JP5828597B2 - Lubricating oil composition - Google Patents

Description

  The present invention generally relates to a method for reducing intake valve deposits in a direct injection spark ignition (DISI) engine. Also provided is a method for reducing intake valve deposits in a DISI engine by top-treating oil of lubricating viscosity with a lubricant additive concentrate.

  Recently, many automobile engine manufacturers have introduced direct injection spark ignition (DISI) engines for gasoline. Such engines inject gasoline directly into the combustion chamber of the engine, rather than indirectly introducing it through, for example, an intake manifold with a carburetor or port fuel injector. Since gasoline is directly injected into the combustion chamber, the amount of fuel burned and the timing of injection can be accurately controlled. However, one drawback of this approach is that there is no gasoline at the intake valve location to provide deposit control additives to remove deposits and deposit precursors, so the intake valve of the DISI engine It is easy to form intake valve deposits (hereinafter referred to as “IVD”). These valve deposits interfere with valve operation, reduce engine efficiency and adversely affect ease of operation.

  Some patent documents disclose the use of lubricant formulations to solve the problem of intake valve deposits in direct injection spark ignition engines.

  Konishi, Japanese Patent Publication No. 2003-155492 includes polybutenyl succinimide, dithiozinc phosphate (dithiozinc phosphate), phenol and / or amine group ashless antioxidant and alkaline earth metal group detergent. Although lubricants are disclosed, they do not contain a viscosity index improver.

  Calder, US Patent Publication No. 2004/0198614, is a method of reducing intake valve deposits in a direct injection engine comprising lubricating the engine with a lubricating oil composition comprising a base oil mixture comprising: The base oil mixture comprises (i) a Group III, Group IV oil, or mixture thereof in combination with (ii) a synthetic ester oil, wherein the weight ratio of (i) to (ii) is from about 0.2: 1 to about The above method is disclosed up to 6: 1.

  US Patent Publication No. 2004/0231632 describes an injection manifold deposit (such as including an intake valve valve) in a combustion engine by delivery of an organomolybdenum source from the gas phase of the engine lubricant to the combustion chamber. ), And a method and combustion system for reducing the formation of exhaust valve deposits.

  Adams et al., US Patent Publication No. 2005/0236301, (a) separates the fraction into a light base oil precursor fraction and a heavy base oil precursor fraction by distillation; and (b) separates each. The pour point of the base oil precursor fraction is reduced by dewaxing and (c) the partial isomerization by isolating the desired base oil product from the dewaxed oil fraction obtained in step (b). Discloses a method for preparing heavy and light lubricating base oils from a Fischer-Tropsch derived feedstock, which feedstock has an initial boiling point of less than 400 ° C and a final boiling point of more than 600 ° C.

  Wedlock, US Publication No. 2006/0052252, is a lubricant composition comprising a mixture of at least two Fischer-Tropsch derived base oils and one or more additives, which is a type of Fischer-Tropsch derived The above-mentioned lubrication wherein the base oil (low viscosity component) has a kinematic viscosity of less than 7 cSt at 100 ° C. and the second Fischer-Tropsch derived base oil (high viscosity component) has a kinematic viscosity of higher than 18 cSt at 100 ° C. An agent composition is disclosed.

  Locke et al., US Patent Publication No. 2007/0197406, is a lubricant that is substantially free of ashless organic friction modifiers, wherein the base oil has a Noack volatility of less than 12% by weight. It is disclosed that lubricating the engine with an agent reduces intake valve deposits in a direct injection internal combustion engine.

  Many patent documents disclose the use of defoamers in a general manner in gasoline direct injection engines. Examples of these include US Patent Publication Nos. 2008/0234153, 2008/0248981, and 2008/0110799, and Japanese Patent Publication No. 2008-120908, No. 2001-262172, 2008-231192, and 2008-231191.

  As mentioned above, intake valve deposits are recognized as a problem in DISI engines. Many attempts have been made to solve the problem of reducing intake valve deposits in DISI engines.

One aspect of the present invention is a method for reducing intake valve deposits in a direct injection spark ignition engine comprising: (a) a major amount of oil of lubricating viscosity; and (b) silicone oil, poly Operating the engine with a lubricating oil composition comprising at least one antifoaming agent selected from the group consisting of siloxane, polyacrylate, and polymethacrylate,
The antifoaming agent is not poly (phenylmethyl) siloxane and the amount of antifoaming agent in the lubricating oil composition is greater than operating the engine with a lubricating oil composition without the antifoaming agent. The above method is a concentration effective to achieve at least a 10% reduction in intake valve deposits in a direct injection spark ignition engine.

Another aspect of the present invention is a method for reducing intake valve deposits in a direct injection spark ignition engine, the method comprising: (a) operating the engine with lubricating oil;
(B) top treating the lubricating oil composition with a lubricating oil concentrate comprising at least one antifoam selected from the group consisting of silicone oil, polysiloxane, polyacrylate, and polymethacrylate, thereby top treating Providing a lubricating oil composition,
The antifoam is not poly (phenylmethyl) siloxane and the amount of the antifoam in the top-treated lubricating oil composition is sufficient to operate the engine with the lubricant of step (a) without the top treatment. Compared to the above method, which is an effective concentration to achieve at least a 10% reduction in intake valve deposits in the direct injection spark ignition engine.

  In another aspect, the lubricating oil composition disclosed herein further comprises an antioxidant, an antiwear agent, a cleaning agent, a rust inhibitor, a demulsifier, a friction modifier, an extreme pressure agent, a viscosity index improver, It includes at least one additive selected from the group consisting of pour point depressants, dispersants, corrosion inhibitors, and combinations thereof.

Definitions The term "top treat" means adding a lubricating oil concentrate described herein crankcase oil already present in DISI engines.

DETAILED DESCRIPTION OF THE INVENTION Among other factors, the present invention adds a greater amount of antifoam additive to a lubricant used to lubricate a direct injection gasoline engine when the amount is greater than typical. It is based on the surprising discovery that the amount of intake valve deposits in the engine can be substantially reduced. Typical amounts of antifoam additives used in many lubricants vary from about 5 to about 30 ppmw. The amount of defoamer added is very small and IVD deposits without the use of expensive specialty lubricants or base oils such as poly α-olefin (Group IV) or ester (Group V) lubricants Enables a significant reduction in This discovery also allows a small amount of antifoam booster to be added after service to gasoline direct injection engines lubricated with conventional lubricants.

