RU2560964C2 - Lubricating oil composition for diesel engines - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: claimed invention relates to lubricating oil composition for application in Diesel engines, which contains in base oil not more than 0.3 wt % of sulphate ash content from 0.01 to 0.2 wt % of nitrogen in succinamides, from 0.05 to 0.12 wt % of zinc in zinc dithiophosphates, from 0.02 to 0.3 wt % of nitrogen in amine-based antioxidants and from 0.01 to 0.08 wt % of boron, which in addition has the total value of parameter [(quantity of zinc in zinc dithiophosphates)×(quantity of nitrogen in succinimides)] and [(quantity of zinc in zinc dithiophosphates)×(quantity of nitrogen in amine-based antioxidants)], constituting not less than 0.015, and composition does not contain salicylate phenolate or sulphonate metal-containing detergents.

EFFECT: obtaining lubricating oil composition for application in Diesel engines, which does not contain metal-containing detergent, however, preserves excellent washing ability for engine (piston), with prevention of DPF clotting and reduction of valve mechanism wear.

4 cl, 2 tbl, 4 ex

Description

FIELD OF THE INVENTION

The present invention relates to a lubricating oil composition for diesel engines, and more particularly, to a diesel lubricating oil composition having excellent detergency, while having extremely low ash, despite the fact that it does not include metal detergents.

State of the art

A diesel particulate filter (hereinafter referred to as DPF), which is considered to be an efficient way to remove particulate matter (hereinafter referred to as PM) in the exhaust gases of diesel engines, may become clogged (clogged) due to the presence of metal-containing components in the used engine oil. For example, it is known that ash is accumulated in DPF, which is formed from engine oils for diesel engines, and that this leads to a decrease in PM cleaning efficiency and a decrease in the service life of DPF, therefore it is considered necessary to reduce the sulfate ash content in engine oil for diesel engines, in other words, to reduce the content ashes.

This means that engine oils, and specifically engine oils for diesel engines, change over time due to changes in the fuel. For example, emissions of particulate matter, carbon monoxide and NOx from air pollution caused by exhaust gases are currently a problem, and, in particular, the sulfur content in diesel oils has sharply decreased over the past ten years or more from no more than 500 ppm . up to no more than 10 ppm As a result of these countermeasures, a device for the post-treatment of exhaust gases, known as DPF, is introduced, which is introduced into diesel engines. But in order to prevent clogging of DPF, low-ash motor oils are required.

As for the sulfur content, taking into account that sulfuric acid is formed during combustion and the sulfuric acid formed negatively affects both the washing ability for the piston and wear, and due to the fact that phosphorus in motor oils is known to poison catalysts for of exhaust gas purification, it is clear that the trend favoring the use of motor oils with a low content of sulfate ash, phosphorus and sulfur, known as "low SAPS" (low ash / low phosphorus / low sulphur), is becoming increasingly stronger.

In this transition to low ash oils, which has a major influence on the required characteristics of the aforementioned diesel engine oils, it is necessary to reduce the amounts of admixing additives that contain metals, such as metal detergents that give the oil a washing ability, and zinc dialkylthiophosphates (ZnDTP), which provide anti-wear characteristics.

To prevent the aforementioned clogging of DPF, a low-ash engine oil composition that does not contain any metal-containing additives can be considered, but if the amount of the metal-containing component is simply reduced compared to the engine oil compositions known from the prior art, the result will be the suppression of important functions of the engine oil composition, namely washing engine abilities, anti-wear characteristics and oxidation resistance.

For example, the purpose of the invention described in Japanese Patent Application Laid-Open No. 2007-254559 (Patent Reference 1) is to provide engine oil composition for diesel engines with low ash content, but the sulfate ash content in it is nonetheless significant and amounts to 0.6% (wt. ), the composition further includes a metal-containing detergent, so that provided that small amounts of a metal-containing detergent are used, the situation is that it continues to the previous level, even if the target is a low-ash motor oil.

The aim of the invention described in Japanese Patent Application Laid-open No. 2006-176672 (Patent Reference 2) is also a lubricating oil for internal combustion engines with excellent oxidation stability due to the low ash component. The application made an attempt to provide increased viscosity and acid number in such low-ash oil, but the main attention was not specifically focused on the washing ability for the piston. In addition, the sulfate ash content in the examples is extremely high, ranging from 0.99 to 1.01% (wt.).

The present invention is intended to provide a lubricating oil composition for diesel engines, such that maintains an excellent detergency for the engine (piston), while preventing clogging of the DPF and reducing wear on valve mechanisms, even without the inclusion of metal-containing detergents.

The present invention, without the inclusion of a metal-containing detergent, retains excellent detergency for the engine piston, while clogging of DPF and wear on valve mechanisms is prevented, creating a balance between zinc dithiophosphates, succinimides and amine-based antioxidants added to the base oil.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a lubricating oil composition for use in diesel engines, which contains no more than 0.3% (wt.) Sulphated ash in the base oil, 0.01-0.2% (wt.) Of nitrogen in succinimides, 0 05-0.12% (wt.) Of zinc in zinc dithiophosphates, 0.02-0.3% (wt.) Of nitrogen in amine based antioxidants and 0.01-0.08% (wt.) Of boron, and which, in addition, has the total value of the parameter [(amount of zinc in zinc dithiophosphates) × (amount of nitrogen in succinimides)] and [(amount of zinc in zinc dithiophosphates) × (amount of nitrogen in anti-oxygen amine-based sidants)], comprising from 0.015 to 0.06, preferably 0.015-0.04 and more preferably 0.01-0.04, and which does not contain salicylate phenolate or sulfonate metal-containing detergents.

