JP2012224653A - Lubricating base oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide lubricating base oil which can satisfactorily dissolve a lubricating oil additive, and can achieve the coexistence of a low dynamic viscosity and a high viscosity index in a higher dimension.SOLUTION: The lubricating base oil includes: (A) 10 to 70 mass% of specified fatty acid polyalkylene alkyl ether having a narrow ratio of 55 to 80%; (B) 5 to 60 mass% of specified fatty acid alkyl ester; and (C) 5 to 60 mass% of fatty acid polyol ester obtained by ester-interexchanging specified fatty acid or fatty acid alkyl ester with specified polyhydric alcohol.

Description

  The present invention relates to a lubricating base oil.

In general, hydrocarbon-based base oils such as mineral oil and PAO (synthetic lubricating oil that has been subjected to hydrogenation treatment after polymerizing alpha olefin) are often used in the lubricating oil composition. These base oils are poorly biodegradable and have a large environmental load. For this reason, attempts have been made to use oils having excellent biodegradability such as vegetable oils such as rapeseed oil and ester oils such as ester synthetic oils as the base oil (lubricant base oil) of the lubricating oil composition.
For example, a synthetic ester synthesized by pentaerythritol and an acid component obtained by mixing a linear saturated monocarboxylic acid component having 6 to 14 carbon atoms and an α-branched saturated monocarboxylic acid component having 6 to 10 carbon atoms in a specific ratio. Synthetic lubricating base oils have been proposed (for example, Patent Document 1).
A lubricating oil composition containing a specific fatty acid ester as a main component has been proposed (for example, Patent Document 2).
Or the lubricating oil for bearings containing specific aliphatic carboxylic acid monoester, kinematic viscosity 5-15 mm < ² > / s, and viscosity index 100 or more is proposed (for example, patent document 3).

Lubricating oil compositions are used in a wide range of applications such as bearings, hydraulic operating parts and metal processing for the purpose of reducing friction and wear, transferring energy, and cooling heat. The friction reducing effect by the lubricating oil composition depends on the thickness of the oil film, and a sufficient friction reducing effect can be obtained by forming an oil film having an appropriate thickness for each application on the solid surface. If the viscosity of the lubricating oil composition changes greatly depending on the temperature used, the thickness of the oil film changes accordingly, and the friction reducing effect cannot be obtained stably. For example, if the viscosity of the lubricating oil composition becomes too high at low temperatures, a uniform oil film cannot be formed. On the other hand, if the viscosity of the lubricating oil composition becomes too low at a high temperature, the oil film becomes thin and the friction reducing effect decreases.
Thus, in order to stably obtain the friction reducing effect, the lubricating oil composition needs to have a low kinematic viscosity (low kinematic viscosity) and a small viscosity change with respect to a temperature change. The degree of viscosity change with respect to temperature change is represented by a viscosity index, and the higher the viscosity index (higher viscosity index), the smaller the degree of viscosity change with respect to temperature change.

Although ester oil has a higher viscosity index than mineral oil or PAO, it does not satisfy the functions required for various lubricating oil compositions.
For this reason, in order to enhance various functions, the lubricating oil composition has various viscosity esters such as polymethacrylate polymer compounds or polyolefin polymer compounds or pour point depressants, and various phosphate esters such as zinc dialkyldithiophosphate. Friction reducing agents represented by: oily agents such as lauryl alcohol and oleic acid, extreme pressure agents such as zinc dialkyldithiophosphates, sulfurized olefins and chlorinated paraffins, 2.6-di-t-butylparacresol, dioctylphenylamine Antioxidants such as triphenyl phosphite, corrosion inhibitors such as isostearate, sorbitan oleate and alkenyl succinic acid, antifoaming agents such as silicone, metal deactivators such as benzotriazole, thiadiazole and dithiocarbamate, succinate Antirust agent such as acid, calcium sulfonate, Al Le earth metal sulfonate, additives such as a detergent-dispersant, such as polyalkenyl succinimide is blended.
Furthermore, package products in which a plurality of additives are combined are used for various applications such as engine oil and hydraulic fluid.

Although the above-mentioned additives and packaged products (hereinafter sometimes referred to as “lubricating oil additives” in general) are essential raw materials for commercialization of lubricating oil compositions, depending on the type of ester oil, lubrication may occur. There exists a problem that it cannot melt | dissolve so that an oil additive can exhibit the addition effect.
In order to solve these problems, for example, an invention has been proposed in which the solubility of the additive is improved by using trimethylolpropane (TMP) tricaprylate or a polymer of this with 1-dodecene (for example, Patent Document 4).

JP-A-7-224289 JP 2002-206094 A JP 2008-179773 A JP-A-1-252699

However, although the inventions of Patent Documents 1 to 3 are superior in biodegradability compared to mineral oil and PAO, they are not satisfactory in terms of coexistence of low kinematic viscosity and high viscosity index, and are soluble in lubricating oil additives. Was insufficient.
The invention of Patent Document 4 has a problem that the manufacturing process is complicated and the kinematic viscosity increases.
Accordingly, it is an object of the present invention to provide a lubricating base oil that can dissolve a lubricating oil additive satisfactorily and can achieve both a low kinematic viscosity and a high viscosity index at a higher level.

  As a result of intensive studies, the present inventors have formulated a lubricating oil additive by blending a specific fatty acid polyoxyalkylene alkyl ether, a specific fatty acid alkyl ester, and a specific fatty acid polyol ester in a specific amount. The present inventors have found that it can be dissolved satisfactorily and can achieve both a low kinematic viscosity and a high viscosity index.

（（ＩＶ）式中、Ｒ^７は炭素数１〜６の一価の炭化水素基又はメチロール基を表す。）

（（１）式中、ｎ_ＭＡＸは全体のアルキレンオキシド付加体中に質量基準で最も多く存在するアルキレンオキシド付加体のアルキレンオキシドの付加モル数を示す。ｉはアルキレンオキシドの付加モル数を示す。Ｙｉは全体のアルキレンオキシド付加体中に存在するアルキレンオキシドの付加モル数がｉであるアルキレンオキシド付加体の割合（質量％）を示す。） That is, the lubricating base oil of the present invention is represented by the following general formula (I), and the fatty acid polyoxyalkylene alkyl ether (A) 10 represented by the following formula (1) has a narrow ratio of 55 to 80%. 70 mass%, fatty acid alkyl ester (B) represented by the following general formula (II) 5 to 60 mass%, fatty acid or fatty acid alkyl ester represented by the following general formula (III) and the following general formula (IV) It contains the fatty acid polyol ester (C) 5-60 mass% obtained by making it react with the polyhydric alcohol represented by these, It is characterized by the above-mentioned.
R ¹ —CO—Q _n —OR ² (I)
(In the formula (I), R ¹ represents a linear monovalent hydrocarbon group having 7 to 19 carbon atoms, R ² represents a monovalent hydrocarbon group having 1 to 8 carbon atoms, and Q represents carbon. The oxyalkylene group of the number 2 to 4 is represented, and n is a number of 3 to 9 representing the average number of added moles of alkylene oxide.)
R ³ —COO—R ⁴ (II)
(In the formula (II), R ³ represents a linear monovalent hydrocarbon group having 7 to 19 carbon atoms, and R ⁴ represents a monovalent hydrocarbon group having 3 to 8 carbon atoms.)
R ⁵ —COO—R ⁶ (III)
(In the formula (III), R ⁵ represents a linear or branched monovalent saturated hydrocarbon group having 7 to 9 carbon atoms or a monovalent unsaturated hydrocarbon group having 17 to 19 carbon atoms; ⁶ represents hydrogen or a monovalent hydrocarbon group having 1 to 8 carbon atoms.)

