BRPI0720360B1 - lubricating oil composition, use of it, and method for improving lubrication - Google Patents

Description

"LUBRICANT OIL COMPOSITION, USE OF THE SAME, AND METHOD FOR IMPROVING LUBRICATION" The present invention provides lubricating oil compositions and, in particular, lubricating oil compositions used as machine oils, hydraulic oils, turbine oils, lubricating oils. compressor, gear oils, sliding friction oils. Corrosion resistance is required as a fundamental property of lubricating oils in machine installations in order to maintain performance. The temperature of the lubricating oil inside machine and appliance tanks rises and falls according to the conditions of use, and therefore the lubricating oil inside tanks may be subjected to mixing with condensed water or mixing with moisture because of cooling water pipe leaks. r It is also necessary to inhibit, as far as practicable, sediment generation in lubricating oils used in machine installations. If large amounts of sediment have been generated due to deterioration under heat, for example, blockage of oil filter screens may occur and sufficient supply of lubricating oil may not be possible, causing malfunctions. Also the generated sediment may accumulate in gear parts and a suitable oil film may not form because of the lacquer generated in the gear parts, causing gear malfunction. In addition, in hydraulic installations, sediment can block parts of the hydraulic circuit known as servo pumps, leading to plant malfunctions. Lubricating oil compositions with low sediment generation are therefore required.

In addition, in recent years good friction properties have been required of industrial lubricating oil compositions. This is because of the need to efficiently reduce friction losses in machines and appliances and achieve great energy savings by achieving a low coefficient of friction (μ). In addition, hydraulic apparatus is widely employed in construction machinery and so on, and if the coefficient of friction of the lubricating oils used for the lubricating oil driving machinery is high, the tiny grip-slip phenomenon may occur on the frictional parts. sliding of the hydraulic cylinder seal, and chattering, vibration, squealing and other abnormal sounds can occur in the cylinders, so it is impossible to control the hydraulic plant with satisfactory precision. See Japanese Patent Open to the Public 9-111277 (1997). It is therefore necessary to reduce the friction coefficient of the lubricating oil so that the hydraulic cylinders move smoothly and accurately. The present invention aims to obtain a lubricating oil composition having superior corrosion resistance properties as well as producing only small amounts of sediment. However, anti-corrosives added to improve corrosion resistance may be substances that give rise to sediment as a result of deterioration under heat. An important problem, therefore, is striking a balance between maintaining the anti-corrosive effect and inhibiting sedimentation.

Other major problems are reducing the friction coefficients of lubricating oils and achieving industrial lubricating oils having high energy savings. If a lubricating oil composition that solves these problems is employed for the hydraulic oils of the hydraulic apparatus, the phenomena of chattering, vibration, hoisting and other abnormal noises will not occur in the hydraulic cylinders and it will be possible to control the hydraulic apparatus satisfactorily. precision. The present invention aims at obtaining a lubricating oil composition which inhibits corrosion and sedimentation generation, which has abundant energy saving properties and which has good operational efficiency.

To this end, the present invention provides a suitable lubricating oil composition as an industrial lubricating oil, such as a hydraulic oil, by the addition of an aspartic acid derivative and an epoxidized ester compound as an additive to a base oil, preferably being a highly refined base oil or a synthetic oil having a sulfur content not exceeding 300 ppm. Also, in a preferred embodiment, the present invention provides a lubricating oil composition with even less sediment generation and superior energy-saving properties, while adding, as an additive, an aliphatic amine.

According to the present invention, it is possible to obtain a lubricating oil composition which inhibits corrosion and sediment generation. In addition, it is possible to effectively reduce friction losses caused by various types of industrial appliances and to ensure energy savings. In addition, if used as a hydraulic oil, it is possible, by reducing the coefficient of friction, to control the hydraulic apparatus with satisfactory accuracy and without the occurrence of phenomena such as chatter, vibration, winches or other abnormal noises in the hydraulic cylinders.

For the base oils of this lubricating oil composition, mineral oils and synthetic oils known as highly refined base oils may be used. In particular, base oils belonging to Group I, Group II, Group III, Group IV and so on may be used alone as API (American Petroleum Institute) base oil categories. For the base oils used herein, the elemental sulfur content should not be more than 300 ppm, preferably not more than 200 ppm, more preferably not more than 100 ppm, and most preferably not more than 50 ppm. . In addition, it is preferred that the density be from 0.8 to 0.9, preferably from 0.8 to 0.865, and more preferably from 0.81 to 0.83. The aromatic content is preferably less than 3%, more preferably less than 2% and even more preferably less than 0.1.

Group II base oils include, for example, paraffinic mineral oils, obtained by appropriate use of a suitable combination of refining processes, such as hydrorefining and wax removal with respect to lubricating oil fractions obtained by atmospheric distillation of crude oil. . Group II base oils, refined by hydrorefining methods such as the Gulf Company method, have a total sulfur content of less than 10 ppm and an aromatic content of not more than 5% and are therefore suitable. for the present invention. The viscosity of these base oils is not particularly limited, but the viscosity index may be from 80 to 120 and preferably from 100 to 120. The kinetic viscosity at 40 ° C (ASTM D445) is preferably from 2 to 680 mm2 / even more preferably from 8 to 220 mm / s. The total sulfur content may also be less than 300 ppm, preferably less than 200 ppm and even more preferably less than 10 ppm. The total nitrogen content is less than 10 ppm and preferably less than 1 ppm. In addition, oils with an aniline point of 80 to 150 ° C and preferably 100 to 135 ° C may be used.

