JP2010053252A - Lubricant additive composition, lubricant composition and methods for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant additive composition which is excellent in viscosity index improving effect and is excellent in flow property. <P>SOLUTION: The lubricant additive composition contains (A) a poly(meth)acrylate compound, (B) a diluent and (C) an ester compound having a carbon/oxygen atom ratio of ≤10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lubricating oil additive composition, a lubricating oil composition, and a method for producing the same.

  In various mechanical devices such as an internal combustion engine and a transmission, a lubricating oil composition is used for smooth driving and operation. In particular, a lubricating oil (engine oil) for an internal combustion engine needs to have a performance that can be used under severe conditions in accordance with higher performance and higher output of the internal combustion engine.

  In order to satisfy such required performance, various additives such as an antiwear agent, a metallic detergent, an ashless dispersant, and an antioxidant are blended in the engine oil. (See, for example, Patent Documents 1 to 3 below.)

  By the way, recently, with the environmental problem attracting attention, improvement in fuel efficiency of engine oil is strongly demanded. In order to meet such a demand, use of a high viscosity index base oil or various friction modifiers for engine oil has been studied (for example, see Patent Document 4 below).

In addition, in order to improve fuel economy and low friction properties of lubricating oil compositions such as engine oil, the viscosity of the lubricating base oil is reduced and the amount of the viscosity index improver is increased. ing. For this reason, the usage amount of the viscosity index improver is increasing, and the viscosity index improver plays an increasingly important role as an additive of the lubricating oil composition.
JP 2001-279287 A JP 2002-129182 A JP 08-302378 A Japanese Patent Laid-Open No. 06-306384

  A viscosity index improver, which is a kind of lubricating oil additive composition, has a significantly higher viscosity than other lubricating oil additives. A lubricating oil composition obtained by blending a lubricating oil additive and a lubricating base oil usually needs to be adjusted in viscosity at the production stage. For this reason, viscosity index improvers are generally handled individually without being packaged with other lubricant additives.

  As an active ingredient of a viscosity index improver (a component having an effect of improving the viscosity index), poly (meth) acrylate compounds having a weight average molecular weight (Mw) of 10,000 to 1,000,000 are used, and the weight average molecular weight is used. The larger the value (Mw: 350,000 to 1,000,000), the higher the viscosity tends to be.

  In order to give the viscosity index improver a certain fluidity and improve handling, it is generally handled in a state diluted with a diluent, but the content of the diluent is increased in order to ensure sufficient fluidity. If it is too high, the content of the active ingredient of the viscosity index improver is lowered, and the distribution efficiency is deteriorated. In addition, in order to obtain a predetermined effect of improving the viscosity index, the amount added to the lubricating base oil increases as a result, and the cost increases due to the deterioration of physical distribution efficiency and the amount added to the lubricating oil. In addition, when a low-viscosity diluent is used, the effect on the performance of the lubricating oil composition (evaporation loss and lubrication characteristics due to the low-viscosity diluent, sulfur content, nitrogen content, aromatics contained in the diluent) There is a concern about the influence of heat and oxidation stability due to the minute etc.).

  On the other hand, another means for improving the fluidity of the lubricating oil additive is to moderately warm the viscosity index improver and the lubricating oil composition in the physical distribution stage and the lubricating oil composition manufacturing stage. However, such heating tends to cause deterioration of the viscosity index improver and deterioration of the storage stability of the lubricating oil composition.

  This invention is made | formed in view of the said situation, and it aims at providing the lubricating oil additive composition which had the outstanding viscosity index improvement effect and the outstanding fluidity | liquidity. It is another object of the present invention to provide a method for easily producing such a lubricating oil additive composition. Furthermore, by including such a lubricating oil additive composition, a lubricating oil composition having a sufficiently high viscosity index and sufficiently reduced volatility, and such a lubricating oil composition are easily produced. It aims to provide a way to do.

  In order to achieve the above object, the present invention provides (A) a poly (meth) acrylate-based compound, (B) a diluent, and (C) a carbon / oxygen atom number ratio (hereinafter referred to as “C / O ratio” in some cases). Also provided is a lubricating oil additive composition containing 10 or less ester compounds.

  The lubricating oil additive composition of the present invention has both excellent fluidity and an excellent viscosity index improvement effect. That is, since the lubricating oil additive composition of the present invention contains (B) a diluent and (C) an ester compound having a C / O ratio of 10 or less, the content of (B) the diluent is reduced. Even so, excellent fluidity can be secured. Further, since the content of the active ingredient (A) poly (meth) acrylate compound can be increased while maintaining fluidity, an excellent viscosity index improvement effect is obtained when blended with a lubricating base oil. be able to. In addition, since the content of the diluent (B) can be reduced, the transportation cost can be reduced by improving the distribution efficiency and the environmental load during transportation can be reduced, and the production of a lubricating oil additive composition and a lubricating oil composition can be achieved. The cost can be reduced and the volatility of the lubricating oil composition can be improved.