(In the formula (IV), R ⁷ represents a monovalent hydrocarbon group or methylol group having 1 to 6 carbon atoms.)

(In formula (1), n _MAX represents the number of moles of alkylene oxide adduct of the alkylene oxide adduct most present on a mass basis in the whole alkylene oxide adduct, and i represents the number of moles of alkylene oxide added. Yi represents the proportion (% by mass) of the alkylene oxide adduct having an added mole number of alkylene oxide i present in the entire alkylene oxide adduct.

  According to the lubricating base oil of the present invention, the lubricating oil additive can be dissolved well, and a low kinematic viscosity and a high viscosity index can be achieved at a higher level.

(Lubricant base oil)
The lubricating base oil of the present invention contains a fatty acid polyoxyalkylene alkyl ether (A), a fatty acid alkyl ester (B), and a fatty acid polyol ester (C).
The lubricating base oil is the main component of the lubricating oil composition. The content of the lubricating base oil in the lubricating oil composition is, for example, preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, and particularly preferably 80% by mass or more.

<Fatty acid polyoxyalkylene alkyl ether (A)>
The fatty acid polyoxyalkylene alkyl ether (A) (hereinafter sometimes referred to as component (A)) is represented by the following formula (I).

R ¹ —CO—Q _n —OR ² (I)

(In the formula (I), R ¹ represents a linear monovalent hydrocarbon group having 7 to 19 carbon atoms, R ² represents a monovalent hydrocarbon group having 1 to 8 carbon atoms, and Q represents carbon. The oxyalkylene group of the number 2 to 4 is represented, and n is a number of 3 to 9 representing the average number of added moles of alkylene oxide.)

R ¹ may be a saturated hydrocarbon group or an unsaturated hydrocarbon group as long as it is linear and monovalent, but an unsaturated hydrocarbon group is preferred. If R ¹ is an unsaturated hydrocarbon group, the ability to dissolve the lubricant additive (additive solubility) and the viscosity index can be increased, and the pour point can be lowered. Incidentally, (A) component may be a mixture of those ones with R ¹ in which R ¹ is a saturated hydrocarbon group is an unsaturated hydrocarbon group.

R ¹ has 7 to 19 carbon atoms. If it is at least the above lower limit value, the solubility of the additive and the viscosity index can be increased.
Preferred number of carbon atoms in R ^1, if R ¹ is a saturated hydrocarbon radical, additive solubility, heat resistance, preferably 15 to 19 from the viewpoint of enhancing the viscosity index, from the viewpoint of lowering the kinematic viscosity and pour point Is preferably 7-11. Further, if ^{R 1} is an unsaturated hydrocarbon group, additive solubility, heat resistance, preferably 15 to 19 from the viewpoint of enhancing the viscosity index, 7-11 or from the viewpoint of lowering the pour point 17-19 Is preferred. In addition, (A) component may be a mixture of different carbon numbers for R ¹ .
R ¹ is preferably an unsaturated hydrocarbon group having 17 to 19 carbon atoms from the viewpoint of increasing the solubility of the additive, heat resistance, viscosity index, and lowering the pour point.

The fatty acid corresponding to the fatty acid part (R ¹ -CO) of the component (A) includes caprylic acid, capric acid, lauric acid, myristic acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid Linolenic acid, elaidic acid, arachidic acid, arachidonic acid, arachidic acid, palm-derived C18 mixed fatty acid (for example, C16 / C18: 0 / C18: 1 / C18: 2 = 3/10/70/17 mixed fatty acid. , “C18: X” represents the number of unsaturated bonds.), Palm kernel derived mixed fatty acid, palm derived mixed fatty acid, soybean derived C18 mixed fatty acid, rapeseed derived C18 mixed fatty acid, corn derived mixed fatty acid, safflower Examples include derived mixed fatty acids.

R ² may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. R ² may be linear, branched or cyclic. A branched chain is preferable from the viewpoint of lowering the pour point.

R ² has 1 to 8 carbon atoms. If it is more than the said lower limit, it is excellent in additive solubility, and if it is below the said upper limit, kinematic viscosity can be made low. Preferred number of carbon atoms in R ^2, if R ² is a linear, 1 is preferable from the viewpoint of lowering the kinematic viscosity and pour point, if R ² is branched, 3 from the viewpoint of lowering the pour point ~ 8 is preferred. From the viewpoint of easy acquisition and production of the component (A), R ² preferably has 1 carbon atom (methyl group).

 Q is an oxyalkylene group having 2 to 4 carbon atoms. The carbon number of Q is preferably 3 to 4 from the viewpoint of lowering the pour point, and preferably 2 to 3 from the viewpoint of lowering the kinematic viscosity. From the viewpoint of lowering the pour point and kinematic viscosity, Q has 3 carbon atoms, that is, Q is preferably an oxypropylene group.

 n is a number of 3 to 9 representing the average number of added moles of alkylene oxide, 4 to 9 is preferable from the viewpoint of increasing heat resistance and viscosity index, and 3 to 7 is preferable from the viewpoint of reducing kinematic viscosity, From the viewpoint of achieving both a low kinematic viscosity and a high viscosity index, 4 to 7 is preferable.

As the component (A), R ¹ is an unsaturated hydrocarbon group having 17 to 19 carbon atoms, R ² is a hydrocarbon group having 1 carbon atom (methyl group), Q is an oxypropylene group, and n is 4 to 7 Those are preferred.

The component (A) has a narrow rate of 55 to 80% represented by the following formula (1), preferably a narrow rate of 55 to 75%, and more preferably 55 to 70%. When the narrow rate is less than the lower limit, additive solubility and heat resistance are lowered. In addition, if the narrow rate is less than the lower limit, odor may be generated, the flash point may be lowered, or the pour point may be increased. If the narrow ratio is more than the above upper limit, the additive solubility and the viscosity index become insufficient, and the heat resistance may be lowered.
In addition, when using 2 or more types of (A) component together, the narrow rate of (A) component is the narrow rate in each (A) component, and is not the narrow rate in the mixture of 2 or more types (A) component. .
For example, when the component (A) is obtained by an esterification method or a transesterification method to be described later, the glycol ether as a raw material is distilled to separate a low boiling point component and a high boiling point component to obtain a glycol ether having a desired narrow ratio. The narrow ratio of the component (A) may be adjusted by using it for esterification or transesterification.
In addition, when the component (A) is obtained by the direct reaction method described later, a catalyst obtained by changing the type of catalyst or calcining alumina hydroxide / magnesium and a basic substance such as NaOH or KOH are used in combination. The narrow ratio of the component (A) can be adjusted.

(1) In formula, _nMAX shows the addition mole number of the alkylene oxide of the alkylene oxide adduct which exists most on the basis of mass in the whole alkylene oxide adduct. i represents the number of added moles of alkylene oxide. Yi represents the proportion (% by mass) of the alkylene oxide adduct having an added mole number of alkylene oxide i present in the entire alkylene oxide adduct (ie, component (A)).

