JP6326355B2 - Lubricating oil composition - Google Patents

Description

  The present invention relates to a lubricating oil composition for an internal combustion engine, and particularly to a lubricating oil composition for a high-power internal combustion engine.

  Petroleum products generally have a so-called viscosity temperature dependency in which the viscosity changes greatly when the temperature changes. For example, it is preferable that the temperature dependence of the viscosity is small in a lubricating oil or the like used for an automobile or the like. Therefore, in the lubricating oil, for the purpose of reducing the temperature dependency of the viscosity, a certain polymer that is soluble in the lubricating oil base is used as a viscosity modifier (also referred to as a viscosity index improver). In recent years, OCP (olefin copolymer) has been widely used as such a viscosity modifier, and various improvements as exemplified in Patent Document 1 have been made for OCP in order to further improve the performance of the lubricating oil.

  On the other hand, improvement in fuel consumption of an internal combustion engine is strongly demanded in recent years with increasing demands for reducing environmental loads. One of the countermeasures is a technology for improving the fuel efficiency of engine oil. In ordinary automobiles, lowering the viscosity of engine oil for the purpose of reducing torque by lowering the viscosity is progressing. However, in high output engines such as large displacement engines such as construction machinery and heavy machinery and marine crosshead diesel engine oil, a large load is applied to the engine piston and crank. In the viscosity standard defined by SAE (Society of Automotive Engineers) shown in Table 1, high-viscosity engine oil of 40 or more is often used, and it is difficult to reduce the viscosity. Also, for ordinary cars, motorcycles for racing in motorcycles, and large-displacement motorcycles such as large motorcycles, the engine is used in a higher rotation range than ordinary cars and small and medium-sized motorcycles. Since the engine oil is heated to a higher temperature and the viscosity is lowered, a high viscosity engine oil is used.

  In engine oils, viscosity index improvers are used to maintain the proper viscosity of lubricating oils at high temperatures, but general viscosity index improvers used in ordinary engine oils for automobiles have a relatively high molecular weight and are due to shear stress. Molecular cutting occurs, and the viscosity of the lubricating oil tends to decrease. For this reason, it is unsuitable to use a general viscosity index improver for a high-viscosity engine oil used under severe conditions as described above. For this reason, a viscosity modifier with a relatively low molecular weight is used, but although viscosity reduction due to shearing can be suppressed, it is inferior in viscosity index improving ability, so the temperature dependence of viscosity is large, specifically in a low temperature environment. Is poor in fluidity of the lubricating oil at 40 ° C. or lower, and the stirring resistance at the start of the internal combustion engine is extremely large compared to the engine oil for ordinary automobiles, which adversely affects the fuel consumption of the internal combustion engine.

International Publication No. 00/34420

  In view of such problems in the prior art, the problem to be solved by the present invention is that the temperature dependence of the viscosity is low while maintaining high shear stability, from the viewpoint of fuel economy and energy saving of automobiles, An object of the present invention is to provide a lubricating oil composition for an internal combustion engine having excellent fluidity at 40 ° C. or less and low stirring resistance to the engine.

  As a result of intensive studies to develop a lubricating oil composition having excellent performance, the present inventors contain a specific ethylene-α-olefin copolymer for a specific lubricating base oil, It has been found that a lubricating oil composition satisfying the conditions can solve the above-mentioned problems, and the present invention has been completed. Specifically, the present invention includes the following aspects.

[1] A lubricating base oil and an ethylene-α-olefin copolymer (C) having the following characteristics (C1) to (C5), and a kinematic viscosity at 100 ° C. of 12.5 mm ² / s And less than 26.1 mm ² / s,
The internal combustion engine, wherein the lubricating base oil is composed of a mineral oil (A) having the following characteristics (A1) to (A3) and / or a synthetic oil (B) having the characteristics (B1) to (B3): Lubricating oil composition.
(A1) Kinematic viscosity at 100 ° C. is ² to 10 mm ² / s (A2) Viscosity index is 95 or more (A3) Pour point is −10 ° C. or less (B1) Kinematic viscosity at 100 ° C. is but the range that is 1~10mm ² / s (B2) that a viscosity index of 120 or more (B3) pour point of -30 ° C. or less (C1) an ethylene content of 30 to 85 mol% (C2) Kinematic viscosity at 100 ° C. is 10 to 5,000 mm ² / s (C3) Measured by gel permeation chromatography (GPC) and obtained in terms of polystyrene, molecular weight distribution (Mw / Mn) is 2.5 or less (C4) The following formula [1]

(Wherein P _E represents the mole fraction of ethylene component, P _O represents the mole fraction of α-olefin component, and P _OE represents the mole fraction of ethylene-α-olefin chains of all dyad chains. Show.)
(C5) The amount of unsaturated bonds measured by ¹ H-NMR is less than 0.5 per 1000 carbon atoms. [2] The ethylene-α -The lubricating oil composition for internal combustion engines according to the above [1], wherein the ethylene content of the olefin copolymer (C) is in the range of 40 to 70 mol%.

[3] The lubricating oil composition for internal combustion engines according to the above [1] or [2], wherein the ethylene-α-olefin copolymer (C) has a kinematic viscosity at 100 ° C. of 35 to 2,500 mm ² / s. .
[4] The lubricating oil composition for internal combustion engines according to any one of [1] to [3], wherein the α-olefin of the ethylene-α-olefin copolymer (C) is propylene.
[5] The lubricating oil composition for internal combustion engines according to any one of [1] to [4], wherein the synthetic oil (B) contains an ester and a synthetic oil other than the ester.
[6] A diesel engine oil comprising the lubricating oil composition for an internal combustion engine according to any one of [1] to [5].
[7] The lubricating oil composition for internal combustion engines according to any one of the above [1] to [5], which has a total base number of at least 20 mg-KOH / g.

  The lubricating oil composition of the present invention maintains a high shear stability as compared with conventional lubricating oils containing the same lubricating base oil, and exhibits a very excellent temperature viscosity characteristic and excellent low temperature fluidity. It contributes to fuel saving of internal combustion engine oil.

Hereinafter, the lubricating oil composition for internal combustion engines according to the present invention (hereinafter also simply referred to as “lubricating oil composition”) will be described in detail.
The lubricating oil composition for internal combustion engines according to the present invention contains a lubricating base oil and an ethylene-α-olefin copolymer (C), and has a kinematic viscosity at 100 ° C. of 12.5 mm ² / s or more and 26.1 mm. It is less than ² / s, and the lubricating base oil is composed of mineral oil (A) and / or synthetic oil (B).

<Lubricant base oil>
The lubricating base oil used in the present invention differs in performance and quality such as viscosity characteristics, heat resistance, and oxidation stability depending on its production method and purification method. API (American Petroleum Institute) classifies lubricant base oils into five types of groups I, II, III, IV, and V. These API categories are defined in API Publication 1509, 15th Edition, Appendix E, April 2002, as shown in Table 2.

<(A) Mineral oil>
The mineral oil (A) has the following features (A1) to (A3). The mineral oil (A) in the present invention belongs to groups I to III in the above-mentioned API category.

(A1) The kinematic viscosity at 100 ° C. is ² to 10 mm ² / s. The value of this kinematic viscosity is measured according to the method described in JIS K2283. The kinematic viscosity at 100 ° C. of the mineral oil (A) is ^{2 to 10} mm ² / s, preferably 2.5 to 8 mm ² / s, more preferably 3.5 to 6.5 mm ² / s. When the kinematic viscosity at 100 ° C. is in this range, the lubricating oil composition of the present invention is excellent in terms of volatility and temperature viscosity characteristics.

(A2) Viscosity index is 95 or more The value of this viscosity index is measured according to the method described in JIS K2283. The viscosity index of the mineral oil (A) is 95 or more, preferably 105 or more, more preferably 120 or more. When the viscosity index is within this range, the lubricating oil composition of the present invention has excellent temperature viscosity characteristics.

(A3) The pour point is −10 ° C. or less. The value of the pour point is measured according to the method described in ASTM D97. The pour point of the mineral oil (A) is −10 ° C. or lower, preferably −12 ° C. or lower. When the pour point is in this range, the lubricating oil composition of the present invention has excellent low-temperature viscosity characteristics when the mineral oil (A) is used in combination with a pour point depressant.

  The quality of the mineral oil is as described above, and the above-described mineral oils of the respective qualities are obtained by the refining method. Specifically, as the mineral oil (A), a lubricating oil fraction obtained by distillation under reduced pressure of atmospheric residual oil obtained by atmospheric distillation of crude oil is subjected to solvent removal, solvent extraction, hydrocracking. Examples thereof include those refined by one or more treatments such as solvent dewaxing and hydrorefining, or lubricating base oils such as wax isomerized mineral oil.

  Gas-to-liquid (GTL) base oil obtained by the Fischer-Tropsch process is also a base oil that can be suitably used as Group III mineral oil. Such GTL base oils are sometimes treated as Group III + lubricating base oils, for example, patent documents EP0776959, EP0668342, WO97 / 21788, WO00 / 15736, WO00 / 14188, WO00 / 14187, WO00 / 14183. , WO 00/14179, WO 00/08115, WO 99/41332, EP 1029029, WO 01/18156 and WO 01/57166.

  In the lubricating oil composition of the present invention, the mineral oil (A) may be used alone as the lubricating base oil, or two or more selected from the synthetic oil (B) and the mineral oil (A). An arbitrary mixture of lubricating oils may be used.

<(B) Synthetic oil>
The synthetic oil (B) has the following characteristics (B1) to (B3). The synthetic oil (B) in the present invention belongs to Group IV or Group V in the above-mentioned API category.

(B1) The kinematic viscosity at 100 ° C. is 1 to 10 mm ² / s. The value of this kinematic viscosity is measured according to the method described in JIS K2283. The kinematic viscosity at 100 ° C. of the synthetic oil (B) is 1 to 10 mm ² / s, preferably ² to 8 mm ² / s, and more preferably 3.5 to ⁶ mm ² / s. When the kinematic viscosity at 100 ° C. is in this range, the lubricating oil composition of the present invention is excellent in terms of volatility and temperature viscosity characteristics.

(B2) Viscosity index is 120 or more The value of this viscosity index is measured according to the method described in JIS K2283. The viscosity index of the synthetic oil (B) is 120 or more, preferably 125 or more. When the viscosity index is within this range, the lubricating oil composition of the present invention has excellent temperature viscosity characteristics.

(B3) The pour point is −30 ° C. or less. The value of the pour point is measured according to the method described in ASTM D97. The pour point of the synthetic oil (B) is −30 ° C. or lower, preferably −40 ° C. or lower, more preferably −50 ° C. or lower, and further preferably −60 ° C. or lower. When the pour point is within this range, the lubricating oil composition of the present invention has excellent low temperature viscosity characteristics.

  Poly-α-olefins belonging to Group IV are acid catalysts as described in U.S. Pat. No. 3,780,128, U.S. Pat. No. 4,032,591, and JP-A-1-163136. Can be obtained by oligomerizing a higher α-olefin. Among these, as the poly-α-olefin, a low molecular weight oligomer of at least one olefin selected from olefins having 8 or more carbon atoms can be used. When poly-α-olefin is used as the lubricating base oil, a lubricating oil composition having extremely excellent temperature viscosity characteristics, low temperature viscosity characteristics, and heat resistance can be obtained.

Poly -α- olefins, industrially also available, 100 ° C. kinematic viscosity are commercially available in 2mm ² / s~10mm ² / s. For example, NEXBASE2000 series manufactured by NESTE, Spectrayn manufactured by ExxonMobil Chemical, Durasyn manufactured by Ineos Olymmers, Synfluid manufactured by Chevron Phillips Chemical, and the like can be mentioned.

  Examples of the synthetic oil belonging to Group V include alkylbenzenes, alkylnaphthalenes, isobutene oligomers or hydrides thereof, paraffins, polyoxyalkylene glycols, dialkyldiphenyl ethers, polyphenyl ethers, esters, and the like.

  Most of alkylbenzenes and alkylnaphthalenes are usually dialkylbenzene or dialkylnaphthalene having an alkyl chain length of 6 to 14 carbon atoms. Such alkylbenzenes or alkylnaphthalenes are free of benzene or naphthalene and olefin. Manufactured by a Dell Kraft alkylation reaction. The alkylated olefin used in the production of alkylbenzenes or alkylnaphthalenes may be a linear or branched olefin or a combination thereof. These production methods are described, for example, in US Pat. No. 3,909,432.

The ester is preferably a fatty acid ester from the viewpoint of compatibility with the ethylene-α-olefin copolymer (C).
The fatty acid ester is not particularly limited, and examples thereof include the following fatty acid esters consisting only of carbon, oxygen, and hydrogen. For example, a monoester produced from a monobasic acid and an alcohol; from a dibasic acid and an alcohol, Or diesters made from diols and monobasic acids or acid mixtures; diols, triols (eg trimethylolpropane), tetraols (eg pentaerythritol), hexaols (eg dipentaerythritol) and the like and monobasic acids or acid mixtures And polyol ester produced by reacting with. Examples of these esters include ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, tridecyl pelargonate, di-2-ethylhexyl adipate, di-2 -Ethylhexyl azelate, trimethylolpropane caprylate, trimethylolpropane pelargonate, trimethylolpropane triheptanoate, pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate, pentaerythritol tetraheptanoate, etc. .

