KR20120026007A - Lubricating oil composition - Google Patents

Abstract

PURPOSE: A lubricant oil composition is provided to offer high temperature detergency and excellent abrasion resistance to engines with minimum influence on an exhaust gas purifying device for discharging an oxidation catalyst. CONSTITUTION: A lubricant oil composition contains an ashless dispersing agent dissolved in base oil containing less than 0.1wt% of sulfur, a calcium alkylsalicylate detergent, a zinc phosphate anti-abrasive agent, and an oxidation inhibitor. The ashless dispersing agent is selected from the group consisting of alkenyl succinimide, alkyl succinimide, or their derivative. The lubricant oil composition additionally contains 0.1-1.1wt% of sulfated ash, 0.01-0.12wt% of phosphor, 0.01-0.5wt% of sulfur, and less than 150ppm of chlorine.

Description

Lubricating Oil Composition

The present invention relates to a lubricating oil composition which can advantageously be used for the lubrication of internal combustion engines operating on land such as diesel engines, gasoline engines or gas engines. More specifically, the present invention has a low sulphide ash content, a low phosphorus content and a low sulfur content, exhibits excellent high temperature cleaning power and anti-wear performance, and is used in the combustion of soot, fuels and lubricants contained in particulate filters or exhaust gases. By reducing the adverse impacts on exhaust gas purification devices such as oxidation catalysts mounted on automobiles for oxidation, the lubricating oil composition can meet the stringent emission requirements recently adopted, and more likely to be adopted in the future. A lubricating oil composition for an internal combustion engine that can also meet stringent exhaust gas requirements.

In particular, the invention relates to automobiles operating with hydrocarbon fuel oils having sulfur contents of up to about 0.005% by weight, in particular up to about 0.001% by weight, in particular with diesel engines equipped with exhaust gas purification devices such as particulate filters and oxidation catalysts. It provides an environmentally friendly lubricant composition for an internal combustion engine that can be advantageously used with automobiles.

Recently, diesel-powered vehicles operating on land have become very important in reducing environmental pollution caused by particulate matter and emissions components such as NOx. It is known that emissions can be reduced by mounting exhaust gas-cleaning devices such as particulate filters and oxidation catalysts mounted on motor vehicles. However, although the soot adsorbed on the filter is removed through oxidation and combustion in the exhaust gas scrubber, the metal oxide produced by the combustion of a known lubricating oil composition having a high sulfur content, a high phosphorus content and a high sulfur content, The particulate filter is blocked by sulfurized ash and carboxylic acids.

In addition, there is a need to reduce the sulfur content in fuel oil because sulfur in the fuel oil produces undesirable substances in the exhaust gas such as sulfuric acid and sulfates which adversely affect the oxidation catalyst. For example, the sulfur content of diesel fuel oil for automobiles with diesel engines is reduced to less than about 0.005% by weight to less than about 0.001% by weight. When the sulfur content in the fuel oil is reduced, the content of the metal-containing detergent provided to neutralize sulfuric acid and the like in the lubricating oil composition can be reduced. It is known that some of the lubricating oil composition is burned in the engine and incorporated into the exhaust gas. Therefore, the lower the metal content and the sulfur content in the lubricating oil composition, the better. It is also desirable to reduce the phosphorus content in the lubricating oil composition to prevent deterioration of the catalyst. In addition, it is also desirable to lower the chlorine content of the lubricating oil composition to prevent dioxine contamination of the off-gas.

To date, diesel engines used onshore for motor vehicles, hoisting machines and electric generators generally have fuel oils (light oil or heavy oil) having sulfur content of at least about 0.005% by weight and sulfuric ash ash of about 1.3 to 2% by weight. It was operated using a lubricating oil composition having a content, a sulfur content of 0.3 to 0.7 wt%, and a phosphorus content of about 0.1 to 0.13 wt%.

JPA 2002-53888 (corresponding patent application of US 2002/0019320 A1) discloses low sulphide ash content, low phosphorus content, low sulfur content and low chlorine, which is available for diesel engines operating using fuel oils with low sulfur content. Lubricant compositions are disclosed that meet recent requirements for content requirements. More specifically, JPA 2002-53888 discloses a lubricating oil composition having a sulfur content of 0.01 to 0.3% by weight and a phosphorus content of 0.01 to 0.1% by weight and providing 0.1 to 1% by weight of sulfided ash. Lube oil composition

a) mineral base oil having a major amount of sulfur, at least 0.1% by weight, preferably at least 0.03% by weight;

b) ashless dispersant comprising alkenyl- or alkyl-succinimide or derivatives thereof, 0.01 to 0.3% by weight, based on the nitrogen atom content;

c) a non-sulfated alkali metal or alkaline earth metal salt of alkylsalicylic acid having a TBN of 10 to 350 mg KOH / g and an unsulfated alkali metal or alkaline earth metal of an alkylphenol derivative having a Mannich base structure. Metal-containing cleaners comprising organic acid metal salts, 0.1 to 1 percent by weight, based on the content of sulfurized ash;

d) zinc dialkyldithiophosphate, 0.01-0.1 wt% based on phosphorus content; And

e) an antioxidant selected from the group consisting of phenol compounds and amine compounds, 0.01 to 5% by weight,

Here, the amount is calculated based on the amount of the lubricating oil composition.

