄分散剤としての使用方法でもある。

Wherein R ¹ and R ² are each independently a hydrogen atom or an alkyl group, and X is a hydrogen atom, a linear, cyclic or branched alkyl group (including an alkyl group having an aromatic ring) or aryl Group.)
Further, as a monomer component, (a) a maleimide monomer represented by the following general formula (1) (hereinafter referred to as “component (a)”) is polymerized as an essential component, and a weight average molecular weight (Mw) ) Is a method of using a polymer having an amount of 200,000 or less as an ashless detergent-dispersant.

（式中、Ｒ¹ 及びＲ² はそれぞれ独立に、水素原子またはアルキル基であり、Ｘは水素原子、直鎖状、環状、分岐状のアルキル基（芳香環を有するアルキル基を含む）またはアリール基である。）

Wherein R ¹ and R ² are each independently a hydrogen atom or an alkyl group, and X is a hydrogen atom, a linear, cyclic or branched alkyl group (including an alkyl group having an aromatic ring) or aryl Group.)

  By using the ashless detergent / dispersant of the present invention, heat resistance and dispersibility in a high temperature environment can be improved as compared with conventional lubricating oil compositions. Further, since the ashless detergent / dispersant of the present invention exhibits an effect even when added in a smaller amount, various lubricating oils, particularly engines, are maintained while maintaining sufficient solubility in the lubricating base oil and easy handling. It can be suitably used for oil (for gasoline, diesel, etc.).

(A) And (b) is a figure which shows an evaluation result.

The present invention is described in detail below. In the following description, “part” means “part by mass” and “%” means “mass%” unless otherwise specified. In addition, “A to B” indicating a range indicates that the range is A or more and B or less.
Among the monomer components used for the synthesis of the polymer contained in the ashless detergent / dispersant of the present invention, the component (a) is a maleimide monomer represented by the following general formula (1).

（式中、Ｒ¹ 及びＲ² はそれぞれ独立に、水素原子またはアルキル基であり、Ｘは水素原子、直鎖状、環状、分岐状のアルキル基（芳香環を有するアルキル基を含む）またはアリール基である。）
単量体（ａ）成分の具体例としては、マレイミド、Ｎ−メチルマレイミド、Ｎ−エチルマレイミド、Ｎ−イソプロピルマレイミド、Ｎ−ブチルマレイミド、Ｎ−イソブチルマレイミド、Ｎ−ターシャリブチルマレイミド、Ｎ−シクロヘキシルマレイミド、Ｎ−ラウリルマレイミド、Ｎ−ステアリルマレイミド、Ｎ−フェニルマレイミド、Ｎ−ベンジルマレイミド、Ｎ−クロロフェニルマレイミド、Ｎ−メチルフェニルマレイミド、Ｎ−ナフチルマレイミド、Ｎ−ヒドロキシルエチルマレイミド、Ｎ−ヒドロキシルフェニルマレイミド、Ｎ−メトキシフェニルマレイミド、Ｎ−カルボキシフェニルマレイミド、Ｎ−ニトロフェニルマレイミド、Ｎ−トリブロモフェニルマレイミドなどが挙げられる。これらの中でも入手性や経済性の観点および基油への溶解性が高いことから、Ｎ−フェニルマレイミド、Ｎ−シクロヘキシルマレイミド、Ｎ−イソプロピルマレイミド、Ｎ−ベンジルマレイミド、Ｎ−ラウリルマレイミド、Ｎ−ステアリルマレイミドが好ましいが、Ｎ−フェニルマレイミドが特に好ましい。なお、上記単量体（ａ）は単独で使用してもよいし、２種以上を併用してもよい。

Wherein R ¹ and R ² are each independently a hydrogen atom or an alkyl group, and X is a hydrogen atom, a linear, cyclic or branched alkyl group (including an alkyl group having an aromatic ring) or aryl Group.)
Specific examples of the monomer (a) component include maleimide, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, N-tertiarybutylmaleimide, N-cyclohexyl Maleimide, N-laurylmaleimide, N-stearylmaleimide, N-phenylmaleimide, N-benzylmaleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-naphthylmaleimide, N-hydroxylethylmaleimide, N-hydroxylphenylmaleimide, N-methoxyphenyl maleimide, N-carboxyphenyl maleimide, N-nitrophenyl maleimide, N-tribromophenyl maleimide and the like can be mentioned. Of these, N-phenylmaleimide, N-cyclohexylmaleimide, N-isopropylmaleimide, N-benzylmaleimide, N-laurylmaleimide, N-stearyl are highly available and economical and have high solubility in base oils. Maleimide is preferred, but N-phenylmaleimide is particularly preferred. In addition, the said monomer (a) may be used independently and may use 2 or more types together.

