JP2007169639A - Lubricating oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating oil composition giving reduced catalyst poisoning while keeping the abrasion suppressing effect. <P>SOLUTION: The lubricating oil composition contains (a) an oil of lubricating viscosity, (b) a mixture of overbased potassium cleaning agent and overbased calcium cleaning agent, (c) an antioxidation agent, (d) a succinimide derivative dispersing agent and (e) an antiabrasive additive (the lubricating oil has a phosphorus content of ≤0.12 mass% and is free from dialkyl carboxylate) or contains (a) an oil of lubricating viscosity, (b) a mixture of overbased potassium monoalkylcarboxylate and overbased calcium alkylarylsulfonate, (c) an amine-containing antioxidation agent, (d) ethylene carbonate-treated succinimide dispersing agent and (e) a phosphorus-containing antiabrasive additive (the lubricating oil composition has a potassium content of ≤0.1 mass% and a phosphorus content of ≤0.12 mass% and is free from dialkyl carboxylate). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a lubricating oil composition comprising the following components: (a) a major amount of oil of lubricating viscosity, (b) a mixture of an overbased potassium detergent and an overbased calcium detergent, (c) one (D) one or more succinimide derivative dispersants, and (e) one or more antiwear additives [provided that the lubricating oil composition contains more than 0.12% by mass of phosphorus. And the lubricating oil composition does not contain a dialkylcarboxylate detergent].
The present invention also relates to a lubricating oil composition comprising the following components: (a) an oil of lubricating viscosity, (b) a mixture of an overbased potassium monoalkylcarboxylate and an overbased calcium alkylaryl sulfonate, (C) one or more antioxidants, (d) an ethylene carbonate-treated succinimide dispersant, and (e) one or more antiwear additives [provided that the lubricating oil composition contains 0.12% by mass of phosphorus. Not much and the lubricating oil composition does not contain a dialkylcarboxylate detergent].
Furthermore, the present invention also relates to a method for reducing catalyst poisoning in an exhaust gas aftertreatment device of an internal combustion engine, comprising operating the internal combustion engine using the lubricating oil composition of the present invention.

  Future diesel engines will be equipped with exhaust aftertreatment devices that allow them to follow future exhaust gas legislation. Some of these devices have proven to be sensitive to the fuel and lubricant combustion products used in the engine. Some devices are sensitive to phosphorus from lubricants, other devices are sensitive to sulfur from both fuel and lubricants, and other devices are sensitive to sulfated ash from fuel and lubricant combustion. Sensitive. In order to guarantee the durability of these various types of aftertreatment devices, special lubricants characterized by low levels of sulfated ash, sulfur and phosphorus have been developed. The most common of these lubricants result in low sulfate ash levels with reduced sulfur and phosphorus. Less common are low phosphorus or phosphorus free lubricants that use certain, mostly sulfur or molybdenum based zinc dialkyldithiophosphate substitute additives.

  The guidelines for lubricants for low emission internal combustion engines that will be commercialized in 2007 and 2008 are as follows: (1) Sulfated ash content equals or equals 1.0% by weight in diesel engine lubricants Lower, must be less than or equal to 0.5% by weight for passenger car diesel engine lubricants, (2) depending on the engine manufacturer, the sulfur content of the lubricant must be less than 0.2% by weight However, another engine manufacturer allows up to 0.4% by weight, and (3) some engine manufacturers require that the maximum amount of phosphorus be 0.08% by weight, while another Engine manufacturers have found phosphorus up to 0.12% by weight. The reduction in sulfated ash reduces the gap between diesel engine lubricants and gasoline and natural gas engine lubricants, thereby expanding the use of low phosphorus, low sulfur and low sulfated ash engine lubricants. And natural gas engine lubricants.

  First generation low emission internal combustion engine lubricants were formulated to meet the above guidelines using low levels of detergent and zinc dialkyldithiophosphate. However, there is a prediction that at some point in the future, the maximum sulfur and phosphorus content will be much lower than we would expect from the industry to go between now and 2010. Low phosphorus lubricants were expected to provide some wear protection but were also expected to harm the oxidation catalyst. In an effort to explore the possibility of reducing catalyst poisoning while maintaining wear control, we have developed a pilot lubricant containing a mixture of overbased potassium and overbased calcium detergents. When these experimental lubricants using a mixture of overbased potassium monoalkylcarboxylate and overbased calcium alkylaryl sulfonate were used in an internal combustion engine for catalyst poisoning measurements, the results were predicted. What was not obtained was a reduction in catalyst poisoning compared to lubricants using detergents other than those used in the lubricants of the present invention. Since the phosphorus content of the lubricating oil of the present invention was twice that of the comparative lubricating oil, a mixture of overbased potassium monoalkylcarboxylate and overbased calcium alkylaryl sulfonate was added to the lubricating oil composition. This result was surprising because it showed that catalyst poisoning could be reduced while maintaining wear inhibition.

  Methods for reducing catalyst poisoning by reducing the phosphorus content of the lubricating oil are described in numerous patent documents and patent applications, all of which include (a) a major amount of oil of lubricating viscosity, and (b ) A mixture of an overbased potassium monoalkylcarboxylate and an overbased calcium alkylaryl sulfonate, (c) one or more antioxidants, (d) one or more derivatized succinimides (ie, succinimide derivatives) There is no disclosure of a lubricating oil composition comprising a)) dispersant and (e) one or more antiwear additives. The lubricating oil of the present invention, despite containing phosphorus, provides a significant reduction in catalyst poisoning while maintaining excellent wear control.

  Patent Document 1 discloses a low ash low phosphorus motor oil with improved oxidative stability as a result of adding a synergistic amount of a dialkyldiphenylamine antioxidant and a sulfurized polyolefin. The synergy between the two additives compensates for the decrease in phosphorus content in the form of zinc dithiophosphate to the extent that the oil retains its SE quality rating.

  Patent Document 2 discloses an overbased additive containing potassium sulfonate suitable for use in lubricants and fuels, and a method for producing them. The TBN of the sulfonate is at least 250 milligrams KOH per gram.

  In Patent Document 3, (a) an alkylphenol is neutralized with an alkali metal hydroxide, (b) the product is carboxylated with carbon dioxide, and the initial alkali metal alkylphenate is converted into an alkali metal alkyl salicylate. (C) an alkyl salicylate-containing detergent dispersant for lubricating oil obtained by (c) sulfidizing-peralkalating the product in the presence of an alkaline earth base and then carbonating the product with carbon dioxide Is disclosed.

  Patent Document 4 discloses a low phosphorus motor oil for passenger cars containing an oil of lubricating viscosity as a main component and a trimetallic detergent mixture as a minor component, wherein the trimetallic detergent mixture is at least one overbased calcium metal detergent. And a trimetallic detergent mixture in the lubricating oil composition, wherein the total TBN imparted to the oil is from about 2 to about TBN, comprising at least one overbased magnesium metal detergent and at least one overbased sodium metal detergent. A motor oil present in an amount such as 12 is disclosed.

  Patent Document 5 discloses a sodium-free non-thixotropic lubricating oil additive having 10% to 50% liquid organic diluent and 30% to 90% substituted hydrocarbon metal salt. At least 30 mol% of the metal of the metal salt is lithium, and the salt is essentially free of sodium. The non-thixotropic lubricating oil additive has a BN of 150 or less with lithium. This additive is useful for reducing black sludge deposits and piston deposits.

  Patent Document 6 discloses a lubricating oil additive and a lubricating oil composition that exhibit excellent storage stability without generating precipitates even when a combination of a salicylate detergent and another metal detergent is used. . What is mixed with the lubricating base oil is (A) an alkali metal or alkaline earth metal salicylate and an overbased salt having a hydrocarbon group having 1 to 40 carbon atoms at the 3- and 5-positions, and (B) It is a metal detergent that is not any salicylate detergent.