  In the lubricating oil additive composition of the present invention, the ester compound (C) is (C1) an ester compound of a polyhydric alcohol having a C / O ratio of 10 or less, and (C2) a polyvalent compound having a C / O ratio of 10 or less. It is preferably at least one selected from the group consisting of carboxylic acid ester compounds and (C3) monoester compounds having a C / O ratio of 10 or less. Thereby, even if the content of the diluent (B) is reduced, a lubricating oil additive composition having more excellent fluidity can be obtained. Moreover, since the content of the (A) poly (meth) acrylate compound, which is an active ingredient, can be further increased, a more excellent viscosity index improvement effect can be obtained when blended with a lubricating base oil.

  In the lubricating oil additive composition of the present invention, the ester compound (C) is preferably an ester compound of a polyhydric alcohol and a carboxylic acid having 17 or less carbon atoms. By using the ester compound, a lubricating oil additive composition having even better fluidity can be obtained even when the content of the diluent (B) is reduced. Moreover, since the content of the (A) poly (meth) acrylate compound, which is an active ingredient, can be further increased, a more excellent viscosity index improvement effect can be obtained when blended with a lubricating base oil.

  The present invention also provides a lubricating oil additive composition comprising a step of mixing (A) a poly (meth) acrylate-based compound, (B) a diluent, and (C) an ester compound having a C / O ratio of 10 or less. A manufacturing method is provided. By this production method, it is possible to effectively obtain a lubricating oil additive composition having excellent fluidity and an excellent viscosity index improving effect.

  The present invention also provides a lubricating oil composition comprising a lubricating base oil and the lubricating oil additive composition of the present invention. Such lubricating oil compositions have a sufficiently high viscosity index and a sufficiently reduced volatility.

  The present invention also provides a method for producing a lubricating oil composition comprising a step of mixing the lubricating base oil and the lubricating oil additive composition of the present invention. Since the lubricating oil additive composition has excellent fluidity, the lubricating oil composition is excellent in handling properties, and the lubricating oil composition can be easily produced by this production method. The resulting lubricating oil composition has a sufficiently high viscosity index and a sufficiently reduced volatility.

  ADVANTAGE OF THE INVENTION According to this invention, the lubricating oil additive composition which has the outstanding viscosity index improvement effect and the outstanding fluidity | liquidity can be provided. Moreover, the method of manufacturing such a lubricating oil additive composition easily can be provided. Furthermore, by including such a lubricating oil additive composition, a lubricating oil composition having a sufficiently high viscosity index and sufficiently reduced volatility, and such a lubricating oil composition are easily produced. A method can be provided.

  Further, according to the present invention, the transportation cost by improving the logistics efficiency of the lubricating oil additive composition, the reduction of environmental burden during transportation, and the manufacturing cost of the lubricating oil additive composition and the lubricating oil composition are sufficiently reduced. be able to.

  Hereinafter, preferred embodiments of the lubricating oil additive composition and the lubricating oil composition of the present invention will be described.

  The lubricating oil additive composition of this embodiment contains (A) a poly (meth) acrylate-based compound (hereinafter sometimes referred to as “component (A)”). This poly (meth) acrylate compound has a function as a viscosity index improver and / or a pour point depressant. In addition, the “poly (meth) acrylate compound” in this specification is a general term for a polyacrylate compound and a polymethacrylate compound.

  (A) The poly (meth) acrylate compound is a polymer of a polymerizable monomer containing a (meth) acrylate monomer (hereinafter referred to as “monomer M-1”) represented by the following general formula (1). Is preferred. (A) The poly (meth) acrylate compound may be a composite polymer of the monomer M-1 and an olefin compound (ethylene, α-olefin, styrene, isobutylene, diene, maleic acid, etc.).

［一般式（１）中、Ｒ^１は水素又はメチル基を示し、Ｒ^２は炭素数１〜２００の直鎖状又は分枝状の炭化水素基を示し、それらの誘導体であっても良い。］

[In General Formula (1), R ¹ represents hydrogen or a methyl group, R ² represents a linear or branched hydrocarbon group having 1 to 200 carbon atoms, and may be a derivative thereof. ]

Examples of the linear or branched hydrocarbon group having 1 to 200 carbon atoms represented by R ² in the general formula (1) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. Alkyl groups such as heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tetradecyl group, hexadecyl group and octadecyl group (these alkyl groups may be linear or branched); butenyl group, Alkenyl groups such as pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tetradecenyl group, hexadecenyl group and octadecenyl group (these alkenyl groups may be linear or branched) And the position of the double bond is also arbitrary).

  The (A) poly (meth) acrylate-based compound may be a so-called non-dispersed poly (meth) acrylate obtained by one kind of homopolymerization or two or more kinds of copolymerization of the monomer M-1.

  (A) The poly (meth) acrylate compound is represented by the monomer M-1, the (meth) acrylate monomer represented by the general formula (2) (hereinafter referred to as “monomer M-2”), and the general formula (3). It may be a so-called dispersed poly (meth) acrylate obtained by copolymerization with one or more monomers selected from the group consisting of the represented monomers (hereinafter referred to as “monomer M-3”).

