Viscosity modifiers for lubricating oils and lubricating oil compositions for working oils

Abstract

This invention provides a viscosity modifier for lubricating oils with excellent temperature viscosity characteristics, namely oil film retention at high temperatures and viscosity characteristics at low temperatures, and excellent operability that maintains performance during long-term use of hydraulic systems; and a lubricating oil composition for machine tools, forming machines, and construction machinery, etc., with excellent energy-saving properties. The viscosity modifier for lubricating oils is formed from (C) ethylene-α-olefin copolymers, wherein the (C) ethylene-α-olefin copolymer has an ethylene molar content in the range of 30-70 mol mol%, a rotational viscosity of 300-8,000 mPa·s at 150°C, a Hassen color of less than 30, a molecular weight distribution (Mw / Mn) of less than 2.5, and a B value of more than 1.1. The lubricating oil composition for working oils contains a lubricating oil base oil formed from (A) mineral oil and / or (B) synthetic oil and the aforementioned viscosity modifier for lubricating oils, wherein the (A) mineral oil has a dynamic viscosity of 10-100 mm at 40°C. 2 / s, viscosity index above 90, pour point below 0℃, and dynamic viscosity of the synthetic oil (B) at 40℃ is 4-100 mm³ / s. 2 The viscosity index is above 90, the pour point is below -30°C, and the dynamic viscosity of the lubricating oil composition for working oil at 40°C is 28–170 mm³ / s. 2 / s.

Description

Technical Field

[0001] This invention relates to viscosity modifiers for lubricating oils and lubricating oil compositions comprising the same. Background Technology

[0002] In industrial equipment and machinery, hydraulic systems that convert the pressurization energy of a hydraulic pump into kinetic energy (working energy) are frequently used in machine tools / forming machines that require high working energy, such as injection molding machines, machine tools, stamping machines, and forging and stamping machines. Hydraulic systems are also widely used in construction machinery such as excavators, wheel loaders, skid steer loaders, and tractors.

[0003] On the other hand, global warming is occurring, and reducing emissions of carbon dioxide, a greenhouse gas, is an urgent priority. Consequently, there is a growing demand for reduced power consumption in hydraulic systems used in various industrial sectors, as described above. To reduce power consumption in hydraulic systems, reducing the viscosity of the lubricating oil to decrease fluid resistance in the hydraulic pump and piping is an effective strategy. Lowering the viscosity from low temperatures to room temperature significantly reduces energy loss during startup. However, the reduced viscosity of the lubricating oil raises concerns about internal leakage at high temperatures or loss of the oil film leading to deterioration of lubricity and frictional losses. Therefore, a lubricating oil with excellent temperature viscosity characteristics—that is, one that does not easily cause fluid loss at low temperatures and has minimal viscosity reduction at high temperatures—is needed (Non-Patent Literature 1).

[0004] To meet these requirements, studies have been conducted on using ethylene-α-olefins, which have excellent temperature viscosity characteristics, as base oils and as working oils as viscosity modifiers (Patent Documents 1 and 2). However, the disclosed compositions all have relatively high viscosity, which is insufficient for energy conservation purposes. Studies have been conducted on using synthetic oils (poly-α-olefins) with sufficiently low viscosity and excellent temperature viscosity characteristics in monomer form, but further research is still needed (Patent Document 3).

[0005] In addition, polymethyl methacrylate and olefin copolymers were also studied as viscosity modifiers, but it was found that there was room for improvement in their operability. That is, they were difficult to weigh when preparing working oil because they were liquid; they were difficult to dissolve in lubricating oil base oil because they were solid; etc. (Patent Documents 4 and 5).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 63-22897

[0009] Patent Document 2: Japanese Patent Application Publication No. 05-70788

[0010] Patent Document 3: Japanese Patent Application Laid-Open No. 2002-519448

[0011] Patent Document 4: Japanese Patent Application Laid-Open No. 2014-157200

[0012] Patent Document 5: Japanese Patent Application Laid-Open No. 2019-521227

[0013] Non-Patent Document

[0014] Non-Patent Document 1: Compiled by the Second Lubrication Technology Section, Lubricants Division, Idemitsu Kosan Co., Ltd., Illustrated Basics of Industrial Lubricating Oil (E to ki Kogyo Yoronyu Kiso no Kiso) (2011), published by Nikkan Kogyo Shimbun Ltd. Summary of the Invention

[0015] Problems to be Solved by the Invention

[0016] In view of the problems in the prior art as described above, the problem to be solved by the present invention is to provide a viscosity modifier that has extremely excellent temperature-viscosity characteristics, namely oil film retention at high temperatures and low-temperature viscosity characteristics, compared with existing lubricating oils containing the same lubricating oil base oil, and can maintain the lubricating oil performance during long-term use, namely a viscosity modifier with excellent shear stability and high operability, and further to provide a lubricating oil composition for working oil that can achieve energy saving by using the same.

[0017] Means for Solving the Problems

[0018] The inventors of the present application conducted in-depth research to develop a viscosity modifier with excellent performance, and as a result, found a specific ethylene-α-olefin (co)polymer. Furthermore, it was found that a lubricating oil composition satisfying specific conditions can solve the above problems, thereby completing the present invention. Specifically, the following embodiments can be cited.

[0019] [1] A viscosity modifier for lubricating oil, which is formed from a (C) ethylene-α-olefin copolymer having the following characteristics (C1) to (C5).

[0020] (C1) The ethylene molar content is in the range of 30 to 70 mol%.

[0021] (C2) The rotational viscosity at 150 °C is 300 to 8,000 mPa·s

[0022] (C3) The Hazen color number is 30 or less

[0023] (C4) In the molecular weight measured by gel permeation chromatography (GPC) and converted to polystyrene, the molecular weight distribution (Mw / Mn) is 2.5 or less

[0024] (C5) The B value represented by the following formula [1] is 1.1 or more

[0025] [Mathematical Expression 1]

[0026]

[0027] (where P is in the formula) E P represents the mole fraction of ethylene. O P represents the molar fraction of α-olefin components. OE This represents the mole fraction of the ethylene-α-olefin chain in the entire binary chain.

[0028] [2] The viscosity modifier for lubricating oil as described in [1] above, wherein the aforementioned (C) ethylene-α-olefin copolymer satisfies the condition that the weight-average molecular weight (Mw) determined by gel permeation chromatography (GPC) and converted to polystyrene is 10,000 to 50,000.

[0029] [3] The viscosity modifier for lubricating oil as described in [1] above, wherein the aforementioned (C) ethylene-α-olefin copolymer satisfies the condition that the weight-average molecular weight (Mw) determined by gel permeation chromatography (GPC) and converted to polystyrene is greater than 12,000 and less than 40,000.

[0030] [4] A working oil lubricating oil composition comprising a lubricating oil base oil and the aforementioned [1] lubricating oil viscosity modifier, wherein the lubricating oil base oil is formed from (A) mineral oil having the characteristics of (A1) to (A3) and / or (B) synthetic oil having the characteristics of (B1) to (B3), and the working oil lubricating oil composition has a dynamic viscosity of 28 to 170 mm at 40°C. 2 / s.

[0031] (A1) The dynamic viscosity at 40℃ is 10–100 mm. 2 / s

[0032] (A2) Viscosity index above 90

[0033] (A3) Pour point below 0°C

[0034] (B1) The dynamic viscosity at 40℃ is 4–100 mm. 2 / s

[0035] (B2) Viscosity index above 90

[0036] (B3) Pour point is below -30℃

[0037] [5] The working oil lubricating oil composition as described in [4] above, wherein the ethylene molar content of the aforementioned (C) ethylene-α-olefin copolymer is in the range of 40 to 60 mol%.

[0038] [6] The working oil lubricating oil composition as described in [4] or [5] above, wherein the rotational viscosity of the aforementioned (C) ethylene-α-olefin copolymer at 150°C is 1,000 to 5,000 mPa·s.

[0039] [7] The working oil lubricating oil composition as described in any one of [4] to [6] above, wherein the α-olefin of the aforementioned (C) ethylene-α-olefin copolymer is propylene.

[0040] [8] A working oil lubricating oil composition as described in any one of [4] to [7] above, wherein the content of the aforementioned (C) ethylene-α-olefin copolymer is 1 to 10% by mass.

[0041] [9] A hydraulic working oil for use in machine tools, forming machines or construction machinery, which is formed from any one of the working oil lubricating oil compositions described in any one of [4] to [8] above.

[0042]

[10] The method for manufacturing the viscosity modifier for lubricating oil described in [1] above includes a step of manufacturing the aforementioned (C) ethylene-α-olefin copolymer using the following method (α).

[0043] Method (α): A method comprising a step of solution polymerization of ethylene with an α-olefin having 3 to 20 carbon atoms in the presence of a catalyst system comprising a bridged metallocene compound (a-1') represented by formula [II-I] and at least one compound (b), wherein the at least one compound (b) is selected from the group consisting of an organometallic compound (b-1), an organoaluminum oxide compound (b-2), and a compound (b-3) that reacts with the aforementioned bridged metallocene compound (a-1') to form an ion pair.

[0044] [Chemical Formula 1]

[0045]

[0046] In formula [II-I], R 1 R 2 R 3 R 4 R 5 R 8 R 9 and R 12 Each group consists independently of a hydrogen atom, a hydrocarbon group with 1 to 20 carbon atoms, or a silicon-containing hydrocarbon group. Multiple adjacent groups can connect with each other to form a ring structure.

[0047] R 6 and R 11 They are the same group, and are hydrocarbon groups with 1 to 20 carbon atoms or silicon-containing hydrocarbon groups.

[0048] R 7 and R 10 They are the same group, and are hydrocarbon groups with 1 to 20 carbon atoms or silicon-containing hydrocarbon groups.

[0049] R 6 R 7 R 10 and R 11 They are not both hydrogen atoms;

[0050] R 6 and R 7 It can bond with hydrocarbons having 2 to 3 carbon atoms to form ring structures.

[0051] R 10 and R 11 It can bond with hydrocarbons having 2 to 3 carbon atoms to form ring structures.

[0052] R 13 and R 14 Each is an aryl group, independent of the others.

[0053] Y represents a carbon atom or a silicon atom;

[0054] M is a titanium atom, a zirconium atom, or a hafnium atom;

[0055] Q can be a halogen atom, a hydrocarbon group with 1 to 20 carbon atoms, an anionic ligand, or a neutral ligand that can coordinate using lone pair electrons.

[0056] j is an integer from 1 to 4.

[0057] Invention Effects

[0058] The viscosity modifier for lubricating oil of the present invention possesses, compared with existing lubricating oils containing the same lubricating oil base oil, extremely superior temperature viscosity characteristics, namely oil film retention at high temperatures and viscosity characteristics at low temperatures, and can maintain the performance of lubricating oil during long-term use. This results in extremely high metering accuracy during lubricating oil manufacturing, and also excellent solubility in the lubricating oil base oil. The lubricating oil composition obtained using this modifier is preferably applied to working oils, especially hydraulic working oils for machine tools, molding machines, or construction machinery. Detailed Implementation

[0059] The viscosity modifier for lubricating oil and the lubricating oil composition for working oil (hereinafter, the lubricating oil composition for working oil is also simply referred to as "lubricating oil composition") of the present invention will be described in detail below.

[0060] [Viscosity modifier for lubricating oils]

[0061] The viscosity modifier for lubricating oil involved in this invention is formed from the following (C) ethylene-α-olefin copolymer.

[0062] <(C) Ethylene-α-olefin copolymer>

[0063] (C) Ethylene-α-olefin copolymers have the following characteristics (C1) to (C5).

[0064] (C1) Ethylene molar content is in the range of 30–70 mol%.

[0065] (C) The ethylene molar content of the ethylene-α-olefin copolymer is typically 30–70 mol%, preferably 40–60 mol%, and particularly preferably 45–58 mol%. If the ethylene molar content deviates from this range, crystallization occurs at low temperatures, the low-temperature viscosity increases, and the low-temperature viscosity characteristics of the lubricating oil composition deteriorate.

[0066] (C) The molar ethylene content of the ethylene-α-olefin copolymer can be determined according to the method described in "Guide to Polymer Analysis" (Asakura Shoten, pp. 163-170). 13 The determination can be performed using C-NMR. Alternatively, the sample calculated using this method can be used as a known sample and determined using Fourier transform infrared spectroscopy (FT-IR).

[0067] (C2) The rotational viscosity at 150℃ is 300–8,000 mPa·s.

[0068] The rotational viscosity value is the value determined using the method described in JIS Z8803. The rotational viscosity of the (C) ethylene-α-olefin copolymer at 150°C is 300–8,000 mPa·s, preferably 800–6,000 mPa·s, more preferably 1,000–5,000 mPa·s, further preferably 1,200–4,500 mPa·s, and particularly preferably 1,500–4,000 mPa·s. If the rotational viscosity of the (C) ethylene-α-olefin copolymer at 150°C is higher than the above range, the shear stability and heat resistance of the lubricating oil composition deteriorate, and it is difficult to melt uniformly in the lubricating oil base oil. If it is lower than the above range, the fluidity of the (C) ethylene-α-olefin copolymer increases during the manufacture of the lubricating oil composition, making stable metering difficult and significantly reducing metering accuracy, and therefore is not preferred.

[0069] (C3) Hassen chromaticity below 30

[0070] The Hassen color value is the value determined using the method described in JIS K0071. The Hassen color value of the (C) ethylene-α-olefin copolymer is 30 or less, preferably 25 or less, and more preferably 20 or less. If the Hassen color value of the (C) ethylene-α-olefin copolymer exceeds this range, it means that there are too many oxygen-containing functional groups in the molecule of the (C) ethylene-α-olefin copolymer, and the heat resistance of the resulting lubricating oil composition deteriorates.

[0071] (C4) Molecular weight distribution is below 2.5

[0072] Regarding the molecular weight distribution of (C) ethylene-α-olefin copolymer, it is determined by gel permeation chromatography (GPC) according to the method described later, and calculated as the ratio (Mw / Mn) of weight-average molecular weight (Mw) obtained by conversion to standard polystyrene. This Mw / Mn is 2.5 or less, preferably 2.3 or less, and more preferably 2.2 or less. A molecular weight distribution exceeding this range refers to the presence of a greater proportion of low-molecular-weight components and high-molecular-weight components. With a greater proportion of low-molecular-weight components, the volatile components increase, the evaporation loss in the lubricating oil composition increases, and the thickening effect decreases. With a greater proportion of high-molecular-weight components, the shear stability and heat resistance of the lubricating oil composition deteriorate.

[0073] (C5) B value is 1.1 or higher.

[0074] (C) The B value of the ethylene-α-olefin copolymer represented by the following formula [1] is 1.1 or more, preferably 1.2 or more.

[0075] [Mathematical Expression 2]

[0076]

[0077] In formula [1], P E P represents the mole fraction of ethylene. O P represents the molar fraction of α-olefin components. OE This represents the mole fraction of the ethylene-α-olefin chain in the entire binary chain.