As for n _MAX , when there are two types of adducts having the largest number of alkylene oxides on a mass basis, those having one added mole number of alkylene oxide than those having a larger number of added moles of alkylene oxide, Compared with one having a smaller number of added moles of alkylene oxide than one having a smaller number of added moles of oxide, the number of added moles of alkylene oxide of the fatty acid polyoxyalkylene alkyl ether on the side having the larger amount is defined as n _MAX . . For example, if the fatty acid polyoxyalkylene alkyl ethers of i = 4 and i = 5 are equal in amount and are the most on a mass basis, respectively, the fatty acid polyoxyalkylene alkyl ether of i = 3 and the fatty acid polyoxyalkylene alkyl of i = 6 Oxyalkylene alkyl ethers are compared, and if there are more fatty acid polyoxyalkylene alkyl ethers with i = 3, then n _MAX = 4. On the other hand, if there are more fatty acid polyoxyalkylene alkyl ethers with i = 6, n _MAX = 5.
In addition, although n in (A) component is the average addition mole number of alkylene oxide, (A) component has a wide addition mole number distribution, and even when n = 3, in (A) component, Contains a compound having 1 or 2 alkylene oxide addition moles. In addition, when n = 9, a high addition mole having an alkylene oxide addition mole number of 10, 11, 12, or the like is contained. The narrow ratio is calculated after the content (mass%) of these structures is included. That is, i is a number that can take an integer of 1 or more.

  The narrow ratio is calculated by the above formula (1) by measuring the content (mass%) of each component (A) for each added mole number of alkylene oxide with respect to the total amount of the component (A) by gas chromatographic analysis. Is required.

As the component (A), for example, polyoxypropylene lauric acid methyl ether (M12-7PO, propylene oxide 7-mol adduct, synthetic product obtained by transesterification, hereinafter sometimes referred to as component (a1)), polyoxypropylene C18 mixed fatty acid methyl ether (M182-7PO, propylene oxide 7-mole adduct, synthetic product by transesterification, hereinafter referred to as component (a2)), polyoxyalkylene C18 mixed fatty acid methyl ether (M182-5EO-3PO) , An adduct of 5 mol of ethylene oxide and 3 mol of propylene oxide, a synthetic product by transesterification, a trade name: Leo Fat OC-0503M (manufactured by Lion Corporation, hereinafter, also referred to as component (a3)), polyoxypropylene C18 mixed fatty acid methyl ether (M182-5PO, propylene oxide 5 mol adduct, synthetic product by direct reaction method, hereinafter referred to as component (a4)), polyoxypropylene C18 mixed fatty acid methyl ether (M182-7PO, propylene oxide 7 mol adduct) , Synthetic product by direct reaction method, hereinafter referred to as component (a5)), polyoxypropylene C18 mixed fatty acid methyl ether (M182-3PO, propylene oxide 3 mol adduct, synthetic product by direct reaction method, hereinafter ( (It may be called a6) component.) The additive solubility of the above-mentioned components (a1) to (a6) is (a2) to (a6) component> (a1) component.
Among the components (A) described above, the component (a2), the component (a3), the component (a4), and the component (a6) are preferable from the viewpoint of achieving both a low kinematic viscosity and a high viscosity index, and further excellent heat resistance. (A2) component, (a3) component, and (a4) component are more preferable at the point.

 Content of (A) component in lubricating base oil is 10-70 mass%, and 10-50 mass% is more preferable. If it is less than the said lower limit, a viscosity index cannot be made high enough and there exists a possibility that heat resistance may fall. Above the upper limit, sufficient additive solubility cannot be obtained.

≪ (A) Component Production Method≫
(A) As a manufacturing method of a component, for example, the method of esterifying fatty acid or fatty acid ester with glycol ether (esterification method), the method of transesterifying fatty acid ester and glycol ether (transesterification method), and fatty acid ester Examples include a method of directly adding an alkylene oxide (direct reaction method), and the direct reaction method is preferable among them. In the esterification method and the transesterification method, the component (A) having a small number of added moles is easily removed in order to remove unreacted raw materials and the like. For this reason, the (A) component obtained by the esterification method or the transesterification method tends to have a high narrow rate and a low viscosity index. On the other hand, the direct reaction method can easily produce the component (A) having a low narrow rate, has a simple process, and is suitable for industrial production.
Examples of the direct reaction method include the method described in JP-A-8-169861.

<Fatty acid alkyl ester (B)>
The fatty acid alkyl ester (B) (hereinafter sometimes referred to as the component (B)) is represented by the following formula (II). Lubricant base oil contains (B) component, and additive solubility improves.

R ³ —COO—R ⁴ (II)

(In the formula (II), R ³ represents a linear monovalent hydrocarbon group having 7 to 19 carbon atoms, and R ⁴ represents a monovalent hydrocarbon group having 3 to 8 carbon atoms.)

R ³ may be a saturated hydrocarbon group, an unsaturated hydrocarbon group, or a mixture thereof as long as it is linear and monovalent. Among these, a saturated hydrocarbon group is preferable from the viewpoint of heat resistance.

R ³ has 7 to 19 carbon atoms. If it is less than the lower limit, the additive solubility and viscosity index cannot be sufficiently increased, and if it exceeds the upper limit, the pour point becomes high and the kinematic viscosity cannot be sufficiently lowered.
Preferred number of carbon atoms in R ^3, if R ³ is a saturated hydrocarbon radical, additive solubility, preferably 9 to 19 from the viewpoint of enhancing the viscosity index, also from the viewpoint of lowering the pour point 7-11 Is preferred. Moreover, if R < ³ > is an unsaturated hydrocarbon group, 17-19 are preferable from a viewpoint of making a pour point low, raising a viscosity index.
The number of carbon atoms in R ³ is more preferably 9 to 11 from the viewpoint of increasing the additive solubility, the viscosity index, and lowering the kinematic viscosity and pour point.

As the fatty acid corresponding to the fatty acid part (R ³ —CO) of the component (B), caprylic acid, capric acid, lauric acid, myristic acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid Linolenic acid, elaidic acid, arachidic acid, arachidonic acid, arachidic acid, palm derived C18 mixed fatty acid, palm kernel derived mixed fatty acid, palm derived mixed fatty acid, soybean derived C18 mixed fatty acid, rapeseed derived C18 mixed fatty acid, corn derived mixed fatty acid, Examples include safflower-derived mixed fatty acids.

R ⁴ may be linear, branched or cyclic as long as it is monovalent. Of these, a branched chain is preferred from the viewpoint of lowering the pour point.
R ⁴ has 3 to 8 carbon atoms, preferably 4 to 8 carbon atoms. If it is in the said range, additive solubility can be improved.
R ⁴ is preferably a branched chain having 4 to 8 carbon atoms from the viewpoint of further improving the solubility of the additive and lowering the pour point.

As the component (B), for example, R ³ is a hydrocarbon group having 7 to 11 carbon atoms or an unsaturated hydrocarbon group having 17 carbon atoms, and R ⁴ is a branched monovalent hydrocarbon having 4 to 8 carbon atoms. Isobutyl caprylate, t-butyl caprylate, 2-ethylhexyl caprylate, isobutyl caprate, t-butyl caprate, 2-ethylhexyl caprate, isobutyl laurate, t-butyl laurate, 2-ethylhexyl laurate , Isobutyl oleate, t-butyl oleate, oleic acid-2-ethylhexyl, palm-derived C18 mixed fatty acid isobutyl, palm-derived C18 mixed fatty acid t-butyl, palm-derived C18 mixed fatty acid-2 ethylhexyl, among them, caprylic acid-2 Ethylhexyl, lauric acid-2-ethylhexyl, oleic acid-2 ethylhexyl Sill, palm-derived C18 mixed fatty -2-ethylhexyl is preferable.

 Content of (B) component in lubricating base oil is 5-60 mass%, 20-60 mass% is preferable and 20-50 mass% is more preferable. If it is less than the lower limit, the solubility of the additive becomes insufficient, and if it exceeds the upper limit, the kinematic viscosity may be too low or sufficient heat resistance may not be obtained.

