WO2006059687A1

WO2006059687A1 - Bearing lubricant

Info

Publication number: WO2006059687A1
Application number: PCT/JP2005/022099
Authority: WO
Inventors: Satoshi Hiyoshi; Satoshi Moriyama; Iwao Hotta; Toshio Yamauchi
Original assignee: Kyowa Hakko Chemical Co., Ltd.
Priority date: 2004-12-01
Filing date: 2005-12-01
Publication date: 2006-06-08
Also published as: JPWO2006059687A1

Abstract

Disclosed is a bearing lubricant characterized by containing a dibasic acid diester represented by the general formula (I) below (wherein R2 and R3 may be the same as or different from each other and respectively represent a lower alkyl, R1 and R4 may be the same as or different from each other and respectively represent a straight-chain alkyl, and n represents an integer of 1-3). In the above general formula (I), it is preferable that R1 and R4 may be the same as or different from each other and respectively represent a straight-chain alkyl having 6-10 carbon atoms, R2 and R3 may be the same as or different from each other and respectively represent a methyl or an ethyl, and n is 1 or 2. The bearing lubricant has low viscosity over a wide temperature range and is excellent in low-temperature fluidity, heat resistance and the like.

Description

Specification

Bearing lubricant

Technical field

[0001] The present invention relates to a bearing lubricating oil containing a dibasic acid diester.

Background art

[0002] Automobiles, industrial machines, information devices, home appliances, and the like are designed to save energy. The bearing lubricants and greases used in these machines are also strongly required to save energy and energy as energy savings. An important element of energy conservation from bearing lubricants is to reduce the viscosity of bearing lubricants. A major problem in achieving low viscosity is the lack of heat resistance, since the molecular weight is lower than that of conventional base oils, resulting in increased evaporation loss. Because of this problem, there was a limit to reducing the viscosity of bearing lubricants.

[0003] Currently, dibasic acid diester type is widely used as bearing lubricant, and for example, 2-ethylhexyl ester (DOS) of sebacic acid (see, for example, Patent Document 1) is disclosed. . Similarly, a polyol ester type lubricating oil for bearings is also used. For example, dioctyl ester of 2,4-jetyl-1,5-pentanediol (for example, JP-A-2003-321691) is disclosed. ing.

[0004] However, the lubricating oil in which the above-mentioned misaligned ester is a base oil also has satisfactory performance as a lubricating oil for bearings that does not sufficiently satisfy properties such as low viscosity and heat resistance. There was no.

In addition, a lubricant containing a 2,4-dialkyldaltaric acid diester is disclosed. An example of use as a lubricant for a force bearing is not specifically disclosed (for example, see Patent Document 2).

Patent Document 1: Japanese Patent Laid-Open No. 2002-097482

Patent Document 2: International Publication No. 03Z33451

Disclosure of the invention

Problems to be solved by the invention [0005] An object of the present invention is to provide a lubricating oil for a bearing having a low viscosity over a wide temperature range and excellent in low-temperature fluidity and heat resistance.

Means for solving the problem

[0006] The present invention provides the following (1) to (3).

(1) General formula (I)

[0007] [Chemical 1]

(I)

[0008] (wherein R ² and R ³ are the same or different and represent lower alkyl, R ¹ and R ⁴ are the same or different and represent linear alkyl, and n represents an integer of 1 to 3) A bearing lubricating oil comprising a dibasic acid diester represented by the formula:

(2) and R ⁴ are the same or different and linear alkyl having 6 to 10 carbon atoms, R ² and R ³ are the same or different and are methyl or ethyl, and n is 1 or 2. 1. The bearing lubricant according to 1.

(3) The 1 ^ and R ⁴ forces are the same or different and are heptyl, octyl or norm, R ² and R ³ are both ethyl, and n is 1.

Hereinafter, the dibasic acid diester represented by the general formula (I) may be expressed as a compound (I).

The invention's effect

The present invention provides a lubricating oil for bearings that has a low viscosity over a wide temperature range and is excellent in low-temperature fluidity and heat resistance.

BEST MODE FOR CARRYING OUT THE INVENTION

In the definition of each group of general formula (I), examples of lower alkyl include linear or branched alkyl having 1 to 8 carbon atoms, and more specifically, methyl, ethyl, Propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, iso Examples include pentinole, neopentyl, tert pentyl, hexyl, heptyl, octinole, isooctyl, 2-ethylhexyl and the like. In R ² and R ³ , methyl or ethyl is preferred, and ethyl is more preferred.