  From the viewpoint of compatibility with the ethylene-α-olefin copolymer (C), the alcohol moiety constituting the ester is preferably an alcohol having a bifunctional or higher hydroxyl group, and the fatty acid moiety is a fatty acid having 8 or more carbon atoms. Is preferred. However, fatty acids having a carbon number of 20 or less, which are industrially easily available, are superior in terms of production cost. The fatty acid constituting the ester may be one kind, and even when a fatty acid ester produced using two or more kinds of acid mixtures is used, the effects of the present invention are sufficiently exhibited. More specifically, examples of the fatty acid ester include trimethylolpropane lauric acid stearic acid mixed triester and diisodecyl adipate, and these include saturated hydrocarbon components such as ethylene-α-olefin copolymer (C) and the like. From the viewpoint of compatibility with an antioxidant having a polar group, a corrosion inhibitor, an antiwear agent, a friction modifier, a pour point depressant, a rust inhibitor, an antifoaming agent, and the like, which will be described later.

  When the lubricating oil composition of the present invention uses a synthetic oil (B), particularly poly-α-olefin, as the lubricating base oil, 5 to 20 fatty acid esters when the entire lubricating oil composition is 100% by mass. It is preferable to contain in the quantity of the mass%. By containing 5 mass% or more fatty acid ester, favorable compatibility is obtained with respect to lubricating oil sealing materials such as resins and elastomers in various internal combustion engines and industrial machines. Specifically, swelling of the lubricating oil sealing material can be suppressed. From the viewpoint of oxidation stability or heat resistance, the amount of ester is preferably 20% by mass or less. When mineral oil is contained in the lubricating oil composition, the fatty acid ester is not necessarily required because the mineral oil itself has the effect of suppressing swelling of the lubricating oil sealant.

<(C) ethylene-α-olefin copolymer>
The ethylene-α-olefin copolymer (C) has the following characteristics (C1) to (C5).
(C1) The ethylene content is 30 to 85 mol%. The ethylene content of the ethylene-α-olefin copolymer (C) is usually 30 to 85 mol%, preferably 40 to 70 mol%, particularly preferably 45. -65 mol%. If it is too low, the viscosity temperature characteristic of the lubricating oil composition will deteriorate, and if it is higher than this, crystallinity may be developed due to the extension of the ethylene chain in the molecule. Viscosity characteristics deteriorate.

The ethylene content of the ethylene-α-olefin copolymer (C) is measured by ¹³ C-NMR according to the method described in “Polymer Analysis Handbook” (published by Asakura Shoten, P163-170). Moreover, it is also possible to measure using the Fourier transform infrared spectroscopy (FT-IR) by making the sample calculated | required by this method into a known sample.

(C2) The kinematic viscosity at 100 ° C. is 10 to 5,000 mm ² / s. The value of this kinematic viscosity is measured by the method described in JIS K2283. The kinematic viscosity at 100 ° C. of the ethylene-α-olefin copolymer (C) is 10 to 5,000 mm ² / s, preferably 20 to 2,500 mm ² / s, more preferably 35 to 2,500 mm ² / s. More preferably, the thickness is 90 to 2,500 mm ² / s, and particularly preferably 300 to 2,500 mm ² / s. It is preferable that the kinematic viscosity at 100 ° C. of the ethylene-α-olefin copolymer (C) is within the above range from the viewpoint of the low-temperature viscosity characteristics of the lubricating oil composition.

(C3) The molecular weight distribution is 2.5 or less The molecular weight distribution of the ethylene-α-olefin copolymer (C) is measured by gel permeation chromatography (GPC) according to the method described later, and obtained by standard polystyrene conversion. It is calculated as the ratio (Mw / Mn) of the obtained weight average molecular weight (Mw) and number average molecular weight (Mn). This Mw / Mn is 2.5 or less, preferably 2.3 or less, more preferably 2.0 or less. When the molecular weight distribution exceeds this range, the viscosity of the lubricating oil composition changes due to the volatilization of low molecular weight components or the shear stability of the lubricating oil composition deteriorates when used in a high temperature environment. The molecular weight distribution of the ethylene-α-olefin copolymer (C) is preferably at least 1.4 or more. When the molecular weight distribution is in this range, the viscosity temperature characteristic and the low temperature viscosity characteristic of the lubricating oil composition are excellent.

(C4) B value is 1.1 or more The B value represented by the following formula [1] of the ethylene-α-olefin copolymer (C) is 1.1 or more, preferably 1.2 or more. is there.

In the formula [1], P _E represents the mole fraction of ethylene component, P 2 _O represents the mole fraction of α-olefin component, and P _OE represents the mole fraction of ethylene-α-olefin chain of all dyad chains. Indicates the rate.

  The larger the B value, the less the block chain, the more uniform the distribution of ethylene and α-olefin, and the narrower the composition distribution. The length of this block chain will affect the properties of the copolymer in terms of physical properties. The larger the B value, the shorter the block chain, and the pour point of the ethylene-α-olefin copolymer (C). Lowering, the lubricating oil composition exhibits good low temperature viscosity characteristics.

The B value is an index indicating the randomness of the copolymer monomer chain distribution in the copolymer. P _E , P _O and P _OE in the above formula [1] are measured by measuring a ¹³ C-NMR spectrum. C. Randall [Macromolecules, 15, 353 (1982)], J. Ray [Macromolecules, 10, 773 (1977)] et al.

Specific measurement conditions for the B value are as described in the examples.
(C5) The amount of unsaturated bonds measured by ¹ H-NMR is less than 0.5 per 1000 carbon atoms. Measured by ¹ H-NMR possessed by the molecule of the ethylene-α-olefin copolymer (C). The total number of double bonds derived from vinyl, vinylidene, disubstituted olefins and trisubstituted olefins (hereinafter also referred to as “unsaturated bond amount”) is less than 0.5 per 1000 carbon atoms. , Preferably less than 0.3, more preferably less than 0.2, and even more preferably less than 0.1. When the unsaturated bond amount is within the range, the heat resistance of the lubricating oil composition is improved. Specific measurement conditions for the amount of unsaturated bonds are as described in the examples.

The ethylene-α-olefin copolymer (C) preferably further has the characteristics of (C6).
(C6) No melting point observed

  The ethylene-α-olefin copolymer (C) preferably has no melting point observed by differential scanning calorimetry (DSC). Here, that the melting point (Tm) is not observed means that the heat of fusion (ΔH) (unit: J / g) measured by differential scanning calorimetry (DSC) is not substantially measured. The fact that the heat of fusion (ΔH) is not substantially measured means that no peak is observed in the differential scanning calorimeter (DSC) measurement, or the observed heat of fusion is 1 J / g or less. The melting point (Tm) and the heat of fusion (ΔH) of the ethylene-α-olefin copolymer (C) were measured by differential scanning calorimetry (DSC), cooled to −100 ° C. and then heated at a rate of 10 ° C./min. When the temperature is raised to 150 ° C., the DSC curve is obtained with reference to JIS K7121. If no melting point is observed, no crystal component is produced at low temperatures, so that the increase in low-temperature viscosity is suppressed, and the lubricating oil composition is excellent in low-temperature viscosity characteristics.

  Examples of the α-olefin used in the ethylene-α-olefin copolymer (C) include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, C3-C20 straight chain such as 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, vinylcyclohexane or the like A branched α-olefin can be exemplified. The α-olefin is preferably a linear or branched α-olefin having 3 to 10 carbon atoms, more preferably propylene, 1-butene, 1-hexene and 1-octene, and the resulting copolymer was used. Propylene is most preferred from the viewpoint of the shear stability of the lubricating oil composition. These α-olefins can be used alone or in combination of two or more.

  In addition, the polymerization can also proceed by coexisting at least one other monomer selected from a polar group-containing monomer, an aromatic vinyl compound, and a cyclic olefin in the reaction system. The other monomer can be used in an amount of, for example, 20 parts by mass or less, preferably 10 parts by mass or less based on 100 parts by mass in total with ethylene and the α-olefin having 3 to 20 carbon atoms.

  Examples of the polar group-containing monomer include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid and maleic anhydride, and metal salts such as sodium salts thereof, methyl acrylate, ethyl acrylate, acrylic acid α, β-unsaturated carboxylic esters such as n-propyl, methyl methacrylate and ethyl methacrylate, vinyl esters such as vinyl acetate and vinyl propionate, unsaturated glycidyl such as glycidyl acrylate and glycidyl methacrylate, etc. Can be illustrated.

  Examples of the aromatic vinyl compound include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o, p-dimethylstyrene, methoxystyrene, vinylbenzoic acid, methyl vinylbenzoate, vinylbenzyl acetate, hydroxystyrene, Examples thereof include p-chlorostyrene, divinylbenzene, α-methylstyrene, and allylbenzene.

  Examples of the cyclic olefin include cyclic olefins having 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms such as cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, and tetracyclododecene.

  The production method of the ethylene-α-olefin copolymer (C) is not particularly limited, but from a vanadium compound and an organoaluminum compound as described in JP-B2-1163 and JP-B-2-7998. And a method using a vanadium catalyst. Further, as a method for producing a copolymer with high polymerization activity, metallocene compounds such as zirconocene and organoaluminum as described in JP-A-61-221207, JP-B-7-121969, and Japanese Patent No. 2796376. A method using a catalyst system composed of an oxy compound (aluminoxane) may be used, and the chlorine content of the resulting copolymer and 2,1-insertion of propylene can be reduced, which is more preferable. In the method using a vanadium catalyst, since a larger amount of chlorine compound is used as a co-catalyst than the method using a metallocene catalyst, a trace amount of chlorine may remain in the resulting ethylene-α-olefin copolymer (C). There is sex.

  On the other hand, in the method using a metallocene catalyst, chlorine is not substantially left, so that it is not necessary to consider the possibility of corrosion of metal parts in internal combustion engines, machines, and the like. The chlorine content is preferably 100 ppm or less, more preferably 50 ppm or less, further preferably 20 ppm or less, and particularly preferably 5 ppm or less. The chlorine content can be quantified by various known methods. The specific measurement method in the present invention is as described in the examples.

Further, the 2,1-insertion reduction of propylene makes it possible to further reduce the ethylene chain in the copolymer molecule and suppress the intramolecular crystallinity of ethylene, so that the viscosity temperature characteristics of the lubricating oil composition and Low temperature viscosity characteristics can be improved. The 2,1-insertion amount of propylene is determined by analysis of ¹³ C-NMR measurement according to the method described in JP-A-7-145212, preferably less than 1%, more preferably 0-0.5%, more Preferably it is 0 to 0.1%. Those in which no peak is observed in the range of 15.0 to 17.5 ppm are particularly preferable.

  In particular, by using the following method, an ethylene-α-olefin copolymer (C) having a good performance balance in terms of molecular weight control, molecular weight distribution, amorphousness and B value can be obtained.

  The ethylene-α-olefin copolymer (C) includes a crosslinked metallocene compound (a) represented by the following general formula [I], an organometallic compound (b-1), and an organoaluminum oxy compound (b-2). And ethylene and carbon in the presence of an olefin polymerization catalyst comprising at least one compound (b) selected from the group consisting of the compound (b-3) which reacts with the bridged metallocene compound (a) to form an ion pair. It can be produced by copolymerizing an α-olefin having a number of 3 to 20.

<Bridged metallocene compound>
The bridged metallocene compound (a) is represented by the above formula [I]. Y, M, R ^{1 to} R ¹⁴ , Q, n, and j in the formula [I] will be described below.

^{(Y, M, R 1 ~R} 14, Q, n and j)
Y is a group 14 atom, and examples thereof include a carbon atom, a silicon atom, a germanium atom, and a tin atom, preferably a carbon atom or a silicon atom, and more preferably a carbon atom.

M is a titanium atom, a zirconium atom or a hafnium atom, preferably a zirconium atom.
R ^{1 to} R ¹² are a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, a nitrogen-containing group, an oxygen-containing group, a halogen atom, or an atom or substituent selected from the group consisting of a halogen-containing group. These may be the same or different. Further, adjacent substituents from R ¹ to R ¹² may be bonded to each other to form a ring, or may not be bonded to each other.

  Here, as a C1-C20 hydrocarbon group, a C1-C20 alkyl group, a C3-C20 cyclic saturated hydrocarbon group, a C2-C20 chain unsaturated hydrocarbon group, Examples thereof include cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, alkylene groups having 1 to 20 carbon atoms, and arylene groups having 6 to 20 carbon atoms.

  Examples of the alkyl group having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, allyl, n-butyl, n-pentyl, and n-hexyl which are linear saturated hydrocarbon groups. Group, n-heptyl group, n-octyl group, n-nonyl group, n-decanyl group, etc., branched saturated hydrocarbon groups such as isopropyl group, isobutyl group, s-butyl group, t-butyl group, t-amyl group Group, neopentyl group, 3-methylpentyl group, 1,1-diethylpropyl group, 1,1-dimethylbutyl group, 1-methyl-1-propylbutyl group, 1,1-propylbutyl group, 1,1-dimethyl Examples include 2-methylpropyl group, 1-methyl-1-isopropyl-2-methylpropyl group, and cyclopropylmethyl group. Preferably carbon number of an alkyl group is 1-6.

  Examples of the cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, norbornenyl group, 1-adamantyl group, which are cyclic saturated hydrocarbon groups, 3-methylcyclopentyl group, 3-methylcyclohexyl group, 4-methylcyclohexyl group, which is a group in which a hydrogen atom of a cyclic saturated hydrocarbon group such as 2-adamantyl group is replaced with a hydrocarbon group having 1 to 17 carbon atoms, 4 Examples include -cyclohexylcyclohexyl group and 4-phenylcyclohexyl group. The number of carbon atoms of the cyclic saturated hydrocarbon group is preferably 5-11.