<Fatty acid polyol ester (C)>
The fatty acid polyol ester (C) (hereinafter sometimes referred to as the component (C)) is a fatty acid or a fatty acid alkyl ester represented by the following general formula (III) (hereinafter sometimes collectively referred to as the component (c1)), It is obtained by reacting with a polyhydric alcohol represented by the following general formula (IV) (hereinafter sometimes referred to as component (c2)). (C) By containing a component, additive solubility and heat resistance can be improved.

R ⁵ —COO—R ⁶ (III)

(In the formula (III), R ⁵ represents a linear or branched monovalent saturated hydrocarbon group having 7 to 9 carbon atoms or a monovalent unsaturated hydrocarbon group having 17 to 19 carbon atoms; ⁶ represents hydrogen or a monovalent hydrocarbon group having 1 to 8 carbon atoms.)

(In the formula (IV), R ⁷ represents a monovalent hydrocarbon group or methylol group having 1 to 6 carbon atoms.)

R ⁵ is a monovalent saturated hydrocarbon group having 7 to 9 carbon atoms or a monovalent unsaturated hydrocarbon group having 17 to 19 carbon atoms. From the viewpoint of lowering the kinematic viscosity, R ⁵ is saturated with 7 to 9 carbon atoms. A hydrocarbon group is preferable, and a saturated hydrocarbon group having 9 carbon atoms or an unsaturated hydrocarbon group having 17 to 19 carbon atoms is preferable from the viewpoint of increasing additive solubility and viscosity index. Of these, a saturated hydrocarbon group having 9 carbon atoms is more preferable from the viewpoint of lowering the kinematic viscosity and increasing the solubility of the additive and the viscosity index. Further, when R ⁵ is a saturated hydrocarbon group having 9 carbon atoms, it is easy to obtain and manufacture the component (c1).
When R ⁵ is a saturated hydrocarbon group having 7 to 9 carbon atoms, the hydrocarbon group may be either linear or branched, and in particular, linear from the viewpoint of obtaining a high viscosity index. Is preferred.
When R ⁵ is an unsaturated hydrocarbon group having 17 to 19 carbon atoms, the hydrocarbon group may be linear, branched or cyclic, and above all, from the viewpoint of obtaining a high viscosity index. A straight chain is preferred.

R ⁶ is hydrogen or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 8 carbon atoms. After the reaction, R ⁶ is removed as water or alcohol by a purification treatment such as distillation under reduced pressure, and therefore may have any structure. However, R ⁶ is particularly preferably hydrogen or a methyl group having 1 carbon atom because it is easily available and the component (C) can be easily obtained and manufactured.

 As component (c1), caprylic acid, capric acid, oleic acid, linoleic acid, linolenic acid, elaidic acid, arachidic acid, arachidonic acid, palm-derived C18 mixed fatty acid, palm kernel-derived mixed fatty acid, palm-derived mixed fatty acid, soybean-derived Examples include C18 mixed fatty acids, rapeseed-derived C18 mixed fatty acids, corn-derived mixed fatty acids, safflower-derived mixed fatty acids and the like, and their alkyl esters (fatty acid alkyl esters). Among them, caprylic acid, capric acid, oleic acid, linoleic acid, linolenic acid or palm-derived alkyl ester of C18 mixed fatty acid is preferable, and methyl ester of the fatty acid is more preferable.

R ⁷ is a hydrocarbon group having 1 to 6 carbon atoms or a methylol group, and from the viewpoint of improving additive solubility and heat resistance, a methylol group or a hydrocarbon group having 1 to 6 carbon atoms is preferable, and the additive solubility is high. From the viewpoint of increasing heat resistance and reducing kinematic viscosity, a hydrocarbon group having 1 to 3 carbon atoms is more preferable.

When R ⁷ is a hydrocarbon group having 1 to 6 carbon atoms, R ⁷ may be linear, branched or cyclic, but is preferably linear from the viewpoint of increasing the viscosity index.
R ⁷ may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group, but a saturated hydrocarbon group is preferable from the viewpoint of availability.

  Examples of the component (C) include trimethylol alkane polyol ester represented by the following general formula (i), pentaerythritol polyol ester represented by the following general formula (ii), and the like.

(In the formula (i), R ⁵ is the same as R ⁵ in the formula (III), and all may be the same or different from each other. (I) In the formula, m is And is an integer of 1 to 6. (ii) In the formula, R ⁵ is the same as R ⁵ in the formula (III), and all may be the same or different from each other.

  Examples of the trimethylolalkane polyol ester include trimethylolpropane tricaprylate, trimethylolpropane tricaplate (manufactured by Lion Corporation, Rubinol F-308N, F-310N, etc.), trimethylolpropane trioleate (manufactured by NOF Corporation, Unistar). H-381R and the like), and pentaerythritol polyol ester includes pentaerythritol tetraoleate (manufactured by NOF Corporation, Unistar H-481R). Among them, trimethylolalkane polyol ester is preferable, and trimethylolpropane tricaplate is particularly preferable from the viewpoint of improving additive solubility and achieving both low kinematic viscosity and high viscosity index in higher dimensions.

 Content of (C) component in lubricating base oil is 5-60 mass%, 10-50 mass% is preferable and 10-40 mass% is more preferable. If it is less than the lower limit, the additive solubility becomes insufficient and the heat resistance may be lowered. If it exceeds the above upper limit, the additive solubility becomes insufficient, and the content of other components (particularly the component (A)) is small, making it difficult to achieve both low kinematic viscosity and high viscosity index. .

≪ (C) Component manufacturing method≫
As a method for producing the component (C), for example, the fatty acid (c1) and the component (c2) are heated to an arbitrary temperature in the presence of a catalyst, and the component (c1) is esterified with the component (c2). (Esterification step) (esterification method).

 The compounding ratio of the component (c1) and the component (c2) in the esterification step is, for example, when the component (c2) is triol, the molar ratio represented by (c1) / (c2) is 3-6. Is preferred.

Examples of the catalyst used in the esterification step include acid catalysts such as sulfuric acid, p-toluenesulfonic acid (p-TS), and benzenesulfonic acid (BS), ZrO ₂ , TiO ₂ , SiO ₂ , PO ₄ , and Al ₂ O. ₃ and inorganic oxide catalysts such as ZnO.
The amount of the catalyst used in the esterification step can be determined in consideration of the type of the catalyst, for example, 0.01 to 5.0 parts by mass with respect to 100 parts by mass in total of the (c1) component and the (c2) component. It is said.
The heating temperature in the esterification step is, for example, 150 to 260 ° C.

After the esterification step, a purification step can be provided as necessary.
The purification step is a step of removing unreacted component (c1), component (c2), by-product water and catalyst. A conventionally well-known purification method can be used for a refinement | purification process, For example, the method of filter-separating using filter aids, such as calcination diatomaceous earth, centrifugation, vacuum distillation, etc. are mentioned.

 Moreover, as a manufacturing method of (C) component, for example, the fatty acid alkyl ester which is (c1) component and (c2) component are heated in presence of a catalyst, (c1) component and (c2) component are made. Examples include transesterification (transesterification step) (transesterification method).

 The compounding ratio of the component (c1) and the component (c2) in the transesterification step is the same as the compounding ratio of the component (c1) and the component (c2) in the esterification step.

Examples of the catalyst used in the transesterification step include hydroxides such as lithium, cesium, sodium, potassium, magnesium, barium and calcium, basic catalysts such as hydrogen carbonate, carbonate, sodium methoxide and potassium methoxide, Examples include titanium-based tetraisopropyl titanate, tetra n-butyl titanate, tetraethanolamine titanate, and tetrastearyl titanate.
The amount of the catalyst used in the transesterification step can be determined in consideration of the type of the catalyst, for example, 0.01 to 5.0 parts by mass with respect to 100 parts by mass in total of the component (c1) and the component (c2). It is said.
The heating temperature in the transesterification step is, for example, 150 to 260 ° C.

