CN1136074A - Lubricant oil composition and lubricant grease composition - Google Patents

Abstract

The present invention provides a lubricating oil composition and a lubricating grease composition which greatly improves thermal oxidation stability and can be used under high-speed, high-temperature, and high-load conditions. It is prepared by adding polyol ester oil and alkyl phenyl ether oil in a base oil with a weight ratio of 80:20 to 20:80 and adding a mixed antioxidant accounting for 0.2 to 8% by weight of the total weight of the lubricating oil composition. The lubricating oil composition, the mixed antioxidant is formed by (A) dialkyl dithiocarbamate compound and (B) aromatic amine compound in a weight ratio of 90:10 to 10:90, And adding 0.2-8% by weight of the grease composition to the total weight of the grease composition, the composition uses lithium soap, lithium complex soap and diurea compound as thickeners.

Description

Lubricating oil composition and grease composition

The present invention relates to a lubricating oil composition and a lubricating grease composition used for lubricating bearings and the like.

The life of rolling bearings is largely affected by the lubricating properties of the lubricating oil and grease used. In the past, in addition to mineral oil as the base oil, synthetic oils such as diester oil, polyol ester oil, poly-α-alkene oil, polyphenylene ether oil, etc. were used in the lubricating oil for rolling bearings. Additives such as antioxidants such as amines and phenols to improve the properties of lubricating oils, rust inhibitors, and extreme pressure lubricating oil additives depending on the application are used. In grease, in addition to metal soaps such as lithium soap and lithium complex soap as thickeners; urea compounds such as diurea, mineral oil as base oil, diester oil, polyol ester oil, poly-alpha -Synthetic oils such as olefin oils and polyphenylene ether oils, and additives such as amines, phenols, and other antioxidants and rust inhibitors to improve the properties of lubricating oils, and additives such as extreme pressure lubricating oil additives that are used in combination according to the application . In particular, antioxidants are additives necessary to improve the thermal stability of lubricating oils and greases, and are added to almost all lubricating oils and greases. Specifically, amine antioxidants typified by phenyl-α-naphthylamine, phenolic antioxidants typified by 4,4-methylenebis(2,6-di-tert-butylphenol), and the like are used. The effect of adding anti-oxidant and anti-rust agent, in addition to the type of thickener and base oil, also varies greatly according to the rolling bearing material, rolling bearing type, bearing size, operating temperature, environment and other conditions.

In recent years, as various rotating machines have become smaller, lighter, and faster, lubricating oil and grease are often used at high temperatures. It is used under severe conditions such as high load and high speed, and there is a strong desire to eliminate maintenance, so it is desired to develop high-performance lubricating oils and greases with better thermal oxidation stability.

Therefore, the environment in which lubricating oils and greases are used is severe, and the conventional lubricating oils and greases are not satisfactory in terms of thermo-oxidative stability and maintenance-free. Once the grease is oxidized and deteriorated, the dropping point, shear stability, consistency, oil separation characteristics and other characteristics will change greatly, and the grease will leak from the bearing, greatly reducing the lubrication life. Moreover, once the base oil that plays a major role in lubrication is oxidized and deteriorated, not only the oil content will decrease due to the increase in evaporation, and the lubricating function will be lost due to the formation of sludge and viscosity increase, but also the organic acids generated due to oxidation and degradation will cause bearing damage corrosion. Oxidation degradation of lubricating oil is also the same as that of base oil of grease. Therefore, in order to prolong the life of lubricating oil and grease, it is important to suppress the oxidative deterioration of lubricating oil and grease. In addition, grease does not soften even if it is oxidized and deteriorated, grease itself does not leak from the bearing, grease maintains an appropriate fluidity in the bearing, and base oil can be sufficiently supplied to the lubricating parts of the bearing. As an example of lubricating oil, JP-A-1-259097 discloses a grease in which a diurea compound whose terminal group is primarily an aromatic group is used as a thickener and an alkyl diphenyl ether oil is used as a base oil. However, the lubricant using the diurea compound as a thickener tends to solidify, and the fluidity of the grease in the bearing deteriorates, thereby causing insufficient flow of the grease to the lubricated part in the large-diameter bearing. In order to improve the fluidity and rust resistance of grease, Japanese Patent Application Laid-Open No. 5-98280 discloses base oils and aromatic oils that contain alkyl diphenyl ether oil as an essential component and have a kinematic viscosity of 90 to 160 mm ² /S at 40°C. A lubricating grease composition composed of a diurea compound having a ratio of 70 to 95 mol% of hydrocarbon end groups as a thickener, and an organic sulfonate, nitrite, and HLB compounded as an antirust additive in the lubricating oil composition It is the grease of non-ionic surfactant of 1.5-9. In JP-A-5-140576, a mixture of poly-α-alkene oil and alkyl diphenyl ether oil is disclosed for improving high-temperature durability and low-temperature start-up, producing abnormal noise and rust resistance. A barium sulfonate grease formulated with aliphatic diurea compounds and antirust additives. JP-A-63-162791 and JP-A-586392 disclose that lithium soap greases improve the oxidation resistance and life characteristics at high temperatures. However, in large-diameter bearings, due to insufficient flow of grease to the lubrication part of the bearing and insufficient supply of base oil, the bearing heats up early and sticks, so maintenance-free is not yet sufficiently achieved.

The object of the present invention is to provide a bearing with good supply property of base oil to the lubricating part even in a large-diameter bearing, excellent oil film formation ability, low evaporation loss, excellent resistance to oxidation deterioration, and long-term bearing performance. Maintenance-free lubricating oil composition and grease composition.

In order to achieve the above object, diligent research has been carried out repeatedly, and as a result, it has been found that a lubricating oil composition and a grease composition containing a specific antioxidant in a specific ratio in the base oil have excellent thermo-oxidative stability and are suitable for use in high-speed, The lubricating life of bearings used under high temperature and high load conditions is also greatly extended compared with the prior art, thus completing the present invention.