DETAILED DESCRIPTION OF THE INVENTION

This is a lubricating oil composition that does not include metal detergents, i.e. where the metal-containing component formed from metal-containing detergents is not more than 0.01% (wt.).

The above base oil is preferably a base oil or a mixture of base oils selected from group II, group III, group IV and group V, and where the content of sulfur component in the base oil is not more than 50 ppm

In addition, the specified lubricating oil composition for use in diesel engines is such that TGF according to the method of testing the washing ability of motor oils JASO M336: 1998 is not more than 30%, and the wear of the working protrusion of the cam, determined by the method of testing the wear of the valve mechanism JASO M354: 1999, is not more than 95 microns.

In accordance with the present invention, it is possible to obtain a lubricating oil composition for use in diesel engines that does not include metal detergents, has a low ash content, while at the same time maintaining excellent washing ability for the piston, while clogging of DPF is prevented and valve wear is reduced, thereby This way the environmental load is reduced.

For the base oil used in the diesel engine lubricating oil composition of the present invention, it is possible, in particular, to use appropriate mineral oils, synthetic oils and mixtures thereof, as are commonly used for lubricating oils. In particular, it can be used individually or in the form of oil mixtures, which belong to the categories of base oils of group II, group III, group IV and group V according to API classification (American Petroleum Institute).

The aforementioned group II base oils include, for example, paraffinic mineral oils obtained by appropriate combination of refining methods, such as hydrocracking and dewaxing with respect to fractions of lubricating oils obtained by distillation of crude oil at atmospheric pressure. In Group II base oils purified by hydrotreating methods, such as the Gulf method, the total sulfur content is less than 10 ppm and the aromatic content is not more than 5%, and therefore they can be used for the present invention.

The viscosity of these base oils is not specifically limited, but the viscosity index should be 80-120 and preferably 100-120. The kinematic viscosity at 40 ° C should preferably be 2-680 mm / s and more preferably 8-220 mm ² / s. Moreover, the total sulfur content is less than 300 ppm, preferably less than 100 ppm. and more 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 80-150 ° C, preferably 100-135 ° C, should be used.

Group 2 Plus base oils that have a viscosity index above 115 may be indicated as preferred Group 2 base oils.

Group III base oils include, for example, paraffinic mineral oils obtained by hydrotreating a high degree of fraction of lubricating oils obtained by distillation of crude oil at atmospheric pressure, base oils purified by isodeparaffinization, which are dewaxed and replaced with isoparaffin waxes obtained by dewaxing methods, and base oils purified Mobile method by isomerization of waxes. All of these oils are also suitable for use in the present invention.

The viscosity of these base oils is not specifically limited, but the viscosity index should be 120-160 and preferably 120-150. The kinematic viscosity at 40 ° C should preferably be 2-680 mm ² / s and more preferably 8-220 mm ² / s. In this case, the total sulfur content should be less than 300 ppm, preferably less than 100 ppm. and more 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 80-150 ° C, and preferably 100-135 ° C, should be used.

Group 3 Plus base oils that have a viscosity index above 130 may be indicated as preferred Group 3 base oils.

Examples of synthetic oils include polyolefins, alkylbenzenes, alkylnaphthalenes, esters, polyoxyalkylene glycols, polyphenyl ethers, dialkyl diphenyl ethers, fluorine-containing compounds (perfluoro polyethers, fluorinated polyolefins, etc.) and silicones.

The aforementioned polyolefins include polymers of various olefins or their hydrides. Any olefin may be used, and examples include ethylene, propylene, butene and α-olefins containing 5 or more carbon atoms. In the production of polyolefins, one type of the aforementioned olefins may be used alone or two or more kinds thereof may be used in combination. Particularly suitable are polyolefins called poly-α-olefins (PAO). They are group IV base oils.

The viscosity of these synthetic oils is not specifically limited, but the kinematic viscosity at 40 ° C should preferably be 2-680 mm ² / s and more preferably 8-220 mm ² / s.

GTLs (gas-to-liquid) products synthesized by the Fischer-Tropsch process by converting natural gas to liquid fuel have a very low sulfur content and aromatic content comparable to mineral oil-free crude oils and a very high ratio of paraffin components, therefore have excellent oxidation stability, and since they also have extremely low evaporation losses, they are useful as base oils for the present invention.

The viscosity characteristics of GTL base oils are not specifically limited, but typically a viscosity index should be 120-180, preferably 130-175, and more preferably 140-175. In this case, the kinematic viscosity at 40 ° C should be 2-680 mm ² / s and preferably 5-120 mm ² / s. Typically, the total sulfur content is also less than 10 ppm, and the total nitrogen content is less than 1 ppm. An example of such an industry-standard GTL base oil is Shell XHVI (registered trademark).

The base oils mentioned above can be used individually or as mixtures, and their sulfur content should be less than 50 ppm, preferably less than 10 ppm. and more preferably less than 1 ppm.

As examples of the aforementioned zinc dithiophosphates, mention may generally be made of zinc dialkyldithiophosphates, zinc diaryldithiophosphates and zinc arylalkyldithiophosphates. For example, zinc dialkyldithiophosphates may be used in which the alkyl groups of zinc dialkyldithiophosphates include primary or secondary alkyl groups containing from 3 to 22 carbon atoms, or alkylaryl groups substituted by alkyl groups containing 3-18 carbon atoms. For example, zinc dialkyldithiophosphates, where the alkyl groups of zinc dialkyldithiophosphates have primary or secondary alkyl groups containing from 3 to 12 carbon atoms, or zinc diaryldithiophosphates, in which aryl groups are phenyl or alkylaryl groups substituted by alkyl groups containing 1-18 carbon atoms .