  Patent Document 7 describes a base oil of lubricating viscosity, (a) at least one oil-soluble lithium-free overbased alkali or alkaline earth metal-containing overbased detergent, and (b) a TBN generally from 240 to 400. A lubricating oil additive concentrate comprising at least one oil-soluble overbased lithium salt detergent in the range is disclosed.

  Patent Document 8 discloses a lubricating oil composition containing at least one overbased alkali metal detergent as a lubricating oil additive effective for lubricating mechanical parts of land and marine engines. The overbased alkali metal detergent may be sulfurized and may contain at least 80% by weight alkyl hydroxybenzoate and the preferred alkali metal is potassium. This lubricating oil composition provides improved thermal stability and black sludge deposit control.

  Patent Document 9 discloses a method for improving brake and clutch performance of a functional fluid, which comprises adding an amount of friction-reducing polyalkenyl sulfonate to the functional fluid, wherein the polyalkenyl sulfonate is an alkylvinylidene and 1,1 Disclosed is a process that is an alkali metal or alkaline earth metal salt of a polyalkylene sulfonic acid derived from a mixture of polyalkylenes containing greater than about 20 mole percent dialkyl isomers.

  Patent Document 10 discloses a lubricating oil effective for lubricating mechanical parts of land and marine engines such as hydraulic systems and transmissions, two-stroke and four-stroke vehicle engines, trunk pistons and two-stroke crosshead marine engines. An overbased detergent is disclosed as an additive. This overbased detergent provides improved cleanliness and thermal stability performance compared to highly overbased sulfonates. Furthermore, the miscibility with commercial phenates is better than conventional sulfonates.

Patent Document 11 discloses a composition containing at least one basic alkali metal salt of an acidic organic compound substituted with at least one hydrocarbon, wherein the hydrocarbon group is from a polyalkylene having an M _n of at least 600. In the case where the organic compound is a sulfonic acid, the _Mn of the polyalkylene is at least 900, and the acidic organic compound is a hydrocarbon derived from a carboxylic acid and a polyalkylene having an _Mn of 900 or less. In the case of a mixture with an acidic organic compound containing a sulfonic acid having a group, the carboxylic acid is said to account for at least 10% of the equivalent of the mixture.

In US Pat. No. 6,057,059, the hydrocarbon backbone is derived from an ethylene alpha olefin (EAO) copolymer having a terminal vinylidene unsaturation of> 30% and an M _n of 500 to 7000 or an alpha olefin alone or a copolymer. Also disclosed is a lubricating oil containing certain ashless dispersants containing an oil soluble high molecular weight hydrocarbon backbone with functional groups in combination with an overbased alkali metal additive. In particular, crankcase lubricants that exhibit very good sludge and varnish control properties, provide excellent engine cleanliness and further oxidation resistance, and / or reduce the tendency to thicken due to interactions within the package About.

U.S. Pat. No. 4,304,420 U.S. Pat. No. 4,797,217 US Pat. No. 5,033,687 US Pat. No. 5,804,537 US Pat. No. 6,235,688 European Patent Application No. 03831288.2 (Publication No. EP 1580257A1) Specification European Patent Application No. 96301587.0 (Publication No. EP071159A2) Specification US Patent Application No. 10 / 744,871 (Publication No. US 2005/0137100 A1) Specification US Patent Application No. 10/714469 (Publication No. US 2004/0102339 A1) Specification US Patent Application No. 10/745125 (Publication No. US2005 / 0137098A1) Specification International Application No. PCT / US92 / 01476 (Publication No. WO92 / 18587) Pamphlet International Application No. PCT / EP95 / 02271 (Publication No. WO95 / 34619) Pamphlet

The present invention relates to a lubricating oil composition comprising the following components: (a) a major amount of an oil of lubricating viscosity, (b) a mixture of an overbased potassium detergent and an overbased calcium detergent, (c) one or more. (D) one or more succinimide derivative dispersants, and (e) one or more antiwear additives [provided that the lubricating oil composition does not contain more than 0.12 mass% phosphorus. And the lubricating oil composition does not contain a dialkylcarboxylate detergent].
The present invention also relates to a lubricating oil composition comprising the following components: (a) an oil of lubricating viscosity, (b) a mixture of an overbased potassium monoalkylcarboxylate and an overbased calcium alkylaryl sulfonate, c) one or more antioxidants, (d) ethylene carbonate-treated succinimide dispersant, and (e) one or more antiwear additives [wherein the lubricating oil composition contains more than 0.12% by weight of phosphorus. And the lubricating oil composition does not contain a dialkylcarboxylate detergent].
The present invention also relates to a method for reducing catalyst poisoning in an exhaust gas aftertreatment device for an internal combustion engine, the method comprising operating the internal combustion engine using the lubricating oil composition of the present invention.

That is, the present invention relates to a lubricating oil composition comprising the following components:
(A) a major amount of oil of lubricating viscosity;
(B) a mixture of an overbased potassium detergent and an overbased calcium detergent;
(C) one or more antioxidants,
(D) one or more succinimide derivative dispersants, and (e) one or more antiwear additives,
However, the lubricating oil composition does not contain more than 0.12% by weight phosphorus and the lubricating oil composition does not contain a dialkylcarboxylate detergent.

  The ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition of the present invention is in the range of about 0.5: 1.0 to about 10: 1. Preferably, the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition of the present invention ranges from about 1.0: 1.0 to about 7.5: 1.0. is there. More preferably, the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition of the present invention ranges from about 2.0: 1.0 to about 5.0: 1.0. It is in. Most preferably, the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition of the present invention is 3.5: 1.

  In the lubricating oil composition of the present invention described above, the concentration of potassium in the overbased potassium detergent is in the range of about 1.0% to about 10.0% by weight based on the total weight of the overbased potassium detergent. It is preferable that it exists in. More preferably, the concentration of potassium in the overbased potassium detergent is in the range of about 1.5% to about 7.5% by weight, more preferably, based on the total weight of the overbased potassium detergent. The concentration of potassium in the overbased potassium detergent is in the range of about 2.0% to about 5.0% by weight based on the total weight of the overbased potassium detergent. Most preferably, the concentration of potassium in the overbased potassium detergent is in the range of about 2.5% to about 3.0% by weight, based on the total weight of the overbased potassium detergent.

  The concentration of calcium in the overbased calcium detergent used in the lubricating oil of the present invention is in the range of about 1.0% to about 15.0% by weight based on the total weight of the overbased calcium detergent. Is preferred. More preferably, the overbased calcium detergent used in the lubricating oil of the present invention is in the range of about 2.0% to about 10.0% by weight based on the total weight of the overbased calcium detergent, Preferably, the overbased calcium detergent used in the lubricating oil of the present invention is in the range of about 3.0% to about 7.5% by weight based on the total weight of the overbased calcium detergent. Most preferably, the concentration of calcium in the overbased calcium detergent is in the range of about 4.0% to about 6.0% by weight, based on the total weight of the overbased calcium detergent.

  The phosphorus content of the lubricating oil composition of the present invention is preferably in the range of 0.03% to about 0.12% by weight based on the total weight of the lubricating oil composition. More preferably, the phosphorus content of the lubricating oil composition of the present invention is in the range of 0.05% to about 0.1% by weight based on the total weight of the lubricating oil composition. Most preferably, the phosphorus content of the lubricating oil composition of the present invention is in the range of 0.07 wt% to about 0.09 wt% based on the total weight of the lubricating oil composition.

  Examples of preferred medium overbased metal detergents that can be used in the lubricating oil compositions of the present invention include medium overbased alkyl aryl sulfonates, monoalkyl carboxylates / salicylate, sulfurized salicylates, or alkylphenols, aldehydes, and amines. There are Mannich condensation products. More preferred are medium overbased monoalkylcarboxylates and alkylaryl sulfonates. Preferably, the detergent is an alkali metal monoalkylcarboxylate and an alkaline earth metal alkylaryl sulfonate, more preferably the detergent is a medium overbased potassium monoalkylcarboxylate and a medium overbased calcium alkylaryl sulfonate. It is. Most preferably the detergent is a mixture of medium overbased potassium monoalkylcarboxylate and medium overbased calcium alkylaryl sulfonate. These detergents have a TBN greater than 1 and not greater than 200.

