JP6326340B2 - Grease composition - Google Patents

Description

  The present invention relates to a grease composition, and more particularly to a grease composition suitable as a grease used for automobile parts and the like.

  Since automobiles (passenger cars) are desired to be smaller and lighter and to expand living spaces, the engine room space has been inevitably reduced. Therefore, various parts installed in the engine room have been further reduced in size and weight. Yes. For electronically controlled motors of automobiles such as electronically controlled throttle bearings, idle rotation control valves (ISCV), exhaust gas recirculation devices (EGR), etc. High temperature due to sealing is a problem. In addition, in order to reduce energy loss at start-up and operability at extremely low temperatures, it is required to have low torque at a low temperature below −20 ° C.

  Grease is used as a lubricant composition used for sliding parts such as gears and bearings. Such greases are also required to have improved durability and improved low-temperature characteristics in response to high temperatures in the usage environment.

  In order to improve the low temperature characteristics of grease, it is common practice to lower the viscosity of the base oil, but lowering the viscosity of the base oil also lowers the viscosity at high temperatures, so oil film formation at high temperatures is reduced. It becomes difficult, and as a result, heat resistance is impaired. In order to achieve both low torque at low temperatures and oil film formation at high temperatures, synthetic oils (poly α-olefins and ethylene-α-olefin copolymers) with excellent temperature-viscosity characteristics are used instead of the conventionally used mineral oils. However, there is still room for examination (Patent Documents 1 to 3).

JP-A-1-308497 JP 2002-249794 A JP 2005-54156 A

  The problem to be solved by the present invention in view of such problems in the prior art is to provide a grease composition having an excellent balance between oil film formation at high temperature and low torque at low temperature. It is what.

  As a result of intensive studies to develop a grease composition having excellent performance, the present inventors have found that a specific ethylene-α-olefin (co) polymer and a thickener are added to a specific lubricating base oil. The present inventors have found that a grease composition containing and satisfying specific conditions can solve the above-mentioned problems, and has completed the present invention. Specifically, the following aspects are mentioned.

[1] 10 to 98% by mass of a lubricating base oil (A) having the following characteristics (A1) to (A3), and an ethylene-α-olefin copolymer having the following characteristics (B1) to (B5) The blend (B) is 89 to 1% by mass, and the thickener (C) is 1 to 30% by mass (the total of the lubricant base oil (A), the copolymer (B) and the thickener (C). The amount of the lubricant base oil (A) and the ethylene-α-olefin copolymer (B) are the same as the lubricant base oil (A) and the ethylene-α-olefin copolymer (B). The grease composition is blended in such a proportion that the mixture thereof has the following characteristics (D1) to (D2).
(A1) Kinematic viscosity at 100 ° C. is 1 to 14 mm ² / s (A2) Viscosity index is 100 or more (A3) Pour point is 0 ° C. or less (B1) Ethylene content is 30 to 30 It is in the range of 85 mol% (B2) Kinematic viscosity at 100 ° C. is 20 to 5,000 mm ² / s (B3) Molecular weight measured by gel permeation chromatography (GPC) and obtained in terms of polystyrene The molecular weight distribution (Mw / Mn) is 2.5 or less (B4)

（式中、Ｐ_Eはエチレン成分の含有モル分率を示し、Ｐ_Oはα−オレフィン成分の含有モル分率を示し、Ｐ_OEは全ｄｙａｄ連鎖のエチレン−α−オレフィン連鎖のモル分率を示す。）
で表されるＢ値が、１．１以上であること
（Ｂ５）¹Ｈ−ＮＭＲにより測定した不飽和結合量が炭素原子１０００個あたり０．５個未満であること
（Ｄ１）１００℃における動粘度が１〜５００ｍｍ²／ｓであること
（Ｄ２）粘度指数が１２０以上であること

(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.)
(B5) The amount of unsaturated bonds measured by ¹ H-NMR is less than 0.5 per 1000 carbon atoms (D1) The viscosity is 1 to 500 mm ² / s (D2) The viscosity index is 120 or more.

[2] The grease composition according to [1], wherein the ethylene-α-olefin copolymer has the following characteristics (B6).
(B6) The weight average molecular weight measured by gel permeation chromatography (GPC) and obtained by polystyrene conversion is 500 to 50,000. [3] The lubricating base oil (A) is further The grease composition according to the above [1] or [2], which has the characteristics of A4) to (A6).
(A4) Kinematic viscosity at 100 ° C. is 1 to 10 mm ² / s (A5) Viscosity index is 105 or more (A6) Pour point is −10 ° C. or less [4] The lubricating base oil Among (A), 30 to 100% by mass is a synthetic oil, and the synthetic oil is a poly-α-olefin (PAO) and / or an ester oil having a viscosity index of 120 or more [1] to [3 ] The grease composition according to any one of the above.

[5] The above [1] to [1] wherein the kinematic viscosity at 40 ° C. of the mixture of the lubricating base oil (A) and the ethylene-α-olefin copolymer (B) is 1 to 10,000 mm ² / s. 4] The grease composition according to any one of [4].
[6] A grease for automobile parts comprising the grease composition according to any one of [1] to [5].

  The grease composition of the present invention is an excellent grease composition with a good balance between oil film formation at high temperatures and low torque at low temperatures compared to conventional grease compositions, and is suitable for use in automotive part greases. it can.

Hereinafter, the grease composition according to the present invention will be described in detail.
The grease composition according to the present invention contains a lubricating base oil (A), an ethylene-α-olefin copolymer (B), and a thickener (C). The olefin copolymer (B) is blended in such a ratio that the kinematic viscosity at 100 ° C. of these mixtures is 1 to 500 mm ² / s and the viscosity index is 120 or more.

