​PROBLEM TO BE SOLVED: to provide a golf ball excellent in temperature viscosity characteristics and low-temperature viscosity characteristics, and to provide a lubricating oil composition having extremely excellent shear stability
​Background
[0002]
​A lubricating oil such as a gear oil, a transmission oil, a working oil, a grease, etc., in addition to performance such as protection and heat dissipation of an internal combustion engine and a machine tool, abrasion resistance, heat resistance, sludge resistance, and lubricating oil consumption characteristics, various performances such as fuel economy are required. In addition, in recent years, high performance and high output of an internal combustion engine and an industrial machine to be used are achieved, the demand performance is becoming more sophisticated in accordance with the severity of the operating conditions ​PROBLEM TO BE SOLVED: to solve the problem that the use environment of lubricating oil is particularly severe in recent years, there is a tendency that a long service life is required in consideration of environmental problems, and the heat resistance is improved, in addition to improvement of oxidation stability, low viscosity caused by shear stress from an engine and a machine is suppressed, that is, it is required to improve the shear stability of the lubricating oil. On the other hand, the energy conversion efficiency of the engine is improved, in order to secure good lubricity of the engine in an extremely low temperature environment, the oil film of the lubricating oil is held at a high temperature, and a temperature viscosity characteristic of maintaining flowability at a low temperature is important ​The temperature viscosity characteristics described herein are used as one index, the numerical value can be quantified by the viscosity index calculated by the method described in JIS k2283, a lubricating oil having a higher viscosity index has a higher temperature viscosity characteristic
[0003]
​Therefore, the lubricating oil has excellent heat resistance, oxidation stability and shear stability, and a material having good temperature viscosity characteristics is required
[0004]
​Especially, there is provided a lubricating oil used in an automobile, a driving oil represented by a gear oil for an automobile such as a differential gear oil and a transmission oil, high flowability at extremely low temperatures such as -40° c, that is, excellent low-temperature viscosity characteristics have been required. These viscosity characteristics are directly connected to fuel economy performance of an automobile, in the performance improvement request, a kyoto chairman is adopted in 1997 and thereafter, in recent years, carbon dioxide emission regulation and fuel consumption regulation for a passenger car are provided by the government of each country in the world, or a future goal is determined
[0005]
​On the basis of this, in order to achieve a fuel consumption target and to improve fuel consumption, each part of the passenger car engine is miniaturized, the amount of lubricating oil used is also reduced. Therefore, the load applied to the lubricating oil has increased, a longer service life of the lubricating oil has been demanded ​The gear oil for automobile or the transmission oil is subjected to a shear stress from a gear or a metal belt or the like, the viscosity of the lubricating oil is lowered by cutting the molecules of the base material used in the lubricating oil along with the passage of use. When the lubricating oil viscosity is lowered, gears are brought into contact with each other, and significant damage is imparted to the gear. The viscosity (initial viscosity) at the time of production of the lubricating oil is estimated by predicting the decrease in the viscosity of the lubricating oil in advance therefore,) on the basis of the result of the determination, and it is necessary to provide the lubricating oil after deterioration accompanying the use so that ideal lubrication can be performed ​J306, which is the viscosity standard of automobile gear oils by scando of automation engineers (SAE), a shear test (method C, 20 hours) defined by CRC l-45-t -93) and the following minimum viscosity is determined
