JP6231877B2 - Lubricating base oil containing dialkyl ether - Google Patents

Description

  The present invention relates to a lubricating base oil containing a dialkyl ether.

In recent years, there has been an increasing need for CO ₂ emission reduction from the viewpoint of protecting the global environment, and a great improvement in fuel efficiency has been demanded for lubricating oils. In order to save fuel consumption, reducing viscous resistance is one of the effective means, and various low-viscosity lubricating base oils have been developed. So far, for example, (1) ester (2) poly α-olefin (3) silicone oil and the like are known as low-viscosity lubricating base oils, but each has the following problems.
That is, (1) ester has a high polarity and has a problem of adverse effects on organic materials, and when used in engine oil, it swells rubber used in sealing materials and the like. (2) In the case of poly α-olefin, there is no adverse effect on the organic material, but it is difficult to achieve a balance between the viscosity index and the pour point (low temperature fluidity) as the viscosity decreases. (3) Some silicone oils have low viscosity, high viscosity index, and excellent low-temperature fluidity, but have problems such as poor lubricity and poor compatibility with existing additives.
As a solution to such a problem, a lubricating base oil containing a compound having an ether bond and having a kinematic viscosity at 40 ° C. or an aniline point limited to a specific range has been disclosed recently (see Patent Document 1). )

Lubricating base oils containing ether-bonded compounds have low viscosity, high viscosity index, excellent low-temperature fluidity, good compatibility with organic materials, and various lubricants including engine oils for internal combustion engines. Although it is effective as an oil, in order to meet the needs of further fuel saving, it is necessary to develop a base oil that has lower viscosity, has both viscosity-temperature characteristics and low-temperature fluidity at a high level, and has excellent lubricity There is.
That is, the kinematic viscosity at 100 ° C. of the lubricating base oil disclosed in Patent Document 1 is 3.2 to 2.4 mm ² / s, but the viscosity index decreases as the viscosity decreases. Further, when the viscosity is further lowered, it is not clarified how the structure can keep the viscosity index and low temperature fluidity of the base oil in a good balance. Patent Document 2 discloses a lubricating base oil relating to a monoether, but discloses only a combination of a part of the alkyl groups at both terminal alkyl groups.
Moreover, it is not efficient to produce a lubricating base oil containing pure dialkyl ether on an industrial scale. To what extent unreacted raw materials, by-products and the like are contained in the lubricating base oil containing the dialkyl ether of the present invention has not been studied.

International Publication WO2004 / 058928 JP 2005-344017 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lubricating base oil that is excellent in viscosity-temperature characteristics and low-temperature fluidity and exhibits low friction characteristics while having low viscosity. is there.

（式中、Ｒ¹及びＲ²は、それぞれ独立に、炭素数１〜２０のアルキル基を示し、ｎは１〜２０の整数を示す。）

（式中、ｐ及びｑは、それぞれ独立に１〜２０の整数を示す。）
２．前記一般式（１）におけるＲ²が、炭素数３〜１０の分岐状アルキル基である上記１に記載の潤滑油基油。
３．前記一般式（１）におけるＲ¹が、炭素数１〜３の直鎖状アルキル基である上記１又は２に記載の潤滑油基油。
４．前記一般式（１）におけるＲ¹が、メチル基である上記３に記載の潤滑油基油。
５．前記一般式（１）におけるｎが７〜２０の整数を示す上記１〜４のいずれかに記載の潤滑油基油。
６．前記ジアルキルエーテルＡの総炭素数が３０以下である上記１〜５のいずれかに記載の潤滑油基油。
７．ジアルキルエーテルＡのアニリン点が４０℃以上である上記１〜６のいずれかに記載の潤滑油基油。
８．ジアルキルエーテルＡの引火点が１４０℃以上である上記１〜７のいずれかに記載の潤滑油基油。
９．ジアルキルエーテルＡの流動点が０℃以下である上記１〜８のいずれかに記載の潤滑油基油。
１０．さらに、炭化水素化合物を含有する上記９に記載の潤滑油基油。
１１．前記炭化水素化合物がポリα―オレフィンである上記１０に記載の潤滑油基油。
１２．駆動系用である上記１〜１１のいずれかに記載の潤滑油基油。
１３．内燃機関用である上記１〜１１のいずれかに記載の潤滑油基油。 As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by dialkyl ethers in which the positions of branches are specified.
That is, the present invention provides the following.
1. Lubricating oil containing dialkyl ether A represented by the following general formula (1) and having a content of dialkyl ether B represented by the following general formula (2) of 0.1% by mass or more and 5.0% by mass or less Base oil.

