JP2001164280A - Lubricating oil additive and lubricating oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-viscosity low-viscosity lubricating base oil which can be expected to have an effect of adding a small amount to a high-viscosity index lubricating base oil which has little effect in the prior art and a solvent-refined lubricating base oil. Development of additives for lowering pour point and / or lubricating oil compositions containing the same. SOLUTION: An additive characterized by copolymerizing 5 to 15% by mass of an alkyl methacrylate having 1 to 4 carbon atoms of an alkyl group and an alkyl methacrylate having 5 to 22 carbon atoms of an alkyl group, and containing the additive. A lubricating oil composition is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a technique for reducing the low temperature viscosity and / or pour point of an engine lubricating oil characterized by utilizing a limited combination of alkyl methacrylate copolymers. More specifically, the present invention relates to a technique for lowering the low-temperature viscosity and / or pour point of an engine lubricating oil using a high viscosity index base oil containing isomerized paraffin.

[0002]

2. Description of the Related Art Lubricating oils increase in viscosity as the temperature decreases, and at temperatures lower than the crystallization point of the wax contained in the lubricating oil, gelation occurs and finally complete solidification to improve fluidity. It is generally known to lose.

[0003] The solidification of lubricating oil at low temperature is due to the fact that wax contained in lubricating oil, which is paraffin, crystallizes when the lubricating oil is cooled, and the wax forms a network structure by further cooling. It is considered.
In order to improve the flowability of lubricating oil, a method is generally adopted in which the dewaxing step is performed at a somewhat low temperature to remove wax components that cause solidification to a certain extent and further add a pour point depressant. It is a target. It is said that the function of the pour point depressant is not to solubilize the wax in the lubricating oil, but to prevent the wax from forming a network structure. Generally, adding 0.2 mass% of a pour point depressant to a lubricating oil increases the pour point by -3.
Can drop to 5 ° C.

[0004] Further, due to recent social demands for fuel economy, it has been strongly desired that lubricating oils have low viscosity at low temperature. As one means for solving this problem, a high viscosity index base oil containing isomerized paraffin, or a combination thereof with an ordinary solvent refined base oil or a synthetic lubricating oil is being used. Attempts have been made to lower the pour point or lower the low temperature viscosity by using a pour point depressant. However, since there is a difference in molecular structure between the high viscosity index base oil and the solvent refined base oil, all of the pour point depressants which are used in ordinary solvent refined base oils and are effective are high viscosity index base oils. It is known that the additive is not always effective for lubricating oils, and there is a need for an additive for lubricating oil that exerts an effect on a high viscosity index base oil. In addition, there has been a growing demand for versatile lubricating oil additives that exhibit low temperature viscosity lowering ability and / or pour point lowering ability for both solvent refined base oils and high viscosity index base oils.