​Of course, the shear stability of the base material used in the lubricating oil is excellent, the life of the lubricating oil can be extended, it is not necessary to increase the initial viscosity of the lubricating oil, the stirring resistance of the lubricating oil to the result gear can be lowered, so that the fuel consumption can be improved
[0007]
​Further, the temperature viscosity characteristic, that is, the temperature dependency of the lubricating oil viscosity is low, the viscosity increase of the lubricating oil is suppressed even in a low-temperature environment, the gear resistance due to the lubricating oil becomes relatively lower than that of the conventional technique, and the fuel consumption can be improved
​PROBLEM TO BE SOLVED: to provide a differential gear oil, or the viscosity of the transmission oil is lowered as compared with the conventional one, a reduction in the stirring resistance due to the lubricating oil is realized, there is an increasing risk of metal contact in gears, a material having extremely high shear stability which does not cause a decrease in viscosity is required
​Based on the performance improvement request, a CRC l-45-t -93 shear test carried out at a test time of 20 hours, even at a test time of 100 hours corresponding to a normal five times, the same, the minimum viscosity after the test is defined for each driving oil, so that it is required to maintain this
[0008]
​Lubricating oil base oil satisfying the above-mentioned requirement, a poly-alpha-olefin (PAO) which is a synthetic lubricating oil) is widely used in a wide industrial scale. Such PAO is disclosed in patent documents 1-3 and the like, a higher alpha-olefin can be obtained by oligomerization of a higher alpha-olefin by an acid catalyst
[0009]
​On the other hand, patent document (4) the ethylene-alpha-olefin copolymer is also similar to the PAO as described above, oxidation stability and shear stability, and can be used as a synthetic lubricating oil having excellent heat resistance ​PROBLEM TO BE SOLVED: to provide a method for producing an ethylene-alpha-olefin copolymer used as a synthetic lubricating oil, patent document 5 and patent document (6) a vanadium compound and an organoaluminum compound as described above as a result, in particular, an ethylene-propylene copolymer is mainly used
[0011]
​A method for producing a copolymer by a high polymerization activity is disclosed in patent document 7 and patent document (8); a metallocene compound such as zirconium oxide as described above; and an organoaluminum oxy compound (aluminoxane); and a method of using a catalyst system comprising (9); and a method for producing a synthetic lubricating oil comprising an ethylene-alpha-olefin copolymer obtained by using a catalyst system in which a specific metallocene catalyst and an aluminoxane are combined
[0012]
​Recently, low-temperature viscosity characteristics and heat resistance. There is a tendency that a demand for a PAO or an ethylene-propylene copolymer or the like which is a synthetic lubricating oil base material excellent in oxidation stability tends to increase, from the viewpoint of energy saving and energy saving, the viscosity index, there is a demand for further improvement of low-temperature viscosity characteristics
[0013]
​On the basis of this request, patent document (10~13) a metallocene compound such as zirconia as described in # t and an organoaluminum oxy compound (aluminoxane); and a method of using a catalyst system comprising
[0014]
​However, the shear stability of the lubricating oil composition is conventionally known, it is known that the molecular weight of the component contained is dependent on the molecular weight of the component contained. That is, the molecular weight of the present invention a lubricating oil composition containing a high component tends to cause a decrease in viscosity due to shear stress, and the viscosity reduction rate is correlated to the molecular weight of the content component
[0015]
​On the other hand, the lubricating oil composition of the present invention the temperature viscosity characteristic and the low temperature viscosity characteristic are improved by containing a higher molecular weight component. That is, a PAO or an ethylene-propylene copolymer used for the lubricating oil composition is provided, the temperature viscosity characteristic is improved as the molecular weight increases, so that the shear stability is deteriorated. For this point, there is room for improvement from the viewpoint of achieving both shear stability and temperature viscosity characteristics 0016]