[0012] Examples of the straight chain alkyl include straight chain alkyls having 2 to 40 carbon atoms, and more specific examples include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, Nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl (stearyl), nonadecyl, eicosyl, docosyl, triacontyl, tetracontyl, etc. More preferred are heptyl, octyl, and nor.

[0013] The compound (I) comprises a corresponding dibasic acid and 1 to 10 equivalents, preferably 1 to 2 equivalents of an aliphatic alcohol, optionally in the presence of an azeotropic agent and a catalyst. It can be obtained by reacting at 180 ° C. Examples of the azeotropic agent include toluene, benzene and the like, and these are usually used in an amount of 0.5 to LOO equivalent to the corresponding dibasic acid. Examples of the catalyst include a condensing agent such as p-toluenesulfonic acid, an organic titanium compound or carpositimide, and these are usually 0.001 to 5 equivalents to the corresponding dibasic acid. Used.

[0014] The corresponding dibasic acid is, for example, in accordance with a known method (for example, “Oka Chemical, 19 卷, No. 12, page 1087 (1970)”, JP-A-6-72948, etc.) The corresponding diol can be produced by treatment in the presence of 1 to 5 equivalents of a base such as sodium hydroxide or potassium hydroxide, preferably at 200 to 320 ° C. At this time, a reaction solvent such as an ether solvent such as dibenzyl ether or a hydrocarbon solvent such as liquid paraffin (carbon number 10 to 16) may be used.

[0015] Further, the corresponding diol can be produced according to a known method (WO97Z19904 or the like).

The bearing lubricating oil of the present invention preferably contains 10% by weight or more of compound (I), more preferably 25% by weight or more based on the total weight. It is more preferable to contain 50% by weight or more.

[0016] The bearing lubricating oil of the present invention may contain ester oil, polyocorephin, mineral, if necessary. Other base oils such as physical oils and silicone oils may be contained.

Examples of ester oils include fatty acid monoesters, adipic acid diesters, pimelic acid diesters, suberic acid diesters, azelaic acid diesters, sebacic acid diesters, phthalic acid diesters, and polyol polyesters.

[0017] Examples of poly (X-olefin include low molecular weight polybutene, low molecular weight polypropylene, and a-olefin oligomer having 8 to 14 carbon atoms.

Examples of the mineral oil include paraffin-based crude oil, intermediate-based crude oil, and naphthene-based crude oil.

The amount of other base oils such as ester oil, poly-α-olefin, mineral oil, silicone oil and the like is not particularly limited, but is preferably 90% by weight or less based on Compound (I). Is more preferably 50% by weight or less.

[0018] The bearing lubricating oil of the present invention includes a cleaning dispersant, an antioxidant, an extreme pressure agent, a friction modifier, an oily agent, an antifungal agent, a gas phase antifungal agent, and a pour point depressing agent as necessary. It can be obtained by adding additives such as agents, thickeners, preservatives, antifoaming agents, demulsifiers, extreme pressure additives, dyes and fragrances. The addition amount of these additives is not particularly limited, but is preferably 0.001 to 5% by weight in the bearing lubricating oil of the present invention.

[0019] The bearing lubricating oil of the present invention exhibits low viscosity over a wide temperature range, is excellent in lubricity, low-temperature fluidity, heat resistance, and has a long life.

The bearing lubricating oil of the present invention includes, for example, engine oil, automatic transmission oil, continuously variable transmission oil, gear oil, power steering oil, shock absorber oil, turbine oil, hydraulic oil, refrigerating machine oil, rolling oil, bearing oil. It can also be used as grease, lubricating oil for metal processing, and the like.

[0020] Engine oil means four-cycle gasoline engines for automobiles, motorcycles, trains, ships, submarines, etc., two-cycle gasoline engines, sliding parts of piston rings and cylinders of diesel engines, connecting rods and crankshaft bearings, cams It is a lubricating oil used for lubrication of valve system parts of valve lifters.