Preferred are zinc dithiophosphates with secondary alkyl groups containing 3-12 carbon atoms, preferably 3-8 carbon atoms, and more preferably 3-6 atoms.

As specific examples of the zinc dialkyldithiophosphates may be mentioned zinc dipropilditiofosfat, dibutilditiofosfat zinc dipentilditiofosfat zinc digeksilditiofosfat zinc diizopentilditiofosfat zinc dietilgeksilditiofosfat zinc dioktilditiofosfat zinc dinonilditiofosfat zinc didetsilditiofosfat zinc didodetsilditiofosfat zinc dipropilfenilditiofosfat zinc dipentilfenilditiofosfat zinc dipropilmetilfenilditiofosfat zinc dinonilfenilditiofosfat zinc and zinc dodecylphenyl dithiophosphate.

These zinc dithiophosphates are added to the lubricating oil composition so that the amount of zinc is 0.05-0.12% (wt.), But preferably 0.06-0.12% (wt.). Zinc dithiophosphates, as described above, are effective antiwear additives, but they contain phosphorus (P). Phosphorus compounds are known to poison catalysts for exhaust gas purification, and if the phosphorus content in the composition increases, the likelihood of negatively affecting the exhaust gas purification catalyst increases. For this reason, if zinc dithiophosphate is introduced in such an amount that the amount of zinc exceeds 0.12% (wt.), There is a concomitant increase in the phosphorus content in the composition, which is undesirable. In addition, if the aforementioned upper limit is exceeded, the action of the anti-wear additive is suppressed, so that a result corresponding to costs is not achieved, which is not effective. On the other hand, if the amount of zinc is less than 0.05% (wt.), The result in the context of the action of antiwear additives may not achieve the goal.

In the lubricating oil composition of the present invention, alkenyl succinimide or alkyl succinimide and / or a boron modified derivative thereof are used for the aforementioned succinimide. It functions as an ashless dispersant.

As suitable examples of alkenyl or alkyl succinimide, mention may be made of alkenyl or alkyl succin monoimides represented by the general formula (1) and alkenyl or alkyl succin bis-imides represented by the general formula (2).

General formula 1:

General formula 2:

In the above general formulas (1) and (2), R ¹ , R ³ and R ⁴ each represents an alkenyl group or an alkyl group with a weight average molecular weight of from 500 to 3000, and R ³ and R ⁴ may be the same or different. R ² , R ⁵ and R ⁶ each represents an alkylene group containing from 2 to 5 carbon atoms, and R ⁵ and R ⁶ may be the same or different; t is an integer from 1 to 10, and n is 0 or an integer from 1 to 10.

The mass-average molecular weight of each R ¹ , R ³ and R ⁴ in the general formulas (1) and (2) is, as indicated above, from 500 to 3000, but preferably from 1000 to 3000. If the mass-average molecular weight is less than 500, the solubility in the base oil will decrease, and if it exceeds 3000, the washing ability decreases, so there is a risk that the set functions will not be achieved.

Moreover, the aforementioned t is an integer from 1 to 10, but preferably from 2 to 5, and more preferably from 3 to 4. If m exceeds 2, a good washing ability is achieved. If m is less than 5, the solubility in the base oil will be good.

In the general formula (2), n is 0 or an integer from 1 to 10, but preferably from 1 to 4, and more preferably from 2 to 3. If n exceeds 1, good detergency is achieved, and if n is less than 4, it will be good solubility in base oil.

Examples of alkenyl groups in general formulas (1) and (2) are polybutenyl groups, polyisobutenyl groups and ethylene-propylene copolymers. Alkyl groups include their hydrogenated forms. Typical examples of suitable alkenyl groups include polybutenyl groups, polyisobutenyl groups. These polybutenyl groups are obtained by polymerization of mixtures of 1-butene and isobutene or isobutene of high purity.

Moreover, the hydrogenated forms of polybutenyl groups or polyisobutenyl groups are typical examples of suitable alkyl groups.

The aforementioned alkenyl or alkyl succinimides can be obtained, as a rule, by reacting with a polyamine anhydrous alkenyl succinimide obtained by reacting a polyolefin with maleic anhydride or an anhydrous alkyl succinimide obtained by hydrogenation of alkenyl succinimide.

The aforementioned succin monoimides and β-bis-imides can be obtained by varying in the reaction the ratios of anhydrous alkenyl succinic acids or anhydrous alkyl succinic acids and polyamines.

For the olefin monomer that forms the above polyolefin, mixtures of one or two or more types of α-olefins containing from 2 to 8 carbon atoms can be used, and a mixture of isobutene and butene-1 can be used with satisfactory result.

Examples of the above polyamines include single diamines, such as ethylenediamine, propylene diamine, butylenediamine and pentylenediamine; and as examples of polyalkylene polyamines, mention may be made of diethylene triamine, triethylenetetramine, tetraethylene pentamine, pentaethylene hexamine, di (methylene) triamine, dibutylene triamine, tributylene tetramine and pentapentylene hexamine.