According to one aspect of the present invention, there is provided herein a method for reducing intake valve deposits in a direct injection spark ignition engine comprising: (a) a major amount of oil of lubricating viscosity; And (b) operating the engine with a lubricating oil composition comprising at least one antifoaming agent selected from the group consisting of silicone oil, polysiloxane, polyacrylate, and polymethacrylate,
The antifoaming agent is not poly (phenylmethyl) siloxane and the amount of antifoaming agent in the lubricating oil composition is greater than operating the engine with a lubricating oil composition without the antifoaming agent. The above method is presented with an effective concentration to achieve at least a 10% reduction in intake valve deposits in a direct injection spark ignition engine.

In accordance with another aspect of the present invention, there is provided herein a method for reducing intake valve deposits in a direct injection spark ignition engine comprising: (a) operating the engine with lubricating oil. ,
(B) top treating the lubricating oil composition with a lubricating oil concentrate comprising at least one antifoam selected from the group consisting of silicone oil, polysiloxane, polyacrylate, and polymethacrylate, thereby top treating Providing a lubricating oil composition,
The antifoaming agent is not poly (phenylmethyl) siloxane and the amount of the antifoaming agent in the top-treated lubricating oil composition is compared to operating the engine in a lubricating oil step (a) without top-treating. Thus, the above method is presented which is an effective concentration to achieve at least a 10% reduction in intake valve deposits in the direct injection spark ignition engine.

  In one aspect of the invention, the direct injection spark ignition engine is an engine with positive pressure crankcase ventilation. Positive pressure crankcase ventilation is a method for reducing engine exhaust, in which the combustion gas that leaks from the combustion chamber to the crankcase via the piston and piston ring (often referred to as “blow-by”) The so-called blow-through) returns to the combustion chamber via the intake manifold, where the recirculated hydrocarbons are combusted.

Oil of lubricating viscosity:
Oils of lubricating viscosity for use in the lubricating oil compositions of the present invention are also referred to as base oils and are typically in major amounts in the composition, for example 50% by weight, based on the total weight of the composition. Higher amounts, preferably greater than about 70% by weight, more preferably from about 80% to about 99.5% by weight, most preferably from about 85% to about 98% by weight. Exists. As used herein, the expression “base oil” is produced by a single manufacturer with the same specifications (regardless of the feedstock and the location of the manufacturer), conforms to the same manufacturer's specifications, and is a single Should be understood to mean a base stock or a blend of base stocks that is a lubricating component identified by the formulation, manufacturing ID number, or both.

  Base oils for use in the present invention incorporate lubricating oil compositions for any and all applications such as functional fluids such as engine oil, marine cylinder oil, hydraulic oil, gear oil, transmission oil, etc. It can be an oil of currently known or later discovered lubricating viscosity used in the process. The selection of a particular base oil depends on the intended application of the lubricant and the presence of other additives. For example, oils of lubricating viscosity useful in the practice of the present invention can range in viscosity from light distilled mineral oils such as gasoline engine oils, mineral oil lubricants, and heavy vehicle diesel oils to heavy lubricants. Also, the base oil for use in the present invention can optionally include viscosity index improvers such as polymeric alkyl methacrylates, olefinic copolymers such as ethylene-propylene copolymers or styrene-butadiene copolymers, and mixtures thereof. . The lubricating oil composition of the present invention mixes an appropriate amount of the antifoam compound disclosed herein into an additive concentrate having an oil of lubricating viscosity and a conventional lubricating oil additive by conventional methods. Can be prepared.

  As one skilled in the art will readily appreciate, the viscosity of the base oil depends on the application. Accordingly, the viscosity of base oils for use in the present invention typically ranges from about 2 to about 2000 centistokes (cSt) at 100 degrees Celsius (° C.). In general, the base oils used as engine oils individually have kinematic viscosities at 100 ° C. ranging from about 2 cSt to about 30 cSt, preferably from about 3 cSt to about 16 cSt, most preferably from about 4 cSt to about 12 cSt, with the desired end purpose. And blended with additives in the finished oil to give the desired grade of engine oil. For example, 0W, 0W-20, 0W-30, 0W-40, 0W-50, 0W-60, 5W, 5W-20, 5W-30, 5W-40, 5W-50, 5W-60, 10W, 10W- A lubricating oil composition having a SAE viscosity grade of 20, 10W-30, 10W-40, 10W-50, 15W, 15W-20, 15W-30 or 15W-40. The oil used as the gear oil can have a viscosity ranging from about 2 cSt to about 2000 cSt at 100 ° C.

  Base stocks can be made in a variety of different ways, including but not limited to distillation, solvent purification, hydrotreating, oligomerization, esterification, and repurification. The re-purified stock should be substantially free of material introduced by manufacturing, contamination, or previous use. The base oil of the lubricating oil composition of the present invention may be a natural lubricating base oil or a synthetic lubricating base oil. Suitable hydrocarbon synthetic oils include oils prepared from ethylene polymerization or 1-olefin polymerization to provide polymers such as poly alpha-olefins and PAO oils, or carbon monoxide such as the Fischer-Tropsch process. Oils prepared from hydrocarbon synthesis procedures using hydrogen gas include, but are not limited to. For example, suitable base oils are those that contain little if any heavy fraction, for example, those that contain little if any lubricating oil fraction with a viscosity of 20 cSt or higher at 100 ° C.

  The base oil may be derived from natural lubricating oil, synthetic lubricating oil or mixtures thereof. Suitable base oils include not only base stocks obtained by isomerization of synthetic waxes and slack waxes, but also hydrogenation produced by hydrocracking (rather than solvent extraction) of crude aromatic and polar components. Decomposed base stock. Suitable base oils include those of all API categories I, II, III, IV, and V as defined in API standard 1509, 14th edition, Appendix I, December 1998. Group IV base oils are poly α-olefins (PAO). Group V base oils include all other base oils not included in Group I, II, III or IV.

  As shown herein, an advantage of the present invention is that small amounts of IVD can be obtained without using large amounts of expensive Group IV or Group V base stock. Thus, in one embodiment of the invention, the oil of lubricating viscosity comprises at least 50% by weight of Group III base stock. In another aspect of the invention, the oil of lubricating viscosity comprises at least 50% by weight of API Group II base stock. In a further aspect of the invention, the oil of lubricating viscosity comprises at least 50% by weight of a mixture of Group II and Group III base stocks. In one embodiment of the invention, the oil of lubricating viscosity does not include any Group IV or Group V base stock. In one embodiment of the invention, the base oil is a mixture of Group II, Group III, and Group IV base stocks.

  Natural oils can also be used, for example liquid petroleum, paraffin, naphthene or mixed paraffin-naphthene type solvent-treated or acid-treated mineral lubricants, coal or shale-derived oils, animal oils, vegetable oils (eg rapeseed oil, castor Oil, lard oil) and the like.