  The content of the monomer (a) component is preferably 2 to 50 parts by mass, more preferably 5 to 40 parts by mass, particularly preferably 100 parts by mass in total for all monomer components. Is 10 parts by mass or more and 35 parts by mass or less. The ashless detergent-dispersant containing the polymer using the monomer (a) component in the above numerical range can maintain stable dispersion performance even in a high temperature environment.

The monomer (b) component used in the present invention has a structure represented by the following general formula (2), and R ^{3 in} the formula is a hydrogen atom or a methyl group, and R ⁴ is carbon. Examples thereof include (meth) acrylates having an alkyl group of 6 to 40, preferably 6 to 24, particularly preferably 12 to 24. R ⁴ may be linear, cyclic or branched, and may have a substituent.

単量体（ｂ）成分は、Ｒ^３及びＲ^４がそれぞれ単一の単量体であってもよく、Ｒ^３及び／又はＲ^４が異なる２種以上の単量体の混合物であってもよい。反応性の点から、Ｒ^３は水素原子又はメチル基であることが好ましい。

The monomer (b) component may be such that R ³ and R ⁴ are each a single monomer, or a mixture of two or more monomers in which R ³ and / or R ⁴ are different. Good. From the viewpoint of reactivity, R ³ is preferably a hydrogen atom or a methyl group.

  Specific examples of the monomer (b) component include n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (Meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, stearyl (meth) acrylate, nonadecyl (meta) ) Acrylate, eicosyl (meth) acrylate, behenyl (meth) acrylate, tetracosyl (meth) acrylate, 2-decyltetradecyl (meth) acrylate, cyclohexyl (meth) acrylate, Menthyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, adamantyl (meth) acrylate, etc. are mentioned. Among these, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, eicosyl (meth) acrylate, behenyl (meta) from the viewpoints of availability and economy and high solubility in base oils. ) Acrylate, tetracosyl (meth) acrylate, 2-decyltetradecyl (meth) acrylate, and cyclohexyl (meth) acrylate are preferred. In addition, the said monomer (b) may be used independently and may use 2 or more types together.

  The content of the monomer (b) component is preferably 50 parts by weight or more and less than 95 parts by weight, more preferably 50 parts by weight or more and 93 parts by weight or less, particularly preferably 100 parts by weight of the total of all monomer components. Is 50 parts by mass or more and 90 parts by mass or less. The ashless detergent-dispersant containing the polymer using the monomer (b) component in the above numerical range has good solubility in base oils having various compositions.

Specifically, the monomer (c) component has a structure represented by the following general formula (3), R ^{5 in} the formula is a hydrogen atom or a methyl group, and R ⁶ is carbon. (Meth) acrylates that are aliphatic hydrocarbon groups of 1 to 5 are mentioned. R ⁶ may be linear, cyclic or branched, and may have a substituent.

単量体（ｃ）成分は、Ｒ^５及びＲ^６がそれぞれ単一の単量体であってもよく、Ｒ^５及び／又はＲ^６が異なる２種以上の単量体の混合物であってもよい。反応性の点から、Ｒ^５は水素原子又はメチル基であることが好ましい。また、粘度指数向上の点から、Ｒ^６は直鎖状または分岐状であることが好ましい。

Monomer component (c) may be a mixture of R ⁵ and R ⁶ each may be a single monomer, R ⁵ and / or R ⁶ are different 2 or more monomers Good. From the viewpoint of reactivity, R ⁵ is preferably a hydrogen atom or a methyl group. In view of improving the viscosity index, R ⁶ is preferably linear or branched.

  Specific examples of the monomer (c) component include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, and n-butyl (meth) acrylate. , Iso-butyl (meth) acrylate, t-butyl (meth) acrylate, n-amyl (meth) acrylate, iso-amyl (meth) acrylate, t-amyl (meth) acrylate, neopentyl (meth) acrylate, and the like. . Among them, it is preferable that at least methyl (meth) acrylate is included as the monomer (c) component. In addition, the said monomer (c) may be used independently and may use 2 or more types together.

  The content of the monomer (c) component is preferably 2 to 40 parts by mass, more preferably 5 to 35 parts by mass, particularly preferably 100 parts by mass in total of all monomer components. Is 5 parts by mass or more and 30 parts by mass or less. When the content of the monomer (c) component is in the above range, the compatibility with other components and copolymerization are good, the polymerization rate is good, the polymerization rate is high, and the productivity is good.