​Patent document 1: US pat. no. 3,780, 128
​US pat. no. 4,032,591
​Patent document 3: JP-a-1-163136
​Patent document 4: japanese laid-open patent publication no. 57-117595
​Patent document 5: japanese patent publication no. 2-61163
​Patent document 6: japanese patent publication no. 2-7998
​Patent document 7: JP-a-61-221207
​Patent document 8: japanese patent publication no. 7-121969
​Patent document 9: japanese patent no. 2796376
​Patent document 10: japanese patent application laid-open no. 2001-335607
​Patent document 11: japanese patent application laid-open no. 2004-506758
​Patent document 12: japanese patent application laid-open no. 2009-503147
​Patent document 13: japanese patent application laid-open no. 2009-514991
​Summary of the invention
​Problem to be solved by the invention
[0017]
​To solve the problem of such a conventional technique, to save fuel consumption and energy saving of an automobile and an industrial machine, to provide a lubricating oil having extremely excellent shear stability and low-temperature viscosity characteristics
​Means for solving the problem
[0018]
​The inventors have earnestly studied to develop a lubricating oil composition having excellent performance, a specific lubricating oil base oil and a specific alpha-olefin (co) a lubricating oil composition containing a polymer and satisfying a specific condition, the problem can be solved, and the present invention has been accomplished
[0019]
​The present inventors are described in CRC l-45-t -93 of the present invention a shear test in which the test time is 100 hours in accordance with the method, high shear stability and temperature viscosity characteristics by optimizing the lubricating oil composition based on the fact that a specific molecular weight region of the lubricating oil composition is affected, the present invention is directed to a lubricating oil composition having low-temperature viscosity characteristics specifically, the following aspects can be cited
[0020]
​SOLUTION: (A) a kinematic viscosity at 100°c is 1-10 mm2／ s; and (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-() contains an ethylene-alpha-olefin copolymer having
​The kinematic viscosity at 100°c is 20 mm2／ s or less,
​SOLUTION: a gel permeation chromatography (GPC) has a peak top in a range of a molecular weight of 3,000-10,000 obtained by standard polystyrene conversion,
​A component having a molecular weight higher than a molecular weight giving the peak top is provided, a molecular weight of 20, and the weight fraction of the component of at least 000 is 1-10%
​(B1) a molecular weight measured by gel permeation chromatography (GPC), and a peak top molecular weight obtained by standard polystyrene conversion is 3,000 to 10,000
​(B2) there is no melting peak by a differential thermal calorimeter (DSC)
​(B3) the following expression [ 1 ]
​In the formula, PE represents a content mole fraction of an ethylene component, PO represents the content mole fraction of the alpha-olefin component, POE represents the molar fraction of the ethylene-alpha-olefin chain of the whole DYAD chain. SOLUTION:
​The b value expressed by the expression (1) is 1.1 or more
​(B4) kinematic viscosity at 100°c is 140-500 mm2／ s
[0023]
​[ 2 ] Ethylene-alpha-olefin copolymer (b) in the lubricating oil composition of item [ 1 ], wherein the ethylene mole content of the lubricating oil is in the range of 30 to 70 mol %
​[ 3 ] The ethylene-alpha-olefin copolymer (b) alpha-olefin is propylene
​[ 4 ] Lubricating oil composition for automobile. The lubricating oil composition according to any one of items [ 1 ] to [ 3 ]
​[ 5 ] The kinematic viscosity at 100°c is 7.5 mm2／ s or less. [ 4 ] A transmission oil for an automobile comprising the lubricating oil composition as described in [ 4 ]
​Effects of the invention
[0024]
​SOLUTION: the lubricating oil composition of the present invention comprises, excellent shear stability and high temperature viscosity characteristics compared with conventional lubricating oils, further, there is provided a lubricating oil composition having excellent low-temperature viscosity characteristics, lubricating oil for automobile, transmission oil for automobile, and gear oil for automobile, and can be suitably applied to a low-viscosity transmission oil for an automobile
​Simple description of drawings
[0025]