Moreover, for modified with boron derivatives of alkenyl or alkyl succinimides, it is possible to use succinimides obtained by conventional methods. For example, they can be obtained after the aforementioned polyolefins are converted to anhydrous alkenyl succinimides by reacting them with maleic acid and further imidating by reacting with an intermediate compound obtained by reacting the aforementioned polyamines with a boron compound such as boron oxide, boron halide, boric acid, boric anhydride acids, boric acid ester or ammonium salt of boric acid.

The lubricating oil composition of the present invention contains, based on the weight of the composition, from 0.01 to 0.2% (wt.), Based on the content of nitrogen, alkenyl or alkyl succin monoimide or bis-imide and / or a boron-modified derivative thereof as ashless dispersant, but preferably contains from 0.05 to 0.15% (wt.).

If the content of alkenyl or alkyl succin monoimide or bis-imide and / or a derivative modified with boron is less than 0.01% (wt.), The action as an ashless dispersant will not be shown to a satisfactory degree, and if it exceeds 0.2% (wt. ), you can see the negative effect on rubber parts, such as elastomers used in engines.

The content of the boron-modified derivative of alkenyl or alkyl succinic acid ionoimide in the specified ashless dispersant will be, calculated on boron, from 0.01 to 0.08 (wt.) And preferably from 0.04 to 0.07% (wt. )

Even if the content of alkenyl or alkyl succinic acid monoimide converted to boron and / or its derivative modified with boron in an ashless dispersant is less than 0.01% (wt.), The effect of antiwear high temperature detergent characteristics is insufficient, and if it exceeds 0.08% (wt. .), then the effective characteristics go to saturation (to the limit) and economic efficiency decreases.

In this case, boron is obtained from the forms of succinimides modified with boron, and for the amount of succinimide added in the above ranges it is often undesirable if the boron-containing component is added in excess, since an excess of the boron-containing component can cause DPF clogging due to an increase in the sulfate ash formed by the increased boron content in the recipe.

For amine-based antioxidants used in this invention, the antioxidants commonly used for lubricating oils are preferred for practical use, and they can be used individually or in numerous combinations in a lubricating oil composition in the range of 0.02 to 0.3% (wt. .) based on the nitrogen content

Amine-based antioxidants are prone to surface adsorption in their structure, and since zinc dithiophosphate, an anti-wear agent, decomposes and acidic intermediates are adsorbed on the surface, in which case it is undesirable to add an excess amount, therefore it is better to control the upper limit.

Examples of the above amine-based antioxidants include dialkyl diphenylamines such as n, n′-dioctyl diphenylamine (Nonflex OD-3 manufactured by Seiko Chemical Ltd), n, n′-di-α-methylbenzyl diphenylamine and Nn-butylphenyl-Nn ′ octylphenylamine; monoalkyl diphenylamines such as mono-tert-butyl diphenylamine and monooctyl diphenylamine; bis (dialkylphenyl) amines, such as di- (2,4-diethylphenyl) amine and di- (2-ethyl-4-nonylphenyl) amine; alkylphenyl-1-naphthylamines, such as octylphenyl-1-naphthylamine and N-tert-dodecylphenyl-1-naphthylamine, 1-naphthylamine; arylnaphthylamines such as phenyl-1-naphthylamine, phenyl-2-naphthylamine, N-hexylphenyl-2-naphthylamine N, N′-octylphenyl-2-naphthylamine; phenylenediamines such as N, N′-diisopropyl-n-phenylenediamine; and N, N′-diphenyl-n-phenylenediamine and phenothiazines such as phenothiazine (manufactured by Hodogaya Chemical Ltd.) and 3,7-dioctylphenothiazine.

Along with the amine-based antioxidants used in the present invention, phenolic antioxidants can be used. In the examples mentioned below, phenolic antioxidants and amine-based antioxidants are used in combination. These antioxidants can be used individually or in numerous combinations, ranging from 0.01 to 5% (wt.) In the composition of the lubricating oil.

The combination of amine and phenolic antioxidant antioxidants used in the examples is shown in Table 1.

Examples of sulfur-based antioxidants include dialkyl sulfides, such as didodecyl sulfide, thiodipropionic acid esters, such as dioctadecyl thiodipropionate, dimyristyl thiodipropionate and dodecylctadecyl thiodipropionate, and 2-mercaptobenzimidazole.

Phenolic antioxidants include 2-tert-butylphenol, 2-tert-butyl-4-methylphenol, 2-tert-butyl-5-methylphenol, 2,4-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol , 2-tert-butyl-4-methoxyphenol, 3-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone (called Antage DBH manufactured by Kawaguchi Chemical Industry Co. Ltd.), 2,6- di-tert-butylphenol, 2,6-tert-butyl-4-alkylphenols, such as 2,6-ditret-butyl-4-methylphenol and 2,6-ditret-butyl-4-ethylphenol and 2,6-di -7 thyrea 7-butyl-4-alkoxyphenols, such as 2,6-di-tert-butyl-4-methoxyphenol and 2,6-di-tert-butyl-4-ethoxyphenol.

In addition, these include 3,5-di-tert-butyl-4-hydroxybenzylmercapto-octyl acetate, alkyl 3- (3,5-di-diuret-butyl-4-hydroxyphenyl) propionates, such as n-octadecyl- 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (called Yoshinox SS manufactured by Yoshitomi Fine Chemicals Ltd.), n-dodecyl-3- (3,5-di-tert-butyl-4 -hydroxyphenyl) propionate and 2′-ethylhexyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, benzenepropanoic acid 3,5-bis (1,1-dimethyl-ethyl) -4-hydroxy- C ₇ -C ₉ -alkyl (side chain) ester (named Irganox L135 manufactured by Ciba Specialty Chemicals Ltd.), 2,6-di-tert-butyl-α-dimethylamino-n-k resol and 2,2′-methylene bis (4-alkyl-6-tert-butylphenol) s, such as 2,2′-methylene bis (4-methyl-6-tert-butylphenol) (called Antage W- 400 manufactured by Kawaguchi Chemical Industry Ltd.) and 2,2′-methylene bis (4-ethyl-6-tert-butylphenol) (named Antage W-500 manufactured by Kawaguchi Chemical Industry Ltd).

