JP2013129832A - Method of reducing rate of depletion of basicity of lubricating oil composition in engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of reducing the rate of depletion of basicity of a lubricating oil composition in use in an engine for marine cylinder, trunk piston engine, gas engine, crankcase or the like.SOLUTION: A lubricating oil composition includes at least one overbased alkali metal or alkaline earth metal detergent expressed as follows. One or more compounds or its alkaline earth metal salt are/is added. The compounds of formula (I) are preferably methylene-bridged alkyl phenols or ethoxylated methylene-bridged alkyl phenols.

Description

  The present invention relates to a method for reducing the rate of decrease in basicity (as measured by ASTM D2896) of a lubricating oil composition in use in an engine, the lubricating oil composition comprising at least Contains a kind of oil-soluble overbased alkali metal or alkaline earth metal detergent. In particular, the present invention relates to a method for reducing the rate of reduction of the basicity (measured by ASTM D2896) of a lubricating oil composition for use in an engine, the lubricating oil composition comprising sulfate ash (SASH). At least one oil-soluble overbased alkali metal or alkaline earth metal detergent. The lubricating oil composition is preferably a marine cylinder lubricant, trunk piston engine oil, gas engine oil or crankcase lubricating oil composition (including passenger car motor oil and heavy duty diesel motor oil).

  The lubricating oil composition includes an oil soluble overbased detergent to provide alkalinity to neutralize the sulfur acid resulting from the high sulfur fuel. They also prevent harmful carbon and sludge deposits, which can result in engine shutdown and repair. Overbased detergents usually have a TBN in the range of 50 to 500, preferably 250 to 450 mg KOH / g (ASTM D2896) and are usually overbased alkaline earth metal detergents such as overbased sulfonic acids. Calcium, phenate and salicylate. It is important that the basicity provided by the overbased detergent is kept as long as possible. This is because this ensures a longer oil life and better engine protection over a longer period of time. It is also important that the ash level is not increased. This is because excessive sulfate ash levels can result in increased deposits in the piston and exhaust gas circuits (including heat recovery systems and aftertreatment devices).

  The present invention relates to the problem of reducing the rate of reduction of the basicity (as measured by ASTM D2896) of a lubricating oil composition for use in an engine. The present invention also relates to the problem of reducing the rate of decrease in basicity (as measured by ASTM D2896) of lubricating oil compositions for use in engines without increasing sulfate ash.

According to a first aspect of the present invention, there is provided a method for reducing the rate of decrease in basicity (measured by ASTM D2896) of a lubricating oil composition for use in an engine, the lubricating oil composition comprising at least A type of oil-soluble overbased alkali metal or alkaline earth metal detergent, the method comprising adding to the lubricating oil composition one or more compounds of formula (I), or alkaline earth metal salts of compounds of formula (I) Adding.

Where
x is 1 to 50, preferably 1 to 40, more preferably 1 to 30;
R ¹ and R ² are H, a hydrocarbyl group having 1 to 12 carbon atoms, or a hydrocarbyl group having 1 to 12 carbon atoms and at least one heteroatom,
R is a hydrocarbyl group having 9 to 100, preferably 9 to 70, most preferably 9 to 50 carbon atoms, and n is 0 to 10.
In the compound of formula (I), n is preferably 0. In the compound of formula (I), x is preferably 1. In the compounds of formula (I), R is preferably 9-20 carbon atoms, more preferably 9-15 carbon atoms. In the compound of formula (I), R is preferably branched.
In the compound of formula (I), R ¹ is preferably H, R ² is preferably H, and R is in the para position relative to the —O— [CH ₂ CH ₂ O] _n H group. Preferably there is.
It is preferred that the compound of formula (I) is a methylene bridged alkylphenol or a methylene bridged ethoxylated alkylphenol.
The compound of formula (I) preferably comprises less than 1 mol%, more preferably less than 0.5 mol%, most preferably less than 0.1 mol% unreacted alkylphenol.
In compounds of formula (I), more than 60 mol%, more preferably more than 70 mol%, more preferably more than 80 mol%, more preferably more than 90 mol%, or most preferably more than 95 mol%. n is preferably 1.
In the compound of the formula (I), n is 2 or more with respect to less than 5 mol%, and for example, di-oxyalkylation, tri-oxyalkylation and tetra-oxyalkylation are preferable.
Alkaline earth metal salts of the compounds of formula (I) are, for example, calcium salts, magnesium salts, barium salts or strontium salts. Calcium or magnesium is preferred, and calcium is particularly preferred.

The lubricating oil composition is preferably a marine cylinder lubricant, trunk piston engine oil, gas engine oil or crankcase lubricating oil composition (including passenger car motor oil and heavy duty diesel motor oil).
When the lubricating oil composition is a marine cylinder lubricant, its TBN (as measured by ASTM D2896) is preferably at least 20, more preferably at least 40 to about 70 mg KOH / g.
When the lubricating oil composition is a trunk piston engine oil, its TBN (measured by ASTM D2896) is preferably at least 10, more preferably at least 20, and most preferably 30-55 mg KOH / g.
When the lubricating oil composition is a gas engine oil, its TBN (measured by ASTM D2896) is preferably at least 4, more preferably 5-15 mg KOH / g.
When the lubricating oil composition is a crankcase oil, its TBN (as measured by ASTM D2896) is preferably at least 5, more preferably at least 6-18 mg KOH / g.
It is preferred that the lubricating oil composition is a marine cylinder lubricant.
In accordance with the present invention, one or more compounds of formula (I), or alkaline earth thereof, for reducing the rate of decrease in basicity (as measured by ASTM D2896) of a lubricating oil composition for use in an engine. There is also provided the use of an alkali metal salt, the lubricating oil composition comprising at least one oil soluble overbased alkali metal or alkaline earth metal detergent.

Wherein x is 1 to 50, preferably 1 to 40, more preferably 1 to 30, and R ¹ and R ² are H, a hydrocarbyl group having 1 to 12 carbon atoms, or 1 to 12 A hydrocarbyl group having carbon atoms and at least one heteroatom, wherein R is a hydrocarbyl group having 9 to 100, preferably 9 to 70, most preferably 9 to 50 carbon atoms, and n Is 0-10.

It is a graph which shows the result of the beaker test about an example and standard oil.

A compound of formula (I) or an alkaline earth metal salt thereof is shown as follows.