［一般式（２）中、Ｒ^３は水素原子又はメチル基を示し、Ｒ^４は炭素数１〜１８のアルキレン基を示し、Ｅ^１は窒素原子を１〜２個、酸素原子を０〜２個含有するアミン残基又は複素環残基を示し、ａは０又は１を示す。］

[In General Formula (2), R ³ represents a hydrogen atom or a methyl group, R ⁴ represents an alkylene group having 1 to 18 carbon atoms, E ¹ represents ¹ to 2 nitrogen atoms, and 0 to 2 oxygen atoms. Each represents an amine residue or a heterocyclic residue, and a represents 0 or 1. ]

Specific examples of the alkylene group having 1 to 18 carbon atoms represented by R ⁴ in the general formula (2) include an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, and an octylene group. , Nonylene group, decylene group, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, and octadecylene group (these alkylene groups may be linear or branched). it can.

Specific examples of the amine residue or heterocyclic residue represented by E ¹ in the general formula (2) include a dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, an anilino group, and a toluidino group. , Xylidino group, acetylamino group, benzoylamino group, morpholino group, pyrrolyl group, pyrrolino group, pyridyl group, methylpyridyl group, pyrrolidinyl group, piperidinyl group, quinonyl group, pyrrolidonyl group, pyrrolidono group, imidazolino group, pyrazino group, etc. Can be illustrated.

［一般式（３）中、Ｒ^５は水素原子又はメチル基を示し、Ｅ^２は窒素原子を１〜２個、酸素原子を０〜２個含有するアミン残基又は複素環残基を示す。］

[In General Formula (3), R ⁵ represents a hydrogen atom or a methyl group, and E ² represents an amine residue or a heterocyclic residue containing 1 to 2 nitrogen atoms and 0 to 2 oxygen atoms. ]

The amine residue or heterocyclic residue represented by E ² in the general formula (3), specifically, dimethylamino, diethylamino, dipropylamino, dibutylamino, anilino, toluidino group , Xylidino group, acetylamino group, benzoylamino group, morpholino group, pyrrolyl group, pyrrolino group, pyridyl group, methylpyridyl group, pyrrolidinyl group, piperidinyl group, quinonyl group, pyrrolidonyl group, pyrrolidono group, imidazolino group, pyrazino group, etc. Can be illustrated.

  The amine residue in the general formulas (2) and (3) refers to a monovalent group obtained by removing the hydrogen of the amino group from the amine, and the heterocyclic residue constitutes a heterocyclic ring from a molecule having a heterocyclic structure. A monovalent group excluding hydrogen bonded to carbon.

  Preferred specific examples of the monomer M-2 and the monomer M-3 include dimethylaminomethyl methacrylate, diethylaminomethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-methyl-5-vinylpyridine, morpholinomethyl methacrylate, morpholinoethyl methacrylate. , N-vinylpyrrolidone, and mixtures thereof.

  (A) The poly (meth) acrylate compound is composed of a monomer represented by the general formula (1) and one or more monomers selected from the following general formulas (4) and (5) (hereinafter referred to as “monomer M”). -4 "and" monomer M-5 ") may be a so-called composite polymer. Among the composite polymers, a (meth) acrylate-olefin copolymer is preferable.

［一般式（４）中、Ｒ^６は水素又はメチル基を示し、Ｒ^７は炭素数１〜５００の炭化水素基を示す。］

[In General Formula (4), R ⁶ represents hydrogen or a methyl group, and R ⁷ represents a hydrocarbon group having 1 to 500 carbon atoms. ]

Specific examples of the hydrocarbon group having 1 to 500 carbon atoms represented by R ⁷ in the general formula (4) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a heptyl group. Alkyl groups such as octyl group, nonyl group, decyl group, undecyl group, dodecyl group (these alkyl groups may be linear or branched); butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, Nonenyl group, decenyl group, undecenyl group, dodecenyl group and the like alkenyl groups (these alkenyl groups may be linear or branched, and the position of the double bond is arbitrary); cyclopentyl group, cyclohexyl group, cycloheptyl group A cycloalkyl group having 5 to 7 carbon atoms such as methylcyclopentyl group, dimethylcyclopentyl group, methylethylcyclopentyl group, Alkyl having 6 to 11 carbon atoms such as diethylcyclopentyl group, methylcyclohexyl group, dimethylcyclohexyl group, methylethylcyclohexyl group, diethylcyclohexyl group, methylcycloheptyl group, dimethylcycloheptyl group, methylethylcycloheptyl group, diethylcycloheptyl group Cycloalkyl groups (the position of substitution of these alkyl groups with cycloalkyl groups is arbitrary); aryl groups such as phenyl groups and naphthyl groups; tolyl groups, xylyl groups, ethylphenyl groups, propylphenyl groups, butylphenyl groups, pentyl groups Each alkylaryl group having 7 to 12 carbon atoms such as phenyl group and hexylphenyl group (the alkyl group may be linear or branched, and the substitution position on the aryl group is arbitrary); benzyl group, phenyl Ethyl group, phenyl group Propyl group, a phenyl butyl group, a phenyl pentyl group, each phenyl alkyl group having 7 to 12 carbon atoms such as a phenyl hexyl group (the alkyl group may be branched straight-chain); can be exemplified, and the like.

