JPH0323592B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD This invention relates to lubricant compositions. Naphthenic hydrocarbon oils are used as base oils for lubricants for mechanical equipment, industrial hydraulic equipment, gear reduction gears, and the like. With the development of mechanical devices that use lubricants,
In order for these mechanisms to function effectively, it is not only necessary to select an appropriate lubricant, but also a lubricant with high performance is required. Ordinary lubricants are mainly composed of lubricating oil produced from petroleum oil. However, it is well known that such mineral oils, even if refined, do not have the performance to function satisfactorily under severe conditions.
Therefore, it is common practice to add small amounts of additives to such lubricating oils to improve their performance. However, even though the addition of additives improves some performance, it can lead to other problems such as increased corrosion, increased sludge production, etc.
It is difficult to provide sufficient performance only by adding additives. The life of a lubricant is determined by the increase in viscosity, corrosion of metals in contact, and the amount of sludge generated. As the operating conditions of modern mechanical devices have become more severe, there has been a particular demand for long lifespans. Since these deterioration phenomena are substantially caused by oxidation, oxidation stability has become a particularly important issue. Therefore, antioxidants are added to modern lubricants. However, even when antioxidants are added, oxidation progresses over time when used under harsh conditions and subjected to heat and oxidative stress. The present inventors have recognized that naphthenic hydrocarbon oil has excellent performance as a lubricating oil for mechanical equipment, hydraulic fluid, gear oil, etc., and have conducted various studies on lubricant compositions with improved oxidation stability. The present invention was developed based on the recognition that a base oil containing a specific naphthenic hydrocarbon having three hydrogenated six-membered carbon rings has excellent lubricant properties and oxidation stability. That is, the present invention is based on the general formula (However, in the formula, R ¹ is an alkylene group having 1 to 3 carbon atoms, R ³ , R ⁴ and R ⁵ are each independently an alkyl group having 1 to 3 carbon atoms, and l, m and n are 0 to 3 carbon atoms. an integer of 3, x is 0 or 1. This is a lubricant composition with special characteristics. The compounds represented by the general formula include those represented by the following general formulas () and (). R ¹ is an alkyl-substituted alkylene group having 1 to 3 carbon atoms or a linear alkylene group, preferably a methylene group, an ethylene group, or a methyl-substituted methylene group. R ³ , R ⁴ and R ⁵ are alkyl groups having 1 to 3 carbon atoms which may be the same or different, preferably a methyl group or an ethyl group.
l, m and n are integers of 0 to 3, preferably 0 or 1. Also, the total number of carbons is 19~
30, preferably 19-24, more preferably 19-22. Among the compounds represented by the above general formula (), hydrogenated dibenzyltoluene, hydrogenated (benzylphenyl)phenylethane, or one to
Two methyl or ethyl substituents are preferred and among the compounds of general formula () hydrogenated benzylbiphenyl or
Two methyl or ethyl substitutions are suitable and preferred for the purposes of this invention. Examples of suitable compounds include hydrogenated dibenzyltoluene, hydrogenated 1,1-(benzylphenyl)
Phenylethane, hydrogenated 1,1-(benzyltolyl)phenylethane, hydrogenated benzylbiphenyl, hydrogenated 1,1-(biphenylyl)phenylethane, hydrogenated (ethylbiphenylyl)phenylmethane, hydrogenated 1,1-(ethylbiphenyl) enylyl)phenylethane, hydrogenated (biphenylyl)tolylmethane, and the like. These compounds, such as hydrogenated dibenzyltoluene, can be obtained by hydrogenating dibenzyltoluene obtained by reacting a halogenated benzyl and toluene in the presence of a Friedel-Crafts catalyst. In addition, hydrogenated dibenzylbiphenyl is
It is obtained by hydrogenating dibenzylbiphenyl obtained by reacting benzyl halide and biphenyl in the presence of a Friedel-Crafts catalyst. The compounds obtained in this way are mixtures of isomers and, depending on the hydrogenation conditions, also mixtures with partially hydrogenated products. however,
Not only is it difficult to separate only specific compounds from these mixtures, but in many cases, the mixture also performs well for the purpose of the present invention, so separation is not necessary. In that sense, the hydrogenation rate does not need to be completely 100%.
% or more, preferably 90% or more is sufficient. Furthermore, the compound used in the present invention has a pour point of 0.
℃ or less, flash point is 120℃ or more, and aniline point is
A temperature of 70°C or higher is preferable, and such a compound exhibits good performance when used as a base oil for lubricants such as hydraulic fluids. Furthermore, the compound used in the present invention must have oxidation stability above a certain level, and the test results of JISK2514-1980 are based on the viscosity ratio,
Increase in total acid value (mg KOH/g) and n-heptane insoluble content (wt%) are 1.2 or less and 0.3, respectively.
and less than or equal to 0.3, and ASTM
The oxidation life specified in D2272-67 is 250 minutes or more,
Preferably it is 300 minutes or more. The oxidation test is carried out on samples to which 0.5% by weight each of 2,6-di-t-butyl para-cresol and zinc dialkyldithiophosphate are added. Oxidation test conditions