Among Group III base oils and Group II + base oils, paraffinic mineral oils, manufactured with a high degree of hydrophore, with respect to lubricating oil fractions obtained by atmospheric distillation of crude oil, process-refined base oils Isodewax, which removes wax and replaces the wax produced by the wax removal process with isoparaffins and refined base oils by the Mobil wax isomerization process are suitable, for example. The viscosity of these base oils is not particularly limited, but the viscosity index may be from 95 to 145 and preferably from 100 to 140. The kinetic viscosity at 40 ° C may preferably be from 2 to 680 mm2 / s, even. more preferably from 8 to 220 mm 2 / s. Also the total sulfur content will be from 0 to 100 ppm and preferably less than 10 ppm. The total nitrogen content should be less than 10 ppm and preferably less than 1 ppm. In addition, oils with an aniline point of 80 to 150 ° C and preferably 110 to 135 ° C may be used.

GTLs (gas-to-liquid base oils) synthesized by the Fischer-Tropsch method of converting natural gas into liquid fuel have a very low sulfur content and aromatic content compared to refined mineral oil base oils. crude oil, and have a very high paraffin constituent ratio, and thus have excellent oxidative stability and, because they also have extremely small evaporative losses, are suitable as base oils for the present invention. The viscosity characteristics of GTL base oils are not particularly limited, but normally the viscosity index should be from 130 to 180 and preferably from 140 to 175. The kinetic viscosity at 40 ° C can also be from 2 to 680 mm. even more preferably from 5 to 120 mm 2 / s. Typically, the total sulfur content may also be less than 10 ppm and the total nitrogen content may be less than 1 ppm. A commercial example of such base oil derived from GTL is Shell XHVI (registered trademark).

As examples of synthetic oils, mention may be made of polyolefins, alkylbenzenes, alkylnaphthalenes, esters, polyoxyalkylene glycols, polyphenyl ethers, dialkyl diphenyl ethers, fluorine containing compounds (perfluoropolyethers, fluorinated polyolefins) and silicone oils.

The aforementioned polyolefins include polymers of various olefins or their hydrides. Any olefin may be used and, as examples, mention may be made of ethylene, propylene, butene and α-olefins having five or more carbons. In the manufacture of polyolefins, one species of the above mentioned olefins may be used alone or two or more species may be used in combination. Particularly suitable are polyolefins called poly-olefins (PAO). These are Group IV base oils. The viscosity of these synthetic oils is not especially limited, but the kinetic viscosity at 40 ° C may preferably be from 2 to 680 mm / s and even more preferably from 8 to 220 mm / s. The amount of the above base oil of the lubricating oil composition of the present invention is not particularly limited, however, based on the total amount of the lubricating oil composition, it is usually no less than 60% by weight, preferably not less than that is 80 wt.%, more preferably not less than 90 wt.% and even more preferably not less than 95 wt.%.

Aspartic acid derivatives are shown by general formula 1.

Chemical Structure 1 In the above-mentioned general formula 1 each of X1 and X2 are hydrogen atoms or the same or different alkyl groups or hydroxyalkyl groups having from 3 to 6 carbon atoms and preferably a 2-methylpropyl group and a group. tertiary butyl, respectively, are good. X 3 refers to alkyl groups consisting of 1 to 30 carbon atoms, or alkyl groups having ether bonds, or hydroxyalkyl groups. For example, octadecyl groups, alkoxypropyl groups and (C6 -C18) oxide and hydrocarbon (C1 -C6) alkyl groups are good and preferably cyclohexyloxypropyl groups, 3-octyloxypropyl groups, 3-isooctyloxypropyl groups, 3-decyloxypropyl groups, 3-isodecyloxypropyl groups and 3- (C 12 -C 16) alkoxypropyl groups. X4 refers to saturated or unsaturated carboxylic groups having from 1 to 30 carbon atoms, or alkyl groups having from 1 to 30 carbons, or alkenyl groups or hydroxyalkyl groups. For example, propionic acid groups and propionyl acid groups are good. The above aspartic acid derivative preferably has an acid number as determined by JIS K2501 of from 10 to 200 mgKOH / g and preferably from 50 to 150 mgKOH / g. The aspartic acid derivative is used in the lubricating agent composition in the order of 0.1 to 5 wt% and preferably in the order of 0.05 to 2 wt%. The epoxidized ester compound can be manufactured by epoxying esters of rapeseed oil, soybean oil, flaxseed oil, castor oil, coconut oil, palm oil, palm seed oil, sunflower oil, bran oil rice, safflower oil, beef fat, pork fat and so on. Mention may be made of rapeseed oil esters, epoxidized soybean oil esters, epoxidized linseed oil esters, epoxidized castor oil esters, epoxidized safflower oil esters and also of those manufactured by epoxidizing oleic acid esters, such as methyl epoxystearate, butyl epoxystearate and octyl epoxystearate.

Also the alcoholic residues of the esters may be alkyl groups or alkyl groups having ether bonds, or hydroxyalkyl groups and preferably butyl groups, isobutyl groups or 2-ethylexyl groups.

As examples, mention may be made of epoxidized rapeseed fatty acid isobutyl ester, epoxidized rapeseed fatty acid 2-ethylexyl ester and epoxidized linseed oil fatty acid ester. The main constituents of common rapeseed fatty acids are 18-carbon fatty acids with 63% oleic acid, 20% linolic acid and 8% linolenic acid. The main constituents of rapeseed fatty acids are 18-carbon fatty acids with 21% oleic acid, 13% linolic acid and 57% linolenic acid.

These epoxidized ester compounds are known as plasticizers and stabilizers for rubbers and plastics. The amount of epoxidized ester compound mixed in the lubricating oil composition is preferably from 0.01 to 5 weight percent, preferably from 0.01 to 2 weight percent and even more preferably from 0.01 to 5 weight percent. 1 percent by weight.