  Moreover, as a monomer component which synthesize | combines the polymer of this invention, radically polymerizable monomers (d) other than (a), (b), (c) component can be contained. The monomer (d) can be classified into a monofunctional monomer having one radical polymerizable group in the same molecule and a polyfunctional monomer having two or more radical polymerizable groups in the same molecule. .

  Examples of monofunctional monomers include (b) and other (meth) acrylates other than component (c), unsaturated mono- or dicarboxylic esters, unsaturated carboxylic acids, vinyl aromatics, vinyl esters, vinyl ethers, Examples include olefins, vinyl cyanide, N-vinyl compounds, (meth) acrylamide, and the like. These monofunctional monomers may be used alone or in combination of two or more.

  Examples of other (meth) acrylates other than the component (b) and the component (c) include benzyl (meth) acrylate, phenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxybutyl (meth). Acrylate, 2-methoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, morpholinoalkylene (meth) acrylate, α-hydroxymethyl acrylate methyl, polyethylene glycol mono (Meth) acrylate etc. are mentioned.

Examples of the unsaturated mono- or dicarboxylic acid ester include butyl crotonate, octyl crotonate, dibutyl maleate, dilauryl maleate, dioctyl fumarate, distearyl fumarate, and the like.
Examples of the unsaturated carboxylic acids include (meth) acrylic acid, maleic acid, fumaric acid, maleic anhydride and the like.

  Examples of the vinyl aromatic compound include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, and methoxystyrene, 2-vinylpyridine, 4-vinylpyridine, and the like.

  Examples of the vinyl ester include vinyl acetate, vinyl propionate, vinyl octylate and the like.

Examples of the vinyl ether include methyl vinyl ether, butyl vinyl ether, octyl vinyl ether, dodecyl vinyl ether, and the like.
Examples of olefins include ethylene, propylene, 1-butene, isobutene, 1-tetradecene, 1-octadecene, diisobutene and the like.

  Examples of vinyl cyanide include acrylonitrile and methacrylonitrile.

  Examples of the N-vinyl compound include N-vinyl pyrrolidone, N-vinyl caprolactam, N-vinyl imidazole, N-vinyl morpholine, N-vinyl acetamide and the like.

  Examples of (meth) acrylamide include N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dibutyl (meth) acrylamide, N-methylol (meth) acrylamide, and acryloylmorpholine. Etc.

  Among these monofunctional monomers, 2-hydroxyethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, methyl α-hydroxymethyl acrylate, N-vinylpyrrolidone, N, N-dimethyl ( Meth) acrylamide and acryloylmorpholine are preferred.

  The unit derived from the monofunctional monomer contained in the radical polymerizable monomer (d) other than the essential components (a), (b) and (c) is 0 part by mass with respect to 100 parts by mass of the polymer. It is 30 parts by mass or less, preferably 0 parts by mass or more and 25 parts by mass or less, and more preferably 0 parts by mass or more and 20 parts by mass or less.

  Examples of polyfunctional monomers include polyfunctional (meth) acrylates, vinyl ether group-containing (meth) acrylates, allyl group-containing (meth) acrylates, polyfunctional (meth) acryloyl group-containing isocyanurates, polyfunctional urethanes (meth). Examples include polyfunctional (meth) acrylic compounds such as acrylates, polyfunctional maleimide compounds, polyfunctional vinyl ethers, polyfunctional allyl compounds, polyfunctional aromatic vinyls, and the like. In addition, the said polyfunctional monomer may be used independently and may use 2 or more types together.

  Examples of the polyfunctional (meth) acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, and bisphenol A alkylene oxide di (meth). Acrylate, trimethylolpropane tri (meth) acrylate, 2,2 ′-[oxybis (methylene)] bisacrylic acid, dialkyl-2,2 ′-[oxybis (methylene)] bis-2-propenoate, and the like.

  Examples of the vinyl ether group-containing (meth) acrylate include 2-vinyloxyethyl (meth) acrylate, 4-vinyloxybutyl (meth) acrylate, 2- (vinyloxyethoxy) ethyl (meth) acrylate, and the like.

  Examples of the allyl group-containing (meth) acrylate include, for example, allyl (meth) acrylate, methyl α-allyloxymethyl acrylate, stearyl α-allyloxymethyl acrylate, α-allyloxymethyl acrylate 2-decyltetradecyl etc. Is mentioned.

  Examples of the polyfunctional (meth) acryloyl group-containing isocyanurate include tri (acryloyloxyethyl) isocyanurate, tri (methacryloyloxyethyl) isocyanurate, and the like.