It is further described that preferred metal containing detergents are alkali metal salts or alkaline earth metal salts of unsulfated alkylsalicylic acid having an average carbon atom of about 8 to 30 carbon atoms.

In the recently set JASO M 355: 2008 (for lubricants for automotive diesel engines), the lubricant according to DH-2-08 for trucks and buses with aftertreatment to meet emissions regulations is 1.0 ± 0.1% by weight. It is stated that it is mandatory to have a sulfurized ash content, a sulfur content of less than 0.12% by weight, a sulfur content of less than 0.5% by weight, and a chlorine content of less than 150 ppm.

The object of the present invention is to meet the requirements of the aforementioned JASM M 355: 2008 and exhibit improved high temperature cleaning power of at least 300 ° C. compared to the lubricating oil compositions disclosed in JPA 2002-53888 as mentioned above, so as to be expected to operate under elevated temperatures. It is to provide a lubricating oil composition for an internal combustion engine that fully meets the harsher engine operating conditions.

The present invention is advantageous for the lubrication of internal combustion engines operating on land, such as diesel engines, gasoline engines or gas engines, which have a low sulphide ash content, a low phosphorus content and a low sulfur content and which exhibit good hot cleaning and anti-wear performance. It is an object to provide a lubricating oil composition which can be used.

Summary of the Invention

The present inventors have studied the lubricating oil compositions described in JPA 2002-53888 to improve the high temperature detergency achieved by the disclosed lubricating oil compositions, and have been applied to non-sulfated alkaline earth metal alkylsalicylates having alkyl groups having about 8 to 30 average carbon atoms. It has been found that improved high temperature cleaning power of at least 300 ° C. is achieved by lubricating oil compositions in which a non-sulphired calcium alkylsalicylate detergent having an alkyl group having from 14 to 18 carbon atoms is used. The lubricating oil composition thus prepared exhibits satisfactory good anti-wear performance and low viscosity at satisfactory low temperature so that the lubricating oil composition can be advantageously used in cold fat. The present invention has been invented based on this finding by the inventors.

Accordingly, the present invention relates to lubricating oil compositions for internal combustion engine lubricating oils operating with a fuel oil having a sulfur content of less than 0.005% by weight, in particular less than 0.001% by weight, with less than 0.1% by weight, preferably less than 0.03% by weight of sulfur. The following components a) to d) dissolved or dispersed in a base oil having a content, containing from 0.1 to 1.1 wt% of ash sulfide, from 0.01 to 0.12 wt% of phosphorus, from 0.01 to 0.5 wt% of sulfur and from 150 A lubricating oil composition for lubricating internal combustion engines having a chlorine content of less than ppm:

a) 0.01 to 0.3% by weight ashless dispersant, based on nitrogen content, selected from the group consisting of alkenyl succinimides, alkyl succinimides, or derivatives thereof;

b) having a sulfur content of less than 3% by weight and a total number of bases of 10 to 350 mg KOH / g, wherein the lubricating oil composition is 0.2 to 7% by weight, preferably 0.5 to 5% by weight, more preferably 1.0 to the weight of the composition 0.1 to 1 weight percent based on sulfidated ash content, comprising a non-sulfurized calcium alkylsalicylate detergent comprising an organic acid calcium salt and having an alkyl group having 14 to 18 carbon atoms under conditions comprising from about 3 wt% to an organic acid calcium salt % Calcium alkylsalicylate cleaner;

c) 0.01 to 0.12% by weight zinc phosphate antiwear agent, based on phosphorus content, selected from the group consisting of zinc dialkyldithiophosphate and zinc dihydrocarbylphosphate; And

d) 0.01 to 5% by weight of an inhibitor of oxidation, selected from the group consisting of antioxidant phenol compounds and antioxidant amine compounds,

Here, the sulfidated ash content, phosphorus content, sulfur content and weight% given in a) to d) are values based on the amount of lubricating oil composition.

The lubricating oil composition of the present invention has a low sulphide ash content, a low phosphorus content and a low sulfur content similar to the lubricating oil composition disclosed in JPA 2002-53888 mentioned above, but exhibits improved high temperature detergency at temperatures above 300 ° C. In addition, the lubricating oil compositions of the present invention exhibit satisfactory good anti-wear performance. In addition, the lubricating oil composition of the present invention exhibits a satisfactory low viscosity at low temperatures so that the lubricating oil composition can be advantageously used even in cold fats.