The automatic transmission oil is a lubricating oil that is used for power transmission, wear adjustment, and lubrication of various gears, which are a hydraulic transmission that controls a fluid transmission, a gear device, a wet clutch, and a hydraulic mechanism. [0021] The continuously variable transmission oil is a lubricating oil used for a continuously variable transmission. There are two types of continuously variable transmissions: belt drive type and traction drive type, which are used as transmissions for automobiles, machine tools, industrial machines, etc. A belt-driven continuously variable transmission consists of two pulleys on the engine side and drive wheel side, and a belt hung between them. Lubricating oil is used for lubrication and hydraulic operation of the belt, clutch plate, and hydraulic system. Traction drive type continuously variable transmissions are designed to transmit torque between rolling elements via an oil film, and lubricating oil is used to transmit torque, prevent burning of the rolling elements, and wear.

[0022] The power steering oil is a lubricating oil used in the power steering device for the purpose of reducing the force applied to the steering wheel.

Shock absorber oil is lubricating oil used for shock absorbers in suspension devices for the purpose of providing maneuverability, stability and ride comfort.

Turbine oil is lubricating oil used to lubricate turbine bearings and reduction gears, and is used in steam turbines, gas turbines, nuclear turbines, etc. for generators, ships and aircraft.

[0023] Hydraulic oil is lubricating oil used to lubricate sliding parts of hydraulic equipment and devices, such as construction machinery, machine tools, metal and plastic processing machines, vehicles, ships, aircraft, etc. Used for hydraulic equipment and devices.

Refrigerating machine oil is a lubricating oil that is used in the presence of coexistence with refrigerants in a compressor of a refrigerator, and is used in refrigerators for air conditioning, refrigerators, freezing and refrigeration for food processing and distribution, industrial use, etc.

[0024] The rolling oil is a lubricating oil used for the purpose of imparting lubricity to an excessively-rubbed portion between the material and the roll when rolling a metal material such as steel or an aluminum alloy.

Grease is a semi-solid or solid dispersion of an increasing agent in lubricating oil. For automobiles, wheel bearings, constant velocity ball joints, universal joints, propeller shaft center supports, clutch release bearings, For water pump bearings, steering and accelerator linkage mechanisms, electrical equipment bearings, propeller shaft splines, instrument wire cables, wind regulators, body parts such as door mirrors, brake parts, etc. Used for industrial purposes, rolling and plain bearings, gears and chains It is used for devices having joints such as screens and machine sliding surfaces.

[0025] The metal processing lubricant is a lubricant used for lubrication and cooling by the mechanical force of the metal. There are various types such as a cutting fluid, a rolling fluid, a pressing lubricant, and a drawing fluid.

The application of the bearing oil or grease using the bearing lubricant of the present invention is not particularly limited, but an electronic device having a drive motor, such as a hard disk, a convection fan, a mobile phone, a laser printer, a digital Copiers, laser platemakers, measuring instruments, barcode readers, and other devices that require rotating devices such as magnetic disks, optical disks, flexible disks, mini disks, compact disks, laser disks, DVDs, Blu-ray discs, digital Playing, recording, recording, recording device for video, video tape, etc., household appliances having a drive motor, for example, refrigerator, microwave oven, vacuum cleaner, washing machine, dryer, electric fan, air conditioner, shaver, etc. Precision machinery such as watches, cameras, turbine generators, compressors, Roaming machines, robots, radars, artificial satellites, space stations, etc. Toys with motors for driving, such as remote controllers, radio-controlled devices, etc., transportation equipment, such as (electric) cars, trains, ships, submarines, airplanes, rockets, etc. Medical equipment with motors for use such as pumps for artificial hearts, pumps for artificial dialysis, handpieces, medical beds, nursing beds, electric wheelchairs, massage chairs, etc. Can do.

[0026] Hereinafter, the present invention will be described more specifically with reference to Examples and Reference Examples.

The measurement data in the examples and test examples were obtained by the following measuring instruments and measuring methods. Infrared spectrum (IR): FTS—40A (manufactured by Nippon Bio-Rad)

Nuclear magnetic resonance spectra ('Η-NMR, ¹³ C-NMR; using tetramethylsilane as standard): GSX—400 (400 MHz)

Kinematic viscosity: Using a Canon-Fenske viscometer, it was measured under the temperature conditions of 40 ° C and 100 ° C according to the method defined in (JIS K2283). The kinematic viscosity at 0 ° C was calculated using the viscosity index.

The pour point was measured by the method defined in (JIS K2269).

For heat resistance, 2 g of the samples listed in the Examples and Comparative Examples were placed in a 50 mL beaker and weighed before and after heating in a 150 ° C oven for 24 hours. (Weight before heating Weight after heating Amount) Calculated by weight X before Z heating X 100.