(Wherein, R ¹ and R ² each independently represents an alkyl group having 1 to 20 carbon atoms, n is an integer of 1-20.)

(In formula, p and q show the integer of 1-20 each independently.)
2. ^2. The lubricating base oil according to 1 above, wherein R ² in the general formula (1) is a branched alkyl group having 3 to 10 carbon atoms.
3. 3. The lubricating base oil according to 1 or 2, wherein R ¹ in the general formula (1) is a linear alkyl group having 1 to 3 carbon atoms.
4). 4. The lubricating base oil according to 3 above, wherein R ¹ in the general formula (1) is a methyl group.
5. The lubricating base oil according to any one of 1 to 4 above, wherein n in the general formula (1) represents an integer of 7 to 20.
6). The lubricating base oil according to any one of 1 to 5 above, wherein the total number of carbon atoms of the dialkyl ether A is 30 or less.
7). The lubricating base oil according to any one of 1 to 6 above, wherein the aniline point of the dialkyl ether A is 40 ° C or higher.
8). The lubricating base oil according to any one of 1 to 7 above, wherein the flash point of the dialkyl ether A is 140 ° C or higher.
9. The lubricating base oil according to any one of 1 to 8 above, wherein the pour point of the dialkyl ether A is 0 ° C or lower.
10. Furthermore, the lubricating base oil of said 9 containing a hydrocarbon compound.
11. 11. The lubricating base oil according to 10 above, wherein the hydrocarbon compound is a poly α-olefin.
12 The lubricating base oil according to any one of 1 to 11 above, which is used for a drive system.
13. The lubricating base oil according to any one of 1 to 11 above, which is for an internal combustion engine.

  ADVANTAGE OF THE INVENTION According to this invention, although it is low viscosity, it can provide the lubricating base oil which is excellent in a viscosity-temperature characteristic and low-temperature fluidity | liquidity, and shows a low friction characteristic.

  The lubricating base oil of the present invention contains a dialkyl ether A represented by the general formula (1) described later, and a content of the dialkyl ether B represented by the general formula (2) described later is 0.1% by mass. It is characterized by being 5.0 mass% or less.

[Dialkyl ether A]
The dialkyl ether A is represented by the following general formula (1).

（式中、Ｒ¹及びＲ²は、それぞれ独立に、炭素数１〜２０のアルキル基を示し、ｎは１〜２０の整数を示す。）

(Wherein, R ¹ and R ² each independently represents an alkyl group having 1 to 20 carbon atoms, n is an integer of 1-20.)