Therefore, the lubricating oil compositions of the present invention use hydrocarbon fuel oils having sulfur content of less than about 0.005% by weight, in particular less than 0.001% by weight, in particular mounted on motor vehicles equipped with exhaust gas purification devices such as particulate filters and oxidation catalysts. It is thus particularly advantageously used to lubricate diesel engines operating in cold climates.

Preferred embodiments of the invention are described below.

The calcium alkylsalicylate detergent of component (b) has a total base number in the range of 30 to 300 mg KOH / g.

(2) Unsulfated calcium alkylsalicylate detergents having alkyl groups having 14 to 18 carbon atoms have a total base number in the range of 100 to 250 mg KOH / g.

(3) The ashless dispersant of component a) comprises succinimide or derivative thereof obtained by the reaction of polybutenyl succinic anhydride with a polyamine, wherein polybutenyl succinic anhydride is used to convert polybutene and maleic anhydride to chlorine or chlorine. Obtained by thermal reaction in the absence of a containing compound.

(4) The lubricating oil composition contains 0.01 to 5% by weight of molybdenum-containing compound.

(5) The lubricating oil composition has a total base number in the range of 1 to 17 mg KOH / g, in particular 2 to 13 mg KOH / g.

(6) The lubricating oil composition is a multigrade engine oil comprising a viscosity index improver and is a 0W5, 0W10, 0W15, 0W20, 0W30, 5W20, 5W30, 10W20, or 10W30 oil.

(7) The lubricating oil composition is used for lubricating diesel engines operated with fuel oils having a sulfur content of less than 0.005% by weight, in particular less than 0.001% by weight, and mounted in land vehicles.

The present invention further provides a method of operating a diesel engine mounted on a land vehicle using fuel oil having a sulfur content of less than 0.005% by weight, in particular less than 0.001% by weight.

Base oil

Base oils usable for lubricating lubricating oil compositions are generally mineral oils or synthetic oils having a dynamic viscosity of 2 to 50 mm ² / s at 100 ° C., with a sulfur content of less than 0.1% by weight, preferably less than 0.03% by weight. More preferably less than 0.005% by weight.

Mineral oils can be prepared by treating lubricating oil grade distillates by solvent purification and / or hydrotreating or hydrocracking. Preferably, super-hydrogenating base oils are used, such as base oils having a viscosity index in the range from 100 to 150, aromatic contents up to 5% by weight, and nitrogen and sulfur contents up to 55 ppm. Particularly preferred are high viscosity index base oils having a viscosity index of 140-160 obtainable by hydrogenation and isomerization of slack wax or GTL wax.

Synthetic oils include poly-α-olefins, ie, polymers of α-oliphenes having 3-12 carbon atoms; Esters of alcohols having 4 to 18 carbon atoms and dibasic acids such as sebacic acid, azelaic acid or adipic acid, for example dioctyl sebacate Phosphorus dialkyl esters; Polyol esters of monobasic acids having 3-18 carbon atoms with 1-tri-methylpropane or pentaerythritol; Or alkylbenzenes having alkyl groups having 9-40 carbon atoms. Synthetic oils are advantageously usable because they have almost no sulfur content, have high oxidative stability and high thermal stability at high temperatures, and further produce small amounts of residual hydrocarbonaceous material and soot.

Mineral base oils and synthetic base oils may be used singly. However, a combination of two or more mineral base oils and a combination of two or more synthetic base oils may also be used. In addition, mineral base oils and synthetic base oils may optionally be used in combination in determined ratios.

Other Lubricant Additives

Ashless dispersants used as component b) in the lubricating oil compositions of the present invention are alkenylsuccinimides, alkylsuccinimides or derivatives thereof, wherein the alkenyl groups and alkyl groups may be derived from polyolefins. Ashless dispersants are included in the lubricating oil composition at 0.01 to 0.3 weight percent based on the nitrogen content. Percents are given per weight of lubricating oil composition. Representative succinimides can be obtained by reaction between succinic anhydrides having substituents of high molecular weight alkenyl or alkyl and polyalkylene polyamines having an average nitrogen atom number of 4 to 10, preferably 5 to 7. High molecular weight alkenyl or alkyl is preferably derived from polybutene having an average molecular weight of about 900 to 3,000.