  Examples of the chain unsaturated hydrocarbon group having 2 to 20 carbon atoms include ethenyl group (vinyl group), 1-propenyl group, 2-propenyl group (allyl group) and 1-methylethenyl group (isopropenyl group) which are alkenyl groups. Examples thereof include ethynyl group, 1-propynyl group, 2-propynyl group (propargyl group) which are alkynyl groups. The chain unsaturated hydrocarbon group preferably has 2 to 4 carbon atoms.

  Examples of the cyclic unsaturated hydrocarbon group having 3 to 20 carbon atoms include cyclopentadienyl group, norbornyl group, phenyl group, naphthyl group, indenyl group, azulenyl group, phenanthryl group, anthracenyl group and the like, which are cyclic unsaturated hydrocarbon groups 3-methylphenyl group (m-tolyl group) and 4-methylphenyl group (p-tolyl group), which are groups in which a hydrogen atom of a cyclic unsaturated hydrocarbon group is replaced with a hydrocarbon group having 1 to 15 carbon atoms 4-ethylphenyl group, 4-t-butylphenyl group, 4-cyclohexylphenyl group, biphenylyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl group ( A cyclic hydrocarbon group having 3 to 19 carbon atoms or a cyclic unsaturated hydrocarbon group, such as a mesityl group) or the like. Benzyl group is a group which is replaced by a hydrocarbon group, such as cumyl group and the like. The number of carbon atoms of the cyclic unsaturated hydrocarbon group is preferably 6-10.

  Examples of the alkylene group having 1 to 20 carbon atoms include a methylene group, an ethylene group, a dimethylmethylene group (isopropylidene group), an ethylmethylene group, a methylethylene group, and an n-propylene group. Preferably carbon number of an alkylene group is 1-6.

  Examples of the arylene group having 6 to 20 carbon atoms include o-phenylene group, m-phenylene group, p-phenylene group, 4,4'-biphenylylene group and the like. The carbon number of the arylene group is preferably 6-12.

  Examples of the silicon-containing group include alkyl groups such as a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, and a triisopropylsilyl group, which are groups in which a carbon atom is replaced with a silicon atom in a hydrocarbon group having 1 to 20 carbon atoms. Examples thereof include arylsilyl groups such as silyl group, dimethylphenylsilyl group, methyldiphenylsilyl group, t-butyldiphenylsilyl group, pentamethyldisiranyl group, and trimethylsilylmethyl group. The alkylsilyl group preferably has 1 to 10 carbon atoms, and the arylsilyl group preferably has 6 to 18 carbon atoms.

Examples of the nitrogen-containing group, or an amino group, in a hydrocarbon group or a silicon-containing group having 1 to 20 carbon atoms mentioned above, = CH- group where structural unit is replaced by a nitrogen atom, is -CH _2-structural units carbon atoms Dimethyl which is a group in which a hydrocarbon group having 1 to 20 hydrocarbons is replaced by a nitrogen atom bonded thereto, or a group in which a —CH ₃ structural unit is replaced by a nitrogen atom or a nitrile group to which a hydrocarbon group having 1 to 20 carbon atoms is bonded Examples include amino group, diethylamino group, N-morpholinyl group, dimethylaminomethyl group, cyano group, pyrrolidinyl group, piperidinyl group, pyridinyl group, N-morpholinyl group and nitro group. As the nitrogen-containing group, a dimethylamino group and an N-morpholinyl group are preferable.

Examples of the oxygen-containing group include a hydroxyl group, a group having 1 to 20 carbon atoms, a silicon-containing group, or a nitrogen-containing group, in which the —CH ₂ — structural unit is replaced by an oxygen atom or a carbonyl group, or — A methoxy group, an ethoxy group, a t-butoxy group, a phenoxy group, a trimethylsiloxy group, a methoxyethoxy group, hydroxymethyl, which is a group in which the CH ₃ structural unit is replaced by an oxygen atom to which a hydrocarbon group having 1 to 20 carbon atoms is bonded. Group, methoxymethyl group, ethoxymethyl group, t-butoxymethyl group, 1-hydroxyethyl group, 1-methoxyethyl group, 1-ethoxyethyl group, 2-hydroxyethyl group, 2-methoxyethyl group, 2-ethoxyethyl Group, n-2-oxabutylene group, n-2-oxapentylene group, n-3-oxapentylene group, aldehyde group Examples include acetyl group, propionyl group, benzoyl group, trimethylsilylcarbonyl group, carbamoyl group, methylaminocarbonyl group, carboxy group, methoxycarbonyl group, carboxymethyl group, ethocarboxymethyl group, carbamoylmethyl group, furanyl group, and pyranyl group. The As the oxygen-containing group, a methoxy group is preferable.

Examples of halogen atoms include group 17 elements such as fluorine, chlorine, bromine and iodine.
Examples of the halogen-containing group include a trifluoromethyl group, tribromo, which is a group in which a hydrogen atom is substituted with a halogen atom in the above-described hydrocarbon group having 1 to 20 carbon atoms, silicon-containing group, nitrogen-containing group or oxygen-containing group. Examples include a methyl group, a pentafluoroethyl group, a pentafluorophenyl group, and the like.

Q is selected from the same or different combinations from a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an anionic ligand, and a neutral ligand capable of coordinating with a lone electron pair.
Details of the halogen atom and the hydrocarbon group having 1 to 20 carbon atoms are as described above. When Q is a halogen atom, a chlorine atom is preferable. When Q is a hydrocarbon group having 1 to 20 carbon atoms, the hydrocarbon group preferably has 1 to 7 carbon atoms.

  Examples of the anionic ligand include alkoxy groups such as methoxy group, t-butoxy group, and phenoxy group, carboxylate groups such as acetate and benzoate, and sulfonate groups such as mesylate and tosylate.

  Examples of neutral ligands that can be coordinated by a lone pair include organophosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, diphenylmethylphosphine, tetrahydrofuran, diethyl ether, dioxane, 1,2-dimethoxyethane, and the like. An ether compound etc. can be illustrated.

j is an integer of 1 to 4, preferably 2.
n is an integer of 1 to 4, preferably 1 or 2, and more preferably 1.
R ¹³ and R ¹⁴ are selected from the group consisting of a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an aryl group, a substituted aryl group, a silicon-containing group, a nitrogen-containing group, an oxygen-containing group, a halogen atom and a halogen-containing group. An atom or a substituent, which may be the same or different. R ¹³ and R ¹⁴ may be bonded to each other to form a ring, or may not be bonded to each other.

The details of the hydrocarbon group having 1 to 20 carbon atoms, the silicon-containing group, the nitrogen-containing group, the oxygen-containing group, the halogen atom and the halogen-containing group are as described above.
The aryl group partially overlaps with the example of the cyclic unsaturated hydrocarbon group having 3 to 20 carbon atoms described above, but is a phenyl group, 1-naphthyl group, 2-naphthyl which is a substituent derived from an aromatic compound. Groups, anthracenyl group, phenanthrenyl group, tetracenyl group, chrysenyl group, pyrenyl group, indenyl group, azulenyl group, pyrrolyl group, pyridyl group, furanyl group, thiophenyl group and the like are exemplified. As the aryl group, a phenyl group or a 2-naphthyl group is preferable.

  Examples of the aromatic compounds include aromatic hydrocarbons and heterocyclic aromatic compounds such as benzene, naphthalene, anthracene, phenanthrene, tetracene, chrysene, pyrene, indene, azulene, pyrrole, pyridine, furan, and thiophene. .

  The substituted aryl group partially overlaps with the example of the cyclic unsaturated hydrocarbon group having 3 to 20 carbon atoms described above, but one or more hydrogen atoms of the aryl group are hydrocarbon groups having 1 to 20 carbon atoms, Examples include groups substituted with at least one substituent selected from the group consisting of aryl groups, silicon-containing groups, nitrogen-containing groups, oxygen-containing groups, halogen atoms, and halogen-containing groups. Specifically, 3-methyl Phenyl group (m-tolyl group), 4-methylphenyl group (p-tolyl group), 3-ethylphenyl group, 4-ethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, biphenylyl Group, 4- (trimethylsilyl) phenyl group, 4-aminophenyl group, 4- (dimethylamino) phenyl group, 4- (diethylamino) phenyl group, 4-morpholinyl group Nyl group, 4-methoxyphenyl group, 4-ethoxyphenyl group, 4-phenoxyphenyl group, 3,4-dimethoxyphenyl group, 3,5-dimethoxyphenyl group, 3-methyl-4-methoxyphenyl group, 3,5 -Dimethyl-4-methoxyphenyl group, 3- (trifluoromethyl) phenyl group, 4- (trifluoromethyl) phenyl group, 3-chlorophenyl group, 4-chlorophenyl group, 3-fluorophenyl group, 4-fluorophenyl group , 5-methylnaphthyl group, 2- (6-methyl) pyridyl group and the like.

  In the bridged metallocene compound (a) represented by the above formula [I], n is preferably 1. Such a bridged metallocene compound (hereinafter also referred to as “bridged metallocene compound (a-1)”) is represented by the following general formula [II].

In the formula [II], Y, M, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , Q and j are defined as described above.
The bridged metallocene compound (a-1) has a simplified production process and reduced production costs as compared with the compound in which n in the above formula [I] is an integer of 2 to 4, and this bridged metallocene compound (a- By using 1), the advantage that the production cost of the ethylene-α-olefin copolymer (C) is reduced can be obtained.

In the bridged metallocene compound (a-1) represented by the above formula [II], R ¹ , R ² , R ³ and R ⁴ are preferably all hydrogen. Such a bridged metallocene compound (hereinafter also referred to as “bridged metallocene compound (a-2)”) is represented by the following general formula [III].

In the formula [III], the definitions of Y, M, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , Q and j are as described above. It is as follows.
The bridged metallocene compound (a-2) is a production process compared to a compound in which any one or more of R ¹ , R ² , R ³ and R ^{4 in} the above formula [I] is substituted with a substituent other than a hydrogen atom. Is simplified, the production cost is reduced, and by using this bridged metallocene compound (a-2), the production cost of the ethylene-α-olefin copolymer (C) is reduced. In addition, it is known that the randomness of the ethylene-α-olefin copolymer (C) is generally lowered by performing high temperature polymerization, but the olefin polymerization catalyst containing the crosslinked metallocene compound (a-2) When ethylene and one or more monomers selected from α-olefins having 3 to 20 carbon atoms are copolymerized in the presence, the resulting ethylene-α-olefin copolymer (C), even for high-temperature polymerization The advantage of high randomness is also obtained.

In the bridged metallocene compound (a-2) represented by the above formula [III], any one of R ¹³ and R ¹⁴ is preferably an aryl group or a substituted aryl group. Such a bridged metallocene compound (a-3) has an ethylene-α-olefin copolymer (C) produced as compared with the case where both R ¹³ and R ¹⁴ are substituents other than aryl groups and substituted aryl groups. The advantage that the amount of double bonds is small is obtained.

In the bridged metallocene compound (a-3), one of R ¹³ and R ^14, an aryl group or a substituted aryl group, more preferably the other is an alkyl group having 1 to 20 carbon atoms, R ¹³ and It is particularly preferred that any one of R ¹⁴ is an aryl group or a substituted aryl group, and the other is a methyl group. Such a bridged metallocene compound (hereinafter also referred to as “bridged metallocene compound (a-4)”) is produced in comparison with the case where both R ¹³ and R ¹⁴ are aryl groups or substituted aryl groups. Advantages that the balance between the amount of double bonds in the olefin copolymer (C) and the polymerization activity is excellent, and that the production cost of the ethylene-α-olefin copolymer (C) is reduced by using this crosslinked metallocene compound. Is obtained.

  In the case where the polymerization is carried out under certain conditions of the total pressure and temperature in the polymerization vessel, the increase in the hydrogen partial pressure due to the introduction of hydrogen causes a decrease in the partial pressure of the olefin as a polymerization monomer. Causes a problem of lowering the polymerization rate. Since the polymerization reactor has a limited total internal pressure that is allowed in its design, particularly when excessive hydrogen introduction is required when producing a low molecular weight olefin polymer, the olefin partial pressure is significantly reduced. Polymerization activity may decrease. However, in the case of producing the ethylene-α-olefin copolymer (C) in the present invention using the bridged metallocene compound (a-4), compared with the case where the bridged metallocene compound (a-3) is used, a polymerization reactor. The amount of hydrogen introduced into the catalyst is reduced, the polymerization activity is improved, and the production cost of the ethylene-α-olefin copolymer (C) is reduced.

In the bridged metallocene compound (a-4), R ⁶ and R ¹¹ may be bonded to adjacent substituents to form a ring, and the alkyl group having 1 to 20 carbon atoms and 1 to 20 carbon atoms An alkylene group is preferred. In such a bridged metallocene compound (hereinafter also referred to as “bridged metallocene compound (a-5)”), R ⁶ and R ¹¹ are substitutions other than alkyl groups having 1 to 20 carbon atoms and alkylene groups having 1 to 20 carbon atoms. Compared with a compound substituted with a group, the production process is simplified, the production cost is reduced, and by using this bridged metallocene compound (a-5), the production cost of the ethylene-α-olefin copolymer (C) is reduced. The advantage that is reduced is obtained.