Example 1

[0027] Synthesis of Diheptyl 2, 4-Jetyldaltalate (Compound 1)

2, 4-Jetyldartaric acid (539.6 g, manufactured by Kyowa Hakko Chemical Co., Ltd.) and heptanol (799.2 g, manufactured by Wako Pure Chemical Industries, Ltd.) were placed in a reaction flask, stirred well, and p-toluenesulfonic acid 1 water Japanese 5.4 g (manufactured by Kyowa Hakko Chemical) was added and refluxed for 5 hours. After cooling to room temperature, neutralizing with 10 wt% sodium hydroxide aqueous solution and washing with water, unreacted alcohol was distilled off at 180 ° C under reduced pressure, followed by distillation at 240 ° C under reduced pressure. Purification gave 943 g (yield: 85.6%) of the compound. The physical property values of this compound were as follows.

— NMR (CDC1, 6 ppm); 0. 89 (t, 12H), 1. 29 (m, 16H), 1. 50— 1.98 (

Three

m, 10H), 2.30 (m, 2H), 4.07 (m, 4H)

¹³ C-NMR (CDC1, 6 ppm); 11. 5, 11. 6, 14. 1, 22. 6, 25. 2, 25. 9, 26. 4

Three

, 28. 7, 28. 8, 28. 9, 31. 8, 33. 6, 34. 6, 44. 9, 45. 5, 64. 3, 64. 4, 175. 7, 175. 9

IR (KBr Neat; cm " ¹ ); 2960, 2931, 2873, 2858 (CH), 1735 (C = 0), 14 61, 1382, 1267, 1167 (C-0)

Example 2

[0028] Synthesis of Dioctyl 2, 4-Jetyldartalate (Compound 2)

2, 4-—Jetyldartaric acid 547. Og (manufactured by Kyowa Hakko Chemical Co., Ltd.) and Octanol 911.4 g (manufactured by Wako Pure Chemical Industries, Ltd.) were placed in a reaction flask and stirred well, then p-toluenesulfonic acid monohydrate 5.5 g ( Kyowa Hakko Chemical) was refluxed for 5 hours. The reaction solution was cooled to room temperature, neutralized with a 10% by weight aqueous sodium hydroxide solution, washed with water, and unreacted alcohol was distilled off at 190 ° C under reduced pressure, followed by distillation at 250 ° C under reduced pressure. Purification gave 1002 g (yield: 84.0%) of compound 2. The physical property values of Compound 2 were as follows.

— NMR (CDC1, 6 ppm); 0. 89 (t, 12H), 1. 28 (m, 20H), 1. 50— 1.98 (

Three

m, 10H), 2.30 (m, 2H), 4.07 (m, 4H)

¹³ C-NMR (CDC1, 6 ppm); 11. 5, 11. 6, 14. 1, 22. 7, 25. 2, 26. 0, 26.4

Three

, 28. 7, 28. 8, 29. 3, 31. 8, 33. 6, 34. 3, 44. 9, 45. 5, 64. 3, 64. 4, 175 . 7, 175. 9

IR (KBr Neat; cm ^_1 ); 2959, 2929, 2872, 2857 (C— H), 1735 (C = 0), 14 61, 1382, 1266, 1167 (C-0)

Example 3

[0029] Synthesis of dinonyl 2,4-jetyldaltalate (compound 3)

2,4—Jetyldartaric acid 540.2 g (manufactured by Kyowa Hakko Chemical) and nonanol 993.6 g (manufactured by Wako Pure Chemical Industries, Ltd.) were charged into a reaction flask and stirred well, and then p-toluenesulfonic acid monohydrate 5.5 g ( Kyowa Hakko Chemical) was refluxed for 5 hours. The reaction solution was cooled to room temperature, neutralized with a 10% by weight aqueous sodium hydroxide solution and washed with water. Unreacted alcohol was distilled off at 200 ° C under reduced pressure, and then distilled and purified at 260 ° C under reduced pressure. Compound 10 (1095 g, yield: 86.6%) was obtained. The physical property values of Compound 3 were as follows.

