JP5953995B2 - Automotive lubricant - Google Patents

Description

  The present invention relates to a lubricating oil for automobiles.

  In recent years, there has been a strong demand for improvement in the performance of lubricating oil in devices and machines used in various industrial fields such as automobiles, home appliances, electronic information devices, and industrial machines. That is, with the increase in speed, efficiency, and downsizing of equipment, the use conditions in applications such as engine oil, transmission oil, metalworking oil, hydraulic fluid, grease, etc. have become increasingly severe, There is a need for lubricating oils that have higher performance than oils.

  Conventionally, inexpensive and easily available mineral oils have been used as lubricating oils or lubricating base oils. Mineral oil is a mixture of hydrocarbon oils with various chemical structures, and is roughly divided into paraffinic and naphthenic (cycloparaffinic) based on the chemical structure of the main hydrocarbon ("Tribology Handbook (Yokendo)" ). Paraffinic mineral oils and naphthenic mineral oils differ in viscosity characteristics, lubrication characteristics, and low-temperature flow characteristics, and also differ in heat resistance characteristics and compatibility characteristics with lubricating oil additives depending on the degree of purification. When used as a lubricating base oil, it is used properly depending on the intended use.

In recent years, as the required characteristics such as use under high load conditions and maintenance-free conditions have become stricter, it has become extremely difficult to satisfy the required characteristics by using a general-purpose mineral oil as a lubricating oil or base oil. For example, a base oil that has low viscosity resistance at low temperatures and excellent oil film retention at high temperatures (that is, a high viscosity index base oil) is essential for the demand for high fuel efficiency in automotive engine oils (monthly publication) "Lubrication Economy", edited by Lubricating News Agency, February 2010).
Examples of the high-viscosity index base oil include wax isomerized base oil (mineral oil obtained by isomerization of wax content), GTL (Gas To Liquid) base oil, and synthetic base oil PAO (Poly-α-olefin). Etc. are known. These high viscosity index base oils are rarely used alone, and are usually used as lubricating oils only after blending various base oils and lubricating oil additives in order to exhibit desired properties.

  However, these base oils are relatively incompatible with various base oils and lubricating oil additives as compared with general-purpose mineral oils, so compatibilizing relatively polar compounds such as ether compounds and ester compounds. It mix | blends as an agent (patent documents 1-2). On the other hand, a compound having relatively polarity exhibits a problem that it exhibits aggressiveness to organic materials because of its polarity (for example, in the case of automobile engine oil, a rubber material used for a sealing member swells significantly). (Patent document 3), and there is an economic weakness that it is more expensive than general-purpose mineral oil.

JP 2007-39480 A JP 2010-59374 A International Publication WO2004 / 058928 Pamphlet

  An object of this invention is to provide the lubricating oil for motor vehicles and the lubricating oil additive for motor vehicles.

The inventors of the present invention have studied a lubricating oil for automobiles having a high required performance hurdle, and firstly obtained the following knowledge (1). Examples of important performance requirements include viscosity characteristics, lubrication characteristics, flash point, low temperature characteristics, thermal oxidation stability, high temperature cleanability, water resistance, material compatibility, and low temperature storage stability.
(1) Although the performance of a lubricating oil blended with an ether compound or an ester compound that has been conventionally known as an automotive lubricating oil additive was confirmed, it was recognized that the viscosity characteristics and the lubricating characteristics were at satisfactory levels, It turned out that it cannot be said that it has reached the level which can fully satisfy all the required performances.

Next, the inventors proceeded with investigation focusing on heat-resistant oxidation stability, high-temperature cleanability, water resistance, material compatibility, low-temperature characteristics, low-temperature storage stability, and flash point, and the following (2) to ( The knowledge of 4) was obtained.
(2) In automotive lubricating oils based on hydrocarbon-based lubricating oils, by incorporating alicyclic dicarboxylic acid diesters with specific structures as modifiers (lubricating oil additives), heat-resistant oxidation stability, high-temperature cleaning It was found that the balance of the property, water resistance and material compatibility was good, and the low-temperature storage stability was also good, and it was useful as a lubricating oil for automobiles.
(3) The alicyclic dicarboxylic acid diester having a specific structure can be blended in a relatively small amount as compared with the conventional lubricant additives for automobiles such as aliphatic dibasic acid diesters and hindered polyol esters. It should be possible to demonstrate good performance. In other words, the alicyclic dicarboxylic acid diester of the specific structure means that it is a high-performance automotive lubricant additive.
(4) An automotive lubricating oil composition in which an alicyclic dicarboxylic acid diester having a specific structure as an automotive lubricating oil additive is blended in a specific content range with respect to a hydrocarbon-based lubricating oil has the required performance. Being able to demonstrate more effectively.
The present invention has been completed based on this finding.

  That is, this invention provides the lubricating oil composition for motor vehicles and the lubricating oil additive for motor vehicles of the following items.

［式中、Ｒ^１及びＲ^２は、同一又は異なって、それぞれ、炭素数４〜１２の直鎖状若しくは分岐鎖状アルキル基を表す。またＡは、シクロヘキサン環又はシクロヘキセン環を表し、Ｘは水素原子又はメチル基を表す。］
で表される脂環式ジカルボン酸ジエステル２種以上を含有し、かつ、その２種以上の脂環式ジカルボン酸ジエステルにはＲ^１及びＲ^２の少なくとも何れか一方がｎ−ノニル基で表される脂環式ジカルボン酸ジエステルが含まれ、
脂環式ジカルボン酸ジエステルの総含有量が炭化水素系基油１００重量部に対して０．５〜２０重量部の範囲である、自動車用潤滑油組成物。
（項２） Ｒ^１及びＲ^２の少なくとも何れか一方がｎ−ノニル基で表される脂環式ジカルボン酸ジエステルの含有割合が、２種以上の脂環式ジカルボン酸ジエステルの総量に対して５０％以上である、上記項１に記載の自動車用潤滑油組成物。
（項３） ２種以上の脂環式ジカルボン酸ジエステルに一般式（１）におけるＲ^１及びＲ^２の少なくとも何れか一方が炭素数９の分岐鎖状アルキル基で表される脂環式ジカルボン酸ジエステルが含まれる、上記項１又は項２に記載の自動車用潤滑油組成物。
（項４） 一般式（１）におけるＡに対する２つのアルキルオキシカルボニル基（−ＣＯＯＲ^１及び−ＣＯＯＲ^２）の置換位置が隣接する位置である、上記項１〜３の何れかに記載の自動車用潤滑油組成物。
（項５） ２種以上の脂環式ジカルボン酸ジエステル（混合物）が粘度指数９０〜１３０を有するものである、上記項１〜４の何れかに記載の自動車用潤滑油組成物。
（項６） 炭化水素系基油が粘度指数８０〜１６０を有するものである、上記項１〜５の何れかに記載の自動車用潤滑油組成物。
（項７） 自動車用潤滑油組成物の引火点が２００℃以上であり、かつ１００℃における動粘度が１．５〜４０ｍｍ２／ｓである、上記項１〜６の何れかに記載の自動車用潤滑油組成物。
（項８） 自動車用潤滑油組成物が、エンジン用、変速機用又はショックアブソーバー用潤滑油組成物である、上記項１〜７の何れかに記載の自動車用潤滑油組成物。
（項９）一般式（１）

［式中、Ｒ^１及びＲ^２は、同一又は異なって、それぞれ、炭素数４〜１２の直鎖状若しくは分岐鎖状アルキル基を表す。またＡは、シクロヘキサン環又はシクロヘキセン環を表し、Ｘは水素原子又はメチル基を表す。］
で表される脂環式ジカルボン酸ジエステル２種以上からなり、かつ、その２種以上の脂環式ジカルボン酸ジエステルにはＲ^１及びＲ^２の少なくとも何れか一方がｎ−ノニル基で表される脂環式ジカルボン酸ジエステルが含まれる、自動車用潤滑油添加剤。
（項１０） Ｒ^１及びＲ^２の少なくとも何れか一方がｎ−ノニル基で表される脂環式ジカルボン酸ジエステルの含有割合が、２種以上の脂環式ジカルボン酸ジエステルの総量に対して５０％以上である、上記項９に記載の自動車用潤滑油添加剤。
（項１１） ２種以上の脂環式ジカルボン酸ジエステルに一般式（１）におけるＲ^１及びＲ^２の少なくとも何れか一方が炭素数９の分岐鎖状アルキル基で表される脂環式ジカルボン酸ジエステルが含まれる、上記項９又は項１０に記載の自動車用潤滑油添加剤。
（項１２） 一般式（１）におけるＡに対する２つのアルキルオキシカルボニル基（−ＣＯＯＲ^１及び−ＣＯＯＲ^２）の置換位置が隣接する位置である、上記項９〜１１の何れかに記載の自動車用潤滑油添加剤。
（項１３） 炭化水素系基油、及び
一般式（２）

［式中、Ａはシクロヘキサン環又はシクロヘキセン環を表し、Ｘは水素原子又はメチル基を表す。］
で表される脂環式ジカルボン酸と、ｎ−ノナノールと、炭素数４〜１２の直鎖状又は分岐鎖状脂肪族飽和アルコール（ただしｎ−ノナノールを除く。）とをエステル化反応して得られる脂環式ジカルボン酸ジエステルを含有し、該脂環式ジカルボン酸ジエステルの含有量が炭化水素系基油１００重量部に対して０．５〜２０重量部の範囲である、自動車用潤滑油組成物。
（項１４） ｎ−ノナノールと炭素数４〜１２の直鎖状又は分岐鎖状脂肪族飽和アルコール（ただしｎ−ノナノールを除く。）との割合（モル比）が、９５：５〜５０：５０の範囲である、上記項１３に記載の自動車用潤滑油組成物。
（項１５） 炭素数４〜１２の直鎖状又は分岐鎖状脂肪族飽和アルコールに炭素数９の分岐鎖状脂肪族飽和アルコールが必須成分として含まれる、上記項１３又は項１４に記載の自動車用潤滑油組成物。
（項１６） 一般式（２）におけるＡに対する２つのカルボキシル基の置換位置が隣接する位置である、上記項１３〜１５の何れかに記載の自動車用潤滑油組成物。
（項１７）
脂環式ジカルボン酸ジエステルが粘度指数９０〜１３０を有するものである、上記項１３〜１６の何れかに記載の自動車用潤滑油組成物。
（項１８） 炭化水素系基油が粘度指数８０〜１６０を有するものである、上記項１３〜１７の何れかに記載の自動車用潤滑油組成物。
（項１９） 自動車用潤滑油組成物の引火点が２００℃以上であり、かつ１００℃における動粘度が１．５〜４０ｍｍ２／ｓである、上記項１３〜１８の何れかに記載の自動車用潤滑油組成物。
（項２０） 自動車用潤滑油組成物が、エンジン用、変速機用又はショックアブソーバー用潤滑油組成物である、上記項１３〜１９の何れかに記載の自動車用潤滑油組成物。
（項２１）
一般式（２）

［式中、Ａはシクロヘキサン環又はシクロヘキセン環を表し、Ｘは水素原子又はメチル基を表す。］
で表される脂環式ジカルボン酸と、ｎ−ノナノールと、炭素数４〜１２の直鎖状又は分岐鎖状脂肪族飽和アルコール（ただしｎ−ノナノールを除く。）とをエステル化反応して得られる脂環式ジカルボン酸ジエステルからなる自動車用潤滑油添加剤。
（項２２） ｎ−ノナノールと炭素数４〜１２の直鎖状又は分岐鎖状脂肪族飽和アルコール（ただしｎ−ノナノールを除く。）との割合（モル比）が、９５：５〜５０：５０の範囲である、上記項２１に記載の自動車用潤滑油添加剤。
（項２３） 炭素数４〜１２の直鎖状又は分岐鎖状脂肪族飽和アルコールに炭素数９の分岐鎖状脂肪族飽和アルコールが必須成分として含まれる、上記項２１又は項２２に記載の自動車用潤滑油添加剤。
（項２４） 一般式（２）におけるＡに対する２つのカルボキシル基の置換位置が隣接する位置である、上記項２１〜２３の何れかに記載の自動車用潤滑油添加剤。 (Claim 1) Hydrocarbon base oil and general formula (1)

[Wherein, R ¹ and R ² are the same or different and each represents a linear or branched alkyl group having 4 to 12 carbon atoms. A represents a cyclohexane ring or a cyclohexene ring, and X represents a hydrogen atom or a methyl group. ]
And at least ^one of R ¹ and R ² is represented by an n-nonyl group in the two or more alicyclic dicarboxylic acid diesters. Alicyclic dicarboxylic acid diesters,
A lubricating oil composition for automobiles, wherein the total content of the alicyclic dicarboxylic acid diester is in the range of 0.5 to 20 parts by weight with respect to 100 parts by weight of the hydrocarbon base oil.
(Item 2) The content ratio of the alicyclic dicarboxylic acid diester in which at least ^one of R ¹ and R ² is represented by an n-nonyl group is 50 with respect to the total amount of two or more alicyclic dicarboxylic acid diesters. The lubricating oil composition for automobiles according to Item 1, which is at least%.
(Item 3) An alicyclic dicarboxylic acid in which at least ^one of R ¹ and R ² in the general formula (1) is represented by a branched alkyl group having 9 carbon atoms in two or more types of alicyclic dicarboxylic acid diesters. Item 3. The automotive lubricating oil composition according to Item 1 or 2, wherein a diester is contained.
(Item 4) The vehicle according to any one of Items 1 to 3, wherein the substitution positions of the ^two alkyloxycarbonyl groups (—COOR ¹ and —COOR ² ) for A in Formula (1) are adjacent positions. Lubricating oil composition.
(Item 5) The automotive lubricating oil composition according to any one of Items 1 to 4, wherein two or more alicyclic dicarboxylic acid diesters (mixtures) have a viscosity index of 90 to 130.
(Item 6) The automotive lubricating oil composition according to any one of Items 1 to 5, wherein the hydrocarbon base oil has a viscosity index of 80 to 160.
(Item 7) The automotive lubricating oil composition according to any one of Items 1 to 6, wherein the flash point of the automotive lubricating oil composition is 200 ° C or higher, and the kinematic viscosity at 100 ° C is 1.5 to 40 mm2 / s. Lubricating oil composition.
(Item 8) The vehicle lubricant composition according to any one of Items 1 to 7, wherein the vehicle lubricant composition is an engine, transmission, or shock absorber lubricant composition.
(Item 9) General formula (1)