<(A) Lubricating base oil>
The lubricating base oil (A) has the following features (A1) to (A3).
(A1) The kinematic viscosity at 100 ° C. is from 1 to 14 mm ² / s. Kinematic viscosity at 100 ° C. of the lubricating base oil (A) is, 1~14mm ² / s, preferably 1 to 10 mm ² / s, more preferably from 2 to 8 mm ² / s. When the kinematic viscosity at 100 ° C. is in this range, the grease composition of the present invention is excellent in terms of balance between volatility and temperature-viscosity characteristics.

(A2) The viscosity index is 100 or more. This viscosity index is measured according to the method described in JIS K2283. The viscosity index of the lubricating base oil (A) is 100 or more, preferably 105 or more, more preferably 110 or more, and still more preferably 120 or more. When the viscosity index is in this range, the grease composition of the present invention has excellent temperature viscosity characteristics.

(A3) The pour point is 0 ° C. or less. The value of the pour point is measured according to the method described in ASTM D97. The pour point of the lubricating base oil (A) is 0 ° C. or lower, preferably −10 ° C. or lower, more preferably −30 ° C. or lower. When the pour point is within this range, the grease composition of the present invention has excellent low-temperature viscosity characteristics.

  Lubricating base oils used in the present invention differ in performance and quality such as viscosity characteristics, heat resistance, oxidation stability, etc. depending on their production methods and refining methods, but are generally roughly classified into mineral oils and synthetic oils. . In addition, API (American Petroleum Institute) classifies lubricating 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 1. The lubricating base oil (A) may be either mineral oil or synthetic oil, and may be any of groups I to V in the API category. Details are described below.

<Mineral oil>
Mineral oils belong to groups I-III in the above-mentioned API category.
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 mineral oil, 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, solvent removal. Examples thereof include those refined by performing one or more treatments such as wax and hydrorefining, and 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.

<Synthetic oil>
Synthetic oils belong to Group IV or Group V in the API category described above.

  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), a grease composition having extremely excellent temperature viscosity characteristics, low temperature viscosity characteristics, and heat resistance can be obtained.

Poly -α- olefins, industrially also available, are commercially available in a 100 ° C. kinematic viscosity 2mm ² / s~100mm ² / s. Among them, it is preferable to use a poly-α-olefin having ^{2 to} 14 mm ² / s because a grease composition having excellent temperature viscosity characteristics can be obtained. 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 (B).
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 (B), 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 (B) and From the viewpoint of compatibility with stabilizers such as an antioxidant having a polar group, a corrosion inhibitor, an antiwear agent, a friction modifier, a pour point depressant, a rust inhibitor and an antifoaming agent which will be described later.

  In the grease composition of the present invention, when a synthetic oil, particularly poly-α-olefin, is used as the lubricating base oil (A), the fatty acid ester is 5 to 20% by mass when the entire grease composition is 100% by mass. It is preferable to contain in the quantity. By containing 5 mass% or more fatty acid ester, favorable compatibility is obtained with respect to a sealing material such as a resin or an elastomer. 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 grease composition, the fatty acid ester is not necessarily required because the mineral oil itself has the effect of suppressing the swelling of the lubricant sealant.

Synthetic oils are preferred because they are superior in heat resistance and temperature-viscosity characteristics compared to mineral oils.
In the grease composition of the present invention, synthetic oil or mineral oil may be used alone as the lubricating base oil (A), or two or more kinds of lubricating oil selected from synthetic oil and mineral oil may be used. An arbitrary mixture of oils and the like may be used.

<(B) Ethylene-α-olefin copolymer>
The ethylene-α-olefin copolymer (B) in the present invention has the following characteristics (B1) to (B5).

(B1) The ethylene content is 30 to 85 mol% The ethylene content of the ethylene-α-olefin copolymer (B) is usually 30 to 85 mol%, preferably 40 to 70 mol%, particularly preferably 45. -65 mol%. When the ethylene content is excessively outside this range, crystallinity is generated at a low temperature, the low temperature viscosity is increased, and the low temperature viscosity characteristic of the grease composition is deteriorated.

The ethylene content of the ethylene-α-olefin copolymer (B) 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.

(B2) The kinematic viscosity at 100 ° C. is 20 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 (B) is 20 to 5,000 mm ² / s, preferably 100 to 4000 mm ² / s, more preferably 200 to 3,000 mm ² / s. Preferably it is 300-1,800 mm < ² > / s. When the kinematic viscosity at 100 ° C. of the ethylene-α-olefin copolymer (B) is excessively lower than the above range, there are many readily volatile components, so that the evaporation loss is increased in the grease composition, and the lubricating base oil ( This is not preferred because the thickening effect on A) and the temperature viscosity characteristics of the grease composition are lowered. Exceeding the above range excessively increases the pour point of the ethylene-α-olefin copolymer, deteriorates the shear stability and heat resistance of the grease composition, and uniformly melts it in the lubricating base oil (A). It becomes difficult.

(B3) Molecular weight distribution is 2.5 or less The molecular weight distribution of the ethylene-α-olefin copolymer (B) 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. The molecular weight distribution exceeding this range means that many low molecular weight components and high molecular weight components are contained. When many low molecular weight components are contained, the readily volatile components increase, and the evaporation loss in the grease composition increases. When the viscosity increases and the thickening effect decreases, and a high molecular weight component is contained in a large amount, the shear stability and heat resistance stability of the grease composition deteriorate. The molecular weight distribution of the ethylene-α-olefin copolymer (B) in the present invention is 1.0 or more, preferably 1.3 or more. When the molecular weight distribution is within this range, the viscosity temperature characteristic and the low temperature viscosity characteristic of the grease composition are excellent.

(B4) B value is 1.1 or more The B value represented by the following formula [1] of the ethylene-α-olefin copolymer (B) is 1.1 or more, preferably 1.2 or more. is there.