[Table] Oxidation catalyst Copper and iron Copper and iron
Additives are added to the compound represented by the general formula to form a lubricant composition. As the additive, one or more known additives such as an antioxidant, a dispersant, a viscosity index improver, an antiwear agent, a rust inhibitor, a corrosion inhibitor, or an antifoaming agent are used. In addition, a small amount of mineral oil or naphthenic oil such as alkylcyclohexane may be added as a diluent. In particular, carbon number 9~
20 alkylcyclohexane to the compound of the present invention
It can also be added in an amount of 100 parts by weight or less per 100 parts by weight. The lubricant composition of the present invention does not contain a grease composition and is selected from the group consisting of lubricants other than power transmission lubricants, namely dynamo oil, turbine oil, machine oil, bearing oil and industrial gear oil. It can be used as at least one lubricant. The lubricant composition of the present invention has the characteristics resulting from the fact that its base oil is a naphthenic hydrocarbon, has high oxidation stability, and can be used for a long period of time under severe conditions. Next, the present invention will be explained in more detail with reference to Examples. In addition, "part" in the following examples,
Based on weight unless otherwise specified. Example 1 0.002 to 0.01 aluminum chloride in 3 parts of toluene
1 part of benzyl chloride, heated to 70℃, and then added 1 part of benzyl chloride.
1 part was added and reacted for 2 hours. The reaction product was washed with water to remove the catalyst, and then distilled to separate unreacted substances. The obtained dibenzyltoluene (m->p
->o-isomer mixture) was supplied to an autoclave, and an initial hydrogen pressure of 40 Kg/cm ² G was applied using a nickel catalyst.
A hydrogenation reaction was carried out at a temperature of 200° C. for 4 hours to obtain hydrogenated dibenzyltoluene (isomer mixture). A lubricant composition was prepared by adding 0.5% by weight each of 2,6-ditertiarybutyl p-cresol and zinc dialkyldithiophosphate as antioxidants to the hydrogenated naphthenic hydrocarbon. An oxidation test was conducted on this lubricant composition under the conditions described above. In addition, oxidation tests were conducted in the same manner for the Examples following Example 2. For comparison, a similar test was also conducted on a lubricant composition prepared from naphthenic mineral oil. The properties and test results of the hydrogenated naphthenic hydrocarbons are shown in Tables 1 and 2, respectively, along with other examples. Example 2 0.001 to 0.005 mol of aluminum chloride was added to 4 mol of 1,1-diphenylethane, heated to 60°C, and then 1 mol of benzyl chloride was added and reacted for 20 minutes. Next, the reaction product was washed with water to remove the catalyst, and then distilled to separate unreacted substances. The obtained 1,1-(benzylphenyl)phenylethane (isomer mixture) was fed into an autoclave and heated to an initial hydrogen pressure of 100 Kg/cm ² G and temperature using a nickel catalyst.
Hydrogenation reaction was carried out at 140-170°C for 5 hours to obtain hydrogenated 1,1-(benzylphenyl)phenylethane (isomer mixture). Example 3 Hydrogenated monoethyl-substituted 1,1-(benzylphenyl) was prepared in the same manner as in Example 2, except that 4 moles of monoethyl-substituted 1,1-diphenylethane was used instead of 1,2-diphenylethane. Phenylethane ( and A mixture of The general properties of this product were as shown in Table 2. Table 2 shows the oxidation test results of a lubricant composition prepared by adding the same additives as in Example 1. Example 4 One portion of methyldiphenylmethane and 200 ml of concentrated sulfuric acid were fed into a reactor and maintained at 15°C. Then, 800 ml of a 1:1 mixture of methyldiphenylmethane and styrene was added dropwise over a period of 2-3 hours, during which time the temperature of the reaction solution was maintained at 15-20°C. After the dropwise addition was completed, 200 ml of concentrated sulfuric acid was added and the reaction was maintained for 30 minutes. The reaction product was then washed repeatedly with water to remove sulfuric acid, and the monomethyl-substituted 1,1-
(Benzylphenyl)phenylethane was obtained. Then, hydrogenated monomethyl-substituted 1,1-(benzylphenyl)phenylethane ( and A mixture of Example 5 5 parts of biphenyl and 0.001~ of aluminum chloride
0.005 part was added and heated to 60°C, then 1 part of benzyl chloride was added and reacted for 20 minutes. The reaction product was washed with water to remove the catalyst, and then distilled to separate unreacted substances. The obtained benzyl biphenyl (isomer mixture) was supplied to autoclave No. 1, and an initial hydrogen pressure of 100 Kg/1 was added using a nickel catalyst.
cm ² G, hydrogenated benzylbiphenyl (isomer mixture) by hydrogenation reaction for 2 hours at a temperature of 140-170°C.
I got it. Example 6 In Example 5, 5 parts of monoethylbiphenyl and 0.03 parts of aluminum chloride were used instead of biphenyl.
Hydrogenated benzylmonoethylbiphenyl (