In addition, there are bisphenols such as 4,4′-butylidene bis (3-methyl-6-tert-butylphenol) (called Antage W-300 from Kawaguchi Chemical Industry Ltd.), 4,4′-methylene bis (2,6-di-tert-butylphenol) (under the name Ionox 220AN manufactured by Shell Japan Ltd.), 4,4′-bis (2,6-di-tert-butylphenol), 2,2- (di -n-hydroxyphenyl) propane (called Bisphenol A manufactured by Shell Japan Ltd.), 2,2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 4,4′-cyclohexylidene bis ( 2,6-tert-butylphenol), hexamethylene glycol bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (under the name Irganox L109 manufactured by Ciba Specialty Chemicals Ltd.), triethyl phenol glycol bis [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] (under the name Tominox 917 manufactured by Yoshitomi Fine Chemicals Ltd.), 2,2′-thio- [diethyl-3- (3 , 5-di-tert-butyl-4-hydroxyphenyl) propionate (called Irganox LI 15 manufactured by Ciba Specialty Chemicals Ltd.), 3,9-bis {1,1-dimethyl-2- [3- (3-tert -butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl} 2,4,8,10-tetraoxaspiro [5.5] undecane (called Sumilizer GA80 manufactured by Sumitomo Chemicals), 4,4′-thio-bis ( 3-methyl-6-tert-butyl phenol) (under the name Antage RC manufactured by Kawaguchi Chemical Industry Ltd.) and 2,2′-thiobis (4,6-di-diureth-butylresorcinol).

Polyphenols such as tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane (called Irganox L101 from Ciba Specialty Chemicals Ltd.), 1,1,3- may also be mentioned. tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane (called Yoshinox 930 manufactured by Yoshitomi Fine Chemicals Ltd.), 1,3,5-trimethyl-2,4,6-tris (3,5 -di-tert-butyl-4-hydroxybenzyl) benzene (called Ionox 330 manufactured by Shell Japan Ltd.), glycol ester and bis- [3,3′-bis- (4′-hydroxy-3′-tert- butylphenyl) butyric acid], 2- (3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) methyl-4- (2 ″, 4 ″ - di-tyreth-butyl-3 ″ - hydroxyphenyl) methyl- 6-tert-butylphenol and 2,6-bis (2′-hydroxy-3′-tert-butyl-5′-methylbenzyl) -4-methylphenol and phenol and aldehyde condensates such as n-tert-butyl phenol and formaldehyde condensates and condensates of n-tert-butylphenol and acetaldehyde.

In addition to the above components, in cases where it is necessary for applications or performance characteristics, it can also be used as appropriate metal deactivators, corrosion inhibitors, additives that improve the viscosity index, additives that lower the pour point of oil, antifoam additives and other additives in the lubricating oil compositions for diesel engines of the present invention.

Metal deactivators that can be used with the diesel engine lubricant composition of the present invention include benzotriazole and benzotriazole derivatives, which are 4-alkylbenzotriazoles, such as 4-methylbenzotriazoles and 4-ethylbenzotriazoles, 5-alkylbenzotriazoles, such as 5-methyl benzotriazole and 5-ethyl benzotriazole, 1-alkylbenzotriazoles such as 1-dioctylaminomethyl-2,3-benzotriazole, and 1-alkyltolutriazoles such as 1-dioctylaminomethyl-2,3-tolutriazole, and benzimidazole and benzoic derivatives midazole, which are 2- (alkyldithio) benzoimidazoles, such as 2- (octyldithio) benzoimidazole, 2- (decyldithio) benzoimidazole and 2- (dodecyldithio) benzoimidazole and 2- (alkyldithio) toluimidazole, such as 2 toluimidazole, 2- (decyldithio) toluimidazole and 2- (dodecyldithio) toluimidazole.

Mention may also be made of indazole, indazole derivatives which are toluindazoles, such as 4-alkylindazoles and 5-alkylindazoles, benzothiazole and benzothiazole derivatives, which are 2-mercaptobenzothiazole derivatives (under the name Thiolite B-3100 manufactured by Chiyoda Chemical Industries Ltd. ), 2- (alkyldithio) benzothiazoles, such as 2- (hexyldithio) benzothiazole and 2- (octyldithio) benzothiazole, 2- (alkyldithio) tolutiazoles, such as 2- (hexyldithio) tolutiazole, and 2- (octyldithio) tolutiazole, (N, N-dialkyl dithiocarbamyl) benzothiazoles such as 2- (N, N-diethyl dithioc arbamyl) benzothiazole, 2- (N, N-dibexyl dithiocarbamyl) benzothiazole and 2- (N, N-dihexyl dithiocarbamyl) benzothiazole, and 2- (N, N-dialkyl dithiocarbamyl) tolutiazoles such as 2- (N, N-tol-di-ethyl di , 2- (N, N-dibutyldithiocarbamyl) tolutiazole; and 2- (N, N-dihexyl dithiocarbamyl) tolutiazole.