​[ FIG. 1 ] prior to shear test of lubricating oil composition in example 2 and comparative example 3 (solid line)) and a GPC chart in a shear test (broken line)
​FIG. 2 is an enlarged view of a molecular weight of 10,000 or less in the GPC chart of FIG. 1;
​System for carrying out the invention
[0026]
​The lubricating oil composition according to the present invention is described in detail below
​&T; (a) lubricating base oil & gtg;
​The lubricating oil base oil (A) has a kinematic viscosity at 100°c of 1-10 mm2／ is not particularly limited except that it is s, a mineral oil-based lubricating oil base oil and/or a synthetic lubricating oil base oil (hereinafter also referred to as "synthetic hydrocarbon oil") used for ordinary lubricating oil. A map is used
[0027]
​There are several grades of mineral oil-based lubricating oil base oils depending on how to purify the oil-based lubricating base oil specifically, a lubricating oil fraction obtained by subjecting the normal pressure residual oil obtained by subjecting the crude oil to normal pressure distillation is subjected to a reduced pressure distillation, solvent extraction, hydrocracking, solvent dewaxing, and purification is carried out by performing one or more treatments such as hydrogenation purification, and a lubricant base oil such as a wax isomerized mineral oil can be exemplified
​In addition. SOLUTION: a gas. PROBLEM TO BE SOLVED: to provide. SOLUTION: a liquid (GTL)) a base oil is also preferably used. Such GTL base oils include, for example, EP 077659, EP 0668342, WO 97／ 21788, WO 00／ 15736, WO 00／ 14188, WO 00／ 14187, WO 00／ 14183 and WO 00／ 14179, WO 00／ 8115, WO 99／ 41332, EP 1029029, and WO 01／ 18156 and WO01／ 57166 ​Examples of the synthetic hydrocarbon oils include alpha-olefin oligomers, alkylbenzenes, and alkylnaphthalenes, isobutene oligomer or hydrides thereof, paraffins, polyoxyalkylene glycols, dialkyldiphenyl ethers, polyphenyl ethers, fatty acid esters and the like
[0029]
​The alpha-olefin oligomer is selected from the group consisting of a carbon atom number (8~12) and a low molecular weight oligomer (ethylene-alpha-olefin copolymer) of at least one olefin selected from the olefins (b) except for the following) can be used. SOLUTION: when an alpha-olefin oligomer is used in the lubricating oil composition of the present invention, a lubricating oil composition excellent in low-temperature viscosity characteristics and heat resistance is obtained. The alpha-olefin oligomer is a ziegler catalyst and a cationic polymerization using a lewis acid as a catalyst, thermal polymerization and radical polymerization ​PROBLEM TO BE SOLVED: to provide a golf ball which is industrially available and has a kinematic viscosity of 100°c (2 mm2)／ s -100 mm2／ s is commercially available. For example, nextbase, manufactured by nestec co. ltd. SPECTRASYN from exxonmobil chemical co. ltd. is used, ltd.), and synfluid such as DURASYN, chevron phillips chemical co. ltd. manufactured by INSURGOMERS co. ltd.
[0030]
​Most of the alkylbenzenes and alkylnaphthalenes are dialkyl benzene or dialkylnaphthalene having a normal alkyl chain length of 6 to 14 carbon atoms, such alkylbenzenes or alkylnaphthalenes include, benzene or a free lean alkylation reaction of naphthalene with an olefin. The alkylated olefins used in the production of alkylbenzenes or alkylnaphthalenes are provided, linear or branched olefins, or combinations thereof. These manufacturing methods are described, for example, in US pat. no. 3,909,432
[0031]
​The fatty acid ester is not particularly limited, and includes the following carbon, and a fatty acid ester composed of only oxygen and hydrogen
[0032]
​A monoester produced from a monobasic acid and an alcohol; a dibasic acid and an alcohol, or a diester produced from a diol and a monobasic acid or an acid mixture; a diol and a triol () trimethylolpropane), tetraol (eg, pentaerythritol), hexaol (eg, dipentaerythritol) or the like; and a polyol ester produced by reacting the same with a monobasic acid or an acid mixture ​Examples of these esters include ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, tridecyl pelargonate, di-2-ethylhexyl adipate, di-2-ethylhexyl azelate, trimethylolpropane caprylate, trimethylolpropane pelargonate, trimethylolpropane triheptanoate, pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate ​, Pentaerythritol tetraheptanoate and the like are listed as esters
[0033]