After the transesterification step, a purification step can be provided as necessary.
The purification step is a step of removing unreacted (c1) component, (c2) component, by-product alcohol and catalyst.
The purification step provided after the transesterification step is the same as the purification step provided after the esterification step.

<Optional component>
Lubricating oil base oil can contain an arbitrary component as needed in the range which does not impair the effect of this invention. Examples of the optional component include mineral base oils, hydrocarbon oils such as PAO and isobutene, and lubricant base oils (arbitrary oil base oils) other than the components (A) to (C). By containing an optional base oil, various properties such as kinematic viscosity, viscosity index, heat resistance, and pour point can be adjusted.
The content of the optional base oil in the lubricating base oil is preferably 1 to 50% by mass, and more preferably 5 to 20% by mass from the viewpoint of maintaining a high viscosity index.

<Physical properties of lubricating base oil>
Kinematic viscosity at 40 ° C. of the lubricating base oil is preferably 7~30mm ² / s, more preferably 8~22mm ² / s, more preferably 9.8~15mm ² / s. If the kinematic viscosity at 40 ° C. is equal to or higher than the above lower limit value, it is easy to suppress the kinematic viscosity from decreasing and the oil film from becoming too thin at high temperatures, and it is easy to suppress an increase in frictional force or wear due to the oil film breakage. If the kinematic viscosity at 40 ° C. is equal to or lower than the above upper limit, energy is saved with a low friction loss (low torque), and it is economical to take out the lubricating base oil.

Kinematic viscosity at 100 ° C. of the lubricating base oils of the present invention is preferably from 2 to 10 mm ² / s, more preferably from 2 to 8 mm ² / s, more preferably 2 to 6 mm ² / s. If the kinematic viscosity at 100 ° C. is 2 mm ² / s or more, it is easy to suppress the oil film from becoming too thin. When the kinematic viscosity at 100 ° C. is 10 mm ² / s or less, energy is saved with a low friction loss (low torque), and it is economical to take out the lubricating base oil.

 The viscosity index of the lubricating base oil of the present invention is preferably 150 or more, more preferably 160 or more, and even more preferably 170 or more. If the viscosity index is equal to or greater than the above lower limit value, the change in kinematic viscosity due to a temperature change is small, and a high friction reduction effect is easily obtained stably over a wide temperature range. Moreover, the viscosity index of the lubricating oil composition when the lubricating base oil of the present invention is mixed with another base oil is also improved. Further, when a viscosity index improver is added, the amount of addition is reduced, and therefore the degree of viscosity reduction due to shearing is reduced.

 The pour point of the lubricating base oil is preferably −20 ° C. or lower, more preferably −30 ° C. or lower, and even more preferably −35 ° C. or lower, from the viewpoint of ensuring handling in a wide range of usage environments such as winter and high latitude areas. .

<Manufacturing method>
The method for producing the lubricating base oil is not particularly limited, and examples thereof include a method of stirring and mixing the components (A) to (C) under an arbitrary temperature condition. Examples of the apparatus for stirring and mixing include conventionally known mixing tanks with stirring blades, purification tanks with stirring blades equipped with a device that can be dehydrated by decompression, and the like.

 The lubricating base oil of the present invention is suitable for applications requiring a low kinematic viscosity and a high viscosity index. Specifically, automotive engine oil, marine engine oil, construction machine engine oil, agricultural machinery engine oil, grease base oil, refrigeration oil, cutting, grinding, rolling, pressing metal processing oil, bearing oil, Transmission oil, differential oil, torque converter oil, hydraulic fluid, etc., more preferably, the temperature at the time of initial operation of the lubrication part is near room temperature, and the temperature rises during use. It is mainly in the range of 0 to 130 ° C. and is suitable for use in lubricated parts that require low kinematic viscosity. As such an application, for example, it is preferable to be used as a base oil of any one of hydraulic hydraulic oil, transmission oil, metalworking oil, grease oil or bearing oil, and above all, it is used as a base oil for hydraulic hydraulic oil. Is more preferable, and it is particularly preferably used as a base oil of a hydraulic fluid for a shock absorber such as a vehicle damper or a shock absorber or oil sealed in a vibration control device.

 In addition to the lubricating base oil of the present invention, a lubricating oil composition such as hydraulic fluid, transmission oil, metalworking oil, grease oil, bearing oil, etc., if necessary, hydrocarbon oil such as mineral oil, PAO, isobutene, etc. Polyol esters other than the components (A) to (C), complex esters, fatty acid alkyl esters, other lubricating base oils such as rapeseed oil, rice bran oil and soybean oil can be used in combination.

In addition, as necessary, the lubricating oil composition may include an antioxidant, an extreme pressure agent, a friction modifier, a metal deactivator, a fluid antistatic agent, a viscosity index improver, a pour point depressant, and a cleaning dispersant. In addition, a conventionally known additive such as a molecular restoration agent, an emulsifier, or a package product obtained by combining a plurality of these can be added. Examples of the viscosity index improver include methacrylate polymers (manufactured by Sanyo Kasei Kogyo Co., Ltd., trade names “Aclude 136”, “Sun-Lube 1703”) and the like. Moreover, as a lubricating oil additive used for a natural gas engine, a marine diesel engine, etc., HiTEC 638 (ashless dispersant, manufactured by Afton chemical (USA)) and the like can be mentioned. Examples of the package product include HiTEC 9325G (additive package, manufactured by Afton chemical (USA)), which is a general-purpose grade product for engine oil packages.
Since the lubricating base oil of the present invention can dissolve these lubricating oil additives satisfactorily, the lubricating oil additive can sufficiently function.

  The content of the lubricating oil additive in the lubricating oil composition can be determined in consideration of functions required for the lubricating oil composition, and is preferably 0.01 to 20% by mass, for example. If the amount is less than the lower limit, the additive effect of the lubricating oil additive may not be obtained. If the amount exceeds the upper limit, the content of other components (particularly the components (A) to (C)) decreases. It may be difficult to achieve both a low kinematic viscosity and a high viscosity index.

Since the lubricating base oil described above contains a specific amount of the components (A) to (C), the lubricating oil additive can be dissolved well, and a low kinematic viscosity and a high viscosity index can be achieved at a higher level.
And since low kinematic viscosity and high viscosity index are compatible in a high dimension, it is suitable for the base oil of the hydraulic fluid of various shock absorbers.

EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated in detail, this invention is not limited by the following description.
(Raw materials used)
<(A) component: fatty acid polyoxyalkylene alkyl ether (A)>
As the component (A), the following A-1 to A-6 having the specifications shown in Table 1 were used.
A-1: Polyoxypropylene lauric acid methyl ether (M12-7PO, propylene oxide 7 mol adduct, produced in Production Example 1 described later)
A-2: Polyoxypropylene C18 mixed fatty acid methyl ether (M182-7PO, propylene oxide 7-mol adduct, produced in Production Example 2 described later)
A-3: Polyoxyalkylene C18 mixed fatty acid methyl ether (M182-5EO-3PO, adduct of 5 mol of ethylene oxide and 3 mol of propylene oxide, trade name: Leo Fat OC-0503M, manufactured by Lion Corporation)
A-4: Polyoxypropylene C18 mixed fatty acid methyl ether (M182-5PO, propylene oxide 5 mol adduct, produced in Production Example 3 described later)
A-5: Polyoxypropylene C18 mixed fatty acid methyl ether (M182-7PO, propylene oxide 7 mol adduct, produced in Production Example 4 described later)
A-6: Polyoxypropylene C18 mixed fatty acid methyl ether (M182-3PO, propylene oxide 3 mol adduct, produced in Production Example 5 described later)

<(A ′) component: Comparative product of component (A)>
As the component (A ′), the following A′-1 and A′-2 having the specifications shown in Table 1 were used.
A′-1: Polyoxypropylene C18 mixed fatty acid methyl ether (M182-5PO, propylene oxide 5 mol adduct, produced in Production Example 6 described later)
A′-2: Polyoxypropylene C18 mixed fatty acid methyl ether (M182-5PO, propylene oxide 5 mol adduct, produced in Production Example 7 described later)

<(B) component: fatty acid alkyl ester (B)>
As the component (B), the following B-1 to B-4 having the specifications shown in Table 1 were used.
B-1: Oleic acid-2-ethylhexyl (C18: 1-2EH, trade name: Unistar MB-881, manufactured by NOF Corporation)
B-2: lauric acid-2-ethylhexyl (C12-2EH, trade name: Pastel 2H-12, manufactured by Lion Corporation)
B-3: Caprylic acid-2-ethylhexyl (C8-2EH, trade name: Pastel 2H-08, manufactured by Lion Corporation)
B-4: Isopropyl laurate (C12-isopropyl, produced in Production Example 8 described later)

<(B ′) component: Comparative product of component (B)>
The following B′-1 having the specifications shown in Table 1 was used as the component (B ′).
B′-1: Lauric acid methyl ester (M12, trade name: Pastel M12, manufactured by Lion Corporation)

<(C) component: fatty acid polyol ester (C)>
As the component (C), the following C-1 to C-4 having the specifications shown in Table 1 were used.
C-1: Trimethylolpropane tricaprylate (TMP-C8, trade name: Rubinol F-308N, manufactured by Lion Corporation)
C-2: Trimethylolpropane tricaplate (TMP-C10, trade name: Rubinol F-310N, manufactured by Lion Corporation)
C-3: Trimethylolpropane trioleate (TMP-C18: 1, trade name: Unistar H-382R, manufactured by NOF Corporation)
C-4: Pentaerythritol tetraoleate (Pentaerythritol-C18: 1, trade name: Unistar H-481R, manufactured by NOF Corporation)

<(C ′) component: Comparative product of component (C)>
The following C′-1 having the specifications shown in Table 1 was used as the component (C ′).
C′-1: Neopentylglycol-Dicaplate (Neopentylglycol-C10, produced in Production Example 9 described later)

(Evaluation method)
<Narrow rate>
The distribution measurement of the number of added moles of the alkylene oxide of each of the component (A) or the component (A ′) and the calculation of the narrow ratio were performed according to the following procedure.
A sample was prepared by dissolving 0.5 g of component (A) or component (A ′) in 10 g of acetone. 1 μL of this sample was injected into an apparatus having the following specifications, and the concentration (% by mass) of each alkylene oxide added in the component (A) or component (A ′) was measured. From the obtained concentration, the narrow ratio was calculated by the above-described equation (1).

≪Device specifications≫
Gas chromatogram: HP-5890 (manufactured by Hewlett-Packard Company)
Detector: FID
Column: Ultra2, φ0.25 mm × length 25 m, film thickness 0.1 μm

≪Analysis conditions≫
Injection: 320 ° C
Detector: 320 ° C
Temperature: 80 ° C. → 100 ° C. (Temperature increase rate: 5 ° C./min)
100 ° C. → 320 ° C. (temperature increase rate: 25 ° C./min), 20 min hold Carrier gas: He
Split ratio: 50 to 1
Split vent flow rate: 50 mL / min
Purge vent flow rate: 3.5 mL / min

<Calculation method of average added mole number>
The average added mole number of EO (ethylene oxide) and PO (propylene oxide) was calculated from the mass balance of the raw materials and the charge of alkylene oxide. However, when distillation was performed after the addition reaction of EO and PO, the average number of added moles was determined by the following ¹ H-NMR analysis.
30 mg of the obtained compound was dissolved in 4 mL of deuterated chloroform and measured with ¹ H-NMR (300 MHz, FT NMR SYSTEM JNM-LA300 manufactured by JEOL Ltd.). Chemical shift 0.87ppm (terminal methyl of fatty acid), 1.13 to 1.15ppm (side chain methyl of PO), 3.32 to 3.66ppm (PO methine, based on 7.30ppm of chemical shift of deuterated chloroform And methylene) and 3.52 to 3.71 ppm (methylene of EO).

<Kinematic viscosity>
The kinematic viscosity at 40 ° C. or 100 ° C. was measured according to JIS K2283.
The sample was collected in a Cannon Fenceke type kinematic viscosity tube, kept warm for 30 minutes or more in a thermostatic bath maintained at 40 ° C. or 100 ° C., and the time when the sample was allowed to flow down in the Cannon Fenceke type kinematic viscosity tube was measured. .

<Viscosity index>
The kinematic viscosity at 40 ° C. and 100 ° C. was calculated based on the following formula (2) and the following (3) based on the viscosity index according to JIS K2283. The calculated viscosity index was classified and evaluated according to the following evaluation criteria.

Viscosity index = (10 ^N −1) /0.00715+100 (2)
N = (logH−logU) / logY (3)

However, each symbol in the formulas (2) and (3) is as follows.
U: Kinematic viscosity of the sample at 40 ° C. (mm ² / s).
Y: Kinematic viscosity at 100 ° C. (mm ² / s) of the sample.
H: Kinematic viscosity at 40 ° C. (mm ² / s) of a petroleum product having a viscosity index of 100 having the same kinematic viscosity as the sample at 100 ° C. Read and quote the corresponding kinematic viscosity from the appendix of JIS K2283.
N: The number necessary to match Y to the ratio of H and U.

≪Evaluation criteria≫
A: Viscosity index is 170 or more.
○: The viscosity index is 150 or more and less than 170.
X: Viscosity index is less than 150.

<Pour point>
The pour point was measured according to JIS K2269.
−20 ° C. or lower was evaluated as “◯” (passed), and −20 ° C. or higher was determined as “x” (failed).

<Heat resistance>
The heat resistance was measured with a DRY-BLOCK-BATH apparatus (manufactured by ASONE Corporation, THB-2). 5 g of a sample was taken in a glass bottle (SV-30, NICHIDEN-RIKA GLASS CO, LTD.), And after reaching 130 ° C., the mass after holding for 72 hours was recorded. 4) It was obtained from the equation and used as an index of heat resistance. The obtained mass reduction rate was classified into the following evaluation criteria, and “◯” or more was regarded as acceptable.

 Mass reduction rate (mass%) = (mass before test−mass after test) ÷ mass before test × 100 (4)

≪Evaluation criteria≫
A: Mass reduction rate is less than 3% by mass.
○: The mass reduction rate is 3% by mass or more and less than 4% by mass.
(Triangle | delta): Mass reduction rate is 4 mass% or more and less than 5 mass%.
X: Mass reduction rate is 5 mass% or more.

<Additive solubility>
To 39.6 g of the lubricating base oil of each example, HiTEC 9325G (additive package, manufactured by Afton chemical (USA), hereinafter referred to as additive A) or HiTEC 638 (ashless dispersant, Afton chemical ( USA), hereinafter, additive B) 0.4 g was added and mixed by shaking to prepare a sample. From the easiness of dissolution of the lubricant additive and the appearance after shake mixing, the additive solubility was evaluated according to the following evaluation criteria. Additives A and B are both “O” or “◎” as overall evaluation “O” (pass), and additives A and / or B are “X” or “△” as overall evaluation “×” "(Fail).