  Bridged metallocene compound (a) represented by the above general formula [I], bridged metallocene compound (a-1) represented by the above general formula [II], bridged metallocene compound represented by the above general formula [III] ( In a-2) and the bridged metallocene compounds (a-3), (a-4), and (a-5), M is more preferably a zirconium atom. When copolymerizing ethylene and one or more monomers selected from α-olefins having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst containing the above-mentioned bridged metallocene compound in which M is a zirconium atom, M is a titanium atom or Compared with the case of a hafnium atom, the polymerization activity is high, and there are obtained advantages that the production cost of the ethylene-α-olefin copolymer (C) is reduced.

As such a bridged metallocene compound (a),
[Dimethylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -fluorenyl)] zirconium dichloride, [Dimethylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylfluorenyl) Zirconium dichloride, [dimethylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -3,6-di-t-butylfluorenyl)] zirconium dichloride, [dimethylmethylene (η ⁵ -cyclopentadienyl) (Η ⁵ -octamethyloctahydrodibenzofluorenyl)] zirconium dichloride, [dimethylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -tetramethyloctahydrodibenzofluorenyl)] zirconium dichloride,
[Cyclohexylidene (η ⁵ -cyclopentadienyl) (η ⁵ -fluorenyl)] zirconium dichloride, [Cyclohexylidene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylful) Oreniru)] zirconium dichloride, [cyclohexylidene (eta ⁵ - cyclopentadienyl) (eta ^5-3,6-di -t- butyl-fluorenyl)] zirconium dichloride, [cyclohexylidene (eta ⁵ - cyclo Pentadienyl) (η ⁵ -octamethyloctahydrodibenzofluorenyl)] zirconium dichloride, [cyclohexylidene (η ⁵ -cyclopentadienyl) (η ⁵ -tetramethyloctahydrodibenzofluorenyl)] zirconium dichloride ,
[Diphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -fluorenyl)] zirconium dichloride, [Diphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylfluorenyl) )] Zirconium dichloride, diphenylmethylene (η ⁵ -2-methyl-4-t-butylcyclopentadienyl) (η ⁵ -2,7-di-t-butylfluorenyl)] zirconium dichloride, [diphenylmethylene ( η ⁵ -cyclopentadienyl) (η ⁵ -3,6-di-t-butylfluorenyl)] zirconium dichloride, [diphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -octamethyloctahydrodibenzo Fluorenyl)] zirconium dichloride, diphenylmethylene {η ^5- (2-methyl-4-i-propylcyclo) Pentadienyl)} (η ⁵ -octamethyloctahydrodibenzofluorenyl)] zirconium dichloride, [diphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -tetramethyloctahydrodibenzofluorenyl)] zirconium dichloride,
[Methylphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -fluorenyl)] zirconium dichloride, [Methylphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylful) Oreniru)] zirconium dichloride, [methylphenylmethylene (eta ⁵ - cyclopentadienyl) (eta ^5-3,6-di -t- butyl-fluorenyl)] zirconium dichloride, [methylphenylmethylene (eta ⁵ - cyclo Pentadienyl) (η ⁵ -octamethyloctahydrodibenzofluorenyl)] zirconium dichloride, [methylphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -tetramethyloctahydrodibenzofluorenyl)] zirconium dichloride ,
[Methyl (3-methylphenyl) methylene (η ⁵ -cyclopentadienyl) (η ⁵ -fluorenyl)] zirconium dichloride, [Methyl (3-methylphenyl) methylene (η ⁵ -cyclopentadienyl) (η ^5- 2,7-di-t-butylfluorenyl)] zirconium dichloride, [methyl (3-methylphenyl) methylene (η ⁵ -cyclopentadienyl) (η ⁵ -3,6-di-t-butylfluorene) Nyl)] zirconium dichloride, [methyl (3-methylphenyl) methylene (η ⁵ -cyclopentadienyl) (η ⁵ -octamethyloctahydrodibenzofluorenyl)] zirconium dichloride, [methyl (3-methylphenyl) methylene (eta ⁵ - cyclopentadienyl) (eta ⁵ - tetramethyl octahydro-dibenzo fluorenyl)] zirconium Mujikurorido,
[Diphenylsilylene (η ⁵ -cyclopentadienyl) (η ⁵ -fluorenyl)] zirconium dichloride, [Diphenylsilylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylfluorenyl) )] Zirconium dichloride, [diphenylsilylene (η ⁵ -cyclopentadienyl) (η ⁵ -3,6-di-t-butylfluorenyl)] zirconium dichloride, [diphenylsilylene (η ⁵ -cyclopentadienyl) (Η ⁵ -octamethyloctahydrodibenzofluorenyl)] zirconium dichloride, [diphenylsilylene (η ⁵ -cyclopentadienyl) (η ⁵ -tetramethyloctahydrodibenzofluorenyl)] zirconium dichloride,
[Bis (3-methylphenyl) silylene (η ⁵ -cyclopentadienyl) (η ⁵ -fluorenyl)] zirconium dichloride, [bis (3-methylphenyl) silylene (η ⁵ -cyclopentadienyl) (η ^5- 2,7-di-t-butylfluorenyl)] zirconium dichloride, [bis (3-methylphenyl) silylene (η ⁵ -cyclopentadienyl) (η ⁵ -3,6-di-t-butylfluorene) Nyl)] zirconium dichloride, [bis (3-methylphenyl) silylene (η ⁵ -cyclopentadienyl) (η ⁵ -octamethyloctahydrodibenzofluorenyl)] zirconium dichloride, [bis (3-methylphenyl) silylene (eta ⁵ - cyclopentadienyl) (eta ⁵ - tetramethyl octahydro-dibenzo fluorenyl) zirconium dichloride De,
[Dicyclohexylsilylene (η ⁵ -cyclopentadienyl) (η ⁵ -fluorenyl)] zirconium dichloride, [Dicyclohexylsilylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylfluorenyl) )] Zirconium dichloride, [dicyclohexylsilylene (η ⁵ -cyclopentadienyl) (η ⁵ -3,6-di-t-butylfluorenyl)] zirconium dichloride, [dicyclohexylsilylene (η ⁵ -cyclopentadienyl) (Η ⁵ -octamethyloctahydrodibenzofluorenyl)] zirconium dichloride, [dicyclohexylsilylene (η ⁵ -cyclopentadienyl) (η ⁵ -tetramethyloctahydrodibenzofluorenyl)] zirconium dichloride,
[Ethylene (η ⁵ -cyclopentadienyl) (η ⁵ -fluorenyl)] zirconium dichloride, [ethylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylfluorenyl)] Zirconium dichloride, [ethylene (η ⁵ -cyclopentadienyl) (η ⁵ -3,6-di-t-butylfluorenyl)] zirconium dichloride, [ethylene (η ⁵ -cyclopentadienyl) (η ^5- Octamethyloctahydrodibenzofluorenyl)] zirconium dichloride, [ethylene (η ⁵ -cyclopentadienyl) (η ⁵ -tetramethyloctahydrodibenzofluorenyl)] zirconium dichloride, and the like.

Although the compound which replaced the zirconium atom of these compounds with the hafnium atom, the compound which replaced the chloro ligand with the methyl group, etc. are illustrated, bridged metallocene compound (a) is not limited to these illustrations. In addition, η ⁵ -tetramethyloctahydrodibenzofluorenyl which is a constituent part of the exemplified bridged metallocene compound (a) is 4,4,7,7-tetramethyl- (5a, 5b, 11a, 12,12a-η ⁵ ) -1,2,3,4,7,8,9,10-octahydrodibenzo [b, H] fluorenyl group, η ⁵ -octamethyloctahydrodibenzofluorenyl is 1,1,4,4 7,7,10,10-octamethyl- (5a, 5b, 11a, 12,12a-η ⁵ ) -1,2,3,4,7,8,9,10-octahydrodibenzo [b, H] fluorenyl Each group is represented.

<Compound (b)>
The polymerization catalyst used in the present invention reacts with the above-mentioned bridged metallocene compound (a), organometallic compound (b-1), organoaluminum oxy compound (b-2), and bridged metallocene compound (a) to form ions. It contains at least one compound (b) selected from the group consisting of compound (b-3) forming a pair.

As the organometallic compound (b-1), specifically, organometallic compounds of Groups 1 and 2 and Groups 12 and 13 of the following periodic table are used.
(B-1a) formula _{^{R a m Al (OR b)}} n H p X q
(In the formula, R ^a and R ^b may be the same or different from each other and each represent a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, X represents a halogen atom, and m represents 0 <m. ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is a number of 0 ≦ q <3, and m + n + p + q = 3)
An organoaluminum compound represented by

Such compounds include tri-n-alkyl aluminum such as trimethylaluminum, triethylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, triisopropylaluminum, triisobutylaluminum, tri sec-butylaluminum, tri-t-butylaluminum, tri-2-methylbutylaluminum, tri-3-methylhexylaluminum, tri-branched alkylaluminum such as tri-2-ethylhexylaluminum, tricyclohexylaluminum, tricyclooctylaluminum Tricycloalkylaluminum such as triphenylaluminum, triarylaluminum such as tri (4-methylphenyl) aluminum, di Isopropyl aluminum hydride, dialkylaluminum hydride such as diisobutylaluminum hydride, Formula _{(i-C 4 H 9)} x Al y (C 5 H 10) z ( wherein, x, y, z are each a positive number, z ≦ 2x.) Alkenyl aluminum such as isoprenyl aluminum, etc., alkyl aluminum alkoxide such as isobutyl aluminum methoxide, isobutyl aluminum ethoxide, dimethyl aluminum methoxide, diethyl aluminum ethoxide, dialkyl such as dibutyl aluminum butoxide aluminum alkoxide, ethylaluminum sesquichloride ethoxide, alkyl aluminum sesqui alkoxides such as butyl sesquichloride butoxide, general formula ^{_{R a 2.5 Al (OR b)}} 0.5 etc. Alkoxy aluminum aryloxides such as partially alkoxylated alkylaluminum, diethylaluminum phenoxide, diethylaluminum (2,6-di-t-butyl-4-methylphenoxide) having the average composition represented, dimethylaluminum chloride Dialkylaluminum halide such as diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide, diisobutylaluminum chloride, alkylaluminum sesquichloride such as ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide, alkylaluminum such as ethylaluminum dichloride Partially halogenated alkylaluminums such as dihalides, Dialkylaluminum hydrides such as diethylaluminum hydride and dibutylaluminum hydride, alkylaluminum dihydrides such as ethylaluminum dihydride and propylaluminum dihydride, and other partially hydrogenated alkylaluminums, ethylaluminum ethoxychloride, butylaluminum butoxychloride And partially alkoxylated and halogenated alkylaluminum such as ethylaluminum ethoxybromide. A compound similar to the compound represented by the general formula R ^a _m Al (OR ^b ) _n H _p X _q can also be used. For example, organoaluminum in which two or more aluminum compounds are bonded via a nitrogen atom. A compound can be mentioned. Specific examples of such a compound include (C ₂ H ₅ ) ₂ AlN (C ₂ H ₅ ) Al (C ₂ H ₅ ) ₂ .

(B-1b) General formula M ² AlR ^a ₄ (wherein M ² represents Li, Na or K, and R ^a represents a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms). A complex alkylated product of a Group 1 metal of the periodic table and aluminum.

Examples of such compounds include LiAl (C ₂ H ₅ ) ₄ and LiAl (C ₇ H ₁₅ ) ₄ .
(B-1c) General formula R ^a R ^b M ³ (wherein R ^a and R ^b may be the same or different from each other, and represent a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms). , M ³ is Mg, Zn or Cd.) Dialkyl compounds of Group 2 or Group 12 metals of the Periodic Table.

  As the organoaluminum oxy compound (b-2), a conventionally known aluminoxane can be used as it is. Specific examples include compounds represented by the following general formula [IV] and compounds represented by the following general formula [V].

In the formulas [IV] and [V], R represents a hydrocarbon group having 1 to 10 carbon atoms, and n represents an integer of 2 or more.
In particular, methylaluminoxane wherein R is a methyl group and n is 3 or more, preferably 10 or more is used. These aluminoxanes may be mixed with some organoaluminum compounds.

  In the present invention, when copolymerization of ethylene and an α-olefin having 3 or more carbon atoms is carried out at a high temperature, a benzene-insoluble organoaluminum oxy compound exemplified in JP-A-2-78687 is also applied. be able to. Further, organoaluminum oxy compounds described in JP-A-2-167305, aluminoxane having two or more kinds of alkyl groups described in JP-A-2-24701, JP-A-3-103407, and the like are also included. It can be suitably used. The “benzene-insoluble organoaluminum oxy compound” sometimes used in the present invention means that the Al component dissolved in benzene at 60 ° C. is usually 10% or less, preferably 5% or less, particularly preferably in terms of Al atom. It is a compound that is 2% or less and is insoluble or hardly soluble in benzene.

  Examples of the organoaluminum oxy compound (b-2) include modified methylaluminoxane represented by the following general formula [VI].