［一般式（５）中、Ｒ^８及びＲ^９は、それぞれ独立に、水素原子、炭素数１〜１８のアルキルアルコールの残基（−ＯＲ^１０：Ｒ^１０は炭素数１〜１８のアルキル基）又は炭素数１〜１８のモノアルキルアミンの残基（−ＮＨＲ^１１：Ｒ^１１は炭素数１〜１８のアルキル基）を示す。］

[In General Formula (5), R ⁸ and R ⁹ are each independently a hydrogen atom or an alkyl alcohol residue having 1 to 18 carbon atoms (-OR ¹⁰ : R ¹⁰ is an alkyl group having 1 to 18 carbon atoms). or monoalkylamine residue having 1 to 18 carbon atoms ^{(-NHR 11: R} 11 is an alkyl group having 1 to 18 carbon atoms). ]

Examples of the residue of the alkyl alcohol represented by R ⁸ and R ⁹ in the general formula (5) include methanol, ethanol, linear or branched propanol, linear or branched butanol, linear or Branched pentanol, linear or branched hexanol, linear or branched heptanol, linear or branched octanol, linear or branched nonanol, linear or branched decanol , Linear or branched undecanol, linear or branched dodecanol, linear or branched tridecanol, linear or branched tetradecanol, linear or branched pentadecanol, Residues such as linear or branched hexadecanol, linear or branched heptadecanol, linear or branched octadecanol and the like can be mentioned. A residue here means the monovalent group remove | excluding the hydrogen of the hydroxyl group from the alkyl alcohol.

Examples of the residue of the monoalkylamine represented by R ⁸ and R ⁹ in the general formula (5) include amine residues having an alkyl group having 1 to 18 carbon atoms such as methylamine, ethylamine, and propylamine. It is done. A residue here means the monovalent group remove | excluding the hydrogen of the amino group from the amine.

  (A) The poly (meth) acrylate compound is one selected from the monomer M-1, one or more monomers selected from the monomer M-2 and the monomer M-3, the monomer M-4 and the monomer M-5. A so-called dispersion type composite polymer obtained by copolymerization with at least one kind of monomer may be used, and a dispersion type (meth) acrylate-olefin copolymer may be preferable.

  There is no particular limitation on the copolymerization molar ratio of the copolymer of monomer M-1 and monomers M-2 and M-3, but M-1: M-2 and M-3 are preferably 99: 1 to 1. 80:20, more preferably 98: 2-85: 15, still more preferably 95: 5-90: 10.

  There is no particular limitation on the copolymerization molar ratio of the copolymer of the monomer M-1 and the monomers M-2, M-3, M-4 and M-5 (M-2 to M-5). 1: M-2 to M-5 are preferably 99: 1 to 20:80, more preferably 95: 5 to 40:60, and still more preferably 90:10 to 50:50.

  (A) The manufacturing method of a poly (meth) acrylate type compound is arbitrary. For example, in the presence of a polymerization initiator such as benzoyl peroxide, a mixture of monomer M-1 and monomers M-2 to M-3 is used. It can be easily obtained by radical solution polymerization.

(A) a weight average molecular weight of the poly (meth) acrylate compound _{(M W)} is preferably 5,000 or more, more preferably 50,000 or more, further to be 100,000 or more It is preferably 200,000 or more, and most preferably 300,000 or more.

The weight average molecular weight (M _w ) is preferably 1,000,000 or less, more preferably 700,000 or less, further preferably 600,000 or less, and 500,000 or less. It is particularly preferred.

  When the weight average molecular weight is less than 5,000, the viscosity index improving effect tends to be small when the lubricating oil additive composition is dissolved in the lubricating base oil. For this reason, there exists a possibility that a fuel-saving property, a low-temperature viscosity characteristic may fall, and cost may increase. On the other hand, when the weight average molecular weight exceeds 1,000,000, the shear stability of the lubricating oil additive composition, the solubility of the lubricating oil additive composition in the lubricating base oil, and the lubricating oil additive Sufficient storage stability of the composition and lubricating oil composition tends to be impaired.

  (A) The PSSI (Permanent Cystability Index) of the poly (meth) acrylate compound is preferably 50 or less, more preferably 5 to 40, still more preferably 10 to 35, particularly preferably 15 to 30, and most preferably 20. ~ 25. When PSSI exceeds 40, there exists a tendency for shear stability to be impaired. On the other hand, when PSSI is less than 5, when the lubricating oil additive composition is dissolved in the lubricating base oil, an excellent viscosity index improving effect tends to be difficult to obtain. For this reason, there exists a possibility that sufficient fuel-saving property and low-temperature viscosity characteristic of the obtained lubricating oil composition may be impaired, and cost may increase.

  In addition, “PSSI” in this specification conforms to ASTM D 6022-01 (Standard Practical for Cal- mation of Permanent Shear Stability Index), and ASTM D 6278-02 (Test Method for Strain for Shar. Means the permanent shear stability index of the polymer, calculated based on the data measured by Diesel Injector Apparatus.