Where
x is 1 to 50, preferably 1 to 40, more preferably 1 to 30;
R ¹ and R ² are H, a hydrocarbyl group having 1 to 12 carbon atoms, or a hydrocarbyl group having 1 to 12 carbon atoms and at least one heteroatom,
R is a hydrocarbyl group having 9 to 100, preferably 9 to 70, most preferably 9 to 50 carbon atoms, and n is 0 to 10.
Alkaline earth metal salts of the compounds of formula (I) are, for example, calcium salts, magnesium salts, barium salts or strontium salts. Calcium or magnesium is preferred, and calcium is particularly preferred.

In the compound of formula (I), n is preferably 0. In the compound of formula (I), x is preferably 1. In the compounds of formula (I), R is preferably 9-20 carbon atoms, more preferably 9-15 carbon atoms. In the compound of formula (I), R is preferably branched. In the compound of formula (I), R ¹ and R ² are preferably H.
In the compound of formula (I), R ¹ and are preferably H, R ² is preferably H, and R is in the para position relative to the —O— [CH ₂ CH ₂ O] _n H group. It is preferable that n is 1 or more, preferably 1 to 10. Reference is made to EP 2374866A, the contents of which are included herein, for further details of compounds of formula (I) when n is 1 or more. In compounds of formula (I), n is 1 for more than 60 mol%, more preferably more than 70 mol%, more preferably more than 80 mol%, more preferably more than 90 mol%, or most preferably more than 95 mol%. Preferably there is. In the compound of the formula (I), n is preferably 2 or more with respect to less than 5 mol%, and for example, di-oxyalkylation, tri-oxyalkylation and tetra-oxyalkylation are preferable.
The compound of formula (I) preferably comprises less than 1 mol%, more preferably less than 0.5 mol%, most preferably less than 0.1 mol% unreacted alkylphenol.
The compounds of formula (I) have the advantage that they do not contain metals. Furthermore, they show no negative interaction with the dispersant.

It is preferred that the compound of formula (I) is a hydrocarbyl phenol formaldehyde condensate. As used herein, the term “hydrocarbyl” means that R primarily contains hydrogen and carbon atoms, and is bonded to the remainder of the molecule through the carbon atom, It does not exclude the presence of an insufficient proportion of other atoms or groups to reduce hydrocarbon properties. It is preferred that the hydrocarbyl group contains only hydrogen and carbon atoms. Advantageously, the hydrocarbyl group is an aliphatic group, preferably an alkyl or alkylene group, in particular an alkyl group, which may be linear or branched. R is preferably an alkyl group or an alkylene group. R is preferably branched.
It is preferred that the hydrocarbyl phenol aldehyde condensate has a weight average molecular weight (Mw) in the range of 1000 to less than 6000, preferably less than 4000, as measured by GPC. It is preferred that the hydrocarbyl phenol aldehyde condensate has a number average molecular weight (Mn) in the range of 900 to less than 4000, for example 3000, as measured by GPC. Mw / Mn is preferably in the range of 1.10 to 1.60.
The hydrocarbyl phenol aldehyde condensate is preferably obtained by a condensation reaction of at least one hydrocarbyl phenol with at least one aldehyde or ketone or their reactive equivalents in the presence of an acid catalyst such as an alkylbenzene sulfonic acid. . It is preferred that the product be stripped to remove unreacted hydrocarbylphenol, preferably to less than 5% by weight, more preferably less than 3% by weight, more preferably less than 1% by weight unreacted hydrocarbylphenol. Most preferably, the product comprises less than 0.5% by weight of unreacted hydrocarbyl phenol, for example less than 0.1% by weight.
Although basic catalysts can be used, acid catalysts are preferred. The acid catalyst may be selected from a variety of acidic compounds such as phosphoric acid, sulfuric acid, sulfonic acid, oxalic acid and hydrochloric acid. The acid may also be present as a component of a solid material, such as an acid treated clay. The amount of catalyst used may vary from 0.05% to 10% by weight of the total reaction mixture, for example from 0.1% to 1% by weight.
When n is 1 or more in formula (I), these compounds are preferably made by oxyalkylating a hydrocarbyl phenol condensate with ethylene carbonate (preferably), propylene carbonate or butylene carbonate. It can be seen that the use of carbonate for the oxyalkylation reaction gives a very good control of the "n" value and amount compared to the use of ethylene oxide or propylene oxide. Furthermore, a suitable choice of catalyst can give a product consisting of substantially all mono-oxyalkyl (ie n = 1) content. Sodium salts are preferred, especially hydroxides and carboxylates such as stearates.

In particular, the hydrocarbyl phenol aldehyde condensate is preferably a branched dodecyl phenol formaldehyde condensate, for example, a tetrapropenyl tetramer phenol formaldehyde condensate.
The hydrocarbyl phenol aldehyde condensate is about 0.1% to 20%, preferably about 0.1% to 15%, more preferably about 0.1% to 12% by weight, based on the weight of the additive concentrate. It is preferably present in the concentrate in amounts up to.
The lubricating oil composition of the present invention comprises a majority amount of oil of lubricating viscosity and a minor amount of a compound of formula I.
Oils of lubricating viscosity useful in the context of the present invention may be selected from natural lubricating oils, synthetic lubricating oils and mixtures thereof. The lubricating oil may range in viscosity from light distilled mineral oil to heavy lubricating oil, such as gasoline engine oil, lubricating mineral oil and heavy duty diesel oil. Generally, the viscosity of the oil ranges from about 2 centistokes to about 40 centistokes, particularly from about 4 centistokes to about 20 centistokes, measured at 100 ° C.
Natural oils include animal and vegetable oils (eg, castor oil, lard oil), liquid petroleum and paraffinic, naphthenic and mixed paraffin-naphthenic hydrorefined mineral oils, solvent-treated mineral oils or acid-treated mineral oils. Oils of lubricating viscosity derived from coal or shale can also be used as useful base oils.