[0078] The B value is an index representing the randomness of the comonomer chain distribution in the copolymer. For P in the above formula [1], E P O and P OE In other words, it can be measured 13C-NMR spectra were obtained based on reports by J. Cranall [Macromolecules, 15, 353 (1982)], J. Ray [Macromolecules, 10, 773 (1977)], and other known literature such as "Guide to Polymer Analysis" (Asakura Shoten, pp. 163-170). A larger B value indicates fewer chain structures of ethylene and α-olefins, a more uniform distribution of ethylene and α-olefins, and a narrow compositional distribution in the copolymer. Consequently, a larger B value results in a lower pour point for the (C) ethylene-α-olefin copolymer, and the lubricating oil composition exhibits good low-temperature viscosity characteristics. Specific determination conditions for the B value are as described in the examples.

[0079] (C) The ethylene-α-olefin copolymer preferably also has at least one of the features of (C6) and (C7).

[0080] (C6) Weight-average molecular weight is 10,000–50,000

[0081] The weight-average molecular weight (Mw) of the (C) ethylene-α-olefin copolymer is determined by gel permeation chromatography (GPC) according to the method described later, and is obtained by conversion to standard polystyrene. This weight-average molecular weight (Mw) is preferably 12,000 to 40,000, more preferably greater than 12,000 and less than 40,000, further preferably 15,000 to 35,000, and even more preferably 20,000 to 30,000. If the weight-average molecular weight (Mw) of the (C) ethylene-α-olefin copolymer is 10,000 or more, there are fewer volatile components, resulting in less evaporation loss in the lubricating oil composition, and excellent thickening effect and temperature viscosity characteristics. If it is 50,000 or less, the lubricating oil composition has a low pour point, excellent shear stability and heat resistance, and the (C) ethylene-α-olefin copolymer is easily and uniformly melted in the lubricating oil base.

[0082] (C7) Melting point not observed

[0083] For (C) ethylene-α-olefin copolymers, it is preferable that the melting point is not observed in differential scanning calorimetry (DSC). Here, "not observed melting point (Tm)" means that the heat of fusion (ΔH) (unit: J / g) measured by differential scanning calorimetry (DSC) is substantially unmeasurable. "Substantially unmeasurable heat of fusion (ΔH)" means that no peak is observed in the differential scanning calorimeter (DSC) measurement, or the observed heat of fusion is less than 1 J / g. For the melting point (Tm) and heat of fusion (ΔH) of (C) ethylene-α-olefin copolymers, differential scanning calorimetry (DSC) can be performed. The melting point is determined by analyzing the DSC curve with reference to JIS K7121 after cooling to -100°C and then heating to 150°C at a heating rate of 10°C / min. If the melting point is not observed, no crystallizing components will form at low temperatures, thus suppressing the increase in low-temperature viscosity and resulting in excellent low-temperature viscosity characteristics of the lubricating oil composition.

[0084] Examples of α-olefins used in (C) ethylene-α-olefin copolymers include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, and vinylcyclohexane, which are straight-chain or branched α-olefins with 3 to 20 carbon atoms. Preferably, the α-olefin is a straight-chain or branched α-olefin with 3 to 10 carbon atoms; more preferably, propylene, 1-butene, 1-hexene, and 1-octene. From the perspective of the shear stability of the lubricating oil using the obtained copolymer, propylene is the most preferred. These α-olefins can be used alone or in combination of two or more.

[0085] Alternatively, polymerization can be carried out by coexisting at least one other monomer selected from monomers containing polar groups, aromatic vinyl compounds, and cyclic olefins in the reaction system. Other monomers can be used in amounts of, for example, 20 parts by mass or less, preferably 10 parts by mass or less, relative to a total of 100 parts by mass of ethylene and α-olefins having 3 to 20 carbon atoms.

[0086] Examples of monomers containing polar groups include α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, and maleic anhydride, as well as their sodium salts and other metal salts; α,β-unsaturated carboxylic acid esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, methyl methacrylate, and ethyl methacrylate; vinyl esters such as vinyl acetate and vinyl propionate; and glycidyl acrylate and glycidyl methacrylate, etc., which are unsaturated glycidyl groups.

[0087] Examples of aromatic vinyl compounds include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o, p-dimethylstyrene, methoxystyrene, vinyl benzoic acid, methyl vinyl benzoate, vinyl benzyl acetate, hydroxystyrene, p-chlorostyrene, divinylbenzene, α-methylstyrene, allylbenzene, etc.

[0088] Examples of cyclic olefins include cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, and tetracyclododecene, which have 3 to 30 carbon atoms, preferably 3 to 20.

[0089] The method for manufacturing the (C) ethylene-α-olefin copolymer of the present invention is not particularly limited, and methods using vanadium-based catalysts containing vanadium compounds and organoaluminum compounds, as described in Japanese Patent Publication No. 2-1163 and Japanese Patent Publication No. 2-7998, can be cited. Alternatively, as a method for manufacturing copolymers with high polymerization activity, methods using catalyst systems containing metallocene compounds such as zirconium diacene and organoaluminum oxides (aluminoxanes), as described in Japanese Patent Application Publication No. 61-221207, Japanese Patent Publication No. 7-121969, and Japanese Patent No. 2796376, can be employed. This method can reduce the chlorine content of the obtained copolymer and the 2,1-intercalation of propylene, and is therefore more preferred. In the method using a vanadium-based catalyst, more chlorine compounds are used as co-catalysts compared to the method using a metallocene catalyst; therefore, it is possible that trace amounts of chlorine may remain in the obtained (C) ethylene-α-olefin copolymer.

[0090] On the other hand, in methods using metallocene catalysts, virtually no chlorine remains, thus eliminating the possibility of corrosion of metal parts in machinery, etc. 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 using various known methods. Specific determination methods in this invention are as described in the examples.

[0091] Furthermore, the reduction of propylene 2,1-intercalation further reduces the ethylene chain within the copolymer molecule, suppressing intramolecular crystallinity of ethylene. Therefore, it can improve the viscosity-temperature characteristics and low-temperature viscosity characteristics of the lubricating oil composition. The amount of propylene 2,1-intercalation can be determined according to the method described in Japanese Patent Application Publication No. 7-145212. 13 The analytical yield from C-NMR determination is preferably less than 1%, more preferably 0 to 0.5%, and even more preferably 0 to 0.1%. Particularly preferred is that no peak is observed in the range of 15.0 to 17.5 ppm.

[0092] In particular, by utilizing the following method, (C) ethylene-α-olefin copolymers with good performance balance in terms of molecular weight control, molecular weight distribution, amorphousness, and B value can be obtained.

[0093] (C) An ethylene-α-olefin copolymer can be manufactured by copolymerizing ethylene with an α-olefin having 3 to 20 carbon atoms, typically by solution polymerization, in the presence of an olefin polymerization catalyst comprising a bridging metallocene compound (a) represented by the general formula [I] and at least one compound (b), wherein the at least one compound (b) is selected from the group consisting of an organometallic compound (b-1), an organoaluminum oxide compound (b-2), and a compound (b-3) that reacts with the aforementioned bridging metallocene compound (a) to form an ion pair.

[0094] [Chemical Formula 2]

[0095]

[0096] <Bridge-connected metallocene compounds>

[0097] Bridged metallocene compound (a) is represented by the above formula [I]. The following describes the relationship between Y, M, and R in formula [I]. 1 ~R 14 Explain Q, n, and j.

[0098] (Y, M, R) 1 ~R 14 Q, n and j)

[0099] Y is a group 14 atom, for example, carbon atom, silicon atom, germanium atom and tin atom, preferably carbon atom or silicon atom, more preferably carbon atom.

[0100] M is a titanium atom, a zirconium atom, or a hafnium atom, preferably a zirconium atom.

[0101] R 1 ~R 12 The atoms or substituents selected are from the group consisting of hydrogen atoms, hydrocarbon groups with 1 to 20 carbon atoms, silicon-containing groups, nitrogen-containing groups, oxygen-containing groups, halogen atoms, and halogen-containing groups. These atoms or substituents can be the same or different. Additionally, from R... 1 To R 12 Adjacent substituents may bond with each other to form a ring, or they may not bond with each other.

[0102] Among them, R is a preferred method. 6 and R 11 They are the same groups, and are hydrocarbon groups with 1 to 20 carbon atoms or silicon-containing hydrocarbon groups.

[0103] In addition, as another preferred method, R7 and R 10 They are the same groups, and are hydrocarbon groups with 1 to 20 carbon atoms or silicon-containing hydrocarbon groups.

[0104] Alternatively, another preferred method is: R 6 R 7 R 10 and R 11 They are not both hydrogen atoms.

[0105] Furthermore, in one of the preferred embodiments described above, R 6 and R 7 It can bond with hydrocarbons having 2 to 3 carbon atoms to form a ring structure, R 10 and R 11 It can bond with hydrocarbons with 2 to 3 carbon atoms to form a ring structure.

[0106] Here, examples of hydrocarbon groups having 1 to 20 carbon atoms include alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, chain unsaturated hydrocarbon groups having 2 to 20 carbon atoms, 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.

[0107] Examples of alkyl groups with 1 to 20 carbon atoms include methyl, ethyl, n-propyl, allyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl, which are straight-chain saturated hydrocarbon groups; and isopropyl, isobutyl, sec-butyl, tert-butyl, tert-pentyl, neopentyl, 3-methylpentyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-methyl-1-propylbutyl, 1,1-propylbutyl, 1,1-dimethyl-2-methylpropyl, 1-methyl-1-isopropyl-2-methylpropyl, and cyclopropylmethyl, which are branched saturated hydrocarbon groups. The preferred number of carbon atoms for the alkyl group is 1 to 6.

[0108] Examples of cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, norbornenyl, 1-adamantyl, and 2-adamantyl. Examples of groups formed by replacing hydrogen atoms with hydrocarbon groups having 1 to 17 carbon atoms include 3-methylcyclopentyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 4-cyclohexylcyclohexyl, and 4-phenylcyclohexyl. The preferred number of carbon atoms in the cyclic saturated hydrocarbon group is 5 to 11.

[0109] Examples of chain-like unsaturated hydrocarbon groups with 2 to 20 carbon atoms include vinyl groups, 1-propenyl groups, 2-propenyl (allyl) groups, and 1-methylvinyl (isopropenyl) groups as alkenyl groups; and ethynyl groups include ethynyl groups, 1-propynyl groups, and 2-propynyl (propynyl) groups as alkynyl groups. The chain-like unsaturated hydrocarbon group preferably has 2 to 4 carbon atoms.

[0110] Examples of cyclic unsaturated hydrocarbon groups with 3 to 20 carbon atoms include cyclopentadienyl, norbornel, phenyl, naphthyl, indene, azulel, phenanthryl, anthracene, etc.; groups formed by replacing the hydrogen atom of the cyclic unsaturated hydrocarbon group with a hydrocarbon group having 1 to 15 carbon atoms include 3-methylphenyl (m-tolyl), 4-methylphenyl (p-tolyl), 4-ethylphenyl, 4-tert-butylphenyl, 4-cyclohexylphenyl, biphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4,6-trimethylphenyl (trimethylphenyl), etc.; and groups formed by replacing the hydrogen atom of the straight-chain hydrocarbon group or branched saturated hydrocarbon group with a cyclic saturated hydrocarbon group or a cyclic unsaturated hydrocarbon group having 3 to 19 carbon atoms include benzyl, cumyl, etc. The number of carbon atoms in the cyclic unsaturated hydrocarbon group is preferably 6 to 10.

[0111] Examples of alkylene groups with 1 to 20 carbon atoms include methylene, ethylene, dimethylmethylene (isopropylene), ethylmethylene, methyl ethylene, and n-propylene. The preferred number of carbon atoms in an alkylene group is 1 to 6.

[0112] Examples of arylene groups with 6 to 20 carbon atoms include o-phenylene, m-phenylene, p-phenylene, and 4,4'-biphenylene. The preferred number of carbon atoms in the arylene group is 6 to 12.

[0113] Examples of silicon-containing groups include trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, triisopropylsilyl, and other alkylsilyl groups, dimethylphenylsilyl, methyldiphenylsilyl, tert-butyldiphenylsilyl, tert-butyldiphenylsilyl, and other arylsilyl groups, pentamethylsilyl, trimethylsilylmethyl, etc., which are groups in which carbon atoms in a hydrocarbon group with 1 to 20 carbon atoms are replaced by silicon atoms. The alkylsilyl group preferably has 1 to 10 carbon atoms, and the arylsilyl group preferably has 6 to 18 carbon atoms.

[0114] Examples of nitrogen-containing groups include: amino groups; groups formed by replacing the =CH- structural unit of a hydrocarbon group or silicon-containing group having 1 to 20 carbon atoms with a nitrogen atom, groups formed by replacing the -CH2- structural unit with a nitrogen atom bonded to a hydrocarbon group having 1 to 20 carbon atoms, or groups formed by replacing the -CH3 structural unit with a nitrogen atom bonded to a hydrocarbon group having 1 to 20 carbon atoms or a nitrile group, such as dimethylamino, diethylamino, N-morpholino, dimethylaminomethyl, cyano, pyrrolyl, piperidinyl, pyridinyl, etc., and nitro groups. Dimethylamino and N-morpholino are preferred as nitrogen-containing groups.

[0115] Examples of oxygen-containing groups include: hydroxyl; methoxy, ethoxy, tert-butoxy, phenoxy, trimethylsilyloxy, methoxyethoxy, hydroxymethyl, methoxymethyl, ethoxymethyl, tert-butoxymethyl, 1-hydroxyethyl, 1-methoxyethyl, 1-ethoxyethyl, 2-hydroxyethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-oxa-n-butyl, 2-oxa-n-pentyl, 3-oxa-n-pentyl, aldehyde, acetyl, propionyl, benzoyl, trimethylsilylcarbonyl, carbamoyl, methylaminocarbonyl, carboxyl, methoxycarbonyl, carboxymethyl, ethoxycarboxymethyl, carbamoylmethyl, furanyl, pyranyl, etc., which are groups in which the -CH2- structural unit of a hydrocarbon group with 1 to 20 carbon atoms is replaced by an oxygen atom or carbonyl, or the -CH3 structural unit is replaced by an oxygen atom bonded to a hydrocarbon group with 1 to 20 carbon atoms. The preferred oxygen-containing group is methoxy.

[0116] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine, which are elements of Group 17. Examples of halogen-containing groups include trifluoromethyl, tribromomethyl, pentafluoroethyl, and pentafluorophenyl, which are groups formed by replacing hydrogen atoms in hydrocarbon groups, silicon-containing groups, nitrogen-containing groups, or oxygen-containing groups with 1 to 20 carbon atoms, with halogen atoms replacing hydrogen atoms.

[0117] Q is selected from halogen atoms, hydrocarbon groups with 1 to 20 carbon atoms, anionic ligands, and neutral ligands that can coordinate using lone pair electrons, in the same or different combinations.

[0118] 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, it is preferably a chlorine atom. When Q is a hydrocarbon group having 1 to 20 carbon atoms, the number of carbon atoms in the hydrocarbon group is preferably 1 to 7.