In formula [VI], R represents a hydrocarbon group having 1 to 10 carbon atoms, and m and n each independently represents an integer of 2 or more.
This modified methylaluminoxane is prepared using trimethylaluminum and an alkylaluminum other than trimethylaluminum. Such a compound is generally called MMAO. Such MMAO can be prepared by the methods listed in US Pat. No. 4,960,878 and US Pat. No. 5,041,584. In addition, those prepared by using trimethylaluminum and triisobutylaluminum from Tosoh Finechem Co., Ltd. and having R as an isobutyl group are commercially available under the names MMAO and TMAO. Such MMAO is an aluminoxane having improved solubility in various solvents and storage stability. Specifically, it is based on benzene among the compounds represented by the above formula [IV] and [V]. Unlike insoluble or hardly soluble compounds, it is soluble in aliphatic hydrocarbons and alicyclic hydrocarbons.

  Furthermore, the organoaluminum oxy compound (b-2) can also include an organoaluminum oxy compound containing boron represented by the following general formula [VII].

In the formula [VII], R ^c represents a hydrocarbon group having 1 to 10 carbon atoms. R ^d may be the same as or different from each other, and represents a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 10 carbon atoms.
As the compound (b-3) (hereinafter sometimes abbreviated as “ionized ionic compound” or simply “ionic compound”) that forms an ion pair by reacting with the bridged metallocene compound (a), Japanese Patent Application Laid-Open No. Hei. 1-501950, JP-A-1-502036, JP-A-3-179905, JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, US Pat. No. 5,321,106. Examples include Lewis acids, ionic compounds, borane compounds, and carborane compounds described in publications. Furthermore, heteropoly compounds and isopoly compounds can also be mentioned.

  The ionized ionic compound preferably used in the present invention is a boron compound represented by the following general formula [VIII].

In the formula [VIII], R ^{e +} includes H ⁺ , carbenium cation, oxonium cation, ammonium cation, phosphonium cation, cycloheptyltrienyl cation, ferrocenium cation having a transition metal, and the like. R ^{f to} R ⁱ may be the same as or different from each other, and are substituents selected from a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, a nitrogen-containing group, an oxygen-containing group, a halogen atom, and a halogen-containing group. Yes, preferably a substituted aryl group.

  Specific examples of the carbenium cation include trisubstituted carbenium cations such as triphenylcarbenium cation, tris (4-methylphenyl) carbenium cation, and tris (3,5-dimethylphenyl) carbenium cation. .

  Specific examples of the ammonium cation include trialkyl-substituted ammonium such as trimethylammonium cation, triethylammonium cation, tri (n-propyl) ammonium cation, triisopropylammonium cation, tri (n-butyl) ammonium cation, and triisobutylammonium cation. N, N-dialkylanilinium cation such as cation, N, N-dimethylanilinium cation, N, N-diethylanilinium cation, N, N-2,4,6-pentamethylanilinium cation, diisopropylammonium cation, And dialkylammonium cations such as dicyclohexylammonium cations.

  Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tris (4-methylphenyl) phosphonium cation, and tris (3,5-dimethylphenyl) phosphonium cation.

R ^{e +} is preferably a carbenium cation or an ammonium cation among the above specific examples, and particularly preferably a triphenylcarbenium cation, an N, N-dimethylanilinium cation, or an N, N-diethylanilinium cation.

  Of the ionized ionic compounds preferably used in the present invention, compounds containing a carbenium cation include triphenylcarbenium tetraphenylborate, triphenylcarbeniumtetrakis (pentafluorophenyl) borate, triphenylcarbeniumtetrakis {3, 5-di- (trifluoromethyl) phenyl} borate, tris (4-methylphenyl) carbenium tetrakis (pentafluorophenyl) borate, tris (3,5-dimethylphenyl) carbenium tetrakis (pentafluorophenyl) borate, etc. It can be illustrated.

  Among the ionized ionic compounds preferably used in the present invention, compounds containing a trialkyl-substituted ammonium cation include triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri (n-butyl) ammonium tetraphenylborate, and trimethylammonium. Tetrakis (4-methylphenyl) borate, trimethylammonium tetrakis (2-methylphenyl) borate, tri (n-butyl) ammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis ( Pentafluorophenyl) borate, tripropylammonium tetrakis (2,4-dimethylpheny ) Borate, tri (n-butyl) ammonium tetrakis (3,5-dimethylphenyl) borate, tri (n-butyl) ammonium tetrakis {4- (trifluoromethyl) phenyl} borate, tri (n-butyl) ammonium tetrakis { 3,5-di (trifluoromethyl) phenyl} borate, tri (n-butyl) ammonium tetrakis (2-methylphenyl) borate, dioctadecylmethylammonium tetraphenylborate, dioctadecylmethylammonium tetrakis (4-methylphenyl) borate Dioctadecylmethylammonium tetrakis (4-methylphenyl) borate, dioctadecylmethylammonium tetrakis (pentafluorophenyl) borate, dioctadecylmethylammonium tetra (2,4-dimethylphenyl) borate, dioctadecylmethylammonium tetrakis (3,5-dimethylphenyl) borate, dioctadecylmethylammonium tetrakis {4- (trifluoromethyl) phenyl} borate, dioctadecylmethylammonium tetrakis {3 , 5-di (trifluoromethyl) phenyl} borate, dioctadecylmethylammonium and the like.

  Among the ionized ionic compounds preferably used in the present invention, N, N-dimethylanilinium tetraphenylborate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) are compounds containing N, N-dialkylanilinium cations. ) Borate, N, N-dimethylanilinium tetrakis {3,5-di (trifluoromethyl) phenyl} borate, N, N-diethylanilinium tetraphenylborate, N, N-diethylanilinium tetrakis (pentafluorophenyl) Borate, N, N-diethylanilinium tetrakis {3,5-di (trifluoromethyl) phenyl} borate, N, N-2,4,6-pentamethylanilinium tetraphenylborate, N, N-2,4 , 6-Pentamethylanilinium And the like can be exemplified tetrakis (pentafluorophenyl) borate.

  Among the ionized ionic compounds preferably used in the present invention, examples of the compound containing a dialkylammonium cation include di-n-propylammonium tetrakis (pentafluorophenyl) borate and dicyclohexylammonium tetraphenylborate.

In addition, ionic compounds exemplified by JP-A-2004-51676 can also be used without limitation.
Said ionic compound (b-3) may be used individually by 1 type, and 2 or more types may be mixed and used for it.

  As the organometallic compound (b-1), trimethylaluminum, triethylaluminum and triisobutylaluminum that are easily available for commercial products are preferable. Of these, triisobutylaluminum that is easy to handle is particularly preferred.

  As the organoaluminum oxy compound (b-2), methylaluminoxane which is easily available for commercial products and MMAO prepared using trimethylaluminum and triisobutylaluminum are preferable. Of these, MMAO having improved solubility in various solvents and storage stability is particularly preferable.

  As the ionic compound (b-3), triphenylcarbenium tetrakis (pentafluorophenyl) borate and N, N-dimethylaniline are easily obtained as a commercial product and greatly contribute to the improvement of polymerization activity. Nium tetrakis (pentafluorophenyl) borate is preferred.

  As the compound (b), since the polymerization activity is greatly improved, a combination of triisobutylaluminum and triphenylcarbenium tetrakis (pentafluorophenyl) borate, and triisobutylaluminum and N, N-dimethylanilinium tetrakis (penta A combination with (fluorophenyl) borate is particularly preferred.

<Carrier (c)>
In this invention, you may use a support | carrier (c) as a structural component of an olefin polymerization catalyst as needed.

  The carrier (c) that may be used in the present invention is an inorganic or organic compound, and is a granular or particulate solid. Among these, as the inorganic compound, porous oxides, inorganic chlorides, clays, clay minerals or ion-exchangeable layered compounds are preferable.

As the porous oxide, specifically, SiO ₂ , Al ₂ O ₃ , MgO, ZrO, TiO ₂ , B ₂ O ₃ , CaO, ZnO, BaO, ThO _{2 and the} like, or a composite or mixture containing them, for example, using natural or synthetic zeolites, SiO ₂ -MgO, etc. _{SiO 2 -Al 2 O 3, SiO} 2 -TiO 2, SiO 2 -V 2 O 5, SiO 2 -Cr 2 O 3, SiO 2 -TiO 2 -MgO can do. Of these, those containing SiO ₂ and / or Al ₂ O ₃ as main components are preferred. Such porous oxides have different properties depending on the type and production method, but the carrier preferably used in the present invention has a particle size of 0.5 to 300 μm, preferably 1.0 to 200 μm, and has a specific surface area. Is in the range of 50 to 1000 m ² / g, preferably 100 to 700 m ² / g, and the pore volume is in the range of 0.3 to 3.0 cm ³ / g. Such a carrier is used after calcining at 100 to 1000 ° C., preferably 150 to 700 ° C., if necessary.

As the inorganic chloride, MgCl ₂ , MgBr ₂ , MnCl ₂ , MnBr ₂ or the like is used. The inorganic chloride may be used as it is or after being pulverized by a ball mill or a vibration mill. Alternatively, an inorganic chloride dissolved in a solvent such as alcohol and then precipitated in a fine particle form by a precipitating agent may be used.

Clay is usually composed mainly of clay minerals. In addition, the ion-exchangeable layered compound is a compound having a crystal structure in which the surfaces to be formed are stacked in parallel with a weak binding force by ionic bonds or the like, and the contained ions can be exchanged. Most clay minerals are ion-exchangeable layered compounds. In addition, these clays, clay minerals, and ion-exchange layered compounds are not limited to natural products, and artificial synthetic products can also be used. Further, as clay, clay mineral or ion-exchangeable layered compound, clay, clay mineral, ionic crystalline compound having a layered crystal structure such as hexagonal fine packing type, antimony type, CdCl ₂ type, CdI ₂ type, etc. It can be illustrated. Examples of such clays and clay minerals include kaolin, bentonite, kibushi clay, gyrome clay, allophane, hysinger gel, pyrophyllite, ummo group, montmorillonite group, vermiculite, ryokdeite group, palygorskite, kaolinite, nacrite, dickite And halloysite, and the ion-exchangeable layered compounds include α-Zr (HAsO ₄ ) ₂ .H ₂ O, α-Zr (HPO ₄ ) ₂ , α-Zr (KPO ₄ ) ₂ .3H ₂ O, α-Ti (HPO ₄ ) ₂ , α-Ti (HAsO ₄ ) ₂ .H ₂ O, α-Sn (HPO ₄ ) ₂ .H ₂ O, γ-Zr (HPO ₄ ) ₂ , γ-Ti (HPO ₄ ) ₂ , and crystalline acid salts of polyvalent metals such as γ-Ti (NH ₄ PO ₄ ) ₂ .H ₂ O. The clay and clay mineral used in the present invention are preferably subjected to chemical treatment. As the chemical treatment, any of a surface treatment that removes impurities adhering to the surface and a treatment that affects the crystal structure of clay can be used. Specific examples of the chemical treatment include acid treatment, alkali treatment, salt treatment, and organic matter treatment.

The ion-exchangeable layered compound may be a layered compound in a state where the layers are expanded by exchanging the exchangeable ions between the layers with another large and bulky ion using the ion-exchangeability. Such bulky ions play a role of supporting pillars to support the layered structure, and are usually called pillars. Further, the introduction of another substance (guest compound) between the layered compounds in this way is called intercalation. Guest compounds include cationic inorganic compounds such as TiCl ₄ and ZrCl ₄ , metal alkoxides such as Ti (OR) ₄ , Zr (OR) ₄ , PO (OR) ₃ , and B (OR) ₃ (R is a hydrocarbon) Group), metal hydroxide ions such as [Al ₁₃ O ₄ (OH) ₂₄ ] ⁷⁺ , [Zr ₄ (OH) ₁₄ ] ²⁺ , and [Fe ₃ O (OCOCH ₃ ) ₆ ] ^+. . These compounds are used alone or in combination of two or more. Further, when intercalating these compounds, hydrolytic polycondensation of metal alkoxides such as Si (OR) ₄ , Al (OR) ₃ , Ge (OR) ₄ (R is a hydrocarbon group, etc.) The obtained polymer, a colloidal inorganic compound such as SiO _2, etc. can also coexist. Examples of the pillar include oxides generated by heat dehydration after intercalation of the metal hydroxide ions between layers.

Of these, preferred are clays or clay minerals, and particularly preferred are montmorillonite, vermiculite, pectolite, teniolite and synthetic mica.
Examples of the organic compound as the carrier (c) include granular or fine particle solids having a particle size in the range of 0.5 to 300 μm. Specifically, a (co) polymer produced mainly from an α-olefin having 2 to 14 carbon atoms such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, vinylcyclohexane, styrene (Co) polymers produced by the main component, and their modified products.

  High-temperature polymerization is possible by a polymerization method using an olefin polymerization catalyst capable of producing a highly random ethylene-α-olefin copolymer (C). That is, by using the olefin polymerization catalyst, it is possible to suppress a decrease in randomness of the ethylene-α-olefin copolymer (C) produced during high temperature polymerization. In the solution polymerization, the viscosity of the polymerization solution containing the produced ethylene-α-olefin copolymer (C) decreases at a high temperature. Therefore, the ethylene-α-olefin copolymer (C ) Can be increased, and as a result, productivity per polymerization vessel is improved. The copolymerization of ethylene and α-olefin in the present invention can be carried out in any of liquid phase polymerization methods such as solution polymerization and suspension polymerization (slurry polymerization) or gas phase polymerization methods. Solution polymerization is particularly preferable from the viewpoint of obtaining the maximum amount of water.