Synthetic lubricating oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as polymerized olefins and copolymerized olefins (eg, polybutylene, polypropylene, propylene-isobutylene copolymer, chlorinated polybutylene, poly (1-hexene), poly (1 -Octene), poly (1-decene); alkylbenzenes (eg, dodecylbenzene, tetradecylbenzene, dinonylbenzene, di (2-ethylhexyl) benzene); polyphenyls (eg, biphenyl, terphenyl, alkylated polyphenols); As well as alkylated diphenyl ethers and alkylated diphenyl sulfides and their derivatives, analogs and homologs, and synthetic oils derived from the gas to liquid process from Fischer-Tropsch synthetic hydrocarbons (these Is ordinary synthetic light oil, Or referred to as “GTL” base oil).
Alkylene oxide polymers and copolymers and their derivatives (in which the terminal hydroxyl groups have been modified by esterification, etherification, etc.) constitute another class of known synthetic lubricating oils. These are polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide, and alkyl and aryl ethers of polyoxyalkylene polymers (for example, methyl-polyisopropylene glycol ether having an average molecular weight of 1000 or 1000-1500. Exemplified by diphenyl ethers of polyethylene glycol having a molecular weight), and their mono- and polycarboxylic esters, for example, acetates of tetraethylene glycol, mixed C ₃ -C ₈ fatty acid esters and C ₁₃ oxo acid diesters.
Another suitable class of synthetic lubricating oils are dicarboxylic acids (eg, phthalic acid, succinic acid, alkyl succinic acid and alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid And esters of various alcohols (for example, butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol). Specific examples of such esters include dibutyl adipate, di (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate , Dieicosyl sebacate, 2-ethylhexyl diester of linoleic acid dimer, and a complex ester produced by reacting 1 mole of sebacic acid with 2 moles of tetraethylene glycol and 2 moles of 2-ethylhexanoic acid. Can be mentioned.

Esters useful as synthetic oils, C ₅ -C ₁₂ monocarboxylic acids and polyols and polyol ethers, for example, include neopentyl glycol, trimethylol propane, pentaerythritol, those made from dipentaerythritol and tripentaerythritol or It is done.
Silicon-based oils such as polyalkyl-, polyaryl-, polyalkoxy- or polyaryloxysilicone oils and silicate oils constitute another useful class of synthetic lubricants. Such oils include tetraethyl silicate, tetraisopropyl silicate, tetra- (2-ethylhexyl) silicate, tetra- (4-methyl-2-ethylhexyl) silicate, tetra- (p-tert-butyl-phenyl) silicate, hexa- Examples include (4-methyl-2-ethylhexyl) disiloxane, poly (methyl) siloxane, and poly (methylphenyl) siloxane. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (eg, tricresyl phosphate, trioctyl phosphate, diethyl ester of decylphosphonic acid) and polymeric tetrahydrofuran.
The oil of lubricating viscosity may comprise a Group I, Group II or Group III feedstock or a base oil blend of the above feedstocks. Preferably, the oil of lubricating viscosity is a Group II or Group III feedstock, or a mixture thereof, or a mixture of a Group I feedstock and one or more Group II and Group III. The majority of the oil of lubricating viscosity is preferably Group II, Group III, Group IV or Group V feedstock or a mixture thereof. It is preferred that the feedstock, or feedstock blend, has a saturate content of at least 65%, more preferably at least 75%, such as at least 85%. Most preferably, the feedstock, or feedstock blend, has a saturate content greater than 90%. It will be preferred that the oil or oil blend has a sulfur content of less than 1% by weight, preferably less than 0.6% by weight and most preferably less than 0.4% by weight.
The volatility of the oil or oil blend (measured by Noack Volatility Test (ASTM D5880)) should be 30% or less, preferably 25% or less, more preferably 20% or less, and most preferably 16% or less. preferable. It is preferred that the viscosity index (VI) of the oil or oil blend is at least 85, preferably at least 100, most preferably from about 105 to 140.

Definitions for feedstock and base oil in the present invention can be found in the American Petroleum Institute (API) publication “Engine Oil Licensing and Authorization System”, Industrial Services, Volume 14, December 1996, Addendum 1, December 1998. Is the same. The publication categorizes feedstock as follows:
a) Group I feedstock contains less than 90% saturates and / or more than 0.03% sulfur and has a viscosity index greater than 80 and less than 120 using the test methods specified in Table 1.
b) Group II feedstocks contain 90% or more of saturates and 0.03% or less of sulfur and have a viscosity index of 80 and less than 120 using the test method specified in Table 1.
c) Group III feedstock contains 90% or more of saturates and 0.03% or less of sulfur and has a viscosity index of 120 or more using the test method specified in Table 1.
d) Group IV feedstock is polyalphaolefin (PAO).
e) Group V feedstock includes all other feedstocks not included in Group I, II, III, or IV.

Table I-Analytical methods for feedstock

Metal-containing detergents or ash-forming detergents function both as detergents to reduce or remove deposits and as acid neutralizers or rust inhibitors, thereby reducing wear and corrosion and reducing engine life. Extend. The detergent generally includes a polar head with a long hydrophobic tail, which includes a metal salt of an acidic organic compound. The salts may contain substantially stoichiometric amounts of metals, in which case they are usually described as normal or neutral salts, typically with a total alkali number or TBN (ASTM D2896 of 0 to 80). Will be measured). Large amounts of metal bases can be incorporated by reacting excess metal compounds (eg, oxides or hydroxides) with acid gases (eg, carbon dioxide). The resulting overbased detergent comprises neutralized detergent as the outer layer of a metal base (eg, carbonate) micelle. Such overbased detergents may have a TBN of 150 or greater and typically will have a TBN of 250 to 500 or greater.
Detergents that can be used include oil-soluble neutral or overbased sulfonates, phenates, sulfurized phenates of metals, in particular alkali metals or alkaline earth metals, such as sodium, potassium, lithium, calcium, and magnesium. , Thiophosphonates, salicylates, and naphthenates and other oil-soluble carboxylates. The most commonly used metals are calcium and magnesium, both of which may be present in the detergent used in the lubricant and in a mixture of calcium and / or magnesium and sodium. Particularly convenient metal detergents are neutral and overbased calcium sulfonates with a TBN of 20 to 500 TBN, and neutral and overbased calcium phenates and sulfurized phenates with a TBN of 50 to 450 . A combination of detergents (overbased or neutral or both) may be used.