As a method of lowering the pour point of lubricating oil by using a polymer additive, the following is a known technique. U.S. Pat. No. 2,655,479 describes the use of polyalkyl (meth) acrylates having a limited average alkyl carbon number in pour point depressants and viscosity index improvers for lubricating oils. JP-A-49-99504 describes that a synergistic effect of a pour point depressant and the compound can be obtained by using a specific ethylene-propylene copolymer as a viscosity index improver. Tokushou 49-9
9505 discloses a copolymer of C4 to C12 n-methacrylate, a C4 to C12 n-methacrylate as a pour point depressant effective when a specific ethylene-propylene copolymer is used as a viscosity index improver. Copolymers of methacrylate and dialkylaminoalkyl esters of methacrylic acid and copolymers of C4 to C12 n-methacrylate and acryl-N- (alkanone) -amide are mentioned. JP-A-52-93404 discloses that a pour point depressant for a lubricating oil has an alkyl group having 8 carbon atoms.
To methacrylic acid copolymers, or vinyl pyridine and three-dimensional polymers. JP 54
No. 70305 describes, as a pour point depressant for lubricating oil, a copolymer of an alkyl (meth) acrylate having an alkyl group having 12 to 15 carbon atoms and an alkyl (meth) acrylate having an alkyl group having 16 carbon atoms. Have been. JP-A-61-241397 discloses lubricating oils such as vinyl acetate copolymers, polyalkyl acrylates, polyalkyl methacrylates or esterified olefin / maleic anhydride copolymers derived from linear alcohols having 4 to 20 carbon atoms. When used in combination with a pour point depressant for use as a compound that can be expected to have a synergistic effect of pour point depressing performance, a saturated alkyl group having 16 to 30 carbon atoms and a polyoxyalkylene glycol having a molecular weight of 100 to 5000 (carbon number of Use of esters and ethers with 1 to 4) is described. JP-A-63-502111 describes a polycondensate of a methylene-substituted aromatic compound as a novel pour point effect composition of a hydrocarbon oil. US Patent 4,867,
894 describes pour point depressants for mineral oils of 10 to 3
0 mol% methyl methacrylate and 10 to 70 mol%
Is a copolymer of a linear alkyl methacrylate having 16 to 30 carbon atoms and a linear alkyl methacrylate having 10 to 80 mol% of 4 to 15 carbon atoms or a branched alkyl methacrylate having 4 to 30 carbon atoms. . JP-A-4-2
No. 11498 discloses a specific alkyl methacrylate and an N, N-dialkylaminoalkyl methacrylate as an additive which functions as a viscosity index improver and a detergent dispersant for a hydrocarbon lubricating oil, and optionally also functions as a pour point effect agent. Copolymers with amides are described. JP-A-5-8
No. 6114 is an additive having a combined function of lowering pour point, dispersibility, and improving viscosity index for lubricating oils. Specific conjugated diolefin, methacrylate having alkyl group of 8 or less and carbon number of alkyl group are The use of copolymers of 12 to 20 methacrylates is described. JP-A-6-2
99184 describes olefin copolymers having specific alkyl side chains as pour point depressants for lubricating oils. JP-A-7-48421 discloses a pour point depressant for lubricating oils in which an alkyl (meth) acrylate having an alkyl group content of 8 to 15 and a content of 3 to 40 mol% is used. An alkyl group having an alkyl (meth) acrylate having 16 to 24 carbon atoms and an alkyl group having a content of 30 to 65 mol% having 1 carbon atom
To 4 alkyl (meth) acrylates are described. JP-A-7-286189 discloses alkyl (meth) acrylate and N-vinylpyrrolidone / N, N-dialkylaminoalkyl (meth) acrylate / vinylpyridine as viscosity index improvers having both excellent low-temperature fluidity and oxidation resistance.・ Morphoethyl (meta)
Copolymers with one or more compounds selected from acrylate vinylimidazole are described. JP 1
No. 0-176178 discloses a method of improving low-temperature fluidity, heat resistance, and pitting resistance by using a thermal copolymer of cyclopentadiene and an α-olefin or a monovinyl aromatic hydrocarbon or its hydrogen in mineral oil or synthetic oil. Is described. JP-A-11-80331
Describes a polyester obtained by condensing a saturated aliphatic dicarboxylic acid or a derivative thereof with an aliphatic diol having a specific carbon number as a lubricating base oil having excellent low-temperature fluidity and a high viscosity index. .

As described above, copolymers of alkyl methacrylate or copolymers of alkyl methacrylate and other polymerizable monomers as pour point depressants have been known in many cases, such as solvent refined base oils and the like. Is widely used in existing base oils. However, few of the known prior patents describe technologies effective for lubricating oils using a high viscosity index base oil as in the present invention. It is only natural that petroleum refining manufacturers and others have begun to pay attention to the use of this high viscosity index base oil since it is relatively recent.

The use of polyalkyl (meth) acrylates as pour point depressants for lubricating oils using high viscosity index base oils is described in Japanese Patent Application Laid-Open No. 54-70305, the contents of which are described in more detail below. I do. In this technique, it is an essential condition that the number of alkyl carbon atoms of the main component of the polymerized alkyl methacrylate is limited to 12 to 15, and the content of methacrylate having an alkyl carbon number of 16 or more is 10 to 90% by weight. However, even with this technique, low temperature viscosity and / or lubricating oils using high viscosity base oils
Alternatively, the effect of lowering the pour point is not sufficient.

