JP5141079B2 - Lubricating oil composition - Google Patents

Description

  The present invention relates to a lubricating oil composition. More specifically, the present invention relates to a lubricating oil composition that can maintain a good dispersion state of a solid lubricant for a long time.

  Conventionally, lubricating oils used for sliding parts have been required to have good friction and wear characteristics. In general, oil-based agents, antiwear agents, and extreme pressure agents are used alone to meet these requirements. Alternatively, a plurality of them are blended. These lubricating oil compositions are used for sliding parts between metal-metal, metal-resin, and resin-resin, and can smoothly run without problems such as seizure and torque increase during sliding such as rotation, reciprocation, and swing. On the other hand, there are many negative effects such as metal corrosion, sludge generation, resin cracking and cracking on sliding members such as metal and resin. There's a problem.

  On the other hand, for example, polytetrafluoroethylene resin (PTFE) is used as a lubricant for a solid lubricant that is chemically relatively stable and exhibits friction characteristics and extreme pressure performance due to a layered structure. Yes. Although PTFE does not have a risk of corroding metal or resin, it has a large specific gravity of about 2.2 and has a problem that it easily settles when dispersed in a base oil.

In response to such problems, a lubricating oil composition that is easy to handle and has excellent economic efficiency by preventing or reducing the settling / separation of the solid lubricant by adding a wax to the lubricant, solid lubricant, or organic solvent. Has been proposed.
JP 2002-020775 A

  However, such a lubricating oil composition has to form a lubricating film by dispersing base oil and PTFE in an organic solvent, applying the dispersion to an application member, and then volatilizing the organic solvent. The operation was complicated.

  The object of the present invention is to provide a dispersion state of a solid lubricant dispersed in a base oil without impairing the fluidity, load resistance, and friction characteristics of the lubricant even when prepared without using an organic solvent. An object of the present invention is to provide a lubricating oil composition that can be held well for a long time.

An object of the present invention is to contain a solid lubricant which is a polytetrafluoroethylene resin in a base oil composed of a synthetic oil in a proportion of 0.1 to 5% by weight in the composition, and further a weight ratio with respect to the amount of the solid lubricant. Is achieved by a lubricating oil composition comprising a lithium-based soap, a lithium-based composite soap or a urea-based compound in an amount of 0.10 to 0.50.

  The lubricating oil composition of the present invention can be prepared without using an organic solvent, and a lithium-based (composite) soap or urea-based compound can be added to keep the dispersed state of the solid lubricant well for a long time. In addition, there are excellent effects that the fluidity, load resistance, and friction characteristics of the lubricant are not impaired. The lubricating oil composition of the present invention exhibiting such effects does not adversely affect any of the metallic or resin sliding members and can be effectively applied to these members. The lubricating oil composition can also be used as a dispersion or spray by being dispersed in an organic solvent.

As the solid lubricant, polytetrafluoroethylene resin (PTFE; specific gravity of about 2.2) is used . The PTFE solid lubricant is used in such a proportion that it accounts for 0.1 to 5% by weight, preferably 0.3 to 3% by weight in the composition. If the solid lubricant is used at a ratio below this, the effect of the solid lubricant will not be sufficiently exerted. On the other hand, if it is used at a ratio above this, the viscosity of the lubricating oil composition will be too high, and the fluidity will be low. It will be lost.

  PTFE produces polytetrafluoroethylene by methods such as emulsion polymerization, suspension polymerization, and solution polymerization of tetrafluoroethylene, and it is processed by methods such as thermal decomposition, electron beam irradiation decomposition, physical grinding, and the number average. A molecular weight Mn of about 1000 to 100000, preferably about 100000 to 200,000 is used. The molecular weight can also be controlled by using a chain transfer agent during the copolymerization reaction. The powdery fluororesin used generally has an average primary particle size of about 500 μm or less, preferably about 0.1 to 30 μm.

  As the base oil, at least one of a synthetic hydrocarbon oil, an ester synthetic oil and a glycol oil is used, and a mixed oil of these is preferably used. Synthetic hydrocarbon oils include poly α-olefins, ethylene-α-olefin co-oligomers, polybutenes or their hydrides, alkylbenzenes, alkyl naphthalenes, etc., and ester-based synthetic oils include polyol esters, dibasic fatty acid esters, Aromatic polyvalent carboxylic acid ester, phosphoric acid ester, phosphorous acid ester, carbonic acid ester, etc., and examples of glycol oil are polyoxypropylene glycol monoether, poly (oxyethylene-oxypropylene) glycol monoether, etc. Is done. When two or more kinds of base oils are used in combination, the ester synthetic oil is preferably used in a proportion of about 60 to 95% by weight.