An aliphatic amine compound may further be incorporated into this lubricating oil composition and, as examples of such aliphatic amine compounds, mention may be made of the primary amines shown in General Formula (2) and General Formula (3) and the secondary amines shown. in the General Formula (4). Formula 2 H2N - X5 (2) In the above formula (2), X5 refers to saturated or unsaturated alkyl groups having from 1 to 30 carbon atoms. For example, mention may be made of laurylamine, coconut amine, n-tridecylamine, myristylamine, n-pentadecylamine, n-palmitylamine, n-heptadecylamine, n-stearylamine, isostearylamine, n-nonadecylamine, n-eicosylamine, n-henicosylamine, n-docosylamine, n-tricosylamine, n-pentacosylamine, oleylamine, beef tallow amine, hydrogenated beef tallow amine and soybean amine. Preferably the number of carbons of X5 is from 8 to 24 and more preferably from 12 to 18. Also X5 may be a tertiary alkyl group of a straight chain aliphatic or a branched chain aliphatic. Formula 3 H2N - X6 - NH2 (3) In the above formula (3), X6 refers to saturated or unsaturated alkylene groups having from 1 to 30 carbon atoms. For example, mention may be made of ethylenediamines such as laurylethylenediamine, coconut ethylenediamine, n-tridecylethylenediamine, myristylethylenediamine, n-pentadecylethylenediamine, n-palmitylethylenediamine, n-heptadecylethylenediamine, n-steaethylenediamine, -hekenylethylenediamine, n-docosylethylenediamine, n-tricosylethylenediamine, n-pentacosylethylenediamine, oleylethylenediamine, beef tallow ethylenediamine, and soybean ethylenediamine ethylenediamine. Preferably the number of carbons of Xe is from 8 to 24 and more preferably from 12 to 18. Formula 4 X7 - NH - X8 (4) In the above formula (4), X7 and X8 refer to saturated or unsaturated alkyl groups. having from 1 to 30 carbon atoms. For example, mention may be made of dilaurylamine, coconut diamine, di-n-tridecylamine, di-n-myristylamine, di-n-pentadecylamine, di-n-palmitylamine, di-n-heptadecylamine, di-n- stearylamine, diisoestearylamine, di-n-nonadecylamine, di-n-eicosylamine, di-n-henicosylamine, di-n-docosylamine, di-n-tricosylamine, di-n-pentacosylamine, dioleylamine, beef tallow diamine, dihydrogenated beef tallow amine and soybean diamine. Preferably the number of carbons of X7 and X8 is from 8 to 24 and more preferably from 12 to 18. X7 and X8 may be the same or different.

At least one species of these aliphatic amines, selected from the above groups, may be used in the lubricating oil composition in the order of approximately 0.005 to 5% by weight and preferably in the order of approximately 0.01 to 1% by weight.

In addition to the aforementioned constituents, it is possible to make appropriate use of various additives as needed to further improve performance. Examples of these may include antioxidants, metal deactivators, extreme pressure agents, oil improvers, defoaming agents, viscosity index enhancers, pour point depressants, detergent dispersants, anti-corrosion agents, demulsifiers and other agents. lubricants known in the art.

The antioxidants used in the present invention are preferably those used in the practice of lubricating oils and mention may be made of phenol based antioxidants, amine based antioxidants and sulfur based antioxidants. These antioxidants may be used alone or in combinations within the range of 0.01 to 5 parts by weight relative to 100 parts by weight of the base oil.

As examples of the above-mentioned amine-based antioxidants, mention may be made of dialkyl diphenylamines such as p, p'-dioctyl diphenylamine (Nonflex OD-3 manufactured by Seiko Kagaku Ltd.), p, p'-di-a -methylbenzyl diphenylamine and Np-butylphenyl-N-p'-octylphenylamine, monoalkylphenylamines such as mono-t-butyldiphenylamine and monooctyldiphenylamine, bis (dialkylphenyl) amines such as di (2,4-diethylphenyl) amine and di (2-ethylamino). 4-nonylphenyl) amine, alkylphenyl-1-naphthylamines such as octylphenyl-1-naphthylamine and Nt-dodecylphenyl-1-naphthylamine, aryl-naphthylamines such as 1-naphthylamine, phenyl-1-naphthylamine, phenyl-2-naphthylamine, N- hexylphenyl-2-naphthylamine and N-octylphenyl-2-naphthylamine, phenylenediamines such as N, N-diisopropyl-p-phenylenediamine and Δ, Ν'-diphenyl-p-phenenediamine, and phenothiazines such as phenothiazine (manufactured by Hodogaya Chemical Co. Ltd .) and 3,7-dioctylphenothiazine.

As examples of sulfur based antioxidants, mention may be made of dialkyl sulphides such as didodecyl sulphide and dioctadecyl sulphide, thiodipropionic acid esters such as didodecyl thiodipropionate, dioctadecyl thiodipropionate, dimyristyl thiodipropionate and dodecyl dipropionate tibiimidazole and diodecyl dipropidate.

Phenol-based antioxidants include 2-t-butylphenol, 2-t-butyl-4-methylphenol, 2-t-butyl-5-methylphenol, 2,4-di-t-butylphenol, 2,4-dimethyl-6- t-butylphenol, 2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,5-di-t-butylhydroquinone (Antage DBH, manufactured by Kawaguchi Kagaku Co. Ltd.), 2,6 -di-t-butylphenol, 2,6-di-t-butyl-4-alkylphenols such as 2,6-di-t-butyl-4-methylphenol and 2,6-di-t-butyl-4-ethylphenol, and 2,6-di-t-butyl-4-alkoxyphenols such as 2,6-di-t-butyl-4-methoxyphenol and 2,6-di-t-butyl-4-ethoxyphenol.

They also include 3,5-di-t-butyl-4-hydroxybenzylmercaptooctyl acetate, alkyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionates such as n-octadecyl-3- (3). , 5-di-t-butyl-4-hydroxyphenyl) propionate (Yoshinox SS, manufactured by Yoshitomi Pharmaceutical Industries Co. Ltd.), n-dodecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, n-dodecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2'-ethylexyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate and acid benzenopropanoic 3,5-bis (1,1-dimethylethyl) -4-hydroxy-C 7 -C 9 branched alkyl esters (Irganox L35, manufactured by Ciba Specialty Chemicals Co. Ltd), 2,6-di-t-butyl α-dimethylamino-p-cresol, and 2,2-methylenebis (4-alkyl-6-t-butylphenols) such as 2,2'-methylenobis (4-methyl-6-t-butylphenol) (Antage W-400, manufactured by Kawaguchi Kagaku Co. Ltd.) and 2,2'-methylenebis (4-ethyl-6-t-butylphenol) (Antage W-500, manufactured by Kawaguchi Kagaku Co. Ltd.).