  Examples of the polyfunctional urethane (meth) acrylate include polyfunctional isocyanates such as tolylene diisocyanate, isophorone diisocyanate, and xylylene diisocyanate, and hydroxyl groups such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. The polyfunctional urethane (meth) acrylate obtained by reaction with containing (meth) acrylic acid ester, etc. are mentioned.

  Examples of the polyfunctional maleimide compound include 4,4′-diphenylmethane bismaleimide, m-phenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, 1,6-bismaleimide- (2,2,4-trimethyl) hexane, and the like. Can be mentioned.

  Examples of the polyfunctional vinyl ether include ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, trimethylolpropane trivinyl ether, and the like.

  Examples of polyfunctional allyl compounds include ethylene glycol diallyl ether, diethylene glycol diallyl ether, polyethylene glycol diallyl ether, hexanediol diallyl ether, bisphenol A alkylene oxide diallyl ether, trimethylolpropane triallyl ether, and ditrimethylolpropane tetraallyl ether. Polyfunctional allyl ethers; polyfunctional allyl group-containing isocyanurates such as triallyl isocyanurate; polyfunctional allyl esters such as diallyl phthalate and diallyl diphenate; bisallyl nadiimide compounds; bisallyl nadiimide compounds and the like .

Examples of the polyfunctional aromatic vinyl include divinylbenzene.
The unit derived from the polyfunctional monomer contained in the radical polymerizable monomer (d) other than the essential components (a), (b) and (c) is 0 part by mass with respect to 100 parts by mass of the polymer. It is preferably 5 parts by mass or less, more preferably 0 parts by mass or more and 3 parts by mass or less, and still more preferably 0 parts by mass or more and 2 parts by mass or less.

  If the unit derived from the polyfunctional monomer exceeds the above range, gelation may proceed during polymerization, or the solubility of the ashless detergent-containing dispersant containing the polymer in the base oil may be reduced. .

  The polymerization method of the monomer component may be any of bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and the like, but is not particularly limited. When using a dispersion medium, an emulsifier, a dispersant, etc., there is no particular limitation and a known one can be used.

  The polymer contained in the ashless detergent / dispersant of the present invention preferably has a weight average molecular weight (Mw) of 200,000 or less. More preferably, it is not less than 50,000 and not more than 150,000. More preferably, it is 10,000 or more and 100,000 or less. Particularly preferably, it is 15,000 or more and 100,000 or less. Most preferably, it is 18,000 or more and 100,000 or less. The remarkable effect is 18,000 to 50,000. When the weight average molecular weight of the polymer is less than the lower limit, desired heat resistance and dispersion performance may not be obtained. When the weight average molecular weight of the polymer is excessively large, the solubility of the ashless detergent / dispersant in the base oil may be insufficient, or the handleability may deteriorate due to thickening.

  A known method can be used as a method for controlling the molecular weight. For example, it can be controlled by adjusting the amount and type of the polymerization initiator / polymerization catalyst, the polymerization temperature, and the type and amount of the chain transfer agent.

  Living Radical Polymerization can also be used as a method for controlling the molecular weight distribution. As specific methods, RAFT method, NMP method, ATRP method and the like are well known. Details are outlined in Aldrich Material Matters Volume 5, Number 1, 2010. As examples of use, for example, in the case of the RAFT method, JP-A 2012-197399 uses 2,2-azobisisobutyronitrile as a polymerization initiator and cumyl dithiobenzoate as a polymerization catalyst.

  The polymerization temperature at the time of polymerizing the monomer component may be appropriately set according to the polymerization mechanism, the type and amount of the monomer used, the type and amount of the polymerization initiator / polymerization catalyst, and the like. Although it is not, 0 to 200 degreeC is preferable and 25 to 150 degreeC is especially preferable. If the polymerization temperature is less than 0 ° C., the polymerization reaction is very slow, and if it exceeds 200 ° C., the reaction is so intense that it is difficult to control.

  The content of the polymer contained in the ashless detergent / dispersant of the present invention in the ashless detergent / dispersant is not particularly limited as long as the effects of the present invention are not impaired, but 100 parts by mass of the ashless detergent / dispersant Is preferably 50 parts by mass or more, more preferably 80 parts by mass or more, particularly preferably 90 parts by mass or more, and most preferably 95 parts by mass or more.