≪Evaluation criteria≫
A: Easily and evenly dissolved at room temperature, and the appearance after standing at room temperature for 1 day is a transparent liquid.
○: When heated to 60 ° C., it dissolves uniformly, and the appearance after standing at room temperature for 1 day is a transparent liquid.
(Triangle | delta): It melt | dissolves uniformly when heated to 60 degreeC, and although transparent at 60 degreeC, precipitation or cloudiness will arise after standing at room temperature for 1 day.
X: Even if it heats to 60 degreeC, it does not melt | dissolve uniformly.

(Manufacture example 1) Preparation of A-1 According to the following procedures, A-1 was manufactured by transesterification with lauric acid methyl ester and glycol ether.
After performing nitrogen substitution in the 4 L autoclave twice, 388 g of methanol (manufactured by Junsei Chemical Co., Ltd.) and 8.9 g of 28% by mass sodium methoxide as a catalyst were charged. Thereafter, the temperature was raised to 90 ° C., and 2112 g of PO (corresponding to 3.0 mol per 1 mol of methanol) was gradually introduced to carry out PO addition reaction. The pressure when introducing PO was 0.48 MPa. The pressure decreased with the progress of the reaction, and the PO addition reaction was continued until 2 hours later and became constant at 0.39 MPa to obtain a primary intermediate A (methanol-3PO form).
Next, 1223 g of the primary intermediate A was charged into a 4 L autoclave, heated to 90 ° C., and then PO861 g (corresponding to 2.5 mol relative to 1 mol of the primary intermediate A) was gradually introduced to carry out the PO addition reaction. went. The pressure at the time of PO introduction was 0.49 MPa. Thereafter, the pressure was reduced with the progress of the reaction, and the PO addition reaction was continued until 2 hours later and became constant at 0.38 MPa. After cooling, Kyoward 600S and Kyoward 700SL (above, inorganic synthetic adsorbent, manufactured by Kyowa Chemical Industry Co., Ltd.) 20 g each (1% by mass with respect to the crude product) were added, and the mixture was stirred at 95 ° C. for 30 minutes for catalyst. The secondary intermediate A (methanol-5.5PO body) was obtained by performing solid-liquid separation by pressure filtration at 80 ° C. Further, a tertiary intermediate in which the low-boiling fraction having an addition mole number of PO of 0 to 3 is removed by raising the temperature from normal temperature to 180 ° C. while gradually reducing the pressure from normal pressure to 5 Torr (0.7 kPa). A (methanol-7PO body, distilled product) was obtained.
Thereafter, in a 5 L four-necked flask equipped with a stirring blade, 1097 g of tertiary intermediate A and methyl laurate (fatty acid methyl ester derived from palm oil-derived carbon number 12 fraction, trade name: Pastel M12, manufactured by Lion Corporation) 508 g ( The equivalent of 0.95 mol per mol of the intermediate intermediate) and 7.3 g of sodium hydrogen carbonate were added, and while stirring, the pressure was gradually reduced from normal pressure to 5 Torr (0.7 kPa) while the temperature was reduced from 60 ° C to 210 ° C. The temperature was raised to 0 ° C., and a transesterification reaction was performed until the amount of unreacted methyl laurate was 2% by mass or less to obtain a crude product. Then, 10 g each of Kyoward 500SH and Kyoward 700SL (both manufactured by Kyowa Chemical Industry Co., Ltd.) are added to 1000 g of the crude product and heated at 95 ° C. for 1 hour for adsorption. Processed. Further, 10 g of Hyflo Supercell (trade name, manufactured by Celite) (1% by mass with respect to the crude product) was added and dispersed uniformly, followed by pressure filtration at 80 ° C., so that the average added mole of PO A-1 (M12-7PO, R ¹ = C ₁₁ H ₂₃ , R ² = CH ₃ ) having 7 moles was obtained.

(Production Example 2) Production of A-2 In place of lauric acid methyl ester, methyl oleate (C18 mixed fatty acid methyl ester derived from palm oil-derived C18 fraction (C16 / C18: 0 / C18: 1 / C18 : 2 = 3/10/70/17), brand name: Pastel M182, manufactured by Lion Co., Ltd.) is used in an amount of 0.95 moles per mole of tertiary intermediate A1, and stepwise from normal pressure to 5 Torr (0.7 kPa). A-2 (M182-7PO, R ¹ = C ₁₇ H ₃₃ , R ² = CH ₃ ) was produced in the same manner as in Production Example 1 except that the temperature was raised from 60 ° C. to 260 ° C. while reducing the pressure.

(Production Example 3) Production of A-4 According to the following procedure, methyl oleate (C18 mixed fatty acid methyl ester derived from palm oil-derived C18 fraction (C16 / C18: 0 / C18: 1 / C18: 2 = 3/10/70/17), trade name: Pastel M182, manufactured by Lion Corporation) and propylene oxide were directly added to produce A-4.
Alumina hydroxide-magnesia (Kyoward 300SN, manufactured by Kyowa Chemical Industry Co., Ltd.) represented by 2.5MgO.Al ₂ O ₃ · nH ₂ O was calcined at 750 ° C. for 3 hours in a nitrogen stream, and calcined alumina hydroxide A magnesium (Al / Mg molar ratio = 0.44 / 0.56) catalyst was obtained. Into a 4 L autoclave, 908 g of pastel M182 (trade name, manufactured by Lion Corporation) and 7.2 g of calcined alumina hydroxide / magnesium catalyst were charged, and nitrogen substitution was performed. Subsequently, in order to remove the water | moisture content contained in a raw material, it heated up to 100 degreeC and dehydrated at 5 Torr (0.7 kPa) for 1 hour. After dehydration, the temperature was raised to 180 ° C., nitrogen was introduced to return the inside of the autoclave reaction vessel to normal pressure, and 885 g of propylene oxide (PO) (corresponding to 5 mol per 1 mol of methyl oleate) was gradually added. Into the container. Immediately after the introduction, the pressure of 0.34 MPa decreased with the progress of the reaction, and the PO addition reaction was continued until the pressure became constant at 0.29 MPa after 2 hours. To 1350 g of the obtained crude product, 20.25 g of Hyflo Supercell (manufactured by Celite: Diatomaceous Earth) (1.5% by mass with respect to the crude product) was added and dispersed uniformly, followed by pressure filtration at 80 ° C. , A-4 (M182-5PO, R ¹ = C ₁₇ H ₃₃ , R ² = CH ₃ ) was obtained.

(Production Example 4) Production of A-5 A-5 (M182-7PO, R ¹ = C ₁₇ H ₃₃ , R ² = CH ₃ ) in the same manner as in Production Example 3 except that the amount of PO introduced was 1239 g. Got.

(Production Example 5) Production of A-6 A-6 (M182-3PO, R ¹ = C ₁₇ H ₃₃ , R ² = CH ₃ ) in the same manner as in Production Example 3, except that the amount of PO introduced was 531 g. Got.