The usage and order of addition of each component of the olefin polymerization catalyst is arbitrarily selected. Moreover, at least 2 or more of each component in a catalyst may be contacted previously.
The bridged metallocene compound (a) (hereinafter also referred to as “component (a)”) is usually 10 ⁻⁹ to 10 ⁻¹ mol, preferably 10 ⁻⁸ to 10 ⁻² mol per liter of reaction volume. Used in quantity.

  The organometallic compound (b-1) (hereinafter also referred to as “component (b-1)”) is a molar ratio of the component (b-1) to the transition metal atom (M) in the component (a) [( b-1) / M] is usually used in an amount of 0.01 to 50,000, preferably 0.05 to 10,000.

  The organoaluminum oxy compound (b-2) (hereinafter also referred to as “component (b-2)”) includes an aluminum atom in component (b-2) and a transition metal atom (M) in component (a). The molar ratio [(b-2) / M] is usually 10 to 5,000, preferably 20 to 2,000.

  The ionic compound (b-3) (hereinafter also referred to as “component (b-3)”) has a molar ratio of the component (b-3) to the transition metal atom (M) in the component (a) [( b-3) / M] is usually used in an amount of 1 to 10,000, preferably 1 to 5,000.

  The polymerization temperature is usually −50 ° C. to 300 ° C., preferably 30 to 250 ° C., more preferably 100 ° C. to 250 ° C., and further preferably 130 ° C. to 200 ° C. In the polymerization temperature range of the above range, as the temperature increases, the solution viscosity at the time of polymerization decreases, and the heat of polymerization is easily removed. The polymerization pressure is usually normal pressure to 10 MPa gauge pressure (MPa-G), preferably normal pressure to 8 MPa-G.

The polymerization reaction can be carried out in any of batch, semi-continuous and continuous methods. Furthermore, it is possible to carry out the polymerization continuously in two or more polymerization vessels having different reaction conditions.
The molecular weight of the copolymer obtained can be adjusted by changing the hydrogen concentration or polymerization temperature in the polymerization system. Furthermore, it can also adjust with the quantity of the component (b) to be used. When hydrogen is added, the amount is suitably about 0.001 to 5,000 NL per 1 kg of the produced copolymer.

  The polymerization solvent used in the liquid phase polymerization method is usually an inert hydrocarbon solvent, preferably a saturated hydrocarbon having a boiling point of 50 ° C. to 200 ° C. under normal pressure. Specific examples of the polymerization solvent include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene, and alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane. Particularly preferred are hexane, heptane, octane, decane, and cyclohexane. The α-olefin itself that is the object of polymerization can also be used as a polymerization solvent. Aromatic hydrocarbons such as benzene, toluene, and xylene, and halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane can also be used as polymerization solvents. However, from the viewpoint of reducing environmental impact and human health. From the viewpoint of minimizing the influence of the above, their use is not preferable.

  The kinematic viscosity at 100 ° C. of the olefin polymer depends on the molecular weight of the polymer. That is, if the molecular weight is high, the viscosity is high, and if the molecular weight is low, the viscosity is low. Therefore, the kinematic viscosity at 100 ° C. is adjusted by adjusting the molecular weight. Moreover, the molecular weight distribution (Mw / Mn) of the polymer obtained can be adjusted by removing the low molecular weight component of the polymer obtained by a conventionally known method such as vacuum distillation. Further, the obtained polymer may be hydrogenated (hereinafter also referred to as hydrogenation) by a conventionally known method. If the double bond of the polymer obtained by hydrogenation is reduced, oxidation stability and heat resistance are improved.

The obtained ethylene-α-olefin copolymer (C) may be used singly or in combination of two or more types having different molecular weights or different monomer compositions.
In addition, the ethylene-α-olefin copolymer (C) may be graft-modified with a functional group, or may be further secondary-modified. Examples of secondary modification include the method described in JP-T-2008-508402 and the like, such as the method described in JP-A-61-126120 and Japanese Patent No. 2593264.

<Lubricating oil composition for internal combustion engine>
The lubricating oil composition for an internal combustion engine according to the present invention contains the lubricating base oil composed of the mineral oil (A) and / or the synthetic oil (B) and the ethylene-α-olefin copolymer (C).

Kinematic viscosity at 100 ° C. for an internal combustion engine lubricating oil composition of the present invention is less than 12.5 mm ² / s or more 26.1 mm ² / s. This value of kinematic viscosity is the value measured by the method described in JIS K2283. When the kinematic viscosity at 100 ° C. of the lubricating oil composition for an internal combustion engine exceeds 26.1 mm ² / s, the stirring resistance of the lubricating oil to each part of the internal combustion engine increases, resulting in poor fuel economy. If the kinematic viscosity at 100 ° C. is excessively smaller than 12.5 mm ² / s, metal contact may occur. Kinematic viscosity at 100 ° C. is preferably less than 13.0 mm ² / s or more 26.1 mm ² / s, more preferably 15.0 mm ² / s or more 26.1 mm less than ² / s, more preferably 16.3 mm ² / S or more and less than 26.1 mm ² / s. High fuel-saving performance can be obtained while maintaining good shear stability in this range.

  Furthermore, the rate of decrease in kinematic viscosity at 100 ° C. after 90 cycles in the Kurt Orbahn shear test using a Bosch injector based on ASTM D6278 of the lubricating oil composition for internal combustion engines of the present invention is usually 0.5%. Is less than. That is, the lubricating oil composition for internal combustion engines of the present invention has extremely high shear stability. If the viscosity reduction rate in this test is less than 0.5%, high-power engines such as large displacement engines for construction machinery and heavy machinery, crosshead diesel engine oil for ships, ordinary automobiles, and motorcycles The present invention can be suitably used for a racing engine in a car or a high rotation type engine such as a large displacement motorcycle such as a large two-wheeled vehicle.

  In the lubricating oil composition for an internal combustion engine of the present invention, the blending ratio of the lubricating base oil composed of the mineral oil (A) and / or the synthetic oil (B) and the ethylene-α-olefin copolymer (C) is as follows: Although it is not particularly limited as long as the required characteristics in the intended application are satisfied, the mass ratio of the lubricating base oil to the ethylene-α-olefin copolymer (C) (of the lubricating base oil) The mass / the mass of the copolymer (C) is 99/1 to 30/70.

  Further, the lubricating oil composition for internal combustion engines of the present invention comprises a cleaning dispersant, a viscosity modifier, an antioxidant, a corrosion inhibitor, an antiwear agent, a friction modifier, a pour point depressant, a rust inhibitor and an antifoaming agent. Etc. may be contained.

The following can be illustrated as an additive used for the lubricating oil composition of this invention, These can be used individually by 1 type or in combination of 2 or more types.
Examples of the cleaning dispersant include metal sulfonates, metal phenates, metal phosphonates, and succinimides. Alkali metal and alkaline earth metal salicylates, phenates and sulfonate detergents are preferred in the lubricating oil composition of the present invention. Specific examples include calcium or magnesium sulfonates; finates; salicylates; succinimides; benzylamines and the like. The cleaning dispersant is used in the range of 0 to 18% by mass with respect to 100% by mass of the lubricating oil composition as necessary.

  In particular, the detergent / dispersant used in the high-power engine for ships has a total base number of 30 to 350 mg KOH / g measured by the method described in ISO 3771, and is 0.000 relative to 100% by mass of the lubricating oil composition. It mix | blends in 5-18 mass%, and it adjusts so that the total base number of a lubricating oil composition may be 20 mgKOH / g or more.

  As the viscosity modifier, a known viscosity modifier such as a methacrylate copolymer having a molecular weight of less than 50,000, liquid polybutene, or bright stock which is mineral oil can be used in combination. A viscosity modifier is used in the range of 0-50 mass% with respect to 100 mass% of lubricating oil compositions as needed.

  Examples of the antioxidant include phenolic and amine based compounds such as 2,6-di-t-butyl-4-methylphenol. An antioxidant is used in the range of 0 to 3 mass% with respect to 100 mass% of the lubricating oil composition as necessary.

  Examples of the corrosion inhibitor include compounds such as benzotriazole, benzimidazole and thiadiazole. The corrosion inhibitor is used in the range of 0 to 3% by mass with respect to 100% by mass of the grease composition as necessary.

  Examples of the antiwear agent include inorganic or organic molybdenum compounds such as molybdenum disulfide, graphite, antimony sulfide, polytetrafluoroethylene, and the like. The antiwear agent is used in the range of 0 to 3% by mass with respect to 100% by mass of the lubricating oil composition as necessary.

  As the friction modifier, an amine compound, an imide compound or a fatty acid having at least one alkyl group or alkenyl group having 6 to 30 carbon atoms, particularly a linear alkyl group or linear alkenyl group having 6 to 30 carbon atoms in the molecule. Examples include esters, fatty acid amides, fatty acid metal salts, and the like.

  Examples of the amine compound include linear or branched, preferably linear aliphatic monoamines having 6 to 30 carbon atoms, linear or branched, preferably linear aliphatic polyamines, or fatty acids thereof. An alkylene oxide adduct of a group amine can be exemplified. Examples of the imide compound include a succinimide having a linear or branched alkyl group or alkenyl group having 6 to 30 carbon atoms and / or a modified compound thereof using carboxylic acid, boric acid, phosphoric acid, sulfuric acid, or the like. . Examples of fatty acid esters include esters of linear or branched, preferably linear, fatty acids having 7 to 31 carbon atoms with aliphatic monohydric alcohols or aliphatic polyhydric alcohols. Examples of fatty acid amides include amides of linear or branched, preferably linear fatty acids having 7 to 31 carbon atoms, and aliphatic monoamines or aliphatic polyamines. Examples of the fatty acid metal salt include an alkaline earth metal salt (magnesium salt, calcium salt, etc.) or zinc salt of a linear or branched, preferably linear fatty acid having 7 to 31 carbon atoms.

A friction modifier is used in the range of 0-5.0 mass% with respect to 100 mass% of lubricating oil compositions as needed.
Various known pour point depressants can be used as the pour point depressant. Specifically, a polymer compound containing an organic acid ester group is used, and a vinyl polymer containing an organic acid ester group is particularly preferably used. Examples of vinyl polymers containing organic acid ester groups include alkyl methacrylate (co) polymers, alkyl acrylate (co) polymers, alkyl fumarate (co) polymers, and alkyl maleate (co). Examples include polymers and alkylated naphthalene.

  Such a pour point depressant has a melting point of −13 ° C. or lower, preferably −15 ° C., more preferably −17 ° C. or lower. The melting point of the pour point depressant is measured using a differential scanning calorimeter (DSC). Specifically, about 5 mg of a sample was packed in an aluminum pan, heated to 200 ° C., held at 200 ° C. for 5 minutes, cooled to −40 ° C. at 10 ° C./min, and held at −40 ° C. for 5 minutes. Thereafter, it is determined from an endothermic curve when the temperature is raised at 10 ° C./min.

  The pour point depressant further has a polystyrene equivalent weight average molecular weight obtained by gel permeation chromatography in the range of 20,000 to 400,000, preferably 30,000 to 300,000, more preferably 40,000. In the range of ~ 200,000.

The pour point depressant is used in the range of 0 to 2% by mass with respect to 100% by mass of the lubricating oil composition as necessary.
Examples of the rust preventive agent include various amine compounds, carboxylic acid metal salts, polyhydric alcohol esters, phosphorus compounds, sulfonates, and the like. A rust preventive is used in the range of 0 to 3% by mass with respect to 100% by mass of the lubricating oil composition as necessary.

  Examples of the antifoaming agent include silicone compounds such as dimethylsiloxane and silica gel dispersion, alcohol compounds and ester compounds. An antifoamer is used in the range of 0-0.2 mass% with respect to 100 mass% of lubricating oil compositions as needed.

In addition to the above additives, a demulsifier, a colorant, an oily agent (oiliness improver), and the like can be used as necessary.
In lubricating oils for internal combustion engines, so-called DI packages, in which various necessary additives are blended for this purpose, and concentrated and dissolved in lubricating oils such as mineral oils or synthetic hydrocarbon oils, are supplied industrially. Such a DI package can also be applied to the lubricating oil composition of the present invention.

<Application>
The lubricating oil composition of the present invention can be suitably used for an internal combustion engine oil having an SAE viscosity standard of 40 or higher, and can obtain high fluidity at 40 ° C. or lower while maintaining good shear stability. High engine such as a large displacement engine such as a marine crosshead type diesel engine oil, a high-powered engine such as a racing vehicle in a normal automobile, a motorcycle, or a large displacement motorcycle such as a large motorcycle It can be suitably used as a fuel-saving engine oil for a rotary engine.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.
[Evaluation method]
In the following examples and comparative examples, the physical properties and the like of the ethylene-α-olefin copolymer and the lubricating oil composition for internal combustion engine oil were measured by the following methods.

<Ethylene content (mol%)>
Using a Fourier transform infrared spectrophotometer FT / IR-610 or FT / IR-6100 manufactured by JASCO Corporation, absorption near 721 cm ⁻¹ based on the rolling vibration of the long chain methylene group and 1155 cm ⁻ based on the skeletal vibration of propylene absorbance ratio of the absorption at about ¹ calculates (D1155cm ^-1 / D721cm ^-1), ethylene content from a calibration curve prepared in advance (created using a standard specimen in ASTM D3900) (weight%) Asked. Next, ethylene content (mol%) was calculated | required according to the following formula using the obtained ethylene content (weight%).