In the preparation of polybutenyl succinic anhydride by reaction of polybutene with maleic anhydride, chlorination procedures are generally used. However, the chlorination procedure leaves residual chlorine in the product, and thus the finally produced succinimide inevitably contains a large amount (eg about 2,000 to 3,000 ppm) of immobilized chlorine. In contrast, thermal reactions without chlorine provide the final product with an extremely low chlorine content (eg 0-30 ppm). Therefore, succinimides derived from polyisobutenyl succinimides obtained by thermal reaction can be advantageously used to construct lubricating oil compositions having a low chlorine content such as 0 to 30 ppm by weight. Succinimide can be worked up with boric acid, boron-containing compounds, alcohols, aldehydes, ketones, alkylphenols, cyclic carbonates or organic acids. Preferred are borate alkenyl- (or alkyl-) succinimides obtained by working up with boric acid or boron containing compounds and exhibiting high thermal stability and high oxidative stability.

Alkenyl- or alkyl-succinimides or derivatives thereof are essentially included in the lubricating oil composition. However, other ashless dispersants such as alkenyl-benzyl compounds or alkenylsuccinic esters may also be used in combination with alkenyl- or alkyl-succinimides or derivatives thereof.

The calcium alkylsalicylate detergent of component b) which is essentially included in the lubricating oil composition of the present invention comprises 0.2 to 7% by weight, preferably 0.5 to 5% by weight, more preferably 1.0 to 3% by weight, including the organic acid calcium salt. It provides a lubricating oil composition comprising a calcium salt of an organic acid in the amount of, and comprises a non-sulfurized calcium alkylsalicylate detergent having an alkyl group having 14 to 18 carbon atoms. In the present invention, "non-sulfurized calcium alkylsalicylate detergent having an alkyl group having 14 to 18 carbon atoms" refers to an unsulfurized calcium alkylsalicylate detergent having an alkyl group having at least 90 mol% of an alkyl group having 14 to 18 carbon atoms. Used to mean.

In the lubricating oil composition, an unsulphated calcium alkylsalicylate detergent comprising 20 to 28 carbon atoms may be used in combination with an unsulfurized calcium alkylsalicylate detergent having an alkyl group having 14 to 18 carbon atoms. "Unsulfated calcium alkylsalicylate detergent comprising 20 to 28 carbon atoms" is used to mean an unsulfated calcium alkylsalicylate detergent having an alkyl group having at least 90 mol% of an alkyl group having from 20 to 28 carbon atoms. .

Unsulfated calcium alkylsalicylate detergents are preferably calcium alkylsalicylates prepared from alkyl phenols (prepared from olefins with preferred carbon atoms and phenols) via the Kolbe-Schmitt reaction. In general, overbased calcium salicylate obtained through a carbonization process using slaked lime and carbon dioxide for overbasing is used as a calcium salicylate detergent.

Alternatively, the calcium alkylsalicylate can be prepared directly by carbonizing the alkylphenol calcium salt obtained by direct neutralization.

Metal-containing detergents may include alkali or alkaline earth metal salts of small amounts of organic acids or phenol derivatives with carbon-nitrogen bonds. Generally, the metal containing detergent may have an increased number of bases by the attachment of the amine compound through the reaction, so that the base number derived by the basic nitrogen atom of the amine compound may contribute to the increase in the base number of the cleaner. Therefore, a metal containing detergent having a low sulfurized ash but having a high base number can be obtained. For example, various compounds may be mentioned, such as metal salts of aminocarboxylic acids. In particular, unsulfated alkylphenates (alkaline metal salts or alkaline earth metal salts) having a Mannich base structure can be mentioned. Such compounds can be prepared from alkylphenols, formaldehyde, and amines or aminated compounds through the Mannich reaction, which aminoethylates the phenol ring and eventually neutralizes the reaction product with a base such as calcium hydroxide.

In addition to the metal-containing detergents described above so far, small amounts of sulfonates such as alkali metal salts or alkaline earth metal salts of petroleum sulfonic acid, alkylbenzenesulfonic acid or alkyltoluene sulfonic acid can be used in combination with alkylsalicylate detergents.

Sulphide phenates that have been used for known diesel engine oils are alkali metal salts or alkaline earth metal salts of sulfided alkylphenols. In general, calcium salts and magnesium salts are used. Sulphide phenates exhibit high temperature stability but generally have a high sulfur content of about 3% by weight or more generated by the sulfidation reaction. In the present invention, small amounts of sulfide phenates can be used in combination with alkylsalicylate detergents.

In the lubricating oil composition of the present invention, the organic acid calcium salts contained in such cleaning agents are mixed so as to be 0.2 to 7% by weight, preferably 0.5 to 5% by weight, more preferably 1.0 to 3% by weight, based on the weight of the lubricating oil composition. Two calcium alkylsalicylate detergents may be combined in combination under conditions to provide a lubricating oil composition comprising an organic acid calcium salt in an amount. The amount of the organic acid calcium salt can be adjusted by adjusting the content of the organic acid calcium salt in the detergent and / or by controlling the amount of the detergent to be mixed into the lubricating oil composition.