[Wherein, R ¹ and R ² are the same or different and each represents a linear or branched alkyl group having 4 to 12 carbon atoms. A represents a cyclohexane ring or a cyclohexene ring, and X represents a hydrogen atom or a methyl group. ]
And at least ^one of R ¹ and R ² is represented by an n-nonyl group in the two or more alicyclic dicarboxylic acid diesters. A lubricating oil additive for automobiles containing an alicyclic dicarboxylic acid diester.
(Item 10) The content ratio of the alicyclic dicarboxylic acid diester in which at least ^one of R ¹ and R ² is represented by an n-nonyl group is 50 with respect to the total amount of two or more alicyclic dicarboxylic acid diesters. Item 10. The lubricating oil additive for automobiles according to Item 9, which is at least%.
(Item 11) An alicyclic dicarboxylic acid in which at least ^one of R ¹ and R ² in the general formula (1) is represented by a branched alkyl group having 9 carbon atoms in two or more types of alicyclic dicarboxylic acid diesters Item 11. The automobile lubricant additive according to Item 9 or 10, wherein a diester is contained.
(Item 12) The vehicle-use product according to any one of Items 9 to 11, wherein the substitution positions of the ^two alkyloxycarbonyl groups (—COOR ¹ and —COOR ² ) for A in Formula (1) are adjacent positions. Lubricating oil additive.
(Claim 13) Hydrocarbon base oil and general formula (2)

[Wherein, A represents a cyclohexane ring or a cyclohexene ring, and X represents a hydrogen atom or a methyl group. ]
It is obtained by esterifying the alicyclic dicarboxylic acid represented by the formula: n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol). And a lubricating oil composition for automobiles, wherein the alicyclic dicarboxylic acid diester is contained in a range of 0.5 to 20 parts by weight with respect to 100 parts by weight of the hydrocarbon base oil. object.
(Item 14) The ratio (molar ratio) between n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol) is from 95: 5 to 50:50. Item 14. The automotive lubricating oil composition according to Item 13, wherein the lubricating oil composition is for automobiles.
(Item 15) The automobile according to Item 13 or Item 14, wherein the C4-C12 linear or branched aliphatic saturated alcohol contains a C9 branched aliphatic saturated alcohol as an essential component. Lubricating oil composition.
(Item 16) The automobile lubricating oil composition according to any one of Items 13 to 15, wherein the substitution positions of the two carboxyl groups for A in Formula (2) are adjacent positions.
(Section 17)
Item 17. The automotive lubricating oil composition according to any one of Items 13 to 16, wherein the alicyclic dicarboxylic acid diester has a viscosity index of 90 to 130.
(Item 18) The lubricating oil composition for an automobile according to any one of Items 13 to 17, wherein the hydrocarbon base oil has a viscosity index of 80 to 160.
(Item 19) The automotive lubricating oil composition according to any one of Items 13 to 18, wherein the flash point of the automotive lubricating oil composition is 200 ° C or higher and the kinematic viscosity at 100 ° C is 1.5 to 40 mm2 / s. Lubricating oil composition.
(Item 20) The vehicle lubricant composition according to any one of Items 13 to 19, wherein the vehicle lubricant composition is an engine, transmission, or shock absorber lubricant composition.
(Item 21)
General formula (2)

[Wherein, A represents a cyclohexane ring or a cyclohexene ring, and X represents a hydrogen atom or a methyl group. ]
It is obtained by esterifying the alicyclic dicarboxylic acid represented by the formula: n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol). Lubricating oil additive for automobiles comprising the produced alicyclic dicarboxylic acid diester.
(Item 22) The ratio (molar ratio) between n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol) is from 95: 5 to 50:50. Item 22. The automotive lubricant additive according to Item 21, which is in the range of
(Item 23) The automobile according to Item 21 or Item 22, wherein the C4-C12 linear or branched aliphatic saturated alcohol contains a C9 branched aliphatic saturated alcohol as an essential component. Lubricating oil additive.
(Item 24) The automotive lubricant additive according to any one of Items 21 to 23, wherein the substitution positions of the two carboxyl groups for A in Formula (2) are adjacent to each other.

  According to the present invention, among the required performances required for automotive lubricating oil, the automotive lubricating oil has a good balance of thermal oxidation stability, high temperature cleanliness, water resistance and material compatibility, and good low temperature storage stability. A composition can be obtained. In addition, an automotive lubricating oil additive that improves or improves thermal oxidation stability, high-temperature cleanability, water resistance, and material compatibility can be obtained for automotive lubricating oils containing hydrocarbon base oils.

The automotive lubricating oil composition of the present invention contains a hydrocarbon base oil and two or more alicyclic dicarboxylic acid diesters represented by the general formula (1), and the two or more alicyclic rings. The formula dicarboxylic acid diester includes an alicyclic dicarboxylic acid diester in which at least ^one of R ¹ and R ² in the general formula (1) is represented by an n-nonyl group, and the total content of the alicyclic dicarboxylic acid diester The amount is in the range of 0.5 to 20 parts by weight based on 100 parts by weight of the hydrocarbon base oil, or Alicyclic dicarboxylic acid diester obtained by esterifying n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol). The alicyclic dicarboxylic acid The content of the ester is in the range of 0.5 to 20 parts by weight per 100 parts by weight of oil hydrocarbon radical, it is characterized in.

[Hydrocarbon base oil]
As the hydrocarbon base oil according to the present invention, those generally used as a base oil in the field of automotive lubricating oil can be used, and examples thereof include mineral oil, GTL base oil, and synthetic hydrocarbon base oil. .

  As mineral oil, lubricating oil fraction obtained as distillate by distillation under reduced pressure of atmospheric distillation equipment residue oil of paraffinic, intermediate base or naphthenic crude oil, solvent refining, solvent extraction, hydrocracking, hydrogen Mineral oil consisting of solvent refined oil or hydrotreated oil obtained by arbitrarily selecting one or more purification processes such as hydroisomerization, solvent dewaxing, hydrorefining, and clay treatment, and vacuum distillation residue oil Examples thereof include mineral oil obtained by treating the degreased oil obtained by the solvent debris treatment by the refining step, mineral oil obtained by isomerization of the wax, and mixed oil obtained by mixing these mineral oils. Moreover, highly refined mineral oil is called highly refined base oil, and there is also mineral oil having a very high viscosity index of 140 or more.

  Specific examples of commercially available mineral oil include Super Oil M10, Super Oil M12, Super Oil M22, Super Oil N22, Super Oil M32, Super Oil N32, Super Oil M46, Super Oil N46, Super Oil T46 (Shin Nippon Oil Co., Ltd.) Diana Fresia S10, Diana Fresia S32, Diana Fresia P32, Diana Fresia N28, Diana Fresia U46 (Idemitsu Kosan Co., Ltd.), Process 123 (Showa Shell Sekiyu Co., Ltd.), Celeo 10, Celeo SP10, Celeo NH46, Neutral 150 (manufactured by Japan Energy), Solvent Neutral 60, Solvent Neutral 60LP, Solvent Neutral 100, Solvent Neutral 130, Levent Neutral 100LP, Flexon 848, Tellura 611, Tellura 624, Plastoor 65, Plastoor 155, Plastoru J150, Flexon 642 (manufactured by ExxonMobil), Crisef Oil H22, Crisef Oil F22, Crisef Oil H46, Crisef Oil F46 (New Japan) Petroleum Co., Ltd.), Cosmo Pure Safety 10, Cosmo Pure Safety 10W, Cosmo Pure Spin RC, Cosmo Pure Spin C, Cosmo Pure Spin W, Cosmo Pure Spin TK, Cosmo Neutral 100, Cosmo Neutral 150, Cosmo Pure Spin G, Cosmo Pure Spin 46N, Cosmo Pure Safety 22, Cosmo Pure Safety 32, Cosmo Pure Safety 46 (manufactured by Cosmo Oil Co., Ltd.) There are exemplified. These may be used alone or in combination of two or more.

  Examples of the GTL base oil include a lubricating oil fraction separated from a liquid product obtained by using a natural gas or the like as a raw material by a GTL process, a lubricating oil fraction obtained by hydrocracking a produced wax, and the like.

  Examples of the synthetic hydrocarbon base oil include synthetic hydrocarbon oils such as poly-α-olefin, polybutene, alkylbenzene, and alkylnaphthalene, and isomerized oils of synthetic hydrocarbons obtained by the Fischer-Tropsch method.

Examples of the poly-α-olefin include α-olefins having 2 to 16 carbon atoms (for example, ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene). Etc.) or a copolymer.
Specific examples of commercially available poly-α-olefins (hereinafter referred to as “PAO”) include Lucant ethylene / α-olefin oligomer HC-10 (manufactured by Mitsui Chemicals), Fortum NEXBASE 2002, Fortum NEXBASE 2004, Fortum NEXBASE 2006. , Fortum NEXBASE 2008 (manufactured by Matsuwa Sangyo Co., Ltd.), Durashin 162, Durashin 164, Duracin 166, Durashin 168 (manufactured by BP Japan), Sinfluid 201, Sinfluid 401, Sinfluid 601 and Sinfluid 801 (New) Manufactured by Nippon Steel Chemical Co., Ltd.), SpectraSyn2, SpectraSyn4, SpectraSyn6, SpectraSyn8, SpectraSyn10, PureSyn 2, PureSyn4, PureSyn6, and PureSyn8 (manufactured by Exxon Mobil Corporation), Riporubu 40, Riporubu 60, Riporubu 80, Riporubu 100 (manufactured by Lion Corporation), and the like.

The polybutene is exemplified by a polymer of isobutylene or a copolymer of isobutylene and 1-butylene, and generally has a kinematic viscosity at 100 ° C. in the range of 2 to 6000 mm 2 / s.
Specific examples of commercially available polybutene include Indopole L-2, Indopole L-3, Indopole L-6, Indopole L-8, Indopole L-14 (manufactured by BP Japan Co., Ltd.) Is done.

  Examples of the alkyl benzene include monoalkyl benzene, dialkyl benzene, trialkyl benzene, and tetraalkyl benzene having a molecular weight of 200 to 450, which are substituted with a linear or branched alkyl group having 1 to 40 carbon atoms.

  Examples of the alkylnaphthalene include monoalkylnaphthalene and dialkylnaphthalene having a molecular weight of 200 to 450 and substituted with a linear or branched alkyl group having 1 to 30 carbon atoms.

Among the hydrocarbon base oils, a synthetic hydrocarbon base oil is preferable because it is stable in quality and easily exhibits the effects of the present invention. Among the synthetic hydrocarbon base oils, poly-α-olefins are particularly preferable because they are excellent in heat resistance and have a high viscosity index.
The hydrocarbon base oil can be used singly or in combination of two or more kinds including the above examples, and it is recommended that a synthetic hydrocarbon base oil is used as a main component. The main component means that the synthetic hydrocarbon base oil is contained in 50 parts by weight or more, preferably 70 parts by weight or more in 100 parts by weight of the hydrocarbon base oil.

  As an indicator of the hydrocarbon base oil according to the present invention, the viscosity index of the base oil itself is one of the important factors from the viewpoint of the effect on the viscosity characteristics of the automotive lubricating oil composition of the present invention. Kinematic viscosity at ° C is important. It should be noted that it is recommended to select as appropriate in applications that lead to further details of automobile applications.

The viscosity index of the hydrocarbon base oil according to the present invention is preferably 80 to 160, more preferably 100 to 160. By adopting the hydrocarbon base oil within these ranges, the superiority of the viscosity characteristics of the automotive lubricating oil composition is recognized.
The kinematic viscosity at 100 ° C. of the hydrocarbon base oil according to the present invention is preferably 1.5 to 40 mm 2 / s, more preferably 2.5 to 30 mm 2 / s. By adopting the hydrocarbon base oil within these ranges, the superiority of the viscosity characteristics of the automotive lubricating oil composition is recognized.

  In the relationship between the kinematic viscosity at 100 ° C. and the viscosity index of the hydrocarbon base oil according to the present invention, a hydrocarbon base oil having a kinematic viscosity at 100 ° C. of 1.5 to 40 mm 2 / s and a viscosity index of 80 to 160 is obtained. More preferred is a hydrocarbon base oil having a kinematic viscosity at 100 ° C. of 2.5 to 30 mm 2 / s and a viscosity index of 100 to 160.