These base oils generally have a kinematic viscosity at 40 ° C. (based on JIS K2283) of about 20 to 800 mm ² / sec. Of these, for bearings and bushes, those of about 20 to 250 mm ² / sec, preferably about 20 to 100 mm ² / sec are used, and chain oil, gear oil, etc. do not require low temperature properties, In applications in which heat resistance is important, a material having a temperature of about 100 to 800 mm ² / second, preferably about 100 to 400 mm ² / second is used. Here, if a base oil with a kinematic viscosity higher than this is used as a bearing application, the low temperature fluidity deteriorates and an increase in torque occurs at a low temperature range, while a base oil with a kinematic viscosity lower than this is used. It is not sufficient in terms of volatility, and a sufficient oil film cannot be maintained under high temperature conditions. Also, in applications that do not require low temperature resistance and place importance on heat resistance, using a base oil with a higher kinematic viscosity is satisfactory in terms of heat resistance, but a wide operating temperature range. On the other hand, it is not preferable from the viewpoint of obtaining good sliding characteristics. On the other hand, if a base oil having a kinematic viscosity lower than this is used, the heat resistance cannot be sufficiently satisfied.

  In the lubricating oil composition containing 0.1 to 5% by weight of the solid lubricant, the ratio of the lithium (composite) soap or urea compound to the solid lubricant is 0.10 to 0.50 by weight. Used. When lithium-based (composite) soap or urea-based compound is used at a ratio below this relative to the solid lubricant, sufficient dispersion stability cannot be obtained, whereas when used at a ratio above this, solid This is not preferable because the effect of reducing the friction and improving the load resistance of the lubricant is impaired.

The lithium-based soap includes (a) a lithium salt of an aliphatic monocarboxylic acid having 12 to 24 carbon atoms and / or an aliphatic monocarboxylic acid having 12 to 24 carbon atoms containing at least one hydroxyl group, preferably 12 -Lithium hydroxystearate salt, and lithium-based composite soap, (a) two or more types of component aliphatic monocarboxylic acid lithium-based composite soap or (a) component aliphatic monocarboxylic acid and (b) 2 carbon atoms Lithium-based complex soaps with ˜12 aliphatic dicarboxylic acids or their diesters and at least one of C7-24 aromatic monocarboxylic acids or their esters are used. As the urea compound, diurea, triurea, tetraurea, urea resin, etc., preferably a diurea compound is used. Specific examples of the diurea compound include those represented by the following general formula.
R ¹ NHCONHR ² NHCONHR ¹
R ¹ : a monovalent aliphatic hydrocarbon group having 6 to 24 carbon atoms or
Monovalent aromatic hydrocarbon group having 6 to 15 carbon atoms
R ² : a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms

In the composition, other additives such as antioxidants, rust inhibitors, corrosion inhibitors, extreme pressure agents, oiliness agents, viscosity index improvers, etc., which have been added to the lubricating oil in advance, are added to the lubricating oil in the past. These additives can be added as necessary to form a lubricant. Examples of the antioxidant include phenolic antioxidants such as 2,6-ditertiarybutyl-4-methylphenol and 4,4′-methylenebis (2,6-ditertiarybutylphenol), alkyldiphenylamine, Examples include amine-based antioxidants such as phenylamine, phenyl-α-naphthylamine, phenothiazine, alkylated phenyl-α-naphthylamine , and alkylated phenothiazine , and phosphoric acid-based antioxidants and sulfur-based antioxidants.

  Examples of the rust preventive agent include fatty acids, fatty acid amines, alkyl sulfonic acid metal salts, alkyl sulfonic acid amine salts, oxidized paraffins, polyoxyethylene alkyl ethers, and the like, and corrosion inhibitors include, for example, benzotriazole and benzimidazole. , Thiadiazole and the like.

  Examples of extreme pressure agents include phosphorous compounds such as phosphate esters, phosphite esters, phosphate ester amine salts, sulfur compounds such as sulfides and disulfides, dialkyldithiophosphate metal salts, and dialkyldithiocarbamic acid metal salts. And sulfur-based compound metal salts, chlorinated paraffin, chlorinated diphenyl and other chlorinated compounds.