式［１］中、Ｐ_Eはエチレン成分の含有モル分率を示し、Ｐ_Oはα−オレフィン成分の含有モル分率を示し、Ｐ_OEは全ｄｙａｄ連鎖のエチレン−α−オレフィン連鎖のモル分率を示す。

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 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. As the B value is larger, the chain structure of ethylene and α-olefin is smaller, the distribution of ethylene and α-olefin is uniform, and the copolymer has a narrow composition distribution. As a result, the larger the B value, the lower the pour point of the ethylene-α-olefin copolymer (B), and the grease composition exhibits better low-temperature viscosity characteristics.

Specific measurement conditions for the B value are as described in the examples.
(B5) 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 (B). 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. More preferably less than 0.3, still more preferably less than 0.2, and particularly preferably less than 0.1. When the unsaturated bond amount is within the range, the heat resistance of the grease composition is improved. Specific measurement conditions for the amount of unsaturated bonds are as described in the examples.

The ethylene-α-olefin copolymer (B) preferably further has at least one characteristic of (B6) and (B7).
(B6) The weight average molecular weight is 500 to 50,000. The weight average molecular weight (Mw) of the ethylene-α-olefin copolymer (B) is measured by gel permeation chromatography (GPC) according to the method described later. Obtained by standard polystyrene conversion. The weight average molecular weight (Mw) is preferably 500 to 50,000, more preferably 1,000 to 30,000, and still more preferably 2,000 to 12,000. When the weight average molecular weight (Mw) of the ethylene-α-olefin copolymer (B) is 500 or more, since there are few readily volatile components, there is little evaporation loss in the grease composition, and the thickening effect and temperature-viscosity characteristics are When the grease composition is excellent and has a viscosity of 50,000 or less, the grease composition has a low pour point, excellent shear stability and heat resistance, and the ethylene-α-olefin copolymer (B) is converted into a lubricating base oil (A). It is easy to melt uniformly.

(B7) No melting point is observed It is preferable that no melting point is observed in the differential scanning calorimetry (DSC) of the ethylene-α-olefin copolymer (B). 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 heat of fusion (ΔH) of the ethylene-α-olefin copolymer (B) were measured by differential scanning calorimetry (DSC), cooled to −100 ° C., and then the heating rate was 10 ° C./min. When the temperature is raised to 150 ° C., the DSC curve is obtained with reference to JIS K7121. If the melting point is not observed, no crystal component is generated at low temperature, so the increase in low-temperature viscosity is suppressed, and the grease composition is excellent in low-temperature viscosity characteristics.

  Examples of the α-olefin used in the ethylene-α-olefin copolymer (B) 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 grease 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 method for producing the ethylene-α-olefin copolymer (B) in the present invention is not particularly limited, but vanadium compounds and organoaluminums as described in Japanese Patent Publication Nos. 2-1163 and 2-9998. And a method using a vanadium catalyst comprising a compound. 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 (B). There is sex.

  On the other hand, in the method using a metallocene catalyst, since chlorine is not substantially left, it is not necessary to consider the possibility of corrosion of metal parts in 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. 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 (B) 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 (B) of the present invention comprises a crosslinked metallocene compound (a) represented by the following general formula [I], an organometallic compound (b-1), an organoaluminum oxy compound (b). -2) and at least one compound (b) selected from the group consisting of the compound (b-3) that reacts with the bridged metallocene compound (a) to form an ion pair, It can be produced by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms.

<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].

式［ＩＩ］において、Ｙ、Ｍ、Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴、Ｒ⁵、Ｒ⁶、Ｒ⁷、Ｒ⁸、Ｒ⁹、Ｒ¹⁰、Ｒ¹¹、Ｒ¹²、Ｒ¹³、Ｒ¹⁴、Ｑおよびｊの定義等は、上述のとおりである。

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 (B) 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].

式［ＩＩＩ］において、Ｙ、Ｍ、Ｒ⁵、Ｒ⁶、Ｒ⁷、Ｒ⁸、Ｒ⁹、Ｒ¹⁰、Ｒ¹¹、Ｒ¹²、Ｒ¹³、Ｒ¹⁴、Ｑおよびｊの定義等は、上述のとおりである。

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 (B) is reduced. In general, it is known that the randomness of the ethylene-α-olefin copolymer (B) is reduced 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 (B) even in 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 (B) produced as compared to 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 (B) and the polymerization activity is excellent, and that the production cost of the ethylene-α-olefin copolymer (B) 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 (B) 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 (B) 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 (B) 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 (B) 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].

式［ＩＶ］および［Ｖ］中、Ｒは炭素数１〜１０の炭化水素基、ｎは２以上の整数を示す。

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].

式［ＶＩ］中、Ｒは炭素数１〜１０の炭化水素基、ｍおよびｎはそれぞれ独立に２以上の整数を示す。

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].

式［ＶＩＩ］中、Ｒ^cは炭素数１〜１０の炭化水素基を示す。Ｒ^dは、互いに同一でも異なっていてもよく、水素原子、ハロゲン原子または炭素数１〜１０の炭化水素基を示す。

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].

式［ＶＩＩＩ］中、Ｒ^e+としては、Ｈ⁺、カルベニウムカチオン、オキソニウムカチオン、アンモニウムカチオン、ホスホニウムカチオン、シクロヘプチルトリエニルカチオン、遷移金属を有するフェロセニウムカチオンなどが挙げられる。Ｒ^f〜Ｒⁱは、互いに同一でも異なっていてもよく、炭素数１〜２０の炭化水素基、ケイ素含有基、窒素含有基、酸素含有基、ハロゲン原子およびハロゲン含有基から選ばれる置換基であり、好ましくは置換アリール基である。

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 or the like, or a composite or mixture containing these, 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 (B). That is, by using the olefin polymerization catalyst, it is possible to suppress a decrease in randomness of the ethylene-α-olefin copolymer (B) generated during high temperature polymerization. In the solution polymerization, the viscosity of the polymerization solution containing the produced ethylene-α-olefin copolymer (B) decreases at a high temperature, so that the ethylene-α-olefin copolymer (B ) 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 (B) may be used alone, or two or more types having different molecular weights or different monomer compositions may be combined.
Moreover, the ethylene-α-olefin copolymer (B) may be graft-modified with functional groups, and these 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.