[Alicyclic dicarboxylic acid diester]
The alicyclic dicarboxylic acid diester used in the automotive lubricating oil composition of the present invention contains two or more alicyclic dicarboxylic acid diesters represented by the above general formula (1), and the two or more types thereof. A mixture containing an alicyclic dicarboxylic acid diester in which at least ^one of R ¹ and R ² in the general formula (1) is represented by an n-nonyl group, or the above general formula (2) It is obtained by esterifying the alicyclic dicarboxylic acid represented by the formula: n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol). Diester compound (mixture).
In addition, since the alicyclic dicarboxylic acid diester according to the present invention is a mixture, the configuration with the “esterified alicyclic dicarboxylic acid diester obtained by the esterification reaction” is adopted as a simple and clearly defined method. It does not mean an ester compound obtained by limiting to a specific production method. Although the manufacturing method of the said alicyclic dicarboxylic acid diester is also mentioned later, in addition to esterification reaction (direct dehydration condensation reaction), the alicyclic dicarboxylic acid anhydride represented by the general formula (2) Or a production method for carrying out an esterification reaction using a chloride as a starting material, a production method for carrying out an ester exchange reaction using an ester or an aryl ester of the alicyclic dicarboxylic acid and a lower alcohol (1 to 3 carbon atoms), , After esterifying a specific aromatic dicarboxylic acid component (phthalic acid, isophthalic acid, terephthalic acid, methyl-substituted phthalic acid, methyl-substituted isophthalic acid, methyl-substituted terephthalic acid) with a predetermined aliphatic saturated alcohol It is also possible to employ a method of producing by nuclear hydrogenation.

The content ratio of the alicyclic dicarboxylic acid diester in which at least ^one of R ¹ and R ² in the general formula (1) is represented by an n-nonyl group is based on the total amount of two or more alicyclic dicarboxylic acid diesters. Thus, 50% or more, more preferably 50 to 95%, particularly 70 to 95% is recommended.
Moreover, the alicyclic dicarboxylic acid represented by the general formula (2), n-nonanol, and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol). In the esterification reaction, the ratio (molar ratio) between n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol) is preferably 95. : 5-50: 50, more preferably in the range of 95: 5-70: 30 is recommended.

In the general formula (1) or the general formula (2) constituting a part of the chemical structure of the alicyclic dicarboxylic acid diester according to the present invention, the site of “XA =” is specifically cyclohexanedicarboxylic acid or cyclohexene. It is expressed as a residue obtained by removing all carboxyl groups from dicarboxylic acid, methylcyclohexanedicarboxylic acid or methylcyclohexenedicarboxylic acid.
In addition, the substitution positions of two alkyloxycarbonyl groups (that is, —COOR ¹ , —COOR ² : alkyl ester group) or two carboxyl groups with respect to A are 1,2-position, 1,3-position and 1, There is a 4-position (ie, it is not substituted for the same carbon), preferably the 1,2-position (adjacent position) is recommended. By adopting the 1,2-position (adjacent position) as the substitution position, a tendency to further improve the hydrolysis resistance of the alicyclic dicarboxylic acid diester itself is recognized. It also has a positive effect on improving the water resistance of the oil composition.
Moreover, when X is a methyl group, the substitution position of the methyl group does not exist in carbon substituted by two alkyloxycarbonyl groups.

Specific examples of the cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, methylcyclohexanedicarboxylic acid, and methylcyclohexenedicarboxylic acid include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. Cyclohexene dicarboxylic acids such as 4-cyclohexene-1,2-dicarboxylic acid and 1-cyclohexene-1,2-dicarboxylic acid; 3-methylcyclohexane-1,2-dicarboxylic acid, 4-methylcyclohexane-1 Methylcyclohexanedicarboxylic acid such as 1,2-dicarboxylic acid; methylcyclohexenediyl such as 3-methyl-4-cyclohexene-1,2-dicarboxylic acid, 4-methyl-4-cyclohexene-1,2-dicarboxylic acid Carboxylic acid.
Among these, 1,2-cyclohexanedicarboxylic acid, 3-methyl-1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, 3-methyl -4-cyclohexene-1,2-dicarboxylic acid, 4-methyl-4-cyclohexene-1,2-dicarboxylic acid are preferred, especially 1,2-cyclohexanedicarboxylic acid, 3-methyl-1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid is preferred.
In addition, description of the said specific example is synonymous with the specific example of the alicyclic dicarboxylic acid represented by the said General formula (2).

R1 and R2 in the general formula (1) are the same or different and each is a linear or branched alkyl group having 4 to 12 carbon atoms, preferably a linear or branched group having 7 to 11 carbon atoms. A chain alkyl group, particularly an n-nonyl group or a branched chain alkyl group having 9 carbon atoms, is recommended.

As the alkyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group Linear alkyl group, 2-methyl-1-propyl group, 2-butyl group, 2-methyl-2-propyl group having 4 carbon atoms; 3-methyl-1-butyl group, 2- Pentanol, 3-pentyl group, 2-methyl-1-butyl group, 2-methyl-2-butyl group, 3-methyl-2-butyl group, 2,2-dimethyl-1-propyl group having 5 carbon atoms Branched alkyl group; branched chain having 6 carbon atoms such as 4-methyl-1-pentyl group, 2-hexyl group, 3-hexyl group, 2-methyl-1-pentyl group, 2-ethyl-1-butyl group Alkyl group; 5-methyl-1-hexyl group, 2-hexyl C7 branched alkyl groups such as til, 3-heptyl, 4-heptyl, 2-methyl-1-hexyl, 2-methyl-3-hexyl, 2-ethyl-1-pentyl A branched alkyl group having 8 carbon atoms such as 6-methyl-1-heptyl group, 2-octyl group, 3-octyl group, 2-methyl-1-heptyl group, 2-ethyl-1-hexyl group; 7 -Methyl-1-octyl group, 2-nonyl group, 3-nonyl group, 2-methyl-1-octyl group, 3-methyl-1-octyl group, 4-methyl-1-octyl group, 5-methyl-1 -Octyl group, 6-methyl-1-octyl group, 2-ethyl-1-heptyl group, 2,4-dimethyl-1-heptyl group, 2,5-dimethyl-1-heptyl group, 4,6-dimethyl- 1-heptyl group, 2,6-dimethyl-4-heptyl group, , 5,5-trimethyl-1-hexyl group, 2,5,5-trimethyl-1-hexyl group and the like, a branched alkyl group having 9 carbon atoms; 8-methyl-1-nonyl group, 2-decyl group, 3-decyl group, 2-methyl-1-nonyl group, 2-ethyl-1-octyl group, 2-propyl-1-heptyl group, 2,7-dimethyl-1-octyl group, 2,6-dimethyl-2 -Octyl group, 2,4-dimethyl-1-octyl group, 3,7-dimethyl-1-octyl group, 3,6-dimethyl-3-octyl group, 4-methyl-2-propyl-1-hexyl group, 5-methyl-2-propyl-1-hexyl group, 2- (1-methylethyl) -4-methyl-1-hexyl group, 2- (1-methylethyl) -5-methyl-1-hexyl group, etc. Examples thereof include a branched alkyl group having 10 carbon atoms.

The monoalcohol used for obtaining the alicyclic dicarboxylic acid diester according to the present invention is n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol). The linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms is preferably a linear or branched aliphatic saturated alcohol having 7 to 11 carbon atoms, more preferably 9 carbon atoms. An embodiment in which a branched aliphatic saturated alcohol is included as an essential component is recommended.

Specific examples of the linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol) include n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-decanol, n-undecanol, n-dodecanol linear aliphatic saturated alcohol, 2-methyl-1-propanol, 2-butanol, 2-methyl-2-propanol branched chain of 4 carbon atoms A saturated aliphatic alcohol; 3-methyl-1-butanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 2, 5-dimethyl branched aliphatic saturated alcohol of 2-dimethyl-1-propanol; 4-methyl-1-pentanol, 2-hexanol, -C6-C6 branched aliphatic saturated alcohols such as hexanol, 2-methyl-1-pentanol, 2-ethyl-1-butanol; 5-methyl-1-hexanol, 2-heptanol, 3-heptanol, 4 -C7 branched aliphatic saturated alcohols such as heptanol, 2-methyl-1-hexanol, 2-methyl-3-hexanol, 2-ethyl-1-pentanol; 6-methyl-1-heptanol, 2 -C8 branched aliphatic saturated alcohols such as octanol, 3-octanol, 2-methyl-1-heptanol, 2-ethyl-1-hexanol; 7-methyl-1-octanol, 2-nonanol, 3- Nonanol, 2-methyl-1-octanol, 3-methyl-1-octanol, 4-methyl-1-octanol, 5-methyl- -Octanol, 6-methyl-1-octanol, 2-ethyl-1-heptanol, 2,4-dimethyl-1-heptanol, 2,5-dimethyl-1-heptanol, 4,6-dimethyl-1-heptanol, 2 Branched aliphatic saturated alcohols having 9 carbon atoms such as 1,6-dimethyl-4-heptanol, 3,5,5-trimethyl-1-hexanol, 2,5,5-trimethyl-1-hexanol; 1-nonanol, 2-decanol, 3-decanol, 2-methyl-1-nonanol, 2-ethyl-1-octanol, 2-propyl-1-heptanol, 2,7-dimethyl-1-octanol, 2,6- Dimethyl-2-octanol, 2,4-dimethyl-1-octanol, 3,7-dimethyl-1-octanol, 3,6-dimethyl-3-oct Tanol, 4-methyl-2-propyl-1-hexanol, 5-methyl-2-propyl-1-hexanol, 2- (1-methylethyl) -4-methyl-1-hexanol, 2- (1-methylethyl) And C10 branched aliphatic saturated alcohols such as -5-methyl-1-hexanol.

As the aliphatic saturated alcohol, commercially available products, reagents, those prepared by known synthesis methods, and the like can be used.
For example, as a known synthesis method of a linear aliphatic saturated alcohol, a method of producing a fatty acid (or methyl ester) by hydrogen reduction, or a hydroformylation reaction from an α-olefin, carbon monoxide and hydrogen to form an aldehyde And a method in which the aldehyde is hydrogenated and reduced to an alcohol.
Examples of commercially available products include “Conol 10WS” and “Conol 1098” (product name, manufactured by Shin Nippon Rika Co., Ltd.). Also, a mixture such as “lineball 9” (product name, manufactured by Shell Chemicals, composition: a mixture of 70% or more of n-nonanol and 30% or less of 2-methyl-1-octanol), which is mainly composed of n-nonanol. Alcohol is a commercially available product that can be directly used in the esterification reaction according to the present invention.
Known synthetic methods for branched aliphatic saturated alcohols include, for example, a method in which propylene is hydroformylated to form butyraldehyde and hydrogenated after the aldol condensation reaction to prepare 2-ethylhexanol, or isobutylene is a dimer. Hydroformylation of diisobutylene obtained by hydrogenation (dimerization reaction) followed by hydrogenation to prepare 3,5,5-trimethyl-1-hexanol, and hydroformylation obtained by trimerization of propylene (Oxo method) followed by hydrogenation to prepare a branched decanol (wherein the decanol is a mixture of a plurality of isomers having methyl branches, including 8-methyl-1-nonanol, In the case of such a mixture, it is called “isodecanol” and represents a branched saturated aliphatic alcohol. That.), And the like.
In other words, starting from lower olefins such as propylene, n-butylene and isobutylene, dimerization reaction, trimerization reaction, hydroformylation reaction (oxo method), aldol condensation reaction, hydrogenation reaction (reduction of olefin, aldehyde group, etc.) ) And the like, as appropriate, to prepare a branched saturated aliphatic alcohol having a relatively large total carbon number (for example, 8 or more carbon atoms). Depending on the combination of starting materials and reaction method, it may not be a single compound but a mixture of branched saturated aliphatic monoalcohol isomers having the same carbon number and different branched states, such as “isodecanol”. is there. When the obtained alcohol is a mixture of isomers, the isomers can be obtained by separation using a separation method such as rectification.
Examples of main commercial products include 3-methyl-1-hexanol, 5-methyl-1-hexanol, 3-methyl-1-heptanol, 5-methyl-1-heptanol, 2-ethyl-1-hexanol, “ "Octanol" (product name, manufactured by Kyowa Hakko Chemical Co., Ltd.), 3,5,5-trimethyl-1-hexanol, "Nonanol" (product name, manufactured by Kyowa Hakko Chemical Co., Ltd.), 7-methyl-1-octanol, "Oxocol 900 "Product name, manufactured by Kyowa Hakko Chemical Co., Ltd.", "Diadol 9" (product name, manufactured by Mitsubishi Chemical), "Isononanol" (product name, manufactured by Mitsubishi Chemical), "Exaal 9" (product name, manufactured by Exxon) ), 2-ethyl-1-octanol, 8-methyl-1-nonanol, “decanol” (product name, manufactured by Kyowa Hakko Chemical Co., Ltd.), and the like.
Among commercially available products that are industrially available, there is a mixture of a plurality of isomers having methyl branches. In that case, in the present specification and claims, “iso” is added to express the alcohol. And R1 and R2 in the general formula (1) of the corresponding alcohol are referred to as “isoalkyl group” and represent the alicyclic dicarboxylic acid diester. For example, in the case of the expression “isononanol”, it means a mixture of isomers having a total carbon number of 9 and different branching states (a mixture containing a plurality of isomers having different positions of methyl branches, etc.) and corresponding R1 and R2 in the general formula (1) of the alcohol are represented as “isononyl group”.