In addition, benzoxazole derivatives, which are 2- (alkyldithio) benzoxazoles, such as 2- (octyldithio) benzoxazole, 2- (decyldithio) benzoxazole and 2- (dodecyldithio) benzoxazole, or which are 2- (alkyldithio) toluoxazoles, can be mentioned. such as 2- (octyldithio) toluoxazole, 2- (decyldithio) toluoxazole and 2- (dodecyldithio) toluoxazole, thiadiazole derivatives which are 2,5-bis (alkyldithio) -1,3,4-thiadiazoles, such as 2,5-bis (heptyldithio) -1,3,4-thiadiazole, 2,5-bis (nonyldithio) -1,3,4-thiadiazole, 2,5-bis (dodecyldithio) -1,3,4-thiadiazole and 2,5-bis (octadecyldithio) -1,3,4-thiadiazole, 2,5-bis (N, N-dialkyldithiocarbamyl) -1,3,4-thiadiazoles such as 2,5-bis (N, N- diethyldithiocarbamyl) -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 and 2-N, N-dialkyldithiocarbamyl-5-mercapto-1,3,4-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, which are, for example, 1-alkyl-2,4-triazoles, such as 1-di (octylaminomethyl) -2,4- triazole.

These metal deactivators can be used individually or in numerous combinations, and their content in the lubricating oil composition is from 0.01 to 0.5% (wt.).

Examples of the aforementioned corrosion inhibitors include fatty acids, partial alkenyl succinic esters, fatty acid soaps, alkyl sulfonic acid salts, alkaline earth metal sulfonates and naphthenates (calcium (Ca), magnesium (Mg), barium (Ba), and the like. ), esters of fatty acids and polyhydric alcohols, amines of fatty acids, paraffin oxide and alkyl polyoxyethylene ethers, and usually their amount in the mixture is from 0.1 to 5% (wt.) based on the total amount of the composition.

In order to improve the low temperature flow characteristics and viscosity characteristics, additives that lower the pour point of the oil and additives that improve the viscosity index can be added to the lubricating oil composition of the invention.

Examples of viscosity index improvers include non-dispersive viscosity index improvers, such as polymethacrylates, as well as ethylene-propylene copolymers, styrene-diene copolymers, such as styrene-butadiene or olefin polymers, such as polyisobutylene and polystyrene, and dispersant-type viscosity index improvers, where nitrogen-containing monomers are copolymerized with them. As for the amount to be added, such additives can be used in the range from 0.05 to 20% (wt.) By weight of the lubricating oil composition.

As examples of additives that lower the pour point of oil, polymers based on polymethacrylate can be mentioned. As for the amount to be added, these additives can be used in the range from 0.01 to 5% (wt.) By weight of the lubricating oil composition. A polymethacrylate-based oil lowering additive was included in an example of the present invention.

In order to impart anti-foaming characteristics to the lubricating oil composition of the invention, anti-foaming additives may be added. Examples of preferred antifoam additives include organosilicates, such as polydimethylsiloxane, diethylsilicate, fluorosilicon, and non-silicone type antifoam additives, such as polyalkyl acrylates. As for the added amount, such additives can be used individually or in numerous compositions, and their content in the lubricating oil composition is from 0.0001 to 0.1% (wt.).

A further explanation is given below by way of examples and comparative examples, but the invention is not limited to examples.

In preparing the examples and comparative examples, the following compositions and substances were used.

1. Base oils

(1-1) Base oil A: base oil obtained by Fischer-Tropsch synthesis (XHVI 5.2) [Characteristics: kinematic viscosity at 100 ° C, 5.2 mm ² / s; viscosity index 140; sulfur content - not more than 10 ppm (wt.)].

(1-2) Base oil B: Fischer-Tropsch derived base oil (XHVI 8.2) [Characteristics: kinematic viscosity at 100 ° C, 8.2 mm ² / s; viscosity index 144; sulfur content - not more than 10 ppm (wt.)].

(1-3) Base oil C: Co-oligomer of ethylene and α-olefins (Lucant HC40) [Characteristics: kinematic viscosity at 100 ° C, 40 mm ² / s; viscosity index - 155; sulfur content - not more than 10 ppm (wt.)].

2. Zinc dithiophosphates

(2-1) ZnDTP-1: Zinc dialkyldithiophosphate containing secondary alkyl groups with 3-6 carbon atoms [Components (elemental analysis values): Zn 11.1% (wt.), P 10.0% (wt.), S 21% (wt.)].

(2-2) ZnDTP-2: Zinc dialkyldithiophosphate containing secondary alkyl groups with 4-6 carbon atoms [Components (elemental analysis values): Zn 7.7% (wt.), P 7.2% (wt.), S 15% (wt.)].

3. Ashless dispersants

(3-1) Succinimide-1: Boron-containing polybutenylsuccinimide (mono) [Components (elemental analysis values): N 2.2% (wt.), B 1.96% (wt.)]

(3-2) Succinimide-2: Polybutenylsuccinimide (bis) [Components (elemental analysis values): N 1.2% (wt.)].

(3-3) Succinimide-3: Boron-containing polybutenylsuccinimide (bis) [Components (elemental analysis values): N 1.5% (wt.), 0.47% (wt.)].

4. Antioxidants

(4-1) Antioxidant-1: Amine-based antioxidant (Irganox L57) [Components: nitrogen content 4.5% (wt.)].

(4-2) Antioxidant-2: An antioxidant based on shielded (stereophonic) phenol (Irganox L135).