<B value>
o-Dichlorobenzene / benzene-d ₆ (4/1 [vol / vol%]) as a measurement solvent, measurement temperature 120 ° C., spectral width 250 ppm, pulse repetition time 5.5 seconds, and pulse width 4.7 · sec. (45 ^o pulse) measurement conditions (100 MHz, JEOL ECX400P), measurement temperature 120 ° C., spectral width 250 ppm, pulse repetition time 5.5 seconds, and pulse width 5.0 · sec (45 ^o pulse) The ¹³ C-NMR spectrum was measured under the conditions (125 MHz, Bruker Biospin AVANCE III cryo-500), and the B value was calculated based on the following formula [1].

In the formula [1], P _E represents the mole fraction of ethylene component, P 2 _O represents the mole fraction of α-olefin component, and P _OE represents the mole fraction of ethylene-α-olefin chain of all dyad chains. Indicates the rate.

<Molecular weight distribution>
The molecular weight distribution was measured as follows using Tosoh Corporation HLC-8320GPC. As a separation column, TSKgel SuperMultipore HZ-M (4) was used, the column temperature was 40 ° C., tetrahydrofuran (manufactured by Wako Pure Chemical Industries) was used as the mobile phase, the development rate was 0.35 ml / min, and the sample concentration was The amount of sample injection was 20 microliters, and a differential refractometer was used as a detector. As the standard polystyrene, one manufactured by Tosoh Corporation (PStQuick MP-M) was used. According to the procedure of general-purpose calibration, the weight average molecular weight (Mw) and the number average molecular weight (Mn) were calculated as polystyrene molecular weight, and the molecular weight distribution (Mw / Mn) was calculated from these values.

<Unsaturated bond amount>
¹ H- under the measurement conditions with o-dichlorobenzene-d ₄ as the measurement solvent, measurement temperature of 120 ° C., spectrum width of 20 ppm, pulse repetition time of 7.0 seconds, and pulse width of 6.15 μsec (45 ^o pulse). NMR spectrum (400 MHz, JEOL ECX400P) was measured. The chemical shift standard uses a solvent peak (orthodichlorobenzene 7.1 ppm) and is derived from the main peak observed at 0-3 ppm and vinyl, vinylidene, disubstituted olefins and trisubstituted olefins observed at 4-6 ppm. The amount of unsaturated bonds per 1000 carbon atoms (numbers / 1000 C) was calculated from the ratio of the integrated values of the peaks.

<Melting point>
Using Seiko Instruments X-DSC-7000, about 8 mg of ethylene-α-olefin copolymer is placed in an aluminum sample pan that can be easily sealed and placed in the DSC cell. The temperature was raised to 150 ° C. at 10 ° C./min, and then held at 150 ° C. for 5 minutes, then the temperature was lowered at 10 ° C./min, and the DSC cell was cooled to −100 ° C. (temperature lowering process). Next, after holding at 100 ° C. for 5 minutes, the temperature is raised at 10 ° C./min. The temperature at which the enthalpy curve obtained in the temperature raising process shows the maximum value is the melting point (Tm), and the total endothermic amount associated with melting is melted. The amount of heat (ΔH) was used. When no peak was observed or the value of heat of fusion (ΔH) was 1 J / g or less, it was considered that the melting point (Tm) was not observed. The method for obtaining the melting point (Tm) and the heat of fusion (ΔH) was based on JIS K7121.

<Chlorine content>
The ethylene-α-olefin copolymer was put into a sample boat and burned and decomposed at a combustion furnace set temperature of 900 ° C. in an Ar / O ₂ stream using Thermo Fisher Scientific ICS-1600. The generated gas at this time was absorbed into the absorbing solution and quantified by ion chromatography.

<Viscosity characteristics>
The 100 ° C. kinematic viscosity and the viscosity index were measured and calculated by the method described in JIS K2283.

<HTHS viscosity>
HTHS viscosity was measured at 150 ° C. by the method described in ASTM D4683.

<CCS viscosity>
The CCS viscosity was measured at −10 ° C., −15 ° C., −20 ° C., −25 ° C., or −30 ° C. by the method described in ASTM D5293.

<MR viscosity>
The MR viscosity was measured at -15 ° C, -20 ° C, -25 ° C, -30 ° C or -35 ° C by the method described in ASTM D4684.

<Viscosity reduction rate after shear test>
A 90-cycle test was performed in the Kurt Orbahn shear test using a Bosch injector by the method described in ASTM D6278, and the rate of decrease in the 100 ° C. kinematic viscosity due to shear represented by the following formula (shear test viscosity decrease rate) was evaluated. .
Shear test viscosity reduction rate (%) = (100 ° C. kinematic viscosity before shearing−100 ° C. kinematic viscosity after shearing) / 100 ° C. kinematic viscosity before shearing × 100

[Production of ethylene-α-olefin copolymer (C)]
The ethylene-α-olefin copolymer (C) was produced according to the following polymerization example. In addition, about the obtained ethylene-alpha-olefin copolymer (C), hydrogenation operation was implemented by the following method as needed.

<Hydrogenation operation>
To a stainless steel autoclave with an internal volume of 1 L, 100 mL of a hexane solution of 0.5 mass% Pd / alumina catalyst and 500 mL of a 30 mass% hexane solution of an ethylene-α-olefin copolymer were added, and the autoclave was sealed and then purged with nitrogen. It was. Next, the temperature was raised to 140 ° C. with stirring, and the inside of the system was replaced with hydrogen. Then, the pressure was increased to 1.5 MPa with hydrogen, and a hydrogenation reaction was performed for 15 minutes.

<Synthesis of metallocene compounds>
[Synthesis Example 1]
[Methylphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylfluorenyl)] Synthesis of zirconium dichloride (i) Synthesis of 6-methyl-6-phenylfulvene Nitrogen atmosphere Under a 200 mL three-necked flask, 7.3 g (101.6 mmol) of lithium cyclopentadiene and 100 mL of dehydrated tetrahydrofuran were added and stirred. The solution was cooled in an ice bath and 15.0 g (111.8 mmol) of acetophenone was added dropwise. Then, it stirred at room temperature for 20 hours and the obtained solution was quenched with dilute hydrochloric acid aqueous solution. Hexane 100mL was added and the soluble part was extracted, and this organic layer was dried with anhydrous magnesium sulfate after washing | cleaning with water and a saturated salt solution. Thereafter, the solvent was distilled off, and the resulting viscous liquid was separated by column chromatography (hexane) to obtain the desired product (red viscous liquid).

(Ii) Synthesis of methyl (cyclopentadienyl) (2,7-di-t-butylfluorenyl) (phenyl) methane 2,7-di-t-butylfluorene in a 100 mL three-necked flask under a nitrogen atmosphere 01 g (7.20 mmol) and 50 mL of dehydrated t-butyl methyl ether were added. While cooling in an ice bath, 4.60 mL (7.59 mmol) of n-butyllithium / hexane solution (1.65 M) was gradually added, and the mixture was stirred at room temperature for 16 hours. After adding 1.66 g (9.85 mmol) of 6-methyl-6-phenylfulvene, the mixture was stirred for 1 hour with heating under reflux. While cooling with an ice bath, 50 mL of water was gradually added, and the resulting bilayer solution was transferred to a 200 mL separatory funnel. After adding 50 mL of diethyl ether and shaking several times, the aqueous layer was removed, and the organic layer was washed 3 times with 50 mL of water and once with 50 mL of saturated brine. After drying over anhydrous magnesium sulfate for 30 minutes, the solvent was distilled off under reduced pressure. When ultrasonic waves were applied to the solution obtained by adding a small amount of hexane, a solid was precipitated, which was collected and washed with a small amount of hexane. Drying under reduced pressure gave 2.83 g of methyl (cyclopentadienyl) (2,7-di-t-butylfluorenyl) (phenyl) methane as a white solid.

(Iii) Synthesis of [methylphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylfluorenyl)] zirconium dichloride In a nitrogen atmosphere, methyl (cyclopenta) was added to a 100 mL Schlenk tube. Dienyl) (2,7-di-t-butylfluorenyl) (phenyl) methane 1.50 g (3.36 mmol), dehydrated toluene 50 mL, and THF 570 μL (7.03 mmol) were sequentially added. While cooling in an ice bath, 4.20 mL (6.93 mmol) of n-butyllithium / hexane solution (1.65 M) was gradually added, and the mixture was stirred at 45 ° C. for 5 hours. The solvent was distilled off under reduced pressure, and 40 mL of dehydrated diethyl ether was added to give a red solution. While cooling in a methanol / dry ice bath, 728 mg (3.12 mmol) of zirconium tetrachloride was added, and the mixture was stirred for 16 hours while gradually warming to room temperature, whereby a red-orange slurry was obtained. The solid obtained by distilling off the solvent under reduced pressure was brought into a glove box, washed with hexane, and extracted with dichloromethane. After evaporating the solvent under reduced pressure and concentrating, a small amount of hexane was added and the mixture was allowed to stand at −20 ° C. to precipitate a red-orange solid. The solid was washed with a small amount of hexane, and then dried under reduced pressure to obtain [methylphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylfull] as a red-orange solid. Olenyl)] 1.20 g of zirconium dichloride was obtained.

[Synthesis Example 2]
Ethylene (eta ⁵ - cyclopentadienyl) (eta ^5-2,7-di -t- butyl-fluorenyl) Synthesis of zirconium dichloride Ethylene (eta ⁵ - cyclopentadienyl) (η ⁵ -2, 7-di-t-butylfluorenyl)] zirconium dichloride was synthesized by the method described in Japanese Patent No. 4367687.

<Polymerization Example 1>
A glass polymerization vessel having an internal volume of 1 L, which was sufficiently purged with nitrogen, was charged with 250 mL of heptane, the temperature in the system was raised to 50 ° C., then ethylene was 25 L / hr, propylene 75 L / hr, and hydrogen 100 L / hr. The polymer was continuously fed into the polymerization vessel at a flow rate of hr and stirred at a stirring speed of 600 rpm. Next, 0.2 mmol of triisobutylaluminum was charged into the polymerization vessel, and then 0.688 mmol of MMAO and [ethylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylfluorenyl)] Polymerization was started by charging 0.00230 mmol of zirconium dichloride premixed in toluene for 15 minutes or more into a polymerization vessel. Thereafter, continuous supply of ethylene, propylene and hydrogen was continued, and polymerization was carried out at 50 ° C. for 15 minutes. After the polymerization was stopped by adding a small amount of isobutyl alcohol into the system, unreacted monomers were purged. The obtained polymer solution was washed 3 times with 100 mL of 0.2 mol / l hydrochloric acid and then 3 times with 100 mL of distilled water, dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. The obtained polymer was dried overnight under reduced pressure at 80 ° C. to obtain 1.43 g of an ethylene-propylene copolymer. Further, this ethylene-propylene copolymer was subjected to a hydrogenation operation.

The polymer obtained by the above operation has an unsaturated bond content of less than 0.1 / 1000 C, a chlorine content of less than 0.1 ppm, an ethylene content of 48.4 mol%, an Mw of 13,628, and an Mw / Mn of 1 .9, B value was 1.2, 100 ° C. kinematic viscosity was 2,040 mm ² / s, and no melting point (melting peak) was observed.

<Polymerization example 2>
By charging 990 mL of heptane and 45 g of propylene into a 2 L stainless steel autoclave sufficiently purged with nitrogen, raising the temperature in the system to 130 ° C., and then supplying 2.24 MPa of hydrogen and 0.09 MPa of ethylene The total pressure was 3 MPaG. Next, 0.4 mmol of triisobutylaluminum, [methylphenylmethylene (η ⁵ -cyclopentadienyl) (η ⁵ -2,7-di-t-butylfluorenyl)] zirconium dichloride 0.0006 mmol and N, N— Polymerization was initiated by injecting 0.006 mmol of dimethylanilinium tetrakis (pentafluorophenyl) borate with nitrogen and setting the stirring rotation speed to 400 rpm. Thereafter, by continuously supplying only ethylene, the total pressure was kept at 3 MPaG, and polymerization was carried out at 130 ° C. for 5 minutes. After the polymerization was stopped by adding a small amount of ethanol to the system, unreacted ethylene, propylene and hydrogen were purged. The obtained polymer solution was washed 3 times with 1000 mL of 0.2 mol / l hydrochloric acid and then 3 times with 1000 mL of distilled water, dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. The obtained polymer was dried overnight at 80 ° C. under reduced pressure, and further, using a 2-03 type thin film distillation apparatus manufactured by Shinko Pantech, the degree of vacuum was maintained at 400 Pa, a set temperature of 180 ° C., and a flow rate of 3.1 ml. Thin film distillation was performed at / min to obtain 22.2 g of an ethylene-propylene copolymer. Further, this ethylene-propylene copolymer was subjected to a hydrogenation operation.

The polymer obtained by the above operation has an unsaturated bond content of less than 0.1 / 1000 C, a chlorine content of less than 0.1 ppm, an ethylene content of 51.9 mol%, an Mw of 2,680, and an Mw / Mn of 1 .4, B value was 1.2, kinematic viscosity at 100 ° C. was 40 mm ² / s, and no melting point (melting peak) was observed.