In the general formula (1), examples of the alkyl group represented by R ¹ and R ² include linear or branched ones.
Examples of the linear alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, An n-decyl group etc. are mentioned.
Specific examples of the branched alkyl group include isopropyl group, 1-methylpropyl group, 2-methylpropyl group, t-butyl group, 1,1-dimethylpropyl group, 2,2-dimethylpropyl group, 1,2 -Dimethylpropyl group, 1-ethylpropyl group, 2-ethylpropyl group, 1,1-diethylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1,1-dimethylbutyl group, 2, 2-dimethylbutyl group, 3,3-dimethylbutyl group, 1,3,3-trimethylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-propylbutyl group, 1-methylpentyl group, 2-methylpentyl Group, 3-methylpentyl group, 4-methylpentyl group, 4,4-dimethylpentyl group, 1-ethylpentyl group, 2-ethylpentyl group, 3-e Rupentyl group, 4-ethylpentyl group, 1-propylpentyl group, 2-propylpentyl group, 1-butylpentyl group, 1-methylhexyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group 5-methylhexyl group, 5,5-dimethylhexyl group, 1-ethylhexyl group, 2-ethylhexyl group, 3-ethylhexyl group, 4-ethylhexyl group, 1-propylhexyl group, 2-propylhexyl group, 3-propyl Hexyl group, 1-butylhexyl group, 2-butylhexyl group, 1-methylheptyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 6-methylheptyl group 6,6-dimethylheptyl group, 1-ethylheptyl group, 2-ethylheptyl group, 3-ethylheptyl group Tyl group, 4-ethylheptyl group, 5-ethylheptyl group, 1-propylheptyl group, 2-propylheptyl group, 3-propylheptyl group, 1-methyloctyl group, 2-methyloctyl group, 3-methyloctyl group 4-methyloctyl group, 5-methyloctyl group, 6-methyloctyl group, 7-methyloctyl group, 7,7-dimethyloctyl group, 1-ethyloctyl group, 2-ethyloctyl group, 3-ethyloctyl group 4-ethyloctyl group, 5-ethyloctyl group, 6-ethyloctyl group, 1-methylnonyl group, 2-methylnonyl group, 3-methylnonyl group, 4-methylnonyl group, 5-methylnonyl group, 6-methylnonyl group, 7 -Methylnonyl group, 8-methylnonyl group, 3,5,5-trimethylhexyl group and the like.
R ¹ is preferably a linear alkyl group having 1 to 3 carbon atoms, and R ² is preferably a branched alkyl group having 3 to 10 carbon atoms.

N in the general formula (1) is preferably an integer of 7 to 20, and more preferably 8 to 16.
The dialkyl ether A represented by the general formula (1) preferably has a total carbon number of 30 or less, more preferably 10 to 25, in the whole molecule.
The dialkyl ether A preferably has an aniline point of 40 ° C. or higher, and more preferably 45 to 90 ° C. When the aniline point of the dialkyl ether A is 40 ° C. or higher, the sealing material made of plastic or rubber does not swell, and when it is 90 ° C. or lower, the sealing material does not shrink.
Furthermore, the dialkyl ether A preferably has a flash point of 140 ° C. or higher, and more preferably 150 ° C. or higher. When the flash point is 140 ° C. or higher, when the dialkyl ether A of the present invention is used as a base oil, the amount that evaporates and decreases is reduced, and the life is prolonged.
In addition, the dialkyl ether A preferably has a pour point of 0 ° C. or lower, more preferably −10 ° C. or lower.

The dialkyl ethers A is when the kinematic viscosity and QMM ² / s at a kinematic viscosity Pmm ² / s, 40 ℃ at 100 ℃, (a) P is 2.0 mm ² / s or more, and a viscosity index of 130 Or (b) P is preferably less than 2.0 mm ² / s and Q ≦ 4.478 × P-2.9234.

  As a manufacturing method of the said dialkyl ether A, the method of etherifying in an alkaline solution using raw material alkyl alcohol, an alkyl halide, and a phase transfer catalyst, washing | cleaning a reaction liquid, and distilling and purifying is mentioned.