Calcium alkylsalicylate detergents are used for the preparation of organic acid calcium salts (generally called "soap content") and aggregated basic inorganic salt particles (generally calcium carbonate particles) surrounding organic calcium salts dispersed in an oily medium (generally about 25 to It is known that it is an oily dispersant) in an amount of 55% by weight. The content of the organic acid calcium salt in the lubricating oil composition is important for maintaining high temperature cleaning power (the ability to keep the inside of the engine running at high temperatures clean) at high levels.

The zinc phosphate antiwear agent of component c) is selected from the group consisting of zinc dialkyl-dithiophosphate and zinc dihydro-carbyl-phosphate. Such zinc phosphate anti-wear agents are well known, and their preparation methods and properties are also well known. Zinc phosphate antiwear agents are used in amounts of 0.01 to 0.12 weight percent based on phosphorus content. However, preferred amounts for reducing the phosphorus content and sulfur content in the lubricating oil composition range from 0.01 to 0.06.

The zinc dialkyldithiophosphate preferably has an alkyl group having 3 to 18 carbon atoms, or an alkylaryl group having an alkyl group having 3 to 18 carbon atoms. Mixtures of primary alcohols having 3 to 18 carbon atoms or alkyl alcohols having 3 to 18 carbon atoms and secondary alcohols having 3 to 18 carbon atoms (both primary and secondary alcohols are excellent Particular preference is given to zinc dialkyldithiophosphates having an alkyl group mixture derived from which exhibit wear performance). Zinc dialkyldithiophosphates derived from primary alcohols exhibit high temperature stability. Such zinc dithiophosphates can be used alone but in combinations which mainly include those derived from secondary alcohols and those derived from primary alcohols.

The lubricating oil composition of the present invention further comprises an antioxidant phenol compound and / or an antioxidant amine compound in an amount of 0.01 to 5% by weight, preferably 0.1 to 3% by weight. In general, lubricating oil compositions having a low sulphide ash content, a low phosphorus content and a low sulfur content comprise reduced amounts of metal containing detergents and zinc dithiophosphates, thereby exhibiting a decrease in high temperature detergency, oxidation stability and abrasion resistance. In order to improve this reduction it is necessary to include component d) in the lubricating oil composition. Component d) is preferably a diarylamine antioxidant and / or a hindered phenol antioxidant. Inclusion of such an antioxidant is effective in improving high temperature cleaning power. In one aspect, diarylamine antioxidants exhibiting base water derived from the nitrogen contained are preferred. In another aspect, an obstacle phenol antioxidant is preferable because it effectively inhibits oxidation caused by NOx.

Examples of hindered phenol antioxidants include 2,6-di-t-butyl-p-cresol, 4,4'-methylenebis (2,6-di-t-butylphenol), 4,4'-methylene Bis (6-t-butylphenol-o-cresol), 4,4'-isopropylidenebis (2,6-di-t-butylphenol), 4,4'-bis (2,6-di-t -Butylphenol), 2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'-thiobis (2-methyl-6-t-butylphenol), 2,2'- Thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate and octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate.

Examples of the diarylamine antioxidant include alkyldiphenylamines of mixed alkyl groups having 4 to 9 carbon atoms, p, p'-dioctyldiphenylamine, phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, Alkylated alpha-naphthylamine and alkylated phenyl-alpha-naphthylamine.

Each of the hindered phenol antioxidants and diarylamine antioxidants may be applied alone or in combination. Optionally other oil-soluble antioxidants may be used in combination with the antioxidants described above.

The lubricating oil composition of the present invention may further comprise multifunctional additives such as up to 5% by weight, in particular up to 0.01 to 5% by weight of hydrated alkali metal borate and / or molybdenum containing compounds. Most of these compounds have sulfur content and sulfur content. Therefore, the amount can be adjusted in consideration of the sulfurized ash content and sulfur content of the resultant lubricating oil composition.

Molybdenum-containing compounds are provided primarily as friction modifiers, antioxidants and anti-wear agents in lubricating oil compositions and additionally to improve high temperature cleansing power. The molybdenum containing compound is preferably included in the lubricating oil composition in an amount of 10 to 2,500 ppm based on the molybdenum metal content. Examples of molybdenum containing compounds include sulfur-containing succinimide-molybdenum complexes, oxymolybdenum dithiocarbamate sulfides, oxymolybdenum dithiophosphates, amine-molybdenum complexes, oxymolybdenum diethylateamides and oxymolybdenum monoglycerides do. In particular, succinimide-molybdenum complexes are effective in providing improved high temperature cleaning power.