5. Metal deactivator: Derived benzotriazole (Irgamet 39).

6. Viscosity Index Improving Agent: Butadiene-styrene based viscosity index improver.

7. Additive that lowers the pour point of oil: an additive that lowers the pour point of oil based on polymethacrylate.

8. Anti-foaming additive: anti-foaming additive based on polydimethylsiloxane.

Examples and comparative examples

The component substances are mixed in the ratios shown in tables 1 and 2, and get the composition of lubricating oils for use in diesel engines. The ratios shown in tables 1 and 2 are expressed in% (wt.), Unless otherwise indicated.

Testing

The following types of testing are carried out on the compositions of examples 1-4 and comparative examples 1-6 in order to compare their characteristics.

(1) Calculation of parameters

The total value of the parameter [(amount of zinc in zinc dialkyldithiophosphate) × (amount of nitrogen in polybutenylsuccinimide)] and [(amount of zinc in zinc dialkyldithiophosphate) × (amount of nitrogen in amine-based antioxidant)]

The amounts of zinc and nitrogen described herein are expressed in% (wt.).

Evaluation Criteria:

0.015 or more Acceptable less than 0.015 Unacceptably

If the indicated value is less than 0.015, the TGF will exceed 30% or the wear of the cam protrusion will exceed 95 μm, which is undesirable. If this value is from 0.015 to 0.06, both the TGF and the wear of the cam protrusion will be small; this means that you can achieve the desired results. If the above value is more than 0.06, this is not favorable from the point of view of economic efficiency.

(2) Detergency testing based on TGF value (TGF value measured after Nissan TD25 engine test).

The test for evaluating the washing ability for a piston is carried out using the JASO M336: 1998 engine oil washing test, which is a diesel engine washing test, also adopted for the JASO M355 (Automotive Diesel Engine Oil Standard).

Evaluation Criteria:

30% or less Acceptable Over 30% Unacceptably

(3) Valve wear tests

Valve wear is tested in accordance with the JASO M354: 1999 valve wear test method (using the Mitsubishi 4D34T4 engine) ..

Evaluation Criteria:

Cam lug wear 95 μm or less Acceptable Over 95 mct Unacceptably

The wear limit of the cam lug is based on the JASO DH-2 test criteria,

In the case of values of wear of the working protrusion of the cam used here, conduct research using their actual measured values, and do not carry out any transformations.

Test results

The test results for examples 1-4 and comparative examples 1-6 are shown in tables 1 and 2.

Discussion

The composition of example 1 did not contain any metal-containing detergents. The amount of nitrogen from the ashless dispersant of succinimide-3 was 0.15% (wt.), The amount of nitrogen from the amine-based antioxidant was 0.08% (wt.), The amount of boron from the dispersant based on succinimide was 0.047% (wt.), and at the same time, the amount of Zn from ZnDTP was 0.10% (wt.), so the parameter [amount of zinc × (amount of nitrogen from succinimide + amount of nitrogen of antioxidant based on amine)] had a value of 0.023, a TGF of 12% and the wear of the cam protrusion was 7 μm. In addition, the sulfate ash content was 0.23% (wt.), Which meets the criterion, so that satisfactory characteristics were obtained.

No metal-containing detergents were used in the composition of Example 2. The main points were the total amount of nitrogen from the mixture of succinimide-1, succinimide-2 and succinimide-3, which gave a total amount of nitrogen of 0.12% (wt.), And the parameter value was therefore 0.020. The TGF value was 12% and the wear of the cam protrusion was 18 μm, which meant satisfactory performance was obtained.

In the case of example 3, the amount of nitrogen of succinimides was 0.15% (wt.), And it was a mixture of succinimide-1 and succinimide-2. The amount of Zn was 0.1% (wt.), And the amount of nitrogen of the amine-based antioxidant was 0.0396% (wt.), Which means that the parameter value was 0.019. The TGF value was 9% and the wear of the cam protrusion was 24.7 μm.

When the amount of nitrogen from the amine-based antioxidant was 0.022% (wt.), As in Example 4, the parameter value was 0.015. The TGF value was 7% and the wear of the cam protrusion was 84.9 μm, but these values are in the range corresponding to satisfactory performance.

On the other hand, in the case of comparative example 1, the amount of nitrogen from the dispersant based on succinimide was 0.075% (wt.). In addition, the amount of Zn was 0.077% (wt.), And the amine-based antioxidant was not added, so the parameter value significantly decreased to 0.006. The TGF value was 47% and the wear of the cam lug increased significantly. In comparative example 2, the amount of nitrogen from the succinimide-based dispersant was 0.12% (wt.), And the amount of nitrogen from the amine-based antioxidant was 0.08% (wt.), While the amount of Zn was 0.05% (wt.) .). This meant that the value of the parameter 0.010 was out of the interval, and the TGF value was 39%, but the wear of the working protrusion of the cam exceeded 95 μm at 217 μm.

In comparative example 3, the zinc content was 0.05% (wt.), The amount of nitrogen from succinimide was 0.10% (wt.), The amount of nitrogen from the amine-based antioxidant was 0.0792% (wt.), And the parameter value was 0.009, which is out of range. The TGF value was 55, and the valve mechanism wear further deteriorated to 300 μm. In the case of comparative example 4, where the amount of Zn was 0.06% (wt.), The amount of nitrogen from succinimide was 0.15% (wt.), The amount of nitrogen from the amine-based antioxidant was 0.0396% (wt.), the parameter value was 0.011, the TGF value was 14%, and the wear of the cam protrusion exceeded 95 μm at 130.7 μm.