  The solvent used for the polymerization is not particularly limited as long as it is inactive to the polymerization reaction, the polymerization mechanism, the type and amount of the monomer used, the type and amount of the polymerization initiator / polymerization catalyst, etc. However, from the viewpoint of ensuring the solubility of the polymer and easy replacement of the solvent with the base oil after polymerization, toluene, xylene, hexane, cyclohexane, methyl ethyl ketone, and tetrahydrofuran are used. preferable. A lubricating base oil can also be suitably used as the solvent. In this case, solvent replacement after polymerization is unnecessary, and the process is simplified, which is more preferable. These solvents may be used alone or in combination of two or more. The amount of the solvent used is not particularly limited, but is preferably such that the concentration of the total amount of the monomer component, the polymerization initiator, and other components is 20% by mass or more and 100% by mass or less of the whole.

As said lubricating base oil, a mineral base oil or a synthetic base oil can be mentioned preferably. As a preferable specific example of the mineral base oil, the following oils (1) to (7) are used as raw materials, and the raw oil and / or the lubricating oil fraction recovered from the raw oils are obtained by a predetermined refining method. The base oil obtained by refine | purifying and collect | recovering lubricating oil fractions can be mentioned. Considering that it is easy to improve the quality of the obtained lubricating oil additive, the lubricating base oil may be a base oil selected from (1) to (7) or a lubricating oil fraction recovered from the base oil. The following base oil (8) or (9) obtained by performing a predetermined treatment on is preferably used.
(1) Distilled oil (WVGO) by distillation under reduced pressure of paraffin base crude oil and / or mixed base crude oil at atmospheric distillation residue
(2) Wax (such as slack wax) obtained by the lubricant dewaxing process and / or synthetic wax (Fischer-Tropsch wax, GTL wax, etc.) obtained by the gas-liquid (GTL) process, etc.
(3) One or two or more mixed oils selected from base oils (1) to (2) and / or mild hydrocracked oils of the mixed oils (4) selected from base oils (1) to (3) 2 or more kinds of mixed oils (5) Base oils (1) to (4)
(6) Mild hydrocracking treatment oil (MHC) of base oil (5)
(7) Two or more mixed oils selected from base oils (1) to (6) (8) A base oil selected from the above base oils (1) to (7) or a lubricating oil fraction recovered from the base oil Hydrocrack the fraction, and perform dewaxing treatment such as solvent dewaxing or catalytic dewaxing on the product or lubricating oil fraction recovered from the product by distillation or the like, or distill after the dewaxing treatment Hydrocracked mineral oil obtained by
(9) A base oil selected from the base oils (1) to (7) or a lubricating oil fraction recovered from the base oil is hydroisomerized and recovered from the product or the product by distillation or the like. Hydroisomerized mineral oil obtained by subjecting the lubricating oil fraction to dewaxing treatment such as solvent dewaxing or catalytic dewaxing, or distillation after the dewaxing treatment.

Synthetic base oils include poly α-olefins or hydrides thereof, isobutene oligomers or hydrides thereof, isoparaffins, alkylbenzenes, alkylnaphthalenes, diesters (ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridec Decyl adipate, di-2-ethylhexyl sebacate, etc.), polyol ester (trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyoxyalkylene glycol, dialkyl Examples thereof include diphenyl ether and polyphenyl ether, and among them, poly α-olefin is preferable. As the poly α-olefin, typically, an oligomer or co-oligomer (1-octene oligomer, decene oligomer, ethylene-propylene co-oligomer, etc.) having 2 to 32 carbon atoms, preferably 6 to 16 carbon atoms, and those. Of the hydrides. The kinematic viscosity at 100 ° C. of the synthetic base oil is preferably 1 to ²⁰ mm ² / s.

  The decomposition start temperature of the ashless detergent / dispersant is preferably 220 ° C. or higher and 500 ° C. or lower, more preferably 240 ° C. or higher and 450 ° C. or lower, still more preferably 260 ° C. or higher and 400 ° C. or lower, particularly preferably. Is 280 ° C. or higher and 380 ° C. or lower. Due to the improvement in heat resistance, the dispersion performance under a high temperature environment is improved. On the other hand, when the heat resistance is excessively improved, the solubility in the base oil tends to be insufficient.

  The present invention is also a lubricating oil composition comprising the above ashless detergent / dispersant of the present invention. The lubricating oil composition of the present invention contains a lubricating base oil and the above-described ashless detergent / dispersant of the present invention as essential components. More preferably, it contains at least one additive selected from a pour point depressant, an antiwear agent, a viscosity index improver, an antioxidant, a corrosion inhibitor, a defoamer and a friction modifier.

  As the lubricating base oil according to the present embodiment, the base oil selected from the base oils (1) to (7) described as the above-described polymer reaction solvent or the lubricating oil fraction recovered from the base oil is described above. The base oil (8) or (9) obtained by performing the treatment is particularly preferred.