  The content of the (A) poly (meth) acrylate compound in the lubricating oil additive composition of the present embodiment is preferably 1 to 70% by mass, more preferably 5 to 50, based on the total amount of the lubricating oil additive composition. It is 10 mass%, More preferably, it is 10-40 mass%, Most preferably, it is 15-35 mass%. When the content is less than 1% by mass, in order to obtain a predetermined viscosity index improvement effect, the amount of the lubricating oil additive composition blended in the lubricating oil composition increases, and the distribution efficiency tends to be impaired. In addition, the manufacturing cost of the lubricating oil composition may increase. On the other hand, when the content exceeds 70% by mass, the handling property of the lubricating oil additive composition is impaired, and good workability tends to be not obtained in the manufacturing operation of the lubricating oil composition.

  The lubricating oil additive composition of the present embodiment contains (B) a diluent (hereinafter sometimes referred to as “component (B)”). (B) Mineral oil, synthetic oil, and a mixture thereof are mentioned as a diluent, However, It is preferable that it is a mineral oil type diluent.

  Specifically, as mineral oil, a lubricating oil fraction obtained by distillation under reduced pressure of atmospheric residual oil obtained by atmospheric distillation of crude oil can be desolvated, solvent extracted, hydrocracked, and solvent dewaxed. , Purified by performing one or more treatments such as hydrorefining. Moreover, the lubricating base oil manufactured by the method of isomerizing the GTL WAX (gas-tree wax) manufactured by wax isomerized mineral oil, a Fischer-Tropsch process, etc. is mentioned.

  Synthetic oils include poly α-olefins or hydrides thereof, isobutene oligomers or hydrides thereof, isoparaffins, alkylbenzenes, alkylnaphthalenes, diesters (ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, ditridecyl 2-ethylhexyl sebacate), polyol ester (trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyoxyalkylene glycol, dialkyldiphenyl ether, polyphenyl Examples include ether. Among these, hydrocarbon synthetic oil is preferable, and poly α-olefin is particularly preferable. Examples of poly α-olefins include α-olefin oligomers or co-oligomers (such as 1-octene oligomers, decene oligomers, ethylene-propylene co-oligomers) having 2 to 32 carbon atoms, preferably 6 to 16 carbon atoms, and hydrides thereof. It is done.

  (B) The diluent may be mineral oil, synthetic oil, or any mixture of two or more oils selected from these. For example, 1 or more types of mineral oil, 1 or more types of synthetic oil, the mixed oil of 1 or more types of mineral oil and 1 or more types of synthetic oil is mentioned.

Kinematic viscosity at 100 ° C. of (B) diluent is preferably 1.5 to 10 mm ² / s, more preferably 1.8~8.0mm ² / s, 2.0~6. it is particularly preferred to be 0 mm ² / s and more preferably 2.5 to 5.0 mm ² / s. (B) When the kinematic viscosity at 100 ° C. of the diluent is less than 1.5 mm ² / s, the evaporation loss of the resulting lubricating oil composition tends to increase. Moreover, when this kinematic viscosity exceeds 10 mm < ² > / s, there exists a tendency for the dissolving power with respect to (A) component to be impaired.

(B) it is preferred that the% C _A of the diluent is 3 or less, more preferably 2.5 or less, further preferably 2.0 or less, and particularly preferably 1.5 or less . (B) exceeds% C _A is 3 diluents tend to heat and oxidation stability of a lubricating oil additive composition may be impaired. Incidentally, (B)% _{C A} diluent may be zero.

“% C _A ” in the present specification means the ratio (percentage) of the aromatic carbon number to the total carbon number, which is determined by a method (ndM ring analysis) based on ASTM D 3238-85.

  (B) The sulfur content of the diluent is preferably 0.05% by mass or less, more preferably 0.04% by mass, further preferably 0.03% by mass or less, and It is particularly preferable that the content be 02% by mass or less. (B) When the sulfur content of the diluent exceeds 0.05% by mass, the heat / oxidation stability of the lubricating oil additive composition tends to be impaired.

  Usually, the sulfur content of a mineral oil-based diluent depends on the sulfur content of the raw material. On the other hand, when a raw material that does not substantially contain sulfur such as a synthetic wax component obtained by a Fischer-Tropsch reaction or the like is used, a diluent that does not substantially contain sulfur can be obtained. In addition, when using raw materials containing sulfur such as slack wax obtained in the refining process of lubricating base oil and microwax obtained in the refined wax process, the sulfur content in the resulting mineral oil-based diluent is usually 0.01. It becomes mass% or more. In addition, the "sulfur content" in this specification means the sulfur content measured based on JISK2541-1996.

  (B) Although there is no restriction | limiting in particular about the viscosity index of a diluent, 80 or more are preferable, 100 or more are more preferable, 120 or more are further more preferable. There is no restriction | limiting in particular about the upper limit of a viscosity index, The thing of about 135-180 like a normal paraffin, slack wax, GTL wax, etc. or the isoparaffin type mineral oil which isomerized these can also be used. When the viscosity index of the diluent is less than 80, the heat / oxidation stability of the lubricating oil additive composition tends to be impaired.