That is, the present invention relates to a lubricating oil composition characterized in that, in the lubricating oil composition containing a base oil and an additive, a mixed antioxidant is contained in an amount of 0.2 to 8% by weight of the total amount of the lubricating oil composition, and the mixed The antioxidant is prepared by blending (A) a dialkyl dithiocarbamate compound and (B) an aromatic amine compound as an antioxidant in a weight ratio of 90-10:10-90.

Moreover, it relates to a grease composition, which is characterized in that, in the grease composition containing base oil and any thickener in lithium soap, lithium complex soap, and diurea compound, containing 0.2 to 8% by weight of a mixed antioxidant, the mixed antioxidant is (A) a dialkyl dithiocarbamate compound and (B) an aromatic amine compound as an antioxidant in a ratio of 90 to 10:10 to 90% by weight.

Moreover, it relates to a grease composition, characterized in that the base oil is a mixture of polyol ester oil and alkyl phenyl ether oil, thickened in any of lithium soap, lithium complex soap, and diurea compound The lubricating grease of the agent contains 0.2 to 8% by weight of a mixed antioxidant accounting for the total amount of the grease composition, and the mixed antioxidant is (A) a dialkyl dithiocarbamate compound and (B) as an antioxidant. ) The aromatic amine compound is compounded in a weight ratio of 90-10:10-90.

As the base oil used in the present invention, one or more base oils selected from synthetic oils such as mineral oil, diester oil, polyol ester oil, poly-α-olefin oil, and polyphenylene ether oil can be used. In particular, a mixed oil of polyol ester oil and alkylphenyl ether oil is excellent in thermo-oxidative stability.

Polyol ester (polyol-luestel) oil, preferably a polyol ester oil synthesized from a polyol having a carbon skeleton of neopentane and a fatty acid with a carbon number of 5 to 18 or an aliphatic monohydric oil with a carbon number of 4 to 10 Coordination compound type polyol ester oil composed of mixed acids of carboxylic acid and aliphatic dicarboxylic acid and polyols of trimethylolethane, trimethylolpropane, pentaerythritol, and dipentaerythritol. Specific examples of fatty acids include butyric acid, valeric acid, caproic acid, heptanoic acid, octanoic acid, 2-ethylhexanoic acid, isooctanoic acid, nonanoic acid, isononanoic acid, capric acid, isodecanoic acid, stearic acid, etc. . Specific examples of polyols include trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and the like.

The alkyl phenyl ether oil is an alkyl diphenyl ether oil or an alkyl polyphenyl ether oil with a substituent having 10 to 22 carbon atoms, preferably 10 to 16 carbon atoms. The compounding ratio of polyol ester oil and alkyl phenyl ether oil is 80-20:20-80 weight ratio, and preferably 70-30:30-70 weight ratio.

When the compounding ratio of polyol ester oil and alkyl phenyl ether oil is outside this range, good thermo-oxidative stability cannot be obtained. The content of the base oil in the lubricating ester composition is not particularly limited, but in order to obtain a long life, it is preferably 70 to 95% by weight, more preferably 80 to 90% by weight. When the base oil content is less than 70% by weight, the grease becomes hard, and when it is more than 95% by weight, it becomes soft, both of which have an adverse effect on lubrication.

In order to greatly improve the thermo-oxidative stability of lubricating oils and greases, the blended antioxidants are (A) dialkyldithiocarbamate compounds in the form of peroxide decomposition and free radical chain termination (B) Aromatic amine compounds. The mixing ratio of the mixed antioxidant is 90-10:10-90 by weight, preferably 80-20:20-80 by weight. The content of the mixed antioxidant is 0.2-8 by weight relative to the total amount of grease, preferably 0.5-80 by weight. 6% by weight. When the mixing ratio of the antioxidant is out of this range, good thermo-oxidative stability cannot be obtained. Furthermore, when the added amount of the mixed antioxidant is less than 0.2% by weight, the effect of preventing oxidation and deterioration is small, and when it is more than 8% by weight, the added effect becomes saturated.

Specific examples of the dialkyldithiocarbamate compound (A) include zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, dibutyldithioamino Zinc formate, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, sodium dibutyldithiocarbamate, nickel diethyldithiocarbamate, nickel dibutyldithiocarbamate, Copper dimethyldithiocarbamate, iron diethyldithiocarbamate, selenium diethyldithiocarbamate, tellurium diethyldithiocarbamate and zinc butyl xanthate, etc., especially preferred Nickel dibutyldithiocarbamate.

Specific examples of the aromatic amine compound (B) include: phenyl-α-naphthylamine, alkylated phenyl-α-naphthylamine, alkylated diethylamine with butyl, octyl, nonyl, etc. Aniline, N,N'-di-2-naphthyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, etc. Especially preferred are phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, alkylated diphenylamines.

The preferred combination of dialkyldithiocarbamate compound (A) and aromatic amine compound (B) includes zinc dimethyldithiocarbamate and phenyl-α-naphthylamine, dimethyl Zinc dithiocarbamate and alkylated phenyl-alpha-naphthylamine, zinc dimethyldithiocarbamate and alkylated diphenylamine, sodium dimethyldithiocarbamate and phenyl-alpha-naphthylamine , sodium dimethyldithiocarbamate and alkylated phenyl-α-naphthylamine, sodium dimethyldithiocarbamate and alkylated diphenylamine, nickel dibutyldithiocarbamate and phenyl-α -Naphthylamine, nickel dibutyldithiocarbamate and alkylated diphenylamine, etc. In particular, preferred combinations are nickel dibutyldithiocarbamate and phenyl-α-naphthylamine, nickel dibutyldithiocarbamate and alkylated phenyl-α-naphthylamine, and dibutyl dithiocarbamate Nickel Thiocarbamate and Alkylated Diphenylamine.

Dialkyldithiocarbamate compounds have a property of corroding or discoloring copper or copper alloy materials depending on the conditions of use. When used in the coexistence of such materials, it is best to add some additives to prevent corrosion and discoloration as needed. Benzotriazoles and benzotriazole-based compounds are effective as anticorrosion agents. The compounding amount thereof is preferably 0.01 to 2% by weight based on the total weight of the lubricating oil composition and the grease composition.