They further include bisphenols such as 4,4'-butylidenobis (3-methyl-6-t-butylphenol) (Antage W-300, manufactured by Kawaguchi Kagaku Co. Ltd.), 4,4'-methylenobis (2,6- di-t-butylphenol) (Ionox 220AH, manufactured by Shell Japan Co. Ltd.), 4,4'-bis (2,2-di-t-butylphenol), 2,2- (di-p-hydroxyphenyl) propane (Bisphenol A, manufactured by Shell Japan Co. Ltd.), 2,2-bis (3,5-di-t-butyl-4-hydroxyphenyl) propane, 4,4-cyclohexylidenebis (2,6-t-butylphenol) , hexamethylene glycolbis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (Irganox L09, manufactured by Ciba Specialty Chemicals Co. Ltd), triethylene glycolbis [3- (3-t-butyl-4) -hydroxy-5-methylphenyl) propionate] (Tominox 917, manufactured by Yoshitomi Pharmaceutical Industries Co. Ltd.), 2,2'-thio [diethyl-3- (3,5-di-t-butyl-4-hydroxyphenyl ) propionate] (Irganox L15, manufactured by Ciba Specialty Chemicals Co. Ltd), 3,9-bis {1,1-dimethyl-2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxyoxy} 2,4,8,10-tetraoxaspiro [5,5] undecane (Sumilizer GA80, manufactured by Sumitomo Chemicals Co. Ltd.), 4,4'-thiobis (3-methyl-6-t-butylphenol) (Antage RC, manufactured by Kawaguchi Kagaku Co. Ltd.) and 2,2'-thiobis (4, β-di-t-butyl resorcinol).

Mention may also be made of tetracis [methylene-3-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (Irganox L01, manufactured by Ciba Specialty Chemicals Co. Ltd), 1,1,3 -tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane (Yoshinox 930, manufactured by Yoshitomi Pharmaceutical Industries Co. Ltd.), 1,2,5-trimethyl-2,4,6-tris (3 , 5-di-t-Butyl-4-hydroxybenzyl) benzene (Ionox 330, manufactured by Shell Japan Co. Ltd.), bis- [3,3'-bis- (4'-hydroxy-3'-t butylphenyl) butyric] glycol ester, polyphenols such as 2- (3 ', 5'-di-t-butyl-4-hydroxyphenyl) methyl-4- (2 ”, 4" -di-t-butyl-3 "-hydroxyphenyl ) methyl-6-t-butylphenol and 2,6-bis (2'-hydroxy-3,3-t-butyl-5'-methylbenzyl) -4-methylphenol, and phenol-aldehyde condensates, such as pt- butylphenol and formaldehyde and pt-butylphenol and acetaldehyde condensates.

As examples of phosphorus-based antioxidants, mention may be made of triaryl phosphites, such as triamyl phosphites, mention may be made of triaryl phosphites such as triphenyl phosphite and tricresyl phosphite, trialkyl phosphites such as trioctadecyl phosphite and tridecyl. phosphite, and tridodecyl trithiophosphite.

Metal deactivators, which may be combined with the lubricating oil composition of the present invention, include benzotriazole, 4-alkyl benzotriazole benzotriazole derivatives such as 4-methyl benzotriazole and 4-ethyl benzotriazole, 5-alkyl benzotriazole such as 5-methyl-benzotriazole and 5-ethyl-benzotriazole, 1-alkyl-benzotriazoles such as 1-dioctylaminomethyl-2,3-benzotriazole and 1-alkyl-tolutriazoles such as 1-dioctylaminomethyl-2,3-tolutriazole, benzimidazole, and 2- (alkylthio) benzimidazole benzimidazole derivatives such as 2- (octyldithio) benzimidazole, 2- (decylditio) benzimidazole and 2- (dodecylditio) benzimidazole and 2- (alkylditio) toluimidazoles such as 2- ( octyldithio) toluimidazole, 2- (decylditio) toluimidazole and 2- (dodecylditio) toluimidazole.

They also include indazole, indazole derivatives of toluindazole derivatives such as 4-alkyl indazoles and 5-alkyl indazoles, benzothiazole, and benzothiazole derivatives derived from 2-mercaptobenzothiazole (Thiolite B-3100, manufactured by Chiyoda Kagaku Co. Ltd.), 2- (alkyl dithio) benzothiazoles such as (hexyl dithio) benzothiazole and 2-octyldithio) benzothiazole, 2- (alkyl dithio) tolutiazoles such as 2- (hexyl dithio) tolutiazole and 2- (octyldithio) tolutiazole, 2- (N, N-dialkyl dithiocarbamyl) benzothiazoles such as 2- (N, N-diethyl dithiocarbamyl) benzothiazole, 2- (N, N-dibutyldithiocarbamyl) benzothiazole and 2- (N, N-diexydithiocarbamyl) benzothiazole, 2- (N, N-N-dialkyl dithiocarbamyl) ) -tolutiazoles such as 2- (N, N-diethyl dithiocarbamyl) tolutiazole, 2- (N, N-dibutyldithiocarbamyl) tolutiazole and 2- (N, N-diexydithiocarbamyl) tolutiazole.