Further, the above-described synthetic base oil may be used as the lubricating base oil according to the present embodiment.
The viscosity index of the lubricating base oil according to the present embodiment is preferably 100 or more, more preferably 120 to 160. When the viscosity index is less than the above lower limit, not only the viscosity-temperature characteristics, thermal / oxidative stability, and volatilization prevention properties deteriorate, but also the friction coefficient tends to increase, and the wear prevention properties decrease. There is a tendency. On the other hand, when the viscosity index exceeds the above upper limit, the low-temperature viscosity characteristics tend to deteriorate.
In addition, the viscosity index as used in the field of this invention means the viscosity index measured based on JISK2283.

  In the lubricating oil composition according to the present embodiment, the lubricating base oil according to the present embodiment may be used alone, and the lubricating base oil according to the present embodiment may be one of other base oils or You may use together with 2 or more types. In addition, when using together the lubricating base oil which concerns on this embodiment, and another base oil, the ratio of the said lubricating base oil (8) which occupies in those mixed base oils is 30 mass% or more. Preferably, it is 50 mass% or more, and more preferably 70 mass% or more.

  In the lubricating oil composition according to the present embodiment, the content of the above-described ashless detergent / dispersant of the present invention is preferably 0.01% by mass or more and 10% by mass or less based on the total amount of the lubricating oil composition. More preferably, it is 0.02 mass% or more and 5 mass% or less, More preferably, it is 0.02 mass% or more and 2 mass% or less.

  As the pour point depressant, any pour point depressant used for lubricating oil can be used. Examples include polymethacrylates, naphthalene-chlorinated paraffin condensation products, phenol-chlorinated paraffin condensation products, and the like. Among these, addition of polymethacrylates is preferable.

  As the antiwear agent (or extreme pressure agent), any antiwear agent / extreme pressure agent used for lubricating oil can be used. For example, sulfur-based, phosphorus-based, sulfur-phosphorus extreme pressure agents and the like can be used. Specifically, zinc dialkyldithiophosphate (ZnDTP), phosphites, thiophosphites, dithiophosphites Acid esters, trithiophosphites, phosphate esters, thiophosphate esters, dithiophosphate esters, trithiophosphate esters, amine salts thereof, metal salts thereof, derivatives thereof, dithiocarbamate, zinc dithio Carbamate, MoDTC, disulfides, polysulfides, sulfurized olefins, sulfurized fats and oils, and the like can be given. Among these, addition of a sulfur-based extreme pressure agent is preferable, and sulfurized fats and oils are particularly preferable.

  As the viscosity index improver, any viscosity index improver used for lubricating oils can be used. Specifically, it is a non-dispersed or dispersed ester group-containing viscosity index improver, such as a non-dispersed or dispersed poly (meth) acrylate viscosity index improver, a non-dispersed or dispersed olefin- (meth). Examples include acrylate copolymer viscosity index improvers, styrene-maleic anhydride copolymer viscosity index improvers, and mixtures thereof. Among these, non-dispersed or dispersed poly (meth) acrylate viscosity index improvers It is preferable that A non-dispersed or dispersed polymethacrylate viscosity index improver is particularly preferable. In addition, a non-dispersed or dispersed ethylene-α-olefin copolymer or a hydrogenated product thereof, polyisobutylene or a hydrogenated product thereof, a styrene-diene hydrogenated copolymer, a polyalkylstyrene, and the like can be given.

  Examples of the antioxidant include ashless antioxidants such as phenols and amines, and metal antioxidants such as copper and molybdenum. Specifically, for example, as a phenol-based ashless antioxidant, 4,4′-methylenebis (2,6-di-tert-butylphenol), 4,4′-bis (2,6-di-tert- Butylphenol) and the like are amine-based ashless antioxidants such as phenyl-α-naphthylamine, alkylphenyl-α-naphthylamine, and dialkyldiphenylamine.

  Examples of the corrosion inhibitor include benzotriazole, tolyltriazole, thiadiazole, or imidazole compounds.

Examples of the defoaming agent include silicone oil having a kinematic viscosity at 25 ° C. of 1000 to 100,000 mm ² / s, fluorosilicone oil, alkenyl succinic acid derivative, ester of polyhydroxy aliphatic alcohol and long chain fatty acid, methyl salicy Rate and o-hydroxybenzyl alcohol.