Hydrated alkali metal borate is effective in providing the lubricating oil composition with improved hot cleaning power and increased base number. Hydrated alkali metal borate salts can be prepared by the procedures described in US Pat. Nos. 3,929,650 and 4,089,790. Carbonized neutral alkali or alkaline earth metal sulfonates in the presence of alkali metal hydroxides to provide overbased sulfonates and dispersions of fine alkali metal borate salts which can be prepared by reaction of overbased sulfonates with boric acid. desirable. It is preferred that ashless dispersants such as succinimide in the carbonation reaction are present in the reaction mixture. The alkali metal is preferably potassium or sodium. More specifically, the average internal diameter dispersed in the neutral calcium sulfonate and succinimide detergent mixture is about 0.3 or less and the structure KB ₃ O ₅ Particles of the product with H ₂ O can be mentioned. Considering its resistance to water, potassium can be replaced by sodium.

The lubricating oil composition of the present invention preferably comprises 20% by weight or less of the viscosity index improver, more preferably 1 to 20% by weight. Examples of viscosity index improvers include polymers such as polyalkylmethacrylates, ethylene-polyethylene copolymers, styrene-butadiene copolymers and polyisoprene. Dispersant Type Viscosity Index Enhancers or Multifunctional Viscosity Index Enhancers are obtained by linking dispersible groups to viscosity index enhancing polymers. Viscosity index improvers may be used alone or in combination.

The lubricating oil composition of the present invention additionally includes various coadditives. Examples of coadditives include zinc dithiocarbamate, methylenebis (dibutyldithiocarbamate), oil-soluble copper compounds, sulfur compounds (such as vulcanized olefins, vulcanized esters or polysulfides), phosphate esters, Phosphite esters, and organoamide compounds (eg oleylamide) and may be provided as antioxidants or anti-wear agents. Additionally, benzotriazole compounds and thiadiazole compounds provided as metalinactivaters can be mixed. In addition, polyoxyalkylene type nonionic surfactants such as polyoxyethylene alkylphenyl esters or copolymers of ethylene oxide and propyleneoxite are provided as rust inhibitors or antiemulsifiers. In addition, various amines, amides, amine salts or derivatives thereof or fatty acid esters of polyhydric alcohols or derivatives thereof that can be provided as friction modifiers can be mixed. Various compounds may be mixed that can serve as foam inhibitors or pour point depressants. Such coadditives are preferably mixed in the lubricating oil composition in an amount of up to 3% by weight, more preferably in an amount of 0.01 to 3% by weight.

Example

The invention is further described by the following non-limiting examples.

(1) Preparation of Lubricant Composition

A lubricating oil composition for the performance evaluation of a lubricating oil composition is prepared from the base oils and additives described below to provide a lubricating oil composition containing not less than 1.0% by weight of sulphide content, 0.09% by weight phosphorus, 0.2% by weight sulfur and 5 ppm of chlorine content. . A viscosity index improver is added to this lubricating oil composition to have a viscosity grade (SAE viscosity grade) of 5W30.

(2) base oils and additives

1) Base oil (mixture of the following base oil A and base oil B having a volume ratio of 35:65)

Base oil A: Super-hydrogenated base oil (dynamic viscosity at 100 ° C: 4.0 mm ² / s, viscosity index 123, sulfur content: 0.001% by weight or less)

Base oil B: Super-hydrogenated base oil (dynamic viscosity at 100 ° C: 6.5 mm ² / s, viscosity index 132, sulfur content: 0.001% by weight or less)

2) additive

Dispersant A: Ethylene carbonate post-treatment succinimide dispersant (nitrogen content: 0.85 wt%, chlorine content: 30 wt ppm) was prepared according to the method described in Example 17 of JP 7-150166 A. Reacting polybutene and maleic anhydride with an average molecular weight of about 2200 under thermal reaction conditions; The reaction product was reacted with a polyalkylenepolyamine having an average number of nitrogen molecules of 6.5 (per molecule) to produce a bis-type succinimide and the succinimide was treated with ethylene carbonate: 0.0085% by weight (Amount relative to nitrogen content).

Dispersant B: Boron-containing succinimide dispersant (nitrogen content: 1.5% by weight. Boron content: 0.5% by weight, chlorine content: 5 ppm by weight or less) was prepared according to the method described in Example 8 of JP 7-150166 A. Reacting polybutene and maleic anhydride having an average molecular weight of about 1300 under thermal reaction conditions; The reaction product was reacted with a polyalkylenepolyamine having an average number of nitrogen molecules of 6.5 (per molecule) to produce bis succinimide and the succinimide was treated with boric acid: 0.06% by weight (amount to nitrogen content).