[0008]

The problem to be solved by the present invention is that the additives of the prior art are less effective at lowering the low temperature viscosity and / or lowering the pour point than the high viscosity index base oil. In addition, it has the effect of lowering the low temperature viscosity and / or the effect of lowering the pour point for both the high viscosity index base oil and the solvent refined base oil.
The point is that there is no lubricating oil additive excellent in versatility.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a methacrylate-based polymer having a specific alkyl carbon number has a high viscosity index base oil which has been used due to recent social demands. The fact that it has the effect of easily lowering the low-temperature viscosity and / or lowering the pour point with a small amount of addition, and has the same effect on the normally used solvent refined base oil, The present invention has been reached.

That is, according to the present invention, an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms or a mixture thereof is added to an alkyl methacrylate represented by the structural formula (2) or a mixture thereof as a constituent unit.
s% to 15 mass%, and is an additive for lowering the low-temperature viscosity of lubricating oil and / or lowering the pour point obtained by copolymerizing this mixture. Equation 2 Where R is a hydrocarbon group having 5 to 22 carbon atoms

In the present invention, the methacrylate represented by the structural formula 2 is a methacrylate having a straight-chain and / or branched alkyl group having 5 to 22 carbon atoms in the alkyl group. Examples of these include pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate,
Decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, tetradecyl methacrylate,
Examples include pentadecyl methacrylate, hexadecyl methacrylate, heptadecyl methacrylate, octadecyl methacrylate, nonadecyl methacrylate, eicosyl methacrylate, heneicosyl methacrylate, docosyl methacrylate, and the like, and mixtures thereof.

Examples of the alkyl methacrylate having 1 to 4 carbon atoms in the alkyl group include methyl methacrylate,
Ethyl methacrylate, isopropyl methacrylate,
Examples include n-butyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, and the like, and mixtures thereof. However, when copolymerization is carried out using methyl methacrylate or ethyl methacrylate, the viscosity of the obtained additive increases, and a handling problem may occur. Also, when a methacrylate having a branched alkyl group is used, a sufficient pour point reduction and / or a sufficient low-temperature viscosity reduction performance may not be obtained depending on the paraffin composition of the lubricating oil. Therefore, more preferably, use of n-butyl methacrylate is desirable. Furthermore, the content of these methacrylates is desirably 5 mass% to 15 mass%, and if the content is lower than this range, the resulting additive has insufficient performance of lowering the low-temperature viscosity and / or the performance of lowering the pour point. If the content is higher than this range, the solubility in lubricating oil may be adversely affected, and the obtained additive may have a performance of lowering the low-temperature viscosity and / or a pour point. Performance may be insufficient.

These methacrylates are easily produced by an esterification reaction between methacrylic acid and a natural or synthetic alcohol or a transesterification reaction between a methacrylic acid ester having a small alkyl carbon number such as methyl methacrylate and a natural or synthetic alcohol. be able to. If a natural alcohol is used, the alkyl group becomes straight-chain, and the number of carbon atoms becomes even only. If a synthetic alcohol is used, the alkyl group will be a mixture of straight and branched chains, and the number of carbon atoms will be a mixture of odd and even numbers.

The additives of the present invention have a preferred molecular weight. Usually, the weight average molecular weight (Mw) needs to be in the range of 50,000 to 300,000. If the Mw is lower than this range, the resulting additive may have insufficient performance of lowering the low-temperature viscosity and / or the performance of lowering the pour point. If the Mw is higher than this range, the solubility in oil is poor. In addition, the viscosity increases, which may cause handling problems. This molecular weight was determined by GPC (Gel Permeati) using polystyrene as a calibration curve.
onchromatography).

The lubricating oil additive of the present invention is a copolymer of a mixture of methacrylates having a specific alkyl group.
If necessary, a polymer containing at least one monomer having at least one atom selected from a nitrogen atom, an oxygen atom, a sulfur atom, and a phosphorus atom may be used. In this case, in addition to the inherent properties of the additive, properties such as clean dispersibility, antioxidant properties, and lubricity can be added, which is more preferable.

The additive of the present invention can be easily obtained by a usual method, and the production method is not limited. For example, it is obtained by radical polymerization using a diluent, a selected type and amount of alkyl methacrylate, a polymerization initiator, and a chain transfer agent. It can also be obtained by thermally polymerizing a diluent, a selected type and amount of alkyl methacrylate.

