JP2020164497A - New compound, viscosity index improver, and lubricant composition - Google Patents

Abstract

To provide a viscosity index improver excellent in shear stability, and a lubricant composition containing the viscosity index improver.SOLUTION: The invention provides a compound represented by the general formula (1) in the figure, and a polymer comprising a constitutional unit (a) derived from the general formula (1). (In the general formula (1), R1 represents a hydrogen atom or methyl group; R2, R3, R4 and R5 each independently represent a C2-18 alkyl group; and m and n each independently represent an integer from 1 to 10.)SELECTED DRAWING: None

Description

The present invention relates to novel compounds, viscosity index improvers and lubricating oil compositions.

In recent years, drive system oils such as automatic transmission fluid (ATF), stepless transmission oil (CVTF), and shock absorber oil (SAF), and lubricating oil compositions used as internal combustion engine oil, hydraulic hydraulic oil, and the like have been used. Various characteristics are required depending on the application.
For example, regarding fuel efficiency of automobiles, we have improved the weight of automobiles, improved engines, etc., as well as reduced the viscosity of lubricating oils to prevent friction loss in drive system equipment and engines, and for various types of lubricating oils. Improvement of lubricating oil such as addition of additives is also important. However, since the lubricating oil is used in a wide temperature range, simply reducing the viscosity causes the oil film at the lubricating portion to become thinner under high temperature conditions, resulting in increased wear and seizure due to contact between the members. It causes a problem such as. Therefore, it is desirable that the viscosity of the lubricating oil does not change as much as possible over a wide temperature range. Therefore, for example, a method of adding a viscosity index improver to improve the temperature dependence of viscosity is generally used for a lubricating oil used in a wider temperature range from a high temperature range to a low temperature range.
For example, Patent Document 1 discloses a viscosity index improver containing a copolymer containing a monomer having a specific structure as an essential constituent monomer.
Further, Patent Document 2 describes a viscosity index improver containing a copolymer containing a monomer having a specific branched structure as an essential constituent monomer, wherein the copolymer has a specific weight average molecular weight. Viscosity index improvers that satisfy the molecular weight distribution and solubility parameters are disclosed.
Further, Patent Document 3 describes a hydrocarbon-based synthetic base oil viscosity index improver containing a copolymer that satisfies a specific solubility parameter and contains a monomer having a specific structure as an essential constituent monomer. It is disclosed.
Further, Patent Document 4 describes a copolymer containing a monomer having a specific structure as an essential constituent monomer and an ester base oil having a kinematic viscosity of 1.0 to 2.5 mm ² / s at 100 ° C. A viscosity index improver composition comprising the above is disclosed.

Japanese Unexamined Patent Publication No. 2014-152316 Japanese Unexamined Patent Publication No. 2014-136772 JP-A-2015-38194 JP-A-2017-57378

As described above, various viscosity index improvers have been used and studied to improve the viscosity index of lubricating oil compositions.
By the way, the viscosity index of the lubricating oil composition is proportional to the molecular weight of the polymer compound used as the viscosity index improver, but on the other hand, the higher the molecular weight, the more susceptible to mechanical shearing, and the decomposition of the polymer compound. There is a problem that the viscosity is lowered. Then, the conventional viscosity index improver has a problem that the shear stability is not yet sufficient.
Therefore, the viscosity index improver is required to have better shear stability in addition to the effect of improving the viscosity index.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a viscosity index improver having excellent shear stability and a lubricating oil composition containing the viscosity index improver. is there.

As a result of diligent studies, the present inventors have found that a polymer containing a structural unit derived from a compound having a specific structure can solve the above-mentioned problems. Each embodiment of the present invention has been completed based on such findings. That is, according to each embodiment of the present invention, the following [1] to [16] are provided.
[1] The compound represented by the following general formula (1).

(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 2 to 18 carbon atoms. n represents an integer of 1 to 10 independently of each other.)

[2] The compound according to the above [1], which is a monomer constituting a polymer used as a viscosity index improver for a lubricating oil composition.
[3] A polymer containing a structural unit (a) derived from a compound represented by the following general formula (1).

(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 2 to 18 carbon atoms. n represents an integer of 1 to 10 independently of each other.)

[4] Further, a structural unit (b) derived from a compound represented by the following general formula (2), a structural unit (c) derived from a (meth) acrylate having a linear alkyl group having 1 to 4 carbon atoms, and a carbon number. The polymer according to the above [3], which is a copolymer containing at least one structural unit selected from the group consisting of the structural unit (d) derived from (meth) acrylate having a linear alkyl group of 8 to 36. ..

(In the general formula (2), R ¹ represents a hydrogen atom or a methyl group, R ⁶ represents a linear or branched alkylene group having 2 to 4 carbon atoms, and R ⁷ and R ⁸ are independent carbon atoms. .p indicating the number 2-18 alkyl groups may, when the .p is 2 or more represents an integer of 0 to 20, ^{R 6} existing in plural numbers may be the same or different.)
[5] In the above [3] or [4], the content of the structural unit (a) is 5 to 70% by mass based on 100% by mass of the total amount of the structural units excluding the terminal structural units in the molecular structure. The polymer described.
[6] The polymer according to any one of [3] to [5] above, wherein the weight average molecular weight is 5,000 to 2,000,000.
[7] The polymer according to any one of [3] to [6] above, which is used as a viscosity index improver for a lubricating oil composition.
[8] A lubricating oil composition containing the polymer according to any one of [3] to [7] above and a base oil.

[9] A viscosity index improver, which is the polymer according to any one of [3] to [7] above.
[10] A method for producing a compound represented by the following general formula (1), which comprises the following steps (1) and (2).
Step 1: A step of reacting epichlorohydrin with a branched alcohol having a branched position at a position other than the α position to obtain a glycerin diether, or an alkyl glycidyl ether having a branched alkyl group other than the α position. A step of reacting with a branched alcohol having a branched position at the position to obtain a glycerin diether.
Step 2: A step of obtaining a compound represented by the following general formula (1) by an esterification reaction between the glycerin diether obtained in Step 1 and (meth) acrylic acid.

(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 2 to 18 carbon atoms. n represents an integer of 1 to 10 independently of each other.)

[12] The method for producing a polymer according to the above [3].
[13] A method for producing a lubricating oil composition, which comprises blending the polymer according to the above [3] with the base oil (A).
[14] A lubrication method comprising using the lubricating oil composition according to the above [8].
[15] A drive system device using the lubricating oil composition according to the above [8].
[16] An internal combustion engine using the lubricating oil composition according to the above [8].

According to the present invention, it is possible to provide a viscosity index improver having excellent shear stability and a lubricating oil composition containing the viscosity index improver.

Synthesized in Synthesis Example 1 2- (2-ethylhexoxy) -1- (2-ethylhexoxide) ethyl ^{methacrylate, 1} H-NMR spectrum chart when was confirmed by the 1 H-NMR measurement. Synthesized in Synthesis Example 2 2- (2-hexyl Deco carboxymethyl) -1- (2-hexyl Deco carboxymethyl) ethyl ^{methacrylate, 1} H-NMR spectrum chart when was confirmed by the 1 H-NMR measurement. The 2- (2-decyltetradecoxy) -1- (2-decyltetradecoxymethyl) ethyl methacrylate synthesized in Synthesis Example 3 is shown in the ¹ H-NMR spectrum chart when confirmed by ^{1 1} H-NMR measurement. is there.

Hereinafter, when the term "viscosity index improving effect" is simply described in the present specification, it means the effect of improving the viscosity index of the lubricating oil composition possessed by the polymer according to one aspect of the present invention.
Moreover, when it is simply described as "shear stability" in this specification, it means the shear stability of a polymer which is one aspect of the present invention.

Further, in the present specification, the lower limit value and the upper limit value described stepwise with respect to a preferable numerical range (for example, a range such as content) can be independently combined. For example, a description of a lower limit value of "preferably 10 or more, more preferably 30 or more, still more preferably 40 or more" and an upper limit value of "preferably 90 or less, more preferably 80 or less, still more preferably 70 or less". From the description of the above, as a suitable range, for example, a range in which a lower limit value and an upper limit value independently selected such as "10 or more and 70 or less", "30 or more and 70 or less", and "40 or more and 80 or less" are combined is selected. You can also do it. Further, from the same description, for example, it is possible to simply select a range in which one of the lower limit value and the upper limit value such as "40 or more" or "70 or less" is defined. Further, for example, "preferably 10 or more and 90 or less, more preferably 30 or more and 80 or less, still more preferably 40 or more and 70 or less", "preferably 10 to 90, more preferably 30 to 80, still more preferably 40 to 40 to". The same applies to the preferable range that can be selected from the description such as "70". In the description of the numerical range in the present specification, for example, the description "10 to 90" is synonymous with "10 or more and 90 or less".
Further, in the present specification, the “hydrocarbon group” means a group composed of only a carbon atom and a hydrogen atom. "Hydrocarbon groups" include "aliphatic groups" composed of straight or branched chains, "aliphatic groups" having one or more saturated or unsaturated carbon rings having no aromaticity, benzene rings, etc. An "aromatic group" having one or more aromatic rings exhibiting aromaticity is included.
Further, in the present specification, the “ring-forming carbon number” represents the number of carbon atoms among the atoms constituting the ring itself of the compound having a structure in which atoms are cyclically bonded. When the ring is substituted with a substituent, the carbon contained in the substituent is not included in the ring-forming carbon number.
Further, in the present invention, for example, "(meth) acrylate" means both "acrylate" and "methacrylic acid", and "(meth) acrylic acid" means both "acrylic acid" and "methacrylic acid". And other similar terms as well.
Hereinafter, each preferred embodiment of the present invention will be described in detail.

[Compound represented by the general formula (1)]
The compound according to one aspect of the present invention is represented by the following general formula (1).

(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 2 to 18 carbon atoms. n represents an integer of 1 to 10 independently of each other.)

The preferred embodiment represented by each reference numeral in the general formula (1) is shown below.
R ¹ preferably represents a methyl group from the viewpoint of improving the viscosity index.
R ^{2, R 3,} R ⁴ and R ⁵ are each independently, improved shear stability, the effect of the viscosity index improver, from the viewpoint of solubility in the base oil of the resulting polymer, preferably 2 to carbon atoms It shows 16 alkyl groups, more preferably 2 to 14 alkyl groups, even more preferably 2 to 12 alkyl groups.
R ^{2, R} 3, ^{R 4} and ^{R 5} may be the same or different from each other.
The alkyl group having 2 to 18 carbon atoms represented by R ² , R ³ , R ⁴ and R ⁵ may be either a linear or branched alkyl group, and is preferably a linear alkyl group.
m and n are independently, preferably an integer of 1 to 6, more preferably an integer of 1 to 3, still more preferably an integer of 1 or 2, and even more preferably 1.
Further, as an example of a preferable embodiment of the compound represented by the general formula (1), for example, it is preferable that R ² and R ³ are different from each other and R ⁴ and R ⁵ are different from each other. It is more preferable that R ² and R ³ are different from each other, R ⁴ and R ⁵ are different from each other, R ² and R ⁴ are the same, and R ³ and R ⁵ are the same. When the compound represented by the general formula (1) satisfies the above embodiment, for example, R ² and R ⁴ are independently obtained from the viewpoints of shear stability, effect of improving viscosity index, and solubility in base oil. It preferably represents an alkyl group having 2 to 14 carbon atoms, more preferably 2 to 14 alkyl groups, and even more preferably 2 to 12 alkyl groups. Then, R ³ and R ⁵ are independently each of an alkyl group having 2 to 16 carbon atoms, more preferably an alkyl group having 4 to 14 carbon atoms, and further preferably an alkyl group having 6 to 14 carbon atoms from the same viewpoint as described above. Is shown.