[0119] Examples of anionic ligands include alkoxy groups such as methoxy, tert-butoxy, and phenoxy, carboxyl groups such as acetate and benzoate, and sulfonate groups such as methanesulfonate and toluenesulfonate.

[0120] Examples of neutral ligands that can utilize lone pair electrons for coordination include organophosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, and diphenylmethylphosphine, as well as ether compounds such as tetrahydrofuran, diethyl ether, dioxane, and 1,2-dimethoxyethane.

[0121] j is an integer from 1 to 4, preferably 2.

[0122] n is an integer from 1 to 4, preferably 1 or 2, and more preferably 1.

[0123] R 13 and R 14 The atoms or substituents selected are from the group consisting of hydrogen atoms, hydrocarbon groups with 1 to 20 carbon atoms, aryl groups, substituted aryl groups, silicon-containing groups, nitrogen-containing groups, oxygen-containing groups, halogen atoms, and halogen-containing groups. These atoms or substituents can be the same or different. Additionally, R... 13 and R 14 They can bond together to form a ring, or they can remain unbonded. As R... 13 and R 14 One preferred method is that each is an aryl group.

[0124] Details regarding hydrocarbon groups, silicon-containing groups, nitrogen-containing groups, oxygen-containing groups, halogen atoms, and halogen-containing groups with 1 to 20 carbon atoms are as described above.

[0125] As aryl groups, some examples overlap with the aforementioned examples of cyclic unsaturated hydrocarbon groups with 3 to 20 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, anthracene, phenanthryl, and tetraphenyl, which are substituents derived from aromatic compounds. Aryl, pyrene, indole, azulene, pyrrole, pyridyl, furanyl, thiophene, etc. As an aryl group, phenyl or 2-naphthyl is preferred.

[0126] Examples of the aforementioned aromatic compounds include benzene, naphthalene, anthracene, phenanthrene, and tetraphenylene, which are aromatic hydrocarbons and heterocyclic aromatic compounds. Pyrene, indene, azulene, pyrrole, pyridine, furan, thiophene, etc.

[0127] As substituted aryl groups, some of the examples overlap with the aforementioned cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms. Examples include groups formed by substituting one or more hydrogen atoms of the aforementioned aryl group with at least one substituent selected from the group consisting of hydrocarbon groups, aryl groups, silicon-containing groups, nitrogen-containing groups, oxygen-containing groups, halogen atoms, and halogen-containing groups having 1 to 20 carbon atoms. Specifically, examples include 3-methylphenyl (m-tolyl), 4-methylphenyl (p-tolyl), 3-ethylphenyl, 4-ethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, biphenyl, etc. 4-(trimethylsilyl)phenyl, 4-aminophenyl, 4-(dimethylamino)phenyl, 4-(diethylamino)phenyl, 4-morpholinylphenyl, 4-methoxyphenyl, 4-ethoxyphenyl, 4-phenoxyphenyl, 3,4-dimethoxyphenyl, 3,5-dimethoxyphenyl, 3-methyl-4-methoxyphenyl, 3,5-dimethyl-4-methoxyphenyl, 3-(trifluoromethyl)phenyl, 4-(trifluoromethyl)phenyl, 3-chlorophenyl, 4-chlorophenyl, 3-fluorophenyl, 4-fluorophenyl, 5-methylnaphthyl, 2-(6-methyl)pyridyl, etc.

[0128] In the bridged metallocene compound (a) represented by formula [I] above, 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].

[0129] [Chemical Formula 3]

[0130]

[0131] In formula [II], Y, M, R 1 ~R 14 The definitions of Q and j are as described above.

[0132] Compared with compounds in formula [I] where n is an integer from 2 to 4, the manufacturing process of the bridged metallocene compound (a-1) is simplified and the manufacturing cost is reduced. Thus, by using the bridged metallocene compound (a-1), the manufacturing cost of (C) ethylene-α-olefin copolymer can be reduced.

[0133] Among the bridged metallocene compounds (a-1) represented by formula [II] above, a preferred embodiment is a bridged metallocene compound represented by the following definition (this bridged metallocene compound is also referred to as a bridged metallocene compound (a-1'), which corresponds to the compound represented by formula [II]-1 above).

[0134] R 6 and R 11 They are the same groups, and are hydrocarbon groups with 1 to 20 carbon atoms or silicon-containing hydrocarbon groups.

[0135] R 7 and R 10 They are the same groups, and are hydrocarbon groups with 1 to 20 carbon atoms or silicon-containing hydrocarbon groups.

[0136] R 6 R 7 R 10 and R 11 They are not both hydrogen atoms.

[0137] R 6 and R 7 It can bond with hydrocarbons with 2 to 3 carbon atoms to form a ring structure.

[0138] R 10 and R 11 It can bond with hydrocarbons with 2 to 3 carbon atoms to form a ring structure.

[0139] R 13 and R 14 Each is an aryl group, independent of the others.

[0140] Of the bridged metallocene compound (a-1) represented by formula [II] above, R is preferred. 1 R 2 R 3 and R 4 All are hydrogen. Such bridged metallocene compounds (hereinafter also referred to as "bridged metallocene compounds (a-2)") are represented by the following general formula [III].

[0141] [Chemical Formula 4]

[0142]

[0143] In formula [III], Y, M, R 5 ~R 14 The definitions of Q and j are as described above.

[0144] Bridged metallocene compound (a-2) and R in formula [I] above 1 R 2 R 3 and R 4Compared to compounds formed by substituting any one or more of the monomers with substituents other than hydrogen atoms, the manufacturing process is simplified and the manufacturing cost is reduced. Therefore, by using this bridging metallocene compound (a-2), the manufacturing cost of (C) ethylene-α-olefin copolymers can be reduced. Furthermore, although it is known that high-temperature polymerization typically leads to a decrease in the randomness of (C) ethylene-α-olefin copolymers, when ethylene is copolymerized with one or more monomers selected from α-olefins having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst containing this bridging metallocene compound (a-2), the following advantage can be obtained: even with high-temperature polymerization, the resulting (C) ethylene-α-olefin copolymer exhibits high randomness.

[0145] Of the bridged metallocene compound (a-2) represented by formula [III] above, R is preferred. 13 and R 14 Either of them is aryl or substituted aryl. Such bridged metallocene compounds (a-3) with R 13 and R 14 Compared to cases where all substituents are other than aryl and substituted aryl groups, the resulting (C) ethylene-α-olefin copolymer has the advantage of having a lower amount of double bonds.

[0146] In the bridged metallocene compound (a-3), R is further preferred. 13 and R 14 One of them is an aryl or substituted aryl group, and the other is an alkyl group having 1 to 20 carbon atoms, with R being particularly preferred. 13 and R 14 One of them is aryl or substituted aryl, and the other is methyl. Such bridged metallocene compounds (hereinafter also referred to as "bridged metallocene compounds (a-4)") are related to R 13 and R 14 Compared to cases where all groups are aryl or substituted aryl, the resulting (C)ethylene-α-olefin copolymer exhibits a superior balance between the amount of double bonds and the polymerization activity. By using this bridging metallocene compound, the manufacturing cost of the (C)ethylene-α-olefin copolymer can be reduced.

[0147] When polymerization is carried out under constant total pressure and temperature conditions in a polymerizer, the following problems arise: the increase in hydrogen partial pressure due to the introduction of hydrogen causes a decrease in the partial pressure of olefins, which are polymerizable monomers, especially in the region of high hydrogen partial pressure, thus reducing the polymerization rate. The total internal pressure allowed by the polymerizer's design is limited, so especially when producing low molecular weight olefin polymers, if excessive hydrogen is required, the olefin partial pressure decreases significantly, and thus the polymerization activity is sometimes reduced. However, when using the bridged metallocene compound (a-4) to produce the (C) ethylene-α-olefin copolymer of the present invention, compared with the use of the aforementioned bridged metallocene compound (a-3), the following advantages are obtained: the amount of hydrogen introduced into the polymerizer is reduced, the polymerization activity is increased, and the production cost of the (C) ethylene-α-olefin copolymer is reduced.

[0148] In the above-mentioned bridged metallocene compound (a-4), R 6 and R 11 Preferably, the alkyl group having 1 to 20 carbon atoms and the alkylene group having 1 to 20 carbon atoms are capable of bonding with adjacent substituents to form a ring. Such bridged metallocene compounds (hereinafter also referred to as "bridged metallocene compounds (a-5)") are related to R. 6 and R 11 Compared to compounds formed by substituents other than alkyl groups having 1 to 20 carbon atoms and alkylene groups having 1 to 20 carbon atoms, the manufacturing process is simplified and the manufacturing cost is reduced. Thus, by using this bridging metallocene compound (a-5), the manufacturing cost of (C) ethylene-α-olefin copolymer can be reduced.

[0149] In the bridged metallocene compound (a) represented by general formula [I], the bridged metallocene compound (a-1) represented by general formula [II], the bridged metallocene compound (a-2) represented by general formula [III], and the bridged metallocene compounds (a-3), (a-4), and (a-5) mentioned above, M is further preferably a zirconium atom. When ethylene is copolymerized with 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 where M is a zirconium atom, the advantages of high polymerization activity and reduced manufacturing cost of (C) ethylene-α-olefin copolymers can be obtained compared with the case where M is a titanium atom or a hafnium atom.

[0150] As such a bridged metallocene compound (a), [dimethylmethylene (η)] can be cited as an example. 5 -cyclopentadienyl)(η 5 [-fluorene)]zirconium dichloride, [dimethylmethylene(η) 5 -cyclopentadienyl)(η 5-2,7-di-tert-butylfluorene)]zirconium dichloride, [dimethylmethylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorene)]zirconium dichloride, [dimethylmethylene(η 5 -cyclopentadienyl)(η 5 [-octamethyloctahydrodibenzofluorene)]zirconium dichloride, [dimethylmethylene(η 5 -cyclopentadienyl)(η 5 [Tetramethyloctahydrodibenzofluorene]zirconium dichloride, [cyclohexyl(η) 5 -cyclopentadienyl)(η 5 [-fluorene)]zirconium dichloride, [cyclohexyl(η) 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorene)]zirconium dichloride, [cyclohexyl(η) 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorene)]zirconium dichloride, [cyclohexyl(η) 5 -cyclopentadienyl)(η 5 [-octamethyloctahydrodibenzofluorene)]zirconium dichloride, [cyclohexyl(η) 5 -cyclopentadienyl)(η 5 [Tetramethyloctahydrodibenzofluorene]zirconium dichloride, [diphenylmethylene(η) 5 -cyclopentadienyl)(η 5 [-fluorene)]zirconium dichloride, [diphenylmethylene (η) 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorene)]zirconium dichloride, diphenylmethylene (η 5 -2-Methyl-4-tert-butylcyclopentadienyl)(η 5 -2,7-di-tert-butylfluorene)]zirconium dichloride, [diphenylmethylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorene)]zirconium dichloride, [diphenylmethylene(η 5 -cyclopentadienyl)(η 5 [-octamethyloctahydrodibenzofluorene)]zirconium dichloride, [diphenylmethylene{η] 5 -(2-Methyl-4-isopropylcyclopentadienyl)}(η 5 [-octamethyloctahydrodibenzofluorene)]zirconium dichloride, [diphenylmethylene(η) 5 -cyclopentadienyl)(η 5 [Tetramethyloctahydrodibenzofluorene]zirconium dichloride, [methylphenylmethylene (η) 5 -cyclopentadienyl)(η 5[-fluoreneyl)]zirconium dichloride, [methylphenylmethylene(η) 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorene)]zirconium dichloride, [methylphenylmethylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorene)]zirconium dichloride, [methylphenylmethylene(η 5 -cyclopentadienyl)(η 5 [-octamethyloctahydrodibenzofluorene)]zirconium dichloride, [methylphenylmethylene(η 5 -cyclopentadienyl)(η 5 [Tetramethyloctahydrodibenzofluorene]zirconium dichloride, [methyl(3-methylphenyl)methylene(η) 5 -cyclopentadienyl)(η 5 [-fluorene)]zirconium dichloride, [methyl(3-methylphenyl)methylene(η) 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorene)]zirconium dichloride, [methyl(3-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorene)]zirconium dichloride, [methyl(3-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 [-octamethyloctahydrodibenzofluorene)]zirconium dichloride, [methyl(3-methylphenyl)methylene(η) 5 -cyclopentadienyl)(η 5 [Tetramethyloctahydrodibenzofluorenyl]zirconium dichloride, [diphenylmethylenesilyl(η)] 5 -cyclopentadienyl)(η 5 [-fluoreneyl)]zirconium dichloride, [diphenylmethylenesilyl(η) 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorene)]zirconium dichloride, [diphenylmethylenesilyl(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorene)]zirconium dichloride, [diphenylmethylenesilyl(H 5 -cyclopentadienyl)(η 5 [-octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [diphenylmethylenesilyl(η)] 5 -cyclopentadienyl)(η 5 [Tetramethyloctahydrodibenzofluorene]zirconium dichloride, [bis(3-methylphenyl)methylenesilyl(η) 5 -cyclopentadienyl)(η 5 [-fluorenyl)]zirconium dichloride, [bis(3-methylphenyl)methylenesilyl(η) 5-cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorene)]zirconium dichloride, [bis(3-methylphenyl)methylenesilyl(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorene)]zirconium dichloride, [bis(3-methylphenyl)methylenesilyl(η 5 -cyclopentadienyl)(η 5 [-octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [bis(3-methylphenyl)methylenesilyl(η)] 5 -cyclopentadienyl)(η 5 [Tetramethyloctahydrodibenzofluorenyl]zirconium dichloride, [dicyclohexylmethylenesilyl] 5 -cyclopentadienyl)(η 5 [-fluorene)]zirconium dichloride, [dicyclohexylmethylenesilyl(η)] 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorene)]zirconium dichloride, [dicyclohexylmethylenesilyl(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorene)]zirconium dichloride, [dicyclohexylmethylenesilyl(η 5 -cyclopentadienyl)(η 5 [-octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [dicyclohexylmethylenesilyl(η)] 5 -cyclopentadienyl)(η 5 [Tetramethyloctahydrodibenzofluorene]zirconium dichloride, [Ethylene(η) 5 -cyclopentadienyl)(η 5 [-fluorene)]zirconium dichloride, [ethylene(η) 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorene)]zirconium dichloride, [ethylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorene)]zirconium dichloride, [ethylene(η 5 -cyclopentadienyl)(η 5 [-octamethyloctahydrodibenzofluorene)]zirconium dichloride, [ethylene(η 5 -cyclopentadienyl)(η 5 [Tetramethyloctahydrodibenzofluorenyl]zirconium dichloride, etc.

[0151] Examples of compounds obtained by replacing zirconium atoms with hafnium atoms or by replacing chlorine ligands with methyl groups may be given, but the bridged metallocene compound (a) is not limited to these examples. It should be noted that, respectively, η, which constitutes a component of the illustrated bridged metallocene compound (a),... 5-Tetramethyloctahydrodibenzofluorenyl represents 4,4,7,7-tetramethyl-(5a,5b,11a,12,12a-η 5 )-1,2,3,4,7,8,9,10-octahydrodibenz[b,h]fluorenyl, η 5 -Octamethyloctahydrodibenzofluorenyl represents 1,1,4,4,7,7,10,10-octamethyl-(5a,5b,11a,12,12a-η 5 )-1,2,3,4,7,8,9,10-octahydrodibenz[b,h]fluorenyl.