The kinematic viscosity of the base oil used in the present invention is 20 to 30 mm ² /S at 40°C, preferably 30 to 200 mm ² /S. As the thickener used in the grease of the present invention, there are known lithium soaps, lithium complex soaps and diurea compounds. Thickener and its compounding amount can be selected arbitrarily according to the service conditions of the grease, and it is best to use 10-20% by weight or about NO.2-3 according to the NLGI consistency for larger-diameter bearings.

Furthermore, rust inhibitors, oily agents, extreme pressure lubricant additives, solid lubricants, and the like may be added to the lubricating oil composition or grease composition of the present invention as needed.

The lubricating oil composition of the present invention may be used alone or as a component constituting the lubricating grease composition of the present invention for various purposes. It is preferably used for bearings, and more preferably suitable for large-diameter bearings.

The lubricating oil composition and the lubricating grease composition of the present invention are excellent in heat resistance, oxidation stability and lubricity by blending polyol ester oil and alkyl phenyl ether oil in a predetermined ratio with the base oil. This base oil contains a mixed antioxidant of a dialkyl dithiocarbamate compound and an aromatic amine compound, so even in the presence of copper and copper alloy materials, etc., the evaporation of the mixed base oil can be greatly suppressed Changes in loss, viscosity, total acid number, etc.

Grease is known to form a thinner oil film on the lubricating surface of the bearing than oil lubrication. As a result, the lubricated surfaces tend to be in direct contact with boundary lubrication conditions, and wear tends to occur. The base oil of the present invention can reduce the evaporation amount and viscosity change of lubricated part oil, so it exhibits low friction and suppresses temperature rise. As a result, even at high temperature and high speed, it greatly contributes to the extension of the life of the grease.

When the bearing diameter is large, the separation characteristics of the base oil from the grease are important. As the base oil, an appropriate amount of base oil with little evaporation loss, oxidation deterioration, and viscosity change is continuously supplied to the lubricating surface for a long period of time. Therefore, thermal oxidation stability, shear stability, and base oil retention of the thickener are important. Due to the use of these lithium soaps, lithium complex soaps, diurea compounds and mixed antioxidants added with antioxidant dialkyldithiocarbamate compounds and aromatic amine compounds, it can be greatly improved. The thickener is resistant to oxidation and deterioration, and the base oil can be supplied to the lubricating surface for a long time, so it can realize the long life of the grease.

Hereinafter, the present invention will be described in more detail based on examples and comparative examples. The evaluation test methods of the lubricating oils and greases of Examples and Comparative Examples are as follows.

(Test method for evaluation of antioxidants)

(1) Evaluation test method for heating deterioration (oxidation deterioration)

Regarding the lubricating oil and grease containing an antioxidant, the effect of adding an antioxidant was evaluated. Heat the lubricating oil mixed with anti-oxidant according to the specified temperature. The evaluation of anti-oxidant of lubricating grease is to measure the total acid value and viscosity of the lubricating oil after coating the lubricating grease with a thickness of 3 mm on the test material, heating under the specified temperature conditions, and extracting with petroleum ether. The smaller the change in these characteristics, the greater the effect of the addition of an antioxidant, and the more excellent it is in preventing oxidative deterioration of lubricating oil.

① Evaporation measurement method

Take 20 g of lubricant added with antioxidant in a glass beaker, let it stand in a thermostat at 150°C for 1200 hours, and measure the evaporation according to the weight change before and after heating. The amount of evaporation in this test includes the evaporation of light oil in lubricating oil and volatile substances generated by oxidation degradation, and the greater the oxidation degradation, the greater the amount of volatile substances generated, so the evaporation amount is larger.

②Determination method of total acid value

For the lubricating oil after the heat deterioration test, measure the total acid value according to JIS K 250 1 method and obtain the change before and after the heat deterioration test.

③Viscosity measurement method

For the lubricating oil after the heat deterioration test, the kinematic viscosity at 40°C was measured according to the viscosity measurement method of JIS K 2283, and the evaluation was performed based on the viscosity ratio before and after heating. The viscosity ratio was obtained by the following formula.

Viscosity ratio = viscosity after heating deterioration / viscosity before heating

(2) Accelerated lubrication life test of rolling bearings

Fill the cylindrical rolling bearing (NU 314) with 5g of grease, and evaluate the lubricating performance according to the following conditions. Grease lubrication life (h), defined as the movement time when the bearing temperature rises by 10°C from the test temperature

·Number of rotations: 8000rpm

Load: 500kgf

·Test temperature: 100℃

Examples 1-18 and Comparative Examples 1-20

The embodiment is to add the antioxidant (A) dialkyl dithiocarbamate to the base oil in which the weight ratio of alkyl phenyl ether oil and polyol ester oleylamine 50:50 is matched as shown in Table 1. Nickel dibutyldithiocarbamate (Nokrac NBC: Ouchi Shinko Chemical Co., Ltd.) and (B) phenyl-α-naphthylamine (Nokrac PA: Ouchi Shinko Chemical Co., Ltd.) of aromatic amines (manufactured by Co., Ltd.) Lubricating oil composed of 1% by weight of mixed antioxidants combined at a weight ratio of 50:50. A comparative example is a lubricating oil in which 1% by weight of an antioxidant was added to the base oil shown in Table 2. A brass plate serving as an oxidation catalyst was immersed in each lubricating oil, and heated at 150° C. for 1,200 hours. The evaporation amount, total acid value, and viscosity ratio after the heat degradation test were measured to evaluate the effect of adding an antioxidant against the oxidative degradation of lubricating oil. Table 3 shows Examples 1-18, and Table 4 shows the results of Comparative Examples 1-22.