  Examples of the oily agent include fatty acids or esters thereof, higher alcohols, polyhydric alcohols or esters thereof, aliphatic amines, fatty acid monoglycerides, montan waxes, amide waxes, and the like. Examples of other solid lubricants include boron nitride and silane nitride.

  Examples of the viscosity index improver include polymethacrylate, ethylene-propylene copolymer, polyisobutylene, polyalkylstyrene, styrene-isoprene copolymer hydride, and the like.

  The composition is prepared by adding a predetermined amount of a solid lubricant, a lithium (composite) soap or a urea compound to a lubricant obtained by adding other necessary additives to the base oil in advance, and then adding a homomixer, three rolls or a high-pressure homogenizer. In the method of sufficiently kneading.

  Next, the present invention will be described with reference to examples.

Example 1
Pentaerythritol C ₆ -C ₉ carboxylic acid ester 87.1% by weight
(Cognis product, 40 ° C kinematic viscosity; 23 mm ² / sec)
Synthetic hydrocarbon oil (Inobean product PAO 6, kinematic viscosity at 40 ℃; 31mm ² / sec) 10.3% by weight
Synthetic hydrocarbon oil (PAO 40, 40 ° C kinematic viscosity; 390mm ² / sec) 2.6% by weight
PMA-based viscosity index improver (Mw = 250,000) synthesized in 97.9 parts by weight of a mixed base oil in pentaerythritol C ₆ -C ₉ carboxylic acid ester, amine antioxidant (Ciba Specialty Chemicals) Lubricant A was prepared by blending 1.0 part by weight of Irganox L57) and 0.1 part by weight of a benzotriazole metal deactivator with a homomixer. The lubricating oil A had a kinematic viscosity at 40 ° C. of 25.3 mm ² / sec and an evaporation loss of 150 ° C. and 100 hours was 18.1% by weight.

  In 98.5 parts by weight of this lubricating oil A, 1 part by weight of PTFE (emulsion polymerization polytetrafluoroethylene; average primary particle size 0.2 μm; Mn of about 100,000 to 200,000) as a solid lubricant and 0.5 parts by weight of 12-hydroxystearic acid lithium salt A lubricating oil composition was prepared by mixing parts (weight ratio to solid lubricant 0.50). In the following Examples and Comparative Examples, the same viscosity index improver, antioxidant, metal deactivator and PTFE were used.

Example 2
In Example 1, the lubricating oil composition was prepared by changing the amount of lubricating oil A to 98.9 parts by weight and the amount of lithium 12-hydroxystearate to 0.1 parts by weight (0.10 weight ratio).

Example 3
In Example 1, a mixture of 93.0 parts by weight of Lubricant A, 5 parts by weight of PTFE and 2 parts by weight of 12-hydroxystearic acid lithium salt (0.40 in the same weight ratio) was used as the lubricating oil composition.

Example 4
Trimethylolpropane C ₈ -C ₁₂ carboxylic acid ester 72.9% by weight
(Cognis product, 40 ° C kinematic viscosity; 18 mm ² / sec)
Synthetic hydrocarbon oil (PAO 6, 40 ° C kinematic viscosity; 31mm ² / sec) 20.8% by weight
Synthetic hydrocarbon oil (PAO 40, 40 ° C kinematic viscosity; 390 mm ² / sec) 6.3 wt%
Lubricant B was prepared by blending 8.0 parts by weight of PMA viscosity index improver, 1.0 parts by weight of amine antioxidant and 0.1 parts by weight of benzotriazole metal deactivator with 90.9 parts by weight of mixed base oil. . The lubricating oil B had a kinematic viscosity at 40 ° C. of 60.3 mm ² / sec and an evaporation loss of 100 ° C. for 100 hours was 21.5% by weight.

  A lubricating oil composition was prepared by mixing 36.7 parts by weight of PTFE and 0.3 part by weight of lithium 12-hydroxystearate (0.10 weight ratio) with 96.7 parts by weight of this lubricant B.