They further include benzoxazole derivatives of 2- (alkyl dithio) benzoxazoles such as 2- (octyldithio) benzoxazole, 2- (decyldithium) benzoxazole and 2- (dodecyl dithio) benzoxazole, and 2- (alkyldithio) toluoxazoles such as 2- (octyldithium) ) toluoxazole, 2- (decylditio) toluoxazole and 2- (dodecylditio) toluoxazole, thiadiazole derivatives of 2,5-bis (alkyldithio) -1,3-4-thiadiazoles such as 2,5-bis (heptyldithio) -1, 3-4-thiadiazole, 2,5-bis (nonylditio) -1,3-4-thiadiazole, 2,5-bis (dodecylditio) -1,3-4-thiadiazole and 2,5-bis (octadecylditio) -1 , 3-4-thiadiazole, 2,5-bis (N, N-dialkyl dithiocarbamyl) -1,3-4-thiadiazoles such as 2,5-bis (N, N-diethyl dithiocarbamyl) -1,3-4-thiadiazole, 2,5-bis (N, N-dibutyldithiocarbamyl) -1,3-4-thiadiazole and 2,5-bis (N, N-dioctyldithiocarbamyl) -1,3-4-thiadiazole, 2-N, N-dialkyl dithiocarbamyl- 5-mercapto-1,4,4-thiadiazoles such as 2-N, N-dibutyldithiocarbamyl-5-mercapto-1,3,4-thiadiazole and 2-N, N-dioctyldithiocarbamyl-5-mercapto-1,3,4 thiadiazole, and triazole derivatives of 1-alkyl-2,4-triazoles such as 1-dioctylamino methyl-2,4-triazole. These metal deactivators may be used alone or in combinations within the beech of from 0.01 to 0.5 parts by weight relative to 100 parts by weight of the base oil. In order to impart wear resistance and extreme pressure properties to the lubricating oil composition of the present invention, it is also possible to add phosphorus compounds. As examples of compounds suitable for the present invention, mention may be made of phosphate esters, acid phosphate esters, amine salts of acid phosphate esters, chlorinated phosphate esters, phosphite esters, phosphorothionates, zinc dithiophosphates, esters or their derivatives of dithiophosphates and alkanol or polyether alcohols, phosphorus-containing carboxylic acids and organic phosphorus-containing carboxylate esters. These phosphorus compounds may be used alone or in combinations within the range of 0.01 to 2 parts by weight relative to 100 parts by weight of the base oil.

As examples of the above-mentioned phosphate esters, mention may be made of tributyl phosphate, tripentyl phosphate, triexyl phosphate, trieptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, tridodecyl phosphate, tritridadecyl phosphate, tritetradecyl phosphate, triexadecyl phosphate, trieptadecyl phosphate, triociadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tris (isopropylphenyl) phosphate, triallyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate and xylenyldiphenyl phosphate.

As specific examples of acid phosphate esters, mention may be made of monobutyl acid phosphate, monopentyl acid phosphate, monoexyl acid phosphate, monoeptyl acid phosphate, monoctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate, phosphate monoundecyl acid, monododecyl acid phosphate, monotridecyl acid phosphate, monotetradecyl acid phosphate, monopentadecyl acid phosphate, monoexadecyl acid phosphate, moneptadecyl acid phosphate, monoleyl acid phosphate, dibutyl acid phosphate, dipentyl acid, diexyl acid phosphate, dieptyl acid phosphate, dioctyl acid phosphate, dinonyl acid phosphate, didecyl acid phosphate, diundecyl acid phosphate, didodecyl acid phosphate, ditridecyl acid phosphate, phosphate dipentadecyl acid, diexadecyl acid phosphate, diepta acid phosphate decyl, dioctadecyl acid phosphate and dioleyl acid phosphate.

As examples of the above-mentioned amine salts of acid phosphate esters, mention may be made of the amine salts of the above mentioned phosphate esters such as methylamines, ethylamines, propylamines, butylamines, pentylamines, hexylamines, octylamines, dimethylamines, diethylamines. , dipropylamines, dibutylamines, dipentylamines, diexylamines, dieptylamines, dioctylamines, trimethylamines, triethylamines, tripropylamines, tributylamines, triexylamines, trieptylamines and trioctylamines.

As examples of the above mentioned phosphite esters, mention may be made of dibutyl phosphite, dipentyl phosphite, diexyl phosphite, dieptil phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, didodecyl phosphite, dioleyl phosphite, diphenyl phosphite, dicresyl phosphite, tributyl phosphite, tripentyl phosphite, triexyl phosphite, trieptil phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, triundecyl phosphite, tridodecyl phosphite, trioleyl phosphite, triphenyl phosphite and tricresyl phosphite.

As examples of the aforementioned phosphorothioates, mention may be made specifically of tributyl phosphorothioate, tripentyl phosphorothioate, triexyl phosphorothione, triexyl phosphorothione, trioctyl phosphorothione, trinonyl phosphorothioneate, tridecyl phosphorothioate, triundecyl phosphorothioneate, tridodecyl phosphorothiohydrate, triexyl phosphorothioneate phosphorothionate, trieptadecyl phosphorothionate, trioctadecyl phosphorothionate, trioleyl phosphorothionate, triphenyl phosphorothionate, tricresyl phosphorothionate, trixylenyl phosphorothionate, cresylphenyl phosphorothionate, xylenyldiphenyl phosphorylphosphoryl (phosphorylphenyl) phosphorylate tris (t-butylphenyl) phosphorothionate. These can also be used in their mixtures.