— NMR (CDC1, 6 ppm); 0. 89 (t, 12H), 1. 30 (m, 24H), 1. 50—1. 99 (

Three

m, 10H), 2.30 (m, 2H), 4.07 (m, 4H)

¹³ C-NMR (CDC1, 6 ppm); 11. 5, 11. 6, 14. 1, 14. 1, 22. 7, 25. 2, 26. 0

Three

, 26. 4, 28. 7, 28. 8, 29. 3, 31. 9, 33. 7, 34. 3, 44. 9, 45. 5, 64. 4, 64. 4, 175. 6, 175 . 9

IR (KBr Neat; cm ^_1 ); 2959, 2927, 2856 (CH), 1735 (C = 0), 1461, 13 82, 1267, 1166 (C-0)

Example 4

[0030] Synthesis of a mixture of heptyloctyl 2,4-jetyldaltalate and diheptyl 2,4-jetyldartalate and dioctyl 2,4-jetyldaltarate (compound 4)

2,4-Jetyldartaric acid 583. lg (manufactured by Kyowa Hakko Chemical), heptanol 650.7 g (manufactured by Wako Pure Chemical Industries), octanol 247.4 g (manufactured by Wako Pure Chemical Industries) were charged into the reaction flask and stirred well, p-Toluenesulfonic acid monohydrate (5.8 g, manufactured by Kyowa Hakko Chemical) was added and refluxed for 4 hours. The reaction solution was cooled to room temperature, neutralized with 10% by weight aqueous sodium hydroxide and washed with water, and unreacted alcohol was distilled off at 190 ° C under reduced pressure, followed by distillation at 240 ° C under reduced pressure. As a result, 1068 g (yield: 87.6%) of compound 4 was obtained. The physical properties of compound 4 are It was as follows.

— NMR (CDC1, 6ppm); 0.89 (t, 12H), 1.30 (m, 18H), 1.50—1.98 (

Three

m, 10H), 2.29 (m, 2H), 4.09 (m, 4H)

¹³ C-NMR (CDC1, 6 ppm); 11.5, 11.6, 14.1, 22.6, 22.7, 25.2, 25.9

Three

, 26.0, 26.4, 28.7, 28.8, 29.0, 29.3, 31.8, 31.9, 33.7, 34.3, 44. 9, 45.2, 64.3, 64.4, 175.6, 175.9

IR (KBr Neat; cm '' ¹ ); 2960, 2930, 2873, 2858 (CH), 1735 (C = 0), 14 61, 1382, 1266, 1167 (C-0)

Example 5

Synthesis of noroctyl 2,4-jetyldartalate and dioctyl 2,4-jetyldaltarate and 2,4-jetyldallate dinolate (compound 5)

2,4-Jetyldartalic acid 550.3g (manufactured by Kyowa Hakko Chemical), octanol 456.9g (manufactured by Wako Pure Chemical Industries), and nonanol 506.lg (manufactured by Wako Pure Chemical Industries) were charged into the reaction flask and stirred well. —Toluenesulfonic acid monohydrate 5.6 g (manufactured by Kyowa Hakko Chemical) was added and refluxed for 4 hours. Cool to room temperature, neutralize with 10 wt% sodium hydroxide aqueous solution, wash away the unreacted alcohol from the reaction solution washed with water at 190 ° C under reduced pressure, and then at 240 ° C under reduced pressure. Distillation yielded 1116 g of compound 5, yield (89.5%). The physical properties of compound 5 were as follows.

— NMR (CDC1, 6ppm); 0.89 (t, 12H), 1.28 (m, 22H), 1.50—1.98 (

Three

m, 10H), 2.28 (m, 2H), 4.07 (m, 4H)

¹³ C-NMR (CDC1, 6 ppm); 11.6, 11.6, 14.1, 22.7, 25.2, 26.0, 26.4

Three

, 28.7, 28.8, 29.2, 29.3, 29.5, 31.8, 31.9, 33.6, 34.3, 44.9, 45. 5, 64.4, 64.4, 175.7, 175.9

IR (KBr Neat; cm ^_1 ); 2959, 2928, 2856 (CH), 1735 (C = 0), 1461, 13 82, 1266, 1166 (C-0)

Comparative Example 1: Synthesis of di (2-ethylhexyl) 2,4-deethyldaltalate (Compound 6)