Table 1 Example Mixed oil (mixing ratio 50:50) Mixed antioxidant (mixing ratio 50:50) polyol ester oil Alkyl phenyl ether oil (A) Dialkyl dithiocarbamate compounds (B) Aromatic amine compounds alcohol Fatty acid 1 Trimethylolpropane Caproic acid (nC ₆ ) Alkyl Diphenyl Ether (Moresco Hail-bu LB-100) Nickel dibutyldithiocarbamate [Nocratsu NBC] Phenyl-α-Naphthylamine [Nocluck PA] 2 Caprylic acid (nC ₈ ) 3 Capric acid (nC ₁₀ ) 4 Isooctanoic acid (iso-C ₈ ) 5 Isotridecanoic acid (iso-C ₁₃ ) 6 Mixed Fatty Acids (mix-C ₄ ) 7 ″ (mix-C _6-10 ) 8 ″ (mix-C _9-10 ) 9 isooctanoic acid 10 pentaerythritol Isodecanoic acid 11 Mixed Fatty Acids (mix-C ₄ ) 12 ″ (mix-C ₆ ) 13 ″ (mix-C _9-10 ) 14 Di-(2-ethylhexyl) sebacate 15 trimethylolpropane tricaprylate 16 Alkyl diphenyl ether 17 poly-alphaolefin 18 Mineral oil (500NT oil)

Table 2 comparative example Base oil (mixing ratio 50:50) Antioxidant 1 Trimethylolpropane Triheptanoate (Reolube LT2100: C ₇ ) Nickel dibutyldithiocarbamate (Nocluck NBC: Oh Nass Yoka Co., Ltd.) 2 ″ Decanoate (Reolube LT3000: C ₁₀ ) 3 Pentaerythritol Tetraheptanoate (Reolube LP2800: C ₇ ) 4 Alkyl Diphenyl Ether (morescohiru-bu LB-100) 5 Poly-alpha-olefin (Mo-ビル Petroleum: Ethylflo 170) 6 Mineral oil (500NT oil) 7 Trimethylolpropane Triheptanoate (Reolube LT2100: C ₇ )/Poly-alphaolefin 8 Alkyl diphenyl ether (moresukohiru-bu LB-100)/poly-α-olefin (mo-biru petroleum: Ethylflo 170) 9 Mineral oil/poly-α-olefin (500NTオイル/モ-ビル oil: Ethylflo 170) 10 Trimethylolpropane Triheptanoate (Reolube LT2100: C ₇ ) Phenyl-α-Naphthylamine (Nokurac PA: Ouchi Shinyo Chemical Co., Ltd.) 11 ″ Decanoate (Reolube LT3000: C ₁₀ ) 12 Pentaerythritol Tetraheptanoate (Reolube LP2800: C ₇ ) 13 Alkyl Diphenyl Ether (morescohiru-bu LB-100) 14 Poly-alpha-olefin (Mo-ビル Petroleum: Ethylflo 170) 15 Mineral oil (500NT oil) 16 Trimethylolpropane Triheptanoate (Reolube LT2100: C ₇ )/Poly-alphaolefin 17 Pentaerythritol tetraheptanoate (Reolube LP2800: C ₇ )/Poly-alphaolefin 18 Alkyl diphenyl ether (morescohiru-bu LB-100)/poly-α-olefin 19 Mineral oil/poly-alphaolefin (500NT oil/モ-ビル oil: Ethylflo 170) 20 Trimethylolpropane Triheptanoate (Reolube LT2100)/Poly-α-olefin (Mo-blur Petroleum: Ethylflo 170) Pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate (Ilganox 1010: CIBA GEIGY) twenty one Alkyl diphenyl ether (moresukohairu-bu LB-100)/poly-α-olefin (mo-biru petroleum: Ethylflo 170) 2,2'-Methylene bis(4-ethyl-6-tert-butylphenol) (Nokraku NS-5: Ouchi Shinyo Chemical Co., Ltd.) twenty two Trimethylolpropane Triheptanoate (Reolube LT2100)/Poly-alphaolefin (Mo-blur Petroleum: Ethylflo 170) no additives

table 3 Example Oxidation degradation of lubricating oil (150℃×1200h) no catalyst Brass (JIS H3250) Evaporation (wt%) Total acid value (mgKOH/g) Viscosity ratio Evaporation (wt%) Total acid value (mgKOH/g) Viscosity ratio 1 0.45 0.08 1.07 0.58 0.11 1.09 2 0.44 0.08 1.07 0.53 0.10 1.10 3 0.42 0.07 1.06 0.50 0.09 1.08 4 0.41 0.05 1.07 0.48 0.08 1.09 5 0.40 0.05 1.05 0.50 0.09 1.08 6 0.40 0.06 1.06 0.52 0.08 1.08 7 0.38 0.04 1.05 0.43 0.07 1.07 8 0.39 0.05 1.05 0.46 0.06 1.08 9 0.35 0.05 1.07 0.45 0.07 1.09 10 0.38 0.07 1.06 0.46 0.09 1.08 11 0.37 0.06 1.05 0.45 0.08 1.07 12 0.40 0.07 1.04 0.58 0.10 1.05 13 0.39 0.06 1.06 0.57 0.09 1.08 14 0.44 0.06 1.05 0.61 0.18 1.07 15 0.39 0.05 1.06 0.55 0.12 1.06 16 0.41 0.06 1.05 0.58 0.14 1.05 17 0.38 0.06 1.07 0.59 0.15 1.06 18 0.42 0.06 1.05 0.62 0.18 1.09