<(C) Thickener>
As the thickener (C) contained in the grease composition of the present invention, various known thickeners can be used. Specifically, for example, a soap-based thickener represented by lithium soap and composite lithium soap, a urea-based thickener represented by diurea, an inorganic thickener represented by organic clay and silica, polytetra Examples thereof include organic thickeners such as fluoroethylene and melamine cyanurate.

  Examples of the soap-based thickener include sodium soap, lithium soap, calcium soap, aluminum soap, composite sodium soap, composite lithium soap, composite calcium soap, composite aluminum soap, composite barium soap and the like. Of these soaps, lithium soaps having high versatility and excellent balance in heat stability and water resistance are preferable, and lithium 1,2-hydroxystearate is particularly preferable.

  The urea-based thickener can be obtained, for example, by reacting a predetermined diisocyanate with a predetermined monoamine in a base oil. A preferred specific example of the diisocyanate is diphenylmethane-4,4′-diisocyanate. Monoamines include aliphatic amines, aromatic amines, alicyclic amines or mixtures thereof. Specific examples of the aliphatic amine include octylamine, dodecylamine, hexadecylamine, octadecylamine and oleylamine. Specific examples of the aromatic amine include aniline and p-toluidine. Specific examples of alicyclic amines include cyclohexylamine.

<Grease composition>
The grease composition according to the present invention contains the lubricating base oil (A), the ethylene-α-olefin copolymer (B), and a thickener (C).

  The grease composition of the present invention comprises 10 to 98% by mass of the lubricating base oil (A), 89 to 1% by mass of the ethylene-α-olefin copolymer (B), and the thickener (C). Each component is contained in a proportion of 1 to 30% by mass. However, the total of the lubricating base oil (A), the ethylene-α-olefin copolymer (B) and the thickener (C) is 100% by mass. The grease composition according to the present invention is preferably 20 to 90% by mass of the lubricating base oil (A), 79 to 5% by mass of the ethylene-α-olefin copolymer (B), and the thickening agent. 1 to 20% by mass of the agent (C), more preferably 30 to 80% by mass of the lubricating base oil (A), and 68 to 10 mass of the ethylene-α-olefin copolymer (B). %, And the thickener (C) in a proportion of 2 to 10% by mass, more preferably 30 to 60% by mass of the lubricating base oil (A), the ethylene-α-olefin copolymer (B ) In an amount of 60 to 30% by mass, and the thickener (C) in an amount of 2 to 10% by mass.

  When the lubricating base oil (A) is 30 to 100% by mass of a synthetic oil and the synthetic oil is a poly-α-olefin and / or ester oil having a viscosity index of 120 or more, a grease composition It is preferable because the heat resistance and temperature viscosity characteristics of the product are improved. 50-100 mass% is more preferable in it being a synthetic oil, and 80-100 mass% is still more preferable in it being a synthetic oil.

  In the grease composition according to the present invention, the lubricant base oil (A) and the ethylene-α-olefin copolymer (B) are the lubricant base oil (A) and the ethylene-α-olefin copolymer. The mixture with (B) is blended in such a ratio as to have the following characteristics (D1) to (D2).

(D1) The kinematic viscosity at 100 ° C. is 1 to 500 mm ² / s. The kinematic viscosity at 100 ° C. (kinematic viscosity measured according to the method described in JIS K2283) is 1 to 500 mm ² / s, preferably 5 It is -300 mm < ² > / s, Most preferably, it is 20-200 mm < ² > / s. When the kinematic viscosity at 100 ° C. of the mixture of the lubricating base oil (A) and the ethylene-α-olefin copolymer (B) is more than 500 mm ² / s, the low temperature characteristics of the grease composition are reduced, In an automobile having parts using this grease composition, the fuel efficiency is inferior. When the kinematic viscosity at 100 ° C. is excessively below 1 mm ² / s, the oil film of the grease composition cannot be sufficiently maintained at a high temperature.

(D2) The viscosity index is 120 or more The viscosity index (viscosity index measured according to the method described in JIS K2283) is 120 or more, preferably 130 or more, more preferably 140 or more. When the viscosity index is within this range, the grease composition has excellent temperature-viscosity characteristics, and it is possible to achieve both an oil film thickness at high temperature and low-temperature characteristics.

In the grease composition according to the present invention, the lubricating base oil (A) and the ethylene-α-olefin copolymer (B) are the same as the lubricating base oil (A) and the ethylene-α-olefin copolymer. kinematic viscosity at 40 ° C. of the mixture of (B) (kinematic viscosity measured according to the method described in JIS K2283) is preferably 1~10,000mm ² / s, more preferably 1~2,000mm ² / s, More preferably, it is blended at a rate of 1 to 500 mm ² / s. When the kinematic viscosity at 40 ° C. is in the above range, the grease composition has excellent low-temperature characteristics.

  In accordance with the penetration of the grease composition according to the present invention (grease penetration test method (ASTM D217)), the cone attached to the penetration meter was dropped onto the sample at 25 ° C. and allowed to enter over 5 seconds. The degree of penetration calculated from the depth is preferably 200 to 430, more preferably 220 to 385, and still more preferably 265 to 295 (corresponding to NLGI NO. 2). When the penetration is 430 or less, the grease composition is less likely to sag during use and easily maintains lubricity. Since the energy loss at the time of stirring of a grease composition is small as it is 200 or more, the fuel-saving property of the motor vehicle which has the components using a grease composition is excellent. The mixing penetration can be increased or decreased depending on the amount of thickener added, for example.