The use of a diluent is optional, but the use of a diluent makes it easier to control the molecular weight of the polymer. Further, since the polymer has viscosity, handling problems can often be solved. The diluent used may be any inert hydrocarbon, but must be compatible with the copolymer and the lubricating oil. The standard amount of the diluent is 30 mass% to 400 ma based on the alkyl methacrylate to be polymerized.
It will be about ss%.

Suitable polymerization initiators include those which decompose on heating to form free radicals, for example, peroxide compounds such as benzoyl peroxide, t-butyl peroctoate, cumene hydroperoxide and the like. Examples include azo compounds such as azobisisobutyronitrile and 2,2′-azobis (2-methylbutanenitrile). The standard amount of the polymerization initiator will be about 0.2 mass% to 1 mass% based on the alkyl methacrylate to be polymerized.

Suitable chain transfer agents include those commonly used in the art, for example, α-styrene dimer, dodecyl mercaptan, ethyl mercaptan and the like. The use of a chain transfer agent is optional, but the use of a chain transfer agent makes it easier to control the molecular weight of the polymer.

The solvent-refined base oil of the present invention refers to a vacuum distilled oil or a depanned oil of propane after removing aromatic components by extraction with furfural or the like and then dewaxing with a solvent such as a mixed solvent of toluene / methyl ethyl ketone or propane. A thing.

The isomerized paraffin-containing high viscosity index base oil of the present invention is greatly different from those produced by ordinary solvent refining and the like. This high viscosity index base oil is n-
Paraffin is obtained by hydrocracking using a catalyst and containing a component isomerized into i-paraffin. A noble metal catalyst is usually used as the hydrocracking catalyst at this time. Such an isomerized paraffin-containing base oil has a larger composition than a normal solvent-refined base oil, and thus has a higher viscosity index.

The additive for lubricating oils of the present invention can be used for isomerized paraffin-containing high viscosity index base oil alone and solvent-refined base oil alone. The present invention also includes a case where the composition is used for a mixture of a base oil and a mixture of the above oil and a synthetic lubricating oil. Synthetic lubricating oils include ester-based oils (such as esters of alcohols and fatty acids such as trimethylolpropane and hexamethylenediol, and esters of adipic acid and fatty acid fatty acids) and polyolefin-based oils (such as decene oligomers). PAO type).

In addition to the additives of the present invention, lubricating oils may contain other additives, such as pour point depressants, such as alkyl (meth) acrylate copolymers, which are outside the scope of the present invention, which are known in the art, dithiophosphates Antioxidants, such as overbased metal sulfonates, detergent / dispersants, such as overbased metal sulfonates, defoamers such as silicone polymers, and alkyl (meth) acrylate copolymers, olefin copolymers, hydrogenated styrene-butadiene copolymers and the like. It may contain a suitable viscosity index improver.

The method of testing the performance of additives includes pour point and low temperature viscosity. A pour point test method for petroleum products is described in JIS K 2269, and this method is widely used. Measurement of low-temperature viscosity for engine oil is generally performed by CCS (Cold Cracking).
Simulator) viscosity and MRV (MiniRo)
The test method is described in the JPI method.

[0025]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 100 g of mineral oil was placed in a reaction tank equipped with a stirrer, a nitrogen-in-liquid introduction tube, a thermometer, and a condenser, and the air in the reaction tank was replaced with nitrogen. While flowing a small amount of nitrogen from a submerged nitrogen inlet tube, the monomer (dodecyl methacrylate 5 g, tridecyl methacrylate 10 g, tetradecyl methacrylate 20 g, pentadecyl methacrylate 15 g, hexadecyl methacrylate 20 g, heptadecyl methacrylate 10 g,
A mixture of 10 g of octadecyl methacrylate, 10 g of butyl methacrylate), 0.3 g of azobisisobutyronitrile as a polymerization initiator, and 0.5 g of lauryl mercaptan as a chain transfer agent was added dropwise over 3 hours.
Aged at 0 ° C. for 3 hours to obtain a polymer.

Example 2 As monomers, 20 g of tetradecyl methacrylate and 1 of hexadecyl methacrylate were used.
Polymerization was performed in the same manner as in Example 1 except that 5 g, 50 g of octadecyl methacrylate, and 15 g of butyl methacrylate were used to obtain a polymer.