  Synthetic lubricating oils can also be used, polymerized olefins and internally polymerized olefins such as polybutylene, polypropylene, propylene-isobutylene copolymers. Hydrocarbon and halogen-substituted hydrocarbon oils such as chlorinated polybutylene, poly (1-hexene), poly (1-octene), poly (1-decene) and the like and mixtures thereof; dodecylbenzene, tetradecylbenzene, di Alkylbenzenes such as nonylbenzene, di (2-ethylhexyl) benzene, etc .; polyphenyls such as biphenyl, terphenyl, alkylated polyphenyl, etc .; alkylated diphenyl ethers and alkylated diphenyl sulfides and their derivatives, analogs and homologs However, it is not limited to these.

  Other synthetic lubricating oils used include oils made by polymerizing olefins of less than 5 carbon atoms, such as ethylene, propylene, butylene, isobutene, pentene, and mixtures thereof. Is not limited. Methods for preparing such polymer oils are well known to those skilled in the art.

Additional synthetic hydrocarbon oils used include liquid polymers of alpha olefins with appropriate viscosity. Particularly useful synthetic hydrocarbon oils are hydrogenated liquid oligomers of C _{6 to} C ₁₂ α-olefins such as 1-decent trimer.

Other classes of synthetic lubricating oils include, but are not limited to, alkylene oxide polymers, i.e. homopolymers, internal polymers, and derivatives thereof whose terminal hydroxyl groups have been modified, for example, by esterification or etherification. Illustrative of these oils are oils prepared by the polymerization of ethylene oxide or propylene oxide, these polyoxyalkylene polymers (eg, methylpolypropylene glycol having an average molecular weight of 1000, polyethylene glycol having a molecular weight of 500 to 1000 diphenyl ether of polypropylene diethyl ether glycol) or mono- and polycarboxylic esters having a molecular weight of 1000 to 1500, for example, the acetic acid esters, mixed _C 3 -C ₈ aliphatic ester, or _{C 13} oxo acid tetraethylene glycol Diesters may be mentioned.

  Still other classes of synthetic lubricants include dicarboxylic acids such as phthalic acid, succinic acid, alkyl succinic acid, alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid Examples include esters of dimer, malonic acid, alkylmalonic acid, alkenylmalonic acid and the like with various alcohols such as butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol and the like. However, it is not limited to these. Specific examples of these esters include dibutyl adipate, di (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, phthalic acid Didecyl, diecosyl sebacate, 2-ethylhexyl diester of linoleic acid dimer, complex ester formed by reacting 1 mol of sebacic acid, 2 mol of tetraethylene glycol and 2 mol of 2-ethylhexanoic acid, etc. .

  Esters can also be used as synthetic oils, such as carboxylic acids and alcohols having about 5 to about 12 carbon atoms, such as methanol, ethanol, neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, Examples include, but are not limited to, those obtained from polyols and polyol ethers such as tripentaerythritol.

  Silicone-based oils, such as polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils, and silicate ester oils, include other classes of synthetic lubricating oils that can be used in the present invention. Specific examples of these include tetraethyl silicate, tetraisopropyl silicate, tetra- (2-ethylhexyl) silicate, tetra- (4-methylhexyl) silicate, and tetra- (p-tert-butylphenyl silicate). ), Hexyl- (4-methyl-2-pentoxy) disiloxane, poly (methyl) siloxane, poly (methylphenyl) siloxane, and the like, but are not limited thereto.

  The lubricating oil may be derived from a mixture of two or more of non-refined, refined and re-refined oils, natural or synthetic or any of the types disclosed above. Unrefined oils are those obtained directly from natural or synthetic sources (eg, coal, shale, or tar sand bitumen) without further purification or processing. Examples of non-refined oils include, but are not limited to, shale oil obtained directly from retort harvesting operations, petroleum oil obtained directly from distillation, or ester oil obtained directly from an esterification process. It is then used without further processing. Refined oils are similar to non-refined oils except that they are further processed in one or more purification steps to improve one or more properties. These purification techniques are known to those skilled in the art and include, for example, solvent extraction, secondary distillation, acid or base extraction, filtration, leaching, hydrotreating, dewaxing, and the like. Rerefined oil is obtained by treating spent oil in a manner similar to that used to obtain refined oil. Such rerefined oils are also known as reclaimed or reprocessed oils and are often additionally processed by techniques directed to the removal of spent additives and oil breakdown products.

  Lubricating oil base stocks derived from the hydroisomerization of waxes can also be used alone or in combination with the natural and / or synthetic base stocks described above. Such wax isomerate oils are produced with hydroisomerization catalysts by hydroisomerization of natural or synthetic waxes or mixtures thereof.

  Natural waxes are typically slack waxes (soft waxes) recovered by solvent dewaxing of mineral oil. Synthetic waxes are typically waxes produced by the Fischer-Tropsch process.

Antifoam:
An antifoaming agent is a lubricant additive that, when added in a small amount to a lubricant, suppresses foam formation and / or promotes foam breakage. At least one antifoam or mixture thereof is used in the lubricating oil composition of the present invention. The antifoam used is selected from the group consisting of silicone oil, polysiloxane, polyacrylate, polymethacrylate, and combinations thereof, provided that the antifoam is not poly (phenyl-methyl) siloxane.

  In one embodiment, the antifoaming agent is polydimethylsiloxane.

  In one embodiment, the antifoaming agent is poly (dimethyl, phenyl-methyl) siloxane. In one embodiment, the antifoaming agent is a mixture of polydimethylsiloxane and poly (dimethyl, phenyl-methyl) siloxane.

  In one embodiment, the antifoaming agent is polymethacrylate.

  In one embodiment, the antifoaming agent is poly (trifluoropropylmethyl) siloxane.

  In one embodiment, the amount of antifoam in the lubricating oil composition is from about 30 to about 500 ppmw, or from about 50 to about 500 ppmw, or from about 75 to about 500 ppmw, or from about the total weight of the lubricating oil composition It can vary from 100 to about 500 ppmw, or from about 150 to about 500 ppmw, or from about 200 to about 400 ppmw.

  In one aspect, the reduction in intake valve deposits is at least 10%, or at least 20%, or at least 30%, or at least 40% compared to operating the engine with a lubricant composition without an antifoam. Or at least 50%.

  In one embodiment, the amount of antifoam in the lubricating oil concentrate is from about 0.01% to about 1%, from about 0.02% to about 0.8%, based on the total weight of the lubricating oil concentrate. % By weight, from about 0.03% to about 0.7% by weight, or from about 0.04% to about 0.6% by weight. The antifoaming agent can be conveniently added to the lubricating oil concentrate in the form of an antifoaming concentrate comprising an antifoaming agent and at least one solvent.