<Polymerization Example 3>
Ethylaluminum sesquichloride (Al (C ₂ H ₅ ) _1.5 · Cl _1.5 ) prepared at 96 mmol / L by adding 1 liter of dehydrated and purified hexane to a continuous polymerization reactor with a stirring blade with a capacity of 2 liters sufficiently purged with nitrogen A hexane solution of VO (OC ₂ H ₅ ) Cl ₂ prepared to 16 mmol / l as a catalyst was further fed in an amount of 500 ml / h continuously for 1 hour, and hexane was added in an amount of 500 ml / h. It was continuously fed in an amount of 500 ml / h. On the other hand, from the upper part of the polymerization vessel, the polymerization solution was continuously extracted so that the polymerization solution in the polymerization vessel was always 1 liter. Next, ethylene gas was supplied in an amount of 47 L / h, propylene gas in an amount of 47 L / h, and hydrogen gas in an amount of 20 L / h using a bubbling tube. The copolymerization reaction was carried out at 35 ° C. by circulating a refrigerant through a jacket attached to the outside of the polymerization vessel.

The polymerization solution containing the ethylene-propylene copolymer obtained under the above conditions was washed 3 times with 100 mL of 0.2 mol / l hydrochloric acid, then 3 times with 100 mL of distilled water, dried over magnesium sulfate, and then the solvent was reduced in pressure. Distilled off. The resulting polymer was dried overnight at 130 ° C. under reduced pressure. The ethylene-propylene copolymer obtained had an ethylene content of 54.9 mol%, an Mw of 14,036, an Mw / Mn of 2.0, a B value of 1.2, a 100 ° C. kinematic viscosity of 2,100 mm ² / s. The unsaturated bond amount was 0.1 / 1000 C, the chlorine content was 20 ppm, and no melting point (melting peak) was observed.

[Preparation of lubricating oil composition for internal combustion engine]
Components other than the ethylene-α-olefin copolymer (C) used in the preparation of the following lubricating oil composition are as follows.
Lubricating base oil: The following lubricating base oil was used as the mineral oil (A).
Mineral oil-A: API Group I mineral oil having a kinematic viscosity of 6.8 mm ² / s at 100 ° C., a viscosity index of 97, and a pour point of −12.5 ° C.
Mineral oil-B: API Group I mineral oil having a kinematic viscosity at 100 ° C. of 8.8 mm ² / s, a viscosity index of 101, and a pour point of −12.5 ° C.
Mineral oil-C: API Group I mineral oil having a kinematic viscosity at 100 ° C. of 5.3 mm ² / s, a viscosity index of 106, and a pour point of −12.5 ° C. (Super Oil N-32 manufactured by JX Nippon Mining & Metals)
Mineral oil -D: 100 ° C. kinematic viscosity of 4.2 mm ² / s, viscosity index of 122, API Group III mineral oils pour point is -15 ° C. (SK Lubricants Co. Yubase-4)
Mineral oil-E: API Group III mineral oil having a kinematic viscosity at 100 ° C. of 6.5 mm ² / s, a viscosity index of 131, and a pour point of −12 ° C. (Yubase-6 manufactured by SK Lubricants)
Synthetic oil (B): The following lubricating base oil was used as synthetic oil (B).
Synthetic oil-A: Synthetic oil poly-α-olefin having a kinematic viscosity of 100 ° C. of 4.0 mm ² / s, a viscosity index of 123, and a pour point of −60 ° C. or less (NEXBASE 2004 manufactured by Neste)
Synthetic oil-B: Synthetic oil poly-α-olefin having a kinematic viscosity at 100 ° C. of 5.8 mm ² / s, a viscosity index of 138, and a pour point of −60 ° C. or less (NEXBASE 2006 manufactured by Neste)
Synthetic oil-C: fatty acid ester, diisodecyl adipate DI package (DI) manufactured by Daihachi Chemical Co., Ltd. having a kinematic viscosity at 100 ° C. of 3.7 mm ² / s, a viscosity index of 156, and a pour point of −60 ° C. or lower; Infineum Company P-5202
Pour point depressant (PPD): IRGAFLO 720P manufactured by BASF
Bright stock: API Group I mineral oil having a kinematic viscosity of 100 ° C of 29.9 mm ² / s, a viscosity index of 97, and a pour point of -10.0 ° C (Brightstock N460 manufactured by JX Nippon Mining & Metals)

<Lubricating oil composition for internal combustion engine>
[Example 1]
Copolymer (Polymer 1) obtained in Polymerization Example 1 using Mineral Oil-A and Mineral Oil-B, which are mineral oils (A) as the lubricating base oil, as an ethylene-α-olefin copolymer (C). Were mixed with DI package (DI) and pour point depressant (PPD) by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 3 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −20 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 20W-40.

[Example 2]
Mineral oil-A and mineral oil-B, which are mineral oils (A), are used as the lubricating base oil, and polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), And a pour point depressant (PPD) were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 3 shows the amount of each component added and the physical properties of the resulting lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −20 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 20W-50.

[Example 3]
Mineral oil-A and mineral oil-B, which are mineral oils (A), are used as the lubricating base oil, and polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), And a pour point depressant (PPD) were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 3 shows the amount of each component added and the physical properties of the resulting lubricating oil composition. Further, the lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −15 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 25W-60.

[Example 4]
Mineral oil-C, which is a mineral oil (A), is used as the lubricating base oil, and the polymer 1 is used as the ethylene-α-olefin copolymer (C). These, DI package (DI), and pour point depressant (PPD) was mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 3 shows the amount of each component added and the physical properties of the resulting lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −20 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 20W-40.

[Example 5]
Mineral oil-C, which is a mineral oil (A), is used as the lubricating base oil, and the polymer 1 is used as the ethylene-α-olefin copolymer (C). These, DI package (DI), and pour point depressant (PPD) was mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 3 shows the amount of each component added and the physical properties of the resulting lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −20 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 20W-50.

[Example 6]
Mineral oil-C, which is a mineral oil (A), is used as the lubricating base oil, and the polymer 1 is used as the ethylene-α-olefin copolymer (C). These, DI package (DI), and pour point depressant (PPD) was mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 3 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −20 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 20W-60.

[Comparative Example 1]
Mineral oil-A and mineral oil-B, which are mineral oils (A), are used as lubricant base oils, bright stock is used without using ethylene-α-olefin copolymer (C), and these are combined with DI package (DI ) And a pour point depressant (PPD) were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 3 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. Further, the lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −20 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 25W-40.

[Comparative Example 2]
Mineral oil-A and mineral oil-B, which are mineral oils (A), are used as lubricant base oils, bright stock is used without using ethylene-α-olefin copolymer (C), and these are combined with DI package (DI ) And a pour point depressant (PPD) were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 3 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −15 ° C. of less than 60,000 mPa · s, and satisfied SAE engine oil viscosity standard 25W-50.

  When Example 1 that satisfies the SAE viscosity standard 40 is compared with Comparative Example 1, and Example 2 that satisfies the SAE viscosity standard 50 is compared with Comparative Example 2, Example 1 and Example 2 satisfy the SAE viscosity standard 20W. On the other hand, Comparative Example 1 and Comparative Example 2 do not satisfy the CCS viscosity standard of SAE viscosity standard 20W and become SAE viscosity standard 25W. That is, Example 1 has excellent low-temperature fluidity as compared with Comparative Example 1 which is the prior art, and further has a superior viscosity index, so that the fuel saving performance at the time of starting the engine is greatly improved.

  Further, when Example 3 is compared with Comparative Example 2, Example 3 has a low CCS viscosity compared to Comparative Example 2 even though the 100 ° C. kinematic viscosity is high, and can greatly contribute to improvement in fuel consumption of the internal combustion engine. Recognize. Furthermore, the lubricating oils of Examples 4 to 6 have a high viscosity index and an excellent CCS viscosity. In Example 6, the SAE viscosity standard 20W-60 can be realized.

[Example 7]
Mineral oil-D and mineral oil-E, which are mineral oils (A), are used as the lubricating base oil, and polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), And a pour point depressant (PPD) were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. Further, the lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −25 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 15W-40.

[Example 8]
Mineral oil-D and mineral oil-E, which are mineral oils (A), are used as the lubricating base oil, and polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), And a pour point depressant (PPD) were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −25 ° C. of less than 60,000 mPa · s, and satisfied SAE engine oil viscosity standard 15W-50.

[Example 9]
Mineral oil-D and mineral oil-E, which are mineral oils (A), are used as the lubricating base oil, and polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), And a pour point depressant (PPD) were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −20 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 20W-60.

[Example 10]
Synthetic oil-A and synthetic oil-C, which are synthetic oils (B), are used as the lubricating base oil, polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), Were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. Further, the lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −35 ° C. of less than 60,000 mPa · s, and satisfied SAE engine oil viscosity standard 5W-40.

[Example 11]
Synthetic oil-A and synthetic oil-C, which are synthetic oils (B), are used as the lubricating base oil, polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), Were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. Further, the lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −30 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 10W-50.

[Example 12]
Synthetic oil-A and synthetic oil-C, which are synthetic oils (B), are used as the lubricating base oil, polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), Were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −25 ° C. of less than 60,000 mPa · s, and satisfied SAE engine oil viscosity standard 15W-60.

[Example 13]
Synthetic oil-B and synthetic oil-C, which are synthetic oils (B), are used as the lubricating base oil, and polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), Were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −30 ° C. of less than 60,000 mPa · s, and satisfied SAE engine oil viscosity standard 10W-40.

[Example 14]
Synthetic oil-B and synthetic oil-C, which are synthetic oils (B), are used as the lubricating base oil, and polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), Were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −25 ° C. of less than 60,000 mPa · s, and satisfied SAE engine oil viscosity standard 15W-50.

[Example 15]
Synthetic oil-B and synthetic oil-C, which are synthetic oils (B), are used as the lubricating base oil, and polymer 1 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), Were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −20 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 20W-60.

[Example 16]
Synthetic oil-A and synthetic oil-C, which are synthetic oils (B) as lubricating base oils, and a copolymer (polymer 2) obtained in polymerization example 2 as an ethylene-α-olefin copolymer (C) These were mixed with DI package (DI) by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −30 ° C. of less than 60,000 mPa · s, and satisfied SAE engine oil viscosity standard 10W-40.

[Example 17]
Synthetic oil-A and synthetic oil-C, which are synthetic oils (B), are used as the lubricating base oil, and polymer 2 is used as the ethylene-α-olefin copolymer (C), and these, DI package (DI), Were mixed by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −25 ° C. of less than 60,000 mPa · s, and satisfied SAE engine oil viscosity standard 15W-50.

[Example 18]
Copolymer (Polymer 3) obtained in Polymerization Example 3 using Mineral Oil-D and Mineral Oil-E, which are mineral oils (A) as the lubricating base oil, and ethylene-α-olefin copolymer (C). Were mixed with DI package (DI) and pour point depressant (PPD) by a conventional method to prepare a lubricating oil composition for internal combustion engine oil. Table 4 shows the amount of each component added and the physical properties of the obtained lubricating oil composition. The lubricating oil composition had an HTHS viscosity of 3.7 mPa · s or more, an MR viscosity at −20 ° C. of less than 60,000 mPa · s, and satisfied the SAE engine oil viscosity standard 20W-60.

  As shown in Examples 7-18, the lubricating oil composition of the present invention maintains high shear stability and exhibits a very good viscosity index and excellent low temperature fluidity as indicated by CCS viscosity and MR viscosity.

Claims (7)

A lubricating base oil and an ethylene-α-olefin copolymer (C) having the following characteristics (C1) to (C5) are contained, and the kinematic viscosity at 100 ° C. is 12.5 mm ² / s or more and 26. Less than 1 mm ² / s,
The internal combustion engine, wherein the lubricating base oil is composed of a mineral oil (A) having the following characteristics (A1) to (A3) and / or a synthetic oil (B) having the characteristics (B1) to (B3): Lubricating oil composition.
(A1) Kinematic viscosity at 100 ° C. is ² to 10 mm ² / s (A2) Viscosity index is 95 or more (A3) Pour point is −10 ° C. or less (B1) Kinematic viscosity at 100 ° C. is but the range that is 1~10mm ² / s (B2) that a viscosity index of 120 or more (B3) pour point of -30 ° C. or less (C1) an ethylene content of 30 to 85 mol% (C2) Kinematic viscosity at 100 ° C. is 10 to 5,000 mm ² / s (C3) Measured by gel permeation chromatography (GPC) and obtained in terms of polystyrene, molecular weight distribution (Mw / Mn) is 2.5 or less (C4) The following formula [1]

(Wherein P _E represents the mole fraction of ethylene component, P _O represents the mole fraction of α-olefin component, and P _OE represents the mole fraction of ethylene-α-olefin chains of all dyad chains. Show.)
(C5) The amount of unsaturated bonds measured by ¹ H-NMR is less than 0.5 per 1000 carbon atoms.   The lubricating oil composition for an internal combustion engine according to claim 1, wherein the ethylene content of the ethylene-α-olefin copolymer (C) is in the range of 40 to 70 mol%. 3. The lubricating oil composition for an internal combustion engine according to claim 1, wherein the ethylene-α-olefin copolymer (C) has a kinematic viscosity at 100 ° C. of 35 to 2,500 mm ² / s.   The lubricating oil composition for an internal combustion engine according to any one of claims 1 to 3, wherein the α-olefin of the ethylene-α-olefin copolymer (C) is propylene.   The lubricating oil composition for an internal combustion engine according to any one of claims 1 to 4, comprising an ester and a synthetic oil other than the ester as the synthetic oil (B).   A diesel engine oil comprising the lubricating oil composition for an internal combustion engine according to any one of claims 1 to 5.   The lubricating oil composition for internal combustion engines according to any one of claims 1 to 5, having a total base number of at least 20 mg-KOH / g.