Example 3 As monomers, 5 g of dodecyl methacrylate, 10 g of tridecyl methacrylate, 20 g of tetradecyl methacrylate, 20 g of pentadecyl methacrylate, 20 g of hexadecyl methacrylate,
Polymerization was performed in the same manner as in Example 1 except that 10 g of heptadecyl methacrylate, 10 g of octadecyl methacrylate, and 5 g of butyl methacrylate were used to obtain a polymer.

Example 4 As monomers, 70 g of tetradecyl methacrylate and 1 of hexadecyl methacrylate were used.
Polymerization was performed in the same manner as in Example 1 except that 0 g, 15 g of octadecyl methacrylate, and 5 g of butyl methacrylate were used to obtain a polymer.

Example 5 As monomers, 70 g of tetradecyl methacrylate and 1 of hexadecyl methacrylate were used.
Polymerization was performed in the same manner as in Example 1 except that 0 g, 10 g of octadecyl methacrylate, and 10 g of butyl methacrylate were used to obtain a polymer.

Example 6 As monomers, 65 g of tetradecyl methacrylate and 1 of hexadecyl methacrylate 1
Polymerization was performed in the same manner as in Example 1 except that 0 g, 10 g of octadecyl methacrylate, and 15 g of butyl methacrylate were used to obtain a polymer.

Example 7 As monomers, 5 g of dodecyl methacrylate, 10 g of tridecyl methacrylate, 20 g of tetradecyl methacrylate, 15 g of pentadecyl methacrylate, 20 g of hexadecyl methacrylate,
Polymerization was performed in the same manner as in Example 1 except that 10 g of heptadecyl methacrylate, 10 g of octadecyl methacrylate, and 10 g of methyl methacrylate were used to obtain a polymer.

Example 8 As monomers, 20 g of tetradecyl methacrylate and 1 of hexadecyl methacrylate were used.
Polymerization was performed in the same manner as in Example 1 except that 5 g, 50 g of octadecyl methacrylate, and 15 g of methyl methacrylate were used to obtain a polymer.

Example 9 As monomers, 5 g of dodecyl methacrylate, 10 g of tridecyl methacrylate, 20 g of tetradecyl methacrylate, 20 g of pentadecyl methacrylate, 20 g of hexadecyl methacrylate,
Polymerization was performed in the same manner as in Example 1 except that 10 g of heptadecyl methacrylate, 10 g of octadecyl methacrylate, and 5 g of methyl methacrylate were used to obtain a polymer.

Example 10 Polymerization was carried out in the same manner as in Example 1, except that 70 g of tetradecyl methacrylate, 10 g of hexadecyl methacrylate, 15 g of octadecyl methacrylate and 5 g of methyl methacrylate were used as monomers. Obtained.

Example 11 Polymerization was carried out in the same manner as in Example 1, except that 70 g of tetradecyl methacrylate, 10 g of hexadecyl methacrylate, 10 g of octadecyl methacrylate and 10 g of methyl methacrylate were used as monomers. I got

Example 12 Polymerization was carried out in the same manner as in Example 1 except that 65 g of tetradecyl methacrylate, 10 g of hexadecyl methacrylate, 10 g of octadecyl methacrylate and 15 g of methyl methacrylate were used as monomers. Obtained.

Comparative Example 1 As monomers, 6 g of dodecyl methacrylate, 11 g of tridecyl methacrylate, 22 g of tetradecyl methacrylate, 17 g of pentadecyl methacrylate, 22 g of hexadecyl methacrylate,
Polymerization was carried out in the same manner as in Example 1 except that 11 g of heptadecyl methacrylate and 11 g of octadecyl methacrylate were used to obtain a polymer.

Comparative Example 2 As monomers, tetradecyl methacrylate 24 g, hexadecyl methacrylate 1
Polymerization was carried out in the same manner as in Example 1 except that 8 g and 58 g of octadecyl methacrylate were used to obtain a polymer.