Additional lubricant additives:
The lubricating oil composition of the present invention may include other conventional additives to impart a preliminary function, giving a final lubricating oil composition in which these additives are dispersed or dissolved. For example, lubricating oil compositions are antioxidants, antiwear agents, ashless dispersants, cleaning agents, rust inhibitors, antifouling agents, demulsifiers, metal deactivators, friction modifiers, pour point depressants, cosolvents, It can be blended with package compatibilizers, corrosion inhibitors, dyes, extreme pressure agents, etc., and combinations thereof. Various additives are known and commercially available. These additives or similar compounds can be used in the preparation of the lubricating oil composition of the present invention by conventional blending procedures.

  Examples of antioxidants include amine types such as diphenylamine, phenyl-α-naphthyl-amine, N, N-di (alkylphenyl) amine; alkylated phenylene-diamines; phenol types such as BHT, sterically hindered alkylphenols such as 2 , 6-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, and 2,6-di-tert-butyl-4- (2-octyl-3-propanoic) phenol; and mixtures thereof For example, but not limited to.

  Examples of antiwear agents are zinc dialkyldithiophosphates, zinc diaryldithiophosphates, such as Born et al., Title “Relationship between Chemical Structure and Effect of the Thy thiol sir ti s i n ti s i n ti s i n i n e n i n e n i n e n i n e n i n e n i n e n i n e n i n e n i n i n e n i n e n i n i n i n i n i n i n i n i n i n i n i n i n i n i n i n i n i n i n i n i n i n i n i n i n. Relation between chemical structure and effectiveness of dialkyl- and diaryl-dithiophosphate metals), Lubrication Science 4-2 January 1992, eg see pages 97-100; arylphosphates and phosphites, sulfur Contained beauty treatment salon , Rin'iou compounds, dithiocarbamate metal or ashless, xanthates, alkyl sulfides and the like, and mixtures thereof, but not limited to.

  Representative examples of ashless dispersants include, but are not limited to, polar moieties attached to the polymer backbone through amines, alcohols, amides, or crosslinking groups. The ashless dispersant of the present invention includes, for example, oil-soluble salts, esters, aminoesters, amides, imides, and oxazolines or anhydrides of mono- and dicarboxylic acids substituted with long-chain hydrocarbons; thiocarboxylates of long-chain hydrocarbons It may be selected from derivatives, long chain aliphatic hydrocarbons directly linked to polyamines; and Mannich condensation products formed by condensing long chain substituted phenols with formaldehyde and polyalkylene polyamines.

  The carboxyl group-containing dispersant comprises a carboxyl group-containing acylating agent (acid, anhydride, ester, etc.) containing at least about 34, preferably at least about 54 carbon atoms, a nitrogen-containing compound (eg amine), organic hydroxy Reaction products with compounds (eg aliphatic compounds including mono- and polyhydric alcohols or aromatic compounds including phenol and naphthol) and / or basic inorganic materials. These reaction products include imides, amides, and esters.

  A succinimide dispersant is a kind of a carboxyl group-containing dispersant. These are prepared by reacting a hydrocarbyl-substituted succinic acylating agent with an organic hydroxy compound, or an amine containing at least one hydrogen atom bonded to a nitrogen atom, or a mixture of a hydroxy compound and an amine. Is done. The term “succinic acylating agent” refers to a hydrocarbon-substituted succinic acid or succinic acid-generating compound, the latter also including the acid itself. Such materials typically include hydrocarbyl substituted succinic acids, anhydrides, esters (including half esters) and halides.

（式中、各Ｒ^１は独立にヒドロカルビル基、例えばポリオレフィン由来の基である。）
により表すことができる。典型的には、ヒドロカルビル基はアルキル基、例えばポリイソブチル基である。別の表現をすれば、Ｒ^１基は約４０個〜約５００個の炭素原子を含むことができ、これらの原子は脂肪族形態で存在してもよい。Ｒ^２はアルキレン基であり、通常はエチレン（Ｃ_２Ｈ_４）基である。スクシンイミド分散剤の例としては、例えば、米国特許第３，１７２，８９２号、第４，２３４，４３５号、及び第６，１６５，２３５号明細書に記載されたものが挙げられる。 Succinic acid-based dispersants have a wide variety of chemical structures. One class of succinic acid-based dispersants has the formula:

(In the formula, each R ¹ is independently a hydrocarbyl group, for example, a group derived from polyolefin.)
Can be represented by Typically, the hydrocarbyl group is an alkyl group, such as a polyisobutyl group. In other words, the R ¹ group can contain from about 40 to about 500 carbon atoms, which can be present in aliphatic form. R ² is an alkylene group, usually an ethylene (C ₂ H ₄ ) group. Examples of succinimide dispersants include those described in US Pat. Nos. 3,172,892, 4,234,435, and 6,165,235.

  The polyalkene from which the substituent is derived is typically homopolymers and interpolymers of polymerizable olefin monomers of 2 to about 16 carbon atoms, usually 2 to 6 carbon atoms. The amine that reacts with the succinic acylating agent to form the carboxyl group-containing dispersant composition can be a monoamine or a polyamine.

  Succinimide dispersants are usually referred to as such because they contain nitrogen primarily in the form of imide functional groups, although amide functional groups may exist in the form of amine salts, amides, imidazolines, and mixtures thereof. Good. To prepare the succinimide dispersant, one or more succinic acid-generating compounds and one or more amines are heated, typically water, optionally in the presence of a substantially inert organic liquid solvent / diluent. Remove under. The reaction temperature ranges from about 80 ° C. to the decomposition temperature of the mixture or product, which is typically between about 100 ° C. and about 300 ° C. For further details and examples of procedures for preparing the succinimide dispersants of the present invention, see, for example, U.S. Pat. Nos. 3,172,892, 3,219,666, 3,272,746, fourth. , 234,435, 6,165,235, and 6,440,905.

  Suitable ashless dispersants may include amine dispersants, which are the reaction product of a relatively high molecular weight aliphatic halide and an amine, preferably a polyalkylene polyamine. Examples of such amine dispersants include, for example, U.S. Pat. Nos. 3,275,554, 3,438,757, 3,454,555, and 3,565,804. Those described are mentioned.

  Further suitable ashless dispersants may include “Mannich dispersants”, which include alkylphenols whose alkyl groups contain at least about 30 carbon atoms, aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines). The reaction product of Examples of such amine dispersants include, for example, U.S. Pat. Nos. 3,036,003, 3,586,629, 3,591,598, and 3,980,569. Those described are mentioned.