[0152] <Compound (b)>

[0153] The polymerization catalyst used in the present invention comprises the bridged metallocene compound (a) described above and at least one compound (b) selected from the group consisting of an organometallic compound (b-1), an organoaluminum oxide compound (b-2), and a compound (b-3) that forms an ion pair by reacting with the bridged metallocene compound (a).

[0154] As the organometallic compound (b-1), specifically, organometallic compounds of Groups 1, 2, 12, and 13 of the periodic table as described below can be used.

[0155] (b-1a) General formula R a m Al(OR b ) n H p X q represents an organoaluminum compound.

[0156] (In the formula, 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, X represents a halogen atom, m is a number of 0 < m ≤ 3, n is a number of 0 ≤ n < 3, p is a number of 0 ≤ p < 3, q is a number of 0 ≤ q < 3, and m + n + p + q = <3)

[0157] As such compounds, examples include tri-n-alkylaluminums such as trimethylaluminum, triethylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, tri-branched alkylaluminums such as triisopropylaluminum, triisobutylaluminum, tri-sec-butylaluminum, tri-tert-butylaluminum, tri-2-methylbutylaluminum, tri-3-methylhexylaluminum, tri-2-ethylhexylaluminum, tri-cycloalkylaluminums such as tricyclohexylaluminum, tricyclooctylaluminum, tri-arylaluminums such as triphenylaluminum, tri(4-methylphenyl)aluminum, di-alkylaluminum hydrides such as diisopropylaluminum hydride, diisobutylaluminum hydride, and the general formula (i-C4H9) x Al y (C5H 10 ) z(In the formula, x, y, and z are positive numbers, and z ≤ 2x.) represents alkenyl aluminum such as isoprene aluminum, alkylalkanol aluminum such as isobutylmethoxide aluminum and isobutylethoxide aluminum, dimethylmethoxide aluminum, diethylethoxide aluminum, dibutylbutanol aluminum such as dialkylalkanol aluminum, ethyl sesquiethanol aluminum, butyl sesquibutanol aluminum and other alkyl sesquiethanol aluminum, and aluminum with the general formula R. a 2.5 Al(OR b ) 0.5 The average composition represented by alkyl aluminum, diethylphenol aluminum, diethyl(2,6-di-tert-butyl-4-methylphenol) aluminum, and other alkylaryloxy aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, dibutyl aluminum chloride, diethyl aluminum bromide, diisobutyl aluminum chloride, and other dialkyl aluminum halides, ethyl silsesquichloride, butyl silsesquichloride, ethyl silsesquibromide, and other alkyl silsesquihalides, ethyl aluminum dichloride, and other alkyl dihalides, and other partially halogenated alkyl aluminum, diethyl aluminum hydride, dibutyl aluminum hydride, ethyl aluminum dihydride, propyl aluminum dihydride, and other partially hydrogenated alkyl aluminum, ethyl ethoxy aluminum chloride, butyl butoxy aluminum chloride, ethyl ethoxy aluminum bromide, and other partially alkoxylated and halogenated alkyl aluminum, etc. Additionally, alkyl aluminum with the above general formula R can also be used. a m Al(OR b ) n H p X q Compounds similar to the one mentioned can be exemplified by organoaluminum compounds, which consist of two or more aluminum compounds bonded together by nitrogen atoms. Specifically, examples of such compounds include (C₂H₅)₂AlN(C₂H₅)Al(C₂H₅)₂.

[0158] (b-1b) General formula M 2 AlR a 4 represents the alkyl complex of a Group 1 metal of the periodic table with aluminum. (where M is an alkyl complex of a Group 1 metal of the periodic table.) 2 Represents Li, Na, or K, R a (This refers to a hydrocarbon group with 1 to 15 carbon atoms, preferably 1 to 4.)

[0159] Examples of such compounds include LiAl(C2H5)4 and LiAl(C7H5)4. 15 )4 etc.

[0160] (b-1c) General formula R a R b M 3 Represents a dialkyl compound of a metal from Group 2 or Group 12 of the periodic table. (Where R is an element) a and R bThey can be the same or different, representing hydrocarbon groups with 1 to 15 carbon atoms, preferably 1 to 4, M 3 (It can be Mg, Zn, or Cd.)

[0161] As organoaluminum oxides (b-2), conventionally known aluminum oxides can be used directly. Specifically, compounds represented by the following general formula [IV] and compounds represented by the following general formula [V] can be cited.

[0162] [Chemical Formula 5]

[0163]

[0164] In formulas [IV] and [V], R represents a hydrocarbon group with 1 to 10 carbon atoms, and n represents an integer greater than 2.

[0165] In particular, methylaluminoxanes in which R is methyl and n is 3 or more, preferably 10 or more, can be used. Several organoaluminum compounds can also be mixed into these aluminumoxanes.

[0166] In this invention, when copolymerizing ethylene with α-olefins having 3 or more carbon atoms at high temperatures, benzene-insoluble organoaluminum oxide compounds, as exemplified in Japanese Patent Application Publication No. 2-78687, can also be used. Alternatively, organoaluminum oxide compounds described in Japanese Patent Application Publication No. 2-167305, and aluminum oxides having two or more alkyl groups described in Japanese Patent Application Publication No. 2-24701 and Japanese Patent Application Publication No. 3-103407 are preferred. It should be noted that the term "benzene-insoluble organoaluminum oxide compound" sometimes used in this invention refers to a compound whose Al content, calculated in terms of Al atoms, is typically 10% or less, preferably 5% or less, and particularly preferably 2% or less in benzene at 60°C, and which is insoluble or poorly soluble relative to benzene.

[0167] In addition, as organoaluminum oxides (b-2), examples include modified methylaluminoxanes represented by the following general formula [VI].

[0168] [Chemical Formula 6]

[0169]

[0170] In formula [VI], R represents a hydrocarbon group with 1 to 10 carbon atoms, and m and n each independently represent integers of 2 or more.

[0171] This modified methylaluminoxane is a compound prepared using trimethylaluminum and alkylaluminum other than trimethylaluminum. Such compounds are commonly referred to as MMAO. Such MMAO can be prepared using the methods described in U.S. Patent Nos. 4,960,878 and 5,041,584. Additionally, substances with R being isobutyl, prepared using trimethylaluminum and triisobutylaluminum, are also commercially available under names such as MMAO and TMAO by companies such as Tosoh-Finechem. Such MMAO is an aluminum oxane with improved solubility and storage stability in various solvents; specifically, unlike the compounds represented by formula [IV] and [V] which are insoluble or sparingly soluble relative to benzene, it is soluble in aliphatic hydrocarbons and alicyclic hydrocarbons.

[0172] In addition, as organoaluminum oxides (b-2), organoaluminum oxides containing boron represented by the following general formula [VII] can also be cited.

[0173] [Chemical Formula 7]

[0174]

[0175] In equation [VII], R c R represents a hydrocarbon group with 1 to 10 carbon atoms. d They can be the same or different, representing hydrogen atoms, halogen atoms or hydrocarbon groups with 1 to 10 carbon atoms.

[0176] Examples of compounds (b-3) that form ion pairs with bridged metallocene compounds (a) (hereinafter sometimes simply referred to as "ionized ionic compounds" or simply "ionic compounds") include Lewis acids, ionic compounds, borane compounds, and carborane compounds described in Japanese Patent Application Publications Nos. 1-501950, 1-502036, 3-179005, 3-179006, 3-207703, 3-207704, and US Patent No. 5321106. In addition, heteropoly compounds and homopoly compounds may also be cited.

[0177] The preferred ionized ionic compound used in this invention is a boron compound represented by the following general formula [VIII].

[0178] [Chemical Formula 8]

[0179]

[0180] In equation [VIII], as R e+ H can be cited as an example. +Carbium cations, oxonium cations, ammonium cations, phosphonium cations, cycloheptyltrienyl cations, and ferrocene cations containing transition metals, etc. R f ~R i They may be the same or different from each other, and are substituents selected from hydrocarbon groups, silicon-containing groups, nitrogen-containing groups, oxygen-containing groups, halogen atoms and halogen-containing groups with 1 to 20 carbon atoms, preferably substituted aryl groups.

[0181] Specifically, examples of the aforementioned carbium cations include triphenylcarbium cations, tri(4-methylphenyl)carbium cations, tri(3,5-dimethylphenyl)carbium cations, and other trisubstituted carbium cations.

[0182] Specifically, examples of the aforementioned ammonium cations include trialkyl-substituted ammonium cations such as trimethylammonium cation, triethylammonium cation, tri(n-propyl)ammonium cation, triisopropylammonium cation, tri(n-butyl)ammonium cation, and triisobutylammonium cation; N,N-dimethylaniline-onium cation, N,N-diethylaniline-onium cation, and N,N-2,4,6-pentamethylaniline-onium cation; and dialkylammonium cations such as diisopropylammonium cation and dicyclohexylammonium cation.

[0183] Specifically, examples of phosphonium cations include triphenylphosphonium cations, tri(4-methylphenyl)phosphonium cations, tri(3,5-dimethylphenyl)phosphonium cations, and triarylphosphonium cations.

[0184] In the specific example above, as R e+ Preferably, it contains carbium cations, ammonium cations, etc., and particularly preferably triphenylcarbium cations, N,N-dimethylaniline cations, and N,N-diethylaniline cations.

[0185] Among the ionized ionic compounds preferably used in this invention, examples of compounds containing carbium cations include triphenylcarbium tetraphenylborate, triphenylcarbium tetra(pentafluorophenyl)borate, triphenylcarbium tetra{3,5-di-(trifluoromethyl)phenyl}borate, tri(4-methylphenyl)carbium tetra(pentafluorophenyl)borate, and tri(3,5-dimethylphenyl)carbium tetra(pentafluorophenyl)borate.

[0186] Among the ionized ionic compounds preferably used in this invention, examples of compounds containing trialkyl-substituted ammonium cations include triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri(n-butyl)ammonium tetraphenylborate, trimethylammonium tetra(4-methylphenyl)borate, trimethylammonium tetra(2-methylphenyl)borate, tri(n-butyl)ammonium tetra(pentafluorophenyl)borate, triethylammonium tetra(pentafluorophenyl)borate, tripropylammonium tetra(pentafluorophenyl)borate, tripropylammonium tetra(2,4-dimethylphenyl)borate, tri(n-butyl)ammonium tetra(3,5-dimethylphenyl)borate, tri(n-butyl)ammonium tetra{4-(trifluoromethyl)phenyl}borate, and tri(n-butyl)ammonium tetra{3, Tri(n-butyl)ammonium 5-bis(trifluoromethyl)phenyl}borate, tri(n-butyl)ammonium tetra(2-methylphenyl)borate, dioctadecylmethylammonium tetraphenylborate, dioctadecylmethylammonium tetra(4-methylphenyl)borate, dioctadecylmethylammonium tetra(4-methylphenyl)borate, dioctadecylmethylammonium tetra(pentafluorophenyl)borate, dioctadecylmethylammonium tetra(2,4-dimethylphenyl)borate, dioctadecylmethylammonium tetra(3,5-dimethylphenyl)borate, dioctadecylmethylammonium tetra{4-(trifluoromethyl)phenyl}borate, dioctadecylmethylammonium tetra{3,5-bis(trifluoromethyl)phenyl}borate, dioctadecylmethylammonium, etc.

[0187] Among the ionized ionic compounds preferably used in this invention, examples of compounds containing the N,N-dialkylaniline cation include N,N-dimethylaniline tetraphenylboronic acid, N,N-dimethylaniline tetra(pentafluorophenyl)boronic acid, N,N-dimethylaniline tetra(3,5-di(trifluoromethyl)phenyl)boronic acid, N,N-diethylaniline tetraphenylboronic acid, N,N-diethylaniline tetra(pentafluorophenyl)boronic acid, N,N-diethylaniline tetra(3,5-di(trifluoromethyl)phenyl)boronic acid, N,N-2,4,6-pentamethylaniline tetraphenylboronic acid, and N,N-2,4,6-pentamethylaniline tetra(pentafluorophenyl)boronic acid.

[0188] Among the ionized ionic compounds preferably used in this invention, examples of compounds containing dialkylammonium cations include di-n-propylammonium tetra(pentafluorophenyl)borate and dicyclohexylammonium tetraphenylborate.

[0189] In addition, ionic compounds illustrated in Japanese Patent Application Publication No. 2004-51676 may be used without restriction.

[0190] The aforementioned ionic compound (b-3) can be used alone or in combination of two or more.

[0191] As organometallic compounds (b-1), trimethylaluminum, triethylaluminum, and triisobutylaluminum, which are readily available as commercially available products, are preferred. Among them, triisobutylaluminum, which is easy to handle, is particularly preferred.

[0192] As organoaluminum oxide compounds (b-2), methylaluminoxane, which is readily available as a commercially available product, and MMAO prepared using trimethylaluminum and triisobutylaluminum are preferred. Among these, MMAO with improved solubility and storage stability in various solvents is particularly preferred.

[0193] As ionic compounds (b-3), triphenylcarbazium tetra(pentafluorophenyl)borate and N,N-dimethylaniline tetra(pentafluorophenyl)borate are preferred because they are readily available in commercially available forms and contribute significantly to improving polymerization activity.

[0194] As compound (b), combinations of triisobutylaluminum and triphenylcarbazium tetra(pentafluorophenyl)borate, and combinations of triisobutylaluminum and N,N-dimethylaniline ontium tetra(pentafluorophenyl)borate are particularly preferred, because they significantly enhance polymerization activity.

[0195] <Carrier (c)>

[0196] In this invention, the support (c) can be used as a component of the olefin polymerization catalyst as needed.

[0197] The support (c) used in this invention can be an inorganic or organic compound, and is a particulate or microparticle solid. Preferably, the inorganic compound is a porous oxide, inorganic chloride, clay, clay mineral, or an ion-exchangeable layered compound.

[0198] Specifically, porous oxides such as SiO2, Al2O3, MgO, ZrO, TiO2, B2O3, CaO, ZnO, BaO, ThO2, etc., or complexes or mixtures containing them, such as natural or synthetic zeolites, SiO2-MgO, SiO2-Al2O3, SiO2-TiO2, SiO2-V2O5, SiO2-Cr2O3, SiO2-TiO2-MgO, etc., can be used. Among these, porous oxides with SiO2 and / or Al2O3 as the main components are preferred. For such porous oxides, their properties vary depending on the type and preparation method. In this invention, the preferred support has a particle size of 0.5–300 μm, preferably 1.0–200 μm, and a specific surface area of ​​50–1000 m². 2 / g, preferably 100-700m 2 Within the range of / g, the pore volume is 0.3–3.0 cm³. 3Within the range of / g. Such a support can be used after being fired at 100–1000℃, preferably 150–700℃, as needed.