  The content of the diluent (B) in the lubricating oil additive composition is preferably 1 to 98% by mass, more preferably 10 to 95% by mass, based on the total amount of the lubricating oil additive composition. More preferably, it is 20-90 mass%, and it is especially preferable that it is 30-85 mass%. When the content is less than 1% by mass, the handling property of the lubricating oil additive composition is impaired, and there is a tendency that good workability cannot be obtained in the manufacturing operation of the lubricating oil composition. Further, when the mixing ratio exceeds 98% by mass, the amount of the lubricating oil additive composition added to the lubricating oil composition is increased in order to obtain a predetermined viscosity index improving effect, and the distribution efficiency is impaired. There is a tendency for the trend and the lubricant production costs to increase.

  The lubricating oil additive composition of this embodiment contains (C) an ester compound having a carbon / oxygen atom number ratio (C / O ratio) of 10 or less (hereinafter sometimes referred to as “component (C)”). .

  The lubricating oil additive composition comprises, as component (C), (C1) an ester compound of a polyhydric alcohol having a C / O ratio of 10 or less, (C2) an ester compound of a polyvalent carboxylic acid having a C / O ratio of 10 or less, ( C3) It preferably contains a monoester compound having a C / O ratio of 10 or less, and (C1) more preferably contains an ester compound of a polyhydric alcohol having a C / O ratio of 10 or less.

(C-1) As an ester compound of a polyhydric alcohol having a C / O ratio of 10 or less, specifically, an ester compound of a 2-10 valent, preferably 2-6 valent polyhydric alcohol and a carboxylic acid is used. .
As the polyhydric alcohol, for example, those having 2 to 10 valences, preferably 2 to 6 valences are used. Specific examples of the 2 to 10 polyhydric alcohol include, for example, ethylene glycol, diethylene glycol, polyethylene glycol (3 to 15 mer of ethylene glycol), propylene glycol, dipropylene glycol, and polypropylene glycol (3 to 15 of propylene glycol). Monomer), 1,3-propanediol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,2-propanediol, 2-methyl-1,3 -Dihydric alcohols such as propanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, neopentylglycol; glycerin, polyglycerin (glycerin 2- Octamers such as diglycerin, triglyceride Phosphorus, tetraglycerin, etc.), trimethylolalkanes (trimethylolethane, trimethylolpropane, trimethylolbutane, etc.) and their 2- to 8-mer, pentaerythritol and their 2- to 4-mer, 1,2,4- Butanetriol, 1,3,5-pentanetriol, 1,2,6-hexanetriol, 1,2,3,4-butanetetrol, sorbitol, sorbitan, sorbitol glycerin condensate, adonitol, arabitol, xylitol, mannitol, etc. Polysaccharides of xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, sugars, and mixtures thereof That.
In order to maintain better fluidity and maintain excellent oxidation stability and hydrolysis stability when blended in a lubricating oil, the polyhydric alcohols may be trimethylolalkane and pentaerythritol. More preferred.

  Specific examples of carboxylic acids used for esterification of polyhydric alcohols include hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, and hexadecanoic acid. , Saturated fatty acids such as heptadecanoic acid, octadecanoic acid, nonadecanoic acid, icosanoic acid, heicosanoic acid, docosanoic acid, tricosanoic acid, tetracosanoic acid, pentacosanoic acid, hexacosanoic acid, heptacosanoic acid, octacosanoic acid, nonacosanoic acid, triacontanoic acid; , Heptenoic acid, octenoic acid, nonenoic acid, decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, heptadecenoic acid, octadecenoic acid, nonadecenoic acid, icosenic acid, henicosenic acid, docosenoic acid, Rikosen acid, tetracosenoic acid, pentacosenoic acid, hexacosenoic acid, heptacosenoic acid, octacosenoic acid, nonacosenoic acid, unsaturated fatty acids such as triacontene acid, and mixtures of two or more thereof. These carboxylic acids may be linear or branched. In order to maintain better fluidity, it is preferably a linear carboxylic acid, preferably a carboxylic acid having 1 to 20 carbon atoms, and a carboxylic acid having 1 to 17 carbon atoms. Is more preferable, a carboxylic acid having 1 to 15 carbon atoms is more preferable, a carboxylic acid having 1 to 12 carbon atoms is particularly preferable, and a carboxylic acid having 1 to 10 carbon atoms is most preferable. preferable.

(C2) As an ester compound of a polyvalent carboxylic acid having a C / O ratio of 10 or less, an ester compound of a 2 to 10-valent, preferably 2 to 6-valent polyvalent carboxylic acid and an alcohol is used. Specifically, dicarboxylic acids having 1 to 30 carbon atoms such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, etc. Tricarboxylic acids having 1 to 30 carbon atoms such as acid, citric acid and aconitic acid are preferred.
A polyvalent carboxylic acid having 1 to 20 carbon atoms is more preferred, a polyvalent carboxylic acid having 1 to 15 carbon atoms is more preferred, a polyvalent carboxylic acid having 1 to 15 carbon atoms is particularly preferred, and a polyvalent carboxylic acid having 1 to 15 carbon atoms is preferred. Carboxylic acid is most preferable because it can improve the fluidity.