Table 4 comparative example Oxidation degradation of lubricating oil (150℃×1200h) no catalyst Brass (JIS H3250) Evaporation (wt%) Total acid value (mgKOH/g) Viscosity ratio Evaporation (wt%) Total acid value (mgKOH/g) Viscosity ratio 1 0.71 0.42 1.12 0.85 0.54 1.15 2 0.75 0.39 1.09 0.86 0.41 1.13 3 0.86 0.48 1.13 0.90 0.56 1.16 4 0.87 0.50 1.11 0.91 0.63 1.18 5 0.92 0.49 1.08 1.08 0.56 1.12 6 0.89 0.68 1.14 1.09 0.78 1.20 7 0.86 0.57 1.11 1.08 0.68 1.16 8 0.84 0.61 1.08 1.10 0.73 1.14 9 0.97 0.70 1.07 1.05 0.81 1.10 10 1.20 0.79 1.13 1.66 0.88 1.19 11 1.11 0.80 1.18 1.56 0.96 1.23 12 1.08 0.97 1.20 1.51 1.05 1.28 13 1.18 0.88 1.21 1.46 0.97 1.26 14 1.46 0.96 1.22 1.72 1.04 1.29 15 1.26 0.89 1.18 1.87 1.09 1.27 16 1.18 0.97 1.24 1.78 1.13 1.30 17 1.22 1.11 1.21 1.41 1.21 1.26 18 1.17 1.01 1.24 1.59 1.16 1.29 19 1.28 0.95 1.23 1.86 1.15 1.30 20 1.12 1.21 1.25 1.40 1.42 1.28 twenty one 1.34 1.09 1.24 1.75 1.28 1.31 twenty two 5.53 4.15 1.45 5.89 5.02 1.59 Examples 19-36 and Comparative Examples 23-44

Lithium soap greases using lubricating oils added with antioxidants shown in Examples 1 to 18 in Table 1 and Comparative Examples 1 to 22 in Table 2 were examined. The manufacture of lithium soap grease was carried out as follows.

Add 180 g of stearic acid to a total amount of 410 g of alkyl diphenyl ether oil, heat to the temperature of complete dissolution (80-90° C.) while stirring, and add 28 g of lithium hydroxide and 56 g of hot water at this temperature. The mixture was saponified at 95-100°C for 1 hour under stirring. Then, after heating to about 210° C. for 5 minutes with stirring, 410 g of polyol ester oil was added, stirred and cooled. Use it as a base grease.

Take 891g of this base grease, add 9g of anti-oxidant, heat to 100°C with stirring, and then cool to room temperature with stirring. Then, use a three-roll mill to knead 2-3 times to prepare lithium soap grease with NLGI consistency grade No. 2. Coat this lithium soap grease on a glass plate and a brass plate, and after a 1200-hour heat degradation test at a temperature of 150°C, measure the total acid value and viscosity ratio of the extracted base lubricating oil, and evaluate the grease oxidative degradation. And, the lubrication performance was evaluated by the accelerated lubrication life test of the rolling bearing. Table 5 shows the results of Examples 19-36 and Comparative Examples 23-44.

Examples 37-54 and Comparative Examples 45-49

Lithium complex soaps using the lubricating oils of Examples 1 to 18 in Table 1 and Comparative Examples 45 to 49 shown in Table 6 were investigated.

table 5 No. Oxidation degradation of grease (150℃×1200h) Lubrication life (h) no catalyst Brass (JIS H3250) Total acid value (mgKOH/g) Viscosity ratio Total acid value (mgKOH/g) Viscosity ratio Example 19 0.10 1.08 0.14 1.10 520 20 0.11 1.09 0.15 1.11 - twenty one 0.09 1.08 0.13 1.11 654 twenty two 0.08 1.09 0.13 1.12 - twenty three 0.07 1.09 0.15 1.12 568 twenty four 0.08 1.08 0.14 1.11 - 25 0.08 1.08 0.14 1.10 657 26 0.09 1.08 0.15 1.11 - 27 0.09 1.09 0.16 1.13 593 28 0.11 1.10 0.18 1.15 - 29 0.12 1.11 0.19 1.16 574 30 0.10 1.10 0.17 1.17 - 31 0.09 1.08 0.15 1.11 568 32 0.26 1.10 0.34 1.17 528 33 0.21 1.09 0.27 1.16 567 34 0.23 1.10 0.26 1.15 570 35 0.26 1.13 0.31 1.19 510 36 0.27 1.12 0.36 1.18 505 comparative example twenty three 0.45 1.17 0.51 1.20 - twenty four 0.44 1.13 0.56 1.18 285 25 0.51 1.16 0.66 1.19 - 26 0.54 1.17 0.62 1.22 310 27 0.51 1.11 0.66 1.20 - 28 0.70 1.17 0.82 1.21 295 29 0.61 1.15 0.73 1.28 - 30 0.67 1.13 0.73 1.25 312 31 0.76 1.13 0.82 1.26 - 32 0.82 1.18 0.95 1.25 305 33 0.83 1.21 0.96 1.25 - 34 1.03 1.25 1.17 1.38 229 35 0.95 1.24 1.09 1.33 - 36 1.05 1.26 1.14 1.36 295 37 0.93 1.24 1.18 1.40 - 38 1.01 1.30 1.17 1.42 236 39 1.16 1.29 1.29 1.35 - 40 1.05 1.28 1.17 1.41 240 41 1.04 1.27 1.25 1.40 - 42 1.27 1.29 1.37 1.32 230 43 1.14 1.28 1.30 1.51 - 44 4.25 1.76 5.39 1.88 210

Table 6 comparative example Base oil (mixing ratio 50:50) Antioxidant 45 Trimethylolpropane Triheptanoate/Poly-alphaolefin Nickel dibutyldithiocarbamate, (Nocluck NBC) 46 Alkyl diphenyl ether/poly-alphaolefin 47 Mineral oil/poly-alphaolefin 48 Trimethylolpropane Triheptanoate/Poly-alphaolefin Alkylated phenyl-α-naphthylamine (Iluganox LO6) 49 Alkyl diphenyl ether/poly-alphaolefin 2,2'-Methylene bis(4-ethyl-6-tert-butylphenol) (Nocluck NS-5)

Lithium complex soap grease was produced as follows.

Add 106.6 g of 12-hydroxystearic acid and 23.4 g of azelaic acid to 435 g of alkyl diphenyl ether oil in total, heat and dissolve to 80-90° C. while stirring. A mixture of 26.1 g of lithium hydroxide and 52.2 g of hot water was added at this temperature, and a saponification reaction was performed at 95 to 100° C. for 1 hour while stirring. Then heat while stirring until about 210°C for 5 minutes, add 435g of polyol ester oil, stir and cool. Use it as a base grease.