  Examples of preferred antioxidants used in the lubricating oils of the present invention include diphenylamine type compounds, including but not limited to alkylated diphenylamine, phenyl-alpha-naphthylamine, and alkylated-alpha-naphthylamine. Is mentioned. Antioxidants that can be used include esters of thiodicarboxylic acid, dithiocarbamates such as 15-methylenebis (dibutyldithiocarbamate), salts of dithiophosphoric acid, alkyl or aryl phosphate esters. Molybdenum compounds such as amine-molybdenum complex compounds and molybdenum dithiocarbamates can also be used as antioxidants, and hindered phenols such as 4,4′-methylene-bis (2,6-di-tert-butylphenol), 4,4′-bis (2,6-di-tert-butylphenol), 4,4′-bis (2-methyl-6-tert-butylphenol), 2,2′-methylene-bis (4-methyl-6) -T-butylphenol), 4,4'-butylidene-bis (3-methyl-6-t-butylphenol), 4,4'-isopropylidene-bis (2,6-di-t-butylphenol), 2,2 '-Methylene-bis (4-methyl-6-nonylphenol), 2,2'-isobutylidene-bis (4,6-dimethylphenol), 2,2'-5- Tylene-bis (4-methyl-6-cyclohexylphenol), 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,4-dimethyl- 6-t-butylphenol, 2,6-di-t-1-dimethylamino-p-cresol, 2,6-di-t-4- (N, N′-dimethylaminomethylphenol), 4,4′- Thiobis (2-methyl-6-tert-butylphenol), 2,2'-thiobis (4-methyl-6-tert-butylphenol), bis (3-methyl-4-hydroxy-5-t-10-butylbenzyl) -Sulphides and bis (3,5-di-tert-butyl-4-hydroxybenzyl) can also be used. More preferred are diphenylamine type compounds, most preferred are alkylated diphenylamines.

  A preferred dispersant that can be used in the lubricating oil composition of the present invention is an ashless dispersant. Examples of ashless dispersants include alkenyl succinimide as a derivative and alkenyl succinamide as a derivative. These dispersants can be derivatized, for example, by reaction with boron or ethylene carbonate. Ester ashless dispersants derived from long chain hydrocarbon-substituted carboxylic acids and hydroxy compounds can also be used. More preferred ashless dispersants are those derived from polyisobutenyl succinic anhydride, and most preferred are polyisobutenyl succinic anhydride derived dispersants treated with ethylene carbonate.

  Examples of antiwear additives include, but are not limited to, phosphate esters and thiophosphate esters and their salts, carbamates, esters, and molybdenum complexes. A preferred anti-wear additive contained in the lubricating oil composition of the present invention is a metal dialkyldithiophosphate. However, since the metal and phosphorus contribute to the lubricating oil, it can be said that it is advantageous to suppress the amount of this additive. Examples of metal dialkyldithiophosphates include zinc and molybdenum salts of dialkyldithiophosphates. The most preferred anti-wear additive used in the lubricating oil composition of the present invention is zinc dialkyldithiophosphate.

Another aspect of the invention relates to a lubricating oil composition comprising the following components:
(A) a major amount of oil of lubricating viscosity;
(B) a mixture of an overbased potassium monoalkylcarboxylate and an overbased calcium alkylaryl sulfonate;
(C) an amine-containing antioxidant,
(D) an ethylene carbonate-treated succinimide dispersant, and (e) a phosphorus-containing antiwear additive,
However, the lubricating oil composition does not contain more than 0.12% by weight phosphorus and the lubricating oil composition does not contain a dialkylcarboxylate detergent.

  In addition, the lubricating oil composition described above may contain one or more detergents different from those listed in (b) unless the detergent is a dialkylcarboxylate, and an antioxidant, dispersion different from those listed in (c) As long as the agent is a derivatized succinimide or succinamide, a different dispersant from that listed in (d), an anti-wear additive different from that listed in (e), a viscosity index improver, Ashless sulfur extreme pressure agent, alkaline earth metal and alkali metal borated extreme pressure agent, molybdenum-containing extreme pressure agent, pour point depressant, rust inhibitor, corrosion inhibitor, ash-containing friction modifier, ashless friction modifier One or more additives selected from agents, molybdenum-containing friction modifiers, metal deactivators, seal swelling agents, demulsifiers and antifoaming agents can be contained.

Another aspect of the invention relates to a lubricating oil concentrate comprising the following components:
(A) an oil having a lubricating viscosity of about 10% to about 90% by weight;
(B) a mixture of an overbased potassium detergent and an overbased calcium detergent;
(C) one or more antioxidants,
(D) one or more succinimide derivatives, and (e) one or more antiwear additives,
However, the lubricant concentrate does not contain more than 0.12% phosphorus and the lubricant concentrate does not contain dialkylcarboxylates.

  In addition, the above lubricating oil concentrate is composed of a viscosity index improver, an ashless sulfur extreme pressure agent, an alkaline earth metal and alkali metal borated extreme pressure agent, a molybdenum-containing extreme pressure agent, a pour point depressant, and a rust inhibitor. Contains one or more additives selected from corrosion inhibitors, ash-containing friction modifiers, ashless friction modifiers, molybdenum-containing friction modifiers, metal deactivators, seal swelling agents, demulsifiers and antifoaming agents You can also.

  The ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil concentrate of the present invention is in the range of about 0.5: 1.0 to about 10: 1. Preferably, the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil concentrate of the present invention ranges from about 1.0: 1.0 to about 7.5: 1.0. is there. More preferably, the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil concentrate of the present invention ranges from about 2.0: 1.0 to about 5.0: 1.0. It is in. Most preferably, the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil concentrate of the present invention is 3.5: 1.

Another aspect of the invention relates to a lubricating oil concentrate comprising the following components:
(A) a major amount of oil of lubricating viscosity;
(B) a mixture of overbased potassium monoalkylcarboxylate and overbased calcium alkylaryl sulfonate;
(C) an amine-containing antioxidant,
(D) an ethylene carbonate-treated succinimide dispersant, and (e) a phosphorus-containing antiwear additive,
However, the lubricating oil concentrate does not contain more than 0.12% phosphorus and the lubricating oil composition does not contain dialkylcarboxylates.

  The lubricating oil concentrate further comprises one or more detergents different from those listed in (b), as long as the detergent is not a dialkylcarboxylate, and an antioxidant or dispersant different from those listed in (c). As long as is a derivatized succinimide or succinamide, a dispersant different from that listed in (d), an anti-wear additive, a viscosity index improver different from those listed in (e), no Ash-sulfur extreme pressure agent, alkaline earth metal and alkali metal borated extreme pressure agent, molybdenum-containing extreme pressure agent, pour point depressant, rust inhibitor, corrosion inhibitor, ash-containing friction modifier, ashless friction modifier One or more additives selected from molybdenum-containing friction modifiers, metal deactivators, seal swelling agents, demulsifiers and antifoaming agents can be contained.

Yet another aspect of the present invention relates to a method for reducing catalyst poisoning in an exhaust gas aftertreatment device for an internal combustion engine, the method comprising operating the internal combustion engine using a lubricating oil composition comprising the following components: :
(A) a major amount of oil of lubricating viscosity;
(B) a mixture of an overbased potassium monoalkylcarboxylate and an overbased calcium alkylaryl sulfonate;
(C) an amine-containing antioxidant,
(D) an ethylene carbonate-treated succinimide dispersant, and (e) a phosphorus-containing antiwear additive,
However, the lubricating oil composition does not contain more than 0.12% by weight phosphorus and the lubricating oil composition does not contain a dialkylcarboxylate detergent.