[0199] As inorganic chlorides, MgCl2, MgBr2, MnCl2, and MnBr2 can be used. Inorganic chlorides can be used directly or after being pulverized using a ball mill or vibratory mill. Alternatively, they can be used to obtain substances by dissolving inorganic chlorides in solvents such as alcohols and then using a precipitating agent to precipitate them in particulate form.

[0200] Clay is typically composed primarily of clay minerals. Ion-exchangeable layered compounds are compounds with a crystal structure in which the contained ions are exchangeable; this crystal structure is formed by the weakly bonded parallel layers of the constituent faces, such as ionic bonds. Most clay minerals are ion-exchangeable layered compounds. Furthermore, these clays, clay minerals, and ion-exchangeable layered compounds are not limited to natural products; synthetic compounds can also be used. Examples of clays, clay minerals, or ion-exchangeable layered compounds include clays, clay minerals, and ionic crystalline compounds with layered crystal structures such as hexagonal close-packed, antimony-type, CdCl2-type, and CdI2-type. Examples of such clays and clay minerals include kaolin, bentonite, wood-knot clay, frog-eye clay, diaspore, ferrosilicon, pyrophyllite, mica, montmorillonite, vermiculite, chlorite, palygorskite, kaolinite, pearlite clay, dickite, halloysite, etc. Examples of ion-exchangeable layered compounds include crystalline acidic salts of polyvalent metals such as α-Zr(HAsO4)2·H2O, α-Zr(HPO4)2, α-Zr(KPO4)2·3H2O, α-Ti(HPO4)2, α-Ti(HAsO4)2·H2O, α-Sn(HPO4)2·H2O, γ-Zr(HPO4)2, γ-Ti(HPO4)2, and γ-Ti(NH4PO4)2·H2O. It is also preferable to chemically treat the clays and clay minerals used in this invention. Chemical treatments can be used to remove impurities adhering to the surface, and to influence the crystal structure of clay. Specifically, examples of chemical treatments include acid treatment, alkali treatment, salt treatment, and organic matter treatment.

[0201] Ion-exchangeable layered compounds are layered compounds that utilize ion exchange properties to expand the interlayer by exchanging exchangeable ions between the layers with other large-volume ions. These large-volume ions act as pillars supporting the layered structure and are usually called pillars. Furthermore, introducing other substances (guest compounds) into the interlayer of a layered compound as described above is called intercalation. Examples of guest compounds include cationic inorganic compounds such as TiCl4 and ZrCl4, metal alkoxides (where R is a hydrocarbon group, etc.) such as Ti(OR)4, Zr(OR)4, PO(OR)3, and B(OR)3, and [Al...]. 13 O4(OH) 24 ] 7+ [Zr4(OH)] 14 ] 2+ [Fe3O(OCOCH3)6] + These include metal hydroxide ions, etc. These compounds can be used alone or in combination of two or more. Furthermore, when inserting these compounds, polymers obtained by hydrolysis and condensation of metal alkoxides (R being a hydrocarbon group, etc.) such as Si(OR)4, Al(OR)3, and Ge(OR)4, as well as colloidal inorganic compounds such as SiO2, can coexist. Additionally, oxides generated by inserting the aforementioned metal hydroxide ions into the interlayer and then heating and dehydrating them can be cited as examples of supports.

[0202] Among them, clay or clay minerals are preferred, with montmorillonite, vermiculite, spatholite, mica and synthetic mica being particularly preferred.

[0203] Regarding the organic compounds used as supports (c), examples include particulate or microparticle solids with particle sizes ranging from 0.5 to 300 μm. Specifically, examples include (co)polymers mainly composed of α-olefins with 2 to 14 carbon atoms, such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene, or (co)polymers mainly composed of vinylcyclohexane and styrene, and their modified forms.

[0204] High-temperature polymerization can be carried out by using an olefin polymerization catalyst that can generate highly random (C)ethylene-α-olefin copolymers. That is, by using this olefin polymerization catalyst, the decrease in randomness of the (C)ethylene-α-olefin copolymers generated during high-temperature polymerization can be suppressed. In solution polymerization, the viscosity of the polymerization solution containing the generated (C)ethylene-α-olefin copolymer decreases at high temperatures; therefore, compared to low-temperature polymerization, the concentration of (C)ethylene-α-olefin copolymers in the polymerizer can be increased, resulting in increased productivity per polymerizer. The copolymerization of ethylene and α-olefins in this invention can be carried out using any method of liquid-phase polymerization such as solution polymerization, suspension polymerization (slurry polymerization), or gas-phase polymerization. From the viewpoint that the effects of this invention can be maximized as described above, solution polymerization is particularly preferred.

[0205] The method of use and order of addition of each component in the olefin polymerization catalyst can be arbitrarily selected. In addition, at least two or more of the components in the catalyst can be pre-contaminated.

[0206] Bridged metallocene compound (a) (hereinafter also referred to as "component (a)") is typically 10 in 1 liter of reaction volume. -9 ~10 -1 moles, preferably 10 -8 ~10 -2 Use quantities like moles.

[0207] The organometallic compound (b-1) (hereinafter also referred to as "component (b-1)") is used in an amount such that the molar ratio of component (b-1) to the transition metal atom (M) in component (a) [(b-1) / M] is typically 0.01 to 50,000, preferably 0.05 to 10,000.

[0208] The organoaluminum oxide compound (b-2) (hereinafter also referred to as "component (b-2)") is used in an amount such that the molar ratio of aluminum atoms in component (b-2) to transition metal atoms (M) in component (a) [(b-2) / M] is typically 10 to 5,000, preferably 20 to 2,000.

[0209] The ionic compound (b-3) (hereinafter also referred to as "component (b-3)") is used in an amount such that the molar ratio of component (b-3) to the transition metal atom (M) in component (a) [(b-3) / M] is typically 1 to 10,000, preferably 1 to 5,000.

[0210] The polymerization temperature is typically -50°C to 300°C, preferably 30°C to 250°C, more preferably 100°C to 250°C, and even more preferably 130°C to 200°C. Within the aforementioned polymerization temperature range, as the temperature increases, the viscosity of the solution decreases, and the heat of polymerization is easily removed. The polymerization pressure is typically atmospheric pressure to 10 MPa gauge pressure (MPa-G), preferably atmospheric pressure to 8 MPa-G.

[0211] Polymerization reactions can be carried out using any of the following methods: batch, semi-continuous, or continuous. Furthermore, polymerization can be carried out continuously using two or more polymerizers with different reaction conditions.

[0212] The molecular weight of the resulting copolymer can be adjusted by changing the hydrogen concentration and polymerization temperature in the polymerization system. Alternatively, it can be adjusted by using the amount of component (b). When hydrogen is added, an amount of approximately 0.001 to 5,000 NL relative to the copolymer produced per 1 kg is appropriate.

[0213] The polymerization solvent used in liquid-phase polymerization is typically a non-reactive hydrocarbon solvent, preferably a saturated hydrocarbon with a boiling point of 50°C to 200°C at atmospheric pressure. Specifically, examples of polymerization solvents include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene, as well as alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane. Hexane, heptane, octane, decane, and cyclohexane are particularly preferred. The α-olefin itself, the target polymer, can also be used as a polymerization solvent. It should be noted that aromatic hydrocarbons such as benzene, toluene, and xylene, and halogenated hydrocarbons such as vinyl chloride, chlorobenzene, and dichloromethane can also be used as polymerization solvents, but from the perspective of reducing environmental burden and minimizing impact on human health, the use of these substances is not ideal.

[0214] The dynamic viscosity of olefin polymers at 100°C depends on the polymer's molecular weight. That is, a high molecular weight results in high viscosity, and a low molecular weight results in low viscosity. Therefore, the dynamic viscosity at 100°C can be adjusted by adjusting the molecular weight as described above. Furthermore, the molecular weight distribution (Mw / Mn) of the obtained polymer can be adjusted by removing the low molecular weight components using conventional methods such as vacuum distillation. In addition, the obtained polymer can be hydrogenated (hereinafter also referred to as hydrogenation) using conventional methods. If the number of double bonds in the polymer obtained by hydrogenation is reduced, the oxidative stability and heat resistance are improved.

[0215] The resulting (C) ethylene-α-olefin copolymer can be used alone, or two or more ethylene-α-olefin copolymers of different molecular weights or ethylene-α-olefin copolymers composed of different monomers can be combined.

[0216] Furthermore, regarding (C) ethylene-α-olefin copolymers, the functional groups can be grafted and modified, and they can also be further modified a second time. For example, methods described in Japanese Patent Application Publication No. 61-126120 and Japanese Patent Publication No. 2593264 can be cited, and methods described in Japanese Patent Publication No. 2008-508402 can be cited as examples of secondary modification.

[0217] [Lubricating Oil Composition for Working Oils]

[0218] The working oil lubricating oil composition of the present invention is characterized in that it contains a lubricating oil base oil formed from (A) mineral oil and / or (B) synthetic oil and the aforementioned lubricating oil viscosity modifier, and the dynamic viscosity and viscosity index at 40°C are within a specific range.

[0219] <(A) Mineral Oil>

[0220] (A) Mineral oil has the following characteristics (A1) to (A3).

[0221] (A1) The dynamic viscosity at 40℃ is 10–100 mm. 2 / s

[0222] The dynamic viscosity value at 40°C is the value measured according to the method described in JIS K2283. (A) The dynamic viscosity of mineral oil at 40°C is 10–100 mm. 2 / s, preferably 15–80 mm 2 / s, more preferably 20-60mm 2 / s. If the dynamic viscosity at 40°C is within this range, the lubricating oil composition of the present invention is excellent from the viewpoint of a balance between volatility and temperature viscosity characteristics.

[0223] (A2) Viscosity index above 90

[0224] The viscosity index value is the value measured according to the method described in JIS K2283. (A) The viscosity index of the mineral oil is 90 or higher, preferably 100 or higher, and more preferably 105 or higher. If the viscosity index is within this range, the lubricating oil composition of the present invention has excellent temperature viscosity characteristics.

[0225] (A3) Pour point below 0°C

[0226] The pour point value is the value determined according to the method described in ASTM D97. (A) The pour point of the mineral oil is below 0°C, preferably below -5°C, more preferably below -10°C, and even more preferably below -12°C. If the pour point is within this range, the lubricating oil composition of the present invention has excellent low-temperature viscosity characteristics.

[0227] <(B) Synthetic Oils>

[0228] (B) Synthetic oils have the following characteristics (B1) to (B3).

[0229] (B1) The dynamic viscosity at 40℃ is 4–100 mm. 2 / s

[0230] The dynamic viscosity value at 40°C is the value measured according to the method described in JIS K2283. (B) The dynamic viscosity of synthetic oil at 40°C is 4–100 mm. 2 / s, preferably 4.5~80mm 2 / s, more preferably 10 to 60 mm 2 / s. If the dynamic viscosity at 40°C is within this range, the lubricating oil composition of the present invention is excellent from the viewpoint of a balance between volatility and temperature viscosity characteristics.

[0231] (B2) Viscosity index above 90

[0232] The viscosity index value is the value measured according to the method described in JIS K2283. (B) The viscosity index of the synthetic oil is 90 or higher, preferably 110 or higher, more preferably 115 or higher, and even more preferably 120 or higher. If the viscosity index is within this range, the lubricating oil composition of the present invention has excellent temperature viscosity characteristics.

[0233] (B3) Pour point is below -30℃

[0234] The pour point value is the value determined according to the method described in ASTM D97. (B) The pour point of the synthetic oil is below -30°C, preferably below -40°C, more preferably below -50°C, and even more preferably below -60°C. If the pour point is within this range, the lubricating oil composition of the present invention has excellent low-temperature viscosity characteristics.

[0235] Regarding the lubricating oil base oil used in this invention, its viscosity characteristics, heat resistance, oxidation stability, and other properties and qualities vary depending on its manufacturing method, purification method, etc., but it is generally broadly classified into mineral oil and synthetic oil. Furthermore, the API (American Petroleum Institute) classifies lubricating oil base oils into five groups: Group 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. (A) Mineral oil can be any mineral oil from Groups I to III of the API categories; (B) Synthetic oil can be any synthetic oil from Groups IV and V of the API categories. Details are described below.

[0236] [Table 1]

[0237]

[0238] *1: Determined according to ASTM D445 (JIS K2283)

[0239] *2: Measured according to ASTM D3338

[0240] *3: Determined according to ASTM D4294 (JIS K2541)

[0241] *2: Mineral oils with less than 90 vol% saturated hydrocarbons and more than 0.03 wt% sulfur are also included in Group I.

[0242] <(A) Mineral Oil>

[0243] (A) Mineral oils belong to groups I to III of the API categories mentioned above.

[0244] (A) As described above, mineral oils of various qualities can be obtained through purification methods. Specifically, mineral oils can be exemplified as: products obtained by vacuum distillation of the atmospheric residual oil obtained from atmospheric distillation of crude oil, and by subjecting the resulting lubricating oil fraction to one or more of the following treatments: solvent deasphalting, solvent extraction, hydrogenation decomposition, solvent dewaxing, and hydrogenation purification; or lubricating oil base oils such as wax isomerized mineral oil.

[0245] In addition, gas-to-liquid (GTL) base oils obtained using the Fischer-Tropsch process are also suitable base oils for use as Group III mineral oils. Such GTL base oils are sometimes also treated as Group III+ lubricating oil base oils, as described, for example, in patent documents EP0776959, EP0668342, WO97 / 21788, WO00 / 15736, WO00 / 14188, WO00 / 14187, WO00 / 14183, WO00 / 14179, WO00 / 08115, WO99 / 41332, EP1029029, WO01 / 18156, and WO01 / 57166.

[0246] <(B) Synthetic Oils>

[0247] (B) Synthetic oils belong to Group IV or Group V of the API categories mentioned above.

[0248] Polyalphaolefins belonging to Group IV can be obtained by oligomerization reactions using acid catalysts such as boron trifluoride and chromic acid catalysts, as described in U.S. Patent Nos. 3,382,291, 3,763,244, 5,171,908, 3,780,128, 4,032,591, Japanese Patent Application Publication No. 1-163,136, 4,967,032, and 4,926,004. Alternatively, it can be obtained by using a catalyst system comprising metallocene compounds as described in Japanese Patent Application Publication Nos. 63-037102, 2005-200447, 2005-200448, 2009-503147, and 2009-501836, and using transition metal complexes such as zirconium, titanium, and hafnium. If polyalphaolefin is used as the aforementioned lubricating oil base, a lubricating oil composition with extremely excellent temperature viscosity characteristics, low-temperature viscosity characteristics, and heat resistance can be obtained.

[0249] Polyalphaolefins are also available industrially, with a dynamic viscosity of 5 mm at 40°C. 2 / s~4,000mm 2 Polyalphaolefins of 5-70 mm / s are already available on the market. 2Polyalphaolefins with a viscosity of / s can produce lubricating oil compositions with excellent temperature viscosity characteristics, which is preferred from this perspective. Examples include the NEXBASE2000 series from NESTE, Spectrasyn from ExxonMobil Chemical, Durasyn from Ineos Oligmers, and Synfluid from ChevronPhillips Chemical.