  The dropping point of the grease composition according to the present invention (according to JIS K2220, when the sample is heated at a heating rate of 1 to 1.5 ° C./min, the temperature when the sample is dropped for the first time) is preferably 150 ° C. As mentioned above, More preferably, it is 180 degreeC or more, More preferably, it is 200 degreeC or more. When the dropping point is within this range, the grease composition does not sag at high temperatures and maintains lubricity. The dropping point can be increased or decreased, for example, by selecting the type of thickener.

  The amount of evaporation of the grease composition in the present invention (according to JIS K2220, the amount of evaporation calculated based on the mass reduced when the sample is heated at 99 ° C. for 22 hours) is preferably 1% or less, more preferably It is 0.5% or less, more preferably 0.3% or less. When the evaporation amount is within this range, the grease composition is excellent in long-term heat resistance. The amount of evaporation can be reduced, for example, by selecting a lubricating base oil having high viscosity and low evaporation loss, and using ethylene-α-olefin having a sufficiently high molecular weight and a narrow molecular weight distribution.

  The oil separation degree of the grease composition in the present invention (the oil separation degree calculated from the mass of oil separated from the sample when the sample is heated at 100 ° C. for 24 hours according to JIS K2220) is preferably 20% or less. More preferably, it is 15% or less, and further preferably 10% or less. When the oil separation degree is within this range, the grease composition is excellent in long-term heat resistance. The degree of oil separation can be increased or decreased, for example, by selecting the type of thickener.

  Low temperature torque at −40 ° C. of the grease composition according to the present invention (a sample is packed in an open bearing specified in JIS B1521, and measured at −40 ° C. in accordance with a grease low temperature torque test method (JIS K2220-18). The starting torque is preferably 500 mN · m or less, more preferably 250 mN · m, still more preferably 150 mN · m, and the rotational torque is preferably 200 mN · m or less, more preferably 120 mN · m or less. More preferably, it is 80 mN · m or less. When the low temperature torque is in this range, the energy loss at the start of a motor or the like using the grease composition is small, and the fuel efficiency of an automobile having this is excellent. This low-temperature torque can be reduced, for example, by reducing the viscosity of the mixture of the lubricating base oil and the ethylene-α-olefin (co) polymer and improving the temperature viscosity index.

  In addition, the grease composition of the present invention comprises an extreme pressure agent, a cleaning dispersant, a viscosity index improver, an antioxidant, a corrosion inhibitor, an antiwear agent, a friction modifier, a pour point depressant, a solid lubricant, and an antirust. Additives such as an agent and an antifoaming agent may be included.

The following can be illustrated as an additive used for the grease composition of this invention, These can be used individually by 1 type or in combination of 2 or more types.
Extreme pressure agent is a generic term for those having the effect of preventing seizure under high loads, and is not particularly limited, but includes sulfides, sulfoxides, sulfones, thiophosphinates, thiocarbonates, sulfurized fats and oils, sulfurized olefins, etc. Examples thereof include sulfur extreme pressure agents; phosphoric acids such as phosphate esters, phosphites, phosphate ester amine salts, and phosphite amines; halogen compounds such as chlorinated hydrocarbons. Two or more of these compounds may be used in combination.

  In addition, by the time the extreme pressure lubrication conditions are reached, hydrocarbons or other organic components constituting the grease composition are carbonized before the extreme pressure lubrication conditions by heating and shearing to form a carbide film on the metal surface. there is a possibility. For this reason, when the extreme pressure agent is used alone, the carbide coating inhibits contact between the extreme pressure agent and the metal surface, and there is a possibility that a sufficient effect of the extreme pressure agent cannot be expected.

  Although the extreme pressure agent may be added alone, the grease composition according to the present invention is mainly composed of a saturated hydrocarbon such as a copolymer, and therefore, together with other additives used in advance, a mineral oil or a synthetic hydrocarbon oil. From the viewpoint of dispersibility, it is preferable to add it in a state dissolved in a lubricating base oil such as the above. Specifically, a grease composition is prepared by selecting a so-called extreme pressure agent package in which various components such as an extreme pressure agent component are blended in advance and further dissolved in a lubricating base oil such as mineral oil or synthetic hydrocarbon oil. The method of adding is more preferable.

  Preferable extreme pressure agents (packages) include LUBRIZOL's Angolamol-98A, LUBRIZOL's Angolamol-6043, Angramol-6085U, AFTON CHEMICAL's HITEC1532, AFTON CHEMICAL's HITEC307, AFTON CHEMICAL's HITECCHE33 Additin RC 9410 and the like.

The extreme pressure agent is used in the range of 0 to 10% 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 mass% with respect to 100 mass% of the grease 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 grease compositions as needed.
Examples of the cleaning dispersant include metal sulfonates, metal phenates, metal phosphonates, and succinimides. The cleaning dispersant is used in the range of 0 to 15% by mass with respect to 100% by mass of the grease composition as necessary.

  Viscosity index improvers include ethylene-α-olefin copolymers (excluding ethylene-α-olefin copolymers (B)), olefin copolymers and methacrylate copolymers having a molecular weight exceeding 50,000. Known viscosity index improvers such as polymers, polyalphaolefins such as decene oligomers, and liquid polybutene can be used in combination. The viscosity index improver is used in the range of 0 to 80% by mass with respect to 100% by mass of the grease composition as necessary.

  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 grease 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 solid lubricant include compounds such as molybdenum disulfide, graphite, and melamine cyanurate, and PTFE. The solid lubricant 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 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 grease composition as necessary.

  Examples of the antifoaming agent include silicone compounds such as dimethylsiloxane and silica gel dispersion, alcohol compounds and ester compounds. An antifoaming agent is used in the range of 0 to 0.2 mass% with respect to 100 mass% of grease 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 grease composition as necessary.
In addition to the above additives, a demulsifier, a colorant, an oily agent (oiliness improver), and the like can be used as necessary.