  Suitable ashless dispersants may also be post-treated ashless dispersants such as post-treated succinimide, for example, post-treatment methods such as US Pat. Nos. 4,612,132, and 4, Examples include those involving borate or ethylene carbonate disclosed in US Pat. No. 746,446, as well as other post-treatment methods. The carbonated alkenyl succinimide has a molecular weight of about 450 to about 3000, preferably about 900 to about 2500, more preferably about 1300 to about 2400, most preferably about 2000 to about 2400, as well as mixtures of these molecular weights. Polybutene succinimide derived from polybutene having It preferably comprises, under reactive conditions, a polybutene succinic acid derivative, an unsaturated acidic reagent copolymer of an unsaturated acidic reagent and an olefin, and a polyamine such as US Pat. No. 5,716,912 (see this content). By reacting a mixture of such as disclosed in the present specification.

  Suitable ashless dispersants may also be polymeric, which is an interpolymer of oil soluble monomers such as decyl methacrylate, vinyl decyl ether, and high molecular weight olefins with monomers containing polar substituents. Examples of the polymeric dispersant include those described in US Pat. Nos. 3,329,658, 3,449,250, and 3,666,730.

  In one preferred embodiment of the invention, the ashless dispersant for use in the lubricating oil composition is a bissuccinimide derived from a polyisobutenyl group having a number average molecular weight of about 700 to about 2300. The dispersant for use in the lubricating oil composition of the present invention is preferably non-polymeric (eg, mono- or bis-succinimide).

  Generally, the one or more ashless dispersants are present in the lubricating oil composition in an amount ranging from about 0.01% to about 10% by weight relative to the total weight of the lubricating oil composition.

Representative examples of metal detergents include sulfonates, alkyl phenates, sulfurized alkyl phenates, carboxylates, salicylates, phosphonates, and phosphinates. Commercial products are commonly referred to as neutral or overbased. Overbased metal detergents are generally hydrocarbons, detergent acids such as: sulfonic acids, alkylphenols, carboxylates, metal oxides or hydroxides (eg calcium oxide or calcium hydroxide) and xylene, Produced by carbonating a mixture of a promoter such as methanol and water. For example, to prepare an overbased calcium sulfonate by carbonation, oxidation or calcium hydroxide is reacted with gaseous carbon dioxide to form calcium carbonate. The sulfonic acid is neutralized with excess CaO or Ca (OH) ₂ to form the sulfonate salt.

  Metal-containing or ash-forming cleaning agents function as cleaning agents to reduce or remove deposits and as acid neutralizers or rust inhibitors, thereby reducing wear and corrosion and extending engine life. Detergents generally comprise a polar head with a long, hydrophobic tail. The polar head contains a metal salt of an acidic organic compound. The salt may contain a substantially stoichiometric amount of metal, in which case the salt is usually described as a normal or neutral salt, typically having a total base number of 0 to about 80 or With TBN (as measured by ASTM D2896). Large amounts of metal base may be introduced by reacting excess metal compound (eg, oxide or hydroxide) with acid gas (eg, carbon dioxide). The resulting overbased detergent contains a neutral detergent as the outer layer of a metal base (eg carbonate) micelle. Such overbased detergents can have a TBN of about 150 or more, and typically will have a TBN of about 250 to about 450 or more.

  Detergents that can be used include oil-soluble neutral and overbased sulfonates, phenates, metals, especially alkali or alkaline earth metals (eg, barium, sodium, potassium, lithium, calcium, and magnesium). Sulfurized phenates, thiophosphonates, salicylates, and naphthenates, as well as other oil soluble carboxylates. The most commonly used metals are calcium and magnesium (which may both be present in the detergent used in the lubricant), and a mixture of calcium and / or magnesium and sodium. Particularly advantageous metal detergents are neutral and overbased calcium sulfonates having a TBN of about 20 to about 450, neutral and overbased calcium phenates and sulfurized phenates having a TBN of about 50 to about 450, And neutral and overbased magnesium or calcium salicylates having a TBN of about 20 to about 450. Combinations of detergents can be used, either overbased, neutral or both.

  In one embodiment, the cleaning agent can be one or more of an alkali or alkaline earth metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid. Suitable hydroxyaromatic compounds include mononuclear monohydroxy and polyhydroxy aromatic hydrocarbons having 1 to 4, preferably 1 to 3 hydroxyl groups. Suitable hydroxy aromatic compounds include phenol, catechol, resorcinol, hydroquinone, pyrogallol, cresol and the like. A preferred hydroxyaromatic compound is phenol.

  The alkyl-substituted moiety of the alkali or alkaline earth metal salt of the alkyl-substituted hydroxyaromatic carboxylic acid is derived from an α-olefin having from about 10 to about 80 carbon atoms. The olefin used may be linear, isomerized linear, branched or partially branched linear. The olefin may be a mixture of linear olefins, a mixture of isomerized linear olefins, a mixture of branched olefins, a partially branched linear mixture, or any mixture described above.

  In one embodiment, the mixture of linear olefins that can be used is a mixture of linear α-olefins selected from olefins having from about 12 to about 30 carbon atoms per molecule. In one embodiment, the linear α-olefin is isomerized using at least one solid or liquid catalyst.

  In one embodiment, the olefin is a branched olefinic propylene oligomer or mixture thereof having from about 20 to about 80 carbon atoms, ie, a branched olefin derived from the polymerization of propylene. The olefin may also be substituted with other functional groups such as hydroxyl groups, carboxylic acid groups, heteroatoms and the like. In one embodiment, the branched olefinic propylene oligomer or mixture thereof has from about 20 to about 60 carbon atoms. In one embodiment, the branched olefinic propylene oligomer or mixture thereof has from about 20 to about 40 carbon atoms.

In one embodiment, at least about 75 of the alkyl groups contained within an alkali or alkaline earth metal salt of an alkyl substituted hydroxyaromatic carboxylic acid, such as an alkyl group of an alkaline earth metal salt of an alkyl substituted hydroxybenzoic acid detergent. mol% (e.g., at least about 80 mole%, at least about 85 mole%, at least about 90 mole%, at least about 95 mole%, or at least about 99 mole%) _{is C 20} or greater. In another aspect, the alkali or alkaline earth metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid is a residue of a linear α-olefin in which the alkyl group comprises at least 75 mol% C ₂₀ or higher linear α-olefin. Alkali or alkaline earth metal salts of alkyl-substituted hydroxybenzoic acids derived from certain alkyl-substituted hydroxybenzoic acids.