  The ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition of the present invention is in the range of about 0.5: 1.0 to about 10: 1. Preferably, the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition of the present invention ranges from about 1.0: 1.0 to about 7.5: 1.0. is there. More preferably, the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition of the present invention ranges from about 2.0: 1.0 to about 5.0: 1.0. It is in. Most preferably, the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition of the present invention is 3.5: 1.

  In the method for reducing catalyst poisoning of the internal combustion engine, the internal combustion engine is a diesel engine, a gasoline engine, or a natural gas engine.

  Moreover, in the said aspect, as long as a detergent is not a dialkylcarboxylate, the lubricating oil composition is a different type of detergent from those listed in (b), an antioxidant different from that listed in (c), As long as the dispersant is a derivatized succinimide or succinamide, a different dispersant from that listed in (d), an anti-wear additive, a viscosity index improver different from those listed in (e) , Ashless sulfur extreme pressure agent, alkaline earth metal and alkali metal borated extreme pressure agent, molybdenum-containing extreme pressure agent, pour point depressant, rust inhibitor, corrosion inhibitor, ash-containing friction modifier, ashless friction One or more additives selected from a relaxation agent, a molybdenum-containing friction modifier, a metal deactivator, a seal swelling agent, a demulsifier, and an antifoaming agent can be contained.

  The lubricating oil composition of the present invention reduces catalyst poisoning while maintaining wear inhibition. In conventional lubricating oil compositions, wear suppression is achieved by adding a metal salt of a dialkyldithiophosphate such as zinc dialkyldithiophosphate. However, phosphorus in the dialkyldithiophosphate causes deactivation of the oxidation catalyst used in the exhaust gas aftertreatment device. The lubricating oil composition of the present invention results in reduced catalyst poisoning despite containing twice as much phosphorus as the comparative example. The prior knowledge is that the phosphorus-containing additive in the lubricating oil is detrimental to the catalyst, and what was not known is that the overbased potassium monoalkylcarboxylate and the overbased used in the lubricating oil composition of the present invention. This means that the mixture with the calcium hydroxide aryl sulfonate can reduce catalyst poisoning even in the presence of phosphorus.

  As used herein, the following terms have the following meanings unless otherwise indicated.

  “Alkali metal” as used herein means a Group IA metal of the periodic table, including lithium, sodium or potassium, with potassium being preferred.

  “Alkaline earth metal” as used herein means a Group II metal of the periodic table, including calcium, barium, magnesium and strontium, with calcium being preferred.

  “Aryl group” as used herein means a substituted or unsubstituted phenyl group.

  “Derivatized succinimide” as used herein means a derivative of succinimide derived from an alkenyl succinic anhydride, such as polyisobutenyl succinic anhydride. These dispersants can be further derivatized, for example, by reaction with boron or ethylene carbonate. Most preferred are polyisobutenyl succinic anhydride derived dispersants treated with ethylene carbonate.

  “Hydrocarbon group” as used herein means an alkyl or alkenyl group.

  “Overbased”, as used herein, is an alkali metal and alkaline earth metal alkylaryl sulfonate, wherein the ratio of the number of equivalents of alkali metal or alkaline earth metal to the number of equivalents of organic moiety is greater than 1. Mean big. Low overbasing means an alkali metal or alkaline earth metal alkylaryl sulfonate having a total base number (TBN) greater than 1 and less than or equal to 20, and medium overbasic is an alkali metal having a TBN greater than 20 and less than or equal to 200 Mean alkaline earth metal alkylaryl sulfonate. High overbasing means an alkali metal or alkaline earth metal alkylaryl sulfonate with a TBN greater than 200.

  “Total base number” or “TBN” as used herein means the amount of base equivalent to milligrams of KOH in a gram of sample. Therefore, the higher the TBN value, the stronger the alkalinity of the product, which reflects the higher alkalinity. The TBN was determined using the ASTM D2896 test.

  Unless otherwise specified, all percentages are weight percent.

[Lubricating oil composition]
The lubricating oil composition of the present invention can be produced by simply blending or mixing the compounds described in detail below. In order to facilitate blending of lubricating oil compositions containing the desired concentration of additives, these compounds can also be pre-blended as a concentrate or package in appropriate proportions with various other additives. it can.

(Oil of lubricating viscosity)
As used herein, an oil or base oil of lubricating viscosity means a lubricating oil, which may be a mineral oil or a synthetic oil of lubricating viscosity, but can preferably be used in a crankcase of an internal combustion engine. Is. The viscosity of the crankcase lubricant is typically about 1300 centistokes at -17.8 ° C to 22.7 centistokes at 98.9 ° C.

Lubricating oils can be derived from synthetic or natural sources. Mineral oils used as base oils in the present invention can include paraffinic, naphthenic, and other oils commonly used in lubricating oil compositions. Synthetic oils include hydrocarbon synthetic oils and synthetic esters. Synthetic hydrocarbon oils that can be used include liquid polymers of alpha-olefins having the proper viscosity. Particularly useful are hydrogenated liquid oligomers of C ₆ -C ₁₂ alpha-olefins such as 1-decene trimer. Similarly, alkylbenzenes of the proper viscosity, such as didodecylbenzene, may be used. Synthetic esters that can be used include esters of monocarboxylic acids and polycarboxylic acids with monohydroxyalkanols and polyols. Representative examples include didodecyl adipate, pentaerythritol tetracaproate, di-2-ethylhexyl adipate, and dilauryl sebacate. Complex esters synthesized from mixtures of mono and dicarboxylic acids and mono and dihydroxy alkanols can also be used.

  A blend of hydrocarbon oil and synthetic oil may be used. For example, blends of 10% to 25% by weight of hydrogenated 1-decene trimer with 75% to 90% by weight of 683 centistokes mineral oil at 37.8 ° C. Become. A Fischer-Tropsch derived base oil may also be used in the lubricating oil composition of the present invention.

  Further, it is conceivable that the oil of lubricating viscosity used for producing the lubricating oil composition of the present invention is a low sulfur base oil. The use of a low sulfur base oil helps to obtain a lubricating oil composition having a very low sulfur content. The sulfur content of the base oil is well known to those skilled in the art, so a low sulfur base oil can be selected as appropriate for the present invention.

(Medium overbased metal detergent)
Examples of preferred low and medium overbased metal detergents that can be used in the lubricating oil compositions of the present invention include medium overbased alkyl aryl sulfonates, carboxy, unless the carboxylate / salicylate is a dialkyl carboxylate / salicylate. There are rate / salicylate, sulfurized salicylate, or Mannich condensation products of alkylphenols, aldehydes and amines. More preferred are medium overbased monoalkylcarboxylates and alkylaryl sulfonates. These detergents may be alkali metal detergents or alkaline earth metal detergents as long as the alkali metal is not lithium. Preferred are alkali metal monoalkylcarboxylates and alkaline earth metal alkylaryl sulfonates, and more preferred are medium overbased potassium monoalkylcarboxylates and medium overbased calcium alkylaryl sulfonates. Most preferred is a mixture of medium overbased potassium monoalkylcarboxylate and medium overbased calcium alkylaryl sulfonate. These detergents have a TBN greater than 1 and not greater than 200.

  The concentration of potassium in the overbased potassium detergent used in the lubricating oil of the present invention is in the range of about 0.5% to about 5.0% by weight based on the total weight of the overbased potassium detergent. Is preferred. More preferably, the concentration of potassium in the overbased potassium detergent is in the range of about 1.0% to about 4.0% by weight based on the total weight of the overbased potassium detergent. Most preferably, the concentration of potassium in the overbased potassium detergent is in the range of about 1.5% to about 3.0% by weight, based on the total weight of the overbased potassium detergent.

  The concentration of calcium in the overbased calcium detergent used in the lubricating oil of the present invention is in the range of about 1.0% to about 9.0% by weight based on the total weight of the overbased calcium detergent. Is preferred. More preferably, the concentration of calcium in the overbased calcium detergent is in the range of about 2.0% to about 7.0% by weight based on the total weight of the overbased calcium detergent. Most preferably, the concentration of calcium in the overbased calcium detergent is in the range of about 3.0% to about 6.0% by weight, based on the total weight of the overbased calcium detergent.