  The production method of the alicyclic dicarboxylic acid diester according to the present invention is not particularly limited to the production method as long as the target product is obtained. For example, (i) a predetermined acid component (cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid methylcyclohexanedicarboxylic acid, methylcyclohexenedicarboxylic acid, its anhydride, chloride, etc.) and a predetermined alcohol component (C4-C12 aliphatic saturation) Alcohols and their ester-forming derivatives) according to a conventional method, preferably by an esterification reaction with heating and stirring in the presence of an esterification catalyst or in the absence of a catalyst in an inert gas atmosphere such as nitrogen. A method, (ii) a specific aromatic dicarboxylic acid (orthophthalic acid, isophthalic acid, terephthalic acid, methyl-substituted phthalic acid, etc.) and a predetermined alcohol component (aliphatic saturated alcohol having 4 to 12 carbon atoms, ester-forming derivative thereof) According to conventional methods, preferably in an inert gas atmosphere such as nitrogen (Iii) a predetermined acid component which is an ester-forming derivative (iii) a method in which an esterification reaction is carried out with heating and stirring in the presence or absence of an esterification catalyst and then the esterified product is subjected to nuclear hydrogenation. For example, dimethyl cyclohexanedicarboxylate, dimethyl cyclohexenedicarboxylate, dimethyl methylcyclohexanedicarboxylate, dimethyl methylcyclohexenedicarboxylate, etc.) and predetermined alcohol components (aliphatic saturated alcohol having 4 to 12 carbon atoms, ester-forming derivatives thereof) And (iv) a specific acid component (phthalate) which is an ester-forming derivative, preferably by a transesterification reaction under heating and stirring in the presence of a transesterification catalyst in an inert gas atmosphere such as nitrogen. Dimethyl acid, dimethyl isophthalate, Dimethyl phthalate, methyl-substituted dimethyl phthalate, etc.) and a predetermined alcohol component (aliphatic saturated alcohol having 4 to 12 carbon atoms, ester-forming derivative thereof) according to a conventional method, preferably in an inert gas atmosphere such as nitrogen In the method, a method in which the ester exchange reaction is performed while heating and stirring in the presence of a transesterification catalyst, and then the esterified product is prepared by nuclear hydrogenation is exemplified.

As the acid component, in addition to the alicyclic dicarboxylic acid, as an ester-forming derivative, an alicyclic dicarboxylic acid anhydride or chloride, an ester of an alicyclic dicarboxylic acid and a lower alcohol, an active ester such as an aryl ester, etc. Examples of such aspects are exemplified. In the esterification reaction or transesterification reaction, the alicyclic dicarboxylic acid or the ester-forming derivative may be used alone or in combination of two or more.
These exemplified methods are the same when an aromatic dicarboxylic acid diester is produced using an aromatic dicarboxylic acid as an acid component.

  As the alcohol component, in addition to the aliphatic saturated alcohol, an ester-forming derivative having an ester form of a lower fatty acid and the aliphatic saturated alcohol (for example, acetate ester, propionate ester, etc.) It is also possible to obtain the alicyclic dicarboxylic acid diester according to the present invention by transesterification. In the esterification reaction or transesterification reaction, the aliphatic saturated alcohol and the ester-forming derivative can be used alone or in combination of two or more. The used amount of the alcohol component is, for example, about 1 to 1.5 equivalents, preferably about 1.01 to 1.2 equivalents per 1 equivalent of the acid component.

Examples of the catalyst used in the esterification reaction or transesterification reaction include mineral acids, organic acids, Lewis acids, and alkali metals. More specifically, examples of the mineral acid include sulfuric acid, hydrochloric acid, and phosphoric acid, examples of the organic acid include p-toluenesulfonic acid and methanesulfonic acid, and examples of the Lewis acid include aluminum derivatives, tin derivatives, and titanium. Derivatives, lead derivatives, and zinc derivatives are exemplified. Examples of alkali metals include sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide, and the like, and one or more of these can be used in combination. . Among these, a tin derivative and a titanium derivative are preferable. The amount used is, for example, about 0.05 to 1% by weight with respect to the total weight of the acid component and alcohol component as raw materials.

  The reaction temperature is usually 100 to 240 ° C, preferably 150 to 230 ° C. The reaction time is usually 2 to 30 hours.

  In the esterification reaction, if necessary, water generated as a by-product is removed from the reaction system using a water entraining agent (azeotropic action, entraining action, etc.) such as benzene, toluene, xylene, cyclohexane, alkylcyclohexane. It may be removed.

  Also, when oxygenated organic compounds such as oxides, peroxides, and carbonyl compounds are produced by oxidative degradation of raw materials, produced esters and organic solvents (water entraining agents) during the esterification reaction, the heat resistance, weather resistance, etc. are adversely affected. For this reason, it is desirable to carry out the reaction under normal or reduced pressure in an inert gas atmosphere such as nitrogen gas or in an inert gas stream.

  The following steps are exemplified as the step of post-treating the “esterified crude product” obtained after the reaction. For example, a step of distilling off excess raw materials that can be distilled under reduced pressure or normal pressure, a step of performing washing (neutralization) with an aqueous alkaline solution and washing with water when a carboxylic acid component derived from the raw materials remains, a liquid solution Examples include a step of purification by an extraction operation such as extraction, a step of adsorption treatment with an adsorbent such as activated carbon, activated clay, activated alumina, and the like. It is preferable to combine these steps as appropriate and purify the esterified crude product by post-treatment.

  In the case of performing washing (neutralization) with the alkaline aqueous solution, examples of the washing liquid include alkaline aqueous solutions such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and sodium carbonate. The alkali concentration is not particularly limited, but is preferably about 0.5 to 20% by weight. The amount of the alkaline aqueous solution used is recommended to be equivalent to the total acid value of the esterified crude product after completion of the reaction or an amount that is appropriately excessive. And it is preferable to repeat washing | cleaning operation by water with respect to the washing | cleaning material after alkali washing (neutralization) until the water layer of washing water becomes neutral.

Examples of the adsorbent used for the adsorption purification include activated carbon, activated clay, activated alumina, hydrotalcite, silica gel, silica alumina, zeolite, magnesia, calcia, and diatomaceous earth.

  The alicyclic dicarboxylic acid diester thus obtained may have isomers of a trans isomer and a cis isomer due to the configuration of two ester groups. However, in order to exert the effects of the present invention, the trans isomer, cis isomer and Any of those mixtures can be used.

  The acid value of the alicyclic dicarboxylic acid diester (mixture) is preferably 0.1 mgKOH / g or less, more preferably 0.05 mgKOH / g or less. When the acid value is 0.1 mgKOH / g or less, a tendency of improving the heat resistance of the alicyclic dicarboxylic acid diester itself is recognized, and in such a preferable range, the heat-resistant oxidation stability of the lubricating oil composition for automobiles of the present invention is observed. It also has a positive impact on the improvement. As a method of reducing the acid value, a method of sufficiently advancing the reaction, a method of neutralizing and washing with an alkali component in a post-treatment step (a step of washing with the above alkaline aqueous solution (neutralization) and washing with water) And the like.

  The hydroxyl value of the alicyclic dicarboxylic acid diester (mixture) is preferably 2 mgKOH / g or less, more preferably 1 mgKOH / g or less. When the hydroxyl value is 2 mgKOH / g or less, the hygroscopicity of the alicyclic dicarboxylic acid diester itself is lowered and the heat resistance tends to be further improved. In such a preferable range, the lubricating oil composition for automobiles of the present invention is used. It also has a positive effect on the improvement of water resistance and thermal oxidation stability. As a method of reducing the hydroxyl value, a method of sufficiently advancing the reaction or a method of distilling off a monoalcohol component in a post-treatment step under reduced pressure (the above distillable excess raw materials etc. under reduced pressure or normal pressure) And the like).

  The sulfated ash content of the alicyclic dicarboxylic acid diester (mixture) is preferably 50 ppm or less, more preferably 30 ppm or less. When the sulfated ash content is 50 ppm or less, a tendency of improving the heat resistance of the alicyclic dicarboxylic acid diester itself is recognized. In such a preferable range, the heat-resistant oxidation stability of the automotive lubricating oil composition of the present invention is also improved. Has a positive effect. As a method for reducing sulfated ash content, a method using a low acid content (for example, 50 ppm or less) of an acid component or an alcohol component which is a raw material of an alicyclic dicarboxylic acid diester, or an esterification catalyst or a transesterification catalyst. In the case of containing a metal, examples include a method of removing the catalyst itself or the organometallic compound derived from the catalyst by neutralization, water washing, adsorption treatment, or the like in the post-treatment step.

  The pour point of the alicyclic dicarboxylic acid diester (mixture) is preferably −15 ° C. or lower, more preferably −30 ° C. or lower. In such a preferable range, the low temperature fluidity of the automotive lubricating oil composition of the present invention is also positively affected.

  The viscosity index of the alicyclic dicarboxylic acid diester (mixture) is preferably 90 to 130, more preferably 100 to 130. In such a preferable range, the viscosity index of the automotive lubricating oil composition of the present invention is also positively affected.

  The flash point of the alicyclic dicarboxylic acid diester (mixture) is preferably 200 ° C. or higher. In such a preferable range, the flash point of the automotive lubricating oil composition of the present invention is also positively affected.