Take 891 g of this base grease, add 9 g of antioxidant, heat to 100°C while stirring, and then cool to room temperature with stirring. Then, it was kneaded 2 to 3 times with a three-roll mill. Prepare the lithium complex soap grease with NLGI consistency grade NO.2. This lithium complex soap was subjected to the same heating deterioration test and accelerated lubrication life test as in Example 19. The results are shown in Table 7.

Table 7 No. Oxidation degradation of grease (150℃×1200h) Lubrication life (h) no catalyst Brass (JISH3250) Total acid value (mgKOH/g) Viscosity ratio Total acid value (mgKOH/g) Viscosity ratio Example 37 0.10 1.09 0.14 1.10 545 38 0.09 1.08 0.15 1.10 - 39 0.10 1.08 0.14 1.11 640 40 0.09 1.08 0.13 1.11 - 41 0.07 1.09 0.14 1.12 672 42 0.08 1.08 0.14 1.10 - 43 0.09 1.09 0.15 1.10 650 44 0.09 1.08 0.15 1.12 - 45 0.10 1.08 0.15 1.11 620 46 0.12 1.09 0.18 1.14 - 47 0.11 1.10 0.18 1.16 615 48 0.10 1.10 0.17 1.16 - 49 0.09 1.09 0.16 1.14 645 50 0.26 1.13 0.31 1.17 531 51 0.24 1.10 0.30 1.15 570 52 0.23 1.11 0.28 1.14 598 53 0.26 1.11 0.30 1.15 580 54 0.28 1.13 0.35 1.19 568 comparative example 45 0.61 1.14 0.72 1.23 310 46 0.65 1.13 0.71 1.24 325 47 0.73 1.17 0.80 1.23 317 48 1.01 1.28 1.11 1.42 324 49 1.04 1.23 1.15 1.41 308

Examples 55-72 and Comparative Examples 50-54

These examples are diurea greases using the same lubricating oil as in Examples 1 to 18 in Table 1 and Comparative Examples 45 to 49 shown in Table 6.

Diurea grease is manufactured as follows.

Add 78.8 g of 4,4'-diphenylmethane dicyanate to 420 g of alkyl diphenyl ether oil, heat and dissolve under stirring until 70-75°C. A mixture in which 81.2 g of octylamine was dissolved in 420 g of polyol ester oil was added at 70 to 75° C., and reacted at 95 to 100° C. for 1 hour while stirring. It was then heated with stirring up to 170°C. After holding for 30 minutes, it was cooled to room temperature with stirring. Specify it as a base grease.

Take 891g of this grease, add 9g of mixed antioxidant, heat to 100°C with stirring, then cool to room temperature with stirring. Then, it was kneaded 2 to 3 times with a three-roll mill. A diurea grease of NLGI consistency classification No. 2 was prepared. This biurea grease was subjected to the same heating deterioration test and accelerated lubrication life test as in Example 19. The results are shown in Table 8.

Examples 73-84

A base that mixes pentaerythritol tetraheptanoate (Reol-Bu LP3200 manufactured by CIBA-GEIGY) and dialkyl tetraphenyl ether (manufactured by Matsumura Research Co., Ltd.: S-3230) at a weight ratio of 50:50 Add the combination of antioxidant (A) dialkyl dithiocarbamate compound and (B) aromatic amine compound shown in Table 9 to the oil, and mix the two in a weight ratio of 50:50. Antioxidant 1% by weight, lithium soap grease was prepared in the same manner as in Example 19. This grease was coated on a brass plate to a thickness of 3 mm, and a heat deterioration test was performed at a temperature of 150° C. for 1,200 hours. Determination of total acid value and viscosity ratio after extracting base oil from heat-deteriorated grease. The results are shown in Table 9.

Table 8 No. Oxidation degradation of grease (150℃×1200h) Lubrication life (h) no catalyst Brass (JISH3250) Total acid value (mgKOH/g) Viscosity ratio Total acid value (mgKOH/g) Viscosity ratio Example 55 0.10 1.07 0.14 1.10 580 56 0.11 1.08 0.14 1.10 - 57 0.08 1.07 0.12 1.11 540 58 0.08 1.07 0.15 1.11 - 59 0.07 1.08 0.14 1.11 545 60 0.08 1.08 0.13 1.10 - 61 0.08 1.09 0.13 1.10 620 62 0.08 1.08 0.15 1.11 - 63 0.09 1.08 0.14 1.12 - 64 0.09 1.08 0.16 1.13 581 65 0.11 1.09 0.17 1.13 - 66 0.11 1.10 0.16 1.14 - 67 0.10 1.10 0.18 1.14 670 68 0.26 1.12 0.30 1.16 520 69 0.24 1.11 0.27 1.15 540 70 0.22 1.11 0.27 1.14 550 71 0.23 1.12 0.26 1.13 530 72 0.28 1.13 0.31 1.16 215 comparative example 50 0.60 1.13 0.70 1.24 485 51 0.63 1.14 0.70 1.22 350 52 0.68 1.17 0.73 1.23 385 53 1.01 1.21 1.00 1.31 400 54 1.04 1.24 1.14 1.39 335

Table 9 Oxidation degradation of grease (150℃×1200h) Example Antioxidant (mixing ratio 50:50) Brass (JISH3250) (A) Alkyl dithiocarbamate compounds (B) Aromatic amine compounds Total acid value (mg KOH/g) Viscosity ratio 73 Zinc Dimethyl Dithiocarbamate Alkylated phenyl-α-naphthylamine 0.09 1.07 74 ″ sodium 0.15 1.08 75 " copper 0.17 1.08 76 Zinc diethyldithiocarbamate 0.07 1.07 77 ″ sodium 0.10 1.08 78 ″ Nickel 0.11 1.08 79 " iron 0.16 1.09 80 ″ selenium 0.13 1.09 81 ″ tellurium 0.13 1.09 82 Zinc dibutyldithiocarbamate 0.09 1.07 83 ″ sodium 0.14 1.08 84 ″ Nickel 0.09 1.07