Sulfonates are prepared from sulfonic acids, which are typically obtained from sulfonation of alkyl-substituted aromatic hydrocarbons, such as those obtained from petroleum fractionation or alkylation of aromatic hydrocarbons. Also good. Examples include those obtained by alkylating benzene, toluene, xylene, naphthalene, diphenyl or their halogen derivatives such as chlorobenzene, chlorotoluene and chloronaphthalene. Alkylation may be performed using an alkylating agent having from about 3 to more than 70 carbon atoms in the presence of a catalyst. The alkaryl sulfonate usually contains from about 9 to about 80 carbon atoms, preferably from about 16 to about 60 carbon atoms, per alkyl-substituted aromatic moiety.
Oil soluble sulfonates or alkaryl sulfonic acids may be neutralized with metal oxides, hydroxides, alkoxides, carbonates, carboxylates, sulfides, hydrosulfides, nitrates, borates and ethers. . The amount of metal compound is chosen with respect to the desired TBN of the final product, but typically ranges from about 100% to 220% by weight (preferably at least 125% by weight) of the stoichiometrically required amount. It is.
The metal salts of phenol and sulfurized phenol are prepared by reaction with a suitable metal compound, such as an oxide or hydroxide, and neutral or overbased products are obtained by methods known in the art. May be. Sulfurized phenol is a product in which phenol is reacted with sulfur or a sulfur-containing compound such as hydrogen sulfide, sulfur monohalide or sulfur dihalide, and generally a mixture of compounds in which two or more phenols are bridged by a sulfur-containing bridge. May be prepared.

The lubricating oil composition of the present invention may further comprise one or more ashless dispersants, which when added to the lubricating oil, effectively reduce post-use deposit formation in the engine. Ashless dispersants useful in the compositions of the present invention comprise a long backbone of oil-soluble polymer having functional groups that can associate with the particles to be dispersed. Typically, such dispersants contain an amine, alcohol, amide or ester polar moiety attached to the polymer backbone, often via a bridging group. Ashless dispersants include, for example, oil-soluble salts, esters, amino-esters, amides, imides and oxazolines of long chain hydrocarbon-substituted monocarboxylic acids and polycarboxylic acids or anhydrides thereof; thiocarboxylates of long chain hydrocarbons Derivatives; long chain aliphatic hydrocarbons having a polyamine moiety directly attached thereto; and Mannich condensation products produced by condensing long chain substituted phenols with formaldehyde and polyalkylene polyamines. The most commonly used dispersant is the known succinimide dispersant, which is the condensation product of a hydrocarbyl-substituted succinic anhydride and a poly (alkyleneamine). Both mono-succinimide dispersants and bis-succinimide dispersants (and mixtures thereof) are known.
The ashless dispersant is preferably a “high molecular weight” dispersant having a number average molecular weight (M _n ) of 4,000 or more, for example 4,000 to 20,000. The exact molecular weight range will depend on the type of polymer used to produce the dispersant, the number of functional groups present, and the type of polar functional groups used. For example, for a polyisobutylene derivatized dispersant, the high molecular weight dispersant is one produced with a polymer backbone having a number average molecular weight of from about 1680 to about 5600. A typical commercially available polyisobutylene based dispersant is functionalized with maleic anhydride (MW = 98) and derivatized with a polyamine having a molecular weight of from about 100 to about 350, from about 900 to about 2300. Polyisobutylene polymers having a number average molecular weight in the range of up to. Low molecular weight polymers may also be used to produce high molecular weight dispersants by incorporating many polymer chains into the dispersant, which can be achieved using methods known in the art.

  A preferred group of dispersants includes polyamine derivatized poly alpha-olefin dispersants, particularly those based on ethylene / butene alpha-olefins and polyisobutylene. Derived from polyisobutylene substituted with succinic anhydride groups, polyethyleneamines such as polyethylenediamine, tetraethylenepentamine; or polyoxyalkylenepolyamines such as polyoxypropylenediamine, trimethylolaminomethane; hydroxy compounds such as Especially preferred are ashless dispersants reacted with pentaerythritol; and combinations thereof. One particularly preferred dispersant combination is substituted with a succinic anhydride group, and (B) a hydroxy compound, such as pentaerythritol; (C) a polyoxyalkylene polyamine, such as polyoxypropylene diamine, or (D) a polyalkylene diamine, For example, a combination of (A) polyisobutylene reacted with polyethylene diamine and tetraethylenepentamine (from about 0.3 mol to about 2 mol (B), (C) and / or ( Using d)). Another preferred dispersant combination is (A) polyisobutenyl succinic anhydride and (B) polyalkylene polyamine, such as tetraethylenepentamine, and (C) polyhydric alcohol or polyhydroxy as described in U.S. Pat.No. 3,632,511. Contains a combination of substituted aliphatic primary amines such as pentaerythritol or trismethylolaminomethane.

Another class of ashless dispersants includes Mannich base condensation products. In general, these products are prepared from about 1 to 2.5 moles of one or more carbonyl compounds (eg, formaldehyde and polyhydroxybenzene), for example, as disclosed in US Pat. No. 3,442,808. Paraformaldehyde) and about 0.5 to 2 moles of polyalkylene polyamine. Such Mannich base condensation products may include a polymer product of metallocene catalyzed polymerization as a substituent on the benzene group, or substituted with succinic anhydride in a manner similar to that described in US Pat. No. 3,442,808. You may make it react with the compound containing such a polymer. Examples of functionalized and / or derivatized olefin polymers synthesized using metallocene catalyst systems are described in the above identified publications.
The dispersant may be further post treated by various conventional post treatments such as boriding, generally as taught in US Pat. Nos. 3,087,936 and 3,254,025. Boron of the dispersant is sufficient to provide the acyl nitrogen-containing dispersant with about 0.1 to about 20 atomic ratios of boron for each mole of acylated nitrogen composition, such as boron compounds such as boron oxide, boron halide. , Easily achieved by treatment with boronic acid and esters of boronic acid. Useful dispersants include from about 0.05% to about 2.0%, for example, from about 0.05% to about 0.7% by weight boron. Boron, which appears in the product as a dehydrated boric acid polymer (primarily (HBO ₂ ) ₃ ), is believed to bind to dispersant imides and diimides as amine salts, for example, metaborates of diimides. Boridation is carried out with about 0.5% to 4% by weight of boron compound, preferably about 1% to about 3% by weight (based on the weight of acyl nitrogen compound), preferably boric acid, usually as a slurry. This can be done by adding to the nitrogen compound and heating with stirring from about 135 ° C. to about 190 ° C., for example from 140 ° C. to 170 ° C. for about 1 hour to about 5 hours, followed by nitrogen stripping. Alternatively, the boron treatment can be performed by adding boric acid to the hot reaction mixture of dicarboxylic acid material and amine while removing water. Other post reaction methods commonly known in the art may also be applied.