  A preferred detergent mixture, a mixture of medium overbased potassium monoalkylcarboxylate and medium overbased calcium alkylaryl sulfonate, is an example of US patent application Ser. No. 10 / 745,125 (Publication No. 2005/0137098). 9 can be prepared using the methods described below in 9 or any method known to those skilled in the art.

  Method for producing a mixture of medium overbased potassium monoalkylcarboxylate and medium overbased calcium alkylaryl sulfonate

1) Premixing 473.8 g of xylene was placed in a four-necked reactor with stirring at 350 rpm under reduced pressure, followed by 568.6 g of xylene, 92.5 g of methanol (1) and 96.3 g of lime (1). Add the resulting lime slurry.
Total xylene (1) = 1042.4 g

2) Neutralization of alkyl aryl sulfonic acid Alkyl chain is C ₂₀ -C ₂₄ linear alpha olefin (trade name Alpha Olefin C ₂₀ -C ₂₄ , Chevron Phillips Chemical Company) 120 g of alkylaryl sulfonic acid (made by CPC) is added to the premix obtained above. The reaction medium is preheated to 50 ° C. over 20 minutes and then remains homogeneous for 15 minutes until the temperature reaches approximately 25 ° C.

3) Production and addition of potassium alkylhydroxybenzoate A method for producing potassium alkylhydroxybenzoate is described below.

A) Neutralization step:
Four-necked reactor while stirring 1200 g of alkylphenol derived from alkyl group from a mixture of C ₂₀ -C ₂₈ linear alpha olefin (manufactured by Chevron Phillips Chemical Company (CPC)) and 632 g of ethylhexanol under reduced pressure Put in.

The reaction mixture is heated from ambient temperature to 95 ° C. over 25 minutes at 10 ⁵ Pa (absolute pressure) and then 311.8 g of a 50% by weight aqueous potassium hydroxide solution are added. The mixture was then brought to a temperature of 195 ° C. over 3 hours 30 minutes. The purity of KOH is 86.4% by mass, water: 50% by mass, and the effective amount of KOH is: 311.8 × 0.5 × 0.864 = 13.4 g [CMR (KOH / alkylphenol) = 0. Corresponds to 9]. Continue heating until a reflux temperature of 210 ° C. is reached and maintain at that temperature for 2 hours.

Next, in order to distill the solvent, the temperature is lowered to 195 ° C. while reducing the vacuum to 4 × 10 ³ Pa. Maintain this temperature and pressure for 30 minutes while continuing to stir at 600 rpm. At the end of the distillation operation, 554.2 g of 100N 100N diluent oil with a viscosity of 37.8 ° C. was slowly added. When the temperature reaches 170 ° C., the decompression is stopped and nitrogen is purged while continuing the addition of diluent oil.

B) Carboxylation step:
The mixture obtained in the neutralization step described above is placed in a stainless steel reactor while stirring under reduced pressure. Next, carbon dioxide was introduced into the reactor at a temperature of 125 ° C. to 130 ° C. over 6 hours at a pressure of 3.5 × 10 ⁵ Pa. Potassium alkylhydroxybenzoate having C ₂₀ -C ₂₈ alkyl chain (alkyl salicylate), is recovered together with the unreacted alkylphenol and potassium alkyl phenate. 720 g of potassium C ₂₀ -C ₂₈ alkyl hydroxybenzoate is added to the reactor over 20 minutes.

4) Carbonation After 43.7 g of carbon dioxide (1) was introduced into the reactor at a temperature of 30 ° C. to 40 ° C. over 90 minutes, 260.7 g of xylene (2), 24.4 g of methanol (2) and water A lime slurry containing 25 g of calcium oxide (2) is added to the reactor.

  Next, 13.1 g of carbon dioxide (2) is introduced into the reactor at a temperature of 35 ° C. to 43 ° C. over 45 minutes.

5) Predistillation, centrifugation and final distillation The temperature of the mixture contained in the reactor is increased between 110 ° C. and 132 ° C., and 181.9 g of 600N diluent oil and 259 g of xylene are added in succession. Then another 181.9 g of 600N oil and 259 g of xylene (3) are again added one after another. The resulting mixture is centrifuged with an Alfa Laval Gyrotester (trade name, Alfa Laval Gyrotester) and placed at approximately 200 ° C. for 10 minutes under a partial vacuum of 4 × 10 ³ Pa to remove xylene. Heat to.

  Tables 1 and 2 below summarize the packing materials used in the production of medium overbased potassium carboxylates and medium overbased calcium alkylaryl sulfonates, and the analytical results obtained.

Table 1 ─────────────────────────────────────
Filling substances ─────────────────────────────────────
Linear alkylphenols CPC (C ₂₀ -C ₂₈ olefin derivatives) 100%
KOH / alkylphenol molar ratio 0.9
Lime (1) (g) 96.3
Lime (2) (g) 25
Methanol (1) (g) 92.5
Methanol (2) (g) 24.4
Xylene (1) (premixed) (g) 1042.4
Xylene (2) (g) 260.7
Xylene (3) (g) 259
CO ₂ (1) (g) 43.7
CO ₂ (2) (g) 13.1
Sulfonic acid (g) 120
Potassium alkyl salicylate (g) 720
Diluent oil (600N) (g) 181.9
Production amount (g) 1170.5
Total surfactant (after dialysis ¹ ) (g) 556
"Phenol" / total surfactant ² (wt / wt) 0.106
"Phenol" + "Hydroxybenzoic acid" / Total surfactant (wt / wt) 0.82
Total surfactant (mass%) 47.50
─────────────────────────────────────
TBN / total surfactant% 3.61
─────────────────────────────────────
1) To remove unreacted alkylphenol.
2) Carboxylate and sulfonate were measured in acid form.

Table 2 ─────────────────────────────────
Analysis ─────────────────────────────────
Linear alkylphenols CPC (C ₂₀ -C ₂₈ olefin derivatives) 100%
KOH / alkylphenol molar ratio 0.9
Overbasing stage analysis −
Potassium (mass%) 2.86
Calcium (mass%) 5.12
CaS% ASTM D3712 (mass%) 0.401
TBN ASTM D2896 (mgKOH / g) 171.5
Salicylic acid ¹ (mgKOH / g) 34.94
100 ° C. viscosity ASTM D445 (mm ² / s) 43.94
Appearance of oil (MAO23) 1/0
Color (ASTM D1500) 2.6DD
Crude sediment (ASTM D2273, volume%) 0.60
Final sediment (ASTM D2273, volume%) 0.02
────────────────────────────────
1) Indicated in mg KOH / g according to ASTM D2896.

(Antioxidant)
Examples of preferred antioxidants used in the lubricating oils of the present invention include diphenylamine type compounds, including but not limited to alkylated diphenylamine, phenyl-alpha-naphthylamine, and alkylated-alpha-naphthylamine. Is mentioned. Antioxidants that can be used also include esters of thiodicarboxylic acid, dithiocarbamates such as 15-methylenebis (dibutyldithiocarbamate), salts of dithiophosphoric acid, alkyl or aryl phosphate esters. Molybdenum compounds such as amine-molybdenum complex compounds and molybdenum dithiocarbamates can also be used as antioxidants, and hindered phenols such as 4,4′-methylene-bis (2,6-di-tert-butylphenol), 4,4′-bis (2,6-di-tert-butylphenol), 4,4′-bis (2-methyl-6-tert-butylphenol), 2,2′-methylene-bis (4-methyl-6) -T-butylphenol), 4,4'-butylidene-bis (3-methyl-6-t-butylphenol), 4,4'-isopropylidene-bis (2,6-di-t-butylphenol), 2,2 '-Methylene-bis (4-methyl-6-nonylphenol), 2,2'-isobutylidene-bis (4,6-dimethylphenol), 2,2'-5-methylene-bi (4-methyl-6-cyclohexylphenol), 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, 2,4-dimethyl-6-t -Butylphenol, 2,6-di-t-1-dimethylamino-p-cresol, 2,6-di-t-4- (N, N'-dimethylaminomethylphenol), 4,4'-thiobis (2 -Methyl-6-t-butylphenol), 2,2'-thiobis (4-methyl-6-t-butylphenol), bis (3-methyl-4-hydroxy-5-t-10-butylbenzyl) -sulfide, And bis (3,5-di-tert-butyl-4-hydroxybenzyl) can also be used. More preferred are diphenylamine type compounds, most preferred are alkylated diphenylamines.