In comparative example 5, where the amount of Zn was 0.07% (wt.), The amount of nitrogen from succinimide was 0.12% (wt.), The parameter value was 0.011, the TGF value was satisfactory at 24%, but the wear of the cam protrusion increased significantly and amounted to 235.6 microns. In comparative example 6, the amount of succinimide-3 was the same as in example 1, and the amount of Zn was 0.07% (wt.), While the amount of nitrogen from the amine-based antioxidant was 0.0396% (wt.), This meant that the parameter value was 0.013, the TGF value was 39%, and the wear of the cam lug was 99 μm, which slightly exceeded the wear limit for the cam shaft of 95 μm.

Table 1 Example 1 Example 2 Example 3 Example 4 Component Base oil A 16.5 16.1 35 36.3 Base oil B 65.6 68,4 36.8 36,2 Base oil C fourteen fourteen ZnDTP-1 0.9 0.9 Zndtp-2 1.3 1.15 Succinimide-1 1,2 2,4 Succinimide-2 1,6 8.1 Succinimide 3 10 5 10 Antioxidant 1 1.8 1.8 0.9 0.5 Antioxidant 2 0.5 0.5 1,5 1,5 Metal deactivator 0.2 0.1 0.05 Viscosity index improver four four Additive lowering the pour point of oil 0.3 0.3 0.3 0.3 Antifoam additive 10 ppm 0.02 ppm 0.03 ppm 0.03 ppm Elemental analysis (%, wt.) Ca 0 0 0 0 Zn 0,1001 0,0999 0,0999 0,08855 R 0.0936 0.09 0.09 0.0828 S 0.195 0.20151 0.20151 0.1725 N in succinimides 0.15 0,1206 0.15 0.15 N in antioxidant 0,0792 0,0792 0,0396 0,022 S in base oil 0 0 0 0 In in succinimides 0,047 0,047 0,047 0,047 Sulphated Ash 0.23 0.22 0.22 0.22 Test results The calculated parameters 0,023 0,020 0.019 0.015 Washing ability (TGF)% 12 25 9 7 Valve wear, microns 7.0 18.0 24.7 84.9

table 2 Comp. Comp. Comp. Comp. Comp. Comp. example 1 example 2 example 3 example 4 example 5 example 6 Component Base oil A 37.8 16.1 16 16 36.53 16 Base oil B 40.35 69.05 69.55 66.32 38 66.28 Base oil C fourteen fourteen ZnDTP-1 0.45 Zndtp-2 one 0.65 0.78 0.92 0.92 Succinimide-1 1,2 1,2 1,2 Succinimide-2 1,6 1,6 Succinimide 3 5 5 5 10 5 10 Antioxidant 1 1.8 1.8 0.9 0.9 0.9 Antioxidant 2 1,5 0.5 1,5 1,5 1,5 1,5 Metal deactivator 0.05 0.2 0.05 0.1 Viscosity index improver four four four four Temperature Reducing Additive 0.3 0.3 0.3 0.3 0.3 0.3 oil hardening Antifoam additive 0.03 ppm 10 ppm 0.02 ppm 0.03 ppm 0.03 ppm 0.03 ppm Elemental analysis (%, wt.) Sa 0 0 0 0 0 0 Zn 0,077 0.04995 0,05005 0,06006 0,07084 0,07084 R 0,072 0,045 0.0468 0.05616 0,06624 0,06624 S 0.15 0,10075 0.0975 0.117 0.138 0.138 N in succinimides 0,075 0,1206 0,1014 0.15 0,1206 0.15 N in antioxidant 0 0,0792 0,0792 0,0396 0,0396 0,0396 S in base oil 0 0 0 0 0 0 In in succinimides 0,0235 0,047 0,047 0,047 0,047 0,047 Sulphated Ash 0.21 0.19 0.19 0.20 0.02 0.20 Test results The calculated parameters 0.006 0.010 0.009 0.011 0.011 0.013 Washing ability (TGF)% 47 39 55 fourteen 24 eleven Valve wear microns 478.6 217.4 300.8 130.7 235.6 99.1

Claims (4)

1. The lubricating oil composition for use in diesel engines, which contains in the base oil no more than 0.3% (wt.) Sulphated ash, from 0.01 to 0.2% (wt.) Nitrogen in succinimides, from 0.05 up to 0.12% (wt.) of zinc in zinc dithiophosphates, from 0.02 to 0.3% (wt.) of nitrogen in amine-based antioxidants and from 0.01 to 0.08% (wt.) of boron, which in addition, it has the total value of the parameter [(amount of zinc in zinc dithiophosphates) × (amount of nitrogen in succinimides)] and [(amount of zinc in zinc dithiophosphates) × (amount of nitrogen in amine-based antioxidants)], vlyayuschee not less than 0,015, the composition does not contain phenolate or salicylate metal sulfonate detergents. 2. The lubricating oil composition according to claim 1, where the aforementioned oil is one base oil or a mixture of base oils selected from group II, group III, group IV and group V, and where the sulfur content of the base oil component is not more than 50 m d. 3. The lubricating oil composition according to claim 1 or 2, in which the washing ability (TGF) according to the method of testing the washing ability of motor oils JASO M336: 1998 is not more than 30%, and the wear of the valve mechanism, determined by the method of testing the wear of the valve mechanism JASO M354: 1999, is not more than 95 microns. 4. The lubricating oil composition according to claim 1 or 2, in which the aforementioned oil contains secondary zinc alkyldithiophosphates, the alkyl groups of which contain from 3 to 12 carbon atoms.