  As friction modifiers, in addition to organic molybdenum compounds such as succinimide molybdenum complexes such as molybdenum dithiocarbamate and molybdenum dithiophosphate, and amine salts of organic molybdic acid, linear alkyl and metal having 8 to 30 carbon atoms as a basic structure. And having a polar group that can be adsorbed on the same molecule in the same molecule. Examples of polar groups include amines, polyamines, amides, urea compounds and alkenyls such as amine compounds, fatty acid esters, fatty acid amides, fatty acids, fatty alcohols, aliphatic ethers, urea compounds, hydrazide compounds having these simultaneously in the molecule. Examples thereof include succinimide type, ester, alcohol and diol, or monoalkyl glycerol ester having ester and hydroxyl group at the same time. In addition, there are various types such as an alkylamine afucosyl alcohol having an amine and a hydroxyl group in the same molecule.

  When the lubricating oil composition according to this embodiment contains one or more of a pour point depressant, an antiwear agent, a viscosity index improver, an antioxidant, a corrosion inhibitor, a defoamer, and a friction modifier. Each content is preferably 0.01% by mass or more and 10% by mass or less based on the total amount of the lubricating oil composition. Moreover, when the lubricating oil composition according to the present embodiment contains an antifoaming agent, the content is preferably 0.0001% by mass or more and 0.01% by mass or less.

  Further, the lubricating oil composition according to the present embodiment contains, in addition to the above components, an ashless detergent / dispersant other than the polymer of the present invention, a metal detergent / dispersant, a demulsifier, a metal deactivator, and the like. Furthermore, it can contain.

  Examples of the metal detergent / dispersant include normal salts or basic salts such as alkali metal / alkaline earth metal sulfonate, alkali metal / alkaline earth metal phenate, and alkali metal / alkaline earth metal salicylate. Examples of the alkali metal include sodium and potassium, and examples of the alkaline earth metal include magnesium, calcium and barium. Magnesium or calcium is preferable, and calcium is more preferable.

  Examples of the demulsifier include polyalkylene glycol nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, or polyoxyethylene alkyl naphthyl ether.

  Examples of metal deactivators include imidazoline, pyrimidine derivatives, alkylthiadiazoles, mercaptobenzothiazoles, benzotriazoles or derivatives thereof, 1,3,4-thiadiazole polysulfide, 1,3,4-thiadiazolyl-2,5-bis. Examples thereof include dialkyldithiocarbamate, 2- (alkyldithio) benzimidazole, and β- (o-carboxybenzylthio) propiononitrile.

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. In addition,% and part in an Example and a comparative example represent the mass% and a mass part.
(Weight average molecular weight)
-Equipment: Tosoh GPC system HLC-8320GPC ECOSEC
-Column: manufactured by Tosoh Corporation, two TSKgel GMHXL-developing solvent: tetrahydrofuran-flow rate of developing solvent: 1.0 ml / min-standard sample: TSK standard polystyrene (PS-oligomer kit manufactured by Tosoh Corporation)
-Column temperature: 40 ° C
-Sample concentration: 0.5%
Injection volume: 200 μl

(Decomposition start temperature)
-Apparatus: Differential type differential thermal balance (ThermoPlus2 TG-8120, Dynamic TG, manufactured by Rigaku Corporation)
-Measurement conditions: Sample amount 10 mg
-Temperature increase rate: 10 ° C / min-Atmosphere: Nitrogen flow 200ml / min-Control method: Step-like isothermal control method (mass decrease rate value within the range from 150 ° C to 500 ° C is controlled to 0.005% / sec or less )

(Base oil solubility)
For the base oil solution having a polymer concentration of 30% by mass, “◯” or “x” was determined according to the following criteria.
◯: At 25 ° C., the solution is completely dissolved visually and the solution becomes transparent.
X: Undissolved residue is visually confirmed at 25 ° C., or the solution becomes cloudy.

(Dispersibility evaluation)
Dispersibility evaluation was performed by substituting carbon black as a model substance for carbon debris, which is an oxidative degradation product produced by oxidation of lubricating oil exposed to high temperatures, and for compounds produced under incomplete combustion of organic matter. A dispersion test sample was prepared by adding 0.1 g of carbon black (acetylene carbon black, manufactured by STREM CHEMICALS), 0.02 g of the polymers of Examples and Comparative Examples, and 20.0 g of base oil to a 50 ml glass bottle. The dispersion sample was stirred at 750 rpm for 4 hours using a stirrer chip, and allowed to stand at room temperature for 7 days. Then, the presence or absence of carbon black sedimentation was visually evaluated based on the following evaluation criteria.
A: No sediment (the solution is uniform and the dispersibility is very good)
◯: Very small amount of sediment (good dispersibility)
Δ: Precipitate present (dispersibility is slightly poor)
X: There are many sediments (the solution is not uniform or separated, and the dispersibility is poor)