Examples 85-90

Monoalkyltriphenyl ether (manufactured by Matsumura Laboratory Co., Ltd.: S-3102) and trimethylolglyceride (complex type polyol ester, manufactured by CIBA-GEIGY Co., Ltd.: Reol-bu LT451) were prepared according to The base oil formulated at a weight ratio of 50:50 was added with the antioxidant (A) dialkyldithiocarbamate compound nickel dibutyldithiocarbamate shown in Table 10 (ノクラツクNBC: Ouchi Shinko Chemical Co., Ltd. and (B) aromatic amine compound phenyl-α-naphthylamine (Nocluck PA: Ouchi Shinko Chemical Co., Ltd.), alkylated phenyl-α-naphthylamine (Iluganox L06: manufactured by CIBA GEIGY), octyldiphenylamine (Nokurac AD-F: manufactured by Ouchi Shinko Chemical Co., Ltd.), dinonyldiphenylamine (BANLUBE DND: manufactured by Vanderbilt), alkylated diphenylamine (Iruganotkus L57 : CIBA GEIGY Co., Ltd.) and N,N'-diphenyl-p-phenylenediamine (ノクラツクDP: Ouchi Shinshin Chemical Co., Ltd.) in a 50:50 weight ratio of mixed antioxidant 1 weight %, Lithium complex soap grease was prepared in the same manner as in Example 37. This grease was subjected to the same heating degradation test and accelerated lubrication life test as in Example 19. The results are shown in Table 10.

Table 10 Oxidation degradation of grease (150℃×1200h) Example Antioxidant (mixing ratio 50:50) Brass (JIS H3250) Lubrication life (h) (A) Alkyl dithiocarbamate compounds (B) Aromatic amine compounds Total acid value (mgKOH/g) Viscosity ratio 85 Nickel dibutyldithiocarbamate Phenyl-α-naphthylamine 0.08 1.08 533 86 Alkylated phenyl-α-naphthylamine 0.06 1.06 655 87 Octyldiphenylamine 0.06 1.07 635 88 Dinonyldiphenylamine 0.07 1.09 630 89 Alkylated diphenylamine 0.08 1.08 640 90 N,N'-diphenyl-p-phenylenediamine 0.08 1.09 610

Examples 91-111 and Comparative Examples 55-60

Alkyl tetraphenyl ether (Matsumura Research Institute: S-3101) and pentaerythritol triester (complex type polyol ester, manufactured by CIBA-GEIGY: レオルル-ブLPE602) in a weight ratio of 50:50 Add antioxidant (A) dialkyl dithiocarbamate compound and (B) aromatic amine compound in the base oil that is formed by adding the mixed antioxidant 1 weight of the ratio shown in table 11 and table 12 %, prepare lithium complex soap grease in the same manner as in Example 37. This grease was subjected to the same heating deterioration test as in Example 73. Table 11 shows the results of Examples 91 to 111, and Table 12 shows the results of Comparative Examples 55 to 60.

Example 112

Pentaerythritol tetraester (complex type polyol ester; manufactured by Tekafufuin Chemical Co., Ltd.: Efcol-bu 100Z) and alkyl diphenyl ether (manufactured by Matsumura Laboratories Co., Ltd.: Moreskohairu-bu LB-100 (according to Add 0.1 to 8% by weight of the mixed antioxidant combined in the ratio shown in Table 13 to the base oil formulated at a weight ratio of 50:50, and prepare lithium complex soap grease in the same manner as in Example 37. This grease was subjected to the same heating deterioration test as in Example 73. The results are shown in Table 13.

Table 11 Oxidation degradation of grease (150℃×1200h) Example Antioxidant (mixing ratio) Brass (JIS H3250) (A) Alkyl dithiocarbamate compounds (B) Aromatic amine compounds Total acid value (mgKOH/g) Viscosity ratio Zinc Dimethyl Dithiocarbamate Sodium Dimethyl Dithiocarbamate Nickel dibutyldithiocarbamate Phenyl-α-naphthylamine Alkylated phenyl-α-naphthylamine Alkylated diphenylamine 91 10 90 0.10 1.06 92 50 50 0.08 1.06 93 90 10 0.10 1.07 94 10 90 0.08 1.07 95 50 50 0.07 1.06 96 90 10 0.10 1.06 97 10 90 0.10 1.07 98 50 50 0.06 1.06 99 90 10 0.09 1.07 100 10 90 0.09 1.07 101 90 10 0.08 1.06 102 10 90 0.08 1.07 103 90 10 0.09 1.08 104 10 90 0.07 1.07 105 90 10 0.08 1.08 106 10 90 0.09 1.08 107 90 10 0.08 1.07 108 10 90 0.10 1.08 109 90 10 0.09 1.07 110 10 90 0.06 1.07 111 90 10 0.07 1.06

Table 12 Oxidation degradation of grease (150℃×1200h) comparative example Antioxidant (mixing ratio) Brass (JIS H3250) (A) Alkyl dithiocarbamate compounds (B) Aromatic amine compounds Total acid value (mgKOH/g) Viscosity ratio Zinc Dimethyl Dithiocarbamate Sodium Dimethyl Dithiocarbamate Nickel dibutyldithiocarbamate Phenyl-α-naphthylamine Alkylated phenyl-α-naphthylamine Alkylated diphenylamine 55 5 95 0.31 1.11 56 95 5 0.29 1.13 57 5 95 0.29 1.13 58 95 5 0.32 1.12 59 5 95 0.35 1.13 60 95 5 0.28 1.15

Table 13 Oxidation degradation of grease (150℃×1200h) Embodiment 112 antioxidant (mixing ratio wt%) Total acid value (mgKOH/g) Viscosity ratio 0.1 0.2 0.5 2.0 5.0 6.0 8.0 0.1 0.2 0.5 2.0 5.0 6.0 8.0 Zinc Dimethyldithiocarbamate (10) Phenyl-α-Naphthylamine (90) 0.29 0.15 0.08 0.07 0.07 0.06 0.06 1.23 1.15 1.07 1.06 1.05 1.05 1.05 Zinc Dimethyldithiocarbamate (10) Alkylated Phenyl-α-Naphthylamine (90) 0.31 0.16 0.09 0.07 0.07 0.07 0.07 1.25 1.16 1.08 1.07 1.06 1.06 1.06 Nickel dibutyldithiocarbamate (10) Alkylated diphenylamine (90) 0.35 0.17 0.08 0.07 0.06 0.06 0.06 1.26 1.17 1.09 1.08 1.07 1.06 1.06