As examples of the above mentioned zinc dithiophosphates, mention may be made in general of zinc dialkyl dithiophosphates, zinc diaryl dithiophosphates and zinc arylalkyl dithiophosphates. For example, with respect to alkyl groups of zinc dialkyl dithiophosphates, zinc dialkyl dithiophosphates having primary or secondary alkyl groups of 3 to 22 carbons or alkylaryl groups substituted by alkyl groups of 3 to 18 carbons may be used. As specific examples of zinc dialkyl dithiophosphates, mention may be made of zinc dipropyl dithiophosphate, zinc dibutyl dithiophosphate, zinc dipentyl dithiophosphate, zinc dihydrophosphate diisopentyl dithiophosphate, zinc dithiophosphate diethylphosphate zinc dithiophosphate, didecyl zinc dithiophosphate, zinc didodecyl dithiophosphate, zinc dipropylphenyl dithiophosphate, zinc dipentylphenyl dithiophosphate, dipropylmethylphenyl dithiophosphate zinc dithiophosphate zinc dithiophosphate

Fatty acid esters of polyhydric alcohols may be mixed with the lubricating oil composition of the present invention with a view to improving oiliness. For example, partial or complete esters of saturated or unsaturated fatty acids of 1 to 24 carbons and polyhydric alcohols such as glycerol, sorbitol, alkylene glycols, neopentyl glycol, trimethylolpropane, pentaerythritol and xylitol may be used.

Examples of glycerol esters are glycerol monolaurylate, glycerol monostearate, glycerol monopalmitate, glycerol monooleate, glycerol dilaurylate, glycerol distearate, glycerol dipalmitate and glycerol dioleate. As examples of sorbitol esters mention may be made of sorbitol monolaurylate, sorbitol monopalmitate, sorbitol monostearate, sorbitol monooleate, sorbitol dilaurylate, sorbitol dipalmitate, sorbitol distearate, sorbitol dioleate, sorbitol triestearate sorbitol treauryl treaurylate sorbitol .

Examples of alkylene glycol esters are ethylene glycol monolaurylate, ethylene glycol monostearate, ethylene glycol monooleate, ethylene glycol dilaurylate, ethylene glycol dioleate, propylene glycol monolaurylate, propylene glycol monostearate, propylene glycol monoleate propylene glycol propylate diolate, propylene glycol dioleate. As examples of neopentyl glycol esters, mention may be made of neopentyl glycol monolaurylate, neopentyl glycol monostearate, neopentyl glycol monooleate, neopentyl glycol dilaurylate, neopentyl glycol distearate and neopentyl glycol dioleate.

Examples of trimethylolpropane esters include trimethylolpropane monolaurylate, trimethylolpropane monostearate, trimethylolpropane monooleate, trimethylolpropane dilaurylate, trimethylolpropane distearate, trimethylolpropane dioleate and pentaerythritol monolaurylate. Examples of pentaerythritol esters include pentaerythritol monostearate; pentaerythritol monooleate, pentaerythritol dilaurylate, pentaerythritol distearate, pentaerythritol dioleate and dipentaerythritol monooleate. For these fatty acid esters of polyhydric alcohols, it is preferable to use partial esters of polyhydric alcohols and unsaturated fatty acids.

Pour point depressants and viscosity index enhancers may also be added to the lubricating oil composition of the present invention in order to improve the low temperature flow characteristics and viscosity characteristics. As examples of viscosity index enhancers, mention may be made of non-dispersing viscosity index enhancers, as exemplified by polymethacrylates and olefin polymers such as ethylene propylene copolymers, styrene diene copolymers, polyisobutylene and polystyrene, or dispersant-like viscosity index enhancers, which are copolymerized with nitrogen-containing monomers. The amount thereof added may be within the range of 0.5 to 20 parts by weight relative to 100 parts by weight of the base oil.

As examples of the pour point depressants, mention may be made of polymethacrylate based polymers. Its amount may be within the range of 0.01 to 5 parts by weight relative to 100 parts by weight of the base oil.

Defoaming agents may also be added to impart foam resistance to the lubricating oil composition of the present invention. Examples of suitable defoaming agents may include dimethylpolysiloxane, organosilicates such as diethylsylate and fluorosilicones and non-silicone defoaming agents such as polyalkylacrylates. Its added amount may be within the range of 0.0001 to 0.1 part by weight relative to 100 parts by weight of the base oil.

For demulsifiers suitable for the present invention mention may be made of those in the known art commonly used as lubricating oil additives. Its added amount may be within the range of 0.0005 to 0.5 part by weight relative to 100 parts by weight of the base oil.

Examples The invention is explained in more detail below by way of Examples and Comparative Examples, but the invention is not limited to those Examples.