Example 5
Synthetic hydrocarbon oil (Inobean product PAO 10, kinematic viscosity at 40 ℃; 68mm ² / sec) 98.9wt%
Amine antioxidant 1.0% by weight
Benzotriazole metal deactivator 0.1% by weight
Was added to prepare Lubricant C. The lubricating oil C had a kinematic viscosity at 40 ° C. of 69.1 mm ² / sec and an evaporation loss of 100 ° C. for 100 hours was 34.5% by weight.

  A lubricating oil composition was prepared by mixing 18.5 parts by weight of PTFE and 0.5 parts by weight of 12-hydroxystearic acid lithium salt (same weight ratio of 0.50) with 98.5 parts by weight of this lubricant C.

Example 6
In Example 1, 96.5 parts by weight of lubricating oil A, 3 parts by weight of PTFE, and 0.5 parts by weight (reaction product of tolylene diisocyanate and aniline) (a weight ratio of 0.17) were mixed as a lubricating oil composition. Used.

Example 7
In Example 4, 94.0 parts by weight of lubricant B as a lubricating oil composition, 5 parts by weight of PTFE, and 1 part by weight of a composite fatty acid lithium salt (composite soap of lithium 12-hydroxystearate and azelaic acid) (same weight ratio: 0.20) A mixture of was used.

Example 8
Ditridecyl adipate (Daihachi Chemical Products, Kinematic viscosity at 40 ° C; 24mm ² / sec) 98.9% by weight
Amine antioxidant 1.0% by weight
Benzotriazole metal deactivator 0.1% by weight
Was added to prepare Lubricant D. The lubricating oil D had a kinematic viscosity at 40 ° C. of 24.9 mm ² / sec and an evaporation loss of 100 ° C. for 100 hours was 25.0% by weight.

  A lubricating oil composition was prepared by mixing 18.9 parts by weight of PTFE and 0.1 parts by weight of lithium 12-hydroxystearate (same weight ratio of 0.10) with 98.9 parts by weight of this lubricant D.

Example 9
Trimethylolpropane C ₈ -C ₁₂ carboxylic acid ester 65.0 wt%
(Cognis product, 40 ° C kinematic viscosity; 18 mm ² / sec)
Polybutene 30.0% by weight
Amine antioxidant 2.5% by weight
C ₁₂ zinc dithiophosphate 2.5% by weight
Was added to prepare lubricating oil E. The lubricating oil E had a kinematic viscosity at 40 ° C. of 105 mm ² / sec and an evaporation loss of 100 ° C. for 100 hours was 10.5% by weight.

  A lubricating oil composition was prepared by mixing 94 parts by weight of this lubricant E with 5 parts by weight of PTFE and 1 part by weight of the above complex fatty acid lithium salt (same weight ratio: 0.20).

Example 10
Dipentaerythritol C ₈ -C ₁₀ carboxylic acid ester 70.0 wt%
(Cognis product, 40 ° C kinematic viscosity; 280mm ² / sec)
Trimellitic acid C _{8 to} C ₁₀ carboxylic acid ester 25.5% by weight
(Kao product, kinematic viscosity at 40 ℃; 46mm ² / sec)
Triphenyl phosphorothioate 1.0% by weight
(Ciba Specialty Chemicals product; Phosphorous wear inhibitor)
C ₁₂ zinc dithiophosphate 1.0% by weight
Amine antioxidant 2.5% by weight
Was added to prepare Lubricant F. The lubricating oil F had a kinematic viscosity at 40 ° C. of 300 mm ² / sec, an evaporation loss at 150 ° C. for 100 hours of 4.7% by weight.

  A lubricating oil composition was prepared by mixing 96.5 parts by weight of this lubricant F with 3 parts by weight of PTFE and 0.5 part by weight (reaction product of tolylene diisocyanate and aniline) (same weight ratio of 0.17).

Example 11
Poly (oxyethylene oxypropylene) glycol monoether 50.0% by weight
(Sanyo Chemical product, 40 ° C kinematic viscosity; 135mm ² / sec)
Poly (oxyethylene oxypropylene) glycol monoether 46.5% by weight
(Sanyo Chemical product, 40 ° C kinematic viscosity; 380 mm ² / sec)
Triphenyl phosphorothioate 0.5% by weight
(Ciba Specialty Chemicals product; Phosphorous wear inhibitor)
Amine antioxidant 2.5% by weight
Benzotriazole metal deactivator 0.5% by weight
Was added to prepare lubricating oil G. The lubricating oil G had a kinematic viscosity at 40 ° C. of 215 mm ² / sec and an evaporation loss of 100 ° C. for 100 hours was 40.5% by weight.