<Application>
The grease composition of the present invention can be suitably used for various automobile parts, industrial equipment machines and household appliance greases, and is excellent in balance between oil film formation at high temperature and low torque at low temperature. The grease composition of the present invention is extremely useful particularly as a grease for automobile parts.

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 of the ethylene-α-olefin copolymer, the mixture of the lubricating base oil and the ethylene-α-olefin, and the grease composition 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].

式［１］中、Ｐ_Eはエチレン成分の含有モル分率を示し、Ｐ_Oはα−オレフィン成分の含有モル分率を示し、Ｐ_OEは全ｄｙａｄ連鎖のエチレン−α−オレフィン連鎖のモル分率を示す。

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. For the chemical shift standard, the solvent peak (orthodichlorobenzene 7.1 ppm) was used, and from the ratio of the integrated value of the main peak observed at 0-3 ppm and the peak derived from the unsaturated bond observed at 4-6 ppm, The amount of unsaturated bonds per 1000 carbon atoms (numbers / 1000 C) was calculated.

<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 performed 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, 40 ° C. kinematic viscosity, and viscosity index were measured and calculated by the method described in JIS K2283.
The physical properties and the like of the grease composition according to the present invention were measured by the following methods.

<Mixed penetration>
In accordance with the grease consistency test method (ASTM D217), the cone was attached to the penetration meter on the sample at 25 ° C. and calculated from the depth of entry over 5 seconds.

<Drip point>
In accordance with JIS K2220, when the sample was heated at a heating rate of 1 to 1.5 ° C./min, the temperature when the sample was dropped for the first time was taken as the dropping point.

<Evaporation amount>
Based on JIS K2220, the amount of evaporation was calculated based on the change in weight when the sample was heated at 99 ° C. for 22 hours.

<Oil separation degree>
In accordance with JIS K2220, the mass of oil separated from the sample when the sample was heated at 100 ° C. for 24 hours was measured, and the degree of oil separation was calculated.

<Low temperature torque>
Samples are packed in an open type bearing specified by JIS B1521, and the starting torque (mN · m) and rotational torque (-20 ° C or -40 ° C) and rotational torque (in accordance with the grease low temperature torque test method (JIS K2220-18)) mN · m) was measured.

<Oxidation stability>
In accordance with the grease oxidation stability test method (JIS K 2220-12), a sample pressurized to 755 kPa with an oxygen cylinder was heated to 99 ° C., and the pressure drop (kPa) after 100 hours was measured.

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

<Hydrogenation operation>
To a 1 L stainless steel autoclave, 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 after sealing the autoclave, nitrogen substitution was performed. 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>
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 2>
Ethyl aluminum sesquichloride (Al (C ₂ H ₅ ) _1.5 · Cl _1.5 ) adjusted to 96 mmol / L in a continuous polymerization reactor equipped with a stirring blade with a capacity of 2 liters sufficiently purged with nitrogen and filled with 1 liter of dehydrated and purified hexane A hexane solution of VO (OC ₂ H ₅ ) Cl ₂ adjusted to 16 mmol / l as a catalyst was further supplied 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 27 L / h, propylene gas in an amount of 26 L / h, and hydrogen gas in an amount of 100 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 content of the obtained ethylene-propylene copolymer was 53.0 mol%, Mw was 2,743, Mw / Mn was 1.5, B value was 1.2, 100 ° C. kinematic viscosity was 40 mm ² / s, The unsaturated bond amount was 0.1 / 1000 C, the chlorine content was 18 ppm, and no melting point (melting peak) was observed.

<Polymerization Example 3>
By charging 710 mL of heptane and 145 g of propylene into a 2 L stainless steel autoclave sufficiently purged with nitrogen, raising the temperature in the system to 150 ° C., and then supplying hydrogen 0.40 MPa and ethylene 0.27 MPa 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 0.0001 mmol and N, N— Polymerization was initiated by injecting 0.001 mmol of dimethylanilinium tetrakis (pentafluorophenyl) borate with nitrogen and setting the stirring speed to 400 rpm. Thereafter, only ethylene was continuously supplied to keep the total pressure at 3 MPaG, and polymerization was carried out at 150 ° 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 under reduced pressure at 80 ° C. to obtain 52.2 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 53.1 mol%, an Mw of 8,559, and an Mw / Mn of 1 , B value was 1.2, 100 ° C. kinematic viscosity was 608 mm ² / s, and no melting point (melting peak) was observed.

<Polymerization example 4>
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 5>
Ethyl aluminum sesquichloride (Al (C ₂ H ₅ ) _1.5 · Cl _1.5 ) adjusted to 96 mmol / L in a continuous polymerization reactor equipped with a stirring blade with a capacity of 2 liters sufficiently purged with nitrogen and filled with 1 liter of dehydrated and purified hexane A hexane solution of VO (OC ₂ H ₅ ) Cl ₂ adjusted to 16 mmol / l as a catalyst was further supplied 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 grease composition]
Components other than the ethylene-α-olefin copolymer (B) used in the preparation of the following grease composition are as follows.

Lubricating base oil: The following lubricating base oils were used as synthetic oils.
Synthetic oils -A: 100 ° C. kinematic viscosity of 5.8mm ² / s, 40 ℃ kinematic viscosity of 30.4 mm ² / s, viscosity index of 138, pour point of -50 ° C. or less synthetic oils poly -α- olefin (NEXBASE 2006 manufactured by Neste)
Bright Stock: 100 ° C. kinematic viscosity of 19.9mm ² / s, 40 ℃ kinematic viscosity of 229.5mm ² / s, each of the following as the API (American Petroleum Institute) Group I mineral oil thickener the viscosity index 99 The thickener was used.
Lithium soap: lithium 1,2-hydroxystearate polyurea: diphenylmethane-4,4′-diisocyanate (made by Mitsui Chemicals, trade name: Cosmonate M-50) and cyclohexylamine (made by Kanto Denka Kogyo Co., Ltd.) in base oil Was obtained by reacting.
Antioxidant; phenolic antioxidant (Irganox L135 manufactured by BASF)
Polybutene: high molecular weight liquid polybutene having a weight average molecular weight of 8,400 measured by GPC in the same manner as the ethylene-α-olefin copolymer (Nisseki Polybutene HV-1900, PIB manufactured by JX Nippon Mining & Energy).