(Production Example 6) Production of A′-1 First, 1412 g of the primary intermediate A in Production Example 1 was charged into a 4 L autoclave, heated to 90 ° C., and further PO795 g (corresponding to 2 moles relative to 1 mole of the primary intermediate A). The PO addition reaction was carried out gradually. The pressure at the time of PO introduction was 0.49 MPa. The PO addition reaction was continued until the pressure decreased with the progress of the reaction and became constant at 0.38 MPa after 2 hours. Then, without performing distillation operation, Kyoward 600S and Kyoward 700SL (above, inorganic synthetic adsorbent, manufactured by Kyowa Chemical Industry Co., Ltd.) were added in an amount of 22 g (1% by mass relative to the crude product) at 95 ° C. The catalyst was adsorbed by stirring for 30 minutes and subjected to solid-liquid separation by pressure filtration at 80 ° C. to obtain a secondary intermediate A ′ (methanol-5PO). Thereafter, the secondary intermediate A ′ is put into a 5 L four-necked flask, and the temperature is raised from normal temperature to 260 ° C. while gradually reducing the pressure from normal pressure to 5 Torr (0.7 kPa). A low-boiling fraction of 0 to 2 and a high-boiling fraction having an addition mole number of PO of 8 or more were removed to obtain a tertiary intermediate A ′ (methanol-5PO, distilled product).
Thereafter, methyl oleate (C18 mixed fatty acid methyl ester derived from palm oil-derived carbon number fraction (C16 / C18: 0 / C18: 1 / C18: 2 = 3/10/70/17), trade name: pastel A′-1 (M182-5PO, R ¹ = C ₁₇ H ₃₃ ) was prepared in the same manner as in Production Example 2, except that M182 (manufactured by Lion Corporation) was used in an amount of 0.95 mol relative to 1 mol of the tertiary intermediate A ′. R ² = CH ₃ ) was obtained.

(Manufacture example 7) Manufacture of A'-2 With respect to 1 mol of secondary intermediate A '(methanol-5PO body) of manufacture example 6, methyl oleate (C18 mixed fatty acid derived from a C18 fraction derived from palm oil) Production Example 2 except that 0.95 mol of methyl ester (C16 / C18: 0 / C18: 1 / C18: 2 = 3/10/70/17), trade name: Pastel M182, manufactured by Lion Corporation) was used. Similarly, A′-2 (M182-5PO, R ¹ = C ₁₇ H ₃₃ , R ² = CH ₃ ) was obtained.

(Production Example 8) Production of B-4 360 g of isopropanol was used in place of the tertiary intermediate A of Production Example 1, and methyl laurate (fatty acid methyl ester derived from palm oil-derived 12 carbon fractions, trade name: Pastel M12 Except for using 1223 g (corresponding to 0.95 mol with respect to 1 mol of isopropanol), a transesterification reaction was carried out in the same manner as in Production Example 1 to obtain B-4 (C12-isopropyl, R ^{3 _{= C 11 H 23, R 4}} = CH (CH 3) 2) was obtained.

(Production Example 9) Production of C′-1 Using 313 g of neopentyl glycol instead of the tertiary intermediate A of Production Example 1, methyl caprate (derived from palm oil-derived 10 carbon fractions) instead of methyl laurate Fatty acid methyl ester, trade name: Pastel M10, manufactured by Lion Co., Ltd.) 1339 g (corresponding to 2.4 moles relative to 1 mole of neopentyl glycol) was used in the same manner as in Production Example 1 for transesterification. , C′-1 (neopentyl glycol-C10) was obtained.

(Examples 1-24, Comparative Examples 1-13)
According to the composition shown in Tables 2 to 4, each component was put into a 5 L four-necked flask and stirred at room temperature (25 ° C.) for 15 minutes. After stirring, the temperature was raised to 100 ° C., the pressure was reduced to 5 Torr (0.7 kPa), and dehydration was performed to obtain the lubricating base oil of each example. The obtained lubricating base oil was measured for kinematic viscosity, pour point, and mass reduction rate, and evaluated for viscosity index, additive solubility, and heat resistance. These results are shown in the table.
In addition, the compounding quantity of each component in a table | surface is a pure amount conversion amount.

As shown in Tables 2 to 4, Examples 1 to 24 to which the present invention was applied had a low 40 ° C. kinematic viscosity of 16.63 mm ² / s or less and a high viscosity index of 150 or more. It was. In addition, in Examples 1 to 24, the comprehensive evaluation of additive solubility was “◯”. Further, in Examples 1 to 24, the pour point was −22.5 ° C. or less and the fluidity at low temperature was high, and the evaluation of heat resistance was “◯” or “◎”.

On the other hand, in Comparative Examples 1, 5, and 6 using A′-1 instead of the component (A), the evaluation of the viscosity index was “x”, and the comprehensive evaluation of the additive solubility was “x”. In Comparative Example 2 using A′-2 instead of the component (A), the evaluation of the viscosity index was “◎”, but the additive solubility was “x”.
In Comparative Examples 3, 5, and 7 using the component (B ′) instead of the component (B), the comprehensive evaluation of additive solubility was “x” and the evaluation of heat resistance was “x”.
In Comparative Examples 4, 6, and 7 using the component (C ′) instead of the component (C), the comprehensive evaluation of additive solubility was “x”.
Comparative Example 9 in which the content of the component (A) is 5% by mass is Comparative Example 9 in which the evaluation of the viscosity index and the comprehensive evaluation of the additive solubility are “x”, and the content of the component (A) is 80% by mass. In No. 8, the evaluation of the viscosity index was “◎”, but the comprehensive evaluation of additive solubility was “x”.
In Comparative Example 10 in which the content of the component (B) is 3% by mass, the evaluation of the viscosity index is “◎”, but the comprehensive evaluation of the additive solubility is “x”, and the content of the component (B) In Comparative Example 11 having 70 mass%, the comprehensive evaluation of additive solubility and the evaluation of heat resistance were “x”.
Comparative Example 12 in which the content of the component (C) was 70% by mass and Comparative Example 13 in which the content of the (C) component was 3% by mass had an additive solubility of “x”.
From these results, it was found that by applying the present invention, the additive solubility was excellent, and both a low kinematic viscosity and a high viscosity index could be achieved.

Claims (1)

The fatty acid polyoxyalkylene alkyl ether (A) represented by the following general formula (I) and having a narrow rate of 55 to 80% represented by the following formula (1):
Fatty acid alkyl ester (B) represented by the following general formula (II) 5-60 mass%,
Fatty acid polyol ester (C) obtained by reacting a fatty acid or fatty acid alkyl ester represented by the following general formula (III) with a polyhydric alcohol represented by the following general formula (IV): Contains lubricating base oil.
R ¹ —CO—Q _n —OR ² (I)
(In the formula (I), R ¹ represents a linear monovalent hydrocarbon group having 7 to 19 carbon atoms, R ² represents a monovalent hydrocarbon group having 1 to 8 carbon atoms, and Q represents carbon. The oxyalkylene group of the number 2 to 4 is represented, and n is a number of 3 to 9 representing the average number of added moles of alkylene oxide.)
R ³ —COO—R ⁴ (II)
(In the formula (II), R ³ represents a linear monovalent hydrocarbon group having 7 to 19 carbon atoms, and R ⁴ represents a monovalent hydrocarbon group having 3 to 8 carbon atoms.)
R ⁵ —COO—R ⁶ (III)
(In the formula (III), R ⁵ represents a linear or branched monovalent saturated hydrocarbon group having 7 to 9 carbon atoms or a monovalent unsaturated hydrocarbon group having 17 to 19 carbon atoms; ⁶ represents hydrogen or a monovalent hydrocarbon group having 1 to 8 carbon atoms.)

(In the formula (IV), R ⁷ represents a monovalent hydrocarbon group or methylol group having 1 to 6 carbon atoms.)

(In formula (1), n _MAX represents the number of moles of alkylene oxide adduct of the alkylene oxide adduct most present on a mass basis in the whole alkylene oxide adduct, and i represents the number of moles of alkylene oxide added. Yi represents the proportion (% by mass) of the alkylene oxide adduct having an added mole number of alkylene oxide i present in the entire alkylene oxide adduct.