Examples of specific examples of the compound represented by the general formula (1) include 2- (2-ethylhexoxy) -1- (2-ethylhexoxymethyl) ethyl methacrylate and 2- (2-butyloctoxy). Xi) -1- (2-butyloctoxymethyl) ethyl methacrylate, 2- (2-hexyldecoxy) -1- (2-hexyldecoxymethyl) ethyl methacrylate, 2- (2-octyldodecoxy)- 1- (2-octyldodecoxymethyl) ethyl methacrylate, 2- (2-decyltetradecoxy) -1- (2-decyltetradecoxymethyl) ethyl methacrylate, 2- (2-dodecylhexadecoxy)- Examples thereof include 1- (2-dodecyl hexadecoxymethyl) ethyl methacrylate and 2- (2-tetradecyl octadecoxy) -1- (2-tetradecyl octadecoxymethyl) ethyl methacrylate.
Among the specific examples, the compound represented by the general formula (1) is preferably 2- (2-ethylhexoxy) -1- (2-ethylhexoxymethyl) ethyl methacrylate, 2- (2- (2-). Hexyldecoxy) -1- (2-hexyldecoxymethyl) ethyl methacrylate, 2- (2-decyltetradecoxy) -1- (2-decyltetradecoxymethyl) ethyl methacrylate, and 2- (2-tetra. One or more selected from the group consisting of decyloctadecoxy) -1- (2-tetradecyloctadecoxymethyl) ethyl methacrylate, more preferably 2- (2-ethylhexoxy) -1- (2-ethylhexoxymethyl) ) Ethyl methacrylate, 2- (2-hexyldecoxy) -1- (2-hexyldecoxymethyl) ethyl methacrylate, and 2- (2-decyltetradecoxy) -1- (2-decyltetradecoxymethyl) One or more selected from the group consisting of ethyl methacrylate.

The compound represented by the general formula (1) is preferably used as a monomer constituting a polymer which is one aspect of the present invention described later. When the polymer according to one aspect of the present invention described later is used as a viscosity index improver, the compound represented by the general formula (1) is used as a viscosity index improver for the lubricating oil composition. It can be more preferably used as a monomer constituting a polymer.
The polymer according to one aspect of the present invention containing the structural unit derived from the compound represented by the general formula (1) can be suitably used as a viscosity index improver having excellent shear stability, and the viscosity thereof. The lubricating oil composition according to one aspect of the present invention using the index improver has a high viscosity index and excellent shear stability. Therefore, the compound represented by the general formula (1) is an important compound for achieving the effects of the present application.

[Method for producing compound represented by general formula (1)]
The method for producing the compound represented by the general formula (1) has the following steps 1 and 2.
Step 1: A step of reacting epichlorohydrin with a branched alcohol having a branched position at a position other than the α position to obtain a glycerin diether, or an alkyl glycidyl ether having a branched alkyl group other than the α position. A step of reacting with a branched alcohol having a branched position at the position to obtain a glycerin diether.
Step 2: A step of obtaining a compound represented by the following general formula (1) by an esterification reaction between the glycerin diether obtained in Step 1 and (meth) acrylic acid.

(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 2 to 18 carbon atoms. n represents an integer of 1 to 10 independently of each other.)

<Process (1)>
The step 1 is a step of reacting epichlorohydrin with a branched alcohol having a branched position other than the α position to obtain a glycerin diether, or an alkyl glycidyl ether having a branched alkyl group and the α position. This is a step of reacting with a branched alcohol having a branched position other than the above to obtain a glycerin diether.
Examples of the branched alcohol having a branched position other than the α-position include alcohols represented by the following general formula (1-1).

(In the general formula (1-1), R ¹⁰ and R ¹¹ each independently represent an alkyl group having 2 to 18 carbon atoms. S represents an integer of 1 to 10.)

R ¹⁰ and R ¹¹ in the general formula (1-1) are the same as the alkyl groups having 2 to 18 carbon atoms represented by R ² , R ³ , R ⁴ and R ⁵ in the general formula (1) described above. , The preferred embodiment is the same. That is, R ¹⁰ and R ¹¹ in the general formula (1-1) correspond to R ² and R ³ in the above-mentioned general formula (1) and / or R ⁴ and R ⁵ .
s is preferably an integer of 1 to 6, more preferably an integer of 1 to 3, still more preferably an integer of 1 or 2, and even more preferably 1. The s in the general formula (1-1) is the portion corresponding to m and / or n in the above-mentioned general formula (1).

As the branched alcohol having a branched position at a position other than the α position, a branched alcohol having a branched position at the β position is preferable. To give a specific example of the alcohol, for example, 2-ethyl-1-hexanol, 2-butyl-1-octanol, 2-hexyl-1-decanol, 2-octyl-1-dodecanol, 2-decyl-1 -Tetradecanol, 2-dodecyl-1-hexadecanol, 2-tetradecyl-1-octadecanol and the like can be mentioned.

Examples of the alkyl glycidyl ether having a branched alkyl group include alkyl glycidyl ethers represented by the following general formula (1-2).

(In the general formula (1-2), R ¹² and R ¹³ each independently represent an alkyl group having 2 to 18 carbon atoms. T represents an integer of 1 to 10.)

R ¹² and R ¹³ in the general formula (1-2) are the same as the alkyl groups having 2 to 18 carbon atoms represented by R ¹⁰ and R ¹¹ in the general formula (1-1) described above, and are preferred embodiments thereof. Is the same. That is, R ¹² and R ¹³ in the general formula (1-2) are parts corresponding to R ² and R ³ in the above-mentioned general formula (1), or R ⁴ and R ⁵ .
t is preferably an integer of 1 to 6, more preferably an integer of 1 to 3, still more preferably an integer of 1 or 2, and even more preferably 1. T in the general formula (1-2) is a portion corresponding to m or n in the above-mentioned general formula (1).

To give a specific example of the alkyl glycidyl ether represented by the general formula (1-2), for example, 2-ethylhesyl glycidyl ether, 2-butyloctyl glycidyl ether, 2-hexyldecyl glycidyl ether, 2- Examples thereof include octyldodecylglycidyl ether, 2-decyltetradecylglycidyl ether, 2-dodecylhexadecylglycidyl ether, 2-tetradecyloctadecylglycidyl ether and the like.

In the reaction of the epichlorohydrin or the alkylglycidyl ether having the branched alkyl group with the branched alcohol having a branched position other than the α position, for example, epichlorohydrin is used as a base and a phase transfer catalyst is present. Below, a method of reacting with a branched alcohol having a branched position other than the α-position to obtain a glycerin diether can be mentioned.
Examples of the base used in the step (1) include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, and sodium hydroxide is preferable from the viewpoint of reactivity in carrying out the reaction. And one or more selected from potassium hydroxide, more preferably sodium hydroxide.
Examples of the phase transfer catalyst include tetramethylammonium chloride, tetramethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetraoctylammonium chloride, and tetraoctylammonium bromide. Among these, one or more selected from tetrabutylammonium chloride and tetrabutylammonium bromide are preferable, and more preferably tetrabutylammonium bromide, from the viewpoint of reactivity when carrying out the reaction.

The temperature at which epichlorohydrin or an alkylglycidyl ether having a branched alkyl group is reacted with a branched alcohol having a branched position other than the α position in the presence of a base and a phase transfer catalyst is preferably 40 to 110 ° C. , More preferably 45 to 80 ° C, still more preferably 50 to 80 ° C.

The glycerin diether obtained in step 1 is a compound represented by the following general formula (1-3).

(In the general formula ^{(1-3), R 2, R} 3, R 4 and ^{R 5} are each independently, .m and n represent an alkyl group having 2 to 18 carbon atoms are each independently 1 to 10 Indicates an integer of.)

Formula (1-3) ^R 2 ^in, R 3, ^{R 4} and ^{R 5} each independently have the same meaning as ^{R 2,} R 3, ^{R 4} and ^{R 5} in the general formula (1) described above , The preferred embodiment thereof is also the same.
M and n in the general formula (1-3) are independently synonymous with m and n in the general formula (1) described above, and the preferred embodiments thereof are also the same.

Examples of specific examples of the compound represented by the general formula (1-3) include 1,3-bis (2-ethylhexoxy) propan-2-ol and 1,3-bis (2-butyloct). Xi) Propan-2-ol, 1,3-bis (2-hexyldecoxy) Propan-2-ol, 1,3-bis (2-octyldecoxy) Propan-2-ol, 1,3-bis ( 2-decyltetradecoxy) Propan-2-ol, 1,3-bis (2-dodecylhexadecoxy) propan-2-ol, and 1,3-bis (2-tetradecyloctadecoxy) propane-2 -Examples include oars.
The compounds represented by the general formula (1-3) are preferably 1,3-bis (2-ethylhexoxy) propan-2-ol and 1,3-bis (2-) in the specific examples. From hexyl decoxy) propane-2-ol, 1,3-bis (2-decyltetradecoxy) propane-2-ol, and 1,3-bis (2-tetradecyloctadecoxy) propane-2-ol One or more selected from the group, more preferably 1,3-bis (2-ethylhexoxy) propan-2-ol, 1,3-bis (2-hexyldecoxy) propan-2-ol, and 1,3. One or more selected from the group consisting of −bis (2-decyltetradecoxy) propan-2-ol.

In the reaction between the epichlorohydrin and a branched alcohol having a branched position at a position other than the α position, the amount of the epichlorohydrin blended per 1.0 mol of the branched alcohol having a branched position at a position other than the α position. Is preferably 0.5 to 1.0 mol. Here, the upper limit of the epichlorohydrin compounding amount includes a range exceeding 0.5 mol because it is necessary to consider the amount of epichlorohydrin volatilized during synthesis.
In the reaction between the alkyl glycidyl ether having a branched alkyl group and the branched alcohol having a branched position at a position other than the α position, the branched alkyl per 1.0 mol of the branched alcohol having a branched position at a position other than the α position. The blending amount of the alkylglycidyl ether having a group is preferably 0.9 to 1.1 mol, more preferably 1.0 mol.

<Process (2)>
The step 2 is a step of obtaining a compound represented by the following general formula (1) by an esterification reaction of the glycerin diether obtained in the step 1 with (meth) acrylic acid.

(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 2 to 18 carbon atoms. n represents an integer of 1 to 10 independently of each other.)

The compound represented by the general formula (1) is the same as that described above, and the preferred embodiment thereof is also the same.

In the reaction in step (2), the blending amount of the (meth) acryloyl chloride per 1.0 mol of the glycerin diether is preferably 1.0 to 2.0 mol.