(Dispersant)
A preferred dispersant that can be used in the lubricating oil composition of the present invention is an ashless dispersant. Examples of ashless dispersants are alkenyl succinimides and succinamides. These dispersants can be further modified, for example, by reaction with boron or ethylene carbonate. Ester ashless dispersants derived from long chain hydrocarbon-substituted carboxylic acids and hydroxy compounds can also be used. More preferred ashless dispersants are those derived from polyisobutenyl succinic anhydride, and most preferred are polyisobutenyl succinic anhydride derivative dispersants treated with ethylene carbonate. A number of dispersants are commercially available.

(Abrasion resistance additive)
Examples of antiwear additives include, but are not limited to, phosphate esters and thiophosphate esters and their salts, carbamates, esters, and molybdenum complexes. A preferred anti-wear additive contained in the lubricating oil composition of the present invention is a metal dialkyldithiophosphate. However, since the metal and phosphorus contribute to the lubricating oil, it can be said that it is advantageous to suppress the amount of this additive. Examples of metal dialkyldithiophosphates include zinc and molybdenum salts of dialkyldithiophosphates. The most preferred anti-wear additive used in the lubricating oil composition of the present invention is zinc dialkyldithiophosphate.

[Other additives]
In addition to the additives described above, the lubricating oil composition of the present invention may also contain other additives that are used to impart desired properties to the lubricating oil composition of the present invention. Therefore, the lubricating oil may contain one or more additives such as a viscosity index improver, a pour point depressant, a demulsifier, an extreme pressure agent, and an antifoaming agent. In the following, these additional additives are described in detail.

(Viscosity index improver)
Viscosity index improvers are added to lubricating oils to adjust viscosity changes due to temperature changes. Some examples of commercially available viscosity index improvers include olefin copolymers such as ethylene-propylene copolymers, styrene-isoprene copolymers, hydrated styrene-isoprene copolymers, polybutenes, polyisobutylenes, There are polymethacrylates, copolymers of vinyl pyrrolidone and methacrylate, and dispersion type viscosity index improvers.

(Extreme pressure agent)
Examples of extreme pressure agents that can be used in the lubricating oil composition of the present invention include alkaline earth metal borated extreme pressure agents and alkali metal borated extreme pressure agents. Extreme pressure agents containing molybdenum may also be used in the lubricating oil composition of the present invention as long as the molybdenum compound does not contain trinuclear molybdenum. Sulfurized olefin, zinc dialkyl-1-dithiophosphate (primary alkyl, secondary alkyl and aryl type), diphenyl sulfide, methyltrichlorostearate, chlorinated naphthalene, fluoroalkylpolysiloxane, lead naphthenate, neutralized or partial Neutralized phosphate esters, dithiophosphate esters, and sulfur-free phosphate esters. Preferred extreme pressure agents are those that do not contribute to the phosphorus content of the lubricating oil.

(Pour point depressant)
Polymethylmethacrylate is an example of a pour point depressant that can be used to add to the lubricating oil of the present invention.

(Anti-rust additive)
Anti-corrosive additives include nonionic polyoxyethylene surfactants such as polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene octyl stearyl Mention may be made of ethers, polyoxyethylene oleyl ethers, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol monooleate, and polyethylene glycol monooleate. Other compounds that can be used as rust inhibitors include stearic acid and other fatty acids, dicarboxylic acids, metal soaps, fatty acid amine salts, metal salts of heavy sulfonic acids, and partial carboxylic acid esters of polyhydric alcohols. , And phosphate esters. However, preferred rust inhibitors are those that do not contribute to the phosphorus or sulfur content of the lubricating oil.

(Corrosion inhibitor)
Corrosion inhibitors are included in lubricating oils to protect sensitive metal surfaces. Such corrosion inhibitors are generally used in very small amounts in the range of about 0.02% to about 1.0% by weight. Examples of corrosion inhibitors that can be used include sulfurized olefin corrosion inhibitors and co-sulfurized alkenyl ester / alpha olefin corrosion inhibitors. The corrosion inhibitor should not be a metal dithiophosphate, in particular zinc dialkyldithiophosphate, because the addition of this corrosion inhibitor will contribute to the zinc, phosphorus and sulfur content of the lubricating oil.

(Friction modifier)
Examples of the friction modifier used in the lubricating oil composition of the present invention include both ash-containing friction modifiers and ashless friction modifiers. Friction modifiers include, but are not limited to, fatty alcohols, fatty acids such as stearic acid, isostearic acid, oleic acid and other fatty acids, or salts and esters thereof, borated esters, amines, phosphoric acids. Mention may be made of esters, and di- and tri-hydrocarbon phosphate esters, hydrocarbon phosphite esters and phosphonate esters. The friction modifier may contain molybdenum as long as the molybdenum compound does not contain trinuclear molybdenum. Preferably, the friction modifier used in the lubricating oil composition of the present invention is an ashless friction modifier.

(Metal deactivator)
Metal deactivators that can be used in the lubricating oil composition of the present invention include, but are not limited to, disalicylidenepropylenediamine, triazole derivatives, mercaptobenzothiazole, thiadiazole derivatives, and mercaptobenz. Mention may be made of imidazole.

(Seal swelling agent)
The lubricating oil composition of the present invention may use seal swell agents, including but not limited to diesters such as di-2-ethylhexyl sebacate, dioctyl adipate and di-2-ethylhexyl phthalate, tridecyl Mention may be made of mineral oils containing aliphatic alcohols such as alcohols, and tris phosphites in combination with hydrocarbonyl-substituted phenols.

(Demulsifier)
An adduct of alkylphenol and ethylene oxide, polyoxyethylene alkyl ether, and polyoxyethylene sorbitan ester can be used in the lubricating oil composition of the present invention.

(Defoamer)
Antifoaming agents that can be used in the present invention are alkyl methacrylate polymers, dimethyl silicone polymers, and polysiloxane type antifoaming agents.

  In order to obtain the best overall results in view of imparting the desired properties to conventional lubricating oil compositions for lubricating diesel engines, gasoline engines and natural gas engines, lubricating oils are a class of additives described above. Each of the miscible additive combinations can be included in an effective amount.

  The various additive materials or classes of materials described herein are well-known materials that can be easily purchased commercially or produced by known methods or obvious modifications thereof. .

  Table 3 below shows the processing ratios of the additives that can be used in the lubricating oil of the present invention. All component amounts are stated as mass% of active additive.

Table 3 ─────────────────────────────────────
Component Range Preferred Range Most preferred
(Mass%) (mass%) Range (mass%)
─────────────────────────────────────
Detergent 0-10 0.5-8 1-6
Antioxidant 0-3.0 0.2-2.0 0.2-1.5
Dispersant 0-12 1-10 2-8
Abrasion resistance additive 0-5 0.1-3 0.2-2
Viscosity index improver 0-3 0.2-2 0.3-1
Extreme pressure agent 0-2.0 0-1.0 0.1-0.5
Pour point depressant 0-1.0 0.05-0.5 0.05-0.3
Rust prevention additive 0-1.0 0-0.75 0.05-0.5
Corrosion inhibitor 0-3.0 0.2-2.0 0.2-1.5
Friction modifier 0-1.0 0.05-0.75 0.1-0.5
Antifoam 0-3.0 0.2-2.0 0.2-1.5
─────────────────────────────────────

  The lubricating oil composition of the present invention was evaluated for its ability to reduce catalyst poisoning with formulations prepared as described in Example 1 and Table 3 below.