In other embodiments, at least about 50 of the alkyl groups contained within the alkali or alkaline earth metal salt of the alkyl-substituted hydroxyaromatic carboxylic acid, such as the alkyl group of an alkali- or alkaline earth metal salt of an alkyl-substituted hydroxybenzoic acid. Mol% (e.g., at least about 60 mol%, at least about 70 mol%, at least about 80 mol%, at least about 85 mol%, at least about 90 mol%, at least about 95 mol%, or at least about 99 mol%) about a _{C 14} ~ about _{C 18.}

  The resulting alkali or alkaline earth metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid will be a mixture of ortho and para isomers. In one embodiment, the product will contain about 1-99% ortho isomer and 99-1% para isomer. In other embodiments, the product will contain about 5-70% ortho and 95-30% para isomer.

  Alkali or alkaline earth metal salts of alkyl-substituted hydroxyaromatic carboxylic acids can be neutral or overbased. In general, an overbased alkali or alkaline earth metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid is obtained by converting the BN of an alkali- or alkaline earth metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid to a base source (eg, lime) and an acidic peroxide. It is increased by a method such as addition of a basic compound (for example, carbon dioxide).

  The overbased salt can be an overbased salt that is low overbased, eg, having a BN of less than about 100. In one embodiment, the BN of the low overbased salt can be from about 5 to about 50. In other embodiments, the BN of the low overbased salt can be from about 10 to about 30. In yet another aspect, the BN of the low overbased salt can be from about 15 to about 20.

  The overbased detergent can be moderately overbased, for example, an overbased salt having a BN of about 100 to about 250. In one embodiment, the BN of the moderately overbased salt is about 100 to about 200. In other embodiments, the BN of the moderately overbased salt is from about 125 to about 175.

  The overbased detergent may be highly overbased, for example, an overbased salt having a BN greater than about 250. In one embodiment, the BN of the highly overbased salt is from about 250 to about 450.

  Sulfonates are prepared from sulfonic acids typically obtained from petroleum fractions or by sulfonation of alkyl-substituted aromatic hydrocarbons, such as those obtained by alkylation of aromatic hydrocarbons. Examples include those obtained by alkylating benzene, toluene, xylene, naphthalene, diphenyl, or their halogen derivatives. Alkylation can be carried out in the presence of a catalyst with an alkylating agent having from about 3 to more than 70 carbon atoms. The alkaryl sulfonate typically 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 can be neutralized with metal oxides, hydroxides, alkoxides, carbonates, carboxylates, sulfides, hydrosulfides, nitrates, borates, and ethers. The amount of metal compound is selected with respect to the desired TBN of the final product, but typically ranges from about 100 to about 200% by weight (preferably at least about 125% by weight) of what is required stoichiometrically. Across.

  Metal salts of phenol and sulfurized phenol are prepared by reaction with appropriate metal compounds such as oxides and hydroxides, and neutral or overbased products can be obtained by methods well known in the art. . Sulfurized phenols are a mixture of compounds in which two or more phenols are generally crosslinked by a sulfur-containing bridge by reacting the phenol with sulfur or a sulfur-containing compound such as hydrogen sulfide, sulfur monohalide, or sulfur dihalide. Can be prepared by forming a product.

  In general, the one or more detergents are present in the lubricating oil composition in an amount ranging from about 0.01% to about 10% by weight relative to the total weight of the lubricating oil composition.

  Examples of rust inhibitors include nonionic polyoxyalkylene agents such as polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene octyl stearyl. Ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol monooleate, and polyethylene glycol monooleate; stearic acid and other fatty acids; dicarboxylic acids; metal soaps; fatty acid amine salts; Metal salt of sulfonic acid; partial carboxylic acid ester of polyhydric alcohol; phosphate ester; (short chain) alkenyl succinic acid; its partial ester and its nitrogen-containing derivative; Ca reel sulfonates, for example, metal dinonylnaphthalene sulfonates; and the like, as well as mixtures thereof, but not limited to.

Examples of friction modifiers include: alkoxylated aliphatic amines; borated aliphatic epoxides; aliphatic phosphites, aliphatic epoxides, aliphatic amines, borated alkosylated fatty amines, fatty acid metal salts, fatty acid amides, glycerol esters, borated glycerol esters; and U.S. Patent No. 6,372,696 (the contents of which are incorporated herein by reference.) in the disclosed aliphatic imidazoline; C ₄ ~ Obtained from reaction products of C ₇₅ , preferably C ₆ -C ₂₄ , and most preferably C ₆ -C ₂₀ fatty acid esters, nitrogen-containing compounds selected from the group consisting of ammonia and alkanolamines, and mixtures thereof. Examples include, but are not limited to, friction modifiers and mixtures thereof.

  Examples of pour point depressants include polymethacrylate, alkyl acrylate polymer, alkyl methacrylate polymer, di (tetraparaffin phenol) phthalate, condensate of tetraparaffin phenol, condensate of chlorinated paraffin and naphthalene, and mixtures thereof. However, it is not limited to these. In one embodiment, the pour point depressant comprises an ethylene-vinyl acetate copolymer, a condensate of chlorinated paraffin and phenol, polyalkylstyrene, and the like, and mixtures thereof. The amount of pour point depressant can vary from about 0.01% to about 10% by weight.

  Examples of demulsifiers include anionic surfactants (eg, alkyl-naphthalene sulfonates, alkyl benzene sulfonates, etc.), nonionic alkoxylated alkylphenol resins, alkylene oxide polymers (eg, polyethylene oxide, polypropylene oxide, ethylene oxide, propylene oxide). Block copolymers), esters of oil-soluble acids, polyoxyethylene sorbitan esters, and the like, and combinations thereof, but are not limited thereto. The amount of demulsifier can vary from about 0.01% to about 10% by weight.

  Examples of rust inhibitors include, but are not limited to, dodecyl succinic acid half esters or amides, phosphate esters, thiophosphates, alkyl imidazolines, sarcosine, and combinations thereof. The amount of rust inhibitor can vary from about 0.01% to about 5% by weight.

  Examples of extreme pressure agents include sulfurized animal or vegetable oils, sulfurized animal or vegetable fatty acid esters, trivalent or pentavalent fully or partially esterified esters of phosphorus, sulfurized olefins, dihydrocarbyl polysulfides, sulfurized diels-alder adducts. , Sulfurized dicyclopentadiene, sulfurized or co-sulfurized mixture of fatty acid ester and monounsaturated olefin, fatty acid, fatty acid ester and α-olefin co-sulfurized blend, functional group-substituted dihydrocarbyl polysulfide, thiaaldehyde, thiaketone, epithio compound, sulfur-containing Examples include, but are not limited to, acetal derivatives, co-sulfurized blends of terpenes and acyclic olefins, and polysulfide olefin products, amine salts of phosphate esters or thiophosphate esters, and combinations thereof. The amount of extreme pressure agent can vary from about 0.01% to about 5% by weight.