The step (2) is preferably carried out in the presence of a base in order to neutralize hydrochloric acid, which is a by-product produced in the reaction. As the base used in the step (2), an organic base such as trimethylamine, triethylamine, N, N-dimethyl-4-aminopydin is preferable.
The amount of the base used is preferably the same molar amount as that of the (meth) acryloyl chloride.

After obtaining the compound represented by the general formula (1) by the reaction of the step (2), for example, a washing operation using ion-exchanged water or the like for the reaction solution after the reaction of the step (2). The compound represented by the general formula (1) can be purified and separated by performing a dehydration operation and a filtration operation with magnesium sulfate or the like, distilling off a light component, and then purifying by a column or distillation.

[Polymer]
The polymer according to one aspect of the present invention contains a structural unit (a) derived from a compound represented by the following general formula (1).

(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 2 to 18 carbon atoms. n represents an integer of 1 to 10 independently of each other.)

In the case of a polymer that does not contain the structural unit (a), the shear stability is lowered.
The compound represented by the general formula (1) is the same as that described in the section of the compound which is one aspect of the present invention described above, and the preferred embodiment thereof is also the same, and thus the description thereof will be omitted. ..
In addition, the compound represented by the general formula (1), which is the raw material of the structural unit (a), may be used alone or in combination of two or more of the above-mentioned compounds.

The content of the structural unit (a) in the polymer is based on 100% by mass of the total amount of the structural units excluding the terminal structural units in the molecular structure, and is preferably 5% by mass or more from the viewpoint of improving shear stability. , More preferably 7% by mass or more, further preferably 10% by mass or more, and from the viewpoint of improving the solubility in the base oil, preferably 70% by mass or less, more preferably 60% by mass or less, still more preferable. Is 45% by mass or less.
Here, in the present specification, the "molecular structure" in the description of "100% by mass of the total amount of the structural units excluding the terminal structural units in the molecular structure" is the molecular structure of the polymer which is one aspect of the present invention. Point to. The "terminal structural unit in the molecular structure" refers to a structural unit derived from a polymerization initiator and / or a chain transfer agent used when polymerizing the polymer described later.

From the viewpoint of improving shear stability, improving viscosity index, and solubility in base oil, the polymer has a compound-derived structural unit (b) and carbon number represented by the following general formula (2). Selected from the group consisting of a (meth) acrylate-derived structural unit (c) having 1 to 4 linear alkyl groups and a (meth) acrylate-derived structural unit (d) having 8 to 36 carbon atoms. It is preferable that the copolymer contains one or more structural units.

(In the general formula (2), R ¹ represents a hydrogen atom or a methyl group, R ⁶ represents a linear or branched alkylene group having 2 to 4 carbon atoms, and R ⁷ and R ⁸ are independent carbon atoms. .p indicating the number 2-18 alkyl groups may, when the .p is 2 or more represents an integer of 0 to 20, ^{R 6} existing in plural numbers may be the same or different.)

The preferred embodiments and the like indicated by each reference numeral in the general formula (2) are shown below.
R ¹ preferably represents a methyl group from the viewpoint of improving the viscosity index.
Examples of the linear or branched alkylene group having 2 to 4 carbon atoms indicated by R ⁶ include ethylene group, propane-1,2-diyl group, propane-1,3-diyl group, butane-1,2-diyl group and butane. Examples thereof include -1,3-diyl group, butane-1,4-diyl group, butane-2,2-diyl group and the like, preferably an ethylene group or a propane-1,2-diyl group.
From the viewpoint of the solubility of the obtained polymer in the base oil, p is preferably an integer of 0 to 5, more preferably an integer of 0 to 2, and even more preferably 0.
when p is 2 or more, R ⁶ where there are two or more may be the same or different and the general formula (2) in the - (R 6 ^-O-) aspect of the bond portion between represented by p May be a random join or a block join.
From the viewpoint of improving shear stability and viscosity index, R ⁷ and R ⁸ are preferably alkyl groups having 4 to 16 carbon atoms, more preferably alkyl groups having 4 to 14 carbon atoms, and further preferably 6 to 14 alkyl groups. It shows 14 alkyl groups.
R ⁷ and R ⁸ may be the same or different from each other, and are preferably different from each other.
The alkyl group having 2 to 18 carbon atoms represented by R ⁷ and R ⁸ may be either a linear or branched alkyl group, and is preferably a linear alkyl group.
Further, as an example of a preferable embodiment of the compound represented by the general formula (2), for example, when R ⁷ and R ⁸ are different from each other, for example, R ⁷ is preferably an alkyl having 2 to 14 carbon atoms. It represents a group, more preferably 4 to 14 alkyl groups, even more preferably 8 to 12 alkyl groups. And R ⁸ preferably shows an alkyl group having 2 to 16 carbon atoms, more preferably an alkyl group having 4 to 16 carbon atoms, and further preferably an alkyl group having 10 to 14 carbon atoms.

Examples of specific examples of the compound represented by the general formula (2) include 2-hexyldecyl methacrylate, 2-decyltetradecyl methacrylate, 2-dodecyl hexadecyl methacrylate, and 2-tetradecyl octaoctadecyl methacrylate. And so on. Among the specific examples, the compound represented by the general formula (2) is preferably 2-decyltetradecyl methacrylate, 2-dodecyl hexadecyl methacrylate, or 2-tetradecyl octaoctadecyl methacrylate, more preferably. 2-decyltetradecyl methacrylate, or 2-tetradecyl octa-octadecyl methacrylate, more preferably 2-decyl tetradecyl methacrylate.
Further, the compound represented by the general formula (2), which is the raw material of the structural unit (b), may be used alone or in combination of two or more of the above-mentioned compounds.

The content of the structural unit (b) in the polymer is based on 100% by mass of the total amount of the structural units excluding the terminal structural units in the molecular structure, and is preferably 0 to 95% by mass from the same viewpoint as described above. It is more preferably 0 to 60% by mass, still more preferably 0 to 30% by mass.
When the polymer contains the structural unit (b), the content of the structural unit (b) is based on 100% by mass of the total amount of the structural units excluding the terminal structural units in the molecular structure, and the same viewpoint as described above. Therefore, it is preferably more than 0% by mass and 95% by mass or less, more preferably 5% by mass or more and 60% by mass or less, and further preferably 10% by mass or more and 30% by mass or less.

Examples of the (meth) acrylate having a linear alkyl group having 1 to 4 carbon atoms, which is the raw material of the structural unit (c), include methyl (meth) acrylate, ethyl (meth) acrylate, and n-propyl (meth). Examples thereof include acrylate and n-butyl (meth) acrylate. The (meth) acrylate having a linear alkyl group having 1 to 4 carbon atoms is preferably methyl (meth) acrylate, and more preferably methyl methacrylate.
Further, the (meth) acrylate having a linear alkyl group having 1 to 4 carbon atoms, which is the raw material of the structural unit (c), may be used alone or in combination of two or more from the above-mentioned ones.

The content of the structural unit (c) in the polymer is based on 100% by mass of the total amount of the structural units excluding the terminal structural units in the molecular structure, and is preferably 0 to 70% by mass from the same viewpoint as described above. It is more preferably 10 to 70% by mass, further preferably 20 to 65% by mass, and even more preferably 30 to 65% by mass.

The (meth) acrylate having a linear alkyl group having 8 to 36 carbon atoms, which is the raw material of the structural unit (d), is preferably a (meth) acrylate having a linear alkyl group having 12 to 32 carbon atoms. A (meth) acrylate having a linear alkyl group having 12 to 24 carbon atoms is preferable, and a (meth) acrylate having a linear alkyl group having 12 to 18 carbon atoms is more preferable.

Examples of the (meth) acrylate having a linear alkyl group having 8 to 36 carbon atoms, which is the raw material of the structural unit (d), include n-octyl (meth) acrylate, n-nonyl (meth) acrylate, and n-. Decyl (meth) acrylate, n-undecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, n-pentadecyl (meth) acrylate, n-hexadecyl ( Meta) acrylate, n-heptadecyl (meth) acrylate, n-octadecyl (meth) acrylate, n-nonadecil (meth) acrylate, n-icosyl (meth) acrylate, n-henicocil (meth) acrylate, n-docosyl (meth) Acrylate, n-tricosyl (meth) acrylate, n-tetracosyl (meth) acrylate, n-hexacosyl (meth) acrylate, n-octacocil (meth) acrylate, n-triacontyl (meth) acrylate, n-dotriacyl (meth) acrylate, Examples thereof include n-tetratriacontyl (meth) acrylate and n-hexatriacontyl (meth) acrylate.
Further, the (meth) acrylate having a linear alkyl group having 8 to 36 carbon atoms, which is the raw material of the structural unit (d), may be used alone or in combination of two or more from the above-mentioned ones.

The content of the structural unit (d) in the polymer is based on 100% by mass of the total amount of the structural units excluding the terminal structural units in the molecular structure, and is preferably 0 to 95% by mass from the same viewpoint as described above. It is more preferably 0 to 70% by mass, still more preferably 0 to 60% by mass.
When the polymer contains the structural unit (d), the content of the structural unit (d) is based on 100% by mass of the total amount of the structural units excluding the terminal structural units in the molecular structure, and the same viewpoint as described above. Therefore, it is preferably more than 0% by mass and 95% by mass or less, more preferably 10% by mass or more and 70% by mass or less, further preferably 20% by mass or more and 60% by mass or less, still more preferably 30% by mass or more and 60% by mass or less. is there.

(Other building blocks)
The polymer according to one aspect of the present invention may further contain other structural units in addition to the structural units (a) to (d) as long as the effects of the present invention are not impaired.
As the structural unit other than the structural units (a) to (d), for example, a structural unit derived from an alkyl (meth) acrylate other than the monomer which is a raw material compound constituting the structural units (a) to (d). ; A structural unit derived from a functional group-containing monomer and the like can be mentioned.
Examples of the alkyl (meth) acrylate other than the monomer which is the raw material compound constituting the structural units (a) to (d) include known carbon used as a raw material of a viscosity index improver for a lubricating oil composition. Examples thereof include (meth) acrylates having a branched alkyl group having a number of 1 to 36, (meth) acrylates having an alicyclic alkyl group, and the like.
Further, as the functional group-containing monomer, a known amino group-containing monomer, a quaternary ammonium base-containing monomer, and a nitrile group-containing monomer used as a raw material of a viscosity index improver for a lubricating oil composition. And a nitro group-containing monomer, a hydroxy group-containing monomer, and a carboxy group-containing monomer (however, the raw material compounds constituting the above-mentioned structural units (a) to (d) are excluded).
When the polymer according to one aspect of the present invention contains these other structural units, the above-mentioned compounds used as raw materials for the structural units may be used alone or in combination of two or more.

In the polymer according to one aspect of the present invention, the total content of the structural units (a) to (d) is 100% by mass based on the total amount of the structural units excluding the terminal structural units in the molecular structure, preferably 80% by mass. % Or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, still more preferably 99% by mass or more, and preferably 100% by mass or less.