[Example 1]
Comparative Formulations AC and Test Formulation D contained an amine-containing antioxidant, an ethylene carbonate-treated succinimide dispersant, a phosphorus-containing antiwear additive, a viscosity index improver and an antifoaming agent. Comparative Formula A also contains medium overbased calcium sulfide phenate, Comparative Formula B contains overbased calcium alkyl aryl sulfonate, Comparative Formula C contains overbased magnesium alkyl aryl sulfonate, and the test Formulation D contained a mixture of medium overbased potassium monoalkylcarboxylate and overbased calcium alkylaryl sulfonate in a ratio of 3.5 to 1.0. Base oil was used to make each of Comparative Formulation AC and Test Formulation D 100%.

  In addition to the above other ingredients, a reduction in catalyst poisoning when using test formulation D comprising medium overbased potassium monoalkylcarboxylate and medium overbased calcium alkylaryl sulfonate is added to the other ingredients. And comparative formulations AC containing only calcium or magnesium phenate or alkylaryl sulfonate.

  Table 4 below details the comparative formulations AC and test formulation D. The amounts of the components of the lubricating oil formulation are listed in Table 4 in terms of mass% active additive.

Example 2 Catalyst poisoning The reduction in catalyst poisoning in the exhaust gas aftertreatment device was measured with test formulation B and compared with comparative formulation A as described below.

  Catalyst poisoning was measured using a Honda E5 generator set with a 0.3 liter, 2 cylinder, OHC engine. In order to promote catalyst aging, the catalyst core was made smaller than usual and the engine valve guide was removed. The catalyst core was placed far enough from the downflow to prevent sintering. After catalyst aging, the conversion efficiency of the core and the deposited additive metal were measured using a synthesis gas reactor.

  The gas reactor was operated in three different states: lean, rich and confused. The confused state most closely simulates the engine environment by alternating the gas mixture between lean and rich states. The experiment consisted of measuring the conversion efficiency of hydrocarbons, carbon monoxide and nitrogen oxides as a function of time and the temperature expressed as a predetermined temperature increase. The temperature increase was planned so that the warm-up operation of the catalytic converter could be simulated during the engine start-up process. The temperature was increased non-linearly from a baseline temperature of 150 ° C. to a maximum of 425 ° C. After reaching a certain temperature, the conversion rapidly increased when the catalyst “ignited”. The temperature at which 50% conversion (T50) is observed is taken as the measured value for ignition and catalyst poisoning. Thus, the lower T50, the more positive the conversion and the negative the catalyst poisoning.

  The data reported is the T50 at the end of the test. Table 5 below summarizes the results of the catalyst poisoning test.

Table 5 ──────────────────────────────────
Ingredient formulation
Comparative formulation Comparative formulation Comparative formulation Test formulation
A B C D
──────────────────────────────────
T50 314 ° C 306 ° C 310 ° C 273 ° C
──────────────────────────────────

  The results obtained in the catalyst poisoning tests summarized in Table 5 above were determined by measuring T50 as the temperature at which the catalyst “ignited” for Comparative Formulation AC and Test Formulation D. Indicates catalyst poisoning. The results show that the T50 for Comparative Formula A containing medium overbased calcium sulfide phenate, Comparative Formula B containing overbased calcium alkyl aryl sulfonate, and Comparative Formula C containing overbased magnesium alkyl aryl sulfonate were 314, respectively. C., 306.degree. C., and 310.degree. C., while the T50 measured for test formulation D containing a mixture of medium overbased potassium monoalkylcarboxylate and overbased calcium alkylaryl sulfonate was 273.degree. It is shown that. The data was observed in comparative formulations AC by adding a mixture of medium overbased potassium monoalkylcarboxylate and medium overbased calcium alkylaryl sulfonate to test formulation D containing twice the amount of phosphorus. The catalyst poisoning was reduced by 13.1, 10.8 and 11.9%, respectively, compared to the catalyst poisoning. The data show that adding a mixture of medium overbased potassium monoalkylcarboxylate and medium overbased calcium alkylaryl sulfonate to test formulation D results in wear inhibition and at the same time protects against catalyst poisoning. Seems to be.

  The results of the catalyst poisoning tests summarized in Table 5 above show that for test formulation B using a mixture of medium overbased potassium carboxylate and medium overbased calcium alkylaryl sulfonate, medium overbased potassium carboxy It did not contain a mixture of rate and medium overbased calcium alkyl aryl sulfonate, but revealed reduced catalyst poisoning compared to Comparative Formulation AC, which contained half the amount of phosphorus in the formulation. . It has been known in the art that phosphorus-containing additives in lubricating oils harm the catalyst. Therefore, the phosphorus content of test formulation D was twice as high as that of comparative formulations A-C, so the results obtained in the catalyst poisoning test could not be predicted. From prior knowledge, when using a lubricating oil formulation comprising a mixture of medium overbased potassium carboxylate and medium overbased calcium alkylaryl sulfonate, it was observed from the catalyst poisoning observed in the presence of phosphorus. Protection was a phenomenal result.

Claims (52)