  Each of the above-described additives, when used, is used in an amount that is functionally effective to impart the desired properties to the lubricant. Thus, for example, when the additive is a friction modifier, the functionally effective amount of the friction modifier is an amount sufficient to impart the desired friction modifying properties to the lubricant. In general, the concentration of each of these additives, if used, ranges from about 0.001% to about 20% by weight, based on the total weight of the lubricating oil composition, unless otherwise specified. In one embodiment, it ranges from about 0.01% to about 10% by weight.

  In another aspect of the present invention, the lubricating oil additive of the present invention can be provided as an additive package or concentrate, which additive is substantially inert, usually such as mineral oil, naphtha, benzene, toluene. Alternatively, it is introduced into a liquid organic diluent such as xylene to form an additive concentrate.

Concentrates and diluents:
Lubricating oil concentrates are also contemplated herein. These concentrates are typically at least about 90% to about 10%, or about 80% to about 20%, or about 70% to about 30%, or about 60% by weight. Up to about 40% by weight diluent oil, and from about 10% to about 90%, or from about 20% to about 80%, or from about 30% to about 70%, or about 40% by weight Up to about 60% by weight of the antifoam described in the lubricating oil composition of the present invention, or a combination thereof. Typically, the concentrate contains sufficient diluent to facilitate handling during shipping and storage. Suitable diluents for the concentrate include any inert diluent, but are preferably oils of lubricating viscosity, so that the concentrate can be easily mixed with the lubricating oil Product can be prepared. Suitable lubricating oils that can be used as diluents can be any lubricating viscosity oil, but typically from about 35 to about 500 Saybolt Universal Seconds (SUS) at 100 ° F. (38 ° C.). Viscosity in the range of

  If desired, other additives can be mixed with the lubricating oil concentrate described above to improve performance. Examples of these additives include antioxidants, antiwear agents, cleaning agents, rust inhibitors, demulsifiers, friction modifiers, extreme pressure agents, viscosity index improvements at normal levels according to well-known techniques Include, but are not limited to, agents, pour point depressants, dispersants, corrosion inhibitors, and the like.

  The antifoam agents of the present invention are also contemplated for use as a top treatment for crankcase lubricants used in DISI engines, along with other additional additives described herein. When so used, the top-treated lubricating oil concentrate is about 0.01 to 5% by weight of oil, or about 0.5 to about 2% by weight, based on the total weight of the lubricant composition. Can be added to the oil.

  In another aspect, the top treated lubricant concentrate is in the original DISI engine lubricant composition with a final concentration of the defoamer of the present invention of 150 and 500 ppmw relative to the total weight of the engine lubricant composition. And preferably in an amount such that it is between 200 and 400 ppmw.

  In one embodiment, the addition of the top treatment lube concentrate shows at least a 10% reduction in IVD compared to operating the engine with the lubricant without the top treatment lube concentrate.

  In one embodiment, the addition of the top treatment lubricant concentrate shows at least a 20% reduction in IVD compared to operating the engine with the lubricant without the top treatment lubricant concentrate.

  In one embodiment, the addition of the top treatment lube concentrate shows at least a 30% reduction in IVD compared to operating the engine with the lubricant without the top treatment lube concentrate.

  In one embodiment, the addition of the top treatment lubricant concentrate shows at least a 40% reduction in IVD compared to operating the engine with the lubricant without the top treatment lubricant concentrate.

  In one embodiment, the addition of the top treatment lubricant concentrate shows at least a 50% reduction in IVD compared to operating the engine with the lubricant without the top treatment lubricant concentrate.

Performance Test The lubricating oil compositions of Examples 1 and 2 below were evaluated using the 2001 Mitsubishi 1.8L DISI 212 hour intake valve deposit test ("Mitsubishi IVD Test") as described below. The 2001 Mitsubishi 1.8L DISI engine used for this procedure was installed on the engine stand and connected to a dynamometer while controlling the weight and speed. The Mitsubishi DISI engine is a wall-guided engine with the ability to perform both uniform and lean-stratified combustion. To perform the tests described herein, the engine was run in lean stratified combustion mode.

  The engine is first flushed with the oil to be tested, refilled with test oil and then run in a 30 minute test cycle. The engine is then stopped, the oil is drained, and a fresh sample of test oil is added to the engine. The 212 hour test is then started. This consists of approximately 636 test cycle repetitions. In the test cycle, the engine is operated at no load at idle speed (750 ± 150 rpm) for 1 minute, and then for 19 minutes at low load (20.0 N / m) and low speed (1400 ± 10 rpm). Stop engine at 106 hours, check oil level and add additional test oil to full mark if necessary.

  After 212 hours, the engine head is removed and the intake valve and combustion chamber deposit weights are evaluated. Rinse the engine eight intake valves (two per cylinder) with hexane and weigh. The intake valve is weighed before and after the test, and the difference in weight represents the weight of the deposit deposited during the test.

  The following non-limiting examples are intended to illustrate the present invention. The effect of using a high concentration of antifoam crankcase lubricant for direct injection spark ignition engines has been demonstrated by the 2001 Mitsubishi 1.8L DISI 212 hour intake valve deposit test ("Mitsubishi IVD Test") above. It was. All lubricants tested included dispersants, detergents, zinc dialkyldithiophosphates, amine antioxidants, friction modifiers, polymethacrylate pour point depressants, and olefin copolymer viscosity index improvers, but defoaming The same amount of additive in the “Baseline Additive Package” was included, with no additive added.

Group III Lubricant with Silicone Defoamer Mitsubishi IVD test, a lubricant containing a baseline additive package in approximately 75% by weight of Yubase 4 Group III base oil and varying the active ingredient concentration of various antifoams Went about. Antifoam A is poly (phenyl-methyl) siloxane; B is a mixture of polydimethylsiloxane and poly (dimethyl, phenyl-methyl) siloxane; C is polymethacrylate; D is poly (trifluoropropylmethyl) siloxane; and E is Poly (dimethyl, phenyl-methyl) siloxane was used. The results are shown in Table 1 below.

Table 1

  The results in Table 1 show the surprising effect of various antifoams on reducing the intake valve deposits of Group III lubricants.