The dispersant may also be further post-treated by reaction with so-called “capping agents”. Typically, nitrogen-containing dispersants have been “capped” to alleviate the detrimental effects such dispersants have on fluoroelastomer engine seals. Many capping agents and methods are known. Of the known “capping agents”, those that convert the basic dispersant amino group to a non-basic moiety (eg, an amide group or an imide group) are optimal. Reactions of nitrogen-containing dispersants with alkyl acetoacetates (eg, ethyl acetoacetate (EAA)) are described, for example, in US Pat. Nos. 4,839,071, 4,839,072 and 4,579,675. The reaction of nitrogen-containing dispersants with formic acid is described, for example, in US Pat. No. 3,185,704. Reaction products of nitrogen-containing dispersants and other suitable capping agents are described in U.S. Pat. Nos. 4,663,064 (glycolic acid); 4,612,132, 5,334,321, 5,356,552, 5,716,912, and 5,849,676. 5,861,363 (alkyl carbonates and alkylene carbonates such as ethylene carbonate); 5,328,622 (mono-epoxide); 5,026,495, 5,085,788, 5,259,906, 5,407,591 (poly ( For example, bis) -epoxide) and 4,686,054 (maleic anhydride or succinic anhydride). The above list is not exclusive and other capping methods for nitrogen-containing dispersants are known to those skilled in the art.
For proper piston deposit control, the nitrogen-containing dispersant is added to the lubricating oil composition in an amount that provides from about 0.03% to about 0.15%, preferably from about 0.07% to about 0.12%, by weight of nitrogen. obtain.
Ashless dispersants are basic in nature, therefore, depending on the nature of the polar groups and whether the dispersant is borated or treated with a capping agent, about 5 to about 200 mg KOH / It has a TBN which may be g. However, high levels of basic dispersant nitrogen are known to have detrimental effects on fluoroelastic materials commonly used to form engine seals and are therefore the minimum required to provide piston deposit control. It is preferred to use an amount of dispersant with substantially no dispersant having a TBN greater than 5, or preferably no dispersant at all. It will be preferred that the amount of dispersant used contributes a TBN of 4 or less, preferably 3 mg KOH / g or less to the lubricating oil composition. More preferably, the dispersant provides no more than 30%, preferably no more than 25% of the TBN of the lubricating oil composition.

Additional additives may be incorporated into the compositions of the present invention to satisfy special requirements. Examples of additives that may be included in the lubricating oil composition are metal rust inhibitors, viscosity index improvers, corrosion inhibitors, oxidation inhibitors, friction modifiers, other dispersants, antifoaming agents, abrasion resistance. Wear and pour point depressants. Some are described in more detail below.
Dihydrocarbyl dithiophosphate metal salts are frequently used as antiwear and antioxidant agents. The metal may be an alkali metal or alkaline earth metal, or aluminum, lead, tin, molybdenum, manganese, nickel or copper. Zinc salts are most commonly used in lubricating oils in amounts of 0.1 to 10% by weight, preferably 0.2 to 2% by weight, based on the total weight of the lubricating oil composition. They are first produced according to known techniques, usually by reaction of one or more alcohols or phenols with P ₂ S ₅ to produce dihydrocarbyl dithiophosphate (DDPA) and then neutralize the produced DDPA with a zinc compound. It may be prepared. For example, dithiophosphoric acid may be made by reacting a mixture of primary and secondary alcohols. Also, a wide variety of dithiophosphoric acids can be prepared when one hydrocarbyl group is completely secondary in character and the other hydrocarbyl group is completely primary in character. Any basic or neutral zinc compound can be used to make the zinc salt, but oxides, hydroxides and carbonates are most commonly used. Commercial additives frequently contain excess zinc due to the use of excess basic zinc compounds during the neutralization reaction.

A preferred zinc dihydrocarbyl dithiophosphate is an oil-soluble salt of dihydrocarbyl dithiophosphoric acid, which can be represented by the following formula:

In which R and R ′ contain 1 to 18, preferably 2 to 12 carbon atoms, and are alkyl, alkenyl, aryl, arylalkyl, alkaryl and alicyclic radicals. It may be the same or different hydrocarbyl groups containing such groups. Particularly preferred as R and R ′ groups are alkyl groups of 2 to 8 carbon atoms. Thus, these radicals are for example ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, amyl, n-hexyl, i-hexyl, n-octyl, decyl, dodecyl, octadecyl. 2-ethylhexyl, phenyl, butylphenyl, cyclohexyl, methylcyclopentyl, propenyl, butenyl. In order to obtain oil solubility, the total number of carbon atoms (ie, R and R ′) in the dithiophosphoric acid will generally be about 5 or greater. Thus, zinc dihydrocarbyl dithiophosphate can include zinc dialkyldithiophosphate. The present invention relates to phosphorus levels from about 0.02% to about 0.12%, such as from about 0.03% to about 0.10%, or from about 0.05% to about 0.08% by weight, based on the total weight of the composition. May be particularly beneficial when used with lubricant compositions comprising In one preferred embodiment, the lubricating oil composition of the present invention comprises a zinc dialkyldithiophosphate derived primarily (eg, 50 mol% or more, such as 60 mol% or more) from a secondary alcohol.
Antioxidants or antioxidants reduce the tendency of mineral oil to deteriorate during use. Oxidative degradation can be evidenced by sludge in the lubricant, deposits such as varnish on the metal surface, and thickening. Such oxidation inhibitors include hindered phenols, preferably alkaline earth metal salts of alkylphenol thioesters having C ₅ -C ₁₂ alkyl side chains, calcium nonylphenol sulfides, oil-soluble phenates and sulfurized phenates, phosphosulfurized or sulfurized hydrocarbons. , Phosphorus esters, metal thiocarbamates, oil-soluble copper compounds as described in US Pat. No. 4,867,890, and molybdenum-containing compounds.