The content of each structural unit can be calculated from, for example, the blending amount of the monomer as the raw material of each structural unit. Further, when determining whether or not the polymer present in the viscosity index improver composition or the lubricating oil composition described later satisfies the above constitution, for example, the polymer is separated from the lubricating oil composition by a rubber membrane. The components are taken out, and the polymer component is confirmed by a method of identifying the constituent units derived from each raw material by ¹³ C-NMR and further confirming the content of each constituent unit by using thermal decomposition GC-FID. can do.

The polymer according to one aspect of the present invention has a weight average molecular weight (Mw) of preferably 5,000 to 2,000,000. When the weight average molecular weight (Mw) is 5,000 or more, it is preferable from the viewpoint of improving the viscosity index, and when the weight average molecular weight (Mw) is 2,000,000 or less, good shear stability is obtained. It is preferable from the viewpoint of obtaining sex. From this point of view, the weight average molecular weight (Mw) of the polymer is more preferably 10,000 to 1,000,000, still more preferably 15,000 to 700,000, still more preferably 20,000 to 600. It is 000.
Further, for example, when the polymer according to one aspect of the present invention is used as a viscosity index improver for driving system oil, the weight average molecular weight (Mw) of the polymer is preferably 5,000 to 600,000. , More preferably 10,000 to 230,000, even more preferably 12,000 to 150,000.
Among these, for example, gear oil (manual transmission oil, differential oil, etc.), automatic transmission oil (automatic transmission oil, etc.), belt CVT oil, etc., the polymer according to one aspect of the present invention is used as a viscosity index improver. When used, the weight average molecular weight (Mw) of the polymer is preferably 5,000 to 150,000, more preferably 10,000 to 80,000, still more preferably 12,000 to 55,000, and even more preferably. Is between 15,000 and 50,000. Further, for example, when the polymer according to one aspect of the present invention is used as a viscosity index improver in the traction oil (traction drive power transmission oil), the weight average molecular weight (Mw) of the polymer is preferably. It is 10,000 to 600,000, more preferably 12,000 to 230,000, and even more preferably 15,000 to 150,000.
The weight average molecular weight (Mw) is measured by the method described in Examples described later.
Further, the aspect of the copolymer as the component (B) may be, for example, any of a random addition polymer, an alternating copolymer, a graft copolymer, and a block copolymer.

The polymer according to one aspect of the present invention has a PSSI measured by the method described in Examples described later, preferably 5.0 or less, more preferably 4.0 or less, still more preferably 3.0 or less. Even more preferably, it is 2.0 or less. The PSSI means a permanent shear stability index (Permanent Shear Stability Index). The smaller the PSSI, the more stable the polymer is to shear and the less likely it is to decompose.
The lower limit of the PSSI is not particularly limited, but is, for example, 0 or more.

[Method for producing polymer]
The polymer according to one aspect of the present invention can be obtained, for example, by radical polymerization of the above-mentioned monomer as a raw material for each structural unit.
As the polymerization method, conventionally known methods such as a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, a reverse phase suspension polymerization method, a thin film polymerization method, and a spray polymerization method can be used. The solution polymerization method is preferable, and it can be obtained by radical polymerization of the above-mentioned monomer as a raw material of each structural unit in a solvent.
When the polymer according to one aspect of the present invention is produced by solution polymerization, the structural unit (a) is used in a solvent and a polymerization initiator is used, and if necessary, the structural units (b) to (d) are further added. And other constituent units can be obtained by radical polymerization of a monomer as a raw material.

The solvent may be any solvent in which the monomer dissolves, and is an aromatic hydrocarbon solvent such as toluene, xylene, alkylbenzene having 9 to 10 carbon atoms; carbon such as pentane, hexane, heptane, cyclohexane, and octane. An aliphatic hydrocarbon solvent having a number of 5 to 18; an alcohol solvent having 3 to 8 carbon atoms such as 2-propanol, 1-butanol, 2-butanol, and 1-octanol; a ketone solvent such as methyl isobutyl ketone and methyl ethyl ketone; An amide-based solvent such as N, N-dimethylformamide and N-methylpyrrolidone; and a base oil described later; and the like can be used. Among these, the base oil described later is preferable, and among the base oils, mineral oil is more preferable.

Examples of the polymerization initiator include one or more selected from the group consisting of an azo-based initiator, a peroxide-based initiator, a redox-based initiator, and an organic halogen compound initiator. The polymerization initiator used in the polymer according to one aspect of the present invention is preferably one or more selected from azo-based initiators and peroxide-based initiators, and more preferably azo-based initiators and organic peroxides. One or more selected from the above, more preferably an azo-based initiator can be used.
Examples of the azo-based polymerization initiator include 2,2'-azobis (isobutyronitrile) (abbreviation: AIBN), 2,2'-azobis (2-methylbutyronitrile) (abbreviation: AMBN), 2, 2'-azobis (2,4-dimethylvaleronitrile) (abbreviation: ADVN), 4,4'-azobis (4-cyanovaleric acid) (abbreviation: ACVA) and salts thereof (eg, hydrochloride, etc.), dimethyl 2, Examples thereof include 2'-azobisisobutyrate, 2,2'-azobis (2-amidinopropane) hydrochloride, 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide] and the like. ..

Examples of the peroxide-based initiator include inorganic peroxides and organic peroxides.
Examples of the inorganic peroxide include hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate.
Examples of the organic peroxide include benzoyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, succinate peroxide, di (2-ethoxyethyl) peroxydicarbonate, and tert-butylperoxypivalate. , Tert-Hexylperoxypivalate, tert-butylperoxyneoheptanoate, tert-butylperoxyneodecanoate, tert-butylperoxy2-ethylhexanoate, tert-butylperoxyisobutyrate, Examples thereof include tert-amylperoxy2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy2-ethylhexanoate, dibutylperoxytrimethyladipate, and lauryl peroxide.

Redox-based initiators include reducing agents such as alkali metal sulfite or persulfate (for example, ammonium sulfite, ammonium persulfate, etc.), ferrous chloride, ferrous sulfate, ascorbic acid, and alkali metal persulfate. Examples thereof include those composed of a combination with an oxidizing agent such as a salt, ammonium persulfate, hydrogen peroxide, and an organic peroxide.

In the radical polymerization, a known chain transfer agent may be used, if necessary, for the purpose of adjusting physical properties of the polymer such as molecular weight.
Examples of the chain transfer agent include secondary alcohols such as mercaptans, thiocarboxylic acids and isopropanol, amines such as dibutylamine, hypophosphites such as sodium hypophosphite, chlorine-containing compounds and alkylbenzene compounds. ..
Examples of the mercaptans include alkyl groups having 2 to 20 carbon atoms such as n-butyl mercaptan, isobutyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, sec-butyl mercaptan, tert-butyl mercaptan, and tert-dodecyl mercaptan. Examples thereof include alkyl mercaptan compounds having, and hydroxyl group-containing mercaptan compounds such as mercaptoethanol and mercaptopropanol.
Examples of thiocarboxylic acids include thioglycolic acid and thioapple acid.
The amount of the polymerization initiator and chain transfer agent used can be appropriately selected in consideration of the physical properties of the desired polymer (for example, adjustment of the molecular weight).

Examples of the polymerization control method include an adiabatic polymerization method and a temperature control polymerization method. The reaction temperature at the time of polymerization is preferably 30 to 140 ° C, more preferably 50 to 130 ° C, and even more preferably 70 ° C to 120 ° C.
In addition to the method of initiating polymerization by heat, a method of initiating polymerization by irradiating with radiation, an electron beam, ultraviolet rays, or the like can also be adopted. A temperature-controlled solution polymerization method is preferred.
When the copolymerization is carried out, either random addition polymerization or alternate copolymerization may be used, and either graft copolymerization or block copolymerization may be used.

The polymer according to one aspect of the present invention can be suitably used as a viscosity index improver for a lubricating oil composition.
The viscosity index improver according to one aspect of the present invention is made of the above-mentioned polymer, and further, the lubricating oil composition can be obtained by dissolving and diluting it in a diluent to obtain a viscosity index improver composition. It is preferable because it can be easily dissolved in the containing base oil.
As the diluent, a solvent that can be used during the above-mentioned polymerization can be used, preferably a base oil, and more preferably a mineral oil. These diluents may be used alone or in combination of two or more from the above-mentioned ones.
When the viscosity index improver composition comprises the polymer and the diluent, the content of the polymer is preferably 5 to 80% by mass, more preferably 5 to 80% by mass, based on 100% by mass of the total amount of the viscosity index improver composition. Is 20 to 80% by mass, more preferably 30 to 70% by mass.
The content of the diluent is preferably 520 to 95% by mass, more preferably 20 to 80% by mass, and further preferably 30 to 70% by mass, based on 100% by mass of the total amount of the viscosity index improver composition.

[Lubricating oil composition]
The lubricating oil composition according to one aspect of the present invention contains the polymer according to one aspect of the present invention described above and a base oil. When the lubricating oil composition does not contain the polymer which is one aspect of the present invention, the shear stability is inferior.
Since the specific embodiment of the polymer and the preferred embodiment thereof are as described above, the description thereof is omitted here.

<Base oil>
The base oil used in the lubricating oil composition is not particularly limited, and any mineral oil or synthetic oil conventionally used as the base oil of the lubricating oil can be appropriately selected and used.
As the mineral oil, for example, the lubricating oil distillate obtained by vacuum distillation of the atmospheric residual oil obtained by atmospheric distillation of crude oil is subjected to solvent removal treatment; at least one treatment of solvent extraction or hydrocracking. At least one dewaxing treatment for solvent dewaxing or catalytic dewaxing; hydrorefining treatment; one or more treatments, preferably all treatments, and refined oils or mineral oil-based waxes of the opposite sex Examples thereof include oil produced by refining. Of these, oils treated by hydrorefining are preferred.
Examples of the synthetic oil include polyα-olefins such as copolymers such as polybutene, α-olefin homopolymer, and ethylene-α-olefin copolymer; various types such as polyol ester, dibasic acid ester, and phosphoric acid ester. Esters; various ethers such as polyphenyl ethers; polyglycols; alkylbenzenes; alkylnaphthalene; or GTL base oils produced by hydrogenating and dewaxing residual WAX (gast liquid wax) in the GTL process. Can be mentioned.
These base oils may be used alone or in combination of two or more of the above-mentioned ones.
The base oil contained in the lubricating oil composition is a case where the base oil is used as the solvent used when polymerizing the above-mentioned polymer, and the base oil used as the polymerization solvent is used as it is as the lubricating oil. When added to the composition, the base oil used as the polymerization solvent can be regarded as one of the base oils contained in the lubricating oil composition. Similarly, when the viscosity index improver composition according to one aspect of the present invention contains a base oil as a diluent, the base oil used as the diluent is added to the lubricating oil composition as it is. In this case, the base oil used as the diluent can also be regarded as one of the base oils contained in the lubricating oil composition.