[0250] Synthetic oils belonging to group V include, for example, alkylbenzenes, alkylnaphthalenes, isobutylene oligomers or their hydrides, alkanes, polyoxyalkylene glycols, dialkyl diphenyl ethers, polyphenylene ethers, esters, etc.

[0251] Alkylbenzenes and alkylnaphthalenes are typically dialkylbenzenes or dialkylnaphthalenes with alkyl chains having 6 to 14 carbon atoms. These alkylbenzenes or alkylnaphthalenes can be produced by Friedel-Crafts alkylation of benzene or naphthalene with an olefin. The alkylating olefin used in the production of alkylbenzenes or alkylnaphthalenes can be linear or branched olefins or combinations thereof. Methods for their production are described, for example, in U.S. Patent No. 3,909,432.

[0252] Furthermore, from the viewpoint of compatibility with (C) ethylene-α-olefin copolymers, fatty acid esters are preferred. There are no particular limitations on fatty acid esters; examples include fatty acid esters formed solely of carbon, oxygen, and hydrogen, such as monoesters made from monobasic acids and alcohols; diesters made from dibasic acids and alcohols, or from diols and monobasic acids or mixtures thereof; and polyol esters made by reacting diols, triols (e.g., trimethylolpropane), tetraols (e.g., pentaerythritol), hexaols (e.g., dipentaerythritol), etc., with monobasic acids or mixtures thereof. Examples of these esters include ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, tridecyl nonanoate, di-2-ethylhexyl adipate, di-2-ethylhexyl azelate, trimethylolpropane octanoate, trimethylolpropane nonanoate, trimethylolpropane triheptanoate, pentaerythritol-2-ethylhexanoate, pentaerythritol nonanoate, and pentaerythritol tetraheptanoate.

[0253] From the viewpoint of compatibility with (C) ethylene-α-olefin copolymers, alcohols with a hydroxyl group of two or more functions are preferred as the alcohol site constituting the ester, and fatty acids with eight or more carbon atoms are preferred as the fatty acid site. However, regarding fatty acids, from the perspective of manufacturing cost, fatty acids with 20 or fewer carbon atoms that are readily available industrially are preferred. The fatty acid constituting the ester can be a single type, and the effects of the present invention can be fully utilized even when using a fatty acid ester manufactured using a mixture of two or more acids. More specifically, examples of fatty acid esters include trimethylolpropane laurate-stearic acid mixed triester and diisodecyl adipate, which are preferred from the perspective of compatibility between saturated hydrocarbon components such as (C) ethylene-α-olefin copolymers and stabilizers such as antioxidants, corrosion inhibitors, anti-wear agents, friction modifiers, pour point depressants, rust inhibitors, and defoamers with polar groups, as described later.

[0254] For the lubricating oil composition of the present invention, when using (B) synthetic oil, especially polyalphaolefin, as the lubricating oil base oil, and setting the total lubricating oil composition to 100% by mass, it is preferable to include fatty acid esters in an amount of 1 to 20% by mass. By containing more than 1% by mass of fatty acid esters, good adaptability can be obtained for lubricating oil sealing materials such as resins and elastomers inside various internal combustion engines and industrial machinery. Specifically, it is possible to suppress the swelling of lubricating oil sealing materials. From the viewpoint of oxidative stability or heat resistance, the amount of ester is preferably 20% by mass or less. When mineral oil is included in the lubricating oil composition, the mineral oil itself has the effect of suppressing the swelling of lubricating oil sealants, so fatty acid esters are not necessarily required.

[0255] (B) Synthetic oil has superior heat resistance and temperature viscosity characteristics compared to (A) mineral oil, and is therefore preferred. In the lubricating oil composition of the present invention, one of (A) mineral oil or (B) synthetic oil can be used alone as the lubricating oil base oil. Alternatively, any mixture of two or more lubricating oils selected from (A) mineral oil and (B) synthetic oil can be used.

[0256] The working oil lubricating oil composition of the present invention contains a lubricating oil base oil formed from the aforementioned (A) mineral oil and / or (B) synthetic oil and the aforementioned lubricating oil viscosity modifier, and has the following (D1) characteristics.

[0257] (D1) The dynamic viscosity at 40℃ is 28–170 mm. 2 / s

[0258] The dynamic viscosity at 40°C (measured according to the method described in JIS K2283) is 28–170 mmHg. 2 / s, preferably 30–110 mm 2 / s, more preferably 36-80mm2 / s, more preferably 40–75 mm 2 / s. If the dynamic viscosity of the working oil lubricating oil composition at 40°C is greater than 110 mm. 2 If the stirring torque increases by 28 mm / s, the hydraulic system using the lubricating oil composition will have poor energy efficiency. 2 If the oil film of the lubricating oil composition is not maintained at a certain speed ( / s), sufficient lubrication cannot be achieved.

[0259] Typically, the viscosity of industrial lubricants is specified using their dynamic viscosity at 40°C, with the viscosity range defined by JIS K2001 (according to ISO 3448). A 10% tolerance range is set above and below each viscosity. For example, a dynamic viscosity at 40°C of 68 mmHg... 2 The lubricating oil is labeled ISO VG68, and its permissible dynamic viscosity range at 40°C is 61.2–74.8 mm. 2 / s. The suitable range varies depending on the type of hydraulic system and operating conditions, but for hydraulic working fluids, ISO VG32 to ISO VG150 are preferred. When comparing performance, lubricant compositions of the same viscosity grade are typically compared to each other.

[0260] The working oil lubricating oil composition of the present invention preferably further has the characteristics of (D2) and (D3).

[0261] (D2) Viscosity index is above 120

[0262] The viscosity index (measured according to the method described in JIS K2283) is preferably 120 or higher, more preferably 130 or higher, even more preferably 140 or higher, and particularly preferably 150 or higher. If the viscosity index is within this range, the lubricating oil composition has excellent temperature viscosity characteristics, and can simultaneously achieve the aforementioned energy saving and lubrication properties over a wide temperature range.

[0263] (D3) Pour point is below -20℃

[0264] The pour point (determined according to the method described in ASTM D97) of the working oil lubricating oil composition of the present invention is preferably below -20°C, more preferably below -30°C, and even more preferably below -40°C. A low pour point indicates excellent low-temperature properties of the lubricating oil composition.

[0265] The working oil lubricating oil composition of the present invention preferably contains the aforementioned (C) ethylene-α-olefin copolymer in a proportion of 1 to 10% by mass, more preferably in a proportion of 2 to 10% by mass, even more preferably in a proportion of 3 to 8% by mass, and particularly preferably in a proportion of 4 to 7% by mass.

[0266] The working oil lubricating oil composition of the present invention preferably contains a lubricating oil base oil formed from the aforementioned (A) mineral oil and / or (B) synthetic oil in a proportion of 90-99% by mass, and a lubricating oil viscosity modifier in a proportion of 1-10% by mass. The total amount of the aforementioned lubricating oil base oil and the aforementioned lubricating oil viscosity modifier is set at 100% by mass. The working oil lubricating oil composition of the present invention preferably contains the aforementioned lubricating oil base oil in a proportion of 90-98% by mass, and the aforementioned lubricating oil viscosity modifier in a proportion of 2-10% by mass; more preferably, it contains the aforementioned lubricating oil base oil in a proportion of 92-97% by mass, and the aforementioned lubricating oil viscosity modifier in a proportion of 3-8% by mass; even more preferably, it contains the aforementioned lubricating oil base oil in a proportion of 93-96% by mass, and the aforementioned lubricating oil viscosity modifier in a proportion of 4-7% by mass.

[0267] As a preferred embodiment, the lubricating oil base oil may contain 30-100% by mass of (A) mineral oil. A high proportion of (A) mineral oil in the lubricating oil base oil results in excellent solubility of the additives described later, and also provides good availability and cost-effectiveness. More preferably, it contains 50-100% by mass of mineral oil, and even more preferably, 80-100% by mass. Among mineral oils, those from Group III of the API category exhibit excellent temperature viscosity characteristics, enabling simultaneous oil film retention at high temperatures and low torque at low temperatures, and are therefore preferred.

[0268] As another preferred embodiment, the lubricating oil base oil may contain 30-100% by mass of (B) synthetic oil, and (B) synthetic oil may be polyalphaolefin and / or ester oil. More preferably, it may contain 50-100% by mass of synthetic oil, and even more preferably, it may contain 80-100% by mass of synthetic oil. If the proportion of (B) synthetic oil in the lubricating oil base oil is high, it will exhibit excellent heat resistance, temperature viscosity characteristics, and low-temperature characteristics, which is preferred.

[0269] In addition, the working oil lubricating oil composition of the present invention may contain additives such as extreme pressure additives, detergents and dispersants, viscosity index improvers, antioxidants, corrosion inhibitors, anti-wear agents, friction modifiers, pour point depressants, rust inhibitors, and defoamers.

[0270] Examples of additives used in the lubricating oil composition of the present invention include the following additives, which can be used alone or in combination of two or more. Extreme pressure additives are a general term for substances that prevent seizing when metals are subjected to high loads. There are no particular limitations, and examples include sulfur-based extreme pressure additives such as sulfides, sulfoxides, sulfones, thiophosphinates, thiocarbonates, sulfurized greases, and sulfurized olefins; phosphoric acid compounds such as phosphate esters, phosphites, phosphate ester amine salts, and phosphite ester amines; and halogen compounds such as chlorinated hydrocarbons. Furthermore, two or more of these compounds can be used in combination.

[0271] It should be noted that before extreme pressure lubrication conditions are reached, hydrocarbons or other organic components constituting the lubricating oil composition may carbonize under the influence of heating and shearing, forming a carbide film on the metal surface. Therefore, when extreme pressure additives are used alone, the contact between the additives and the metal surface is hindered by the carbide film, and the full effect of the extreme pressure additives may not be expected.

[0272] While extreme pressure additives can be added individually, since the working oil lubricating oil composition of the present invention is mainly composed of saturated hydrocarbons such as copolymers, from the viewpoint of dispersibility, it is preferable to add them in a state where they are pre-dissolved together with other additives used in a lubricating oil base such as mineral oil or synthetic hydrocarbon oil. Specifically, a more preferred method is to select a so-called additive package and add it to the lubricating oil composition, wherein the additive package is obtained by pre-combining various components such as extreme pressure additive components and then dissolving them in a lubricating oil base such as mineral oil or synthetic hydrocarbon oil.

[0273] Preferred additives include Anglamol-98A, Anglamol-6043, Angramol 6085U, and Lubrizol 1047U manufactured by LUBRIZOL; HITEC1532, HITEC307, and HITEC3339 manufactured by AFTON CHEMICAL; and Additin RC9410 manufactured by LANXESS.

[0274] Extreme pressure additives can be used as needed in the range of 0 to 10% by mass relative to 100% by mass of the lubricating oil composition. Examples of anti-wear agents include inorganic or organic molybdenum compounds such as molybdenum disulfide, graphite, antimony sulfide, and polytetrafluoroethylene. Anti-wear agents can be used as needed in the range of 0 to 3% by mass relative to 100% by mass of the lubricating oil composition.

[0275] Examples of friction modifiers include amine compounds, imide compounds, fatty acid esters, fatty acid amides, and fatty acid metal salts, which have at least one alkyl or alkenyl group having 6 to 30 carbon atoms in the molecule, especially straight-chain alkyl or alkenyl groups having 6 to 30 carbon atoms.

[0276] Examples of amine compounds include: linear or branched aliphatic monoamines, preferably linear, having 6 to 30 carbon atoms; linear or branched aliphatic polyamines, preferably linear; or alkylene oxide adducts of these aliphatic amines. Examples of imide compounds include succinimides having 6 to 30 carbon atoms, either linear or branched, with alkyl or alkenyl groups, and / or modified compounds obtained using carboxylic acids, boric acids, phosphoric acids, sulfuric acids, etc. Examples of fatty acid esters include esters formed from linear or branched fatty acids, preferably linear, having 7 to 31 carbon atoms, and aliphatic monohydric or polyhydric alcohols. Examples of fatty acid amides include amides formed from linear or branched fatty acids, preferably linear, having 7 to 31 carbon atoms, and aliphatic monoamines or polyamines. Examples of fatty acid metal salts include alkaline earth metal salts (magnesium salts, calcium salts, etc.) of fatty acids with 7 to 31 carbon atoms, preferably straight-chain or branched salts, and zinc salts.

[0277] Friction modifiers can be used as needed in the range of 0.01 to 5.0% by mass relative to 100% by mass of the lubricating oil composition.

[0278] Examples of detergent-dispersants include metal sulfonates, metal phenolates, metal phosphonates, and succinimides. The detergent-dispersant can be used as needed in the range of 0 to 15% by mass relative to 100% by mass of the lubricating oil composition.

[0279] As a viscosity index improver, in addition to ethylene-α-olefin copolymers (excluding (C) ethylene-α-olefin copolymers), it can also be used with olefin copolymers with a molecular weight greater than 50,000, methacrylate copolymers, liquid polybutene, and a dynamic viscosity of 15 mm at 100°C. 2 Known viscosity index improvers such as polyalphaolefins with a viscosity index of 1 / s or higher. Viscosity index improvers can be used as needed in the range of 0 to 50% by mass relative to 100% by mass of the lubricating oil composition.

[0280] Examples of antioxidants include phenolic and amine compounds such as 2,6-di-tert-butyl-4-methylphenol. Antioxidants can be used as needed in the range of 0 to 3% by mass relative to 100% by mass of the lubricating oil composition.

[0281] Examples of corrosion inhibitors include benzotriazole, benzimidazole, and thiadiazole. Corrosion inhibitors can be used as needed in the range of 0 to 3% by mass relative to 100% by mass of the lubricating oil composition.

[0282] Examples of rust inhibitors include various amine compounds, metal salts of carboxylic acids, polyol esters, phosphorus compounds, sulfonates, and other compounds. Rust inhibitors can be used as needed in the range of 0 to 3% by mass relative to 100% by mass of the lubricating oil composition.

[0283] Examples of defoamers include organosilicon compounds such as dimethylsiloxane and silica gel dispersions, as well as alcohol or ester compounds. The defoamer can be used as needed in the range of 0 to 0.2% by mass relative to 100% by mass of the lubricating oil composition.

[0284] Various known pour point depressants can be used as pour point depressants. Specifically, polymers containing organic ester groups can be used, and vinyl polymers containing organic ester groups are particularly suitable. Examples of vinyl polymers containing organic ester groups include (co)polymers of alkyl methacrylates, (co)polymers of alkyl acrylates, (co)polymers of alkyl fumarates, (co)polymers of alkyl maleate, alkylated naphthalene, etc.

[0285] Such a pour point depressant has a melting point below -13°C, preferably -15°C, and more preferably below -17°C. The melting point of the pour point depressant can be determined using a differential scanning calorimeter (DSC). Specifically, approximately 5 mg of sample is packed into an aluminum dish, heated to 200°C, held at 200°C for 5 minutes, then cooled to -40°C at a rate of 10°C / min, held at -40°C for 5 minutes, and then heated at a rate of 10°C / min. The melting point is then determined from the endothermic curve.