Calcium Alkylsalicylate Dispersant (described below in Examples 1 to 4 and Comparative Example 1): 0.82 wt% (amount relative to sulfidated ash content)

ZnDTP: zinc dialkyldithiophosphate (derived from secondary alcohols having 3 to 8 carbon atoms; phosphorus: 7.2% by weight, zinc: 7.85% by weight, sulfur: 14.4% by weight): 0.09% by weight (amount to phosphorus content) )

Antioxidant A: Amine compound (dialkyl diphenylamine (alkyl: mixture of C ₄ alkyl and C ₈ alkyl), nitrogen: 4.6 wt%, TBN: 180 mg KOH / g): 0.7 wt%

Antioxidant B: Phenolic compound (octyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate): 0.7 wt%

Molybdenum-containing compound: Oxymolybdenum sulfide-succinimide complex (molybdenum: 5.4 wt%, sulfur: 3.7 wt%, TBN: 45 mg KOH / g): 0.85 wt%

Viscosity index improver: non-dispersant ethylene-propylene copolymer, paratone 8057)

Example  One

Lubricant composition (TBN: 9.6 mg KOH / g, organic acid calcium salt content: 1.5 wt%) was prepared using the following calcium alkylsalicylate dispersant:

Unsulfated calcium alkyl salicylate dispersant of alkyl group having 14 to 18 carbon atoms (TBN: 220 mg KOH / g, petroleum medium content: about 30% by weight, organic acid calcium salt content: 49% by weight)

Example  2

Lubricant composition (TBN: 9.6 mg KOH / g, organic acid calcium salt content: 1.5 wt%) was prepared using the following calcium alkylsalicylate dispersant:

Unsulfated calcium alkylsalicylate dispersant of an alkyl group having 14 to 18 carbon atoms (TBN: 225 mg KOH / g, petroleum medium content: at most about 30% by weight, organic acid calcium salt content: 51% by weight)

Comparative Example  One

Lubricant composition (TBN: 9.6 mg KOH / g, organic acid calcium salt content: 1.2 wt%) was prepared using the following calcium alkyl salicylate dispersant:

Unsulfated calcium alkyl salicylate dispersant of alkyl group having 20 to 28 carbon atoms (TBN: 230 mg KOH / g, petroleum medium content: about 32% by weight, organic acid calcium salt content: 42.5% by weight)

The determination of the organic acid calcium salt content (soap content) and evaluation of high temperature detergency were made by the following method:

(1) Determination of the content of organic acid calcium salt (soap content)

The detergent was subjected to the conventional dialysis method of separating mineral oil and low molecular weight components using a rubber membrane. Residue (A) was an effective detergent component. Separately, the amount of carbon dioxide of the detergent was determined. Based on the carbon dioxide content and the calcium content separately determined, the content of calcium carbonate (overbased component content (B)) was determined. The organic acid calcium salt (soap component) was calculated by subtracting (B) from (A).

(2) Evaluation of high temperature cleaning power

The lubricating oil composition was subjected to the hot tube test (KES-07-803) described below at 300 and 305.

The glass tube (2mm inside diameter) was placed perpendicular to the Heater Block. Lubricating oil composition and air in the glass tube were fed from the bottom of the tube at a rate of 0.31 cc / hour and 10 cc / min, respectively. This supply was continued for 16 hours to keep the thermal breaker at a predetermined temperature. After the supply was finished, the glass tube was taken out and the precipitate in the tube was examined. Evaluation was performed with 10 points (highest). A score of 10 means no precipitate was observed.

(3) Low temperature viscosity

Low temperature viscosity (cP) was determined using an MRV (described in ASTM D4684) viscometer at −35.

Evaluation and Measurement Results oil High temperature
300 ℃ Detergent
305 ℃ Low temperature
Viscosity Example 1
Example 2 6.0
6.5 6.0
6.0 25,200
25,100 Comparative Example 1 5.0 4.5 Not measurable

As shown in the above results, the lubricating oil composition according to the present invention (Examples 1 and 2) comprising calcium alkyl salicylates of alkyl groups having 14 to 18 carbon atoms has very extreme temperature conditions such as 300 ° C and 305 ° C. Improved high temperature detergency under low temperature and also showed low viscosity at low temperature. In contrast, the lubricating oil composition of Comparative Example 1 comprising one calcium alkylsalicylate having 20 to 28 carbon atoms of alkyl group showed poor high temperature cleaning power and satisfactory low viscosity at low temperature (i.e., too viscous to be measured). Couldn't show).