Typical oil-soluble aromatic amines having at least two aromatic groups bonded directly to one amine nitrogen contain from 6 to 16 carbon atoms. The amine may contain more than two aromatic groups. A compound having a total of at least three aromatic groups (two aromatic groups are covalently bonded or bonded by an atom or group (eg, an oxygen or sulfur atom, or a —CO— group, a —SO ₂ — group or an alkylene group) And two are directly bonded to one amine nitrogen) are also considered aromatic amines having at least two aromatic groups bonded directly to the nitrogen. The aromatic ring is typically substituted with one or more substituents selected from alkyl groups, cycloalkyl groups, alkoxy groups, aryloxy groups, acyl groups, acylamino groups, hydroxy groups, and nitro groups.
Multiple antioxidants are usually used in combination. In one preferred embodiment, the lubricating oil composition of the present invention comprises from about 0.1% to about 1.2% by weight amine antioxidant and from about 0.1% to about 3% phenolic antioxidant. . In another preferred embodiment, the lubricating oil composition of the present invention comprises from about 0.1% to about 1.2% by weight amine-based antioxidant, from about 0.1% to about 3% by weight phenolic antioxidant and lubricant. An amount of molybdenum compound is provided to provide the oil composition with about 10 ppm to about 1000 ppm of molybdenum.
Representative examples of suitable viscosity modifiers are polyisobutylene, copolymers of ethylene and propylene, polymethacrylates, methacrylate copolymers, copolymers of unsaturated dicarboxylic acids and vinyl compounds, copolymers of styrene and acrylic esters, and styrene / isoprene, styrene Not only partially hydrogenated copolymers of / butadiene and isoprene / butadiene, but also partially hydrogenated homopolymers of butadiene and isoprene.

Friction modifiers and fuel economy agents that are compatible with the other components of the final oil may also be included. Examples of such materials include glyceryl monoesters of higher fatty acids such as glyceryl mono-oleate; esters of long chain polycarboxylic acids and diols such as butanediol esters of dimerized unsaturated fatty acids; oxazoline compounds And alkoxylated alkyl-substituted mono-amines, diamines and alkyl ether amines such as ethoxylated tallow amine and ethoxylated tallow ether amine.
Other known friction modifiers include oil-soluble organomolybdenum compounds. Such organomolybdenum friction modifiers also impart antioxidant and anti-wear credits to the lubricating oil composition. Examples of such oil-soluble organic molybdenum compounds include dithiocarbamate, dithiophosphate, dithiophosphinate, xanthate, thioxanthate, sulfide, and the like, and mixtures thereof. Molybdenum dithiocarbamate, dialkyldithiophosphate, alkylxanthate and alkylthioxanthate are particularly preferred.
Furthermore, the molybdenum compound may be an acidic molybdenum compound. These compounds react with basic nitrogen compounds as measured by ASTM test D-664 or D-2896 titration procedure and are typically hexavalent. Molybdic acid, ammonium molybdate, sodium molybdate, potassium molybdate, and other alkaline metal molybdates and other molybdenum salts, such as sodium hydrogen molybdate, MoOCl ₄ , MoO ₂ Br ₂ , Mo ₂ O ₃ Cl ₆ , Molybdenum trioxide or similar acidic molybdenum compounds.

Among the beneficial molybdenum compounds in the compositions of the present invention are the formulas
Mo (ROCS ₂ ) ₄ and
Mo (RSCS ₂ ) ₄
Wherein R is generally an organic group of 1 to 30 carbon atoms, preferably 2-12 carbon atoms, selected from the group consisting of alkyl, aryl, aralkyl and alkoxyalkyl, most preferably 2 Is alkyl of ~ 12 carbon atoms)
There are organic molybdenum compounds. Particularly preferred is a dialkyldithiocarbamate of molybdenum.
Another group of useful organomolybdenum compounds in the lubricating compositions of the present invention are trinuclear molybdenum compounds, particularly those of the formula Mo ₃ S _k L _n Q _z and mixtures thereof, where L represents the compound. Independently selected ligands having an organic group with a sufficient number of carbon atoms to be soluble or dispersible in oil, n is from 1 to 4, k is from 4 to 7, Is selected from the group of neutral electron donating compounds such as water, amines, alcohols, phosphines and ethers, and z ranges from 0 to 5 and includes non-stoichiometric values. At least 21 total carbon atoms, such as at least 25, at least 30, or at least 35 carbon atoms should be present in all ligand organic groups.
The dispersant-viscosity index improver functions as both a viscosity index improver and a dispersant. Examples of dispersant-viscosity index improvers include amines, such as polyamines, and hydrocarbyl-substituted mono- or di-carboxylic acids (the hydrocarbyl substituent is a chain of sufficient length to impart viscosity index improving properties to the compound. Reaction product). Generally, the viscosity index improver dispersant is ₄ to 20 C ₄ -C ₂₄ unsaturated esters of vinyl alcohol or C ₃ -C ₁₀ unsaturated mono-carboxylic acids or C ₄ -C ₁₀ di-carboxylic acids, for example. Polymers of unsaturated nitrogen-containing monomers having 5 carbon atoms; polymers of C ₂ -C ₂₀ olefins and unsaturated C ₃ -C ₁₀ mono- or di-carboxylic acids neutralized with amines, hydroxylamines or alcohols; or C _Further by either grafting _4- C ₂₀ unsaturated nitrogen-containing monomers onto it or by grafting unsaturated acids onto the polymer backbone and then reacting the carboxylic acid groups of the grafted acid with amines, hydroxyamines or alcohols. It may be a polymer of reacted ethylene and C ₃ -C ₂₀ olefins.

Pour point depressants (otherwise known as lube oil flow improvers (LOFI)) lower the minimum temperature at which liquid can flow or be injected. Such additives are known. Representative of these additives that improve the low temperature fluidity of the liquid are C ₈ -C ₁₈ dialkyl fumarate / vinyl acetate copolymers, and polymethacrylates. Foam control is provided by a polysiloxane type antifoaming agent such as silicone oil or polydimethylsiloxane.
Some of the above additives can provide many effects, thus, for example, a single additive can act as a dispersant-oxidation inhibitor. This approach is well known and need not be further described herein.
In the present invention, it may also be preferred to include an additive that maintains the viscosity stability of the blend. Thus, it has been observed that additives containing polar groups achieve a suitable low viscosity in the preblend stage, but thicken when certain compositions are stored for extended periods of time. Additives that are effective in controlling this thickening include long chain hydrocarbons functionalized by reaction with mono- or dicarboxylic acids or anhydrides used in the preparation of the ashless dispersants disclosed above. Including.
When the lubricating composition includes one or more of the above additives, each additive is typically blended into the base oil in an amount that allows the additive to provide its desired function. Representative effective amounts of such additives when used in different lubricants are listed below. All listed values are described as mass% active ingredients.