Group II / Group III / Group IV lubricant Mitsubishi IVD test with silicone defoamer was tested for approximately 75% by weight, (1) 50% by weight PT100D Group II base oil, (2) 30% by weight Yubase 6 Group III base Oil and (3) a lubricant containing a baseline additive package in a mixture containing 20 wt% PAO8 Group IV base oil and varying the active ingredient concentration of antifoam B above. The results are shown in Table 2 below.

Table 2

  The results in Table 2 show that the mixed Group II / Group III / Group IV lubricant containing the antifoam of the present invention also results in a reduction in the amount of intake valve deposits.

BMW 5W30 lubricant top treated with antifoam agent:
The Mitsubishi IVD test was conducted with a commercial 5W30 lubricating oil top-treated with the above antifoam B at a concentration of 350 ppm active ingredient. The results are shown in Table 3 below.

Table 3

  The results in Table 3 show the surprising effect in reducing intake valve deposits by top treating the lubricant with a concentrate containing antifoam.

Claims (30)

A method for reducing intake valve deposits in a direct injection spark ignition engine comprising: (a) a major amount of oil of lubricating viscosity; and (b) silicone oil, polysiloxane, polyacrylate, and polymethacrylate. Operating the engine with a lubricating oil composition comprising at least one antifoam selected from the group consisting of:
The antifoaming agent is not poly (phenylmethyl) siloxane and the amount of antifoaming agent in the lubricating oil composition is greater than operating the engine with a lubricating oil composition without the antifoaming agent. The above method is a concentration effective to achieve at least a 10% reduction in intake valve deposits in a direct injection spark ignition engine.   2. A process according to claim 1, wherein the antifoaming agent is selected from polysiloxanes and polymethacrylates.   The antifoaming agent is selected from the group consisting of polydimethylsiloxane, poly (dimethyl, phenyl-methyl) siloxane, poly (trifluoropropylmethyl) siloxane, and a mixture of polydimethylsiloxane and poly (dimethyl, phenyl-methyl) siloxane. The method according to claim 1 or 2. The concentration of the antifoaming agent in the lubricating oil composition is, 3 is 0 to 5 00ppm w, method according to any one of claims 1 to 3. The concentration of the antifoaming agent in the lubricating oil composition is from 1 00 or et 5 00ppm w, method according to any one of claims 1 to 3. The concentration of the antifoaming agent in the lubricating oil composition is 1 50 or et 5 00ppm w, method according to any one of claims 1 to 3. The concentration of the antifoaming agent in the lubricating oil composition is from 2 00 or et 4 00Ppmw, method according to any one of claims 1 to 3. Reduction of intake valve deposits is at least 20% A method according to any one of claims 1-7. Reduction of intake valve deposits is at least 3 0% A method according to any one of claims 1-7. Reduction of intake valve deposits is at least 4 0% A method according to any one of claims 1-7. Reduction of intake valves deposits is at least 50% A method according to any one of claims 1-7. The lubricating oil composition further includes a cleaning agent, a dispersant, an antioxidant, an antiwear agent, an antirust agent, an anti-wrinkle agent, a demulsifier, a metal deactivator, a friction modifier, a pour point depressant, a cosolvent, The method according to any one of claims 1 to 11 , comprising at least one additive selected from the group consisting of package compatibilizers, corrosion inhibitors, dyes, extreme pressure agents, and mixtures thereof. Oil of the lubricating viscosity comprises a base stock, or a mixture thereof of at least 50 wt% of API Group II or Group III, Method according to any one of claims 1 to 12. A method for reducing intake valve deposits in a direct injection spark ignition engine comprising: (a) operating the engine with lubricating oil;
(B) top treating the lubricating oil with a lubricating oil concentrate comprising at least one antifoaming agent selected from the group consisting of silicone oil, polysiloxane, polyacrylate, and polymethacrylate, thereby top treating lubricating oil Providing a composition,
The antifoam is not poly (phenylmethyl) siloxane and the amount of the antifoam in the top-treated lubricating oil composition is sufficient to operate the engine with the lubricant of step (a) without the top treatment. In comparison, the above method is a concentration effective to achieve at least a 10% reduction in intake valve deposits in the direct injection spark ignition engine. The process according to claim 14 , wherein the antifoaming agent is selected from polysiloxanes and polymethacrylates. The antifoaming agent is selected from the group consisting of polydimethylsiloxane, poly (dimethyl, phenyl-methyl) siloxane, poly (trifluoropropylmethyl) siloxane, and a mixture of polydimethylsiloxane and poly (dimethyl, phenyl-methyl) siloxane. 16. A method according to claim 14 or 15 . The concentration of the antifoaming agent in the lubricating oil concentrate is 0 . 01 or et al. 1. The method according to any one of claims 14 to 16 , which is 0 % by weight. The concentration of the antifoaming agent in the lubricating oil concentrate is 0 . 02 or et al. 0. The method according to any one of claims 14 to 16 , which is 8 % by weight. The concentration of the antifoaming agent in the lubricating oil concentrate is 0 . 03 or et al. 0. The method according to any one of claims 14 to 16 , which is 7 % by weight. The concentration of the antifoaming agent in the lubricating oil concentrate is 0 . 04 or et al. 0. The method according to any one of claims 14 to 16 , which is 6% by weight. The final concentration of the defoamer top treat lubricating oil composition is, 3 is from 0 to 500 ppm w, method according to any one of claims 14-20. The final concentration of the antifoaming agent of the top processing lubricating oil composition is 1 00 or et 5 00ppm w, method according to any one of claims 14-20. The final concentration of the antifoaming agent of the top processing lubricating oil composition is 1 50 or et 5 00ppm w, method according to any one of claims 14-20. The final concentration of the defoamer top treat lubricating oil composition is from 2 00 or et 4 00Ppmw, method according to any one of claims 14-20. 25. A method according to any one of claims 14 to 24 , wherein the reduction of intake valve deposits is at least 20 % . 25. A method according to any one of claims 14 to 24 , wherein the reduction of intake valve deposits is at least 30 % . 25. A method according to any one of claims 14 to 24 , wherein the reduction of intake valve deposits is at least 40 % . Reduction of intake valve deposits is at least 50% A method according to any one of claims 14-24. The top treatment lubricating oil composition further comprises a cleaning agent, a dispersant, an antioxidant, an antiwear agent, a rust inhibitor, a wrinkle inhibitor, a demulsifier, a metal deactivator, a friction modifier, a pour point depressant, The method according to any one of claims 14 to 28 , comprising at least one additive selected from the group consisting of a solvent, a package compatibilizer, a corrosion inhibitor, a dye, an extreme pressure agent, and a mixture thereof. 30. A method according to any one of claims 14 to 29 , wherein the lubricating oil comprises at least 50% by weight of API Group II or Group III base stock, or mixtures thereof.