As described above, the alicyclic dicarboxylic acid diester used in the automotive lubricating oil composition of the present invention uses two or more types, and at least one of two alkyl ester groups among the two or more types. It is essential to include an alicyclic dicarboxylic acid diester represented by an n-nonyl ester group (that is, an n-nonyloxycarbonyl group).
Examples of the alicyclic dicarboxylic acid diester in which at least one of the two alkyl ester groups is represented by an n-nonyl ester group include, for example, 1,2-cyclohexanedicarboxylic acid di (n-nonyl), 4-cyclohexene. -1,2-dicarboxylic acid di (n-nonyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (n-nonyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (n-nonyl), Mixed ester obtained from 1,2-cyclohexanedicarboxylic acid, n-nonanol and 2-methyl-1-propanol, obtained from 1,2-cyclohexanedicarboxylic acid, n-nonanol and 3-methyl-1-butanol Mixed ester, 1,2-cyclohexanedicarboxylic acid and n-nonanol and 4-methyl-1-pentanol Mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-nonanol and 5-methyl-1-hexanol, 1,2-cyclohexanedicarboxylic acid, n-nonanol and 2-methyl Mixed ester obtained from -1-hexanol, mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-nonanol and 6-methyl-1-heptanol, 1,2-cyclohexanedicarboxylic acid and n-nonanol And 2-ethyl-1-hexanol, mixed ester obtained from 1,2-cyclohexanedicarboxylic acid, n-nonanol and 7-methyl-1-octanol, 1,2-cyclohexanedicarboxylic acid And n-nonanol and 2-methyl-1-octanol Obtained mixed ester, obtained from 1,2-cyclohexanedicarboxylic acid and n-nonanol and isononanol, obtained from 1,2-cyclohexanedicarboxylic acid, n-nonanol and 8-methyl-1-nonanol Mixed group ester, mixed group ester obtained from 1,2-cyclohexanedicarboxylic acid and n-nonanol and isodecanol, mixed group obtained from 1,2-cyclohexanedicarboxylic acid and n-nonanol and 3,5,5-trimethylhexanol Group esters obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-nonanol and 2-methyl-1-propanol, 4-cyclohexene-1,2-dicarboxylic acid and n-nonanol and 3- Mixed group ester obtained from methyl-1-butanol , 4-cyclohexene-1,2-dicarboxylic acid, n-nonanol and 4-methyl-1-pentanol mixed group ester, 4-cyclohexene-1,2-dicarboxylic acid, n-nonanol and 5-methyl A mixed ester obtained from -1-hexanol, a mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid, n-nonanol and 2-methyl-1-hexanol, 4-cyclohexene-1,2- Mixed group ester obtained from dicarboxylic acid and n-nonanol and 6-methyl-1-heptanol, mixed group obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-nonanol and 2-ethyl-1-hexanol Esters, 4-cyclohexene-1,2-dicarboxylic acid and n-nonanol and 7-methyl-1-octano A mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid, n-nonanol and 2-methyl-1-octanol, 4-cyclohexene-1,2-dicarboxylic acid and Mixed ester obtained from n-nonanol and isononanol, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-nonanol and 8-methyl-1-nonanol, 4-cyclohexene-1,2 A mixed ester obtained from dicarboxylic acid and n-nonanol and isodecanol, a mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid, n-nonanol and 3,5,5-trimethylhexanol, 4- Methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 2-methyl- A mixed group ester obtained from 4-propanol, 4-methylcyclohexane-1,2-dicarboxylic acid, n-nonanol and 3-methyl-1-butanol, 4-methylcyclohexane-1,2- Mixed ester obtained from dicarboxylic acid and n-nonanol and 4-methyl-1-pentanol, obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 5-methyl-1-hexanol Mixed group ester, mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 2-methyl-1-hexanol, 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol And 6-methyl-1-heptanol, 4-methylcyclo Mixed ester obtained from hexane-1,2-dicarboxylic acid, n-nonanol and 2-ethyl-1-hexanol, 4-methylcyclohexane-1,2-dicarboxylic acid, n-nonanol and 7-methyl-1- Mixed ester obtained from octanol, mixed ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 2-methyl-1-octanol, 4-methylcyclohexane-1,2-dicarboxylic Mixed group ester obtained from acid and n-nonanol and isononanol, mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 8-methyl-1-nonanol, 4-methylcyclohexane Obtained from -1,2-dicarboxylic acid and n-nonanol and isodecanol Mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 3,5,5-trimethylhexanol, 3-methylcyclohexane-1,2-dicarboxylic acid and n Mixed ester obtained from nonanol and 2-methyl-1-propanol, mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 3-methyl-1-butanol, 3 -Mixyl ester obtained from methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 4-methyl-1-pentanol, 3-methylcyclohexane-1,2-dicarboxylic acid, n-nonanol and 5-methyl -1-Hexanol and mixed ester, 3-methylcyclohexane-1,2 Mixed ester obtained from dicarboxylic acid and n-nonanol and 2-methyl-1-hexanol, and mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 6-methyl-1-heptanol Group esters obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 2-ethyl-1-hexanol, 3-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and Mixed group ester obtained from 7-methyl-1-octanol, Mixed group ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid, n-nonanol and 2-methyl-1-octanol, 3-methylcyclohexane Obtained from -1,2-dicarboxylic acid and n-nonanol and isononanol Mixed group ester, 3-methylcyclohexane-1,2-dicarboxylic acid, n-nonanol and 8-methyl-1-nonanol mixed group ester, 3-methylcyclohexane-1,2-dicarboxylic acid and n- Mixed group ester obtained from nonanol and isodecanol, mixed group ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and 3,5,5-trimethylhexanol, 1,2-cyclohexanedicarboxylic acid , N-nonanol and n-butanol, a mixed ester obtained from 1,2-cyclohexanedicarboxylic acid, n-nonanol and n-pentanol, 1,2-cyclohexanedicarboxylic acid and n- Mixed ester obtained from nonanol and n-hexanol, , 2-cyclohexanedicarboxylic acid, mixed ester obtained from n-nonanol and n-octanol, 1,2-cyclohexanedicarboxylic acid, mixed ester obtained from n-nonanol and n-decanol, 1,2-cyclohexane Mixed ester obtained from dicarboxylic acid and n-nonanol and n-undecanol, Mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-nonanol and n-dodecanol, 4-cyclohexene-1,2-dicarboxylic acid Mixed ester obtained from acid and n-nonanol and n-butanol, Mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-nonanol and n-pentanol, 4-cyclohexene-1, 2-dicarboxylic acid and n-nonanol and n-hex Mixed ester obtained from diol, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-nonanol and n-octanol, 4-cyclohexene-1,2-dicarboxylic acid and n-nonanol and Mixed ester obtained from n-decanol, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-nonanol and n-undecanol, 4-cyclohexene-1,2-dicarboxylic acid and n- Mixed group ester obtained from nonanol and n-dodecanol, mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and n-butanol, 4-methylcyclohexane-1,2-dicarboxylic acid Mixed group ester obtained from acid and n-nonanol and n-pentanol A mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and n-hexanol; obtained from 4-methylcyclohexane-1,2-dicarboxylic acid, n-nonanol and n-octanol Mixed ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and n-decanol, 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and n- Mixed group ester obtained from undecanol, mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and n-dodecanol, 3-methylcyclohexane-1,2-dicarboxylic acid and n- A mixed ester obtained from nonanol and n-butanol, Mixed ester obtained from rucyclohexane-1,2-dicarboxylic acid and n-nonanol and n-pentanol, and mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid, n-nonanol and n-hexanol Group ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and n-octanol, 3-methylcyclohexane-1,2-dicarboxylic acid, n-nonanol and n-decanol Mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and n-undecanol, 3-methylcyclohexane-1,2-dicarboxylic acid and n-nonanol and Examples include mixed ester obtained from n-dodecanol. That.
Moreover, specific examples of the alicyclic dicarboxylic acid diester represented by an alkyl group in which neither of the two alkyl ester groups contains an n-nonyl ester group among the alicyclic dicarboxylic acid diesters include, for example, 1, 2-cyclohexanedicarboxylic acid di (2-methylpropyl), 1,2-cyclohexanedicarboxylic acid di (3-methylbutyl), 1,2-cyclohexanedicarboxylic acid di (4-methylpentyl), 1,2-cyclohexanedicarboxylic acid di (5-methylhexyl), 1,2-cyclohexanedicarboxylic acid di (6-methylheptyl), 1,2-cyclohexanedicarboxylic acid di (2-ethylhexyl), 1,2-cyclohexanedicarboxylic acid di (7-methyloctyl) 1,2-cyclohexanedicarboxylic acid di (2-methyloctyl), 1,2- Chlohexanedicarboxylic acid di (isononyl), 1,2-cyclohexanedicarboxylic acid di (8-methylnonyl), 1,2-cyclohexanedicarboxylic acid di (isodecyl), 1,2-cyclohexanedicarboxylic acid di (3,5,5- Trimethylhexyl), 4-cyclohexene-1,2-dicarboxylic acid di (2-methylpropyl), 4-cyclohexene-1,2-dicarboxylic acid di (3-methylbutyl), 4-cyclohexene-1,2-dicarboxylic acid di (4-methylpentyl), 4-cyclohexene-1,2-dicarboxylic acid di (5-methylhexyl), 4-cyclohexene-1,2-dicarboxylic acid di (6-methylheptyl), 4-cyclohexene-1,2 -Di (2-ethylhexyl) dicarboxylate, 4-cyclohexene-1,2-dicarboxylic acid di (i Nonyl), 4-cyclohexene-1,2-dicarboxylic acid di (isodecyl), 4-cyclohexene-1,2-dicarboxylic acid di (3,5,5-trimethylhexyl), 4-methylcyclohexane-1,2-dicarboxylic acid Acid di (2-methylpropyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (3-methylbutyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (4-methylpentyl), 4-methylcyclohexane -1,2-dicarboxylic acid di (5-methylhexyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (6-methylheptyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (2-ethylhexyl) ), 4-methylcyclohexane-1,2-dicarboxylic acid di (isononyl), 4-methylcyclohexane- 1,2-dicarboxylic acid di (isodecyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (3,5,5-trimethylhexyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (2-methyl) Propyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (3-methylbutyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (4-methylpentyl), 3-methylcyclohexane-1,2-dicarboxylic acid Acid di (5-methylhexyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (6-methylheptyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (2-ethylhexyl), 3-methylcyclohexane -1,2-dicarboxylic acid di (isononyl), 3-methylcyclohexane-1,2-dicarboxylic acid di ( Sodecyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (3,5,5-trimethylhexyl), 1,2-cyclohexanedicarboxylic acid di (n-butyl), 1,2-cyclohexanedicarboxylic acid di (n -Pentyl), 1,2-cyclohexanedicarboxylic acid di (n-hexyl), 1,2-cyclohexanedicarboxylic acid di (n-heptyl), 1,2-cyclohexanedicarboxylic acid di (n-octyl), 1,2- Cyclohexanedicarboxylic acid di (n-decyl), 1,2-cyclohexanedicarboxylic acid di (n-undecyl), 1,2-cyclohexanedicarboxylic acid di (n-dodecyl), 4-cyclohexene-1,2-dicarboxylic acid di ( n-butyl), 4-cyclohexene-1,2-dicarboxylic acid di (n-pentyl), 4-cyclohexene- , 2-dicarboxylic acid di (n-hexyl), 4-cyclohexene-1,2-dicarboxylic acid di (n-heptyl), 4-cyclohexene-1,2-dicarboxylic acid di (n-octyl), 4-cyclohexene- 1,2-dicarboxylic acid di (n-decyl), 4-cyclohexene-1,2-dicarboxylic acid di (n-undecyl), 4-cyclohexene-1,2-dicarboxylic acid di (n-dodecyl), 4-methyl Cyclohexane-1,2-dicarboxylic acid di (n-butyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (n-pentyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (n-hexyl) 4-methylcyclohexane-1,2-dicarboxylic acid di (n-heptyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (n-octyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (n-decyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (n-undecyl), 4-methylcyclohexane-1,2-dicarboxylic acid di (n -Dodecyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (n-butyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (n-pentyl), 3-methylcyclohexane-1,2-dicarboxylic acid Acid di (n-hexyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (n-heptyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (n-octyl), 3-methylcyclohexane-1 , 2-Dicarboxylic acid di (n-decyl), 3-methylcyclohexane-1,2-dicarboxylic acid di (n-undecyl), 3-methyl Cyclohexane-1,2-dicarboxylic acid di (n-dodecyl), 1,2-cyclohexanedicarboxylic acid, n-octanol and 2-methyl-1-propanol mixed group ester, 1,2-cyclohexanedicarboxylic acid and mixed group ester obtained from n-octanol and 3-methyl-1-butanol, mixed group ester obtained from 1,2-cyclohexanedicarboxylic acid and n-octanol and 4-methyl-1-pentanol, 1,2 A mixed ester obtained from cyclohexanedicarboxylic acid and n-octanol and 5-methyl-1-hexanol; a mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-octanol and 2-methyl-1-hexanol 1,2-cyclohexanedicarboxylic acid and n-octano And 6-methyl-1-heptanol, a mixed group ester obtained from 1,2-cyclohexanedicarboxylic acid, n-octanol and 2-ethyl-1-hexanol, 1,2-cyclohexanedicarboxylic acid , A mixed ester obtained from n-octanol and 7-methyl-1-octanol, a mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-octanol and 2-methyl-1-octanol, 1,2 A mixed ester obtained from cyclohexanedicarboxylic acid and n-octanol and isononanol, a mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-octanol and 8-methyl-1-nonanol, 1,2-cyclohexane Dicarboxylic acid and n-octanol and isode Mixed ester obtained from canol, mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-octanol and 3,5,5-trimethylhexanol, 4-cyclohexene-1,2-dicarboxylic acid and n- Mixed ester obtained from octanol and 2-methyl-1-propanol, Mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-octanol and 3-methyl-1-butanol, 4-cyclohexene -1,2-dicarboxylic acid, n-octanol and 4-methyl-1-pentanol mixed group ester, 4-cyclohexene-1,2-dicarboxylic acid, n-octanol and 5-methyl-1-hexanol And 4-cyclohexene-1,2-dicarboxylic acid obtained from A mixed ester obtained from octanol and 2-methyl-1-hexanol, a mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-octanol and 6-methyl-1-heptanol, 4- Mixed ester obtained from cyclohexene-1,2-dicarboxylic acid and n-octanol and 2-ethyl-1-hexanol, 4-cyclohexene-1,2-dicarboxylic acid, n-octanol and 7-methyl-1-octanol Mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-octanol and 2-methyl-1-octanol, 4-cyclohexene-1,2-dicarboxylic acid and n A mixed ester obtained from octanol and isononanol, 4-cyclohex Mixed ester obtained from N-1,2-dicarboxylic acid and n-octanol and 8-methyl-1-nonanol, mixed group obtained from 4-cyclohexene-1,2-dicarboxylic acid, n-octanol and isodecanol Ester, 4-cyclohexene-1,2-dicarboxylic acid and n-octanol and 3,5,5-trimethylhexanol mixed group ester, 4-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 2 A mixed group ester obtained from methyl-1-propanol, a mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid, n-octanol and 3-methyl-1-butanol, 4-methylcyclohexane- 1,2-dicarboxylic acid and n-octanol and 4-methyl-1-pentano Mixed ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid, n-octanol and 5-methyl-1-hexanol, 4-methylcyclohexane-1,2- Mixed ester obtained from dicarboxylic acid and n-octanol and 2-methyl-1-hexanol, and mixed ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 6-methyl-1-heptanol A group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 2-ethyl-1-hexanol, 4-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 4-Methylsic ester, a mixed ester obtained from 7-methyl-1-octanol Mixed ester obtained from hexane-1,2-dicarboxylic acid and n-octanol and 2-methyl-1-octanol, and blend obtained from 4-methylcyclohexane-1,2-dicarboxylic acid, n-octanol and isononanol A group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 8-methyl-1-nonanol, 4-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and Mixed ester obtained from isodecanol, mixed ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 3,5,5-trimethylhexanol, 3-methylcyclohexane-1,2- Dicarboxylic acid and n-octanol and 2-methyl-1- Mixed ester obtained from ropanol, mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 3-methyl-1-butanol, 3-methylcyclohexane-1,2-dicarboxylic Mixed ester obtained from an acid and n-octanol and 4-methyl-1-pentanol, a mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 5-methyl-1-hexanol Group ester, 3-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 2-methyl-1-hexanol mixed group ester, 3-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 3-Methyl-1-heptanol and a mixed ester obtained from 3-methyl Mixed group ester obtained from cyclohexane-1,2-dicarboxylic acid and n-octanol and 2-ethyl-1-hexanol, 3-methylcyclohexane-1,2-dicarboxylic acid, n-octanol and 7-methyl-1- Mixed ester obtained from octanol, 3-
Mixed ester obtained from methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 2-methyl-1-octanol, obtained from 3-methylcyclohexane-1,2-dicarboxylic acid, n-octanol and isononanol Mixed group ester, mixed group ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 8-methyl-1-nonanol, 3-methylcyclohexane-1,2-dicarboxylic acid and n-octanol And a mixed group ester obtained from isodecanol, a mixed group ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-octanol and 3,5,5-trimethylhexanol, 1,2-cyclohexanedicarboxylic acid and n-decanol and 2-methyl-1-pro Mixed ester obtained from diol, mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-decanol and 3-methyl-1-butanol, 1,2-cyclohexanedicarboxylic acid and n-decanol and 4- Mixed ester obtained from methyl-1-pentanol, mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-decanol and 5-methyl-1-hexanol, 1,2-cyclohexanedicarboxylic acid and n A mixed group ester obtained from decanol and 2-methyl-1-hexanol, a mixed group ester obtained from 1,2-cyclohexanedicarboxylic acid and n-decanol and 6-methyl-1-heptanol, 1,2-cyclohexane Dicarboxylic acid and n-decanol and 2-ethyl-1-hexanol Mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-decanol and 7-methyl-1-octanol, 1,2-cyclohexanedicarboxylic acid, n-decanol and 2-methyl- Mixed ester obtained from 1-octanol, Mixed ester obtained from 1,2-cyclohexanedicarboxylic acid, n-decanol and isononanol, 1,2-cyclohexanedicarboxylic acid, n-decanol and 8-methyl-1- Mixed ester obtained from nonanol, mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-decanol and isodecanol, 1,2-cyclohexanedicarboxylic acid and n-decanol and 3,5,5-trimethylhexanol A mixed ester obtained from Mixed ester obtained from cyclohexene-1,2-dicarboxylic acid, n-decanol and 2-methyl-1-propanol, 4-cyclohexene-1,2-dicarboxylic acid, n-decanol and 3-methyl-1-butanol A mixed group ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-decanol and 4-methyl-1-pentanol, 4-cyclohexene-1,2-dicarboxylic acid and Mixed ester obtained from n-decanol and 5-methyl-1-hexanol, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-decanol and 2-methyl-1-hexanol, 4 -Cyclohexene-1,2-dicarboxylic acid, n-decanol and 6-methyl-1-heptanol Mixed ester obtained, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and n-decanol and 2-ethyl-1-hexanol, 4-cyclohexene-1,2-dicarboxylic acid and n-decanol And a mixed group ester obtained from 7-methyl-1-octanol, 4-cyclohexene-1,2-dicarboxylic acid, n-decanol and 2-methyl-1-octanol, 4-cyclohexene- Mixed ester obtained from 1,2-dicarboxylic acid and n-decanol and isononanol, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid, n-decanol and 8-methyl-1-nonanol, 4-cyclohexene-1,2-dicarboxylic acid and n-decanol and isodecanol Mixed ester obtained, 4-cyclohexene-1,2-dicarboxylic acid and n-decanol and 3,5,5-trimethylhexanol mixed ester, 4-methylcyclohexane-1,2-dicarboxylic acid and n Mixed ester obtained from decanol and 2-methyl-1-propanol, mixed ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-decanol and 3-methyl-1-butanol, 4 -Mixyl ester obtained from methylcyclohexane-1,2-dicarboxylic acid and n-decanol and 4-methyl-1-pentanol, 4-methylcyclohexane-1,2-dicarboxylic acid, n-decanol and 5-methyl -1-Hexanol and mixed group ester, 4-methylcyclohexane-1,2-di A mixed ester obtained from carboxylic acid and n-decanol and 2-methyl-1-hexanol, a mixture obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-decanol and 6-methyl-1-heptanol Group esters obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-decanol and 2-ethyl-1-hexanol, 4-methylcyclohexane-1,2-dicarboxylic acid and n-decanol and Mixed group ester obtained from 7-methyl-1-octanol, Mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid, n-decanol and 2-methyl-1-octanol, 4-methylcyclohexane Obtained from -1,2-dicarboxylic acid and n-decanol and isononanol Mixed group ester, mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and n-decanol and 8-methyl-1-nonanol, 4-methylcyclohexane-1,2-dicarboxylic acid and n-decanol And a mixed group ester obtained from isodecanol, a mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid, n-decanol and 3,5,5-trimethylhexanol, 3-methylcyclohexane-1, A mixed ester obtained from dicarboxylic acid and n-decanol and 2-methyl-1-propanol; obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-decanol and 3-methyl-1-butanol Mixed group ester, 3-methylcyclohexane-1,2-dicarboxylic acid and n- Mixed ester obtained from canol and 4-methyl-1-pentanol, mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-decanol and 5-methyl-1-hexanol, 3 A mixed group ester obtained from methylcyclohexane-1,2-dicarboxylic acid and n-decanol and 2-methyl-1-hexanol, 3-methylcyclohexane-1,2-dicarboxylic acid, n-decanol and 6-methyl- Mixed group ester obtained from 1-heptanol, mixed group ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid, n-decanol and 2-ethyl-1-hexanol, 3-methylcyclohexane-1,2 A blend obtained from dicarboxylic acid and n-decanol and 7-methyl-1-octanol Group ester, 3-methylcyclohexane-1,2-dicarboxylic acid, n-decanol and mixed group ester obtained from 2-methyl-1-octanol, 3-methylcyclohexane-1,2-dicarboxylic acid and n-decanol and Mixed ester obtained from isononanol, mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-decanol and 8-methyl-1-nonanol, 3-methylcyclohexane-1,2-dicarboxylic Mixed ester obtained from acid and n-decanol and isodecanol, mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and n-decanol and 3,5,5-trimethylhexanol, 1,2 -Cyclohexanedicarboxylic acid and 2-methyl-1-octanol and -Mixed ester obtained from butanol, mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and 2-methyl-1-octanol and n-pentanol, 1,2-cyclohexanedicarboxylic acid and 2-methyl-1- Mixed group ester obtained from octanol and n-hexanol, mixed group ester obtained from 1,2-cyclohexanedicarboxylic acid and 2-methyl-1-octanol and n-heptanol, 1,2-cyclohexanedicarboxylic acid and 2-methyl- Mixed ester obtained from 1-octanol and n-undecanol, mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and 2-methyl-1-octanol and n-dodecanol, 1,2-cyclohexanedicarboxylic acid and 2- Methyl-1-octanol and 2-me Mixed ester obtained from ru-1-propanol, Mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and 2-methyl-1-octanol and 4-methyl-1-pentanol, 1,2-cyclohexanedicarboxylic Mixed ester obtained from acid and 2-methyl-1-octanol and 2-methyl-1-hexanol, 1,2-cyclohexanedicarboxylic acid, 2-methyl-1-octanol and 5-methyl-1-hexanol Mixed ester obtained, mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and 2-methyl-1-octanol and 2-ethyl-1-pentanol, 1,2-cyclohexanedicarboxylic acid and 2-methyl- Mixed ester obtained from 1-octanol and 2-ethyl-1-hexanol, Mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and 2-methyl-1-octanol and 2-methyl-1-heptanol, 1,2-cyclohexanedicarboxylic acid, 2-methyl-1-octanol and isooctanol Mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and 2-methyl-1-octanol and isononanol, 1,2-cyclohexanedicarboxylic acid and 2-methyl-1-octanol and 3, A mixed group ester obtained from 5,5-trimethyl-1-hexanol, a mixed group ester obtained from 1,2-cyclohexanedicarboxylic acid and 2-methyl-1-octanol and isodecanol, and 1,2-cyclohexanedicarboxylic acid 2-methyl-1-octanol and isou Mixed group ester obtained from decanol, 4-cyclohexene-1,2-dicarboxylic acid and 2-methyl-1-octanol and n-butanol, 4-cyclohexene-1,2-dicarboxylic acid and 2 Mixed ester obtained from methyl-1-octanol and n-pentanol, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and 2-methyl-1-octanol and n-hexanol, 4-cyclohexene Mixed group ester obtained from -1,2-dicarboxylic acid, 2-methyl-1-octanol and n-heptanol, obtained from 4-cyclohexene-1,2-dicarboxylic acid, 2-methyl-1-octanol and n-undecanol Mixed ester, 4-cyclohexene-1,2-dicarboxylic acid and 2- Mixed ester obtained from til-1-octanol and n-dodecanol, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and 2-methyl-1-octanol and 2-methyl-1-propanol, 4 -Cyclohexene-1,2-dicarboxylic acid, 2-methyl-1-octanol and 4-methyl-1-pentanol mixed group ester obtained from 4-cyclohexene-1,2-dicarboxylic acid and 2-methyl-1 Mixed ester obtained from octanol and 2-methyl-1-hexanol, mixed group obtained from 4-cyclohexene-1,2-dicarboxylic acid and 2-methyl-1-octanol and 5-methyl-1-hexanol Esters, 4-cyclohexene-1,2-dicarboxylic acid and 2-methyl-1-octanol and 2-ethyl Mixed ester obtained from til-1-pentanol, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid, 2-methyl-1-octanol and 2-ethyl-1-hexanol, 4- Cyclohexene-1,2-dicarboxylic acid and 2-methyl-1-oct
Mixed ester obtained from tanol and 2-methyl-1-heptanol, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid, 2-methyl-1-octanol and isooctanol, 4-cyclohexene- Mixed ester obtained from 1,2-dicarboxylic acid and 2-methyl-1-octanol and isononanol, 4-cyclohexene-1,2-dicarboxylic acid, 2-methyl-1-octanol and 3,5,5-trimethyl Mixed ester obtained from -1-hexanol, mixed ester obtained from 4-cyclohexene-1,2-dicarboxylic acid, 2-methyl-1-octanol and isodecanol, 4-cyclohexene-1,2-dicarboxylic acid And 2-methyl-1-octanol and isoundecanol Group ester, 3-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and mixed group ester obtained from n-butanol, 3-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1 Mixed ester obtained from octanol and n-pentanol, mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and n-hexanol, 3-methylcyclohexane-1 , 2-dicarboxylic acid, 2-methyl-1-octanol and n-heptanol mixed group ester, 3-methylcyclohexane-1,2-dicarboxylic acid, 2-methyl-1-octanol and n-undecanol Mixed ester, 3-methylcyclohexane-1,2-dicarbo Mixed ester obtained from acid and 2-methyl-1-octanol and n-dodecanol, obtained from 3-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and 2-methyl-1-propanol Mixed group ester, 3-methylcyclohexane-1,2-dicarboxylic acid, 3-methylcyclohexane-1,2-dicarboxylic acid mixed ester obtained from 2-methyl-1-octanol and 4-methyl-1-pentanol Mixed ester obtained from acid and 2-methyl-1-octanol and 2-methyl-1-hexanol, 3-methylcyclohexane-1,2-dicarboxylic acid, 2-methyl-1-octanol and 5-methyl-1 -Mixed ester obtained from hexanol, 3-methylcyclohexane-1,2-dicarboxylic acid Mixed ester obtained from 2-methyl-1-octanol and 2-ethyl-1-pentanol, 3-methylcyclohexane-1,2-dicarboxylic acid, 2-methyl-1-octanol and 2-ethyl-1 Mixed ester obtained from hexanol, mixed ester obtained from 3-methylcyclohexane-1,2-dicarboxylic acid, 2-methyl-1-octanol and 2-methyl-1-heptanol, 3-methylcyclohexane- Mixed ester obtained from 1,2-dicarboxylic acid and 2-methyl-1-octanol and isooctanol, obtained from 3-methylcyclohexane-1,2-dicarboxylic acid, 2-methyl-1-octanol and isononanol Mixed ester, 3-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl Mixed ester obtained from 1-octanol and 3,5,5-trimethyl-1-hexanol, mixed group obtained from 3-methylcyclohexane-1,2-dicarboxylic acid, 2-methyl-1-octanol and isodecanol Ester, 3-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and isoundecanol mixed group ester, 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl- Mixed ester obtained from 1-octanol and n-butanol, Mixed ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and n-pentanol, 4-methylcyclohexane- 1,2-dicarboxylic acid and 2-methyl-1-octanol and n-he Mixed group ester obtained from sanol, 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and n-heptanol mixed group ester, 4-methylcyclohexane-1,2-dicarboxylic acid Mixed group ester obtained from 2-methyl-1-octanol and n-undecanol, mixed group ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and n-dodecanol, 4- Mixed group ester obtained from methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and 2-methyl-1-propanol, 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1- Mixed group S obtained from octanol and 4-methyl-1-pentanol Ter, 4-methylcyclohexane-1,2-dicarboxylic acid, 2-methyl-1-octanol and 2-methyl-1-hexanol mixed group ester, 4-methylcyclohexane-1,2-dicarboxylic acid and 2 -Mix-1-esters obtained from methyl-1-octanol and 5-methyl-1-hexanol, 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and 2-ethyl-1-pentanol Mixed ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid, 2-methyl-1-octanol and 2-ethyl-1-hexanol, 4-methylcyclohexane-1, Obtained from 2-dicarboxylic acid and 2-methyl-1-octanol and 2-methyl-1-heptanol Mixed ester obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and isooctanol, 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl A mixed ester obtained from -1-octanol and isononanol, a mixture obtained from 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and 3,5,5-trimethyl-1-hexanol Group ester, 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1-octanol and isodecanol mixed group ester, 4-methylcyclohexane-1,2-dicarboxylic acid and 2-methyl-1- Mixed group ester obtained from octanol and isoundecanol, etc. And the like.