Marine diesel cylinder lubricant (“MDCL”)
Marine diesel cylinder lubricants may use 10-35% by weight, preferably 13-30% by weight, most preferably 16-24% by weight concentrate or additive package, the balance being feedstock. It preferably comprises an oil with a lubricating viscosity of at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight, based on the total weight of MDCL.
Preferably, the fully formulated MDCL has a TBN of at least 20, for example from about 30 to about 100 mg KOH / g (ASTM D2896). More preferably, these compositions have a TBN of at least 40, such as from about 40 to about 70 mg KOH / g.
MDCL preferably has a sulfate ash (SASH) content (ASTM D-874) of about 12% by weight or less, preferably about 11% by weight or less, more preferably about 10% by weight or less, for example 9% by weight or less. .

The following are examples of typical ratios of additives in MDCL.

Trunk piston engine oil (“TPEO”)
Trunk piston engine oil may use a concentrate or additive package of 7-35 wt%, preferably 10-28 wt%, more preferably 12-24 wt%, with the balance being feedstock.
The fully formulated trunk piston engine oil preferably has a TBN of at least 10, for example from about 15 to about 60 mg KOH / g (ASTM D2896). More preferably, these compositions have a TBN of at least 20, for example from about 30 to about 55 mg KOH / g.
The fully formulated trunk piston engine oil preferably has a sulfate ash (SASH) content (ASTM D-874) of about 7% by weight or less, preferably about 6.5% by weight or less, for example 6.3% by weight or less.

The following are typical ratios of additives in TPEO.

The crankcase lubricant fully formulated crankcase lubricating oil composition preferably has a TBN of at least 6, for example from about 6 to about 18 mg KOH / g (ASTM D2896). More preferably, these compositions have a TBN of at least 8.5, such as from about 8.5 or 9 to about 18 mg KOH / g.
The fully formulated crankcase lubricating oil composition has a sulfate ash (SASH) content (ASTM D- of about 1.1 wt% or less, preferably about 1.0 wt% or less, more preferably about 0.8 wt% or less, for example 0.5 wt% or less. 874).

The following are examples of typical ratios of additives in crankcase lubricants (including passenger car motor oil and heavy duty diesel motor oil).

The fully formulated lubricating oil composition of the present invention preferably has a sulfur content of less than about 0.4% by weight. For crankcase applications, it is preferred that the fully formulated lubricating oil composition has a sulfur content of less than about 0.35 wt%, more preferably less than about 0.3 wt%, such as less than about 0.20 wt%. Preferably, the fully formulated lubricating oil composition (oil of lubricating viscosity + all additives and additive diluents) has a Noack volatility (ASTM D5880) of 13 or less, such as 12 or less, preferably 10 or less. Let's go. The fully formulated lubricating oil composition of the present invention preferably has 1200 ppm or less of phosphorus, such as 1000 ppm or less, or 800 ppm or less, such as 600 ppm or less, or 500 or 400 ppm or less.
It may not be necessary to prepare one or more additive concentrates containing the additive (the concentrate is sometimes referred to as an additive package), but it may be desirable so that several additives are added to the oil simultaneously To produce a lubricating oil composition. The concentrate for the preparation of the lubricating oil composition of the present invention is, for example, from about 0.1% to about 30%, preferably from 0.5% to 30% by weight of one or more compounds of formula (I); About 10% to about 40% by weight of a nitrogen-containing dispersant; about 2% to about 20% by weight of an amine-based antioxidant, a phenolic antioxidant, a molybdenum compound, or a mixture thereof; about 5% by weight % To 40% by weight detergent; and about 2% to about 20% by weight metal dihydrocarbyl dithiophosphate.
The final composition may use a concentrate of 5 to 25% by weight, preferably 5 to 18% by weight, typically 10 to 15% by weight, the remainder being an oil of lubricating viscosity and viscosity modification It is an agent.
All weight (and mass) percentages expressed herein are based on the active ingredient (AI) content of the additive and / or additive package (excluding the associated diluent). However, detergents are usually produced in diluent oil, which is not removed from the product, and detergent TBN is usually provided to the active detergent in the relevant diluent oil. Thus, weight (and mass)% is the total weight (and mass)% of the active ingredient and associated diluent oil (unless otherwise indicated) when referring to detergents.
The invention will be further understood with reference to the following examples, in which all parts are parts by weight (or parts by weight) unless otherwise stated.

It is important that the basicity introduced into the lubricating oil composition is maintained as long as possible. It is also important that the time that the TBN level and TAN level cross is as long as possible. Both of these measures ensure longer oil life and better engine protection over a longer period of time.
A beaker test was performed on three lubricating oil compositions: reference oil, Example 1 and Example 2. The base oil contained 2.475% by weight of overbased calcium sulfonate detergent (with 425 mg KOH / g TBN) in the base oil. Example 1 includes 2.475% by weight overbased calcium sulfonate detergent (with 425 mg KOH / g TBN) and 1.369% by weight poly {[2-hydroxy-5- (tetrapropenyl) -1, 3-phenylene] methylene}. Example 2 includes 2.475% by weight overbased calcium sulfonate detergent (with 425 mg KOH / g TBN) and 1.369% by weight poly {[2-hydroxyethoxy-5- (tetrapropenyl) -1 in the base oil. , 3-phenylene] methylene}. All three lubricating oil compositions had 10.5 mg KOH / g TBN (ASTM D2896).
Poly {[2-hydroxy-5- (tetrapropenyl) -1,3-phenylene] methylene} was prepared as follows.
Para-tetrapropenylphenol (known as 'TPP') (1 molar equivalent, commercially available), alkyl benzene sulfonic acid (0.0033 mole percent based on TPP) and toluene (30 weight percent based on TPP) in an overhead stirrer and dean -A reactor with baffles equipped with a Stark reflux device was charged. A nitrogen seal was used throughout. Agitation was increased to 160-170 rpm and the temperature ramped to 110 ° C. over 40 minutes. A 36.5% formaldehyde solution (1.18 equivalent moles of formaldehyde relative to the TPP used) was charged at a constant rate over 2 hours. The temperature was maintained at 110 ° C. during the addition. After complete addition of formaldehyde, the temperature was raised to 120 ° C. and maintained for 1 hour to remove the remaining water. The reaction was cooled to 90 ° C. and then charged with 50% sodium hydroxide solution (1.25 molar equivalents relative to alkylbenzene sulfonic acid) over 0.5 hours. The temperature was ramped to 130 ° C. over 0.5 hours and maintained for an additional hour to remove water. Depending on the equipment setup for the distillation, the intermediate was heated to 130 ° C. in vacuo for 1 hour to remove toluene. Mineral oil was used to cut back the product to 50% active ingredient.