  A lubricating oil composition was prepared by mixing 98.5 parts by weight of this lubricant G with 1 part by weight of PTFE and 0.5 parts by weight of lithium 12-hydroxystearate (the same weight ratio of 0.50).

Comparative Example 1
In Example 1, a mixture of 96.95 parts by weight of lubricant A, 3 parts by weight of PTFE and 0.05 parts by weight of 12-hydroxystearic acid lithium salt (0.02 in the same weight ratio) was used as the lubricating oil composition.

Comparative Example 2
In Example 1, a mixture of 85 parts by weight of the lubricant A, 10 parts by weight of PTFE and 5 parts by weight of 12-hydroxystearic acid lithium salt (0.50 in the same weight ratio) was used as the lubricating oil composition.

Comparative Example 3
In Example 1, as a lubricating oil composition, 82 parts by weight of lubricating oil A, 10 parts by weight of PTFE, and 8 parts by weight (reaction product of tolylene diisocyanate and aniline) (same weight ratio 0.80) were mixed. Used.

Comparative Example 4
In Example 4, a mixture of 85 parts by weight of lubricant B, 10 parts by weight of PTFE, and 5 parts by weight of a composite fatty acid lithium salt (same weight ratio of 0.50) was used as the lubricating oil composition.

Comparative Example 5
In Example 1, a mixture of 98 parts by weight of lubricant A, 1 part by weight of PTFE, and 1 part by weight of 12-hydroxystearic acid lithium salt (1.00 weight ratio) was used as the lubricating oil composition.

Comparative Example 6
In Example 5, a mixture of 95 parts by weight of lubricating oil C, 3 parts by weight of PTFE and 2 parts by weight of lithium 12-hydroxystearate (0.67 in the same weight ratio) was used as the lubricating oil composition.

Comparative Example 7
In Example 10, a lubricating oil composition in which 92 parts by weight of lubricant F, 5 parts by weight of PTFE and 3 parts by weight of 12-hydroxystearic acid lithium salt (same weight ratio: 0.60) were used.

The fluidity and dispersion stability of the lubricating oil compositions obtained in the above Examples and Comparative Examples were examined.
Fluidity: Viscosity was measured using a cone-plate rheometer at 25 ° C and a shear rate of 300 / sec, and 5,000 mPa · sec or less was evaluated as good fluidity. Dispersibility: Sedimentation with a 10 ml scale In the tube, put 10 ml of the lubricating oil composition obtained in each Example and Comparative Example in the synthetic oil, leave it for one week after stirring, and visually confirm the sedimentation state of the dispersed solid lubricant particles. The one in which a uniform dispersion was obtained without causing the particles to aggregate and settle was evaluated as having good dispersibility.

  As a result, in the lubricating oil compositions obtained in each of Examples and Comparative Examples 5 to 7, both fluidity and dispersion stability were good, but in the lubricating oil composition obtained in Comparative Example 1, Although the fluidity is good, the dispersion stability is insufficient. In the lubricating oil compositions obtained in Comparative Examples 2 to 4, the dispersion stability is good, but the fluidity is poor and does not function as a lubricating oil. It was a thing.

  In addition, a sliding property test (evaluation of load resistance and measurement of friction coefficient) was performed using each lubricating oil composition. Using a SRV friction tester, the load resistance was measured using a SUJ2 disk for the lower test piece and a SUJ2 ball of 10 mm diameter for the upper test piece, which were point-contacted, with a frequency of 50 Hz, an amplitude of 1 mm, and a temperature of 100 ° C. Under the conditions, the load was increased by 50N every minute, this was continuously performed until it reached 500N, the maximum load at which seizure did not occur was evaluated, and the friction coefficient was measured for each load. The reason for setting the test temperature to 100 ° C. is to make it difficult to hold the oil film.