<Grease composition>
[Example 1]
Synthetic oil-A as the lubricating base oil (A), copolymer (polymer 3) obtained in Polymerization Example 3 as the ethylene-α-olefin copolymer (B), and lithium soap as the thickener (C) And a mixture of these and an antioxidant were mixed at a high temperature so as to be 100% by mass to prepare a grease composition. Each addition amount is as shown in Table 2. Table 2 shows the physical properties of the grease composition.

  Further, the synthetic oil-A as the lubricating base oil (A) and the polymer 3 as the ethylene-α-olefin copolymer (B) are in a mass ratio (44.1: 50.7) shown in Table 2. A mixture was prepared and the kinematic viscosity at 100 ° C. and 40 ° C. and the viscosity index were measured for this mixture. The results are shown in Table 2.

[Example 2]
Polymer 3 was replaced with the copolymer (polymer 4) obtained in Polymerization Example 4 at the addition amount shown in Table 2, and the addition amount of synthetic oil-A was changed as shown in Table 2. A grease composition was blended and prepared in the same manner as in Example 1. Table 2 shows the physical properties of the grease composition.

  Further, a mixture containing synthetic oil-A as the lubricating base oil (A) and polymer 4 as the ethylene-α-olefin copolymer (B) at a mass ratio shown in Table 2 was prepared. The kinematic viscosity at 100 ° C. and 40 ° C., and the viscosity index were measured. The results are shown in Table 2.

[Example 3]
Polymer 3 was replaced with the copolymer (polymer 5) obtained in Polymerization Example 5 at the addition amount shown in Table 2, and the addition amount of synthetic oil-A was changed as shown in Table 2. A grease composition was blended and prepared in the same manner as in Example 1. Table 2 shows the physical properties of the grease composition.

  Further, a mixture containing a synthetic oil-A as a lubricating base oil (A) and a polymer 5 as an ethylene-α-olefin copolymer (B) in a mass ratio shown in Table 2 was prepared. The kinematic viscosity at 100 ° C. and 40 ° C., and the viscosity index were measured. The results are shown in Table 2.

[Comparative Example 1]
Except that the ethylene-α-olefin copolymer (B) was replaced with PIB at the addition amount shown in Table 2 and the addition amount of the synthetic oil-A was changed as shown in Table 2, the same as in Example 1. A grease composition was blended and prepared. Table 2 shows the physical properties of the grease composition.

  Also, a mixture containing synthetic oil-A as a lubricating base oil (A) and PIB at a mass ratio shown in Table 2 was prepared, and kinematic viscosity at 100 ° C. and 40 ° C., and a viscosity index were measured for this mixture. did. The results are shown in Table 2.

[Comparative Example 2]
Without using the lubricating base oil (A), the ethylene-α-olefin copolymer (B) was replaced with the copolymer (polymer 1) obtained in Polymerization Example 1 with the addition amount shown in Table 2. A grease composition was formulated and prepared in the same manner as in Example 1 except that the thickener (C) was replaced with polyurea at the addition amount shown in Table 2. Table 2 shows the physical properties of the grease composition.

  The grease composition of Examples 1 to 3 containing an ethylene-α-olefin copolymer (B), which is a grease using a synthetic oil as a lubricating base oil, is an ethylene-α-olefin copolymer (B). As compared with the grease composition of Comparative Example 1 using high molecular weight liquid polybutene instead, it can be seen that the kinematic viscosity at 100 ° C. is almost equal and the low temperature torque is excellent. This is because the mixture of the lubricant base oil (A) and the ethylene-α-olefin copolymer (B) is a mixture of the lubricant base oil (A) having the same kinematic viscosity at 100 ° C. and the high molecular weight liquid polybutene. This is considered to be due to the low kinematic viscosity at 40 ° C. and the high viscosity index. It can also be seen that the grease compositions of Examples 1 to 3 have less evaporation than the grease composition of Comparative Example 1. Although the grease composition of Comparative Example 2 containing no lubricating base oil has a low kinematic viscosity at 100 ° C. as compared with the grease compositions of Examples 1 to 3, the low temperature torque is high. A low viscosity index is considered to be a cause.

[Example 4]
Synthetic oil-A as the lubricating base oil (A), copolymer (polymer 1) obtained in Polymerization Example 1 as the ethylene-α-olefin copolymer (B), and lithium soap as the thickener (C) And a mixture of these and an antioxidant were mixed at a high temperature so as to be 100% by mass to prepare a grease composition. Each addition amount is as shown in Table 3. Table 3 shows the physical properties of the grease composition.

  Further, a mixture containing synthetic oil-A as the lubricating base oil (A) and polymer 1 as the ethylene-α-olefin copolymer (B) in a mass ratio shown in Table 3 was prepared. The kinematic viscosity at 100 ° C. and 40 ° C., and the viscosity index were measured. The results are shown in Table 3.

[Example 5]
A grease composition was blended and prepared in the same manner as in Example 4 except that the polymer 1 was replaced with the copolymer (polymer 2) obtained in Polymerization Example 2 in the addition amounts shown in Table 3. Table 3 shows the physical properties of the grease composition.

  Further, a mixture containing a synthetic oil-A as the lubricating base oil (A) and a polymer 2 as the ethylene-α-olefin copolymer (B) in a mass ratio shown in Table 3 was prepared. The kinematic viscosity at 100 ° C. and 40 ° C., and the viscosity index were measured. The results are shown in Table 3.