  In the present specification and claims, the “mixed group ester” means a diester in which R1 and R2 are composed of different alkyl groups as described in the general formula (1). For example, in the above example of “mixed ester obtained from 1,2-cyclohexanedicarboxylic acid and n-nonanol and 2-methyl-1-octanol”, in general formula (1), one of R1 and R2 is n -Means a non-ester, and the other is a diester represented by a 2-methyloctyl group. In the present specification and claims, it may be expressed as 1,2-cyclohexanedicarboxylic acid (2-methyloctyl) (n-nonyl).

[Automotive lubricating oil composition]
The automotive lubricating oil composition of the present invention contains a hydrocarbon base oil and two or more alicyclic dicarboxylic acid diesters represented by the general formula (1), and the two or more alicyclic dicarboxylic acids. The acid diester includes an alicyclic dicarboxylic acid diester in which at least ^one of R ¹ and R ² in the general formula (1) is represented by an n-nonyl group, and the total content of the alicyclic dicarboxylic acid diester is 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight, more preferably 1 to 8 parts by weight, or carbonized with respect to 100 parts by weight of hydrocarbon base oil Hydrogen base oil, alicyclic dicarboxylic acid represented by the above general formula (2), n-nonanol, and linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol). ) And esterification reaction The alicyclic dicarboxylic acid diester is contained, and the content of the alicyclic dicarboxylic acid diester is 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight based on 100 parts by weight of the hydrocarbon base oil. More preferably, it is contained in the range of 1 to 8 parts by weight.

  The kinematic viscosity at 100 ° C. of the automotive lubricating oil composition of the present invention is preferably 1.5 to 40 mm 2 / s, more preferably 2.5 to 30 mm 2 / s.

  The viscosity index of the automotive lubricating oil composition of the present invention is preferably 80 to 160, more preferably 100 to 160.

  The pour point of the automotive lubricating oil composition of the present invention is preferably -15 ° C or lower, more preferably -30 ° C or lower, particularly -40 ° C or lower.

  The flash point of the automotive lubricating oil composition of the present invention is preferably 200 ° C. or higher.