  Examples of the raw material alkyl alcohol include 3,4-dimethylpentanol, 3,4-dimethylhexanol, 3,5,5-trimethylhexanol, 3,4,5-trimethylhexanol, 3,5-dimethylhexanol, 3 , 4,4-trimethylhexanol, 3,4-dimethylheptanol, 3,5-dimethylheptanol, 3,6-dimethylheptanol, 3,4,4-trimethylheptanol, 3,5,5-trimethylhepta Nord, 3,6,6-trimethylheptanol, 3,4,6,6-tetramethylheptanol, 3,4-dimethyloctanol, 3,5-dimethyloctanol, 3,6-dimethyloctanol, 3,7- Dimethyloctanol, 3,7,7-trimethyloctanol, 3,4-dimethylnonanol, , 5-dimethylnonanol, 3,6-dimethylnonanol, 3,7-dimethylnonanol, 3,8-dimethylnonanol, 3,8,8-trimethylnonanol, 3,4-dimethyldecanol, 3, , 5-dimethyldecanol, 3,6-dimethyldecanol, 3,7-dimethyldecanol, 3,8-dimethyldecanol, 3,9-dimethyldecanol, 3,9,9-trimethyldecanol, 3, , 4-dimethylundecanol, 3,5-dimethylundecanol, 3,6-dimethylundecanol, 3,7-dimethylundecanol, 3,8-dimethylundecanol, 3,9-dimethylun Decanol, 3,10-dimethylundecanol, 3,10,10-trimethylundecanol, 3,4-dimethyldodecanol, 3,5-dimethyldodecane Diol, 3,6-dimethyldodecanol, 3,7-dimethyldodecanol, 3,8-dimethyldodecanol, 3,9-dimethyldodecanol, 3,10-dimethyldodecanol, 3,11-dimethyldodecanol, Examples include 3,6,8,8-tetramethylnonanol.

  Examples of the alkyl halide include chloroethane, bromoethane, iodoethane, 1-chloropropane, 1-bromopropane, 1-iodopropane, 1-chlorobutane, 1-bromobutane, 1-iodobutane, 1-chloropentane, 1-bromopentane, 1-iodopentane, 1-chlorohexane, 1-bromohexane, 1-iodohexane, 1-chloroheptane, 1-bromoheptane, 1-iodoheptane, 1-chlorooctane, 1-bromooctane, 1-iodooctane, 1-chlorononane, 1-bromononane, 1-iodononane, 1-chlorodecane, 1-bromodecane, 1-iododecane, 1-chloroundecane, 1-bromoundecane, 1-iodoundecane, 1-chlorododecane, 1-bromododecane, 1 -Iodododecane 1-chlorotridecane, 1-bromotridecane, 1-iodotridecane, 1-chlorotetradecane, 1-bromotetradecane, 1-iodotetradecane, 1-chloropentadecane, 1-bromopentadecane, 1-iodopentadecane, 1- Chlorohexadecane, 1-bromohexadecane, 1-iodohexadecane, 1-chloroheptadecane, 1-bromoheptadecane, 1-iodoheptadecane, 1-chlorooctadecane, 1-bromooctadecane, 1-iodooctadecane, 1-chlorononadecane, 1-bromononadecane, 1-iodononadecane, 1-chloroeicosan, 1-bromoeicosan, 1-iodoeicosan, 1-chlorohenicosan, 1-bromohenicosan, 1-iodohenicosan .

  Examples of the phase transfer catalyst include salts having a long-chain alkylammonium cation, such as tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, trioctylmethylammonium chloride, trioctylmethylammonium bromide, tritium. Examples include octylmethylammonium iodide, benzyldimethyloctadecylammonium chloride, benzyldimethyloctadecylammonium bromide, and benzyldimethyloctadecylammonium iodide.

As the reaction conditions for the above reaction, preferably, in addition to the raw material and the phase transfer catalyst, a high-concentration alkaline aqueous solution such as a 50% aqueous sodium hydroxide solution is added, and the temperature is 50 ° C. to 90 ° C. with strong stirring. React for 4-10 hours.
At this time, it is preferable to carry out a post-treatment after the reaction solution is separated from oil and water and repeatedly washed with water or saturated saline until the oil layer becomes neutral.
As a specific example of the distillation method, a thermometer, capillary, cooling tube, receiver, dry ice trap, vacuum pump, manometer, etc. are attached to a Claisen flask containing the reaction mixture. The target is distilled from the mixture while bubbling the gas. At this time, when the distillation temperature reaches the boiling point of the target product, the receiver is replaced to collect the target product.