The viscosity of the base oil is not particularly limited, but the kinematic viscosity at 100 ° C. is preferably ² to 30 mm ² / s, more preferably ² to 15 mm ² / s, still more preferably ^{2 to 10} mm ² / s, and further. It is preferably ² to 5 mm ² / s. When the 100 ° C. kinematic viscosity is 2 mm ² / s or more, the evaporation loss is small, and when it is 30 mm ² / s or less, the power loss due to the viscous resistance is suppressed, and the fuel consumption improving effect can be obtained.
The viscosity index of the base oil is preferably 50 or more, more preferably 80 or more, still more preferably 100 or more, and even more preferably 105 or more. When the viscosity index of the base oil is in this range, it becomes easy to improve the viscosity characteristics of the lubricating oil composition.
The values of kinematic viscosity and viscosity index at 100 ° C. are measured by the methods described in Examples described later.

The content of the polymer in the lubricating oil composition is preferably 0.01 to 30% by mass, more preferably 0.5 to 25% by mass, and further preferably 1 to 25% by mass.

<Other ingredients>
The lubricating oil composition according to one aspect of the present invention may further contain other components other than the polymer and the base oil, if necessary, as long as the effects of the present invention are not impaired.
Examples of other components include commonly used additives for lubricating oils, and examples of the additives for lubricating oils include metal-based detergents, abrasion resistant agents, ashless dispersants, and polymers other than the above-mentioned polymers. From the group consisting of viscosity index improvers, extreme pressure agents, pour point lowering agents, antioxidants, antifoaming agents, surfactants, anti-emulsifiers, friction modifiers, oiliness improvers, rust inhibitors and metal inactivating agents. One or more selected types can be mentioned.
These lubricant additives may be used alone or in combination of two or more.

The content of each of these additives for lubricating oil can be appropriately adjusted within a range that does not impair the effects of the present invention. The content of each of the additives for lubricating oil is, for example, preferably 0.001 to 15% by mass, more preferably 0.005 to 10% by mass, based on the total amount (100% by mass) of the lubricating oil composition. More preferably, it is 0.01 to 8% by mass.
Further, when the lubricating oil composition of one aspect of the present invention contains these additives for lubricating oil other than the polymer, the total content thereof is based on the total amount (100% by mass) of the lubricating oil composition. It is preferably more than 0% by mass and 30% by mass or less, more preferably 0.001 to 25% by mass, still more preferably 0.001 to 20% by mass, and even more preferably 0.001 to 15% by mass.

(Metal-based cleaning agent)
Examples of the metal-based cleaning agent include organic acid metal salt compounds containing metal atoms selected from alkali metals and alkaline earth metals, and specifically, metal atoms selected from alkali metals and alkaline earth metals. Examples thereof include metal salicylates, metal phenates, and metal sulfonates containing.
In addition, in this specification, "alkali metal" refers to lithium, sodium, potassium, rubidium, cesium, and francium.
The "alkaline earth metal" refers to beryllium, magnesium, calcium, strontium, and barium.
As the metal atom contained in the metal-based cleaning agent, sodium, calcium, magnesium, or barium is preferable, and calcium is more preferable, from the viewpoint of improving the cleanliness at high temperature.

The metal salicylate is preferably a compound represented by the following general formula (3), the metal phenate is preferably a compound represented by the following general formula (4), and the metal sulfonate is preferably the following general formula (5). ) Is preferable.

In the general formulas (3) to (5), M is a metal atom selected from alkali metals and alkaline earth metals, and sodium, calcium, magnesium, or barium is preferable, and calcium is more preferable. Further, ^ME is an alkaline earth metal, preferably calcium, magnesium, or barium, and more preferably calcium. q is the valence of M, which is 1 or 2. R ³¹ and R ³² are independently hydrogen atoms or hydrocarbon groups having 1 to 18 carbon atoms. S represents a sulfur atom. r is an integer of 0 or more, preferably an integer of 0 to 3.
Hydrocarbon groups that can be selected as R ³¹ and R ³² include, for example, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 18 ring-forming carbon atoms, and a ring-forming carbon. Examples thereof include an aryl group having 6 to 18, an alkylaryl group having 7 to 18 carbon atoms, and an arylalkyl group having 7 to 18 carbon atoms.

In one aspect of the present invention, these metal-based cleaning agents may be used alone or in combination of two or more. Among these, one or more selected from calcium salicylate, calcium phenate, and calcium sulfonate are preferable from the viewpoint of improving cleanliness at high temperature and from the viewpoint of solubility in base oil.

In one aspect of the present invention, these metal-based cleaning agents may be any of a neutral salt, a basic salt, a hyperbasic salt, and a mixture thereof.
The total base value of the metal-based cleaning agent is preferably 0 to 600 mgKOH / g.
In one aspect of the present invention, when the metal-based cleaning agent is a basic salt or a hyperbasic salt, the total base value of the metal-based cleaning agent is preferably 10 to 600 mgKOH / g, more preferably. It is 20 to 500 mgKOH / g.
In addition, in this specification, a "base value" is defined as 7. of JIS K2501: 2003 "Petroleum products and lubricating oil-neutralization value test method". It means the base value by the perchloric acid method measured according to.

When the lubricating oil composition of one aspect of the present invention contains a metal-based cleaning agent as another component, the content of the metal-based cleaning agent is preferably based on the total amount (100% by mass) of the lubricating oil composition. It is 0.01 to 10% by mass.
The metal-based cleaning agent may be used alone or in combination of two or more. The suitable total content when two or more kinds are used is also the same as the above-mentioned content.

(Abrasion resistant agent)
Examples of the abrasion resistant agent include sulfur-containing compounds such as zinc dialkyldithiophosphate (ZnDTP), zinc phosphate, disulfides, olefins sulfide, fats and oils sulfide, sulfide esters, thiocarbonates, thiocarbamates, and polysulfides. Phosphate esters, phosphoric acid esters, phosphonic acid esters, and phosphorus-containing compounds such as amine salts or metal salts thereof; thio-sulfuric acid esters, thiophosphate esters, thiophosphonic acid esters, and these. Sulfur and phosphorus-containing abrasion resistant agents such as amine salts or metal salts of the above can be mentioned.
Among these, zinc dialkyldithiophosphate (ZnDTP) is preferable.
When the lubricating oil composition of one aspect of the present invention contains an abrasion resistant agent as another component, the content of the abrasion resistant agent is preferably 0 based on the total amount (100% by mass) of the lubricating oil composition. .05 to 5.0% by mass.
The wear resistant agent may be used alone or in combination of two or more. The suitable total content when two or more kinds are used is also the same as the above-mentioned content.

(Ashes-free dispersant)
Examples of the ashless dispersant include succinimide, benzylamine, succinate ester, and boron-modified products thereof, and alkenyl succinimide and boron-modified alkenyl succinimide are preferable.

Examples of the alkenyl succinimide include alkenyl succinate monoimide represented by the following general formula (i) and alkenyl succinate bisimide represented by the following general formula (ii).
The alkenyl succinimide is a compound represented by the following general formula (i) or (ii), and one or more selected from alcohols, aldehydes, ketones, alkylphenols, cyclic carbonates, epoxy compounds, organic acids and the like. May be used as a modified alkenyl succinimide obtained by reacting the above.
Examples of the boron-modified alkenyl succinimide include boron-modified compounds of the compounds represented by the following general formulas (i) or (ii).

The general formula (i), in ^(ii), R ^{A, R A1} and ^{R A2} are each independently, weight average molecular weight (Mw) of 500 to 3,000 (preferably 1,000 to 3,000) It is an alkenyl group, preferably a polybutenyl group or a polyisobutenyl group.
R ^{B, R B1} and ^{R B2} are each independently an alkylene group having 2 to 5 carbon atoms.
x1 is an integer of 1 to 10, preferably an integer of 2 to 5, and more preferably 3 or 4.
x2 is an integer of 0 to 10, preferably an integer of 1 to 4, more preferably 2 or 3.

In one aspect of the present invention, the ratio [B / N] of the boron atom and the nitrogen atom constituting the boron-modified alkenyl succinimide is preferably 0.5 or more, more preferably 0, from the viewpoint of improving cleanliness. It is 6.6 or more, more preferably 0.8 or more, and even more preferably 0.9 or more.
When the lubricating oil composition of one aspect of the present invention contains an ashless dispersant as another component, the content of the ashless dispersant is based on the total amount (100% by mass) of the lubricating oil composition. , Preferably 0.1 to 20% by mass.

(Viscosity index improver)
Examples of the viscosity index improver other than the polymer include PMA-based polymers such as non-dispersive polyalkyl (meth) acrylate and dispersed polyalkyl (meth) acrylate; olefin-based copolymers (eg, ethylene-propylene copolymer weight). (Combination, etc.), OCP-based such as dispersed olefin-based copolymer; styrene-based copolymer (for example, styrene-diene copolymer, styrene-isoprene copolymer, etc.) and the like.
These viscosity index improvers preferably have a mass average molecular weight (Mw) of 5,000 or more and 1,500,000 or less, and in the case of PMA type, preferably 20,000 or more, more preferably 100,000 or more. It is also preferably 1,000,000 or less, more preferably 800,000 or less. Further, in the case of the OCP system, it is preferably 10,000 or more, more preferably 20,000 or more, and preferably 800,000 or less, more preferably 500,000 or less.
The mass average molecular weight (Mw) is measured, for example, by the method described in Examples described later.
The structure of the viscosity index improver other than the polymer may be a straight chain or a branched chain. In addition, a comb-shaped polymer having a structure having many three-pronged bifurcation points in the main chain having high molecular weight side chains, and a kind of branched polymer in which three or more chain polymers are bonded at one point. It may be a polymer having a specific structure such as a star-shaped polymer having a structure.

Further, as the viscosity index improver other than the polymer, as described above, a polymer having a structure having many three-pronged branch points having linear side chains in the main chain (hereinafter, referred to as “comb-shaped polymer”). May be contained. As such a comb-shaped polymer, for example, a polymer having at least a structural unit derived from a macromonomer having a polymerizable functional group such as a metaacryloyl group, an acryloyl group, an ethenyl group, a vinyl ether group, and an allyl group is preferable. Here, the structural unit corresponds to a "linear side chain".
More specifically, various vinyls such as alkyl (meth) acrylate, nitrogen atom-containing system, halogen element-containing system, hydroxyl group-containing system, aliphatic hydrocarbon system, alicyclic hydrocarbon system, aromatic hydrocarbon system, etc. A copolymer having a side chain containing a structural unit derived from the macromonomer having a polymerizable functional group is preferably used with respect to a main chain containing a structural unit derived from a polymer.

The number average molecular weight (Mn) of the macromonomer is preferably 200 or more, more preferably 300 or more, still more preferably 400 or more, and preferably 100,000 or less, more preferably 50,000 or less, still more preferably. It is 10,000 or less.
Further, the mass average molecular weight (Mw) of the comb-shaped polymer is preferably 1,000 or more, more preferably 5,000 or more, still more preferably 50,000 or more, and from the viewpoint of improving fuel efficiency. It is preferably 1,000,000 or less, more preferably 800,000 or less, still more preferably 700,000 or less. The molecular weight distribution (Mw / Mn) is preferably 6 or less, more preferably 5.6 or less, still more preferably 5 or less, and the lower limit is not particularly limited, but is preferably 1.01 or more, more preferably 1. It is 0.05 or more, more preferably 1.10 or more, and even more preferably 1.50 or more.