A lubricating oil composition comprising the following ingredients:
(A) a major amount of oil of lubricating viscosity;
(B) a mixture of an overbased potassium detergent and an overbased calcium detergent;
(C) one or more antioxidants,
(D) one or more succinimide derivative dispersants, and (e) one or more antiwear additives,
However, the lubricating oil composition does not contain more than 0.12% by weight of phosphorus and the lubricating oil composition does not contain dialkylcarboxylates.   The ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition ranges from about 0.5: 1.0 to about 10.0: 1.0. Lubricating oil composition.   The ratio of the overbased potassium detergent to the overbased calcium detergent in the lubricating oil composition is in the range of about 1.0: 1.0 to about 7.5: 1.0. Lubricating oil composition.   The ratio of the overbased potassium detergent to the overbased calcium detergent in the lubricating oil composition is in the range of about 2.0: 1.0 to about 5.0: 1.0. Lubricating oil composition.   The lubricating oil composition of claim 4, wherein the ratio of the overbased potassium detergent to the overbased calcium detergent in the lubricating oil composition is 3.5: 1.0.   The lubricating oil composition of claim 1, wherein the concentration of potassium in the overbased potassium detergent is in the range of about 1.0% to about 10.0% by weight based on the total weight of the overbased potassium detergent. object.   The lubricating oil composition of claim 6, wherein the concentration of potassium in the overbased potassium detergent is in the range of about 1.5% to about 7.5% by weight, based on the total weight of the overbased potassium detergent. object.   The lubricating oil composition of claim 7, wherein the concentration of potassium in the overbased potassium detergent is in the range of about 2.0 wt% to about 5.0 wt% based on the total weight of the overbased potassium detergent. object.   The lubricating oil composition of claim 8, wherein the concentration of potassium in the overbased potassium detergent is in the range of about 2.5% to about 3.0% by weight, based on the total weight of the overbased potassium detergent. object.   The lubricating oil composition of claim 1, wherein the concentration of calcium in the overbased calcium detergent is in the range of about 1.0% to about 15.0% by weight, based on the total weight of the overbased calcium detergent. object.   11. The lubricating oil composition of claim 10, wherein the concentration of calcium in the overbased calcium detergent is in the range of about 2.0% to about 10.0% by weight based on the total weight of the overbased calcium detergent. object.   12. The lubricating oil composition of claim 11, wherein the concentration of calcium in the overbased calcium detergent is in the range of about 3.0% to about 7.5% by weight based on the total weight of the overbased calcium detergent. object.   The lubricating oil composition of claim 12, wherein the concentration of calcium in the overbased calcium detergent is in the range of about 4.0% to about 6.0% by weight based on the total weight of the overbased calcium detergent. object.   The lubricating oil composition of claim 1, wherein the phosphorus content is in the range of 0.03% to about 0.12% by weight based on the total weight of the lubricating oil composition.   The lubricating oil composition of claim 14, wherein the phosphorus content is in the range of 0.05 wt% to about 0.1 wt% based on the total weight of the lubricating oil composition.   The lubricating oil composition of claim 15, wherein the phosphorus content is in the range of 0.07 wt% to about 0.09 wt% based on the total weight of the lubricating oil composition. A lubricating oil composition comprising the following ingredients:
(A) a major amount of oil of lubricating viscosity;
(B) a mixture of an overbased potassium monoalkylcarboxylate and an overbased calcium alkylaryl sulfonate;
(C) an amine-containing antioxidant,
(D) an ethylene carbonate-treated succinimide dispersant, and (e) a phosphorus-containing antiwear additive,
However, the lubricating oil composition does not contain more than 0.12% by weight phosphorus and the lubricating oil composition does not contain a dialkylcarboxylate detergent.   18. The ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition is in the range of about 0.5: 1.0 to about 10.0: 1.0. Lubricating oil composition.   The ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition is in the range of about 1.0: 1.0 to about 7.5: 1.0. Lubricating oil composition.   20. The ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition is in the range of about 2.0: 1.0 to about 5.0: 1.0. Lubricating oil composition.   The lubricating oil composition of claim 20, wherein the ratio of the overbased potassium detergent to the overbased calcium detergent in the lubricating oil composition is 3.5: 1.0.   18. The lubricating oil composition of claim 17, wherein the concentration of potassium in the overbased potassium detergent is in the range of about 1.0% to about 10.0% by weight based on the total weight of the overbased potassium detergent. object.   The lubricating oil composition of claim 22, wherein the concentration of potassium in the overbased potassium detergent is in the range of about 1.5% to about 7.5% by weight, based on the total weight of the overbased potassium detergent. object.   24. The lubricating oil composition of claim 23, wherein the concentration of potassium in the overbased potassium detergent is in the range of about 2.0% to about 5.0% by weight based on the total weight of the overbased potassium detergent. object.   25. The lubricating oil composition of claim 24, wherein the concentration of potassium in the overbased potassium detergent is in the range of about 2.5% to about 3.0% by weight based on the total weight of the overbased potassium detergent. object.   18. The lubricating oil composition of claim 17, wherein the concentration of calcium in the overbased calcium detergent is in the range of about 1.0% to about 15.0% by weight based on the total weight of the overbased calcium detergent. object.   27. The lubricating oil composition of claim 26, wherein the concentration of calcium in the overbased calcium detergent is in the range of about 2.0% to about 10.0% by weight based on the total weight of the overbased calcium detergent. object.   28. The lubricating oil composition of claim 27, wherein the concentration of calcium in the overbased calcium detergent is in the range of about 3.0% to about 7.5% by weight based on the total weight of the overbased calcium detergent. object.   30. The lubricating oil composition of claim 28, wherein the concentration of calcium in the overbased calcium detergent is in the range of about 4.0% to about 6.0% by weight based on the total weight of the overbased calcium detergent. object.   The lubricating oil composition of claim 17, wherein the phosphorus content is in the range of 0.03% to about 0.12% by weight based on the total weight of the lubricating oil composition.   The lubricating oil composition of claim 30, wherein the phosphorus content is in the range of 0.05 wt% to about 0.1 wt% based on the total weight of the lubricating oil composition.   32. The lubricating oil composition of claim 31, wherein the phosphorus content is in the range of 0.07% to about 0.09% by weight based on the total weight of the lubricating oil composition.   The lubricating oil composition of claim 17, wherein the phosphorus-containing antiwear additive is a metal dialkyldithiophosphate.   34. A lubricating oil composition according to claim 33, wherein the metal of the metal dialkyldithiophosphate is zinc. Lubricating oil concentrate containing the following ingredients:
(A) an oil having a lubricating viscosity of about 10% to about 90% by weight;
(B) a mixture of an overbased potassium detergent and an overbased calcium detergent;
(C) one or more antioxidants,
(D) one or more succinimide derivative dispersants, and (e) one or more antiwear additives,
However, the lubricant concentrate does not contain more than 0.12% phosphorus and the lubricant concentrate does not contain dialkylcarboxylates.   36. The lubricating oil concentrate according to claim 35, wherein the phosphorus-containing antiwear additive is zinc dialkyldithione phosphate. Lubricating oil concentrate containing the following ingredients:
(A) an oil of lubricating viscosity of about 10% to about 90% by weight, based on the total weight of the lubricating oil concentrate;
(B) a mixture of an overbased potassium monoalkylcarboxylate and an overbased calcium alkylaryl sulfonate;
(C) an amine-containing antioxidant,
(D) an ethylene carbonate-treated succinimide dispersant, and (e) a phosphorus-containing antiwear additive,
However, the lubricant concentrate does not contain more than 0.12% phosphorus and the lubricant concentrate does not contain a dialkylcarboxylate detergent.   38. The ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition is in the range of about 0.5: 1.0 to about 10.0: 1.0. The lubricating oil concentrate as described.   The ratio of the overbased potassium detergent to the overbased calcium detergent in the lubricating oil composition is in the range of about 1.0: 1.0 to about 7.5: 1.0. The lubricating oil concentrate as described.   40. The ratio of the overbased potassium detergent to the overbased calcium detergent in the lubricating oil composition is in the range of about 2.0: 1.0 to about 5.0: 1.0. The lubricating oil concentrate as described.   41. The lubricating oil concentrate of claim 40, wherein the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition is 3.5: 1.0.   38. The lubricating oil concentrate of claim 37, wherein the phosphorus-containing antiwear additive is zinc dialkyldithione phosphate. A method for reducing catalyst poisoning in an exhaust gas aftertreatment device of an internal combustion engine, the method comprising operating the internal combustion engine using a lubricating oil composition comprising the following components:
(A) an oil having a lubricating viscosity of about 10% to about 90% by weight;
(B) a mixture of an overbased potassium detergent and an overbased calcium detergent;
(C) one or more antioxidants,
(D) one or more succinimide derivative dispersants, and (e) one or more antiwear additives,
However, the lubricating oil composition does not contain more than 0.12% by weight of phosphorus and the lubricating oil composition does not contain dialkylcarboxylates.   44. The method of claim 43, wherein the internal combustion engine is a diesel engine, a gasoline engine, and a natural gas engine.   44. The method of claim 43, wherein the phosphorus-containing antiwear additive is zinc dialkyldithione phosphate. A method for reducing catalyst poisoning in an exhaust gas aftertreatment device of an internal combustion engine, the method comprising operating the internal combustion engine using a lubricating oil composition comprising the following components:
(A) a major amount of oil of lubricating viscosity;
(B) a mixture of overbased potassium monoalkylcarboxylate and overbased calcium alkylaryl sulfonate;
(C) amine-containing antioxidant and phenolic antioxidant,
(D) an ethylene carbonate-treated succinimide dispersant, and (e) a phosphorus-containing antiwear additive,
However, the lubricating oil composition does not contain more than 0.12% by weight phosphorus and the lubricating oil composition does not contain a dialkylcarboxylate detergent.   47. The ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition is in the range of about 0.5: 1.0 to about 10.0: 1.0. The method described.   48. The ratio of the overbased potassium detergent to the overbased calcium detergent in the lubricating oil composition is in the range of about 1.0: 1.0 to about 7.5: 1.0. The method described.   49. The ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition is in the range of about 2.0: 1.0 to about 5.0: 1.0. The method described.   50. The method of claim 49, wherein the ratio of overbased potassium detergent to overbased calcium detergent in the lubricating oil composition is 3.5: 1.0.   47. The method of claim 46, wherein the internal combustion engine is a diesel engine, a gasoline engine, and a natural gas engine.   47. The method of claim 46, wherein the phosphorus-containing antiwear additive is a zinc dialkyldithione phosphate.