Examples 113-124

Trimethylolpropane trioctyl ester (Reolub LT3000), pentaerythritol tetraheptanoate (Reolub LP2800) and pentaerythritol tetraester (complex type polyol ester oil; manufactured by ㄕㄕテカフㄕイン Chemical Co., Ltd.) shown in Table 14 were used: A mixture of anti-oxidant (A) dialkyl is added to the base oil of Efcol-bu 100Z) and alkyl diphenyl ether (manufactured by Matsumura Laboratories Co., Ltd.: Moresco Hilu-bu LB-100) at a weight ratio of 50:50 Dithiocarbamate compound nickel dibutyldithiocarbamate (Nokuku NBC) and (B) aromatic amine compound alkylated phenyl-α-naphthylamine (Iluganox L06) for lubrication of 1% by weight Oil, prepare lithium soap grease in the same way as in Example 19. This grease was subjected to the same heating deterioration test as in Example 73. The results are listed in Table 14.

Table 14 Oxidation degradation of grease (150℃×1200h) Example Antioxidant (mixing ratio) Brass (JIS H3250) trimethylolpropane trioctyl ester Pentaerythritol tetraheptanoate Pentaerythritol tetraester (combrex type) Alkyl Diphenyl Ether (Moresco High-FLB-100) Total acid value (mgKOH/g) Viscosity ratio 113 10 90 0.10 1.13 114 20 80 0.07 1.07 115 90 10 0.11 1.14 116 80 20 0.07 1.08 117 10 90 0.10 1.13 118 20 80 0.07 1.07 119 90 10 0.12 1.13 120 80 20 0.07 1.07 121 10 90 0.10 1.13 122 20 80 0.07 1.08 123 90 10 0.12 1.13 124 80 20 0.08 1.07

As can be clearly seen from the examples, mineral oil, diester oil, polyol ester oil, alkyl phenyl ether oil and polyol ester oil and alkyl phenyl ether oil are combined in the base oil containing ( A) Alkyl dithiocarbamate compound and (B) aromatic amine compound mixed anti-oxidant lubricating oil, and lithium soap, lithium complex soap and diurea compound using the above lubricating oil Grease used as a thickener has less change in evaporation, total acid value, and viscosity ratio even at high temperatures than the lubricating oil and grease of the comparative example, and is excellent in thermal oxidation stability and lubrication life , has a great contribution to the maintenance-free bearing.

The lubricating oil composition and the lubricating grease composition of the present invention are excellent in thermal stability and oxidation stability even under high temperature conditions that conventional greases cannot cope with, and can prolong the service life of bearings and prevent damage to rotating machines, etc. Great contribution to maintenance.

Claims (8)

1. a lubricating oil composition, it is characterized in that, in the lubricating oil composition containing base oil and additive, contain the mixed antioxidant that accounts for the total weight of lubricating oil composition and be 0.2～8% by weight, this mixed antioxidant is (A) dialkyl dithiocarbamate compound and (B) aromatic amine compound as an antioxidant are blended in a weight ratio of 90-10:10-90. 2. The lubricating oil composition according to claim 1, characterized in that, as the antioxidant, (A) dialkyldithiocarbamate compound is nickel dibutyldithiocarbamate, (B) aromatic The amine compound is one or more compounds selected from the group consisting of phenyl-α-naphthylamine, alkylated phenyl-α-naphthylamine, and alkylated diphenylamine. 3. A lubricating oil composition, characterized in that, in the lubricating oil composition in which the base oil is a mixed oil of polyol ester oil and alkyl phenyl ether oil, the total weight of the lubricating oil composition is 0.2 to 8 % by weight of mixed antioxidant, the mixed antioxidant is the weight of (A) dialkyl dithiocarbamate compound and (B) aromatic amine compound as antioxidant by 90～10:10～90 It is made by matching. 4. The lubricating oil composition according to claim 3, characterized in that, as the antioxidant, (A) dialkyldithiocarbamate compound is nickel dibutyldithiocarbamate, (B) aromatic The amine compound is one or more compounds selected from the group consisting of phenyl-α-naphthylamine, alkylated phenyl-α-naphthylamine, and alkylated diphenylamine. 5. A lubricating grease composition is characterized in that, in the lubricating grease composition containing any thickener in base oil and lithium soap, lithium complex soap, diurea compound, contains The weight is a mixed antioxidant of 0.2 to 8% by weight, and the mixed antioxidant is to use (A) a dialkyl dithiocarbamate compound and (B) an aromatic amine compound as an antioxidant in a ratio of 90 to 10: The weight ratio of 10 to 90 is compounded. 6. The grease composition according to claim 5, characterized in that (A) dialkyldithiocarbamate compound in the above-mentioned antioxidant is nickel dibutyldithiocarbamate, (B) aromatic amine The compound is one or more compounds selected from the group consisting of phenyl-α-naphthylamine, alkylated phenyl-α-naphthylamine, and alkylated diphenylamine. 7. A grease composition, characterized in that the base oil is a mixed oil of polyol ester oil and alkylphenyl ether oil, and contains any thickening of lithium soap, lithium complex soap, and diurea compound In the lubricating grease of anti-oxidizing agent, it contains 0.2 to 8% by weight of mixed antioxidant in the total weight of the grease composition. The mixed antioxidant is composed of (A) dialkyl dithiocarbamate compound and (B) The aromatic amine compound is compounded in a weight ratio of 90-10:10-90. 8. The grease compound according to claim 7, characterized in that, as the antioxidant, (A) dialkyldithiocarbamate compound is nickel dibutyldithiocarbamate, (B) aromatic amine The compound is one or more compounds selected from the group consisting of phenyl-α-naphthylamine and alkylated dinaphthylamine.