[0286] Furthermore, for the aforementioned pour point depressant, the weight-average molecular weight (based on polystyrene) obtained by gel permeation chromatography is in the range of 20,000 to 400,000, preferably in the range of 30,000 to 300,000, and more preferably in the range of 40,000 to 200,000.

[0287] Pour point depressants can be used as needed in the range of 0 to 2% by mass relative to 100% by mass of the lubricating oil composition.

[0288] In addition to the additives mentioned above, demulsifiers, colorants, and oiliness agents (oiliness improvers) can also be used as needed.

[0289] <Applications>

[0290] The lubricating oil composition of the present invention can be suitably used as the working oil for various industrial machines and transportation machines. Compared with the existing lubricating oils containing the same lubricating base oil, it has extremely excellent temperature-viscosity characteristics, namely, oil film retention at high temperatures and low-temperature viscosity characteristics, and can greatly contribute to energy saving in the hydraulic pressure system. In addition, it has excellent shear stability, so it maintains the lubricating performance during long-term use of the hydraulic pressure system and helps to maintain the performance of the system. The lubricating oil composition of the present invention is extremely useful as the hydraulic pressure working oil for machine tools, the hydraulic pressure working oil for molding machines, and the hydraulic pressure working oil for construction machines in particular.

[0291] Examples

[0292] Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

[0293] [Evaluation method]

[0294] In the following examples, comparative examples, etc., the physical properties of the ethylene-α-olefin copolymer and the working oil were measured by the following methods.

[0295] <Ethylene content (mol%)>

[0296] Using a Fourier transform infrared spectrophotometer FT / IR-610 or FT / IR-6100 manufactured by JASCO Corporation, calculate the absorbance ratio (D1155 cm -1 near 1155 cm which is based on the skeletal vibration of propylene and the absorption near 721 cmwhich is based on the rocking vibration of long-chain methylene. -1 near 721 cm (D1155 cm -1 / D721 cm -1 ), and use the pre-made standard curve (made using the standard samples in ASTM D3900) to find the ethylene content (wt%). Next, using the obtained ethylene content (wt%), calculate the ethylene content (mol%) according to the following formula.

[0297] [Mathematical formula 3]

[0298]

[0299] <Rotational viscosity at 150 °C>

[0300] For the rotational viscosity at 150 °C, measure it using a B-type viscometer according to the method described in JIS Z8803.

[0301] <Hazen color>

[0302] Find the Hazen color (APHA value) according to the method described in JIS K0071.

[0303]

[0304] Using o-dichlorobenzene / benzene-d6 (4 / 1 [vol / vol%]) as the assay solvent, measurements were performed under the following conditions: a measurement temperature of 120°C, a spectral width of 250 ppm, a pulse repetition time of 5.5 seconds, and a pulse width of 4.7 μsec (45° pulse) (100 MHz, NEC Electronics ECX400P); or a measurement temperature of 120°C, a spectral width of 250 ppm, a pulse repetition time of 5.5 seconds, and a pulse width of 5.0 μsec (45° pulse) (125 MHz, Bruker Biospin AVANCE III cryo-500). 13 C-NMR spectra, the B value is calculated based on the following formula [1]. The peak assignment is based on the aforementioned known literature.

[0305] [Mathematical Expression 4]

[0306]

[0307] In formula [1], P E P represents the mole fraction of ethylene. O P represents the molar fraction of α-olefin components. OE This represents the mole fraction of the ethylene-α-olefin chain in the entire binary chain.

[0308] <Weight-average molecular weight, molecular weight distribution>

[0309] The molecular weight distribution was determined using a Tosoh HLC-8320GPC as described below. A four-column TSKgel SuperMultipore HZ-M column was used as the separation column at 40°C. Tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.) was used as the mobile phase, with a development rate of 0.35 ml / min, a sample concentration of 5.5 g / L, and a sample injection volume of 20 μL. A differential refractometer was used as the detector. Tosoh PStQuick MP-M standard polystyrene was used as the standard. Following general calibration procedures, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were calculated based on the polystyrene molecular weight, and the molecular weight distribution (Mw / Mn) was calculated from their values.

[0310] Melting point

[0311] Using a Seiko Instruments Inc. X-DSC-7000, approximately 8 mg of ethylene-α-olefin copolymer was placed in an easily sealable aluminum sample pan within the DSC unit. Under a nitrogen atmosphere, the DSC unit was heated from room temperature to 150°C at a rate of 10°C / min. After holding at 150°C for 5 minutes, the unit was cooled to -100°C at a rate of 10°C / min (during the cooling process). Next, after holding at -100°C for 5 minutes, the temperature was increased at a rate of 10°C / min. The temperature at which the enthalpy curve obtained during the heating process showed a maximum value was taken as the melting point (Tm), and the total heat absorbed during melting was taken as the heat of fusion (ΔH). If no peak was observed, or the heat of fusion (ΔH) was below 1 J / g, it was considered to have no melting point (Tm). The methods for determining the melting point (Tm) and heat of fusion (ΔH) were based on JIS K7121.

[0312] Chlorine content

[0313] Using a Thermo Fisher Scientific ICS-1600, the ethylene-α-olefin copolymer was loaded into a sample boat and subjected to combustion decomposition in an Ar / O2 gas stream at a set temperature of 900°C. The generated gas was absorbed into an absorbent, and the chlorine content was quantified using ion chromatography.

[0314] <Metrological Accuracy>

[0315] 100g of polymer heated to 80°C was added to a 2L detachable flask placed on an electronic balance using a gear pump. After stopping the pump, the amount of liquid dripping from the outlet was checked. A case where the error relative to the specified weight was greater than 5% was considered as liquid dripping during measurement.

[0316] <Solubility>

[0317] Weigh 100g of the polymer into a 2L detachable flask, add 900g of the mineral oil (described later), heat to 80°C, and stir at 100rpm using a stir bar. Visually measure the time required for complete and uniform dissolution every 30 minutes. If undissolved material is still visible after 3 hours of stirring, the mixture is considered "undissolved".

[0318] <Dynamic viscosity>

[0319] The dynamic viscosity at 100°C and the dynamic viscosity at 40°C were determined according to the method described in JIS K2283.

[0320] Low-temperature viscosity

[0321] For low-temperature viscosity, the viscosity at -40°C was determined using the method described in ASTM D6821. Viscosities greater than 200,000 mPa·s were considered unmeasurable.

[0322] <Shear stability>

[0323] Regarding the shear stability of the lubricating oil composition, a shear test was conducted on the lubricating oil composition using a KRL shear testing machine according to the method described in CRC L-45-T-93, under shear conditions of 20 hours, 60°C, and 1450 rpm. The dynamic viscosity at 40°C after the test was then determined.

[0324] [Manufacturing of ethylene-α-olefin copolymer (B)]

[0325] The ethylene-α-olefin copolymer (B) is manufactured according to the following polymerization example. It should be noted that the resulting ethylene-α-olefin copolymer (B) is hydrogenated as needed using the method described below.

[0326] <Hydrogenation Operation>

[0327] 100 mL of a hexane solution containing 0.5% by mass Pd / alumina catalyst and 500 mL of a hexane solution containing 30% by mass ethylene-α-olefin copolymer were added to a 1 L stainless steel autoclave. After sealing the autoclave, nitrogen replacement was performed. Then, the temperature was raised to 140 °C while stirring to perform hydrogen replacement in the system. The pressure was then increased to 1.5 MPa using hydrogen, and a hydrogenation reaction was carried out for 15 minutes.

[0328] Synthesis of Metallocene Compounds

[0329] [Synthesis example 1]

[0330] [Methylphenylmethylene (η)] 5 -cyclopentadienyl)(η 5 Synthesis of [-2,7-di-tert-butylfluorene]zirconium dichloride

[0331] (i) Synthesis of 6-methyl-6-phenyl-fullen

[0332] Under a nitrogen atmosphere, 7.3 g (101.6 mmol) of lithium cyclopentadiene and 100 mL of anhydrous tetrahydrofuran were added to a 200 mL three-necked flask and stirred. The solution was cooled in an ice bath, and 15.0 g (111.8 mmol) of acetophenone was added dropwise. The mixture was then stirred at room temperature for 20 hours, and the resulting solution was quenched with dilute hydrochloric acid aqueous solution. 100 mL of hexane was added to extract the soluble components. The organic layer was washed with water and saturated brine, and dried over anhydrous magnesium sulfate. The solvent was then removed by distillation, and the resulting viscous liquid was separated by column chromatography (hexane) to obtain the target analyte (red viscous liquid).

[0333] (ii) Synthesis of methyl(cyclopentadienyl)(2,7-di-tert-butylfluorenyl)(phenyl)methane

[0334] Under a nitrogen atmosphere, 2.01 g (7.20 mmol) of 2,7-di-tert-butylfluorene and 50 mL of anhydrous tert-butyl methyl ether were added to a 100 mL three-necked flask. While cooling in an ice bath, 4.60 mL (7.59 mmol) of a 1.65 M butyllithium / hexane solution was slowly added, and the mixture was stirred at room temperature for 16 hours. Then, 1.66 g (9.85 mmol) of 6-methyl-6-phenylfulne was added, and the mixture was stirred under reflux for 1 hour. While cooling in an ice bath, 50 mL of water was slowly added, and the resulting two-layer solution was transferred to a 200 mL separatory funnel. 50 mL of diethyl ether was added and the mixture was shaken several times to remove the aqueous layer. The organic layer was washed three times with 50 mL of water and once with 50 mL of saturated saline solution. After drying with anhydrous magnesium sulfate for 30 minutes, the solvent was removed by distillation under reduced pressure. The solution obtained by adding a small amount of hexane was irradiated with ultrasound, resulting in the precipitation of a solid. This solid was collected and washed with a small amount of hexane. Upon drying under reduced pressure, 2.83 g of methyl(cyclopentadienyl)(2,7-di-tert-butylfluorenyl)(phenyl)methane was obtained as a white solid.

[0335] (iii) [Methylphenylmethylene (η) 5 -cyclopentadienyl)(η 5 Synthesis of [-2,7-di-tert-butylfluorene]zirconium dichloride

[0336] Under a nitrogen atmosphere, 1.50 g (3.36 mmol) of methyl(cyclopentadienyl)(2,7-di-tert-butylfluorenyl)(phenyl)methane, 50 mL of anhydrous toluene, and 570 μL (7.03 mmol) of THF were added sequentially to a 100 mL Schlenk tube. While cooling in an ice bath, 4.20 mL (6.93 mmol) of a 1.65 M butyllithium / hexane solution was slowly added, and the mixture was stirred at 45 °C for 5 hours. The solvent was removed by distillation under reduced pressure, and 40 mL of anhydrous diethyl ether was added to prepare 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 slowly heated to room temperature while stirring for 16 hours, resulting in an orange-red slurry. The solvent was removed by distillation under reduced pressure, and the resulting solid was transferred to a glove box, washed with hexane, and extracted with dichloromethane. After the solvent was removed by distillation under reduced pressure and the mixture was concentrated, a small amount of hexane was added, and the mixture was placed at -20°C, resulting in the precipitation of an orange-red solid. This solid was washed with a small amount of hexane and dried under reduced pressure, thus yielding [methylphenylmethylene (η-)] as an orange-red solid. 5 -cyclopentadienyl)(η 5 1.20 g of zirconium dichloride (-2,7-di-tert-butylfluorenyl)]

[0337] [Synthesis example 2]

[0338] [Ethylene(η)] 5 -cyclopentadienyl)(η 5 Synthesis of [-2,7-di-tert-butylfluorene]zirconium dichloride

[0339] [Ethylene(η)] 5 -cyclopentadienyl)(η 5 Zirconium dichloride (-2,7-di-tert-butylfluorenyl) was synthesized using the method described in Japanese Patent No. 4367687.

[0340] <Example 1 of Aggregation>

[0341] 910 mL of heptane and 50 g of propylene were added to a 2 L stainless steel autoclave that had undergone nitrogen replacement. The system was heated to 130 °C, and the total pressure was increased to 1 MPaG by supplying 0.082 MPa of hydrogen and 0.082 MPa of ethylene. Next, 0.4 mmol of triisobutylaluminum and [methylphenylmethylene (η-)] were pressurized with nitrogen. 5 -cyclopentadienyl)(η 5Polymerization was initiated by stirring at 400 rpm with 0.0006 mmol of zirconium dichloride (-2,7-di-tert-butylfluorenyl)zirconium dichloride and 0.006 mmol of N,N-dimethylaniline tetrakis(pentafluorophenyl)borate. Ethylene was then continuously supplied, maintaining a total pressure of 1 MPaG, and polymerization was carried out at 130 °C for 5 minutes. After stopping the polymerization by adding a small amount of ethanol, unreacted ethylene, propylene, and hydrogen were purged. The resulting polymer solution was washed three times with 1000 mL of 0.2 mol / L hydrochloric acid, followed by three times with 1000 mL of distilled water. After drying with magnesium sulfate, the solvent was removed by distillation under reduced pressure. After drying the obtained polymer under reduced pressure at 80°C overnight, it was further distilled using a Shinko Pantech 2-03 type thin-film distillation apparatus. The reduced pressure was maintained at 400 Pa, and the thin-film distillation was carried out at a set temperature of 180°C and a flow rate of 3.1 ml / min to obtain 26 g of ethylene-propylene copolymer.

[0342] <Example 2 of Aggregation>

[0343] 910 mL of heptane and 50 g of propylene were added to a 2 L stainless steel autoclave that had undergone nitrogen replacement. The system was heated to 130 °C, and the total pressure was increased to 1 MPaG by supplying 0.047 MPa of hydrogen and 0.085 MPa of ethylene. Next, 0.4 mmol of triisobutylaluminum and [methylphenylmethylene (η-)] were pressurized with nitrogen. 5 -cyclopentadienyl)(η 5 Polymerization was initiated by stirring at 400 rpm with 0.0006 mmol of zirconium dichloride (-2,7-di-tert-butylfluorenyl)zirconium dichloride and 0.006 mmol of N,N-dimethylaniline tetrakis(pentafluorophenyl)borate. Ethylene was then continuously supplied, maintaining a total pressure of 1 MPaG, and polymerization was carried out at 130 °C for 5 minutes. After stopping the polymerization by adding a small amount of ethanol, unreacted ethylene, propylene, and hydrogen were purged. The resulting polymer solution was washed three times with 1000 mL of 0.2 mol / L hydrochloric acid, followed by three times with 1000 mL of distilled water. After drying with magnesium sulfate, the solvent was removed by distillation under reduced pressure. After drying the obtained polymer under reduced pressure at 80°C overnight, it was further distilled using a Shinko Pantech 2-03 type thin-film distillation apparatus. The reduced pressure was maintained at 400 Pa, and the thin-film distillation was carried out at a set temperature of 180°C and a flow rate of 3.1 ml / min to obtain 26 g of ethylene-propylene copolymer.