(Comparative Example 1)
In a reaction vessel equipped with a stirrer, temperature sensor, cooling pipe, nitrogen introduction pipe, and dropping funnel, 20 parts of methyl methacrylate (MMA), 30 parts of stearyl methacrylate (SMA), 46.7 parts of toluene, antioxidant (ADK STAB) 2112 (manufactured by ADEKA) and 0.75 part of n-dodecyl mercaptan (DM) were charged, and the content was heated to 85 ° C. while introducing nitrogen gas. As a polymerization initiator, 0.25 part of 2,2-azobis (2,4-dimethylvaleronitrile) (V-65, manufactured by Wako Pure Chemical Industries, Ltd.) and 2.25 parts of toluene were added and a polymerization initiator was added. Solution polymerization was allowed to proceed while dropwise adding a mixed solution of 0.25 parts of initiator, 0.75 parts of DM, 20 parts of MMA, 30 parts of SMA, and 50 parts of toluene over 4 hours, followed by further aging for 2 hours.

  After aging, 0.3 part of the polymerization initiator dissolved in 2.3 parts of toluene was added to the reaction vessel, and further reacted for 3 hours.

The obtained polymerization liquid was heated at 150 ° C. for 1 hour under vacuum to remove the toluene, thereby obtaining a polymer 1.
Example 1
Comparative Example 1 except that 20 parts of MMA in the initial charge were changed to 17.5 parts of MMA and 2.5 parts of N-phenylmaleimide (PMI), and 20 parts of dropped MMA were changed to 17.5 parts of MMA and 2.5 parts of PMI. Thus, the polymer 2 was obtained.
(Example 2)
A polymer 3 was obtained in the same manner as in Comparative Example 1 except that 20 parts of MMA in the initial charge were changed to 10 parts of MMA and 10 parts of PMI, and 20 parts of dropped MMA were changed to 10 parts of MMA and 10 parts of PMI.
(Example 3)
A polymer 4 was obtained in the same manner as in Example 1 except that PMI was changed to benzylmaleimide (BzMI).
The evaluation results using the obtained polymer are shown in Table 1.

  FIG. 1 shows the dispersibility. Although it separated in (a) which shows the dispersibility in the comparative example 1, it has confirmed that it disperse | distributing without isolate | separating in (b) which shows the dispersibility in Example 2. FIG.

  By using a polymer obtained by polymerizing a maleimide monomer as an essential component, an ashless detergent / dispersant with good dispersibility having both heat resistance and base oil solubility was obtained. In particular, the use of N-phenylmaleimide has confirmed that the effect appears more remarkably.

  The lubricating oil composition using the ashless detergent / dispersant containing the polymer of the present invention can improve heat resistance and dispersion performance in a high-temperature environment as compared with the conventional lubricating oil composition, and a smaller amount. Since the effect is exhibited by the addition amount, it can be suitably used for drive system lubricant oil, hydraulic oil, and engine oil while maintaining sufficient solubility in the lubricant base oil and easy handling.

Claims (5)

The monomer component is a polymer obtained by polymerizing (a) a maleimide monomer represented by the following general formula (1) (hereinafter referred to as “component (a)”) as an essential component, An ashless detergent / dispersant having a combined weight average molecular weight (Mw) of 200,000 or less.

Wherein R ¹ and R ² are each independently a hydrogen atom or an alkyl group, and X is a hydrogen atom, a linear, cyclic or branched alkyl group (including an alkyl group having an aromatic ring) or aryl Group.) In addition to the component (a), the polymer comprises (b) an alkyl (meth) acrylate having an aliphatic hydrocarbon group having 6 to 40 carbon atoms (hereinafter referred to as “component (b)”), and (c) 2. The polymer obtained by polymerizing an alkyl (meth) acrylate having an aliphatic hydrocarbon group having 1 to 5 carbon atoms (hereinafter referred to as “component (c)”) as an essential component. Ashless detergent. The ashless detergent / dispersant according to claim 1 or 2, wherein the unit derived from the component (a) is 5 to 50 parts by mass with respect to 100 parts by mass of the polymer. The ashless detergent-dispersant in any one of Claims 1-3 whose unit derived from (b) component is 50 mass parts or more and less than 95 mass parts with respect to 100 mass parts of this polymer.   A lubricating oil composition comprising a lubricating base oil and the ashless detergent-dispersant according to any one of claims 1 to 4.

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