2,4-Jetyldartalic acid 592. Og (Kyowa Hakko Chemical), 2-ethyl hexanol 901. Og (Kyowa Hakko Chemical) was charged into the reaction flask, stirred well, 5.8 g of ruenesulfonic acid monohydrate (manufactured by Kyowa Hakko Chemical) was added and refluxed for 5 hours. Cool to room temperature, neutralize with 10% by weight aqueous solution of sodium hydroxide and water, and remove unreacted alcohol at 190 ° C under reduced pressure from the reaction mixture, and then distill at 250 ° C under reduced pressure. Purification gave 1165 g of compound 6, yield (89.8%). The physical properties of Compound 6 were as follows: NMR (CDC1, 6ppm); 0.89 (m, 18H), 1.35 (m, 20H), 1.29— 1.41

Three

(m, 16H), 1.51-1.64 (m, 6H), 1.73— 1.95 (m, 2H), 2.30 (m, 2H), 4.04 (m, 4H)

¹³ C-NMR (CDC1, 6 ppm); 10.9, 11.0, 11.5, 11.6, 14.0, 23.0, 23.8

Three

, 23.9, 25. 1, 26.4, 28.9, 30.4, 30.5, 33.6, 34.2, 38.8, 44.9, 45. 7, 66.4, 66.5, 175.7, 175.9

IR (KBr Neat; cm ^_1 ); 2962, 2932, 2875, 2861 (C—H), 1734 (C = 0), 14 62, 1382, 1267, 1169 (C-0)

Comparative Example 2: Synthesis of 2,4-Dethyldaltalic acid di (3,5,5-trimethylhexyl) (Compound 7)

2, 4--Jetyldartaric acid 565. Og (manufactured by Kyowa Hakko Chemical), 3, 5, 5-trimethylhexanol 953. Og (manufactured by Kyowa Hakko Chemical) was charged into the reaction flask, stirred well, and then p-toluenesulfonic acid Monohydrate 6. lg (manufactured by Kyowa Hakko Chemical) was refluxed for 5 hours. Cool to room temperature, neutralize with 10 wt% sodium hydroxide aqueous solution and wash with water. Unreacted alcohol is distilled off at 200 ° C under reduced pressure, followed by distillation at 260 ° C under reduced pressure. The product was purified to obtain 1124 g (yield: 90.7%) of Compound 7. The physical properties of compound 7 were as follows.

— NMR (CDC1, 6ppm); 0.82— 0.96 (m, 30H), 1.06— 1.26 (m, 4H)

Three

, 1.45-1.76 (m, 12H), 2.31 (m, 2H), 4.09 (m, 4H)

¹³ C-NMR (CDC1, 6 ppm); 11.5, 11.6, 22.4, 22.5, 25.0, 26.2, 26.3

Three

, 26.3, 27.2, 29.9, 31.0, 33.5, 34.1, 37.9, 38.0, 44.8, 45.4, 45. 5, 51.0, 51. 1, 62.7, 175.5, 175.7

IR (KBr Neat; cm ^_1 ); 2958, 2907, 2870 (C— H), 1734 (C = 0), 1463, 13 65, 1268, 1167 (C-0)

Test example 1

Compounds 1 to 5 obtained in Examples 1 to 5 and Compound 6 7 obtained in Comparative Example 1 2 and Compound 8 (di-2-ethylhexyl sebacate) (manufactured by Wako Pure Chemical Industries) as Comparative Example 3 Tables 1 and 2 show the results of kinematic viscosity, viscosity index, pour point, and heat resistance test.

[0032] [Table 1] Table 1

[0033] [Table 2] Table 2

Compound 2 (dioctyl ester) has a low viscosity and excellent heat resistance as compared with compound 6 [di (2-ethylhexyl) ester]. Compound 3 (dinol ester) Compared with compound 7 [di (3,5,5-trimethylhexyl) ester], it has low viscosity and excellent heat resistance. Therefore, the composites obtained in Examples 1 to 5 are suitable for bearing lubricating oil applications.

Industrial applicability

Claims

The scope of the claims

[1] General formula (I)

[Chemical 2]

(Wherein IT and R ° are the same or different and represent lower alkyl, R ¹ and R are the same or different and represent linear alkyl, and n represents an integer of 1 to 3) A bearing lubricating oil comprising a basic acid diester.

[2] Claims in which R ¹ and R ⁴ are the same or different, straight-chain alkyl having 6 to 10 carbon atoms, and R ³ is the same or different, methyl or ethyl, and n is 1 or 2. Item 1. The lubricating oil for bearings according to Item 1.

[3] The bearing lubricating oil according to claim 1, wherein R ¹ and R ⁴ are the same or different and are heptyl, octyl or nor, R ² and R ³ are both ethyl, and n is 1. .