The following materials were used in the preparation of Examples and Comparative Examples. 1. Base Oils (1-1) Base Oils 1: A paraffinic mineral oil, obtained by a suitable combination of refining procedures, such as hydrocracking and wax removal of a lubricating oil fraction obtained by atmospheric distillation of crude oil. . Categorized as Group II (Gp II) according to API (American Petroleum Institute) base oil categories. (Features: kinetic viscosity at 100 ° C: 5.35 mm / s; kinetic viscosity at 40 ° C: 3.4 mm / s; viscosity index: 103; density at 15 ° C: 0.864; sulfur content (when converted to elemental sulfur): less than 10 ppm; nitrogen content (when converted to elemental nitrogen): less than 1 ppm; aniline point: 110 ° C; paraffin content in ring analysis as determined by ASTM D3238: 62%, same for naphthalene content: 38%, same for aromatic content: less than 1%, initial boiling point based on gas chromatography distillation as determined by ASTM D5480: 312 ° C). (1-2) Base Oil 2: A paraffinic mineral oil obtained by a suitable combination of refining procedures such as hydrocracking and wax removal of a lubricating oil fraction obtained by atmospheric distillation of crude oil. Categorized as Group III (Gp III) according to API (American Petroleum Institute) base oil categories. (Characteristics: Kinetic viscosity at 100 ° C: 6.57 mm / s; • Kinetic viscosity at 40 ° C: 37.5 mm / s; Viscosity index: 130; Density at 15 ° C: 0.823; sulfur (when converted to elemental sulfur): less than 10 ppm nitrogen content (when converted to elemental nitrogen): less than 1 ppm aniline point: 130 ° C paraffin content in ring analysis as determined by ASTM D3238: 78%; same for naphthen content: 22%; same for aromatic content: less than 1%; polycyclic aromatic content according to IP 346: 0.2%). (1-3) Base Oil 3: A GTL oil synthesized by the Fischer-Tropsch method and categorized as group III according to API (American Petroleum Institute) oil categories. (Characteristics: kinetic viscosity at 100 ° C; 5.10 mm / s; kinetic viscosity at 40 ° C; 23.5 mm Is; viscosity index: 153; density at 15 ° C: 0.821; sulfur content (when converted elemental sulfur): less than 10 ppm; nitrogen content (when converted to elemental nitrogen): less than 1 ppm; aromatic content in ring analysis as determined by ASTM D3238: less than 1%). (1-4) Base Oil 4: A synthetic poly-a-olefin oil, commonly known as PAO6, and categorized as Group IV according to API (American Petroleum Institute) base oil categories. Λ (Features: kinetic viscosity at 100 ° C: 5.89 mm / s; kinetic viscosity at 40 ° C: 31.2 mm / s; viscosity index: 135; density at 15 ° C: 0.827; sulfur content (when converted to elemental sulfur): less than 10 ppm nitrogen content (when converted to elemental nitrogen): less than 1 ppm aniline point: 128 ° C aromatic content in ring analysis as determined by ASTM D3238: less than 1% initial boiling point based on gas chromatography distillation as determined by ASTM D5480: 403 ° C. (1-5) Base Oil 5: A paraffinic mineral oil obtained by a suitable combination of Refining procedures, such as removal of wax from a fraction of lubricating oil obtained by atmospheric distillation of crude oil Categorized as Group I (Gp I) according to API (American Petroleum Institute) base oil categories. t 2 kinetic viscosity at 100 ° C: 4.60 mm / s; at 40 ° C: 24.6 mm Is; viscosity index: 101; density at 15 ° C: 0.866; sulfur content (when converted to elemental sulfur): 460 ppm; nitrogen content (when converted to elemental nitrogen): 20 ppm; aniline point: 110 ° C; paraffin content in ring analysis as determined by ASTM D3238: 66%; same for naphthene content; 31%; same for aromatic content: 3%; aniline point: 99 ° C; polycyclic aromatic content according to IP 346: 0.8%: initial boiling point based on gas chromatography distillation as determined by ASTM D5480: 331 ° C. 2. Additives (2-1) Additive Al: Aspartic acid derivative: K-CORR100, manufactured by King Co. Ltd., acid number according to JIS K2501 method: 100mgKOH / g (2-2) Additive A2: Aspartic Acid Derivative: MONACOR 39, manufactured by Unichema Co. Ltd., acid number according to JIS K2501 Method: 60 mgKOH / g (2-3) Additive Bl: Isobutyl Epoxidized Rapeseed Fatty Acid Ester (2- 4) Additive B2: Epoxidized rapeseed fatty acid ester 2-ethylexyl (2-5) Additive B3: Epoxidized linseed fatty acid ester (2-6) Additive B4: Epoxidized soybean oil (2-7) Additive Cl : Coconut amine (main constituent dodecylamine); primary alkyl primary amine compound, base number according to JIS method K2501: 390 mgKOH / g. (2-8) C2 Additive: Oleylamine; primary alkyl primary amine compound, base number according to JIS method K2501: 215 mgKOH / g. (2-9) Additive C3: Ox cam tallow amine (major constituents oleylamine, stearylamine, palmitylamine); primary alkyl primary amine compound, base number according to JIS method K2501: 215 mgKOH / g. (2-10) C4 Additive: Primary amine with C1-8 tertiary alkyl group; tertiary alkyl primary amine compound, base number according to JIS method K2501: 155 mgKOH / g. (2-11) Additive C5: Coconut diamine (main constituent of dodecyldiamine); primary alkyl primary diamine compound, base number according to JIS method K2501: 440 mgKOH / g. (2-12) C6 Additive: Coconut secondary amine (major didodecylamine constituent); secondary alkyl secondary amine compound, base number according to JIS method K2501: 160 mgKOH / g. (2-13) Other additives: The compounds shown below were mixed in: diphenylamine, phenylnaphthylamine, 3,5-bis91,1-dimethylethyl) -4-hydroxy-C 7 -C 9 branched alkyl ester of N, benzenopropanoic acid, N, N-bis (2-ethylhexyl) - (4 or 5) methyl-1H-benzotriazol-1-methylamine, triallyl phosphate, 3- (diisobutoxy-thiophosphorylsulfanyl) -2-methyl-propionic acid, pentaerythritol ester, polymethacrylate-like pour point, dimethylpolysiloxane-type defoaming agent and polyoxyethylene-polyoxypropylene glycol-type demulsifier.

Examples 1 to 21, Comparative Examples 1 to 7 Using the above materials, the lubricating oil compositions of Examples 1 to 21 and Comparative Examples 1 to 7 were prepared according to the compositions shown in Tables 1 to 7.

Tests Corrosion prevention tests and thermal stability tests were performed as below on the lubricating oil compositions of Examples 1 to 21 and Comparative Examples 1 to 7 to see how they performed. The pendulum tests for coefficient of friction were also performed.

Corrosion Prevention Test According to JIS K2510, 300 ml of the oil under test was drained into a container arranged at a constant temperature and stirred at a speed of 1000 revolutions per minute. When the temperature reached 60 ° C, an iron test piece was inserted into the test oil and 300 ml of artificial seawater was added. The temperature was maintained at 60 ° C while stirring continuously for 24 hours. The test piece was then removed and assessed by eye for the presence of any rust. If no hardware occurred, the oil was thought to have passed.