The automotive lubricating oil composition of the present invention has a good balance of the performances of heat-resistant oxidation stability, high-temperature cleanability, water resistance and material compatibility as compared with conventionally known automotive lubricating oils, and low-temperature storage stability. Is also good. These performances are characteristic requirements unique to automotive applications.
Thermal oxidation stability is one of the important performance requirements for all automotive applications used in a relatively high temperature range. The lower the evaluation value of the heat-resistant oxidation stability described later, the less oxidative deterioration of the lubricating oil occurs, and the operating time or usage time can be prolonged.
High temperature cleanliness is one of the important performance requirements, especially in engine applications. The higher the high-temperature detergency evaluation value score described below, the smaller the amount of coke, the higher the solubilization effect of oxidized degradation products generated when using lubricating oil, indicating that it is excellent in cleanliness. Yes.
Water resistance is one of the important performance requirements in general automotive applications. This is because, when the lubricating oil is used for a long period of time, moisture may be mixed in or absorbed, resulting in hydrolysis of the ester compound. As a result, the hydrolyzate may hinder long-term operation and use. It means that hydrolysis of the alicyclic dicarboxylic acid diester itself is suppressed as the evaluation value of the water resistance described later is lower, and the water resistance as a lubricating oil is favorably affected.
Material compatibility is one of the important performance requirements in general automotive applications. In automotive applications, rubber materials are frequently used as sealing members at locations where lubricating oil is used. The sealing member also has a role of preventing swelling of the lubricating oil by appropriately swelling with the lubricating oil. The material compatibility evaluation method described later is a method for evaluating this “appropriate swelling”.

  In addition to the hydrocarbon base oil and the alicyclic dicarboxylic acid diester represented by the general formula (1), the lubricating oil composition for automobiles of the present invention includes other conventionally known base oils (hereinafter referred to as “combined base oils”). Or a lubricating oil additive can be used in combination or added within the range of the effects of the present invention.

  The use of the combined base oil is used by replacing a part of the intended use amount of the hydrocarbon base oil according to the present invention. When the combined base oil is used, the amount used is preferably 30% by weight or less, more preferably 20% by weight or less, based on the total weight of the hydrocarbon base oil according to the present invention and the combined base oil. A range of 10% by weight or less is recommended.

  Examples of the combined base oil include animal and vegetable oils, organic acid esters other than the present ester, polyalkylene glycol, polyvinyl ether, polyphenyl ether, alkylphenyl ether, and silicone oil. Such combined base oils can be used alone or in combination of two or more.

  Examples of animal and vegetable oils include beef tallow, lard, palm oil, coconut oil, rapeseed oil, castor oil, sunflower oil and the like.

Examples of organic acid esters other than the alicyclic dicarboxylic acid diesters according to the present invention include fatty acid monoesters, aliphatic dibasic acid diesters, and polyol esters.
The fatty acid monoester is obtained from an aliphatic linear or branched monocarboxylic acid having 5 to 22 carbon atoms and a linear or branched saturated or unsaturated aliphatic alcohol having 3 to 22 carbon atoms. And monoesters that can be used. Aliphatic dibasic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonanedioic acid, decanedioic acid Examples thereof include diesters obtained from an acid and a linear or branched saturated or unsaturated aliphatic alcohol having 3 to 22 carbon atoms. Further, as the polyol ester, neopentyl glycol such as neopentyl glycol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol and the like, and linear and / or branched saturated or 3 to 22 carbon atoms or Examples thereof include polyol esters obtained from unsaturated fatty acids.
Examples of the esters other than the above include polymerized fatty acids such as dimer acid and hydrogenated dimer acid, or hydroxy fatty acids such as condensed castor oil fatty acid and hydrogenated condensed castor oil fatty acid, and linear or branched chain having 3 to 22 carbon atoms. Examples thereof include ester compounds with saturated or unsaturated aliphatic alcohols.

  Examples of the polyalkylene glycol include a ring-opening polymer of alcohol and a linear or branched alkylene oxide having 2 to 4 carbon atoms. Examples of the alkylene oxide include ethylene oxide, propylene oxide, and butylene oxide, and a polymer using one of these or a copolymer using two or more types can be used. A compound in which one or both hydroxyl groups are etherified or esterified can also be used. The kinematic viscosity (40 ° C.) of the polymer is usually 5 to 1000 mm 2 / s, preferably 5 to 500 mm 2 / s.

  Polyvinyl ether is a compound obtained by polymerization of a vinyl ether monomer, and monomers include methyl vinyl ether, ethyl vinyl ether, 2-propyl vinyl ether, 1-butyl vinyl ether, 2-methyl-1-propyl vinyl ether, 2-butyl vinyl ether, 2 -Methyl-2-propyl vinyl ether, 1-pentyl vinyl ether, 1-hexyl vinyl ether, 2-methoxyethyl vinyl ether, 2-ethoxyethyl vinyl ether and the like. The kinematic viscosity (40 ° C.) of the polymer is usually 5 to 1000 mm 2 / s, preferably 5 to 500 mm 2 / s.

  Examples of polyphenyl ether include compounds having a structure in which meta positions of two or more aromatic rings are connected by an ether bond or a thioether bond. Specifically, bis (m-phenoxyphenyl) ether, m-bis ( m-phenoxyphenoxy) benzene, and thioethers (commonly referred to as C-ether) in which one or more of these oxygens are substituted with sulfur.

  Examples of the alkyl phenyl ether include compounds in which polyphenyl ether is substituted with a linear or branched alkyl group having 6 to 18 carbon atoms, and alkyl diphenyl ether substituted with one or more alkyl groups is particularly preferable.

  Examples of the silicone oil include dimethyl silicone and methylphenyl silicone, and modified silicones such as long-chain alkyl silicone and fluorosilicone.

  Among these combined base oils, heat resistance and lubricity may be improved when the organic acid ester is used in combination.

  In order to further improve the performance of the automotive lubricating oil composition of the present invention, known antioxidants, metal detergents, ashless dispersants, oiliness agents, antiwear agents, extreme pressure agents, metal deactivators Addition of lubricating oil additives such as rust inhibitors, viscosity index improvers, pour point depressants, antifoaming agents, etc., alone or in combination of two or more, within the scope of the effects of the present invention. Is possible.

  Antioxidants include 2,6-di-tert-butyl-p-cresol, 2-tert-butyl-4-hydroxyanisole, 2,5-di-tert-butylhydroquinone, 4-hydroxymethyl-2,6 -Phenols such as di-tert-butylphenol, 4,4'-methylenebis-2,6-di-tert-butylphenol, 2,2'-methylenebis-4-methyl-6-tert-butylphenol, N-phenyl-α Examples thereof include amine compounds such as naphthylamine and p, p′-dioctyldiphenylamine, and sulfur compounds such as p, p′-dinonyldiphenylamine, mixed dialkyldiphenylamine and phenothiazine. These antioxidants can be used alone or in combination of two or more. When these antioxidants are used, the amount used is usually 100 parts by weight of the hydrocarbon base oil according to the present invention (the total amount including the combined base oil when the combined base oil is used). It is recommended to add 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight.

  Metal detergents include Ca-petroleum sulfonate, overbased Ca-petroleum sulfonate, Ca-alkyl benzene sulfonate, overbased Ca-alkyl benzene sulfonate, Ba-alkyl benzene sulfonate, over-based Ba-alkyl benzene sulfonate. Phonate, Mg-alkylbenzenesulfonate, overbased Mg-alkylbenzenesulfonate, Na-alkylbenzenesulfonate, overbased Na-alkylbenzenesulfonate, Ca-alkylnaphthalenesulfonate, overbased Ca- Metal sulfonates such as alkyl naphthalene sulfonates, Ca-phenates, overbased Ca-phenates, Ba-phenates, overbased Ba-phenates and other metal phenates, Ca-salicylate, overbased C Metal salicylates such as salicylates, Ca-phosphonates, overbased Ca-phosphonates, Ba-phosphonates, overbased Ba-phosphonates and other metal phosphonates, overbased Ca-carboxylates Etc. are exemplified. These metal detergents can be used individually or in combination of 2 or more types as appropriate. When these metal detergents are used, the amount used is usually 100 parts by weight of the hydrocarbon base oil according to the present invention (the total amount including the combined base oil when the combined base oil is used). It is recommended to add 1 to 10 parts by weight, preferably 2 to 7 parts by weight.

  Examples of the ashless dispersant include polyalkenyl succinimide, polyalkenyl succinamide, polyalkenyl benzylamine, polyalkenyl succinate and the like. These ashless dispersants can be used alone or in combination of two or more. When these ashless dispersants are used, the amount used is usually 100 parts by weight of the hydrocarbon base oil according to the present invention (the total amount including the combined base oil when the combined base oil is used). It is desirable to add 1 to 10 parts by weight, preferably 2 to 7 parts by weight.

  Examples of oily agents include aliphatic saturated and unsaturated monocarboxylic acids such as stearic acid and oleic acid, polymerized fatty acids such as dimer acid and hydrogenated dimer acid, hydroxy fatty acids such as ricinoleic acid and 12-hydroxystearic acid, lauryl alcohol, Aliphatic saturated and unsaturated monoalcohols such as oleyl alcohol, aliphatic saturated and unsaturated monoamines such as stearylamine and oleylamine, aliphatic saturated and unsaturated monocarboxylic amides such as lauric acid amide, oleic acid amide, batyl alcohol, Glycerol ethers such as chimyl alcohol and ceralkyl alcohol, alkyl or alkenyl polyglyceryl ethers such as lauryl polyglyceryl ether and oleyl polyglyceryl ether, di (2-ethylhexyl) monoethanolamine , Poly (alkylene oxide) alkyl or alkenyl amines such as diisotridecyl monoethanolamine adduct and the like. These oily agents may be used alone or in appropriate combination of two or more. When these oil-based agents are used, the amount used is usually 0 with respect to 100 parts by weight of the hydrocarbon base oil according to the present invention (the total amount including the combined base oil when the combined base oil is used). It is recommended to add 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight.

  Antiwear / extreme pressure agents include tricresyl phosphate, cresyl diphenyl phosphate, alkylphenyl phosphates, phosphate esters such as tributyl phosphate, dibutyl phosphate, tributyl phosphate, dibutyl phosphate, triisopropyl phosphate, etc. Phosphorous esters of these and phosphorus salts such as amine salts thereof, sulfurized fatty acids such as sulfurized fats and oils, sulfurized oleic acid, sulfurous systems such as dibenzyl disulfide, sulfurized olefin and dialkyl disulfide, Zn-dialkyldithiophosphate, Zn- Examples thereof include organometallic compounds such as dialkyldithiophosphate, Mo-dialkyldithiophosphate, and Mo-dialkyldithiocarbamate. These antiwear agents can be used alone or in combination of two or more. When these antiwear / extreme pressure agents are used, the amount used is usually the hydrocarbon base oil according to the present invention (the total amount including the combined base oil when the combined base oil is used). It is desirable to add 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight with respect to parts.

  Examples of the metal deactivator include benzotriazole-based, thiadiazole-based, and gallic acid ester-based compounds. These metal deactivators can be used alone or in appropriate combination of two or more. When these metal deactivators are used, the amount used is usually 0.01 to 100 parts by weight based on 100 parts by weight of a lubricating base oil (in the case of using a combined base oil, the combined base oil is included). It is recommended to add 0.4 parts by weight, preferably 0.01 to 0.2 parts by weight.

  Antirust agents include alkyl or alkenyl succinic acid derivatives such as dodecenyl succinic acid half ester, octadecenyl succinic anhydride, dodecenyl succinic acid amide, sorbitan monooleate, glycerin monooleate, pentaerythritol monooleate Partial alcohol ester, Ca-petroleum sulfonate, Ca-alkyl benzene sulfonate, Ba-alkyl benzene sulfonate, Mg-alkyl benzene sulfonate, Na-alkyl benzene sulfonate, Zn-alkyl benzene sulfonate, Ca-alkyl naphthalene sulphate Examples thereof include metal sulfonates such as phonates, amines such as rosinamine and N-oleylsarcosine, dialkyl phosphiteamine salts, and the like. These rust inhibitors can be used alone or in combination of two or more. When using these rust preventives, the amount used is usually 100 parts by weight of the hydrocarbon base oil according to the present invention (the total amount including the combined base oil when the combined base oil is used). It is recommended to add 0.01 to 5 parts by weight, preferably 0.05 to 2 parts by weight.

  Examples of the viscosity index improver include olefin copolymers such as polyalkyl methacrylate, polyalkyl styrene, polybutene, ethylene-propylene copolymer, styrene-diene copolymer, and styrene-maleic anhydride ester copolymer. . These viscosity index improvers can be used alone or in combination of two or more. When these viscosity index improvers are used, the amount used is usually 100 parts by weight of the hydrocarbon base oil according to the present invention (the total amount including the combined base oil when the combined base oil is used). It is recommended to add 0.1 to 15 parts by weight, preferably 0.5 to 7 parts by weight.

  Examples of the pour point depressant include condensates of chlorinated paraffin and alkyl naphthalene, condensates of chlorinated paraffin and phenol, polyalkyl methacrylate, polyalkyl styrene, polybutene and the like as viscosity index improvers. These pour point depressants can be used alone or in combination of two or more. When these pour point improvers are used, the amount used is usually 100 parts by weight of the hydrocarbon base oil according to the present invention (the total amount including the combined base oil when the combined base oil is used). It is desirable to add 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight.

  As the antifoaming agent, liquid silicone is suitable, and when an antifoaming agent is used, the amount added is usually a lubricating base oil (including the combined base oil when a concomitant base oil is used). It is recommended to add 0.0005 to 0.01 parts by weight with respect to parts by weight.