[0344] <Example 3>

[0345] 250 mL of heptane was added to a 1 L glass polymerizer that had undergone nitrogen replacement. The system was heated to 50 °C, and then ethylene, propylene, and hydrogen were continuously fed into the polymerizer at a flow rate of 25 L / hr, 75 L / hr, and 100 L / hr, while stirring at 600 rpm. Next, 0.2 mmol of triisobutylaluminum was added to the polymerizer, followed by the reaction of 0.688 mmol of MMAO and [ethylene(η-)] in toluene. 5 -cyclopentadienyl)(η 5 The product obtained by premixing 0.00230 mmol of [-2,7-di-tert-butylfluorenyl]zirconium dichloride for more than 15 minutes was loaded into a polymerizer, thereby initiating polymerization. Then, ethylene, propylene, and hydrogen were continuously supplied, and polymerization was carried out at 50°C for 15 minutes. After stopping the polymerization by adding a small amount of isobutanol to the system, unreacted monomers were purged. The resulting polymer solution was washed three times with 100 mL of 0.2 mol / L hydrochloric acid, followed by three times with 100 mL of distilled water. After drying with magnesium sulfate, the solvent was removed by distillation under reduced pressure. The resulting polymer was dried overnight under reduced pressure at 80°C to obtain 1.43 g of ethylene-propylene copolymer. The ethylene-propylene copolymer was further subjected to the above-described hydrogenation process.

[0346] <Example 4 of Aggregation>

[0347] 250 mL of decane was added to a 1 L glass polymerizer that had undergone nitrogen replacement. The system was heated to 130 °C, and then ethylene, propylene, and hydrogen were continuously fed into the polymerizer at a flow rate of 25 L / hr, 75 L / hr, and 100 L / hr, while stirring at 600 rpm. Next, 0.2 mmol of triisobutylaluminum was added to the polymerizer, followed by the reaction of 1.213 mmol of MMAO and [methylphenylmethylene (η-)] in toluene. 5 -cyclopentadienyl)(η 5 The product obtained by premixing 0.00402 mmol of [-2,7-di-tert-butylfluorenyl]zirconium dichloride for more than 15 minutes was loaded into a polymerizer, thereby initiating polymerization. Then, ethylene, propylene, and hydrogen were continuously supplied, and polymerization was carried out at 130°C for 15 minutes. After stopping the polymerization by adding a small amount of isobutanol to the system, unreacted monomers were purged. The resulting polymer solution was washed three times with 100 mL of 0.2 mol / L hydrochloric acid, followed by three times with 100 mL of distilled water. After drying with magnesium sulfate, the solvent was removed by distillation under reduced pressure. The resulting polymer was dried overnight under reduced pressure at 80°C to obtain 0.77 g of ethylene-propylene copolymer. The ethylene-propylene copolymer was further subjected to the above-described hydrogenation process.

[0348] <Example 5>

[0349] One liter of dehydrated and purified hexane was loaded into a 2-liter continuous polymerizer with stirring blades that had undergone sufficient nitrogen replacement. Ethyl sesquichloride (Al(C2H5)) adjusted to 96 mmol / L was continuously supplied at a rate of 500 ml / h. 1.5 ·Cl 1.5 The polymer was first fed a hexane solution for 1 hour, and then a hexane solution of VO(OC2H5)Cl2, adjusted to 16 mmol / L, was continuously supplied as a catalyst at a rate of 500 ml / h. Meanwhile, the polymerization liquid was continuously withdrawn from the top of the polymerizer, ensuring that the polymer liquid volume in the polymerizer remained at 1 liter at all times. Next, ethylene gas, propylene gas, and hydrogen gas were supplied at a rate of 38 L / h and 3 L / h respectively, using a bubble tube. The copolymerization reaction was carried out at 35°C by circulating the refrigerant in a jacket installed outside the polymerizer.

[0350] The polymerization solution containing the ethylene-propylene copolymer obtained under the above conditions was washed three times with 100 mL of 0.2 mol / L hydrochloric acid, followed by three washes with 100 mL of distilled water. After drying with magnesium sulfate, the solvent was removed by distillation under reduced pressure. The resulting polymer was dried overnight under reduced pressure at 130 °C. The obtained ethylene-propylene copolymer had an ethylene content of 53.0 mol%, a rotational viscosity of 3,100 mPa·s at 150 °C, a Mw of 24,000, a Mw / Mn ratio of 2.1, a B value of 1.2, a chlorine content of 18 ppm, and no observed melting point (melting peak).

[0351] <Example 6>

[0352] One liter of dehydrated and purified hexane was loaded into a 2-liter continuous polymerizer with stirring blades that had undergone sufficient nitrogen replacement. Ethyl sesquichloride (Al(C2H5)) adjusted to 96 mmol / L was continuously supplied at a rate of 500 ml / h. 1.5 ·Cl 1.5 The polymer was first fed a hexane solution for 1 hour, and then a hexane solution of VO(OC2H5)Cl2, adjusted to 16 mmol / L, was continuously supplied as a catalyst at a rate of 500 ml / h. Meanwhile, the polymerization liquid was continuously withdrawn from the top of the polymerizer, ensuring that the polymer liquid volume in the polymerizer remained at 1 liter at all times. Next, ethylene gas, propylene gas, and hydrogen gas were supplied at a rate of 47 L / h and 20 L / h respectively using a bubble tube. The copolymerization reaction was carried out at 35°C by circulating the refrigerant in a jacket installed outside the polymerizer.

[0353] The polymerization solution containing the ethylene-propylene copolymer obtained under the above conditions was washed three times with 100 mL of 0.2 mol / L hydrochloric acid, followed by three washes with 100 mL of distilled water. After drying with magnesium sulfate, the solvent was removed by distillation under reduced pressure. The resulting polymer was dried overnight under reduced pressure at 130 °C. The obtained ethylene-propylene copolymer had an ethylene content of 54.9 mol%, a rotational viscosity of 260 mPa·s at 150 °C, a Mw of 14,000, a Mw / Mn ratio of 2.0, a B value of 1.2, a chlorine content of 20 ppm, and no observed melting point (melting peak).

[0354] The polymers obtained in polymerization examples 1 to 4 (for polymerization examples 3 and 4, they were hydrogenated polymers) were designated as polymers 1 to 4, respectively. The physical properties and solubility in mineral oil of polymers 1 to 4, as well as polymethyl methacrylate (PMA), polybutene (PIB), and olefin copolymer (OCP), are shown in Table 2. Furthermore, the metering accuracy for the liquid polymers (excluding OCP, which is a solid) used in the formulation was evaluated and is also shown in Table 2. The PMA, PIB, OCP, and mineral oil used are described below.

[0355] Polymethyl methacrylate (PMA); polymethyl methacrylate (Viscoplex 0-220 manufactured by Evonik) with a weight-average molecular weight of 41,800 as determined by GPC, similar to ethylene-α-olefin copolymers.

[0356] Polybutene (PIB); similar to ethylene-α-olefin copolymers, high molecular weight liquid polybutene (JX Nippon Oil & Energy Corporation's HV-1900) with a weight-average molecular weight of 8,400 and a molecular weight distribution of 2.6, as determined by GPC.

[0357] Olefin copolymer (OCP); a solid olefin copolymer (PARATONE 8900 manufactured by ExxonMobil Chemical) with a weight-average molecular weight of 155,000 and a molecular weight distribution of 2.1, as determined by GPC in the same manner as ethylene-α-olefin copolymer.

[0358] (A) Mineral oil; Mineral oil 1 (dynamic viscosity at 40℃: 19.3 mm) 2 / s, viscosity index: 126, pour point: -15℃ API (American Petroleum Institute) Group III mineral oil (SK Lubricants Yubase-4)

[0359] [Table 2]

[0360]

[0361] When formulating the lubricating oil composition, the metering accuracy and solubility in (A) mineral oil were evaluated as described above. For polymers 1 to 3, there was no dripping from the gear pump during metering at 80°C, and they dissolved without problems within approximately 30 minutes to 1 hour. However, for polymers 4, PMA, and PIB, polymer continued to drip from the front of the discharge port when metering with the gear pump stopped, resulting in errors relative to the specified filling amount. Furthermore, for OCP, it remained undissolved after 3 hours at 80°C.

[0362] [Preparation of Lubricating Oil Compositions for Working Oils]

[0363] In preparing the lubricating oil composition for working oil, in addition to the above-mentioned (C) ethylene-α-olefin copolymer, PMA, PIB, and (A) mineral oil, the following substances are also used.

[0364] Pour point depressant; Irgaflow 720P manufactured by BASF

[0365] (B) Synthetic oil; Synthetic oil 1 (40℃ dynamic viscosity: 17.7 mm) 2 / s, viscosity index: 123, pour point: below -60℃ (API (American Petroleum Institute) group IV polyalphaolefin (Chevron Phillips Chemical Synfluid PAO-4))

[0366] <Lubricating Oil Compositions for Working Oils>

[0367] [Example 1]

[0368] A lubricating oil composition was prepared by using mineral oil 1 and polymer 1, which is a (C) ethylene-α-olefin copolymer, in a manner that combines them with a pour point depressant to a total of 100% by mass, to form a working oil lubricating oil composition with a viscosity equivalent to ISO 46. The amounts of each component added and the physical properties of the lubricating oil composition are shown in Table 3.

[0369] [Example 2]

[0370] Polymer 1 was replaced with polymer 2 at the amount shown in Table 3, and the amount of mineral oil 1 was adjusted. Otherwise, the lubricating oil composition was prepared in the same manner as in Example 1. The physical properties of the lubricating oil composition are shown in Table 3.

[0371] [Reference Example 1]

[0372] Polymer 1 was replaced with polymer 3 as described in Table 2 at the amount shown in Table 3, and the amount of mineral oil 1 was adjusted. Otherwise, the lubricating oil composition was prepared in the same manner as in Example 1. The physical properties of the lubricating oil composition are shown in Table 3.

[0373] [Comparative Example 1]

[0374] Polymer 1 was replaced with polymethyl methacrylate (PMA) at the amounts described in Table 3, and the amount of mineral oil 1 was adjusted. Otherwise, the lubricating oil composition was prepared in the same manner as in Example 1. The physical properties of the lubricating oil composition are shown in Table 3.

[0375] [Comparative Example 2]

[0376] Polymer 1 was replaced with polymer 4 as described in Table 2 at the amount shown in Table 3, and the amount of mineral oil 1 was adjusted. Otherwise, the lubricating oil composition was prepared in the same manner as in Example 1. The physical properties of the lubricating oil composition are shown in Table 3.

[0377] [Comparative Example 3]

[0378] Polymer 1 was replaced with polybutene (PIB) at the amounts described in Table 3, and the amount of mineral oil 1 was adjusted. Otherwise, the lubricating oil composition was prepared in the same manner as in Example 1. The physical properties of the lubricating oil composition are shown in Table 3.

[0379] [Example 3]

[0380] Mineral oil 1 was replaced with synthetic oil 1 at the amounts shown in Table 3, and the amount of polymer 2 was adjusted. Otherwise, a lubricating oil composition was prepared in the same manner as in Example 2. The physical properties of the lubricating oil composition are shown in Table 3.

[0381] [Table 3]

[0382]

[0383] As a working oil lubricating oil composition using (A) mineral oil in the lubricating oil base, when comparing Examples 1 and 2 containing (C) ethylene-α-olefin copolymer with Comparative Example 1 containing PMA instead of (C) ethylene-α-olefin copolymer, the dynamic viscosity at 40°C after shear test in Examples 1 and 2 remained 40 mm higher than that in Comparative Example 1. 2With a viscosity of / s or higher, the working oil lubricating oil composition of this application can maintain its performance as a working oil for a longer period of time, continuously protecting the working mechanism. Furthermore, Comparative Example 2, which uses polymer 4, has low metering accuracy, making it very difficult to obtain a lubricating oil composition industrially. On the other hand, Comparative Example 3, which contains PIB instead of (C) ethylene-α-olefin copolymer, when formulated in an ISO 46 manner, has a dynamic viscosity of less than 8 mm at 100°C. 2 When the working mechanism is used continuously and the oil temperature rises, the oil film strength on the metal sliding surfaces within the working mechanism using the working oil lubricant composition is low, resulting in oil film breakage and metal-to-metal contact. As a result, there is a concern about wear on the sliding surfaces. In addition, the fluidity is significantly reduced at low temperatures, making it unsuitable for use in low-temperature environments.

Claims

1. A lubricating oil composition for use in applications where the composition contains a lubricating oil base oil in a proportion of 93-99% by mass and a lubricating oil viscosity modifier in a proportion of 1-7% by mass, wherein... The total amount of the lubricating oil base oil and the lubricating oil viscosity modifier is set at 100% by mass. The lubricating oil base oil is formed from (A) mineral oil having the characteristics of (A1) to (A3) and / or (B) synthetic oil having the characteristics of (B1) to (B3). The lubricating oil viscosity modifier is formed from (C) ethylene-α-olefin copolymer having the characteristics of (C1) to (C5) and (C6). The dynamic viscosity of the working oil lubricating oil composition at 40°C is 28 to 170 mm. 2 / s, (A1) The dynamic viscosity at 40℃ is 10~100 mm. 2 / s; (A2) Viscosity index is above 90; (A3) Pour point is below 0°C; (B1) The dynamic viscosity at 40℃ is 4~100 mm. 2 / s; (B2) Viscosity index is above 90; (B3) Pour point is below -30℃; (C1) The molar content of ethylene is in the range of 30~70 mol%; (C2) The rotational viscosity at 150℃ is 300~8,000 mPa·s; (C3) Hassen chromaticity is below 30; (C4) Among the molecular weights determined by gel permeation chromatography (GPC) and converted to polystyrene, the molecular weight distribution (Mw / Mn) is less than 2.5; (C5) The value of B, as expressed by the following formula [1], is 1.1 or higher. [Mathematical Expression 1] In formula [1], P E P represents the mole fraction of ethylene. O P represents the molar fraction of α-olefin components. OE This represents the mole fraction of the ethylene-α-olefin chain in the entire binary chain; (C6) The weight-average molecular weight (Mw) determined by gel permeation chromatography (GPC) and converted to polystyrene is 15,000 to 50,000.

2. The lubricating oil composition for working oil as described in claim 1, wherein, The (C) ethylene-α-olefin copolymer satisfies the condition that the weight-average molecular weight (Mw) determined by gel permeation chromatography (GPC) and converted to polystyrene is 15,000 to 40,000.

3. The lubricating oil composition for working oil as described in claim 1 or 2, wherein, The ethylene molar content of the (C) ethylene-α-olefin copolymer is in the range of 40~60 mol%.

4. The lubricating oil composition for working oil as described in claim 1 or 2, wherein, The rotational viscosity of the (C) ethylene-α-olefin copolymer at 150°C is 1,000~5,000 mPa·s.

5. The lubricating oil composition for working oil as described in claim 1 or 2, wherein, The α-olefin of the (C) ethylene-α-olefin copolymer is propylene.

6. A hydraulic working oil for use in machine tools, molding machines or construction machinery, which is formed from the working oil lubricating oil composition according to any one of claims 1 to 5.

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