The viscosity index improver other than the polymer is preferably a polyalkyl (meth) acrylate having a PSSI of 30 or less.
The monomer constituting the polyalkyl (meth) acrylate is an alkyl (meth) acrylate, preferably a linear alkyl group having 1 or more and 18 or less carbon atoms or a branched alkyl (meth) acrylate having 3 or more and 34 or less carbon atoms. Is.
The polystyrene-equivalent mass average molecular weight (Mw) of the polyalkyl (meth) acrylate is preferably 10,000 or more and 1 million or less, and more preferably 30,000 or more and 500,000 or less. By setting the mass average molecular weight of the polyalkyl (meth) acrylate within this range, it becomes easy to adjust the SSI value to 30 or less.
The mass average molecular weight (Mw) is measured by the method described in Examples described later.

These viscosity index improvers may be used alone or in combination of two or more.
Further, the viscosity index improver contains, for example, a polymer other than the polymer according to one aspect of the present invention as a resin component, but usually, handleability and solubility in the above-mentioned base oil are taken into consideration. However, the resin component containing the polymer is often marketed in the form of a solution diluted with a diluting oil such as mineral oil. The resin concentration of the viscosity index improver is usually 10% by mass or more and 80% by mass or less based on the total amount of the viscosity index improver.
When a viscosity index improver composed of a polymer other than the polymer according to one aspect of the present invention is used, the content of the viscosity index improver is the total amount of the lubricating oil composition as the content in terms of resin content. On a (100% by mass) basis, it is preferably 0.2% by mass or more, more preferably 0.3% by mass or more, further preferably 0.4% by mass or more, and preferably 4.0% by mass or less. It is more preferably 3.0% by mass or less, still more preferably 2.0% by mass or less.

(Extreme pressure agent)
Examples of the extreme pressure agent include sulfur-based extreme pressure agents such as sulfides, sulfoxides, sulfones and thiophosphinates, halogen-based extreme pressure agents such as chlorinated hydrocarbons, and organometallic extreme pressure agents. Be done. Further, among the above-mentioned wear resistant agents, a compound having a function as an extreme pressure agent can also be used.
In one aspect of the present invention, these extreme pressure agents may be used alone or in combination of two or more.
When the lubricating oil composition of one aspect of the present invention contains an extreme pressure agent as another component, the content of the extreme pressure agent is preferably 0 based on the total amount (100% by mass) of the lubricating oil composition. .1 to 10% by mass.

(Antioxidant)
As the antioxidant, any known antioxidant that has been conventionally used as an antioxidant for lubricating oils can be appropriately selected and used. For example, amine-based antioxidants and phenol-based antioxidants can be used. Examples thereof include antioxidants, molybdenum-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants.
Examples of the amine-based antioxidant include diphenylamine and diphenylamine-based antioxidants such as alkylated diphenylamine having an alkyl group having 3 to 20 carbon atoms; α-naphthylamine, phenyl-α-naphthylamine, and alkyl having 3 to 20 carbon atoms. Examples thereof include naphthylamine-based antioxidants having a group such as substituted phenyl-α-naphthylamine; and the like.
Examples of the phenolic antioxidant include 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, and 2,6-di-tert-butyl-4-ethylphenol. Monophenolic antioxidants such as isooctyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate and octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate Agents; diphenolic antioxidants such as 4,4'-methylenebis (2,6-di-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol); hinderedphenols Antioxidants; etc.
Examples of the molybdenum-based antioxidant include a molybdenum amine complex formed by reacting molybdenum trioxide and / or molybdic acid with an amine compound.
Examples of the sulfur-based antioxidant include dilauryl-3,3'-thiodipropionate and the like.
Examples of the phosphorus-based antioxidant include phosphite and the like.
In one aspect of the present invention, these antioxidants can be contained alone or in any combination of two or more, preferably phenolic antioxidants and / or amine antioxidants.
When an antioxidant is contained as another component in the lubricating oil composition of one aspect of the present invention, the content of the antioxidant is preferably 0 based on the total amount (100% by mass) of the lubricating oil composition. .05-7% by mass.

(Pour point depressant)
Examples of the flow point lowering agent include an ethylene-vinyl acetate copolymer, a condensate of chlorinated paraffin and naphthalene, a condensate of chlorinated paraffin and phenol, and a polymethacrylate type (PMA type; polyalkyl (meth)). (Acrylate, etc.), polyvinyl acetate, polybutene, polyalkylstyrene, etc., and polymethacrylate-based polymethacrylates are preferably used. These pour point lowering agents may be used alone or in combination of two or more.
When the lubricating oil composition of one aspect of the present invention contains a pour point lowering agent as another component, the content of the pour point lowering agent is preferably based on the total amount (100% by mass) of the lubricating oil composition. Is 0.01 to 10% by mass.

(Defoamer)
Examples of the defoaming agent include silicone oils such as dimethylpolysiloxane, fluorosilicone oils and fluoroalkyl ethers. These antifoaming agents may be used alone or in combination of two or more.
When the lubricating oil composition of one aspect of the present invention contains a defoaming agent as another component, the content of the defoaming agent is preferably 0 based on the total amount (100% by mass) of the lubricating oil composition. .05 to 5% by mass.

(Surfactant or emulsifier)
Examples of the surfactant or anti-emulsifier include polyalkylene glycol-based nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether and polyoxyethylene alkyl naphthyl ether. These surfactants or anti-emulsifiers can be contained alone or in any combination of two or more.
When a surfactant or an anti-emulsifier is contained as another component in the lubricating oil composition of one aspect of the present invention, the content of the surfactant or the anti-emulsifier is independently the total amount of the lubricating oil composition ( Based on 100% by mass), it is preferably 0.01 to 3% by mass.

(Friction modifier)
Examples of the friction modifier include molybdenum-based friction modifiers such as molybdenum dithiocarbamate (MoDTC), molybdenum dithiophosphate (MoDTP), and amine salts of molybthenoic acid; alkyl groups or alkenyl groups having 6 to 30 carbon atoms are contained in the molecule. Ash-free friction modifiers such as aliphatic amines, fatty acid esters, fatty acid amides, fatty acids, aliphatic alcohols, and aliphatic ethers having at least one; fats and oils, amines, amides, sulfide esters, phosphate esters, phosphite esters. , Phosphate ester amine salt and the like.
When a friction modifier is contained as another component in the lubricating oil composition of one aspect of the present invention, the content of the friction modifier is preferably 0 based on the total amount (100% by mass) of the lubricating oil composition. .05-4% by mass.

(Oil improver)
Examples of the oiliness improver include aliphatic saturated or 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. , Fatty acid saturated or unsaturated monoalcohols such as oleic acid; aliphatic saturated or unsaturated monoamines such as stearylamine and oleylamine; aliphatic saturated or unsaturated monocarboxylic acid amides such as laurate amide and oleic acid amide; glycerin, Partial esters of polyvalent alcohols such as sorbitol and aliphatic saturated or unsaturated monocarboxylic acids; and the like.
When the lubricating oil composition of one aspect of the present invention contains an oily improving agent as another component, the content of the oily improving agent is preferably 0 based on the total amount (100% by mass) of the lubricating oil composition. It is 0.01 to 5% by mass.

(anti-rust)
Examples of the rust preventive include fatty acids, alkenyl succinic acid half esters, fatty acid salts, alkyl sulfonates, polyhydric alcohol fatty acid esters, fatty acid amines, oxidized paraffins, alkyl polyoxyethylene ethers and the like.
When the lubricating oil composition of one aspect of the present invention contains a rust inhibitor as another component, the content of the rust inhibitor is preferably 0 based on the total amount (100% by mass) of the lubricating oil composition. .01 to 3% by mass.

(Metal inactivating agent)
Examples of the metal inactivating agent include benzotriazole-based compounds, tolyltriazole-based compounds, thiazizol-based compounds, imidazole-based compounds, pyrimidine-based compounds and the like.
When a metal inactivating agent is contained as another component in the lubricating oil composition of one aspect of the present invention, the content of the metal inactivating agent is based on the total amount (100% by mass) of the lubricating oil composition. , Preferably 0.01 to 5% by mass.

[Manufacturing method of lubricating oil composition]
In the method for producing a lubricating oil composition according to an embodiment of the present invention, the polymer and the base oil according to the above-mentioned aspect of the present invention are blended.
Further, in the production method, other components other than the polymer and the base oil may be further blended, if necessary.
Each of the polymer, the base oil, and the other components is the same as that described for the lubricating oil composition, and the preferred embodiments thereof are also the same, and the lubricating oil composition obtained by the production method is also the same. Since it is as described above, the description thereof will be omitted.
In the production method, the polymer and the base oil, and other components added as necessary may be blended by any method, and the method is not limited.

[Use of lubricating oil composition]
As described above, the compound according to the embodiment of the present invention has an excellent effect of improving the viscosity index and has excellent shear stability.
Therefore, the lubricating oil composition according to the embodiment of the present invention containing the compound according to the embodiment of the present invention includes, for example, gear oil (manual transmission oil, differential oil, etc.), automatic transmission oil (automatic transmission). Oil, etc.), stepless transmission oil (belt CVT oil, toroidal CVT oil, etc.), power steering oil, shock absorber oil, drive system oil such as electric motor oil; for gasoline engine, diesel engine, gas engine, etc. Internal engine (engine) oil; hydraulic hydraulic oil; turbine oil; compressor oil; fluid bearing oil; rolling bearing oil; etc., which can be suitably used for various purposes, and is filled in the equipment used in each of these applications. , Can be suitably used as a lubricating oil for lubricating between each component related to the device.
Further, among these, due to the above-mentioned characteristics, it is more suitable as a lubricating oil composition used in a wider temperature range, and for example, transportation equipment such as automobiles such as two-wheeled vehicles and four-wheeled vehicles, trains, ships, and airplanes. Lubricants for drive system equipment such as gears, automatic transmissions, continuously variable transmissions, shock absorbers, power steering, electric motors, etc. mounted on generators and various machine tools; gasoline engines, diesel engines, gas engines, etc. It can be more preferably used as a lubricating oil for an internal combustion engine.

[Lubricating method using lubricating oil composition]
As described in the above-mentioned applications, as a lubrication method using the lubricating oil composition according to the embodiment of the present invention, the lubricating oil composition is preferably filled in the apparatus used in each of the above-mentioned applications. , A method of lubricating between each part related to each device.
Then, as a lubrication method using the lubricating oil composition according to the embodiment of the present invention, the lubricating oil composition is more preferably used, for example, automobiles such as two-wheeled vehicles and four-wheeled vehicles, trains, ships, airplanes and the like. Drive system equipment such as gears, automatic transmissions, continuously variable transmissions, shock absorbers, power steering, electric motors, etc. mounted on transportation equipment, generators, and various machine tools; gasoline engines, diesel engines, gas engines, etc. An internal combustion engine; or the like, and lubricated between the parts related to the drive system equipment or between the parts related to the internal combustion engine.