[Dialkyl ether B]
The dialkyl ether B is represented by the following general formula (2).

（式中、ｐ及びｑは、それぞれ独立に１〜２０の整数を示す。）

(In formula, p and q show the integer of 1-20 each independently.)

  In the said General formula (2), it is preferable that p and q are respectively independently the integers of 7-20, and it is more preferable that it is an integer of 8-16.

[Lubricant base oil]
The lubricating base oil of the present invention contains one or more of the above dialkyl ethers A.
The content of the dialkyl ether B in the total amount of the lubricating base oil of the present invention is 5.0% by mass or less, preferably 3.0% by mass or less, more preferably 2.0% by mass or less, Preferably they are 0.1 mass% or more and 1.0 mass% or less. In the total amount of the lubricating base oil of the present invention, if the content of the dialkyl ether B is less than 0.1% by mass, the friction coefficient increases and the energy saving performance is inferior, while the content of the dialkyl ether B is 5. If it exceeds 0% by mass, the pour point rises and the low temperature fluidity deteriorates. In the case of a lubricating base oil composed of dialkyl ethers A and B, the content of dialkyl ether A in the total amount of the lubricating base oil of the present invention is preferably 93.0% by mass to 99.9% by mass.
In addition to the dialkyl ether A and dialkyl ether B, the lubricating base oil of the present invention may contain one or more other base oils such as mineral oil and hydrocarbon compounds. In that case, the content of the dialkyl ether A in the total amount of the lubricating base oil of the present invention is 10% by mass to 90% by mass, preferably 20% by mass to 80% by mass. Depending on the combination with other base oil, it may be 90% by mass or more.
Moreover, even if it contains 1 or more types of other base oil, content of the dialkyl ether B in the lubricating base oil whole quantity of this invention is 5.0 mass% or less, Preferably it is 3.0 mass% or less. Yes, more preferably 2.0% by mass or less, still more preferably 0.1% by mass or more and 1.0% by mass or less.
Examples of the hydrocarbon compound include poly α-olefin, ethylene-propylene copolymer, ester (monoester, diester, polyester, etc.), polyether (polyalkylene glycol, etc.), alkylbenzene, and the like.

The lubricating base oil of the present invention preferably has a kinematic viscosity at 100 ° C. of 5.0 mm ² / s or less, more preferably 4.5 mm ² / s or less, and 3.0 mm ² / s or less. More preferably, it is particularly preferably 2.7 mm ² / s or less, and most preferably 2.5 mm ² / s or less. When the kinematic viscosity and the viscosity index at 100 ° C. are within the above ranges, low viscosity, low evaporation, energy saving and fuel saving can be realized.

  Applications of the lubricating base oil of the present invention include, for example, for internal combustion engines, drive systems, hydraulic fluids, automatic transmission oils, continuously variable transmissions, manual transmission oils, shock absorber oils, gear oils, fluid bearing oils, Examples thereof include rolling bearing oil, oil-impregnated bearing oil, sliding surface oil, and refrigeration oil, and are particularly suitable for continuously variable transmissions.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

Comparative Example 1 [Synthesis of 1- (3,5,5-trimethylhexoxy) decane]

In a 2 liter glass flask, 144 g of 3,5,5-trimethyl-1-hexanol, 221 g of 1-bromodecane, 32 g of tetrabutylammonium bromide, 454 g of an aqueous sodium hydroxide solution (dissolved 236 g of sodium hydroxide in 218 g of water) The mixture was stirred at 70 ° C. for 5 hours to be reacted.
After completion of the reaction, the reaction mixture is transferred to a separatory funnel, the aqueous layer is filtered off, and the remaining organic layer is washed 5 times with 500 ml of water to give 1- (3,5,5-trimethylhexoxy) decane. A crude product containing was obtained.
Furthermore, this crude product was put into a glass distillation apparatus equipped with a Vigreux column, and the temperature of the bottom of the distillation apparatus was adjusted to 138 to 142 ° C. and the pressure in the apparatus was adjusted to 2.0 to 3.0 Torr. 180 g of 1- (3,5,5-trimethylhexoxy) decane (distillation temperature: 110 to 124 ° C.) containing no ether was obtained.