Example  3

Lubricating oil composition (TBN: 9.6 mg KOH / g, organic acid calcium salt content: 1.1 wt%) was prepared using the following two calcium alkyl salicylate detergent 1: 1 mixtures (in terms of calcium content ratio):

Unsulfated calcium alkyl salicylate detergent of alkyl group having 14 to 18 carbon atoms (TBN: 220 mg KOH / g, petroleum medium content: about 30% by weight, organic acid calcium salt content: 49% by weight)

Unsulfated calcium alkylsalicylate detergent of alkyl group having 20 to 28 carbon atoms (TBN: 320 mg KOH / g, petroleum medium content: about 35 wt%, organic acid calcium salt content: 32.5 wt%)

Example  4

Lubricating oil composition (TBN: 9.6 mg KOH / g, organic acid calcium salt content: 1.1 wt%) was prepared using the following two calcium alkyl salicylate detergent 1: 1 mixtures (in terms of calcium content ratio):

Unsulfated calcium alkylsalicylate detergent of alkyl group having 14 to 18 carbon atoms (TBN: 225 mg KOH / g, petroleum medium content: at most about 30% by weight, organic acid calcium salt content: 51% by weight)

Unsulfated calcium alkylsalicylate detergent of alkyl group having 20 to 28 carbon atoms (TBN: 320 mg KOH / g, petroleum medium content: about 35 wt%, organic acid calcium salt content: 32.5 wt%)

The determination of the organic acid calcium salt content (soap content) and the evaluation of the high temperature detergency were provided by the above method.

Evaluation and Measurement Results oil High temperature
300 ℃ Detergent
305 ℃ Low temperature
Viscosity Example 3
Example 4 6.0
6.5 5.0
5.0 25,200
25,100

As can be seen from the above results, the lubricating oil composition according to the present invention (Examples 3 and 4) comprising two calcium alkyl salicylates of alkyl groups having different carbon atoms has a high temperature under very extreme temperature conditions such as 300 ° C and 305 ° C. Improved detergency and lower viscosity at lower temperatures.

Claims (9)

A lubricating oil composition for internal combustion engine lubrication that is operated using fuel oil having a sulfur content of less than 0.005% by weight,
The following components a) to d) dissolved or dispersed in a base oil having a sulfur content of less than 0.1% by weight and containing from 0.1% to 1.1% by weight of sulphide ash, from 0.01% to 0.12% by weight of phosphorus, from 0.01% to 0.5% Lubricant compositions for lubrication of internal combustion engines with a sulfur content of% and chlorine content of less than 150 ppm:
a) an ashless dispersant of 0.01 to 0.3% by weight, based on the nitrogen content, selected from the group consisting of alkenyl succinimide, alkyl succinimide, or derivatives thereof;
b) comprises an organic acid calcium salt under conditions with a sulfur content of less than 3% by weight and a total base number of from 10 to 350 mg KOH / g, wherein the lubricating oil composition comprises from 0.2 to 7% by weight of organic acid calcium salt by weight of the composition; A calcium alkylsalicylate detergent of 0.1 to 1% by weight, based on a sulfated ash content, including an unsulfated calcium alkylsalicylate detergent having an alkyl group having 14 to 18 carbon atoms;
c) 0.01 to 0.12% by weight zinc phosphate anti-wear agent, based on phosphorus content, selected from the group consisting of zinc dialkyldithiophosphate and zinc dihydrocarbylphosphate; And
d) 0.01 to 5% by weight of an inhibitor of oxidation, selected from the group consisting of antioxidant phenol compounds and antioxidant amine compounds,
Here, the sulfidated ash content, phosphorus content, sulfur content and weight% given in a) to d) are values based on the amount of lubricating oil composition. The method of claim 1,
The calcium alkylsalicylate detergent of component b) has a total base number in the range of 30 to 300 mg KOH / g. The method of claim 1,
The non-sulphide calcium alkylsalicylate detergent having an alkyl group having 14 to 18 carbon atoms has a total base number in the range of 100 to 250 mg KOH / g. The method of claim 1,
Ashless dispersants of component a) include succinimide or derivatives thereof obtained by reaction of polybutenylsuccinic anhydride with polyamine prepared by thermal reaction of polybutene with maleic anhydride in the absence of chlorine or chlorine-containing compounds Lubricating oil composition, characterized in that. The method of claim 1,
The lubricating oil composition comprises a molybdenum-containing compound of 0.01 to 5% by weight. The method of claim 1,
The lubricating oil composition is characterized in that the total base number in the range of 1 to 17 mg KOH / g. The method of claim 1,
The lubricating oil composition is a lubricating oil composition comprising a viscosity index improver and is a multi grade engine oil that is an oil of 0W5, 0W10, 0W15, 0W20, 0W30, 5W20, 5W30, 10W20, or 10W30. The method of claim 1,
Wherein the lubricating oil composition is used to lubricate a diesel engine operating with a fuel oil having a sulfur content of less than 0.005% by weight and mounted on a land vehicle. A method of operating a diesel engine mounted on a land vehicle using fuel oil having a sulfur content of less than 0.005% by weight and the lubricating oil composition of claim 1.