​Specifically, from the viewpoint of compatibility with a copolymer (B) to be described later, the alcohol moiety constituting the ester is preferably an alcohol having a hydroxyl group of two or more functional groups, the fatty acid site is preferably a fatty acid having 8 or more carbon atoms. However, in terms of production costs for fatty acids, an industrially available fatty acid having a carbon number of 20 or less is predominant. The fatty acid constituting the ester may be one or more acid mixtures, the performance of the present invention is sufficiently exhibited ​More specifically, the ester is more specifically, trimethylolpropane lauric acid stearate mixed tri ester, diisodecyl adipate, etc. and these are copolymers (b) and a saturated hydrocarbon component such as the above-mentioned saturated hydrocarbon component, an antioxidant, a corrosion inhibitor, and a wear-resistant agent having a polar group to be described later, friction modifier and pour point depressant, from the viewpoint of compatibility with a stabilizer such as a rust inhibitor and a defoaming agent
[0034]
​The lubricating oil composition uses a synthetic hydrocarbon oil as a lubricating base oil (A), when the whole of the lubricating oil composition is 100 mass %, the fatty acid ester is preferably contained in an amount of 5-20 mass %. SOLUTION: various internal combustion engine, good compatibility can be obtained with respect to a lubricant sealing material such as a resin and an elastomer in an industrial machine. Specifically, the swelling of the lubricating oil sealing material can be suppressed. From the viewpoint of oxidation stability or heat resistance, the amount of the ester is preferably 20 mass % or less ​The lubricating oil composition includes mineral oil, the mineral oil itself has a swelling suppressing effect of the lubricating oil sealing material, the fatty acid ester is not necessarily required
[0035]
​SOLUTION: in the lubricating oil composition of the present invention, (a) and a mineral oil-based lubricating oil base oil or a synthetic lubricating oil base oil may be used singly or in combination, a mineral oil-based lubricant base oil, and any mixture of two or more kinds of lubricating oils selected from among synthetic lubricating oil base oils may be used
​Lubricating oil base oil (a) the kinematic viscosity at 100°c is 1-10 mm2 when measured according to the method described in JIS k2283／ s, preferably 2 to 7 mm2／ s. when the viscosity is higher than this, the temperature viscosity characteristics of the lubricating oil composition are inferior, an evaporation loss at a high temperature of the lubricating oil composition is increased when the viscosity is low .

​Claim
​[ Claim 1 ]
​SOLUTION: (A) a kinematic viscosity at 100°c is 1-10 mm2／ s; and (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-(b4): (b1)-() contains an ethylene-alpha-olefin copolymer having
​The kinematic viscosity at 100°c is 20 mm2／ s or less,
​SOLUTION: a gel permeation chromatography (GPC) has a peak top in a range of 3,000 to 10,000 molecular weight obtained by standard polystyrene conversion,
​A component having a molecular weight higher than a molecular weight giving the peak top is provided, a molecular weight of 20, and the weight fraction of the component of at least 000 is 1-10%
​(B1) a molecular weight measured by gel permeation chromatography (GPC), and a peak top molecular weight obtained by standard polystyrene conversion is 3,000 to 10,000
​(B2) there is no melting peak by a differential thermal calorimeter (DSC)
​(B3) the following expression [ 1 ]
​(NB)

​In the formula, PE represents a content mole fraction of an ethylene component, PO represents the content mole fraction of the alpha-olefin component, POE represents the molar fraction of the ethylene-alpha-olefin chain of the whole DYAD chain. SOLUTION:
​The b value expressed by the expression (1) is 1.1 or more
​(B4) kinematic viscosity at 100°c is 140-500 mm2／ s
​[ Claim 2 ]
​Ethylene-alpha-olefin copolymer (b) in the lubricating oil composition is in a range of 30 to 70 mol %
​[ Claim 3 ]
​The alpha-olefin of the ethylene-alpha-olefin copolymer (B) is propylene (1) the lubricating oil composition of claim 2
​[ Claim 4 ]
​The lubricating oil composition according to any one of claims 1 to 3, which is a lubricating oil composition for automobile
​[ Claim 5 ]
​A 100°c kinematic viscosity is 7.5 mm2／ s or less