The results obtained are shown in the following table. It is shown that the lubricating oil compositions of Comparative Examples 5 to 6 having good fluidity and dispersion stability have large friction coefficients and inferior load resistance compared to the numerical values of the corresponding examples. Further, the lubricating oil composition of Comparative Example 7 has a larger coefficient of friction than that of Example 10.
table
Load (N) / Contact surface pressure (N / mm ² )
Withstand load 50/100/150/200/250/300/350/400/450/500 /
Example (N) 105 149 183 211 236 258 279 298 316 333
Example 1> 500 0.142 0.126 0.125 0.116 0.114 0.113 0.113 0.103 0.102 0.101
〃 2 450 0.131 0.115 0.112 0.107 0.107 0.099 0.105 0.102 0.102-
３ 3 450 0.113 0.110 0.106 0.105 0.103 0.097 0.095 0.100 0.100-
４ 4 450 0.135 0.130 0.115 0.109 0.105 0.103 0.100 0.099 0.098-
450 5 450 0.217 0.209 0.190 0.173 0.160 0.152 0.151 0.150 0.149-
６ 6> 500 0.149 0.124 0.119 0.116 0.114 0.110 0.108 0.107 0.106 0.104
〃 7> 500 0.125 0.117 0.115 0.111 0.107 0.103 0.101 0.100 0.100 0.098
８ 8> 500 0.130 0.112 0.107 0.105 0.102 0.100 0.099 0.098 0.098 0.098
９ 9 450 0.127 0.108 0.105 0.103 0.101 0.100 0.100 0.099 0.099-
〃 10> 500 0.143 0.129 0.118 0.115 0.111 0.108 0.105 0.103 0.101 0.101
〃 11> 500 0.125 0.107 0.101 0.096 0.094 0.094 0.093 0.093 0.093 0.092
Comparative Example 5 300 0.153 0.140 0.145 0.141 0.143 0.147----
〃 6 300 0.287 0.229 0.190 0.185 0.177 0.169----
〃 7> 500 0.166 0.153 0.149 0.144 0.140 0.137 0.135 0.133 0.132 0.131
Note) In Comparative Examples 5 to 7, the ratio of 12-hydroxystearic acid salt to the solid lubricant was high, and the effect of the solid lubricant was not exhibited.

  Lubricating oil compositions according to the present invention include sintered oil-impregnated bearings, fluid bearings, hydrodynamic bearings, bushes, sintered bushes, as well as general rolling bearings, thrust bearings, hydrodynamic bearings, resin bearings, linear motion devices, etc. Power transmission devices such as bearings, reducers / speed increasers, gears, chains, motors, vacuum pumps, valves, seal pneumatic machines, hydraulic operating parts, machine tools such as electric tools, and parts for office equipment such as LBP scanner motors PC / HDD related parts such as fan motors, spindle motors, contacts, parts used for home appliance precision equipment such as VTR capstan motors, mobile phone vibration motors, metal processing equipment, transport equipment, railways, ships, aviation Various parts, automotive accessories (engine parts such as fuel pumps, intake / fuel parts such as electronic control throttles, exhaust system parts such as exhaust gas circulation devices, cooling system parts such as water pumps) Air conditioning system parts such as air conditioners, traveling system parts, braking system parts such as ABS, steering system parts, drive system parts such as transmissions, power windows, interior and exterior system parts such as optical axis adjustment motors for headlights and door mirror motors Etc.), food / pharmaceutical industry, steel, construction, glass industry, cement industry, film tenter and other chemical / rubber / resin industry, environment / power equipment, paper / printing industry, wood industry, textile / apparel industry, relative parts It is effectively used as oil for parts such as moving machine parts and internal combustion engines.

Claims (5)

An amount of 0.1 to 5% by weight of a solid lubricant, which is a polytetrafluoroethylene resin , contained in a base oil made of synthetic oil, and a weight ratio of 0.10 to 0.50 with respect to the amount of solid lubricant A lubricating oil composition comprising a lithium-based soap, a lithium-based composite soap or a urea-based compound.   The lubricating oil composition according to claim 1, wherein the synthetic oil is at least one of a synthetic hydrocarbon oil, an ester-based synthetic oil and a glycol oil. The lubricating oil composition according to claim 1, wherein a base oil having a kinematic viscosity at 40 ° C of 20 to 800 mm ² / sec is used. 4. The lubricating oil composition according to claim 3, wherein a base oil having a kinematic viscosity at 40 [deg.] C. of 20 to 250 mm < ² > / sec is used for bearings and bushes. The lubricating oil composition according to claim 3, wherein a base oil having a kinematic viscosity at 40 ° C of 100 to 800 mm ² / sec is used for chain oil or gear oil applications.