[Formula] and A mixture of Example 7 A reactor was charged with 1 cyclohexylbenzene and 200 ml of concentrated sulfuric acid and kept at 15°C. Then, 800 ml of a 1:1 mixture of cyclohexylbenzene and styrene was added dropwise over a period of 2-3 hours, during which time the temperature of the reaction solution was maintained at 15-20°C. After the dropwise addition was completed, 200 ml of concentrated sulfuric acid was added and the reaction was continued for 30 minutes. The reaction product was then repeatedly washed with water to remove sulfuric acid, and 1,1-(cyclohexyl phenyl) phenylethane (isomer mixture) was obtained by distillation. Next, 1,1-(cyclohexylphenyl)phenylethane 1 was supplied to the autoclave, and the initial pressure of hydrogen was increased to 100 using a nickel catalyst.
A hydrogenation reaction was carried out at Kg/cm ² G and a temperature of 140 to 170° C. for 2 hours to obtain hydrogenated 1,1-biphenylyl)phenylethane (isomer mixture). Example 8 Same procedure as in Example 7 except that cyclohexylbenzene was replaced by monoethylbiphenyl 1 and 800 ml of a 1:1 mixture of monoethylbiphenyl and styrene was used instead of the mixture of cyclohexylbenzene and styrene. Hydrogenated 1,1-(ethylbiphenylyl)phenylethane ( and A mixture of Example 9 Methylbenzyl phenyl was obtained in the same manner as in Example 4, except that monomethylbenzyl chloride was used instead of benzyl chloride, the reaction temperature was 80°C, and the reaction time was 1 hour. . Example 10 Dodecylcycloxane 50 obtained by hydrogenating the reaction product of propylene tetramer and benzene
Additives were added in the same manner as in Example 1 to a mixture of 50 parts of hydrogenated dibenzyltoluene and 50 parts of hydrogenated dibenzyltoluene to obtain a lubricant composition. Example 11 A mixture and a lubricant composition were obtained in the same manner as in Example 10, except that hydrogenated benzylbiphenyl was mixed instead of hydrogenated dibenzyltoluene. Table 3 shows the general properties of the mixture, and Table 4 shows the oxidation test results of the lubricant composition.

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[Table] Depends.

Claims (1)

[Claims] 1. In a lubricant composition (excluding lubricant compositions for power transmission devices and grease compositions), the general formula (However, in the formula, R ¹ is an alkylene group having 1 to 3 carbon atoms, R ³ , R ⁴ and R ⁵ are each independently an alkyl group having 1 to 3 carbon atoms, and l, m and n are 0 to 3 carbon atoms. an integer of 3, x is 0 or 1. Characteristic lubricant compositions.