[Drive system equipment using lubricating oil composition]
Another embodiment of the present invention includes a drive system device using the lubricating oil composition, and preferably a drive system device using the lubricating oil composition as the drive system oil. Examples of the drive system equipment include gears, automatic transmissions, and continuously variable transmissions mounted on automobiles such as two-wheeled vehicles and four-wheeled vehicles, transportation equipment such as trains, ships, and airplanes, generators, and various machine tools. Machines, shock absorbers, power steering, electric motors, etc.

[Internal combustion engine using lubricating oil composition]
Another embodiment of the present invention includes an internal combustion engine using the lubricating oil composition, and preferably an internal combustion engine (engine) using the lubricating oil composition as an engine oil. Examples of the internal combustion engine include a gasoline engine, a diesel engine, a gas engine, and the like mounted on transportation equipment such as automobiles such as two-wheeled vehicles and four-wheeled vehicles, trains, ships, and airplanes.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these examples.

In the present specification, the physical properties of the raw materials used in each Example and each Comparative Example and the compounds, polymers, and lubricating oil compositions of each Example and each Comparative Example are measured according to the following procedure. Is.
< ^{1 1} H-NMR>
The compounds obtained in Synthesis Examples 1 to 3 were identified by ¹ H-NMR measurement under the following conditions.
The measurement was performed using the product name "JNM-AL400" (400 MHz) manufactured by JEOL Ltd.
The measurement sample was dissolved in deuterated chloroform (CDCl ₃ ), and the measurement was carried out under the conditions of normal temperature (25 ° C.) and the number of integrations: 8 times. Tetramethylsilane (TMS) was used as a reference substance.
<Kinematic viscosity (100 ° C kinematic viscosity)>
It is a value measured using a glass capillary viscometer according to JIS K2283: 2000.
<Viscosity index>
It is a value calculated in accordance with JIS K2283: 2000.
<Weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn)>
Waters "1515 Isocratic HPLC Pump", "2414 Differential Refractometer (RI) Detector", Tosoh's column "TSKgradvolume SuperHZ-L", and "TSKSuperMultipore HZ-M" 2 The book was attached in this order from the upstream side, measured under the conditions of measurement temperature: 40 ° C., mobile phase: tetrahydrofuran, flow velocity: 0.35 ml / min, sample concentration 1.0 mg / ml, and determined by standard polystyrene conversion.
<Permanent Shear Stability Index (PSSI)>
PSSI indicates the decrease in viscosity due to shearing derived from the polymer as a percentage, and was calculated by the following formula defined by ASTM D6022-06 (2012).

In the calculation formula, Kv ₀ is a value of 100 ° C. kinematic viscosity of a mixture obtained by adding a polymer to a base oil. Kv ₁ is a mixture of base oil and polyalkyl (meth) acrylate, which has a kinematic viscosity of 100 ° C. measured in accordance with JASO M347-95 "Automatic Transmission Oil Shear Stability Test Method" (Sonic Ultrasound). The value. Kv _oil is a value of 100 ° C. kinematic viscosity of the base oil.

[Synthesis of compound represented by general formula (1)]
Among the monomers shown in Table 1 below, the methods for synthesizing each compound abbreviated as "(G8) 2MA", "(G16) 2MA", and "(G24) 2MA" are described in Synthesis Examples 1 to 3 below, respectively. Shown in.

<Synthesis Example 1: Synthesis of (G8) 2MA>
(Method for synthesizing glycerin diether)
A four-necked flask equipped with a thermometer, a cooling tube, and a dropping funnel was charged with 45 g of 2-ethyl-1-hexanol, 22 g of sodium hydroxide, and 6 g of tetrabutylammonium bromide.
In a dropping funnel, 59 g of 2-ethylhexyl glycidyl ether was slowly dropped in an ice bath, and after the dropping was completed, the temperature was raised to 60 ° C. for reaction.
After completion of the reaction, the mixture was diluted with ethyl acetate, washed 3 times with ion-exchanged water, dehydrated with magnesium sulfate, filtered, and then the light component was distilled off with an evaporator set at 40 ° C. Then, it was purified by silica gel column chromatography to obtain 1,3-bis (2-ethylhexoxy) propan-2-ol.

((G8) 2MA synthesis method)
A four-necked flask equipped with a thermometer, a cooling tube, and a dropping funnel was charged with 14 g of the 1,3-bis (2-ethylhexoxy) propan-2-ol, 5 g of triethylamine, and 50 g of dichloromethane as a solvent.
In a dropping funnel, 5 g of methacryloyl chloride was slowly dropped in an ice bath, and after the dropping was completed, the temperature was raised to room temperature (23 ° C.) for reaction.
After completion of the reaction, the mixture was washed 3 times with ion-exchanged water, dehydrated with magnesium sulfate, filtered, and then the light component was distilled off with an evaporator set at 40 ° C. Then, it was purified by silica gel column chromatography to obtain 2- (2-ethylhexoxy) -1- (2-ethylhexoxymethyl) ethyl methacrylate (abbreviation in the present specification: "(G8) 2MA"). The ¹ H-NMR analysis result chart of the obtained compound is shown in FIG.
In the obtained compound (G8) 2MA, in the above general formula (1), R ¹ is an methyl group, R ² and R ⁴ are independently ethyl groups, and R ³ and R ⁵ are independently n-butyl. It is a group and is a compound represented by 1 for m and 1 for n.

<Synthesis Example 2: Synthesis of (G16) 2MA>
(Method for synthesizing glycerin diether)
A four-necked flask equipped with a thermometer, a cooling tube, and a dropping funnel was charged with 242 g of 2-hexyl-1-decanol, 64 g of sodium hydroxide, and 16 g of tetrabutylammonium bromide.
With a dropping funnel, 95 g of epichlorohydrin was slowly dropped in an ice bath, and after the dropping was completed, the temperature was raised to 60 ° C. for reaction.
After completion of the reaction, the mixture was diluted with ethyl acetate, washed 3 times with ion-exchanged water, dehydrated with magnesium sulfate, filtered, and then the light component was distilled off with an evaporator set at 40 ° C. Then, it was purified by silica gel column chromatography to obtain 1,3-bis (2-hexyldecoxy) propan-2-ol.

((G16) 2MA synthesis method)
In a four-necked flask equipped with a thermometer, a cooling tube, and a dropping funnel, 134 g of the above 1,3-bis (2-hexyldecoxy) propan-2-ol, 28 g of triethylamine, and 300 g of dichloromethane as a solvent were charged. It is.
With a dropping funnel, 26 g of methacryloyl chloride was slowly dropped in an ice bath, and after the dropping was completed, the temperature was raised to room temperature (23 ° C.) for reaction.
After completion of the reaction, the mixture was washed 3 times with ion-exchanged water, dehydrated with magnesium sulfate, filtered, and then the light component was distilled off with an evaporator set at 40 ° C. Then, purification is performed by silica gel column chromatography to obtain 2- (2-hexyldecoxy) -1- (2-hexyldecoxymethyl) ethyl methacrylate (abbreviation in the present specification: "(G16) 2MA"). It was. The ¹ H-NMR analysis result chart of the obtained compound is shown in FIG.
In the obtained compound (G16) 2MA, in the above general formula (1), R ¹ is a methyl group, R ² and R ⁴ are independently n-hexyl groups, and R ³ and R ⁵ are independently n. -A compound which is an octyl group and whose m is 1 and n is 1.

<Synthesis Example 3: Synthesis of (G24) 2MA>
(Method for synthesizing glycerin diether)
A four-necked flask equipped with a thermometer, a cooling tube, and a dropping funnel was charged with 232 g of 2-decyltetradecanol, 40 g of sodium hydroxide, and 10 g of tetrabutylammonium bromide.
With a dropping funnel, 50 g of epichlorohydrin was slowly dropped in an ice bath, and after the dropping was completed, the temperature was raised to 60 ° C. for reaction.
After completion of the reaction, the mixture was diluted with ethyl acetate, washed 3 times with ion-exchanged water, dehydrated with magnesium sulfate, filtered, and then the light component was distilled off with an evaporator set at 40 ° C. Then, it was purified by silica gel column chromatography to obtain 1,3-bis (2-decyltetradecoxy) propan-2-ol.

((G24) 2MA synthesis method)
In a four-necked flask equipped with a thermometer, a cooling tube, and a dropping funnel, 8.1 g of the above 1,3-bis (2-decyltetradecoxy) propan-2-ol, 1.2 g of triethylamine, and as a solvent. 20 g of dichloromethane was charged.
With a dropping funnel, 1.2 g of methacryloyl chloride was slowly dropped in an ice bath, and after the dropping was completed, the temperature was raised to room temperature (23 ° C.) for reaction.
After completion of the reaction, the mixture was washed 3 times with ion-exchanged water, dehydrated with magnesium sulfate, filtered, and then the light component was distilled off with an evaporator set at 40 ° C. Then, it is purified by silica gel column chromatography to obtain 2- (2-decyltetradecoxy) -1- (2-decyltetradecoxymethyl) ethyl methacrylate (abbreviation in the present specification: "(G24) 2MA"). Got The ¹ H-NMR analysis result chart of the obtained compound is shown in FIG.
In the obtained compound (G24) 2MA, in the above general formula (1), R ¹ is a methyl group, R ² and R ⁴ are independently n-decyl groups, and R ³ and R ⁵ are independently n. -A compound represented by a dodecyl group in which m is 1 and n is 1.

[Polymerization of polymer and preparation of lubricating oil composition]
The abbreviations for each component shown in Table 1 below represent the following compounds.
(Polymer)
"(G8) 2MA": 2- (2-ethylhexoxy) -1- (2-ethylhexoxymethyl) ethyl methacrylate- "(G16) 2MA": 2- (2-hexyldecoxy) -1- (2) -Hexyldecoxymethyl) ethyl methacrylate "(G24) 2MA": 2- (2-decyltetradecoxy) -1- (2-decyltetradecoxymethyl) ethyl methacrylate "G16MA": 2-hexyldecyl methacrylate -"G24MA": 2-decyltetradecyl methacrylate-"MMA": methyl methacrylate- "C18MA": n-octadecyl methacrylate (radical polymerization initiator)
-"ADVN": 2,2'-azobis (2,4-dimethylvaleronitrile)
-"AMBN": 2,2'-azobis (2-methylbutyronitrile)
(Chain transfer agent)
-"DM": n-dodecyl mercaptan (base oil for polymerization solvent)
-"Mineral oil": Mineral oil having a kinematic viscosity of 100 ° C. = 2.174 mm ² / s and a viscosity index of 109 was used.