Poly {[2-hydroxyethoxy-5- (tetrapropenyl) -1,3-phenylene] methylene} was prepared as follows.
Para-tetrapropenylphenol (known as 'TPP') (1 molar equivalent, commercially available), alkyl benzene sulfonic acid (0.0033 mole percent based on TPP) and toluene (30 weight percent based on TPP) in an overhead stirrer and dean -A reactor with baffles equipped with a Stark reflux device was charged. A nitrogen seal was used throughout. Agitation was increased to 160-170 rpm. The temperature was ramped up to 110 ° C. over 40 minutes. A 36.5% formaldehyde solution (1.18 equivalent moles of formaldehyde relative to the TPP used) was charged at a constant rate over 2 hours. The temperature was maintained at 110 ° C. during the addition. After complete addition of formaldehyde, the temperature was raised to 120 ° C. and maintained for 1 hour to remove the remaining water. The reaction was cooled to 90 ° C. and then charged with 50% sodium hydroxide solution (2.22 wt% with respect to TPP) over 0.5 hours. The temperature was ramped to 130 ° C. over 0.5 hours and maintained for an additional hour to remove water. Depending on the equipment setup for the distillation, the intermediate was heated to 130 ° C. in vacuo for 1 hour to remove toluene. Xylene (30% by mass with respect to TPP) was charged while cooling to 90 ° C. The Dean Stark apparatus was switched from distillation to reflux. Using a dropping funnel, ethylene carbonate (1.02 equivalent mol to TPP) was charged over 0.5 hour. The temperature was ramped up to a reflux point of 165 ° C. over 1 hour. IR analysis was used to determine when ethylene carbonate was completely consumed (typically after 2.5 hours). The temperature was maintained at 165 ° C. and xylene was removed using vacuum distillation. Mineral oil was used to cut back the product to 50% active ingredient.
The beaker test involved titrating the oil formulation with 1.0 M sulfuric acid and analyzing TAN and TBN. The acid flow rate was 10 ml / hour, the amount of oil was 250 g, the stirring speed was 300 rpm, and the oil temperature was 95 ° C.
After testing each sample, a centrifuge step was used to remove insoluble solids prior to oil analysis.

The results are as follows.

The results are shown in the accompanying drawings.
The results show that the reference oil reaches TAN and TBN crossovers much faster than Examples 1 and 2. Therefore, the base in the reference oil is reduced much more quickly than the bases in Examples 1 and 2. In fact, Examples 1 and 2 showed no TAN and TBN crossover even at the end of the 2.5 hour test. Once the lubricating oil composition exhibits TAN and TBN crossover, the composition has insufficient base levels to neutralize the acid produced by the engine, which results in engine wear. These results are surprising. This is because Examples 1 and 2 do not contain more base than the baseline oil at the start of the test (ie, all examples started beaker testing with 10.5 mg KOH / g TBN).

Claims (14)

A method for reducing the rate of decrease in basicity (measured by ASTM D2896) of a lubricating oil composition for use in an engine, wherein the lubricating oil composition comprises at least one oil-soluble overbased alkali metal or alkaline An earth metal detergent, the method of which is added to the lubricating oil composition of formula (I):

(Where
x is 1 to 50, preferably 1 to 40, more preferably 1 to 30;
R ¹ and R ² are H, a hydrocarbyl group having 1 to 12 carbon atoms, or a hydrocarbyl group having 1 to 12 carbon atoms and at least one heteroatom,
R is a hydrocarbyl group having 9 to 100, preferably 9 to 70, most preferably 9 to 50 carbon atoms, and n is 0 to 10.
Adding said one or more compounds, or an alkaline earth metal salt thereof.   The method of claim 1, wherein n in formula (I) is 0.   The method according to claim 1 or 2, wherein x in formula (I) is 1.   The process according to any one of claims 1 to 3, wherein R in formula (I) is 9 to 20, preferably 9 to 15 carbon atoms.   The method according to any one of claims 1 to 4, wherein R in formula (I) is branched. 6. The method according to claim ^{1, wherein} R ¹ = H, R ² = H and R is para to the —O— [CH ₂ CH ₂ O] _n H group in formula (I). Method.   7. A process according to any one of claims 1 to 6, wherein the compound of formula (I) comprises less than 1 mol%, preferably less than 0.5 mol%, most preferably less than 0.1 mol% unreacted alkylphenol.   N = 1 for more than 60 mol%, preferably more than 70 mol%, preferably more than 80 mol%, preferably more than 90 mol%, or most preferably more than 95 mol% of a compound of formula (I), Item 8. The method according to any one of Items 1 to 7.   The process according to any one of claims 1 to 8, wherein the alkaline earth metal salt of the compound of formula (I) is a calcium salt or a magnesium salt.   10. Less than 5 mol% of the compound of formula (I), where n> 2, eg di-oxyalkylation, tri-oxyalkylation and tetra-oxyalkylation. The method described.   11. A process according to any one of claims 1 to 10, wherein the compound of formula (I) is a methylene bridged alkylphenol or a methylene bridged ethoxylated alkylphenol.   12. A method according to any one of the preceding claims, wherein the lubricating oil composition has a TBN of 4 to 100, preferably 5 to 75, more preferably 6 to 70, as measured by ASTM D2896.   13. The lubricating oil composition of any one of claims 1 to 12, wherein the lubricating oil composition is a marine cylinder lubricant, trunk piston engine oil, gas engine oil or crankcase lubricating oil composition (including passenger car motor oil and heavy duty diesel motor oil). the method of. Reduced basicity (measured according to ASTM D2896) of lubricating oil compositions (which contain at least one oil-soluble overbased alkali metal or alkaline earth metal detergent) for use in engines For reducing the speed of the formula (I):

(Where
x is 1 to 50, preferably 1 to 40, more preferably 1 to 30;
R ¹ and R ² are H, a hydrocarbyl group having 1 to 12 carbon atoms, or a hydrocarbyl group having 1 to 12 carbon atoms and at least one heteroatom,
R is a hydrocarbyl group having 9 to 100, preferably 9 to 70, most preferably 9 to 50 carbon atoms, and n is 0 to 10.
Or one or more alkaline earth metal salts thereof.

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