  Specifically as alcohol used for esterification of polyhydric carboxylic acid, for example, it is C1-C24, Preferably it is 1-20, More preferably, it is 1-17, More preferably, it is 1-15, Most preferably, it is 1-1. 12, most preferably 1-10 are used. The alcohol may be linear or branched, and may be saturated or unsaturated, but is more preferably a linear alcohol and is saturated. It is more preferable. Examples of the alcohol having 1 to 24 carbon atoms include methanol, ethanol, linear or branched propanol, linear or branched butanol, linear or branched pentanol, linear or branched. Hexanol, linear or branched heptanol, linear or branched octanol, linear or branched nonanol, linear or branched decanol, linear or branched undecanol, linear Linear or branched dodecanol, linear or branched tridecanol, linear or branched tetradecanol, linear or branched pentadecanol, linear or branched hexadecanol, straight Linear or branched heptadecanol, linear or branched octadecanol, linear or branched nonadecanol, linear or branched icosanol, straight Jo or branched Hen'ikosanoru, linear or branched Torikosanoru, such as linear or branched tetracosanol, and mixtures thereof.

  (C3) Specific examples of monoester compounds having a C / O ratio of 10 or less include esters of carboxylic acid having 1 to 18 carbon atoms such as methyl oleate and methyl stearate and methyl alcohol, and carbon number 1 Ester of carboxylic acid having 1 to 17 carbon atoms and alcohol having 1 to 2 carbon atoms, ester of carboxylic acid having 1 to 16 carbon atoms and alcohol having 1 to 3 carbon atoms, carboxylic acid having 1 to 15 carbon atoms and carbon number 1 Examples are ester compounds in which a carboxylic acid having 1 to 18 carbon atoms and an alcohol having 1 to 18 carbon atoms, such as an ester of ˜4 alcohol, are combined so as to have a C / O ratio of 10 or less.

  The C / O ratio of the component (C) needs to be 10 or less, preferably 8 or less, and more preferably 7 or less. A C / O ratio exceeding 10 is not preferable because the effect of improving fluidity is inferior. The lower limit of the C / O ratio is not particularly limited, but is preferably 0.5 or more, more preferably 1 or more, further preferably 2 or more, and more preferably 3 or more. . By setting the C / O ratio to 0.5 or more, the solubility in the lubricating oil can be improved, and the effect tends to be exhibited in coexistence with fluidity.

  (C) The ester compound having a C / O ratio of 10 or less preferably has a carbon number of 100 or less, more preferably a carbon number of 70 or less, and more preferably a carbon number in that the fluidity can be further improved. It is more preferably 50 or less, particularly preferably 40 or less, and most preferably 30 or less.

(C) The kinematic viscosity at 100 ° C. of the ester compound having a C / O ratio of 10 or less is preferably 1 mm ² / s or more, and more preferably 2 mm ² / s or more. The kinematic viscosity at 100 ° C. is preferably 20 mm ² / s or less, more preferably 15 mm ² / s or less, still more preferably 10 mm ² / s or less, and 7 mm ² / s or less. particularly preferably at, and most preferably not more than ^{5 mm} 2 / s. By setting the kinematic viscosity at 100 ° C. to 1 mm ² / s or higher, the evaporability when added to the lubricating oil can be kept low. Moreover, the ability to improve fluidity can be increased by setting the kinematic viscosity at 100 ° C. to 20 mm ² / s or less.

  (C) The viscosity index of the ester compound having a C / O ratio of 10 or less is preferably 200 or less, more preferably 180 or less, further preferably 170 or less, and further preferably 160 or less. Preferably, it is 150 or less. The viscosity index is preferably 0 or more, more preferably 30 or more, further preferably 50 or more, particularly preferably 70 or more, and most preferably 100 or more. By setting the viscosity index to 0 or more, the viscosity index when added to the lubricating oil can be increased to improve fuel economy. Moreover, the ability to improve fluidity can be enhanced by setting the viscosity index to 200 or less.

  The content of the ester compound having a (C) C / O ratio of 10 or less in the lubricating oil additive composition is preferably 0.1 to 50% by mass based on the total amount of the lubricating oil additive composition. More preferably, it is -40 mass%, It is further more preferable that it is 3-30 mass%, It is especially preferable that it is 5-20 mass%. When the content is less than 0.1% by mass, the handling property of the lubricating oil additive composition is impaired, and there is a tendency that good workability cannot be obtained in the manufacturing operation of the lubricating oil composition. On the other hand, when the content exceeds 50% by mass, the amount of the lubricating oil additive composition blended with the lubricating oil composition is increased in order to obtain a predetermined viscosity index improving effect, and high logistics efficiency is impaired. There is a tendency that the manufacturing cost of lubricating oil increases.