[Example 6]
A grease composition was formulated and prepared in the same manner as in Example 4 except that the addition amounts of Polymer 1, Synthetic Oil-A and Thickener were changed to the addition amounts shown in Table 3. Table 3 shows the physical properties of the grease composition.

  Further, a mixture containing synthetic oil-A as the lubricating base oil (A) and polymer 1 as the ethylene-α-olefin copolymer (B) in a mass ratio shown in Table 3 was prepared. The kinematic viscosity at 100 ° C. and 40 ° C., and the viscosity index were measured. The results are shown in Table 3.

[Example 7]
The grease composition was blended in the same manner as in Example 4 except that the polymer 1 was replaced with the polymer 3 with the addition amount shown in Table 3 and the addition amount of the synthetic oil-A was changed as shown in Table 3. Prepared. Table 3 shows the physical properties of the grease composition.

  Further, a mixture containing synthetic oil-A as the lubricating base oil (A) and polymer 3 as the ethylene-α-olefin copolymer (B) in a mass ratio shown in Table 3 was prepared. The kinematic viscosity at 100 ° C. and 40 ° C., and the viscosity index were measured. The results are shown in Table 3.

[Example 8]
The grease composition was blended in the same manner as in Example 4 except that the polymer 1 was replaced with the polymer 4 at the addition amount shown in Table 3 and the addition amount of the synthetic oil-A was changed as shown in Table 3. Prepared. Table 3 shows the physical properties of the grease composition.

  Further, a mixture containing synthetic oil-A as the lubricating base oil (A) and polymer 4 as the ethylene-α-olefin copolymer (B) in a mass ratio shown in Table 3 was prepared. The kinematic viscosity at 100 ° C. and 40 ° C., and the viscosity index were measured. The results are shown in Table 3.

[Example 9]
The grease composition was blended in the same manner as in Example 4 except that the polymer 1 was replaced with the polymer 5 at the addition amount shown in Table 3 and the addition amount of the synthetic oil-A was changed as shown in Table 3. Prepared. Table 3 shows the physical properties of the grease composition.

  Further, a mixture containing synthetic oil-A as the lubricating base oil (A) and polymer 5 as the ethylene-α-olefin copolymer (B) in a mass ratio shown in Table 3 was prepared. The kinematic viscosity at 100 ° C. and 40 ° C. and the viscosity index were measured. The results are shown in Table 3.

[Comparative Example 3]
Without using the ethylene-α-olefin copolymer (B), synthetic oil-A was replaced with bright stock at the addition amount shown in Table 3, and the addition amount of the thickener was changed as shown in Table 3. Except for this, a grease composition was blended and prepared in the same manner as in Example 4. Table 3 shows the physical properties of the grease composition.

  The grease composition of Example 6 containing an ethylene-α-olefin copolymer (B) as a grease using a synthetic oil as a lubricating base oil, does not use the ethylene-α-olefin copolymer (B). When compared with the grease composition of Comparative Example 3, it can be seen that the low temperature torque is excellent. This is considered to be due to the fact that the mixture of the lubricating base oil (A) and the ethylene-α-olefin copolymer (B) has a higher viscosity index than bright stock having the same 100 ° C. kinematic viscosity. It is done. It can be seen that Examples 4, 5, and 7-9, which contain the ethylene-α-olefin copolymer (B) and have a low 100 ° C. kinematic viscosity, are more excellent in low-temperature torque than Example 6.

Claims (6)

10 to 98% by mass of a lubricating base oil (A) having the following characteristics (A1) to (A3), and an ethylene-α-olefin copolymer having the following characteristics (B1) to (B5) (B ) And 1 to 30% by mass of the thickener (C) (the total amount of the lubricant base oil (A), the copolymer (B) and the thickener (C) is 100). The lubricating base oil (A) and the ethylene-α-olefin copolymer (B) are a mixture of the lubricating base oil (A) and the ethylene-α-olefin copolymer (B). Is a grease composition that is blended in such a proportion that it has the following characteristics (D1) to (D2).
(A1) Kinematic viscosity at 100 ° C. is 1 to 14 mm ² / s (A2) Viscosity index is 100 or more (A3) Pour point is 0 ° C. or less (B1) Ethylene content is 30 to 30 It is in the range of 85 mol% (B2) Kinematic viscosity at 100 ° C. is 20 to 5,000 mm ² / s (B3) Molecular weight measured by gel permeation chromatography (GPC) and obtained in terms of polystyrene The molecular weight distribution (Mw / Mn) is 2.5 or less (B4)

(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.)
(B5) The amount of unsaturated bonds measured by ¹ H-NMR is less than 0.5 per 1000 carbon atoms (D1) The viscosity is 1 to 500 mm ² / s (D2) The viscosity index is 120 or more. The grease composition according to claim 1, wherein the ethylene-α-olefin copolymer has the following characteristics (B6).
(B6) The weight average molecular weight measured by gel permeation chromatography (GPC) and obtained by polystyrene conversion is 500 to 50,000. The grease composition according to claim 1 or 2, wherein the lubricating base oil (A) further has the following characteristics (A4) to (A6).
(A4) The kinematic viscosity at 100 ° C. is 1 to 10 mm ² / s (A5) The viscosity index is 105 or more (A6) The pour point is −10 ° C. or less.   30 to 100% by mass of the lubricating base oil (A) is a synthetic oil, and the synthetic oil is a poly-α-olefin (PAO) and / or an ester oil having a viscosity index of 120 or more. The grease composition according to any one of 1 to 3. 5. The kinematic viscosity at 40 ° C. of the mixture of the lubricating base oil (A) and the ethylene-α-olefin copolymer (B) is 1 to 10,000 mm ² / s. The grease composition according to item.   The grease for motor vehicle parts which consists of a grease composition of any one of Claims 1-5.