  With respect to 1- (3,5,5-trimethylhexoxy) decane obtained as described above, its kinematic viscosity, viscosity index, pour point, aniline point, and flash point were measured by the following measurement method. . The results are shown in Table 1.

(1) Kinematic viscosity Measured according to the method described in JIS K2283.
(2) Viscosity index Measured according to the method described in JIS K2283.
(3) Pour point Measured according to the method described in JIS K2269.
(4) Aniline point Measured according to the method described in JIS K2256.
(5) Flash point Measured according to the method described in JIS K2265.
(6) Friction characteristics Using a ball-on-disk type reciprocating friction tester (Bowden-Leven type), the friction coefficient and the wear width were measured at a load of 10 N, a temperature of 40 ° C., a sliding speed of 30 mm ² / s, and a stroke of 15 mm. The ball is made of material SUJ2 and the diameter is 10 mm, and the disk is made of material SUJ2. It can be said that the smaller the coefficient of friction, the better the lubricity.

Examples 1 to 5 and Comparative Example 2
The 1- (3,5,5-trimethylhexoxy) decane obtained in Comparative Example 1 is blended with decyl ether in the proportions shown in Table 1, and the resulting mixture has a kinematic viscosity, viscosity index, and pour point. The aniline point and flash point were measured in the same manner as in Example 1. The measurement results are shown in Table 1.

  As is clear from the comparison between Examples 1 to 5 and Comparative Examples 1 and 2 shown in Table 1, the lubricating base oil of the present invention is excellent in viscosity-temperature characteristics and low-temperature fluidity while being low in viscosity. In addition, it has a low friction coefficient and excellent properties as a lubricating base oil.

  The lubricating base oil of the present invention is useful for internal combustion engine applications, drive system applications and the like because it has a low viscosity, is excellent in viscosity-temperature characteristics and low-temperature fluidity, and exhibits low friction characteristics.

Claims (13)

Lubricating oil containing dialkyl ether A represented by the following general formula (1) and having a content of dialkyl ether B represented by the following general formula (2) of 0.1% by mass or more and 5.0% by mass or less Base oil.

(Wherein, R ¹ and R ² each independently represents an alkyl group having 1 to 20 carbon atoms, n is an integer of 1-20.)

(In formula, p and q show the integer of 1-20 each independently.) The lubricating base oil according to claim 1, wherein R ² in the general formula (1) is a branched alkyl group having 3 to 10 carbon atoms. The lubricating base oil according to claim 1 or 2, wherein R ¹ in the general formula (1) is a linear alkyl group having 1 to 3 carbon atoms. The lubricating base oil according to claim 3, wherein R ¹ in the general formula (1) is a methyl group.   The lubricating base oil according to any one of claims 1 to 4, wherein n in the general formula (1) represents an integer of 7 to 20.   The lubricating base oil according to claim 1, wherein the dialkyl ether A has a total carbon number of 30 or less.   The lubricating base oil according to claim 1, wherein the dialkyl ether A has an aniline point of 40 ° C. or higher.   The lubricating base oil according to any one of claims 1 to 7, wherein the flash point of the dialkyl ether A is 140 ° C or higher.   The lubricating base oil according to any one of claims 1 to 8, wherein the pour point of the dialkyl ether A is 0 ° C or lower.   The lubricating base oil according to claim 9, further comprising a hydrocarbon compound.   The lubricating base oil according to claim 10, wherein the hydrocarbon compound is a poly α-olefin.   The lubricating base oil according to any one of claims 1 to 11, which is used for a drive system.   The lubricating base oil according to any one of claims 1 to 11, which is used for an internal combustion engine.