Thermal Stability Test According to the Cincinnati Milacron Inc. Thermal Stability Test Procedure 'A', 200 ml of the oil under test was drained into a container arranged in a constant temperature bath and left there for 168 hours, at 125 ° C in the associated presence of a copper catalyst and an iron catalyst. Then, after cooling to room temperature, the pellet was collected by a 5-micron filter and the amount of pellet generated was weighed. The table numbers are the amount of sediment per 200 ml of test oil (mg / 200 ml). Test evaluation was made according to the following criteria: Amount of sediment generated less than 2.0 mg 0 (Excellent) Amount of sediment generated 2.0 less than 10.0 mg O (Good) Amount of sediment generated 10.0 mg or more X (Failed) Pendulum test, coefficient of friction The coefficient of friction at 25 ° C was measured using a Masuda pendulum oil tester manufactured by Shinko Machine Manufacturing Co. Ltd .. In this test the oil being tested is supplied to the friction part of the pendulum fulcrum, the pendulum is moved and the coefficient of friction is obtained by reducing the oscillations. Test evaluation was made according to the following criteria: Friction coefficient 0.135 or less 0 (Excellent) Friction coefficient 0.136 less than 150 O (Good) Friction coefficient 0.150 or more X (Failed) Test Results The Test results are shown in Tables 1 to 7.

As evidenced by the results of Tables 1, 2 and 6, when the aspartic acid derivative of Comparative Example 2 (Additive Al) was added, it had adequate corrosion resistance, but the amount of sediment generated in the thermal stability test was great. However, it was possible to reduce the amount of sediment while having adequate corrosion resistance using also an epoxidized ester compound (Additive BI or B2) as in Examples 1 to 3 and Example 8. Also, if the amount of epoxidized ester ( Incorporated additive B1) was increased, the amount of sediment decreased and the sediment inhibiting effect was more marked, as shown by Examples 1 to 3. In addition, as shown by Examples 1 to 6, the amount of sediment was small in the compositions. lubricating oil using any of the highly refined base oils 1 to 4, and in particular, when using the highly refined base oils shown in Examples 4 to 6, the amount of sediment was extremely small (0: excellent) and the sediment inhibiting effect was even greater.

Similarly, as between Example 7 (Table 2) and Comparative Example (Table 6), superior corrosion resistance and superior sediment inhibiting effect were obtained using an aspartic acid derivative (Additive A2) together with a compound. of epoxidized ester (Additive Bl) in the base oil. Also, when looking at Example 9 (Table 2), excellent corrosion resistance and excellent sediment inhibiting effect of the aforementioned aspartic acid derivative and epoxidized ester compound were demonstrated even when using other additives therewith.

In Examples 10 to 13 (Table 3), sediment inhibition was even further enhanced by further using an aliphatic amine compound (Additive Cl) in the base oil, aspartic acid derivative and epoxidized ester compound and, Since the coefficient of friction was considerably lower than in Comparative Examples 1 to 6 (Table 6), excellent low friction characteristics were demonstrated. In particular, when using Base Oil 3 (Example 12) and Base Oil 4 (Example 13), it was possible to take the considerably lower coefficient of friction by combining these additives (0: excellent) and it was therefore possible to grant Excellent energy-saving characteristics of the lubricating oil composition.

Also in the case of both aspartic acid derivative (Additive A2) used in Example 14 (Table 4) and epoxidized ester compound (Additive B2 or B3) used in Examples 15 to 16 (Table 4) excellent corrosion resistance, excellent inhibition mud and excellent low friction characteristics were similarly obtained.

In the case of Examples 17 to 21 (Table 5), with various aliphatic amine compounds (Additives C2 to 6), excellent corrosion resistance, excellent sediment inhibition and excellent low friction characteristics have been demonstrated by combining an acid derivative. aspartic acid and epoxide ester compound. In particular, a considerable sediment inhibiting effect was obtained for Embodiment Example 19 using an aliphatic amine compound (Additive C4). Also in the case of Examples of Embodiment 17, 18 and 20 employing aliphatic amine compounds (Additives C2, C3, C5), it was possible to reduce the coefficient of friction considerably (0: excellent) and it was therefore possible to grant excellent characteristics of energy-saving lubricating oil compositions.

It was evident, as shown by Comparative Example 6, that in the case of Base Oil 5, which had a high sulfur content, sediment inhibition was poor, even when also using an aspartic acid derivative and a sulfur compound. epoxidized ester. Also as shown by Comparative Example 7, sludge inhibition was poor also when there was an epoxy compound but no sterilization.

Claims (10)

Lubricating oil composition, characterized in that it comprises a base oil having a sulfur content of not more than 300 ppm, an aspartic acid derivative and an epoxidized ester compound, wherein the aspartic acid derivative has the formula general 1 where X | and X1 are each hydrogen atoms or the same or different alkyl groups or hydroxyalkyl groups having from 3 to 6 carbon atoms; X 3 is an alkyl group having 1 to 30 carbon atoms, possibly containing an ether bond and / or a hydroxyalkyl group; X 4 is a C 1 -C 30 saturated or unsaturated carboxylic group, alkyl group, an ethylhexyl group or hydroxyalkyl group; wherein the amount of the aspartic acid derivative and epoxide ester compound each is from 0.01 to 5% by weight, based on the total composition. Lubricating oil composition according to claim 1, characterized in that the acid number of the aspartic acid derivative is from 10 to 250 mgKOH / g. Lubricating oil composition according to claim 1 or 2, characterized in that the epoxidized ester compound is an epoxidized fatty acid ester derived from animal and animal fats and / or oils and fats. Lubricating oil composition according to any one of claims 1 to 3, characterized in that it further comprises an aliphatic amine. Lubricating oil composition according to claim 4, characterized in that the aliphatic component of the fatty acid amine has from 8 to 24 carbons. Lubricating oil composition according to any one of claims 1 to 5, characterized in that the base oil is synthetic oil. Lubricating oil composition according to claim 6, characterized in that the base oil is a poly-olefin. Lubricating oil composition according to claim 6, characterized in that the base oil is a base oil derived from GTL. Use of the lubricating oil composition as defined in any one of claims 1 to 8, characterized in that it is as a machine oil, hydraulic oil, turbine oil, compressor oil, gear oil, slip friction oil. ; bearing oil and calibration oil. Method for improving lubrication, characterized by the use of the lubricating oil composition as defined in any one of claims 1 to 8.