  The thus obtained automotive lubricating oil composition of the present invention has a good balance of thermal oxidation stability, high temperature cleanliness, water resistance and material compatibility among the required performances required for automotive lubricating oil, and low temperature storage stability. Since the property is also good, it can be optimally used for automobile applications. Among them, engine, transmission, or shock absorber lubricant applications are more effective, and engine lubricant applications are most useful.

  EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the examples and comparative examples, various properties of the ester compound, physical properties and chemical properties of the lubricating oil were measured or evaluated by the following methods. Reagents were used for compounds not specifically mentioned.

(A) Composition analysis of ester The ester composition was analyzed using gas chromatography under the following conditions. The area ratio of the obtained gas chromatogram was used as the ester composition ratio.
Measuring condition equipment: GC-2010 manufactured by Shimadzu Corporation
Column used: J & W TC-5 30m x 0.25mm
Column temperature: 100 to 300 ° C. (temperature rising rate 20 ° C./min)
Injection temperature / detection temperature: 300 ° C / 300 ° C
Detector: FID
Carrier gas: Helium Gas flow rate: 0.97 mL / min

(B) Total acid value / hydroxyl value / sulfate ash content The total acid value was measured in accordance with JIS K2501 (2003), the hydroxyl value was measured in accordance with JIS K0070 (1992), and the sulfated ash content was measured in accordance with JIS K2272 (1998).

(C) Kinematic viscosity Kinematic viscosity at 40 ° C and 100 ° C was measured according to JIS K2283 (2000). However, the 0 ° C. kinematic viscosity was calculated from the viscosity-temperature relationship defined in JIS K2283 (2000).

(D) Viscosity index Calculated according to JIS K2283 (2000).

(E) Low temperature fluidity test The pour point was measured according to JIS K2269 (1987).

(F) Flash point Measured according to JIS K2265-4 (Cleveland release type, 2007).

(G) Heat-resistant oxidation stability test 2,6-di-tert-butyl-p-cresol as an antioxidant was added to 100 parts by weight of a mixed oil composed of a hydrocarbon base oil and an ester having a composition ratio shown in Table 2. And p, p′-dioctyldiphenylamine was added to each test part to prepare a test lubricating oil. Since the test is usually performed by adding an additive such as an antioxidant, the same additive was blended in the examples and comparative examples, and a comparative test was performed. Put 0.2g of test lubricant and steel, aluminum and copper wires cut into 2mm lengths into a glass test tube with an inner diameter of 33mm and a height of 85mm. A clasp was attached so that there was no. The test tube was placed in an oven and heated at 190 ° C. for 20 hours. The acid value of the lubricating oil after the test was measured to obtain a difference from the previously measured acid value before the test, and the difference was defined as the acid value increase value. It is determined that the smaller the acid value increase value (mgKOH / g), the better the thermal oxidation stability.
Increase in acid value (mgKOH / g) = acid value after test-acid value before test

(H) High-temperature cleanliness test A hot tube tester (manufactured by Komatsu Engineering Co., Ltd.) was used for evaluation. To 100 parts by weight of a mixed oil composed of a hydrocarbon base oil and an ester having the composition ratio shown in Table 2, 4,4′-methylenebis (2,6-di-tert-butylphenol) and p, p ′ as antioxidants -A lubricating oil for testing was prepared by adding 0.5 parts by weight of dioctyldiphenylamine. Since the test is usually performed by adding an additive such as an antioxidant, the same additive was blended in the examples and comparative examples, and a comparative test was performed. The inside of the glass tube is kept at 290 ° C., and the lubricating oil is injected at a rate of 0.31 mL / hour and air at a rate of 10 mL / minute for 16 hours. After the test, the glass tube was washed with n-hexane and sufficiently dried, and then the stain was determined as a color score (0 to 10 points) by comparing with a score sample. Moreover, the weight increase of the glass tube was made into coke amount (mg). At this time, the higher the score or the smaller the amount of coke, the better the high temperature cleanability.

(I) Material compatibility test 2,6-di-tert-butyl-p-cresol as an antioxidant was added to 100 parts by weight of a mixed oil composed of a hydrocarbon base oil and an ester having the composition ratio shown in Table 2. A test lubricating oil prepared by adding 0 part by weight was prepared. Since the test is usually performed by adding an additive such as an antioxidant, the same additive was blended in the examples and comparative examples to perform test evaluation. Put 50g of test lubricant and sheet-like nitrile rubber (20mm x 20mm, 1mm thickness) into a glass test tube with an inner diameter of 33mm and a height of 85mm. Was attached. The test tube was placed in an oven and heated at 120 ° C. for 72 hours. After the test, the rubber was taken out and washed with n-hexane, then the n-hexane was volatilized with cold air, and further stored for 1 hour at room temperature and normal pressure in a desiccator, and then the weight increase of the rubber was measured. The larger the rate of change in weight (% by weight) before and after the test, the greater the swelling property to rubber. In addition, when a weight change rate becomes a negative value, it is judged that there is no practicality. The weight change rate (% by weight) was calculated according to the following formula.
Weight change rate (% by weight) = (weight of rubber changed before and after the test / weight of rubber before the test) × 100

(J) Evaluation of water resistance An iron, copper, and aluminum wire having a length of 4 cm is placed in a glass test tube having an inner diameter of 6.6 mm and a height of 30 cm, and each ester or hydrocarbon base oil shown in Table 1 is added in 2. Weigh 0 g and 0.2 g of distilled water. The test tube is sealed while degassing with an aspirator, placed in an oven and heated at 175 ° C. for 40 hours. The acid value of the ester after the test was measured to determine the difference from the acid value before the test. A smaller acid value increase value (mgKOH / g) indicates better hydrolysis resistance of the ester itself. And since this value is a value that can be relatively evaluated as an index that directly reflects the water resistance of the automotive lubricating oil composition of the present invention, the water resistance evaluation of the automotive lubricating oil composition of the present invention Can be considered.
Increase in acid value (mgKOH / g) = acid value after test-acid value before test

(K) Evaluation of low-temperature storage stability A mixed oil composed of a hydrocarbon base oil and an ester having a composition ratio shown in Table 2 was left in a thermostatic bath at -30 ° C for 24 hours. A case where no precipitate was confirmed was indicated as “◯”, and a case where a precipitate was confirmed was indicated as “x”.

[Production Example 1]
In a four-necked flask equipped with a stirrer, thermometer, and Dean-Stark water separator, 231 g (1.5 mol) of 1,2-cyclohexanedicarboxylic anhydride and “LINEVOL9” as the alcohol component (Product) (Name, manufactured by Shell Chemicals) 475.2 g (3.3 mol), xylene as a water entraining agent, an amount corresponding to 5% by weight based on the raw material, and a tin oxide catalyst as an esterification catalyst. An amount corresponding to 2% by weight was charged and the atmosphere was replaced with nitrogen, and then the temperature was gradually raised to 210 ° C. with stirring in a nitrogen atmosphere. While removing water generated as a by-product during the esterification reaction with a water separator, the esterification reaction is performed at normal pressure for 5 hours, and the reaction is continued for 5 hours under reduced pressure (0.02 MPa) while maintaining 210 ° C. The acid value of the reaction mixture was 1 mg KOH / g or less, and an esterified crude product was obtained.
Next, post-treatment of the esterified crude product was performed. First, xylene and excess alcohol components of the raw material are distilled off from the esterified crude product under reduced pressure conditions of 180 ° C. and 1330 Pa, 30 g of 5% aqueous sodium hydroxide solution is added to the resulting liquid residue, and the mixture is stirred at 80 ° C. for 2 hours. Neutralization was performed by performing. The neutralized product was repeatedly washed with water until the water layer of the washing water became neutral to obtain a liquid material. Next, activated alumina was added, stirred and adsorbed, and then subjected to suction filtration to obtain 592 g of an ester mixture (hereinafter referred to as “ester A”).
The acid value of ester A was 0.01 mgKOH / g, the hydroxyl value was less than 1 mgKOH / g, and the sulfated ash content was less than 30 ppm. The composition of ester A was as follows from the gas chromatogram.
Ester A;
(A) 1,2-cyclohexanedicarboxylic acid di (2-methyloctyl)
(B) 1,2-cyclohexanedicarboxylic acid (2-methyloctyl) (n-nonyl)
(C) 1,2-cyclohexanedicarboxylic acid di (n-nonyl)
(A) / (b) / (c) = 6.1 / 10.5 / 83.4 (area%)

[Production Example 2]
1,2-Cyclohexanedicarboxylic acid di (n-decyl) (hereinafter referred to as “ester”) in the same manner as in Production Example 1 except that the alcohol component of the raw material used was only 521.4 g (3.3 mol) of n-decanol. a)) was obtained. The acid value of the reaction mixture at the end of the esterification reaction was 1 mgKOH / g or less.
The acid value of ester a was 0.01 mgKOH / g, the hydroxyl value was less than 1 mgKOH / g, and the sulfated ash content was less than 30 ppm.

[Properties of ester]
Table 1 shows the measurement results of kinematic viscosity, viscosity index, pour point and flash point of each ester.

[Examples 1 to 3, Comparative Examples 1 to 4]
Each of the esters and the hydrocarbon base oil were mixed so that the composition ratio shown in Table 2 was obtained, thereby preparing the automotive lubricating oil composition of the present invention or the lubricating oil outside the present invention.
Measurement results of kinematic viscosity, viscosity index, pour point and flash point, and low-temperature storage stability, heat-resistant oxidation stability, high-temperature cleanability, material compatibility and The evaluation results of water resistance are shown in Table 2. The “ester b” and the hydrocarbon base oil used are as follows.
Ester b: “Nugelbu TP-320” (product name, manufactured by Shin Nippon Rika Co., Ltd., a triester mixture obtained from trimethylolpropane, 1-octanoic acid and 1-decanoic acid)
・ PAO; "SpectraSyn4" (product name, manufactured by ExxonMobil Chemical)
Mineral oil: “Cosmo Neutral 100” (product name, manufactured by Cosmo Oil Lubricants)

From Table 1, it can be seen that ester A has a high viscosity index of 100 or more, has a small increase in viscosity at low temperature, and is excellent in fluidity at low temperature.
From the comparative example shown in Table 2, when the polyol ester that has been conventionally known as a lubricant additive for automobiles is used, the viscosity characteristics and lubrication characteristics are at a good level, but the high temperature cleanliness and material compatibility It turns out that the water resistance is slightly low and there is room for improvement. It can also be seen that when a diester compound using only a linear alcohol is used, the effect of imparting storage stability at low temperatures is not at a sufficient level.
On the other hand, by blending the alicyclic dicarboxylic acid diester of the present invention as a lubricating oil additive for automobiles, with respect to hydrocarbon base oil, while maintaining high lubricating performance, heat-resistant oxidation stability, high temperature cleanliness, It can be seen that water resistance and material compatibility are imparted (or improved) in a well-balanced manner. And it can be said that it is the feature that there exists those effects in the range whose usage-amount (blending amount) is a comparatively small amount.
In addition, the automotive lubricating oil composition containing the alicyclic dicarboxylic acid diester of the present invention has high lubricating performance as compared with a lubricating oil composed of a hydrocarbon base oil and a polyol ester that has been conventionally used. It has a good balance of heat-resistant oxidation stability, high-temperature cleanability, water resistance and material compatibility (swellability to an appropriate rubber), and low-temperature storage stability is also good.

  The lubricating oil additive for automobiles of the present invention maintains high lubricating performance against hydrocarbon base oils in a small amount of addition, while maintaining heat oxidation stability, high temperature cleanliness, water resistance, and material compatibility. It can be applied (or improved) in a well-balanced manner, and in addition, an economic contribution is possible, which is best for automotive applications. In addition, the automotive lubricating oil composition of the present invention has high lubricating performance, a good balance of thermal oxidation stability, high temperature cleanliness, water resistance and material compatibility, and low temperature storage stability. Therefore, it is most suitable for automobile use. Among these, it is effective for applications for engines, transmissions, or shock absorbers.

Claims (6)

Hydrocarbon base oil and general formula (2)

[Wherein, A represents a cyclohexane ring or a cyclohexene ring, and X represents a hydrogen atom or a methyl group. ]
It is obtained by esterifying the alicyclic dicarboxylic acid represented by the formula: n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol). And a lubricating oil composition for automobiles, wherein the alicyclic dicarboxylic acid diester is contained in a range of 0.5 to 20 parts by weight with respect to 100 parts by weight of the hydrocarbon base oil. object. The ratio (molar ratio) between n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol) is in the range of 95: 5 to 50:50. The automotive lubricating oil composition according to claim 1. Lubricant for automobiles according to claim 1 or 2, wherein the branched or saturated aliphatic saturated alcohol having 4 to 12 carbon atoms contains the branched or saturated aliphatic alcohol having 9 carbon atoms as an essential component. Oil composition. General formula (2)

[Wherein, A represents a cyclohexane ring or a cyclohexene ring, and X represents a hydrogen atom or a methyl group. ]
It is obtained by esterifying the alicyclic dicarboxylic acid represented by the formula: n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol). Lubricating oil additive for automobiles comprising the produced alicyclic dicarboxylic acid diester. The ratio (molar ratio) between n-nonanol and a linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms (excluding n-nonanol) is in the range of 95: 5 to 50:50. The automobile lubricant additive according to claim 4. The lubricating for automobiles according to claim 4 or 5, wherein the branched aliphatic saturated alcohol having 9 to 9 carbon atoms is contained in the linear or branched aliphatic saturated alcohol having 4 to 12 carbon atoms as an essential component. Oil additive.