Comparative Example 3 As monomers, 5 g of dodecyl methacrylate, 10 g of tridecyl methacrylate, 21 g of tetradecyl methacrylate, 21 g of pentadecyl methacrylate, 21 g of hexadecyl methacrylate,
Polymerization was carried out in the same manner as in Example 1 except that 11 g of heptadecyl methacrylate and 11 g of octadecyl methacrylate were used to obtain a polymer.

Comparative Example 4 As monomers, 74 g of tetradecyl methacrylate and 1 of hexadecyl methacrylate 1
Polymerization was carried out in the same manner as in Example 1 except that 0 g and 16 g of octadecyl methacrylate were used to obtain a polymer.

Comparative Example 5 As monomers, 5 g of dodecyl methacrylate, 10 g of tridecyl methacrylate, 20 g of tetradecyl methacrylate, 20 g of pentadecyl methacrylate, 20 g of hexadecyl methacrylate,
Polymerization was performed in the same manner as in Example 1 except that 11 g of heptadecyl methacrylate, 11 g of octadecyl methacrylate, and 3 g of butyl methacrylate were used to obtain a polymer.

Comparative Example 6 5 g of dodecyl methacrylate, 7 g of tridecyl methacrylate, 19 g of tetradecyl methacrylate, 18 g of pentadecyl methacrylate, 19 g of hexadecyl methacrylate, 7 g of heptadecyl methacrylate, 7 g of octadecyl methacrylate and 18 g of butyl methacrylate were used as monomers. Polymerization was carried out in the same manner as in Example 1 except that it was used to obtain a polymer.

Comparative Example 7 As monomers, 5 g of dodecyl methacrylate, 7 g of tridecyl methacrylate, 18 g of tetradecyl methacrylate, 17 g of pentadecyl methacrylate, 17 g of hexadecyl methacrylate, 7 g of heptadecyl methacrylate, 7 g of octadecyl methacrylate and 22 g of butyl methacrylate were used. Polymerization was carried out in the same manner as in Example 1 except that it was used to obtain a polymer.

(Use Examples 1 to 12 and Comparative Use Examples 1 to 7)
The polymers obtained in Examples 1 to 12 and the polymers obtained in Comparative Examples 1 to 7 were mixed with a high viscosity index base oil A (5W-30 viscosity grade) and a solvent refined base oil B (5W-30 viscosity grade). )
And 0.2 mass% and 0.3 mass%, respectively, to the MRV (mini rotaryviscomet).
er) The test was performed and the results in Table 1 were obtained. Example 1
The polymer obtained in Comparative Examples 1 to 7 and the polymer obtained in Comparative Examples 1 to 7 were mixed with the same high viscosity index base oil A and solvent refined base oil B as described above.
And 0.2 mass% and 0.3 mass%, respectively, were added, and a pour point measurement test was performed. The results in Table 2 were obtained.

[0046]

From these results, it is apparent that the additive of the present invention has an effect of lowering the low-temperature viscosity and the pour point of the lubricating oil using a high viscosity index base oil at a low addition amount. . Similar effects are obtained for lubricating oils that use solvent refined base oils, and are more versatile than lubricating oils that use high viscosity index base oils and lubricating oils that use solvent refined base oils. It is clear that this is an additive.

[0047]

[Table 1]

[0048]

[Table 2]

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C10N 30:02 C10N 30:02 40:25 40:25 70:00 70:00

Claims (3)

[Claims] An methacrylate represented by the formula 1 or a mixture thereof is copolymerized with an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms or a mixture thereof in a range of 5 mass% to 15 mass%. A lubricating oil additive for high viscosity index base oils containing isomerized paraffin for the purpose of lowering low temperature viscosity and / or pour point. Equation 1 Where R is a hydrocarbon group having 5 to 22 carbon atoms 2. The method according to claim 1, wherein the lubricating oil additive according to
A lubricating oil composition using an isomerized paraffin-containing high viscosity index base oil containing 5 mass% to 2.0 mass%. 3. A methacrylate represented by the formula (1) or a mixture thereof is added with an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms or a mixture thereof in an amount of 5 to 15% by weight.
For lubricating oils that can be used as both a high viscosity index base oil containing isomerized paraffin and a solvent refined base oil for the purpose of lowering low temperature viscosity and / or pour point, characterized by copolymerization in the range of weight%. Additive.