Moreover, the manufacturing method of the lubricating oil additive composition of the present invention includes (A) a poly (meth) acrylate-based compound, (B) a diluent, and (C) an ester compound having a C / O ratio of 10 or less, The process of mixing. As preferable embodiment, a manufacturing method provided with the process shown to following (1)-(3) can be illustrated.
(1) In component (C) heated to 50 to 60 ° C., component (A) was added and dissolved by stirring to prepare a premix, and this premix was heated to 50 to 60 ° C. (B ) Add to ingredients and stir and mix.
(2) A mixture of the component (B) and the component (C) is heated to, for example, 50 to 60 ° C., and the component (A) is added and dissolved by stirring.
(3) After the production of the component (A), the component (A) is heated to 50 to 60 ° C., and the components (B) and (C) are added to the heated component (A) and stirred and dissolved. To do.

  The lubricating oil additive composition of the present embodiment thus obtained is blended with a lubricating base oil having predetermined properties so as to satisfy the target properties. Thus, a lubricating oil composition containing the lubricating oil additive composition and the lubricating base oil can be obtained. The additive composition for lubricating oil of the present embodiment functions as a viscosity index improver for various lubricating oil compositions. In addition, a lubricating oil composition in which this lubricating oil additive composition is blended is sufficiently excellent in low temperature characteristics.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

[Examples 1 to 4, Comparative Examples 1 to 5]
In order to prepare a lubricating oil additive composition, the following raw materials were prepared.
Component (A) Polymethacrylate (non-dispersed, weight average molecular weight: 400,000, PSSI: 20)
Component (B) Hydrocracked mineral oil (kinematic viscosity at 100 ° C .: 4.1 mm ² / s,% C _A : 0, sulfur content: 0.00% by mass)
(C) Component C-1: 2-ethylhexyl azelate (C / O ratio 6.3)
C-2: Trimethylolpropane ester (100 ° C. kinematic viscosity 4.3 mm ² / s, viscosity index 140, C / O ratio 6.0)
C-3: ester of pentaerythritol and pentanoic acid (100 ° C. kinematic viscosity 3.6 mm ² / s, viscosity index 113, C / O ratio 1.9)
C-4: ester of neopentyl glycol and isononanoic acid (100 ° C. kinematic viscosity 3.1 mm ² / s, C / O ratio 5.8)
Component (D) (Comparative component)
D-1: Neopentyl glycol dioleate (100 ° C. kinematic viscosity 5.9 mm ² / s, viscosity index 206, C / O ratio 10.3)
D-2: Octyl stearate (100 ° C. kinematic viscosity 3.1 mm ² / s, viscosity index 166, C / O ratio 13)
D-3: 2-ethylhexyl oleate (100 ° C. kinematic viscosity 2.7 mm ² / s, viscosity index 185, C / O ratio 13)
D-4: Alkylbenzene

  A lubricating oil additive composition having the composition shown in Table 1 was produced by blending the above raw materials. Specifically, in the component (B) heated to 50 to 60 ° C., the component (A) was added and dissolved by stirring to prepare a premix. And (C) component was added and stirred and mixed in the premix heated at 50-60 degreeC, and the lubricating oil additive composition was manufactured.

  The fluidity of the lubricating oil additive composition of each example and each comparative example was evaluated by the fluidity test shown below. The evaluation results are as shown in Table 1.

(Fluidity test)
(1) In a 50 mL beaker, 7 g of the lubricating oil additive composition produced as a sample was collected, and the lubricating oil additive composition was heated to 40 ° C. in a thermostatic bath.
(2) A 50 mL beaker was allowed to stand, and the liquid level (horizontal plane) of the sample was used as the reference position. Thereafter, the time required for the sample to flow 1 cm and 2 cm in the horizontal direction from the reference position after the 50 mL beaker was tilted sideways was measured.

When the content ratio of the component (A) is substantially constant, the lubricating oil additive compositions of Examples 1 to 4 are replaced with the components (D) instead of the component (C) in Comparative Example 1 and (C) (D). ) The fluidity was superior to the lubricating oil additive compositions of Comparative Examples 2 to 5 to which the component was added. Since the content of the component (A) in the lubricating oil additive compositions of Examples 1 to 4 is sufficiently high, when added to a lubricating base oil, an excellent viscosity index improving effect is exhibited.

Claims (6)

  A lubricating oil additive composition comprising a poly (meth) acrylate compound, a diluent, and an ester compound having a carbon / oxygen atom number ratio of 10 or less.   The ester compound is an ester compound of a polyhydric alcohol having a carbon / oxygen atom number ratio of 10 or less, an ester compound of a polyvalent carboxylic acid having a carbon / oxygen atom number ratio of 10 or less, and a carbon / oxygen atom ratio of 10 The lubricating oil additive composition according to claim 1, which is at least one compound selected from the group consisting of the following monoester compounds.   The lubricating oil additive composition according to claim 1 or 2, wherein the ester compound is an ester compound of a polyhydric alcohol and a carboxylic acid having 17 or less carbon atoms.   A method for producing a lubricating oil additive composition comprising a step of mixing a poly (meth) acrylate-based compound, a diluent, and an ester compound having a carbon / oxygen atom number ratio of 10 or less.   The lubricating oil composition containing lubricating base oil and the lubricating oil additive composition as described in any one of Claims 1-3. The manufacturing method of a lubricating oil composition provided with the process of mixing lubricating base oil and the lubricating oil additive composition as described in any one of Claims 1-3.