<Example 1>
Mineral oil was charged as a polymerization solvent in the amount shown in Table 1 below into a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, a dropping funnel and a nitrogen blowing tube.
In another glass beaker, each of the monomers shown in Table 1 below was charged as a monomer in the blending amount shown in Table 1 below, and ADVN was set to 0 with respect to 100 parts by mass of the total amount of the monomer. A monomer-containing solution was prepared by charging .69 parts by mass, AMBN (0.19 parts by mass), and DM (0.94 parts by mass), mixing and dissolving at room temperature (23 ° C.).
The obtained monomer-containing solution was charged into the dropping funnel of the reaction vessel, nitrogen substitution was performed in the gas phase portion in the reaction vessel, and then the monomer-containing solution in the dropping funnel was placed in the dropping funnel at 85 ° C. in a closed state for 2 hours. The whole amount was dropped at a constant rate. 45 minutes and 90 minutes after the completion of the dropping, ADVN was further added in an amount of 0.69 parts by mass and 0.69 parts by mass with respect to 100 parts by mass of the total amount of the polymer, respectively, and the temperature was 85 ° C. for another 90 minutes. To obtain a viscosity index improver composition (A-1) containing the polymer A1 shown in Table 1 below.
The obtained viscosity index improver composition (A-1) was added to the base oil (A-1) so that the 100 ° C. kinematic viscosity of the lubricating oil composition was 5.0 mm ² / s and the amount was added as shown in Table 2 below. It was dissolved in 100 ° C. kinematic viscosity = 2.174 mm ² / s, viscosity index = 109 mineral oil) to obtain a lubricating oil composition (CA-1).
Each property of the obtained lubricating oil composition (CA-1) was evaluated by the method described above. The results obtained are shown in Table 2 below.

<Example 2>
Mineral oil was charged as a polymerization solvent in the amount shown in Table 1 below into a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, a dropping funnel and a nitrogen blowing tube.
In another glass beaker, each of the monomers shown in Table 1 below was charged as a monomer in the blending amount shown in Table 1 below, and ADVN was set to 0 with respect to 100 parts by mass of the total amount of the monomer. A monomer-containing solution was prepared by charging .69 parts by mass, AMBN (0.19 parts by mass), and DM (0.94 parts by mass), mixing and dissolving at room temperature (23 ° C.).
The obtained monomer-containing solution was charged into the dropping funnel of the reaction vessel, nitrogen substitution was performed in the gas phase portion in the reaction vessel, and then the monomer-containing solution in the dropping funnel was placed in the dropping funnel at 85 ° C. in a closed state for 2 hours. The whole amount was dropped at a constant rate. 45 minutes and 90 minutes after the completion of the dropping, ADVN was further added in an amount of 0.69 parts by mass and 0.69 parts by mass with respect to 100 parts by mass of the total amount of the polymer, respectively, and the temperature was 85 ° C. for another 90 minutes. To obtain a viscosity index improver composition (A-2) containing the polymer A2 shown in Table 1 below.
The obtained viscosity index improver composition (A-2) was added to the base oil (A-2) so that the 100 ° C. kinematic viscosity of the lubricating oil composition was 5.0 mm ² / s and the amount was added as shown in Table 2 below. It was dissolved in 100 ° C. kinematic viscosity = 2.174 mm ² / s, viscosity index = 109 mineral oil) to obtain a lubricating oil composition (CA-2).
Each property of the obtained lubricating oil composition (CA-2) was evaluated by the method described above. The results obtained are shown in Table 2 below.

<Example 3>
Mineral oil was charged as a polymerization solvent in the amount shown in Table 1 below into a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, a dropping funnel and a nitrogen blowing tube.
In another glass beaker, each of the monomers shown in Table 1 below was charged as a monomer in the blending amount shown in Table 1 below, and ADVN was set to 0 with respect to 100 parts by mass of the total amount of the monomer. A monomer-containing solution was prepared by charging .67 parts by mass of AMBN, 0.20 parts by mass of AMBN, and 0.67 parts by mass of DM, mixing and dissolving at room temperature (23 ° C.).
The obtained monomer-containing solution was charged into the dropping funnel of the reaction vessel, nitrogen substitution was performed in the gas phase portion in the reaction vessel, and then the monomer-containing solution in the dropping funnel was placed in the dropping funnel at 85 ° C. in a closed state for 2 hours. The whole amount was dropped at a constant rate. 45 minutes and 90 minutes after the completion of the dropping, ADVN was further added in an amount of 0.67 parts by mass and 0.67 parts by mass with respect to 100 parts by mass of the total amount of the polymer, respectively, and the temperature was 85 ° C. for another 90 minutes. To obtain a viscosity index improver composition (A-3) containing the polymer A3 shown in Table 1 below.
The obtained viscosity index improver composition (A-3) was added to the base oil (A-3) so that the 100 ° C. kinematic viscosity of the lubricating oil composition was 5.0 mm ² / s and the amount was added as shown in Table 2 below. It was dissolved in 100 ° C. kinematic viscosity = 2.174 mm ² / s, viscosity index = 109 mineral oil) to obtain a lubricating oil composition (CA-3).
Each property of the obtained lubricating oil composition (CA-3) was evaluated by the above-mentioned method. The results obtained are shown in Table 2 below.

<Comparative example 1>
Mineral oil was charged as a polymerization solvent in the amount shown in Table 1 below into a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, a dropping funnel and a nitrogen blowing tube.
In another glass beaker, each of the monomers shown in Table 1 below was charged as a monomer in the blending amount shown in Table 1 below, and ADVN was set to 0 with respect to 100 parts by mass of the total amount of the monomer. A monomer-containing solution was prepared by charging .48 parts by mass and 0.95 parts by mass of DM, mixing and dissolving at room temperature (23 ° C.).
The obtained monomer-containing solution was charged into the dropping funnel of the reaction vessel, nitrogen substitution was performed in the gas phase portion in the reaction vessel, and then the monomer-containing solution in the dropping funnel was placed in the dropping funnel at 85 ° C. in a closed state for 2 hours. The whole amount was dropped at a constant rate. After 45 minutes and 90 minutes from the end of the dropping, ADVN was further added in parts of 0.48 parts by mass and 0.48 parts by mass with respect to 100 parts by mass of the total amount of the polymer, respectively, and the temperature was 85 ° C. for another 90 minutes. To obtain a viscosity index improver composition (X-1) containing the polymer X1 shown in Table 1 below.
The obtained viscosity index improver composition (X-1) was added to the base oil so that the 100 ° C. kinematic viscosity of the lubricating oil composition was 5.0 mm ² / s and the amount was added as shown in Table 2 below. It was dissolved in 100 ° C. kinematic viscosity = 2.174 mm ² / s, viscosity index = 109 mineral oil) to obtain a lubricating oil composition (CX-1).
Each property of the obtained lubricating oil composition (CX-1) was evaluated by the above-mentioned method. The results obtained are shown in Table 2 below.

<Comparative example 2>
Mineral oil was charged as a polymerization solvent in the amount shown in Table 1 below into a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, a dropping funnel and a nitrogen blowing tube.
In another glass beaker, each of the monomers shown in Table 1 below was charged as a monomer in the blending amount shown in Table 1 below, and ADVN was set to 0 with respect to 100 parts by mass of the total amount of the monomer. A monomer-containing solution was prepared by charging .48 parts by mass and 0.95 mass of DM, mixing and dissolving at room temperature (23 ° C.).
The obtained monomer-containing solution was charged into the dropping funnel of the reaction vessel, nitrogen substitution was performed in the gas phase portion in the reaction vessel, and then the monomer-containing solution in the dropping funnel was placed in the dropping funnel at 85 ° C. in a closed state for 2 hours. The whole amount was dropped at a constant rate. 45 minutes and 90 minutes after the completion of the dropping, ADVN was further added in an amount of 0.48 parts by mass and 0.48 parts by mass with respect to 100 parts by mass of the total amount of the polymer, respectively, and the temperature was 85 ° C. for another 90 minutes. To obtain a viscosity index improver composition (X-2) containing the polymer X2 shown in Table 1 below.
The obtained viscosity index improver composition (X-2) was added to the base oil so that the kinematic viscosity at 100 ° C. of the lubricating oil composition was 5.0 mm ² / s and the amount was added as shown in Table 2 below. It was dissolved in 100 ° C. kinematic viscosity = 2.174 mm ² / s, viscosity index = 109 mineral oil) to obtain a lubricating oil composition (CX-2).
Each property of the obtained lubricating oil composition (CX-2) was evaluated by the above-mentioned method. The results obtained are shown in Table 2 below.

As shown in Table 2, the lubricating oil compositions (CA-1) to (CA-3) of Examples 1 to 3 are polymers of the compound according to the present invention. It was confirmed that the viscosity index was improved because it contained.
Then, the polymers A1 to A3 contained in the lubricating oil compositions (CA-1) to (CA-3) of Examples 1 to 3 are the lubricating oil compositions (CX-1) and (CX) of Comparative Examples 1 and 2. It was confirmed that the PSSI value was smaller and the shear stability was excellent as compared with the polymers X1 and X2 contained in -2).
Therefore, it was confirmed that the polymer according to one aspect of the present invention is suitable as a viscosity index improver for a lubricating oil composition.
Further, since the lubricating oil composition according to one aspect of the present invention contains the polymer according to one aspect of the present invention, it was confirmed that the lubricating oil composition is excellent in shear stability.

As described above, the polymer according to one embodiment of the present invention can be suitably used as a viscosity index improver for a lubricating oil composition. Then, the novel compound according to one embodiment of the present invention, which is the raw material monomer of the polymer, can be suitably used as the monomer for the polymer. Therefore, the novel compound according to one embodiment of the present invention can be suitably used as a monomer used as a raw material of a polymer serving as a viscosity index improver for a lubricating oil composition.
Moreover, since the lubricating oil composition according to one embodiment of the present invention contains the polymer according to one embodiment of the present invention, it is a lubricating oil composition having excellent shear stability. Therefore, for example, as described above, it is suitable as a lubricating oil composition used in a wide temperature range such as a driving system oil and a lubricating oil for an internal combustion engine.

Claims (8)

The compound represented by the general formula (1) below.

(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 2 to 18 carbon atoms. n represents an integer of 1 to 10 independently of each other.) The compound according to claim 1, which is a monomer constituting a polymer used as a viscosity index improver for a lubricating oil composition. A polymer containing a structural unit (a) derived from a compound represented by the following general formula (1).

(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 2 to 18 carbon atoms. n represents an integer of 1 to 10 independently of each other.) Further, a structural unit (b) derived from a compound represented by the following general formula (2), a structural unit (c) derived from a (meth) acrylate having a linear alkyl group having 1 to 4 carbon atoms, and 8 to 36 carbon atoms. The polymer according to claim 3, which is a copolymer containing at least one structural unit selected from the group consisting of the structural unit (d) derived from the (meth) acrylate having a linear alkyl group of.

(In the general formula (2), R ¹ represents a hydrogen atom or a methyl group, R ⁶ represents a linear or branched alkylene group having 2 to 4 carbon atoms, and R ⁷ and R ⁸ are independent carbon atoms. .p indicating the number 2-18 alkyl groups may, when the .p is 2 or more represents an integer of 0 to 20, ^{R 6} existing in plural numbers may be the same or different.) The polymer according to claim 3 or 4, wherein the content of the structural unit (a) is 5 to 70% by mass based on 100% by mass of the total amount of the structural units excluding the terminal structural units in the molecular structure. The polymer according to any one of claims 3 to 5, which has a weight average molecular weight of 5,000 to 2,000,000. The polymer according to any one of claims 3 to 6, which is used as a viscosity index improver for a lubricating oil composition. A lubricating oil composition containing the polymer according to any one of claims 3 to 7 and a base oil.